148-410: A nickel–metal hydride battery ( NiMH or Ni–MH ) is a type of rechargeable battery . The chemical reaction at the positive electrode is similar to that of the nickel–cadmium cell (NiCd), with both using nickel oxide hydroxide (NiOOH). However, the negative electrodes use a hydrogen-absorbing alloy instead of cadmium . NiMH batteries can have two to three times the capacity of NiCd batteries of
296-419: A "20-hour" rate), while typical charging and discharging may occur at C/2 (two hours for full capacity). The available capacity of electrochemical cells varies depending on the discharge rate. Some energy is lost in the internal resistance of cell components (plates, electrolyte, interconnections), and the rate of discharge is limited by the speed at which chemicals in the cell can move about. For lead-acid cells,
444-437: A battery charger using AC mains electricity , although some are equipped to use a vehicle's 12-volt DC power outlet. The voltage of the source must be higher than that of the battery to force current to flow into it, but not too much higher or the battery may be damaged. Chargers take from a few minutes to several hours to charge a battery. Slow "dumb" chargers without voltage or temperature-sensing capabilities will charge at
592-549: A fissile material . The principal sources of rare-earth elements are the minerals bastnäsite ( RCO 3 F , where R is a mixture of rare-earth elements), monazite ( XPO 4 , where X is a mixture of rare-earth elements and sometimes thorium), and loparite ( (Ce,Na,Ca)(Ti,Nb)O 3 ), and the lateritic ion-adsorption clays . Despite their high relative abundance, rare-earth minerals are more difficult to mine and extract than equivalent sources of transition metals (due in part to their similar chemical properties), making
740-609: A CO 2 -rich primary magma, by fractional crystallization of an alkaline primary magma, or by separation of a CO 2 -rich immiscible liquid from. These liquids are most commonly forming in association with very deep Precambrian cratons , like the ones found in Africa and the Canadian Shield. Ferrocarbonatites are the most common type of carbonatite to be enriched in REE, and are often emplaced as late-stage, brecciated pipes at
888-621: A battery rather than to operate the radio directly. Flashlights may be driven by a dynamo directly. For transportation, uninterruptible power supply systems and laboratories, flywheel energy storage systems store energy in a spinning rotor for conversion to electric power when needed; such systems may be used to provide large pulses of power that would otherwise be objectionable on a common electrical grid. Ultracapacitors – capacitors of extremely high value – are also used; an electric screwdriver which charges in 90 seconds and will drive about half as many screws as
1036-399: A battery. For some types, the maximum charging rate will be limited by the speed at which active material can diffuse through a liquid electrolyte. High charging rates may produce excess gas in a battery, or may result in damaging side reactions that permanently lower the battery capacity. Very roughly, and with many exceptions and caveats, restoring a battery's full capacity in one hour or less
1184-571: A battery. To avoid damage from the cell reversal effect, it is necessary to access each cell separately: each cell is individually discharged by connecting a load clip across the terminals of each cell, thereby avoiding cell reversal. If a multi-cell battery is fully discharged, it will often be damaged due to the cell reversal effect mentioned above. It is possible however to fully discharge a battery without causing cell reversal—either by discharging each cell separately, or by allowing each cell's internal leakage to dissipate its charge over time. Even if
1332-466: A cell is brought to a fully discharged state without reversal, however, damage may occur over time simply due to remaining in the discharged state. An example of this is the sulfation that occurs in lead-acid batteries that are left sitting on a shelf for long periods. For this reason it is often recommended to charge a battery that is intended to remain in storage, and to maintain its charge level by periodically recharging it. Since damage may also occur if
1480-532: A component of magnets in hybrid car motors." The global demand for rare-earth elements (REEs) is expected to increase more than fivefold by 2030. The REE geochemical classification is usually done on the basis of their atomic weight . One of the most common classifications divides REE into 3 groups: light rare earths (LREE - from 57 La to 60 Nd), intermediate (MREE - from 62 Sm to 67 Ho) and heavy (HREE - from 68 Er to 71 Lu). REE usually appear as trivalent ions, except for Ce and Eu which can take
1628-443: A device using a rechargeable battery was introduced in 2007, and similar flashlights have been produced. In keeping with the concept of ultracapacitors, betavoltaic batteries may be utilized as a method of providing a trickle-charge to a secondary battery, greatly extending the life and energy capacity of the battery system being employed; this type of arrangement is often referred to as a "hybrid betavoltaic power source" by those in
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#17327796252051776-428: A discharged cell in this way causes undesirable and irreversible chemical reactions to occur, resulting in permanent damage to the cell. Cell reversal can occur under a number of circumstances, the two most common being: In the latter case, the problem occurs due to the different cells in a battery having slightly different capacities. When one cell reaches discharge level ahead of the rest, the remaining cells will force
1924-665: A few percent of yttrium). Uranium ores from Ontario have occasionally yielded yttrium as a byproduct. Well-known minerals containing cerium, and other LREE, include bastnäsite , monazite , allanite , loparite , ancylite , parisite , lanthanite , chevkinite, cerite , stillwellite , britholite, fluocerite , and cerianite. Monazite (marine sands from Brazil , India , or Australia ; rock from South Africa ), bastnäsite (from Mountain Pass rare earth mine , or several localities in China), and loparite ( Kola Peninsula , Russia ) have been
2072-404: A freshly charged AA NiMH cell in good condition is about 1.4 volts. Complete discharge of multi-cell packs can cause reverse polarity in one or more cells, which can permanently damage them. This situation can occur in the common arrangement of four AA cells in series, where one cell completely discharges before the others due to small differences in capacity among the cells. When this happens,
2220-451: A fully charged state. Some chargers do this after the charge cycle, to offset natural self-discharge. A similar approach is suggested by Energizer, which indicates that self-catalysis can recombine gas formed at the electrodes for charge rates up to C/10. This leads to cell heating. The company recommends C /30 or C /40 for indefinite applications where long life is important. This is the approach taken in emergency lighting applications, where
2368-468: A higher specific energy than nickel–metal hydride batteries, but they were originally significantly more expensive. The cost of lithium batteries fell drastically during the 2010s and many small consumer devices now have non-consumer-replaceable lithium batteries as a result. Lithium batteries produce a higher voltage (3.2–3.7 V nominal), and are thus not a drop-in replacement for AA (alkaline or NiMh) batteries without circuitry to reduce voltage. Although
2516-467: A hybrid lead–acid battery and ultracapacitor invented by Australia's national science organisation CSIRO , exhibits tens of thousands of partial state of charge cycles and has outperformed traditional lead-acid, lithium, and NiMH-based cells when compared in testing in this mode against variability management power profiles. UltraBattery has kW and MW-scale installations in place in Australia, Japan, and
2664-537: A hydrogen-absorbing alloy for the negative electrode instead of cadmium . The lithium-ion battery was introduced in the market in 1991, is the choice in most consumer electronics, having the best energy density and a very slow loss of charge when not in use. It does have drawbacks too, particularly the risk of unexpected ignition from the heat generated by the battery. Such incidents are rare and according to experts, they can be minimized "via appropriate design, installation, procedures and layers of safeguards" so
2812-551: A long and stable lifetime. The effective number of cycles is above 5000 and the battery is not damaged by deep discharge. The energy density is rather low, somewhat lower than lead–acid. A rechargeable battery is only one of several types of rechargeable energy storage systems. Several alternatives to rechargeable batteries exist or are under development. For uses such as portable radios , rechargeable batteries may be replaced by clockwork mechanisms which are wound up by hand, driving dynamos , although this system may be used to charge
2960-473: A low rate, typically taking 14 hours or more to reach a full charge. Rapid chargers can typically charge cells in two to five hours, depending on the model, with the fastest taking as little as fifteen minutes. Fast chargers must have multiple ways of detecting when a cell reaches full charge (change in terminal voltage, temperature, etc.) to stop charging before harmful overcharging or overheating occurs. The fastest chargers often incorporate cooling fans to keep
3108-544: A maximum number of 25 was estimated. The use of X-ray spectra (obtained by X-ray crystallography ) by Henry Gwyn Jeffreys Moseley made it possible to assign atomic numbers to the elements. Moseley found that the exact number of lanthanides had to be 15, but that element 61 had not yet been discovered. (This is promethium, a radioactive element whose most stable isotope has a half-life of just 18 years.) Using these facts about atomic numbers from X-ray crystallography, Moseley also showed that hafnium (element 72) would not be
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#17327796252053256-432: A melt phase if one is present. REE are chemically very similar and have always been difficult to separate, but the gradual decrease in ionic radius from light REE (LREE) to heavy REE (HREE), called the lanthanide contraction , can produce a broad separation between light and heavy REE. The larger ionic radii of LREE make them generally more incompatible than HREE in rock-forming minerals, and will partition more strongly into
3404-404: A melt phase, while HREE may prefer to remain in the crystalline residue, particularly if it contains HREE-compatible minerals like garnet . The result is that all magma formed from partial melting will always have greater concentrations of LREE than HREE, and individual minerals may be dominated by either HREE or LREE, depending on which range of ionic radii best fits the crystal lattice. Among
3552-888: A much lower total cost of ownership and environmental impact , as they can be recharged inexpensively many times before they need replacing. Some rechargeable battery types are available in the same sizes and voltages as disposable types, and can be used interchangeably with them. Billions of dollars in research are being invested around the world for improving batteries as industry focuses on building better batteries. Devices which use rechargeable batteries include automobile starters , portable consumer devices, light vehicles (such as motorized wheelchairs , golf carts , electric bicycles , and electric forklifts ), road vehicles (cars, vans, trucks, motorbikes), trains, small airplanes, tools, uninterruptible power supplies , and battery storage power stations . Emerging applications in hybrid internal combustion-battery and electric vehicles drive
3700-533: A popular improvement of the NiMH battery and founded Ovonic Battery Company in 1982. General Motors purchased Ovonics' patent in 1994. By the late 1990s, NiMH batteries were being used successfully in many fully electric vehicles, such as the General Motors EV1 and Dodge Caravan EPIC minivan. This generation of electric cars, although successful, was abruptly pulled off the market. In October 2000,
3848-538: A protection layer), alkaline treatment of negative electrode (causing reduction of leach-out of Mn and Al), addition of LiOH and NaOH into electrolyte (causing reduction in electrolyte corrosion capabilities), and addition of Al 2 (SO 4 ) 3 into electrolyte (causing reduction in MH alloy corrosion). Most of these improvements have no or negligible effect on cost; some increase cost modestly. NiMH cells are often used in digital cameras and other high-drain devices, where over
3996-456: A rare-earth element. Moseley was killed in World War I in 1915, years before hafnium was discovered. Hence, the claim of Georges Urbain that he had discovered element 72 was untrue. Hafnium is an element that lies in the periodic table immediately below zirconium , and hafnium and zirconium have very similar chemical and physical properties. During the 1940s, Frank Spedding and others in
4144-632: A rate of around 1× C (full discharge in 1 hour), it does not differ significantly from the nominal capacity. NiMH batteries nominally operate at 1.2 V per cell, somewhat lower than conventional 1.5 V cells, but can operate many devices designed for that voltage . NiMH batteries were frequently used in prior-generation electric and hybrid-electric vehicles; as of 2020 they have been superseded almost entirely by lithium-ion batteries in all-electric and plug-in hybrid vehicles, but they remain in use in some hybrid vehicles (2020 Toyota Highlander, for example). Prior all-electric plug-in vehicles included
4292-486: A regulated current source that tapers as the battery reaches fully charged voltage. Charging a battery incorrectly can damage a battery; in extreme cases, batteries can overheat, catch fire, or explosively vent their contents. Battery charging and discharging rates are often discussed by referencing a "C" rate of current. The C rate is that which would theoretically fully charge or discharge the battery in one hour. For example, trickle charging might be performed at C/20 (or
4440-483: A resistive voltage drop that is greater than the cell's forward emf . This results in the reversal of the cell's polarity while the current is flowing. The higher the required discharge rate of a battery, the better matched the cells should be, both in the type of cell and state of charge, in order to reduce the chances of cell reversal. In some situations, such as when correcting NiCd batteries that have been previously overcharged, it may be desirable to fully discharge
4588-404: A separate group of rare-earth elements (the terbium group), or europium was included in the cerium group, and gadolinium and terbium were included in the yttrium group. In the latter case, the f-block elements are split into half: the first half (La–Eu) form the cerium group, and the second half (Gd–Yb) together with group 3 (Sc, Y, Lu) form the yttrium group. The reason for this division arose from
Nickel–metal hydride battery - Misplaced Pages Continue
4736-494: A set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals . Compounds containing rare earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes. Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electrical and magnetic properties . The term 'rare-earth'
4884-420: A similar effect. In sedimentary rocks, rare-earth elements in clastic sediments are a representation of provenance. The rare-earth element concentrations are not typically affected by sea and river waters, as rare-earth elements are insoluble and thus have very low concentrations in these fluids. As a result, when sediment is transported, rare-earth element concentrations are unaffected by the fluid and instead
5032-503: A single lithium cell will typically provide ideal power to replace 3 NiMH cells, the form factor means that the device still needs modification. NiMH batteries can easily be made smaller and lighter than lead-acid batteries and have completely replaced them in small devices. However, lead-acid batteries can deliver huge current at low cost, making lead-acid batteries more suitable for starter motors in combustion vehicles. As of 2005, nickel–metal hydride batteries constituted three percent of
5180-452: A sulfonated polyolefin separator, an improvement over the hydrophilic polyolefin based on ethylene vinyl alcohol . Low-self-discharge cells have somewhat lower capacity than otherwise equivalent NiMH cells because of the larger volume of the separator. The highest-capacity low-self-discharge AA cells have 2500 mAh capacity, compared to 2700 mAh for high-capacity AA NiMH cells. Common methods to improve self-discharge include: use of
5328-800: A sulfonated separator (causing removal of N-containing compounds), use of an acrylic acid grafted PP separator (causing reduction in Al- and Mn-debris formation in separator), removal of Co and Mn in A 2 B 7 MH alloy, (causing reduction in debris formation in separator), increase of the amount of electrolyte (causing reduction in the hydrogen diffusion in electrolyte), removal of Cu-containing components (causing reduction in micro-short), PTFE coating on positive electrode (causing suppression of reaction between NiOOH and H 2 ), CMC solution dipping (causing suppression of oxygen evolution), micro-encapsulation of Cu on MH alloy (causing decrease in H 2 released from MH alloy), Ni–B alloy coating on MH alloy (causing formation of
5476-540: A terminal voltage that does not decline rapidly until nearly exhausted. This terminal voltage drop complicates the design of power electronics for use with ultracapacitors. However, there are potential benefits in cycle efficiency, lifetime, and weight compared with rechargeable systems. China started using ultracapacitors on two commercial bus routes in 2006; one of them is route 11 in Shanghai . Flow batteries , used for specialized applications, are recharged by replacing
5624-976: A type of energy accumulator ), is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or primary battery , which is supplied fully charged and discarded after use. It is composed of one or more electrochemical cells . The term "accumulator" is used as it accumulates and stores energy through a reversible electrochemical reaction . Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network . Several different combinations of electrode materials and electrolytes are used, including lead–acid , zinc–air , nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lithium-ion (Li-ion), lithium iron phosphate (LiFePO4), and lithium-ion polymer (Li-ion polymer). Rechargeable batteries typically initially cost more than disposable batteries but have
5772-462: A valence of 3 and form sesquioxides (cerium forms CeO 2 ). Five different crystal structures are known, depending on the element and the temperature. The X-phase and the H-phase are only stable above 2000 K. At lower temperatures, there are the hexagonal A-phase, the monoclinic B-phase, and the cubic C-phase, which is the stable form at room temperature for most of the elements. The C-phase
5920-460: Is 5–20% on the first day and stabilizes around 0.5–4% per day at room temperature . But at 45 °C (113 °F) it is approximately three times as high. The low–self-discharge nickel–metal hydride battery ( LSD NiMH ) has a significantly lower rate of self-discharge. The innovation was introduced in 2005 by Sanyo , branded Eneloop . By using improvements to electrode separator, positive electrode, and other components, manufacturers claim
6068-472: Is AB 5 , where A is a rare-earth mixture of lanthanum , cerium , neodymium , praseodymium , and B is nickel , cobalt , manganese , or aluminium . Some cells use higher-capacity negative electrode materials based on AB 2 compounds, where A is titanium or vanadium , and B is zirconium or nickel, modified with chromium , cobalt, iron , or manganese . NiMH cells have an alkaline electrolyte , usually potassium hydroxide . The positive electrode
Nickel–metal hydride battery - Misplaced Pages Continue
6216-604: Is a misnomer because they are not actually scarce, although historically it took a long time to isolate these elements. These metals tarnish slowly in air at room temperature and react slowly with cold water to form hydroxides, liberating hydrogen. They react with steam to form oxides and ignite spontaneously at a temperature of 400 °C (752 °F). These elements and their compounds have no biological function other than in several specialized enzymes, such as in lanthanide-dependent methanol dehydrogenases in bacteria. The water-soluble compounds are mildly to moderately toxic, but
6364-416: Is a refinement of lithium ion technology by Excellatron. The developers claim a large increase in recharge cycles to around 40,000 and higher charge and discharge rates, at least 5 C charge rate. Sustained 60 C discharge and 1000 C peak discharge rate and a significant increase in specific energy , and energy density. lithium iron phosphate batteries are used in some applications. UltraBattery ,
6512-400: Is already in place for the product. The potassium-ion battery delivers around a million cycles, due to the extraordinary electrochemical stability of potassium insertion/extraction materials such as Prussian blue . The sodium-ion battery is meant for stationary storage and competes with lead–acid batteries. It aims at a low total cost of ownership per kWh of storage. This is achieved by
6660-465: Is called the bixbyite structure, as it occurs in a mineral of that name ( (Mn,Fe) 2 O 3 ). As seen in the chart, rare-earth elements are found on Earth at similar concentrations to many common transition metals. The most abundant rare-earth element is cerium , which is actually the 25th most abundant element in Earth's crust , having 68 parts per million (about as common as copper). The exception
6808-413: Is considered fast charging. A battery charger system will include more complex control-circuit- and charging strategies for fast charging, than for a charger designed for slower recharging. The active components in a secondary cell are the chemicals that make up the positive and negative active materials, and the electrolyte . The positive and negative electrodes are made up of different materials, with
6956-470: Is employed, when the cells vary in temperature. This is because capacity significantly declines as the cells are cooled. This results in a lower voltage under load of the colder cells. Historically, NiMH cells have had a somewhat higher self-discharge rate (equivalent to internal leakage) than NiCd cells. The self-discharge rate varies greatly with temperature, where lower storage temperature leads to slower discharge and longer battery life. The self-discharge
7104-554: Is high, weathering forms a thick argillized regolith, this process is called supergene enrichment and produces laterite deposits; heavy rare-earth elements are incorporated into the residual clay by absorption. This kind of deposit is only mined for REE in Southern China, where the majority of global heavy rare-earth element production occurs. REE-laterites do form elsewhere, including over the carbonatite at Mount Weld in Australia. REE may also be extracted from placer deposits if
7252-449: Is nickel hydroxide, and the negative electrode is hydrogen in the form of an interstitial metal hydride. Hydrophilic polyolefin nonwovens are used for separation. When fast-charging, it is advisable to charge the NiMH cells with a smart battery charger to avoid overcharging , which can damage cells. The simplest of the safe charging methods is with a fixed low current, with or without a timer. Most manufacturers claim that overcharging
7400-427: Is no longer available to participate in the next discharge cycle. Sealed batteries may lose moisture from their liquid electrolyte, especially if overcharged or operated at high temperature. This reduces the cycling life. Recharging time is an important parameter to the user of a product powered by rechargeable batteries. Even if the charging power supply provides enough power to operate the device as well as recharge
7548-445: Is possible to observe the serial trend of the REE by reporting their normalized concentrations against the atomic number. The trends that are observed in "spider" diagrams are typically referred to as "patterns", which may be diagnostic of petrological processes that have affected the material of interest. According to the general shape of the patterns or thanks to the presence (or absence) of so-called "anomalies", information regarding
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#17327796252057696-443: Is provided here. Some of the rare-earth elements are named after the scientists who discovered them, or elucidated their elemental properties, and some after the geographical locations where discovered. A mnemonic for the names of the sixth-row elements in order is "Lately college parties never produce sexy European girls that drink heavily even though you look". Rare earths were mainly discovered as components of minerals. Ytterbium
7844-413: Is safe at very low currents, below 0.1 C ( C /10) (where C is the current equivalent to the capacity of the battery divided by one hour). The Panasonic NiMH charging manual warns that overcharging for long enough can damage a battery and suggests limiting the total charging time to 10–20 hours. Duracell further suggests that a trickle charge at C /300 can be used for batteries that must be kept in
7992-438: Is spread thin across trace impurities, so to obtain rare earths at usable purity requires processing enormous amounts of raw ore at great expense, thus the name "rare" earths. Because of their geochemical properties, rare-earth elements are typically dispersed and not often found concentrated in rare-earth minerals . Consequently, economically exploitable ore deposits are sparse. The first rare-earth mineral discovered (1787)
8140-443: Is synthetically produced in nuclear reactors. Due to their chemical similarity, the concentrations of rare earths in rocks are only slowly changed by geochemical processes, making their proportions useful for geochronology and dating fossils. Rare-earth elements occur in nature in combination with phosphate ( monazite ), carbonate - fluoride ( bastnäsite ), and oxygen anions. In their oxides, most rare-earth elements only have
8288-517: Is the highly unstable and radioactive promethium "rare earth" is quite scarce. The longest-lived isotope of promethium has a half-life of 17.7 years, so the element exists in nature in only negligible amounts (approximately 572 g in the entire Earth's crust). Promethium is one of the two elements that do not have stable (non-radioactive) isotopes and are followed by (i.e. with higher atomic number) stable elements (the other being technetium ). The rare-earth elements are often found together. During
8436-400: Is to monitor the change of voltage with time. When the battery is fully charged, the voltage across its terminals drops slightly. The charger can detect this and stop charging. This method is often used with nickel–cadmium cells, which display a large voltage drop at full charge. However, the voltage drop is much less pronounced for NiMH and can be non-existent at low charge rates, which can make
8584-533: The General Motors EV1 , first-generation Toyota RAV4 EV , Honda EV Plus , Ford Ranger EV and Vectrix scooter. Every first generation hybrid vehicle used NIMH batteries, most notably the Toyota Prius and Honda Insight , as well as later models including the Ford Escape Hybrid , Chevrolet Malibu Hybrid and Honda Civic Hybrid also use them. Stanford R. Ovshinsky invented and patented
8732-563: The Oddo–Harkins rule : even-numbered REE at abundances of about 5% each, and odd-numbered REE at abundances of about 1% each. Similar compositions are found in xenotime or gadolinite. Well-known minerals containing yttrium, and other HREE, include gadolinite, xenotime, samarskite , euxenite , fergusonite , yttrotantalite, yttrotungstite, yttrofluorite (a variety of fluorite ), thalenite, and yttrialite . Small amounts occur in zircon , which derives its typical yellow fluorescence from some of
8880-413: The memory effect ) from repeated partial discharge can occur, but is reversible with a few full discharge/charge cycles. A fully charged cell supplies an average 1.25 V/cell during discharge, declining to about 1.0–1.1 V/cell (further discharge may cause permanent damage in the case of multi-cell packs, due to polarity reversal of the weakest cell). Under a light load (0.5 amperes), the starting voltage of
9028-486: The upper mantle (200 to 600 km depth). This melt becomes enriched in incompatible elements, like the rare-earth elements, by leaching them out of the crystalline residue. The resultant magma rises as a diapir , or diatreme , along pre-existing fractures, and can be emplaced deep in the crust , or erupted at the surface. Typical REE enriched deposits types forming in rift settings are carbonatites, and A- and M-Type granitoids. Near subduction zones, partial melting of
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#17327796252059176-428: The "heavy" group from 6.965 (ytterbium) to 9.32 (thulium), as well as including yttrium at 4.47. Europium has a density of 5.24. Rare-earth elements, except scandium , are heavier than iron and thus are produced by supernova nucleosynthesis or by the s-process in asymptotic giant branch stars. In nature, spontaneous fission of uranium-238 produces trace amounts of radioactive promethium , but most promethium
9324-568: The 4 f orbital which acts against the electrons of the 6 s and 5 d orbitals. The lanthanide contraction has a direct effect on the geochemistry of the lanthanides, which show a different behaviour depending on the systems and processes in which they are involved. The effect of the lanthanide contraction can be observed in the REE behaviour both in a CHARAC-type geochemical system (CHArge-and-RAdius-Controlled ) where elements with similar charge and radius should show coherent geochemical behaviour, and in non-CHARAC systems, such as aqueous solutions, where
9472-506: The LREE. This has economic consequences: large ore bodies of LREE are known around the world and are being exploited. Ore bodies for HREE are more rare, smaller, and less concentrated. Most of the current supply of HREE originates in the "ion-absorption clay" ores of Southern China. Some versions provide concentrates containing about 65% yttrium oxide, with the HREE being present in ratios reflecting
9620-572: The Ti–Ni alloy structure and composition and patented its innovations. In 2008, more than two million hybrid cars worldwide were manufactured with NiMH batteries. In the European Union due to its Battery Directive , nickel–metal hydride batteries replaced Ni–Cd batteries for portable consumer use. About 22% of portable rechargeable batteries sold in Japan in 2010 were NiMH. In Switzerland in 2009,
9768-479: The U.S. It has also been subjected to extensive testing in hybrid electric vehicles and has been shown to last more than 100,000 vehicle miles in on-road commercial testing in a courier vehicle. The technology is claimed to have a lifetime of 7 to 10 times that of conventional lead-acid batteries in high rate partial state-of-charge use, with safety and environmental benefits claimed over competitors like lithium-ion. Its manufacturer suggests an almost 100% recycling rate
9916-530: The United States (during the Manhattan Project ) developed chemical ion-exchange procedures for separating and purifying rare-earth elements. This method was first applied to the actinides for separating plutonium-239 and neptunium from uranium , thorium , actinium , and the other actinides in the materials produced in nuclear reactors . Plutonium-239 was very desirable because it is
10064-414: The United States, and Japan. The patents transferred to Daimler-Benz. Interest grew in the 1970s with the commercialisation of the nickel–hydrogen battery for satellite applications. Hydride technology promised an alternative, less bulky way to store the hydrogen. Research carried out by Philips Laboratories and France's CNRS developed new high-energy hybrid alloys incorporating rare-earth metals for
10212-449: The accompanying HREE. The zirconium mineral eudialyte , such as is found in southern Greenland , contains small but potentially useful amounts of yttrium. Of the above yttrium minerals, most played a part in providing research quantities of lanthanides during the discovery days. Xenotime is occasionally recovered as a byproduct of heavy-sand processing, but is not as abundant as the similarly recovered monazite (which typically contains
10360-500: The anhydrous rare-earth phosphates, it is the tetragonal mineral xenotime that incorporates yttrium and the HREE, whereas the monoclinic monazite phase incorporates cerium and the LREE preferentially. The smaller size of the HREE allows greater solid solubility in the rock-forming minerals that make up Earth's mantle, and thus yttrium and the HREE show less enrichment in Earth's crust relative to chondritic abundance than does cerium and
10508-428: The approach unreliable. Another option is to monitor the change of voltage with respect to time and stop when this becomes zero, but this risks premature cutoffs. With this method, a much higher charging rate can be used than with a trickle charge, up to 1 C . At this charge rate, Panasonic recommends to terminate charging when the voltage drops 5–10 mV per cell from the peak voltage. Since this method measures
10656-527: The battery is not constant during charging and discharging. Some types have relatively constant voltage during discharge over much of their capacity. Non-rechargeable alkaline and zinc–carbon cells output 1.5 V when new, but this voltage drops with use. Most NiMH AA and AAA cells are rated at 1.2 V, but have a flatter discharge curve than alkalines and can usually be used in equipment designed to use alkaline batteries . Battery manufacturers' technical notes often refer to voltage per cell (VPC) for
10804-404: The battery is overcharged, the optimal level of charge during storage is typically around 30% to 70%. Depth of discharge (DOD) is normally stated as a percentage of the nominal ampere-hour capacity; 0% DOD means no discharge. As the usable capacity of a battery system depends on the rate of discharge and the allowable voltage at the end of discharge, the depth of discharge must be qualified to show
10952-454: The battery market. NiMH batteries have replaced NiCd for many roles, notably small rechargeable batteries. NiMH batteries are commonly available in AA ( penlight -size) batteries. These have nominal charge capacities ( C ) of 1.1–2.8 Ah at 1.2 V, measured at the rate that discharges the cell in 5 hours. Useful discharge capacity is a decreasing function of the discharge rate, but up to
11100-457: The battery, the device is attached to an external power supply during the charging time. For electric vehicles used industrially, charging during off-shifts may be acceptable. For highway electric vehicles, rapid charging is necessary for charging in a reasonable time. A rechargeable battery cannot be recharged at an arbitrarily high rate. The internal resistance of the battery will produce heat, and excessive temperature rise will damage or destroy
11248-639: The better), and on its physical size and charge capacity. Separators keep the two electrodes apart to slow electrical discharge while allowing the transport of ionic charge carriers that close the circuit during the passage of current . High-quality separators are critical for battery performance. The self-discharge rate depends upon separator thickness; thicker separators reduce self-discharge, but also reduce capacity as they leave less space for active components, and thin separators lead to higher self-discharge. Some batteries may have overcome this tradeoff by using more precisely manufactured thin separators, and
11396-410: The cell reaches full charge, most of the charging energy is converted to heat. This increases the rate of change of battery temperature, which can be detected by a sensor such as a thermistor . Both Panasonic and Duracell suggest a maximal rate of temperature increase of 1 °C per minute. Using a temperature sensor allows an absolute temperature cutoff, which Duracell suggests at 60 °C. With both
11544-404: The cells from overheating. Battery packs intended for rapid charging may include a temperature sensor that the charger uses to protect the pack; the sensor will have one or more additional electrical contacts. Different battery chemistries require different charging schemes. For example, some battery types can be safely recharged from a constant voltage source. Other types need to be charged with
11692-422: The cells retain 70–85% of their capacity when stored for one year at 20 °C (68 °F), compared to about half for normal NiMH batteries. They are otherwise similar to standard NiMH batteries, and can be charged in standard NiMH chargers. These cells are marketed as "hybrid", "ready-to-use" or "pre-charged" rechargeables. Retention of charge depends in large part on the battery's leakage resistance (the higher
11840-606: The charging process. A method for very rapid charging called in-cell charge control involves an internal pressure switch in the cell, which disconnects the charging current in the event of overpressure. One inherent risk with NiMH chemistry is that overcharging causes hydrogen gas to form, potentially rupturing the cell. Therefore, cells have a vent to release the gas in the event of serious overcharging. NiMH batteries are made of environmentally friendly materials. The batteries contain only mildly toxic substances and are recyclable. Voltage depression (often mistakenly attributed to
11988-871: The core of igneous complexes; they consist of fine-grained calcite and hematite, sometimes with significant concentrations of ankerite and minor concentrations of siderite. Large carbonatite deposits enriched in rare-earth elements include Mount Weld in Australia, Thor Lake in Canada, Zandkopsdrift in South Africa, and Mountain Pass in the USA. Peralkaline granites (A-Type granitoids) have very high concentrations of alkaline elements and very low concentrations of phosphorus; they are deposited at moderate depths in extensional zones, often as igneous ring complexes, or as pipes, massive bodies, and lenses. These fluids have very low viscosities and high element mobility, which allows for
12136-408: The crude yttria and found the same substances that Mosander obtained, but Berlin named (1860) the substance giving pink salts erbium , and Delafontaine named the substance with the yellow peroxide terbium . This confusion led to several false claims of new elements, such as the mosandrium of J. Lawrence Smith , or the philippium and decipium of Delafontaine. Due to the difficulty in separating
12284-740: The crystallization of large grains, despite a relatively short crystallization time upon emplacement; their large grain size is why these deposits are commonly referred to as pegmatites. Economically viable pegmatites are divided into Lithium-Cesium-Tantalum (LCT) and Niobium-Yttrium-Fluorine (NYF) types; NYF types are enriched in rare-earth minerals. Examples of rare-earth pegmatite deposits include Strange Lake in Canada and Khaladean-Buregtey in Mongolia. Nepheline syenite (M-Type granitoids) deposits are 90% feldspar and feldspathoid minerals. They are deposited in small, circular massifs and contain high concentrations of rare-earth-bearing accessory minerals . For
12432-414: The current through the discharged cell. Many battery-operated devices have a low-voltage cutoff that prevents deep discharges from occurring that might cause cell reversal. A smart battery has voltage monitoring circuitry built inside. Cell reversal can occur to a weakly charged cell even before it is fully discharged. If the battery drain current is high enough, the cell's internal resistance can create
12580-660: The day to be used at night). Load-leveling reduces the maximum power which a plant must be able to generate, reducing capital cost and the need for peaking power plants . According to a report from Research and Markets, the analysts forecast the global rechargeable battery market to grow at a CAGR of 8.32% during the period 2018–2022. Small rechargeable batteries can power portable electronic devices , power tools, appliances, and so on. Heavy-duty batteries power electric vehicles , ranging from scooters to locomotives and ships . They are used in distributed electricity generation and in stand-alone power systems . During charging,
12728-497: The design remains essentially the same as in older NiCd units, except for an increase in the trickle-charging resistor value. Panasonic's handbook recommends that NiMH batteries on standby be charged by a lower duty cycle approach, where a pulse of a higher current is used whenever the battery's voltage drops below 1.3 V. This can extend battery life and use less energy. To prevent cell damage, fast chargers must terminate their charge cycle before overcharging occurs. One method
12876-413: The difference in solubility of rare-earth double sulfates with sodium and potassium. The sodium double sulfates of the cerium group are poorly soluble, those of the terbium group slightly, and those of the yttrium group are very soluble. Sometimes, the yttrium group was further split into the erbium group (dysprosium, holmium, erbium, and thulium) and the ytterbium group (ytterbium and lutetium), but today
13024-755: The duration of single-charge use they outperform primary (such as alkaline) batteries. NiMH cells are advantageous for high-current-drain applications compared to alkaline batteries, largely due to their lower internal resistance. Typical alkaline AA-size batteries, which offer approximately 2.6 Ah capacity at low current demand (25 mA), provide only 1.3 Ah capacity with a 500 mA load. Digital cameras with LCDs and flashlights can draw over 1 A, quickly depleting them. NiMH cells can deliver these current levels without similar loss of capacity. Devices that were designed to operate using primary alkaline chemistry (or zinc-carbon/chloride) cells may not function with NiMH cells. However, most devices compensate for
13172-529: The electrolyte liquid. A flow battery can be considered to be a type of rechargeable fuel cell . Rechargeable battery research includes development of new electrochemical systems as well as improving the life span and capacity of current types. Rare-earth element The rare-earth elements ( REE ), also called the rare-earth metals or rare earths , and sometimes the lanthanides or lanthanoids (although scandium and yttrium , which do not belong to this series, are usually included as rare earths), are
13320-409: The electron structure is also an important parameter to consider as the lanthanide contraction affects the ionic potential . A direct consequence is that, during the formation of coordination bonds, the REE behaviour gradually changes along the series. Furthermore, the lanthanide contraction causes the ionic radius of Ho (0.901 Å) to be almost identical to that of Y (0.9 Å), justifying the inclusion of
13468-651: The element showing the anomaly and the predictable one based on the average of the normalized concentrations of the two elements in the previous and next position in the series, according to the equation: where [ REE i ] n {\displaystyle [{\text{REE}}_{i}]_{n}} is the normalized concentration of the element whose anomaly has to be calculated, [ REE i − 1 ] n {\displaystyle [{\text{REE}}_{i-1}]_{n}} and [ REE i + 1 ] n {\displaystyle [{\text{REE}}_{i+1}]_{n}}
13616-415: The equivalent statistic was approximately 60%. This percentage has fallen over time due to the increase in manufacture of lithium-ion batteries: in 2000, almost half of all portable rechargeable batteries sold in Japan were NiMH. In 2015 BASF produced a modified microstructure that helped make NiMH batteries more durable, in turn allowing changes to the cell design that saved considerable weight, allowing
13764-417: The existence of an unknown element. The fractional crystallization of the oxides then yielded europium in 1901. In 1839 the third source for rare earths became available. This is a mineral similar to gadolinite called uranotantalum (now called " samarskite ") an oxide of a mixture of elements such as yttrium, ytterbium, iron, uranium, thorium, calcium, niobium, and tantalum. This mineral from Miass in
13912-511: The following observations apply: anomalies in europium are dominated by the crystallization of feldspars . Hornblende , controls the enrichment of MREE compared to LREE and HREE. Depletion of LREE relative to HREE may be due to the crystallization of olivine , orthopyroxene , and clinopyroxene . On the other hand, the depletion of HREE relative to LREE may be due to the presence of garnet , as garnet preferentially incorporates HREE into its crystal structure. The presence of zircon may also cause
14060-433: The form of Ce and Eu depending on the redox conditions of the system. Consequentially, REE are characterized by a substantial identity in their chemical reactivity, which results in a serial behaviour during geochemical processes rather than being characteristic of a single element of the series. Sc, Y, and Lu can be electronically distinguished from the other rare earths because they do not have f valence electrons, whereas
14208-566: The fractionation of trace elements (including rare-earth elements) into the liquid phase (the melt/magma) into the solid phase (the mineral). If an element preferentially remains in the solid phase it is termed 'compatible', and if it preferentially partitions into the melt phase it is described as 'incompatible'. Each element has a different partition coefficient, and therefore fractionates into solid and liquid phases distinctly. These concepts are also applicable to metamorphic and sedimentary petrology. In igneous rocks, particularly in felsic melts,
14356-581: The gadolinite but failed to recognize other elements in the ore. After this discovery in 1794, a mineral from Bastnäs near Riddarhyttan , Sweden, which was believed to be an iron – tungsten mineral, was re-examined by Jöns Jacob Berzelius and Wilhelm Hisinger . In 1803 they obtained a white oxide and called it ceria . Martin Heinrich Klaproth independently discovered the same oxide and called it ochroia . It took another 30 years for researchers to determine that other elements were contained in
14504-411: The good cells start to drive the discharged cell into reverse polarity (i.e. positive anode and negative cathode). Some cameras, GPS receivers and PDAs detect the safe end-of-discharge voltage of the series cells and perform an auto-shutdown, but devices such as flashlights and some toys do not. Irreversible damage from polarity reversal is a particular danger, even when a low voltage-threshold cutout
14652-448: The heavy rare-earth elements (HREE), and those that fall in between are typically referred to as the middle rare-earth elements (MREE). Commonly, rare-earth elements with atomic numbers 57 to 61 (lanthanum to promethium) are classified as light and those with atomic numbers 62 and greater are classified as heavy rare-earth elements. Increasing atomic numbers between light and heavy rare-earth elements and decreasing atomic radii throughout
14800-459: The individual cells that make up the battery. For example, to charge a 12 V lead-acid battery (containing 6 cells of 2 V each) at 2.3 VPC requires a voltage of 13.8 V across the battery's terminals. Subjecting a discharged cell to a current in the direction which tends to discharge it further to the point the positive and negative terminals switch polarity causes a condition called cell reversal . Generally, pushing current through
14948-417: The industry. Ultracapacitors are being developed for transportation, using a large capacitor to store energy instead of the rechargeable battery banks used in hybrid vehicles . One drawback of capacitors compared to batteries is that the terminal voltage drops rapidly; a capacitor that has 25% of its initial energy left in it will have one-half of its initial voltage. By contrast, battery systems tend to have
15096-502: The insoluble ones are not. All isotopes of promethium are radioactive, and it does not occur naturally in the earth's crust, except for a trace amount generated by spontaneous fission of uranium-238 . They are often found in minerals with thorium , and less commonly uranium . Though rare-earth elements are technically relatively plentiful in the entire Earth's crust ( cerium being the 25th-most-abundant element at 68 parts per million, more abundant than copper ), in practice this
15244-470: The latter among the REE. The application of rare-earth elements to geology is important to understanding the petrological processes of igneous , sedimentary and metamorphic rock formation. In geochemistry , rare-earth elements can be used to infer the petrological mechanisms that have affected a rock due to the subtle atomic size differences between the elements, which causes preferential fractionation of some rare earths relative to others depending on
15392-418: The logarithm to the base 10 of the value. Commonly, the rare-earth elements are normalized to chondritic meteorites , as these are believed to be the closest representation of unfractionated Solar System material. However, other normalizing standards can be applied depending on the purpose of the study. Normalization to a standard reference value, especially of a material believed to be unfractionated, allows
15540-522: The low cost, makes it attractive for use in motor vehicles to provide the high current required by automobile starter motors . The nickel–cadmium battery (NiCd) was invented by Waldemar Jungner of Sweden in 1899. It uses nickel oxide hydroxide and metallic cadmium as electrodes . Cadmium is a toxic element, and was banned for most uses by the European Union in 2004. Nickel–cadmium batteries have been almost completely superseded by nickel–metal hydride (NiMH) batteries. The nickel–iron battery (NiFe)
15688-472: The main grouping is between the cerium and the yttrium groups. Today, the rare-earth elements are classified as light or heavy rare-earth elements, rather than in cerium and yttrium groups. The classification of rare-earth elements is inconsistent between authors. The most common distinction between rare-earth elements is made by atomic numbers ; those with low atomic numbers are referred to as light rare-earth elements (LREE), those with high atomic numbers are
15836-522: The metals (and determining the separation is complete), the total number of false discoveries was dozens, with some putting the total number of discoveries at over a hundred. There were no further discoveries for 30 years, and the element didymium was listed in the periodic table of elements with a molecular mass of 138. In 1879, Delafontaine used the new physical process of optical flame spectroscopy and found several new spectral lines in didymia. Also in 1879, Paul Émile Lecoq de Boisbaudran isolated
15984-697: The most part, these deposits are small but important examples include Illimaussaq-Kvanefeld in Greenland, and Lovozera in Russia. Rare-earth elements can also be enriched in deposits by secondary alteration either by interactions with hydrothermal fluids or meteoric water or by erosion and transport of resistate REE-bearing minerals. Argillization of primary minerals enriches insoluble elements by leaching out silica and other soluble elements, recrystallizing feldspar into clay minerals such kaolinite, halloysite, and montmorillonite. In tropical regions where precipitation
16132-710: The negative electrode. However, these suffered from alloy instability in alkaline electrolyte and consequently insufficient cycle life. In 1987, Willems and Buschow demonstrated a successful battery based on this approach (using a mixture of La 0.8 Nd 0.2 Ni 2.5 Co 2.4 Si 0.1 ), which kept 84% of its charge capacity after 4000 charge-discharge cycles. More economically viable alloys using mischmetal instead of lanthanum were soon developed. Modern NiMH cells were based on this design. The first consumer-grade NiMH cells became commercially available in 1989. In 1998, Stanford Ovshinsky at Ovonic Battery Co. , which had been working on MH-NiOOH batteries since mid-1980, improved
16280-560: The new element samarium from the mineral samarskite . The samaria earth was further separated by Lecoq de Boisbaudran in 1886, and a similar result was obtained by Jean Charles Galissard de Marignac by direct isolation from samarskite. They named the element gadolinium after Johan Gadolin , and its oxide was named " gadolinia ". Further spectroscopic analysis between 1886 and 1901 of samaria, yttria, and samarskite by William Crookes , Lecoq de Boisbaudran and Eugène-Anatole Demarçay yielded several new spectral lines that indicated
16428-424: The normalized concentration, [ REE i ] sam {\displaystyle {[{\text{REE}}_{i}]_{\text{sam}}}} the analytical concentration of the element measured in the sample, and [ REE i ] ref {\displaystyle {[{\text{REE}}_{i}]_{\text{ref}}}} the concentration of the same element in the reference material. It
16576-427: The normalized concentrations of the respectively previous and next elements along the series. The rare-earth elements patterns observed in igneous rocks are primarily a function of the chemistry of the source where the rock came from, as well as the fractionation history the rock has undergone. Fractionation is in turn a function of the partition coefficients of each element. Partition coefficients are responsible for
16724-500: The number of charge cycles increases, until they are eventually considered to have reached the end of their useful life. Different battery systems have differing mechanisms for wearing out. For example, in lead-acid batteries, not all the active material is restored to the plates on each charge/discharge cycle; eventually enough material is lost that the battery capacity is reduced. In lithium-ion types, especially on deep discharge, some reactive lithium metal can be formed on charging, which
16872-432: The observed abundances to be compared to the initial abundances of the element. Normalization also removes the pronounced 'zig-zag' pattern caused by the differences in abundance between even and odd atomic numbers . Normalization is carried out by dividing the analytical concentrations of each element of the series by the concentration of the same element in a given standard, according to the equation: where n indicates
17020-414: The others do, but the chemical behaviour is almost the same. A distinguishing factor in the geochemical behaviour of the REE is linked to the so-called " lanthanide contraction " which represents a higher-than-expected decrease in the atomic/ionic radius of the elements along the series. This is determined by the variation of the shielding effect towards the nuclear charge due to the progressive filling of
17168-529: The patent was sold to Texaco , and a week later Texaco was acquired by Chevron . Chevron's Cobasys subsidiary provides these batteries only to large OEM orders. General Motors shut down production of the EV1 , citing lack of battery availability as a chief obstacle. Cobasys control of NiMH batteries created a patent encumbrance for large automotive NiMH batteries. Rechargeable battery A rechargeable battery , storage battery , or secondary cell (formally
17316-510: The positive active material is oxidized , releasing electrons , and the negative material is reduced , absorbing electrons. These electrons constitute the current flow in the external circuit . The electrolyte may serve as a simple buffer for internal ion flow between the electrodes , as in lithium-ion and nickel-cadmium cells, or it may be an active participant in the electrochemical reaction, as in lead–acid cells. The energy used to charge rechargeable batteries usually comes from
17464-467: The positive electrode is the cathode on discharge and the anode on charge, and vice versa for the negative electrode. The lead–acid battery , invented in 1859 by French physicist Gaston Planté , is the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, its ability to supply high surge currents means that the cells have a relatively large power-to-weight ratio . These features, along with
17612-532: The positive exhibiting a reduction potential and the negative having an oxidation potential. The sum of the potentials from these half-reactions is the standard cell potential or voltage . In primary cells the positive and negative electrodes are known as the cathode and anode , respectively. Although this convention is sometimes carried through to rechargeable systems—especially with lithium-ion cells, because of their origins in primary lithium cells—this practice can lead to confusion. In rechargeable cells
17760-446: The principal ores of cerium and the light lanthanides. Enriched deposits of rare-earth elements at the surface of the Earth, carbonatites and pegmatites , are related to alkaline plutonism , an uncommon kind of magmatism that occurs in tectonic settings where there is rifting or that are near subduction zones. In a rift setting, the alkaline magma is produced by very small degrees of partial melting (<1%) of garnet peridotite in
17908-440: The processes at work. The geochemical study of the REE is not carried out on absolute concentrations – as it is usually done with other chemical elements – but on normalized concentrations in order to observe their serial behaviour. In geochemistry, rare-earth elements are typically presented in normalized "spider" diagrams, in which concentration of rare-earth elements are normalized to a reference standard and are then expressed as
18056-483: The range of 150–260 Wh/kg, batteries based on lithium-sulfur are expected to achieve 450–500 Wh/kg, and can eliminate cobalt, nickel and manganese from the production process. Furthermore, while initially lithium-sulfur batteries suffered from stability problems, recent research has made advances in developing lithium-sulfur batteries that cycle as long as (or longer than) batteries based on conventional lithium-ion technologies. The thin-film battery (TFB)
18204-421: The rare-earth elements relatively expensive. Their industrial use was very limited until efficient separation techniques were developed, such as ion exchange , fractional crystallization, and liquid–liquid extraction during the late 1950s and early 1960s. Some ilmenite concentrates contain small amounts of scandium and other rare-earth elements, which could be analysed by X-ray fluorescence (XRF). Before
18352-461: The relationship between time and discharge rate is described by Peukert's law ; a lead-acid cell that can no longer sustain a usable terminal voltage at a high current may still have usable capacity, if discharged at a much lower rate. Data sheets for rechargeable cells often list the discharge capacity on 8-hour or 20-hour or other stated time; cells for uninterruptible power supply systems may be rated at 15-minute discharge. The terminal voltage of
18500-593: The risk is acceptable. Lithium-ion polymer batteries (LiPo) are light in weight, offer slightly higher energy density than Li-ion at slightly higher cost, and can be made in any shape. They are available but have not displaced Li-ion in the market. A primary use is for LiPo batteries is in powering remote-controlled cars, boats and airplanes. LiPo packs are readily available on the consumer market, in various configurations, up to 44.4 V, for powering certain R/C vehicles and helicopters or drones. Some test reports warn of
18648-595: The risk of fire when the batteries are not used in accordance with the instructions. Independent reviews of the technology discuss the risk of fire and explosion from lithium-ion batteries under certain conditions because they use liquid electrolytes. ‡ citations are needed for these parameters Several types of lithium–sulfur battery have been developed, and numerous research groups and organizations have demonstrated that batteries based on lithium sulfur can achieve superior energy density to other lithium technologies. Whereas lithium-ion batteries offer energy density in
18796-459: The same size, with significantly higher energy density , although only about half that of lithium-ion batteries . They are typically used as a substitute for similarly shaped non-rechargeable alkaline batteries , as they feature a slightly lower but generally compatible cell voltage and are less prone to leaking . Work on NiMH batteries began at the Battelle -Geneva Research Center following
18944-636: The seafloor, bit by bit, over tens of millions of years. One square patch of metal-rich mud 2.3 kilometers wide might contain enough rare earths to meet most of the global demand for a year, Japanese geologists report in Nature Geoscience ." "I believe that rare[-]earth resources undersea are much more promising than on-land resources," said Kato. "[C]oncentrations of rare earths were comparable to those found in clays mined in China. Some deposits contained twice as much heavy rare earths such as dysprosium,
19092-493: The sedimentary parent lithology contains REE-bearing, heavy resistate minerals. In 2011, Yasuhiro Kato, a geologist at the University of Tokyo who led a study of Pacific Ocean seabed mud, published results indicating the mud could hold rich concentrations of rare-earth minerals. The deposits, studied at 78 sites, came from "[h]ot plumes from hydrothermal vents pull[ing] these materials out of seawater and deposit[ing] them on
19240-419: The sequential accretion of the Earth, the dense rare-earth elements were incorporated into the deeper portions of the planet. Early differentiation of molten material largely incorporated the rare earths into mantle rocks. The high field strength and large ionic radii of rare earths make them incompatible with the crystal lattices of most rock-forming minerals, so REE will undergo strong partitioning into
19388-497: The series causes chemical variations. Europium is exempt of this classification as it has two valence states: Eu and Eu . Yttrium is grouped as heavy rare-earth element due to chemical similarities. The break between the two groups is sometimes put elsewhere, such as between elements 63 (europium) and 64 (gadolinium). The actual metallic densities of these two groups overlap, with the "light" group having densities from 6.145 (lanthanum) to 7.26 (promethium) or 7.52 (samarium) g/cc, and
19536-401: The southern Ural Mountains was documented by Gustav Rose . The Russian chemist R. Harmann proposed that a new element he called " ilmenium " should be present in this mineral, but later, Christian Wilhelm Blomstrand , Galissard de Marignac, and Heinrich Rose found only tantalum and niobium ( columbium ) in it. The exact number of rare-earth elements that existed was highly unclear, and
19684-492: The specific energy to reach 140 watt-hours per kilogram. The negative electrode reaction occurring in a NiMH cell is On the positive electrode, nickel oxyhydroxide, NiO(OH), is formed: The reactions proceed left to right during charge and the opposite during discharge. The metal M in the negative electrode of a NiMH cell is an intermetallic compound. Many different compounds have been developed for this application, but those in current use fall into two classes. The most common
19832-766: The subducting plate within the asthenosphere (80 to 200 km depth) produces a volatile-rich magma (high concentrations of CO 2 and water), with high concentrations of alkaline elements, and high element mobility that the rare earths are strongly partitioned into. This melt may also rise along pre-existing fractures, and be emplaced in the crust above the subducting slab or erupted at the surface. REE-enriched deposits forming from these melts are typically S-Type granitoids. Alkaline magmas enriched with rare-earth elements include carbonatites, peralkaline granites (pegmatites), and nepheline syenite . Carbonatites crystallize from CO 2 -rich fluids, which can be produced by partial melting of hydrous-carbonated lherzolite to produce
19980-399: The system under examination and the occurring geochemical processes can be obtained. The anomalies represent enrichment (positive anomalies) or depletion (negative anomalies) of specific elements along the series and are graphically recognizable as positive or negative "peaks" along the REE patterns. The anomalies can be numerically quantified as the ratio between the normalized concentration of
20128-596: The technology to reduce cost, weight, and size, and increase lifetime. Older rechargeable batteries self-discharge relatively rapidly and require charging before first use; some newer low self-discharge NiMH batteries hold their charge for many months, and are typically sold factory-charged to about 70% of their rated capacity. Battery storage power stations use rechargeable batteries for load-leveling (storing electric energy at times of low demand for use during peak periods) and for renewable energy uses (such as storing power generated from photovoltaic arrays during
20276-667: The technology's invention in 1967. It was based on sintered Ti 2 Ni+TiNi+x alloys and NiOOH electrodes. Development was sponsored over nearly two decades by Daimler-Benz and by Volkswagen AG within Deutsche Automobilgesellschaft, now a subsidiary of Daimler AG . The batteries' specific energy reached 50 W·h/kg (180 kJ/kg), specific power up to 1000 W/kg and a life of 500 charge cycles (at 100% depth of discharge ). Patent applications were filed in European countries (priority: Switzerland),
20424-479: The time that ion exchange methods and elution were available, the separation of the rare earths was primarily achieved by repeated precipitation or crystallization . In those days, the first separation was into two main groups, the cerium earths (lanthanum, cerium, praseodymium, neodymium, and samarium) and the yttrium earths (scandium, yttrium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). Europium, gadolinium, and terbium were either considered as
20572-484: The two ores ceria and yttria (the similarity of the rare-earth metals' chemical properties made their separation difficult). In 1839 Carl Gustav Mosander , an assistant of Berzelius, separated ceria by heating the nitrate and dissolving the product in nitric acid . He called the oxide of the soluble salt lanthana . It took him three more years to separate the lanthana further into didymia and pure lanthana. Didymia, although not further separable by Mosander's techniques,
20720-404: The voltage across the battery, a constant-current (rather than a constant-voltage) charging circuit is used. The temperature-change method is similar in principle to the Δ V method. Because the charging voltage is nearly constant, constant-current charging delivers energy at a near-constant rate. When the cell is not fully charged, most of this energy is converted to chemical energy. However, when
20868-483: The voltage drop of an alkaline battery as it discharges down to about 1 volt. Low internal resistance allows NiMH cells to deliver a nearly constant voltage until they are almost completely discharged. Thus battery-level indicators designed to read alkaline cells overstate the remaining charge when used with NiMH cells, as the voltage of alkaline cells decreases steadily during most of the discharge cycle. Lithium-ion batteries can deliver extremely high power and have
21016-582: The way it is to be measured. Due to variations during manufacture and aging, the DOD for complete discharge can change over time or number of charge cycles . Generally a rechargeable battery system will tolerate more charge/discharge cycles if the DOD is lower on each cycle. Lithium batteries can discharge to about 80 to 90% of their nominal capacity. Lead-acid batteries can discharge to about 50–60%. While flow batteries can discharge 100%. If batteries are used repeatedly even without mistreatment, they lose capacity as
21164-583: The Δ T and the Δ V charging methods, both manufacturers recommend a further period of trickle charging to follow the initial rapid charge. A resettable fuse in series with the cell, particularly of the bimetallic strip type, increases safety. This fuse opens if either the current or the temperature gets too high. Modern NiMH cells contain catalysts to handle gases produced by over-charging: However, this only works with overcharging currents of up to 0.1 C (that is, nominal capacity divided by ten hours). This reaction causes batteries to heat, ending
21312-478: Was gadolinite , a black mineral composed of cerium, yttrium, iron, silicon, and other elements. This mineral was extracted from a mine in the village of Ytterby in Sweden ; four of the rare-earth elements bear names derived from this single location. A table listing the 17 rare-earth elements, their atomic number and symbol, the etymology of their names, and their main uses (see also Applications of lanthanides )
21460-420: Was also developed by Waldemar Jungner in 1899; and commercialized by Thomas Edison in 1901 in the United States for electric vehicles and railway signalling . It is composed of only non-toxic elements, unlike many kinds of batteries that contain toxic mercury, cadmium, or lead. The nickel–metal hydride battery (NiMH) became available in 1989. These are now a common consumer and industrial type. The battery has
21608-478: Was found in the "ytterbite" (renamed to gadolinite in 1800) discovered by Lieutenant Carl Axel Arrhenius in 1787 at a quarry in the village of Ytterby , Sweden and termed "rare" because it had never yet been seen. Arrhenius's "ytterbite" reached Johan Gadolin , a Royal Academy of Turku professor, and his analysis yielded an unknown oxide ("earth" in the geological parlance of the day ), which he called yttria . Anders Gustav Ekeberg isolated beryllium from
21756-492: Was in fact still a mixture of oxides. In 1842 Mosander also separated the yttria into three oxides: pure yttria, terbia, and erbia (all the names are derived from the town name "Ytterby"). The earth giving pink salts he called terbium ; the one that yielded yellow peroxide he called erbium . In 1842 the number of known rare-earth elements had reached six: yttrium, cerium, lanthanum, didymium, erbium, and terbium. Nils Johan Berlin and Marc Delafontaine tried also to separate
21904-494: Was once thought to be in space group I 2 1 3 (no. 199), but is now known to be in space group Ia 3 (no. 206). The structure is similar to that of fluorite or cerium dioxide (in which the cations form a face-centred cubic lattice and the anions sit inside the tetrahedra of cations), except that one-quarter of the anions (oxygen) are missing. The unit cell of these sesquioxides corresponds to eight unit cells of fluorite or cerium dioxide, with 32 cations instead of 4. This
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