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99-421: Lithium polymer cells follow the history of lithium-ion and lithium-metal cells, which underwent extensive research during the 1980s, reaching a significant milestone with Sony 's first commercial cylindrical lithium-ion cell in 1991. After that, other packaging forms evolved, including the flat pouch format. Lithium polymer cells have evolved from lithium-ion and lithium-metal batteries. The primary difference

198-402: A {\displaystyle G={\frac {P^{2}}{2B}}{\frac {dC}{da}}} (1) where d C {\displaystyle dC} is the change in compliance C {\displaystyle C} (ratio of δ / P {\displaystyle \delta /P} ), B {\displaystyle B} is the thickness of the specimen, and d

297-478: A {\displaystyle G_{Ic}={\frac {nP_{C}\delta _{C}}{2Ba}}} (4) where n {\displaystyle n} is the slope of the least squares fit of log ⁡ ( C ) {\displaystyle \log(C)} vs. log ⁡ ( a ) {\displaystyle \log(a)} . Mode II interlaminar fracture toughness can be determined by an edge notch flexure test specified by ASTM D7905. The specimen

396-407: A {\displaystyle da} is the change in crack length. ASTM D5528 specifies the use of the double cantilever beam (DCB) specimen geometry for determining mode I interlaminar fracture toughness. A double cantilever beam specimen is created by placing a non-stick film between reinforcement layers in the center of the beam before curing the polymer matrix to create an initial crack of length

495-604: A 0 {\displaystyle a_{0}} . During the test the specimen is loaded in tension from the end of the initial crack side of the beam opening the crack. Using the compliance method, the critical strain energy release rate is given by G I c = 3 P C δ C 2 B a {\displaystyle G_{Ic}={\frac {3P_{C}\delta _{C}}{2Ba}}} (2) where P C {\displaystyle P_{C}} and δ C {\displaystyle \delta _{C}} are

594-484: A 3 {\displaystyle a^{3}} with the form of The candidate fracture toughness G Q {\displaystyle G_{Q}} equals the mode II fracture toughness G I I c {\displaystyle G_{IIc}} if strain energy release rate falls within certain percentage of G Q {\displaystyle G_{Q}} at different crack lengths specified by ASTM. Interlaminar shear strength

693-413: A balancing circuit until the battery is balanced. Balancing typically occurs whenever one or more cells reach their top-of-charge voltage before the other(s), as it is generally inaccurate to do so at other stages of the charge cycle. This is most commonly done by passive balancing, which dissipates excess charge as heat via resistors connected momentarily across the cells to be balanced. Active balancing

792-420: A conventional lithium-ion cell is graphite made from carbon . The positive electrode is typically a metal oxide or phosphate. The electrolyte is a lithium salt in an organic solvent . The negative electrode (which is the anode when the cell is discharging) and the positive electrode (which is the cathode when discharging) are prevented from shorting by a separator. The electrodes are connected to

891-401: A fracture plane that runs parallel to the surface. Once the fracture plane has developed, the concrete at the surface can separate from the substrate. Processing can create layers in materials which can fail by delamination. In concrete , surfaces can flake off from improper finishing. If the surface is finished and densified by troweling while the underlying concrete is bleeding water and air,

990-417: A gelled material, requiring fewer binding agents. This in turn shortens the manufacturing cycle. One potential application is in battery-powered airplanes. Another new development of lithium-ion batteries are flow batteries with redox-targeted solids, that use no binders or electron-conducting additives, and allow for completely independent scaling of energy and power. Generally, the negative electrode of

1089-414: A high molecular weight poly(trimethylene carbonate) (PTMC), polypropylene oxide (PPO), poly[bis(methoxy-ethoxy-ethoxy)phosphazene] (MEEP), etc . PEO exhibits the most promising performance as a solid solvent for lithium salts, mainly due to its flexible ethylene oxide segments and other oxygen atoms that comprise a strong donor character, readily solvating Li cations. PEO is also commercially available at

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1188-400: A higher discharge rate. NMC and its derivatives are widely used in the electrification of transport , one of the main technologies (combined with renewable energy ) for reducing greenhouse gas emissions from vehicles . M. Stanley Whittingham conceived intercalation electrodes in the 1970s and created the first rechargeable lithium-ion battery, based on a titanium disulfide cathode and

1287-400: A hot layer of plastic applied to a cold substrate layer can cause bending due to differential thermal contraction and layer separation. There are multiple nondestructive testing methods to detect delamination in structures including visual inspection , tap testing (i.e. sounding), ultrasound , radiography , and infrared imaging . Visual inspection is useful for detecting delaminations at

1386-404: A liquid solvent (such as propylene carbonate or diethyl carbonate ) is added. The electrolyte salt is almost always lithium hexafluorophosphate ( LiPF 6 ), which combines good ionic conductivity with chemical and electrochemical stability. The hexafluorophosphate anion is essential for passivating the aluminium current collector used for the positive electrode. A titanium tab

1485-506: A lithium-aluminium anode, although it suffered from safety problems and was never commercialized. John Goodenough expanded on this work in 1980 by using lithium cobalt oxide as a cathode. The first prototype of the modern Li-ion battery, which uses a carbonaceous anode rather than lithium metal, was developed by Akira Yoshino in 1985 and commercialized by a Sony and Asahi Kasei team led by Yoshio Nishi in 1991. M. Stanley Whittingham , John Goodenough , and Akira Yoshino were awarded

1584-524: A lithium-ion cell can change dramatically. Current effort has been exploring the use of novel architectures using nanotechnology to improve performance. Areas of interest include nano-scale electrode materials and alternative electrode structures. The reactants in the electrochemical reactions in a lithium-ion cell are the materials of the electrodes, both of which are compounds containing lithium atoms. Although many thousands of different materials have been investigated for use in lithium-ion batteries, only

1683-462: A longer cycle life , and a longer calendar life . Also noteworthy is a dramatic improvement in lithium-ion battery properties after their market introduction in 1991: over the following 30 years, their volumetric energy density increased threefold while their cost dropped tenfold. There are at least 12 different chemistries of Li-ion batteries; see " List of battery types ." The invention and commercialization of Li-ion batteries may have had one of

1782-735: A low volatile nature which also further contribute to safety. Cells with solid polymer electrolytes have not been fully commercialised and are still a topic of research. Prototype cells of this type could be considered to be between a traditional lithium-ion battery (with liquid electrolyte) and a completely plastic, solid-state lithium-ion battery . The simplest approach is to use a polymer matrix, such as polyvinylidene fluoride (PVdF) or poly(acrylonitrile) (PAN), gelled with conventional salts and solvents, such as LiPF 6 in EC / DMC / DEC . Nishi mentions that Sony started research on lithium-ion cells with gelled polymer electrolytes (GPE) in 1988, before

1881-424: A non-aqueous electrolyte is typically used, and a sealed container rigidly excludes moisture from the battery pack. The non-aqueous electrolyte is typically a mixture of organic carbonates such as ethylene carbonate and propylene carbonate containing complexes of lithium ions. Ethylene carbonate is essential for making solid electrolyte interphase on the carbon anode, but since it is solid at room temperature,

1980-537: A plasticizer in a microporous polymer matrix like poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methyl methacrylate) (PVDF-HFP/PMMA). Lithium-ion A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li ions into electronically conducting solids to store energy. In comparison with other commercial rechargeable batteries , Li-ion batteries are characterized by higher specific energy , higher energy density , higher energy efficiency ,

2079-449: A polymer gel as an electrolyte), a lithium cobalt oxide ( LiCoO 2 ) cathode material, and a graphite anode, which together offer high energy density. Lithium iron phosphate ( LiFePO 4 ), lithium manganese oxide ( LiMn 2 O 4 spinel , or Li 2 MnO 3 -based lithium-rich layered materials, LMR-NMC), and lithium nickel manganese cobalt oxide ( LiNiMnCoO 2 or NMC) may offer longer life and

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2178-446: A process called insertion ( intercalation ) or extraction ( deintercalation ), respectively. As the lithium ions "rock" back and forth between the two electrodes, these batteries are also known as "rocking-chair batteries" or "swing batteries" (a term given by some European industries). The following equations exemplify the chemistry (left to right: discharging, right to left: charging). The negative electrode half-reaction for

2277-529: A range of alternative materials, replaced TiS 2 with lithium cobalt oxide ( LiCoO 2 , or LCO), which has a similar layered structure but offers a higher voltage and is much more stable in air. This material would later be used in the first commercial Li-ion battery, although it did not, on its own, resolve the persistent issue of flammability. These early attempts to develop rechargeable Li-ion batteries used lithium metal anodes, which were ultimately abandoned due to safety concerns, as lithium metal

2376-484: A slightly longer crack with length a + Δ {\displaystyle a+\Delta } giving G I c = 3 P C δ C 2 B ( a + Δ ) {\displaystyle G_{Ic}={\frac {3P_{C}\delta _{C}}{2B(a+\Delta )}}} (3) The crack length correction Δ {\displaystyle \Delta } can be calculated experimentally by plotting

2475-465: A solid dry polymer electrolyte resembling a plastic-like film, replacing the traditional porous separator soaked with electrolyte. The solid electrolyte can typically be classified into three types: dry SPE, gelled SPE, and porous SPE. The dry SPE was the first used in prototype batteries, around 1978 by Michel Armand , and 1985 by ANVAR and Elf Aquitaine of France, and Hydro-Québec of Canada. Since 1990, several organisations, such as Mead and Valence in

2574-430: A solid organic electrolyte, polyethylene oxide , which was more stable. In 1985, Akira Yoshino at Asahi Kasei Corporation discovered that petroleum coke , a less graphitized form of carbon, can reversibly intercalate Li-ions at a low potential of ~0.5 V relative to Li+ /Li without structural degradation. Its structural stability originates from its amorphous carbon regions, which serving as covalent joints to pin

2673-636: A state of pure shear stress difficult to obtain in sample testing; thin cylindrical specimens can be used but are costly to manufacture. Sample geometries are thus chosen for ease of machining and optimization of the stress state when loaded. In addition to manufactured composites such as glass fiber-reinforced polymers , interlaminar shear strength is an important property in natural materials such as wood. The long, thin shape of floorboards, for example, may promote deformation that leads to vibrations. Asymmetric four-point bending (AFPB) may be chosen to measure interlaminar shear strength over other procedures for

2772-541: A temperature range of 5 to 45 °C (41 to 113 °F). Charging should be performed within this temperature range. At temperatures from 0 to 5 °C charging is possible, but the charge current should be reduced. During a low-temperature (under 0 °C) charge, the slight temperature rise above ambient due to the internal cell resistance is beneficial. High temperatures during charging may lead to battery degradation and charging at temperatures above 45 °C will degrade battery performance, whereas at lower temperatures

2871-523: A theoretical capacity of 1339 coulombs per gram (372 mAh/g). The positive electrode is generally one of three materials: a layered oxide (such as lithium cobalt oxide ), a polyanion (such as lithium iron phosphate ) or a spinel (such as lithium manganese oxide ). More experimental materials include graphene -containing electrodes, although these remain far from commercially viable due to their high cost. Lithium reacts vigorously with water to form lithium hydroxide (LiOH) and hydrogen gas. Thus,

2970-560: A variety of reasons, including specimen machinability, test reproducibility, and equipment availability. For example, short-beam shear samples are constrained to a specific length-thickness ratio to prevent bending failure, and the shear stress distribution across the specimen is non-uniform, both of which contribute to a lack of reproducibility. Rail shear testing also produces a non-homogeneous shear stress state, making it appropriate for determining shear modulus, but not shear strength. The Iosipescu test requires special equipment in addition to

3069-507: A very reasonable cost. The performance of these proposed electrolytes is usually measured in a half-cell configuration against an electrode of metallic lithium , making the system a " lithium-metal " cell. Still, it has also been tested with a common lithium-ion cathode material such as lithium-iron-phosphate (LiFePO 4 ). Other attempts to design a polymer electrolyte cell include the use of inorganic ionic liquids such as 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF 4 ) as

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3168-515: A very small number are commercially usable. All commercial Li-ion cells use intercalation compounds as active materials. The negative electrode is usually graphite , although silicon is often mixed in to increase the capacity. The electrolyte is usually lithium hexafluorophosphate , dissolved in a mixture of organic carbonates . A number of different materials are used for the positive electrode, such as LiCoO 2 , LiFePO 4 , and lithium nickel manganese cobalt oxides . During cell discharge

3267-632: Is 3.6 or 3.7 volts (about the middle value of the highest and lowest value) for cells based on lithium-metal-oxides (such as LiCoO 2 ). This compares to 3.6–3.8 V (charged) to 1.8–2.0 V (discharged) for those based on lithium-iron-phosphate (LiFePO 4 ). The exact voltage ratings should be specified in product data sheets, with the understanding that the cells should be protected by an electronic circuit that won't allow them to overcharge or over-discharge under use. LiPo battery packs , with cells connected in series and parallel, have separate pin-outs for every cell. A specialized charger may monitor

3366-440: Is a CuF 2 /Li battery developed by NASA in 1965. The breakthrough that produced the earliest form of the modern Li-ion battery was made by British chemist M. Stanley Whittingham in 1974, who first used titanium disulfide ( TiS 2 ) as a cathode material, which has a layered structure that can take in lithium ions without significant changes to its crystal structure . Exxon tried to commercialize this battery in

3465-417: Is a bit more than the heat of combustion of gasoline but does not consider the other materials that go into a lithium battery and that make lithium batteries many times heavier per unit of energy. Note that the cell voltages involved in these reactions are larger than the potential at which an aqueous solutions would electrolyze . During discharge, lithium ions ( Li ) carry the current within

3564-413: Is less common, more expensive, but more efficient, returning excess energy to other cells (or the entire pack) via a DC-DC converter or other circuitry. Balancing most often occurs during the constant voltage stage of charging, switching between charge modes until complete. The pack is usually fully charged only when balancing is complete, as even a single cell group lower in charge than the rest will limit

3663-634: Is maximised and delamination and deformation is prevented, which is associated with increase of cell impedance and degradation. LiPo cells provide manufacturers with compelling advantages. They can easily produce batteries of almost any desired shape. For example, the space and weight requirements of mobile devices and notebook computers can be met. They also have a low self-discharge rate of about 5% per month. LiPo batteries are now almost ubiquitous when used to power commercial and hobby drones ( unmanned aerial vehicles ), radio-controlled aircraft , radio-controlled cars , and large-scale model trains, where

3762-405: Is often at a premium. The longer cycle life, usable energy (Depth of discharge), and thermal runaway are also seen as a benefit of using Li-po batteries over VRLA batteries. The battery used to start a vehicle engine is typically 12 V or 24 V, so a portable jump starter or battery booster uses three or six LiPo batteries in series (3S1P/6S1P) to start the vehicle in an emergency instead of

3861-461: Is prepared in a similar manner as the DCB specimen introducing an initial crack with length a 0 {\displaystyle a_{0}} before curing the polymer matrix. If the test is performed with the initial crack (non-precracked method) the candidate fracture toughness G Q {\displaystyle G_{Q}} is given by where B {\displaystyle B}

3960-462: Is recommended to be initiated when voltage goes below 4.05 V/cell. Failure to follow current and voltage limitations can result in an explosion. Charging temperature limits for Li-ion are stricter than the operating limits. Lithium-ion chemistry performs well at elevated temperatures but prolonged exposure to heat reduces battery life. Li‑ion batteries offer good charging performance at cooler temperatures and may even allow "fast-charging" within

4059-408: Is that instead of using a liquid lithium-salt electrolyte (such as lithium hexafluorophosphate , LiPF 6 ) held in an organic solvent (such as EC / DMC / DEC ), the battery uses a solid polymer electrolyte (SPE) such as polyethylene glycol (PEG), polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA) or poly(vinylidene fluoride) (PVdF). In the 1970s, the original polymer design used

Lithium polymer battery - Misplaced Pages Continue

4158-435: Is the sample length, b {\displaystyle b} is the sample width (into the page as seen in a 2D free-body diagram), and t {\displaystyle t} is the sample thickness. The shear stress σ x z {\displaystyle \sigma _{xz}} in the sample is maximized in between the inner span of the pins and is given by The ratio of normal to shear stress in

4257-391: Is the thickness of the specimen and P max {\displaystyle P_{\max }} is the max load and m {\displaystyle m} is a fitting parameter. m {\displaystyle m} is determined by experimental results with a least squares fit of compliance C {\displaystyle C} vs. the crack length cubed

4356-410: Is ultrasonically welded to the aluminium current collector. Other salts like lithium perchlorate ( LiClO 4 ), lithium tetrafluoroborate ( LiBF 4 ), and lithium bis(trifluoromethanesulfonyl)imide ( LiC 2 F 6 NO 4 S 2 ) are frequently used in research in tab-less coin cells , but are not usable in larger format cells, often because they are not compatible with

4455-537: Is unstable and prone to dendrite formation, which can cause short-circuiting . The eventual solution was to use an intercalation anode, similar to that used for the cathode, which prevents the formation of lithium metal during battery charging. The first to demonstrate lithium ion reversible intercalation into graphite anodes was Jürgen Otto Besenhard in 1974. Besenhard used organic solvents such as carbonates, however these solvents decomposed rapidly providing short battery cycle life. Later, in 1980, Rachid Yazami used

4554-403: Is used as an additional measure of the strength of the fiber-matrix bond in fiber-reinforced composites. Shear-induced delamination is experienced in various loading conditions where the bending moment across the composite changes rapidly, such as in pipes with changes in thickness or bends. Multiple test architectures have been proposed for use in measuring interlaminar shear strength, including

4653-550: Is used in car-sharing schemes in several cities, also uses this type of battery. Lithium-ion batteries are becoming increasingly commonplace in Uninterruptible power supply (UPS) systems. They offer numerous benefits over the traditional VRLA battery , and with stability and safety improvements confidence in the technology is growing. Their power-to-size and weight ratio is seen as a major benefit in many industries requiring critical power backup, including data centers where space

4752-401: The constant current phase, the charger applies a constant current to the battery at a steadily increasing voltage, until the top-of-charge voltage limit per cell is reached. During the balance phase, the charger/battery reduces the charging current (or cycles the charging on and off to reduce the average current) while the state of charge of individual cells is brought to the same level by

4851-438: The other jump-start methods . The price of a lead-acid jump starter is less but they are bigger and heavier than comparable lithium batteries. So such products have mostly switched to LiPo batteries or sometimes lithium iron phosphate batteries. All Li-ion cells expand at high levels of state of charge (SOC) or overcharge due to slight vaporisation of the electrolyte. This may result in delamination and, thus, bad contact with

4950-692: The 2019 Nobel Prize in Chemistry "for the development of lithium-ion batteries". Jeff Dahn received the ECS Battery Division Technology Award (2011) and the Yeager award from the International Battery Materials Association (2016). In April 2023, CATL announced that it would begin scaled-up production of its semi-solid condensed matter battery that produces a then record 500 Wh/kg . They use electrodes made from

5049-476: The 2019 Nobel Prize in Chemistry for their contributions to the development of lithium-ion batteries. Lithium-ion batteries can be a safety hazard if not properly engineered and manufactured because they have flammable electrolytes that, if damaged or incorrectly charged, can lead to explosions and fires. Much progress has been made in the development and manufacturing of safe lithium-ion batteries. Lithium-ion solid-state batteries are being developed to eliminate

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5148-551: The United States and GS Yuasa in Japan, have developed batteries using gelled SPEs. In 1996, Bellcore in the United States announced a rechargeable lithium polymer cell using porous SPE. A typical cell has four main components: a positive electrode , a negative electrode, a separator, and an electrolyte . The separator itself may be a polymer , such as a microporous film of polyethylene (PE) or polypropylene (PP); thus, even when

5247-1124: The advantages of lower weight and increased capacity and power delivery justify the price. Test reports warn of the risk of fire when the batteries are not used per the instructions. The voltage for long-time storage of LiPo battery used in the R/C model should be 3.6~3.9 V range per cell, otherwise it may cause damage to the battery. LiPo packs also see widespread use in airsoft , where their higher discharge currents and better energy density than traditional NiMH batteries have very noticeable performance gain (higher rate of fire). LiPo batteries are pervasive in mobile devices , power banks , very thin laptop computers , portable media players , wireless controllers for video game consoles, wireless PC peripherals, electronic cigarettes , and other applications where small form factors are sought. The high energy density outweighs cost considerations. Hyundai Motor Company uses this type of battery in some of its battery-electric and hybrid vehicles and Kia Motors in its battery-electric Kia Soul . The Bolloré Bluecar , which

5346-434: The aluminium current collector. Copper (with a spot-welded nickel tab) is used as the current collector at the negative electrode. Current collector design and surface treatments may take various forms: foil, mesh, foam (dealloyed), etched (wholly or selectively), and coated (with various materials) to improve electrical characteristics. Depending on materials choices, the voltage , energy density , life, and safety of

5445-416: The area of non-flammable electrolytes as a pathway to increased safety based on the flammability and volatility of the organic solvents used in the typical electrolyte. Strategies include aqueous lithium-ion batteries , ceramic solid electrolytes, polymer electrolytes, ionic liquids, and heavily fluorinated systems. Research on rechargeable Li-ion batteries dates to the 1960s; one of the earliest examples

5544-399: The battery cell from the negative to the positive electrode, through the non- aqueous electrolyte and separator diaphragm. During charging, an external electrical power source applies an over-voltage (a voltage greater than the cell's own voltage) to the cell, forcing electrons to flow from the positive to the negative electrode. The lithium ions also migrate (through the electrolyte) from

5643-415: The cell has a liquid electrolyte, it will still contain a "polymer" component. In addition to this, the positive electrode can be further divided into three parts: the lithium-transition-metal-oxide (such as LiCoO 2 or LiMn 2 O 4 ), a conductive additive, and a polymer binder of poly(vinylidene fluoride) (PVdF). The negative electrode material may have the same three parts, only with carbon replacing

5742-413: The charge per cell so that all cells are brought to the same state of charge (SOC). Unlike lithium-ion cylindrical and prismatic cells, with a rigid metal case, LiPo cells have a flexible, foil-type (polymer laminate ) case, so they are relatively unconstrained. Moderate pressure on the stack of layers that compose the cell results in increased capacity retention, because the contact between the components

5841-416: The coated substrate. In laminated composites, the adhesion between layers often fails first, causing the layers to separate. For example, in fiber-reinforced plastics , sheets of high strength reinforcement (e.g., carbon fiber , fiberglass ) are bound together by a much weaker polymer matrix (e.g., epoxy ). In particular, loads applied perpendicular to the high strength layers, and shear loads can cause

5940-403: The commercialisation of the liquid-electrolyte lithium-ion cell in 1991. At that time, polymer batteries were promising, and it seemed polymer electrolytes would become indispensable. Eventually, this type of cell went into the market in 1998. However, Scrosati argues that, in the strictest sense, gelled membranes cannot be classified as "true" polymer electrolytes but rather as hybrid systems where

6039-401: The dense top layer may separate from the water and air pushing upwards. In steels , rolling can create a microstructure when the microscopic grains are oriented in flat sheets which can fracture into layers. Also, certain 3D printing methods (e.g., Fused Deposition ) builds parts in layers that can delaminate during printing or use. When printing thermoplastics with fused deposition, cooling

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6138-511: The entire battery's usable capacity to that of its own. Balancing can last hours or even days, depending on the magnitude of the imbalance in the battery. During the constant voltage phase, the charger applies a voltage equal to the maximum cell voltage times the number of cells in series to the battery, as the current gradually declines towards 0, until the current is below a set threshold of about 3% of initial constant charge current. Periodic topping charge about once per 500 hours. Top charging

6237-419: The external circuit toward the cathode where they recombine with the cathode material in a reduction half-reaction. The electrolyte provides a conductive medium for lithium ions but does not partake in the electrochemical reaction. The reactions during discharge lower the chemical potential of the cell, so discharging transfers energy from the cell to wherever the electric current dissipates its energy, mostly in

6336-481: The external circuit. During charging these reactions and transports go in the opposite direction: electrons move from the positive electrode to the negative electrode through the external circuit. To charge the cell the external circuit has to provide electrical energy. This energy is then stored as chemical energy in the cell (with some loss, e. g., due to coulombic efficiency lower than 1). Both electrodes allow lithium ions to move in and out of their structures with

6435-417: The failure along the length of the sample, but improper or nonsymmetrical machining can result in the addition of undesired normal stresses which reduce the measured strength. The sample is then loaded in compression in its test fixture, with loading applied directly to the sample from 4 loading pins arranged in a parallelogram-like configuration. The load applied from the test fixture is transferred unevenly to

6534-864: The flammable electrolyte. Improperly recycled batteries can create toxic waste, especially from toxic metals, and are at risk of fire. Moreover, both lithium and other key strategic minerals used in batteries have significant issues at extraction, with lithium being water intensive in often arid regions and other minerals used in some Li-ion chemistries potentially being conflict minerals such as cobalt . Both environmental issues have encouraged some researchers to improve mineral efficiency and find alternatives such as Lithium iron phosphate lithium-ion chemistries or non-lithium-based battery chemistries like iron-air batteries . Research areas for lithium-ion batteries include extending lifetime, increasing energy density, improving safety, reducing cost, and increasing charging speed, among others. Research has been under way in

6633-470: The graphite is The positive electrode half-reaction in the lithium-doped cobalt oxide substrate is The full reaction being The overall reaction has its limits. Overdischarging supersaturates lithium cobalt oxide , leading to the production of lithium oxide , possibly by the following irreversible reaction: Overcharging up to 5.2  volts leads to the synthesis of cobalt (IV) oxide, as evidenced by x-ray diffraction : The transition metal in

6732-562: The greatest impacts of all technologies in human history , as recognized by the 2019 Nobel Prize in Chemistry . More specifically, Li-ion batteries enabled portable consumer electronics , laptop computers , cellular phones , and electric cars , or what has been called the e-mobility revolution. It also sees significant use for grid-scale energy storage as well as military and aerospace applications. Lithium-ion cells can be manufactured to optimize energy or power density. Handheld electronics mostly use lithium polymer batteries (with

6831-436: The interlaminar matrix. During the tests load P {\displaystyle P} and displacement δ {\displaystyle \delta } is recorded for analysis to determine the strain energy release rate from the compliance method . G {\displaystyle G} in terms of compliance is given by G = P 2 2 B d C d

6930-615: The internal layers of the cell, which in turn diminishes the reliability and overall cycle life. This is very noticeable for LiPos, which can visibly inflate due to the lack of a hard case to contain their expansion. Lithium polymer batteries' safety characteristics differ from those of lithium iron phosphate batteries . Polymer electrolytes can be divided into two large categories: dry solid polymer electrolytes (SPE) and gel polymer electrolytes (GPE). In comparison to liquid electrolytes and solid organic electrolytes, polymer electrolytes offer advantages such as increased resistance to variations in

7029-443: The internal resistance of the battery may increase, resulting in slower charging and thus longer charging times. Batteries gradually self-discharge even if not connected and delivering current. Li-ion rechargeable batteries have a self-discharge rate typically stated by manufacturers to be 1.5–2% per month. The rate increases with temperature and state of charge. A 2004 study found that for most cycling conditions self-discharge

7128-491: The ionic conductivity at room temperature, gelled electrolyte is added resulting in the formation of GPEs. GPEs are formed by incorporating an organic liquid electrolyte in the polymer matrix. Liquid electrolyte is entrapped by a small amount of polymer network, hence the properties of GPE is characterized by properties between those of liquid and solid electrolytes. The conduction mechanism is similar for liquid electrolytes and polymer gels, but GPEs have higher thermal stability and

7227-564: The late 1970s, but found the synthesis expensive and complex, as TiS 2 is sensitive to moisture and releases toxic H 2 S gas on contact with water. More prohibitively, the batteries were also prone to spontaneously catch fire due to the presence of metallic lithium in the cells. For this, and other reasons, Exxon discontinued the development of Whittingham's lithium-titanium disulfide battery. In 1980, working in separate groups Ned A. Godshall et al., and, shortly thereafter, Koichi Mizushima and John B. Goodenough , after testing

7326-435: The layers together. Although it has a lower capacity compared to graphite (~Li0.5C6, 186 mAh g–1), it became the first commercial intercalation anode for Li-ion batteries owing to its cycling stability. In 1987, Yoshino patented what would become the first commercial lithium-ion battery using this anode. He used Goodenough's previously reported LiCoO 2 as the cathode and a carbonate ester -based electrolyte. The battery

7425-587: The least squares fit of the cube root of the compliance C 1 / 3 {\displaystyle C^{1/3}} vs. crack length a {\displaystyle a} . The correction Δ {\displaystyle \Delta } is the absolute value of the x intercept. Fracture toughness can also be corrected with the compliance calibration method where G I c {\displaystyle G_{Ic}} given by G I c = n P C δ C 2 B

7524-439: The lengths from the inner pin to the applied point load and from the outer pin to the applied point load, respectively. The normal stress in the sample σ x x {\displaystyle \sigma _{xx}} is maximized at the locations of the inner pins, and is equivalent to where F {\displaystyle F} is the total applied load on the sample, L {\displaystyle L}

7623-425: The liquid electrolyte providing a conductive medium. To prevent the electrodes from touching each other directly, a microporous separator is in between, which allows only the ions and not the electrode particles to migrate from one side to the other. The voltage of a single LiPo cell depends on its chemistry and varies from about 4.2 V (fully charged) to about 2.7–3.0 V (fully discharged). The nominal voltage

7722-402: The liquid phases are contained within the polymer matrix. Although these polymer electrolytes may be dry to the touch, they can still include 30% to 50% liquid solvent. In this regard, how to define a "polymer battery" remains an open question. Other terms used in the literature for this system include hybrid polymer electrolyte (HPE), where "hybrid" denotes the combination of the polymer matrix,

7821-449: The liquid solvent, and the salt. It was a system like this that Bellcore used to develop an early lithium-polymer cell in 1996, which was called a "plastic" lithium-ion cell (PLiON) and subsequently commercialised in 1999. A solid polymer electrolyte (SPE) is a solvent-free salt solution in a polymer medium. It may be, for example, a compound of lithium bis(fluorosulfonyl)imide (LiFSI) and high molecular weight poly(ethylene oxide) (PEO),

7920-425: The lithium-metal-oxide. The main difference between lithium-ion polymer cells and lithium-ion cells is the physical phase of the electrolyte, such that LiPo cells use dry solid, gel-like electrolytes, whereas Li-ion cells use liquid electrolytes. Like other lithium-ion cells, LiPos work on the intercalation and de-intercalation of lithium ions from a positive electrode material and a negative electrode material, with

8019-443: The maximum load and displacement respectively by determining when the load deflection curve has become nonlinear with a line drawn from the origin with a 5% increase in compliance. Typically, equation 2 overestimates the fracture toughness because the two cantilever beams of the DCB specimen will have a finite rotation at the crack. The finite rotation can be corrected for by calculating G {\displaystyle G} with

8118-428: The negative electrode is the anode and the positive electrode the cathode : electrons flow from the anode to the cathode through the external circuit. An oxidation half-reaction at the anode produces positively charged lithium ions and negatively charged electrons. The oxidation half-reaction may also produce uncharged material that remains at the anode. Lithium ions move through the electrolyte; electrons move through

8217-662: The pitch of the produced sound, influencing the inspection. Some of these variations include ply overlaps, ply count change gores, core density change (if used), and geometry. In reinforced concretes intact regions will sound solid whereas delaminated areas will sound hollow. Tap testing large concrete structures is carried about either with a hammer or with a chain dragging device for horizontal surfaces like bridge decks. Bridge decks in cold climate countries which use de-icing salts and chemicals are commonly subject to delamination and as such are typically scheduled for annual inspection by chain-dragging as well as subsequent patch repairs of

8316-425: The polymer matrix to fracture or the fiber reinforcement to debond from the polymer. Delamination also occurs in reinforced concrete when metal reinforcements near the surface corrode. The oxidized metal has a larger volume causing stresses when confined by the concrete. When the stresses exceed the strength of the concrete, cracks can form and spread to join with neighboring cracks caused by corroded rebar creating

8415-410: The positive electrode, cobalt ( Co ), is reduced from Co to Co during discharge, and oxidized from Co to Co during charge. The cell's energy is equal to the voltage times the charge. Each gram of lithium represents Faraday's constant /6.941, or 13,901 coulombs. At 3 V, this gives 41.7 kJ per gram of lithium, or 11.6 kWh per kilogram of lithium. This

8514-492: The positive to the negative electrode where they become embedded in the porous electrode material in a process known as intercalation . Energy losses arising from electrical contact resistance at interfaces between electrode layers and at contacts with current collectors can be as high as 20% of the entire energy flow of batteries under typical operating conditions. The charging procedures for single Li-ion cells, and complete Li-ion batteries, are slightly different: During

8613-432: The powered circuit through two pieces of metal called current collectors. The negative and positive electrodes swap their electrochemical roles ( anode and cathode ) when the cell is charged. Despite this, in discussions of battery design the negative electrode of a rechargeable cell is often just called "the anode" and the positive electrode "the cathode". In its fully lithiated state of LiC 6 , graphite correlates to

8712-453: The presence of ethylene carbonate solvent (which is solid at room temperature and is mixed with other solvents to make a liquid). This represented the final innovation of the era that created the basic design of the modern lithium-ion battery. In 2010, global lithium-ion battery production capacity was 20 gigawatt-hours. By 2016, it was 28 GWh, with 16.4 GWh in China. Global production capacity

8811-412: The presence of delamination due to the defect dampening the impact. Tap testing is well suited for finding large defects in flat panel composites with a honeycomb core whereas thin laminates may have small defects that are not discernible by sound. Using sound is also subjective and dependent on the inspector's quality of hearing as well as judgement. Any intentional variations in the part may also change

8910-399: The roller setup already used for other three- and four-point flexural tests. ASTM C1469 outlines a standard for AFPB testing of advanced ceramic joints, and the method has been proposed to be adapted for use with continuous ceramic matrix composites . Rectangular samples can be used with or without notches machined at the center; the addition of notches helps to control the position of

9009-400: The short beam shear test, Iosipescu test, rail shear test, and asymmetrical four-point bending test. The goal of each of these tests is to maximize the ratio of shear stress to tensile stress exhibited in the sample, promoting failure via delamination of the fiber-matrix interface instead of through fiber tension or buckling . The orthotropic symmetry of fiber composite materials makes

9108-402: The surface and edges of materials. However, a visual inspection may not detect delamination within a material without cutting the material open. Tap testing or sounding involves gently striking the material with a hammer or hard object to find delamination based on the resulting sound. In laminated composites, a clear ringing sound indicates a well bonded material whereas a duller sound indicates

9207-882: The surface. ASTM provides standards for paint adhesion testing which provides qualitative measures for paints and coatings resistance to delamination from substrates. Tests include cross-cut test, scrape adhesion, and pull-off test . Fracture toughness is a material property that describes resistance to fracture and delamination. It is denoted by critical stress intensity factor K c {\displaystyle K_{c}} or critical strain energy release rate G c {\displaystyle G_{c}} . For unidirectional fiber reinforced polymer laminate composites , ASTM provides standards for determining mode I fracture toughness G I C {\displaystyle G_{IC}} and mode II fracture toughness G I I C {\displaystyle G_{IIC}} of

9306-407: The top two pins; the ratio of the inner pin load P {\displaystyle P} and outer pin load Q {\displaystyle Q} is defined as the loading factor λ {\displaystyle \lambda } , such that where S 1 {\displaystyle S_{1}} and S 2 {\displaystyle S_{2}} are

9405-483: The volume of the electrodes throughout the charge and discharge processes, improved safety features, excellent flexibility, and processability. Solid polymer electrolyte was initially defined as a polymer matrix swollen with lithium salts, now called dry solid polymer electrolyte. Lithium salts are dissolved in the polymer matrix to provide ionic conductivity. Due to its physical phase, there is poor ion transfer, resulting in poor conductivity at room temperature. To improve

9504-419: Was 767 GWh in 2020, with China accounting for 75%. Production in 2021 is estimated by various sources to be between 200 and 600 GWh, and predictions for 2023 range from 400 to 1,100 GWh. In 2012, John B. Goodenough , Rachid Yazami and Akira Yoshino received the 2012 IEEE Medal for Environmental and Safety Technologies for developing the lithium-ion battery; Goodenough, Whittingham, and Yoshino were awarded

9603-630: Was assembled in the discharged state, which made it safer and cheaper to manufacture. In 1991, using Yoshino's design, Sony began producing and selling the world's first rechargeable lithium-ion batteries. The following year, a joint venture between Toshiba and Asashi Kasei Co. also released a lithium-ion battery. Significant improvements in energy density were achieved in the 1990s by replacing Yoshino's soft carbon anode first with hard carbon and later with graphite. In 1990, Jeff Dahn and two colleagues at Dalhousie University (Canada) reported reversible intercalation of lithium ions into graphite in

9702-788: Was estimated at 2% to 3%, and 2 –3% by 2016. By comparison, the self-discharge rate for NiMH batteries dropped, as of 2017, from up to 30% per month for previously common cells to about 0.08–0.33% per month for low self-discharge NiMH batteries, and is about 10% per month in NiCd batteries . Delamination Delamination is a mode of failure where a material fractures into layers. A variety of materials, including laminate composites and concrete , can fail by delamination. Processing can create layers in materials, such as steel formed by rolling and plastics and metals from 3D printing which can fail from layer separation. Also, surface coatings , such as paints and films, can delaminate from

9801-484: Was primarily time-dependent; however, after several months of stand on open circuit or float charge, state-of-charge dependent losses became significant. The self-discharge rate did not increase monotonically with state-of-charge, but dropped somewhat at intermediate states of charge. Self-discharge rates may increase as batteries age. In 1999, self-discharge per month was measured at 8% at 21 °C, 15% at 40 °C, 31% at 60 °C. By 2007, monthly self-discharge rate

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