Generally, the negative electrode of a conventional lithium-ion cell is made from. The positive electrode is typically a metal or phosphate. The is a in an. The negative electrode (which is the when the cell is discharging) and the positive electrode (which is the when discharging) are prevented from shorting by a separator. The electrodes are connected to the powered circuit through two pieces of. Generally, the negative electrode of a conventional lithium-ion cell is made from. The positive electrode is typically a metal or phosphate. The is a in an. The negative electrode (which is the when the cell is discharging) and the positive electrode (which is the when discharging) are prevented from shorting by a separator. The electrodes are connected to the powered circuit through two pieces of metal called current collectors. The negative and positive electrodes swap their electrochemical roles ( and ) 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 LiC6, graphite correlates to a theoretical capacity of 1339 per gram (372 mAh/g). The positive electrode is generally one of three materials: a layered (such as ), a (such as A lithium-ion or Li-ion battery is a type of that uses the reversible of Li ions into solids to store energy. In comparison with other commercial, Li-ion batteries are characterized by higher, higher, higher, a longer, and a longer. 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. In late 2024 global demand passed 1 per year, while production capacity was more than twice that. The invention and commercialization of Li-ion batteries may have had one of the greatest impacts of all, as recognized by the 2019. More specifically, Li-ion batteries enabled portable,,, and. Li-ion batteries also see significant use for as well as military and applications. Lithium-ion cells can be manufactured to optimize energy or power density. Handheld electronics mostly use (with a polymer gel as an electrolyte), a (LiCoO 2) cathode material, and a anode, which together offer high energy density. (LiFePO 4), (LiMn 2O 4, or Li 2MnO 3-based lithium-rich layered materials, LMR-NMC), and (LiNiMnCoO 2 or NMC) may offer longer life and a higher discharge rate. NMC and its derivatives are widely used in the, one of the main technologies (combined with ) for reducing. conceived electrodes in the 1970s and created the first rechargeable lithium-ion battery, based on a cathode and a lithium-aluminium anode, although it suffered from safety problems and was never commercialized. expanded on this work in 1980 by using as a cathode. The first prototype of the modern Li-ion battery, which uses a carbonaceous anode rather than lithium metal, was developed by in 1985 and commercialized by a and team led by Yoshio Nishi in 1991. Whittingham, Goodenough, and Yoshino were awarded the 2019 for their contributions to the development of lithium-ion batteries. Lithium-ion batteries can be a safety hazard if not properly en. Research on rechargeable Li-ion batteries dates to the 1960s; one of the earliest examples is a CuF 2/Li battery developed by in 1965. The breakthrough that produced the earliest form of the modern Li-ion battery was made by British chemist in 1974, who first used (TiS 2) as a cathode material, which has a layered structure that can without significant changes to its. tried to commercialize this battery in the late 1970s, but found the synthesis expensive and complex, as TiS 2 is sensitive to moisture and releases toxic 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, and, after testing a range of alternative materials, replaced TiS 2 with (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 is unstable and prone to formation, which can cause. 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, used a solid organic electrolyte,, which was more stable. In 1985, at Corporation discovered that, 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 regions, which serving as covalent joints to pin 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 as the cathode and a -based electrolyte. The battery was assembled in the discharged state, which made it safer and cheaper to manufacture. In 1991, using Yoshino's design, began producing and selling the world's first rechargeable lithium-ion batteries. The following year, a between and 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 and later with graphite. In 1990, and two colleagues at (Canad. Lithium-ion batteries may have multiple levels of structure. Small batteries consist of a single battery cell. Larger batteries connect cells into a module and connect modules and parallel into a pack. Multiple packs may be connected to increase the voltage. On the macrostructral level (length scale 0.1-5 mm) almost all commercial lithium-ion batteries comprise foil current collectors ( for and for ). Copper is selected for the anode, because lithium does not alloy with it. Aluminum is used for the cathode, because it passivates in LiPF6 electrolytes. Li-ion cells are available in various form factors, which can generally be divided into four types: • Coin cells have a rugged design with metal (stainless steel, usually) casing. Because of their poor (in Wh/kg) and small energy (Wh) per cell, their use is limited to handwatches, portable calculators and research. Notably, coin format cells are more commonly used for primary lithium-metal batteries.• Small cylindrical (solid body without terminals, such as those used in most and most and older laptop batteries); they typically come in.• Large cylindrical (solid body with large threaded terminals)• Flat or pouch (soft, flat body, such as those used in cell phones and newer laptops; these are. • Rigid plastic case with large threaded terminals (such as electric vehicle traction packs)Cells with a cylindrical shape are made in a characteristic "" manner (known as a "jelly roll" in the US), which means it is a single long "sandwich" of the positive electrode, separator, negative electrode, and separator rolled into a single spool. The result is encased in a container. One advantage of cylindrical cells is faster production speed. One disadvantage can be a large radial temperature gradient at high discharge rates. The absence of a case gives pouch cells the highest gravimetric energy density; however, many applications require containment to prevent expansion when their (SOC) level is high, and for general structural stability. Both rigid plastic and pouch-style cells are sometimes referred to as cells due to their rectangular shapes. Three basic battery types are used in 2020s-era electric vehicles: cylindrical cells (e.g., Tesla), prismatic pouch (e.g., from ), and prismatic can cells (e.g., from LG,,, and others). have been demonstrated that suspe. Lithium ion batteries are used in a multitude of applications from, toys, power tools and electric vehicles. More niche uses include backup power in telecommunications applications. Lithium-ion batteries are also frequently discussed as a potential option for, although as of 2020, they were not yet cost-competitive at scale.
