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Lithium-ion Battery

A lithium-ion battery, also known as the Li-ion battery, is a type of secondary (rechargeable) battery composed of cells in which lithium ions move from the anode through an electrolyte to the cathode during discharge and back when charging. 

The cathode is made of a composite material (an intercalated lithium compound) and defines the name of the Li-ion battery cell. The anode is usually made out of porous lithiated graphite. The electrolyte can be liquid, polymer, or solid. The separator is porous to enable the transport of lithium ions and prevents the cell from short-circuiting and thermal runaway.

Chemistry, performance, cost, and safety characteristics vary across types of lithium-ion batteries. Handheld electronics mostly use lithium polymer batteries (with a polymer gel as electrolyte), a lithium cobalt oxide (LiCoO2) cathode material, and a graphite anode, which offer high energy density.

Lithium batteries show the largest market growth of all other batteries and have successfully displaced the competing systems. Lithium secondary batteries (lithium-ion batteries) provide multiple reversible transformation of chemical energy into electrical energy so that these batteries can be often used. Lithium-ion batteries, unlike conventional batteries, do not have a memory effect (loss of capacity by not complete loading/unloading) and achieve high efficiency of up to 95% (ratio of discharge to charge amount). The problem with these batteries is their lifespan, which is typically defined as the number of full charge-discharge cycles to reach a failure threshold in terms of capacity loss or impedance rise. After 500 cycles, the capacity of lithium-ion batteries begins to drop, and the capacity is reduced to around 50% after 1200-150

Types of Lithium-ion Batteries for BESS

The cathode is made of a composite material (an intercalated lithium compound) and defines the name of the Li-ion battery cell. There are two kinds of electrodes: intercalation and conversion electrodes. The intercalation electrodes are materials that function as host materials where lithium ions can intercalate. A typical example is LiCoO₂ and its derivatives. Conversion-type cathode materials are some of the key candidates for the next generation of rechargeable Li and Li-ion batteries.

One of the most common lithium batteries is:

• Lithium Cobalt Oxide (LiCoO₂).  LiCoO₂ is the most commonly used cathode material. LiCoO₂ batteries have very stable capacities, although their capacities are lower than those based on nickel-cobalt-aluminum (NCA) oxides. However, cobalt is relatively expensive compared to other transition metals, such as manganese and iron, despite the attractive electrical properties of LiCoO2 cathodes. Currently, we can find this type of battery in mobile phones, tablets, laptops, and cameras.
• Lithium Manganese Oxide (LiMn₂O₄). LiMn₂O₄ is a promising cathode material with a cubic spinel structure. LiMn₂O₄ is one of the most studied manganese oxide-based cathodes because it contains inexpensive materials. A further advantage of this battery is enhanced safety and high thermal stability, but the cycle and calendar life is limited. This type of battery is found in power tools, medical devices, and powertrains.
• Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO₂) – NMC. Nickel manganese cobalt (NMC) batteries contain a cathode made of a combination of nickel, manganese, and cobalt. NMC is one of the most successful cathode combinations in Li-ion systems. It can be tailored to serve as energy cells or power cells like Li-manganese. NMC batteries are used for power tools, e-bikes, and other electric powertrains.
• Lithium Iron Phosphate (LiFePO₄) – LFP. LiFePO₄ is one of the most recent cathode materials to be introduced. As of 2017, LiFePO₄ is a candidate for large-scale production of lithium-ion batteries, such as electric vehicle applications, due to its low cost, excellent safety, and high cycle durability. The energy density of an LFP battery is lower than that of other common lithium-ion battery types, such as Nickel Manganese Cobalt (NMC). Because of their lower cost, high safety, low toxicity, long cycle life, and other factors, LFP batteries are finding a number of roles in vehicle use, utility-scale stationary applications, and backup power. Working voltage = 3.0 ~ 3.3 V. Cycle life ranges from 2,700 to more than 10,000 cycles depending on conditions.
• Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO₂) – NCA. In 1999, Lithium nickel cobalt aluminum oxide battery, or NCA, appeared in some special applications, and it is similar to the NMC. It offers high specific energy, a long life span, and a reasonably good specific power. NCA’s usable charge storage capacity is about 180 to 200 mAh/g. The capacity of NCA is significantly higher than that of alternative materials such as LiCoO₂ with 148 mAh/g, LiFePO₄ with 165 mAh/g, and NMC 333 (LiNi_0,33Mn_0,33Co_0,33O₂)with 170 mAh/g. The voltage of these batteries is between 3.6 V and 4.0 V, at a nominal voltage of 3.6 V or 3.7 V. Another advantage of NCA is its excellent fast charging capability. Nevertheless, its weak points are the limited resources of cobalt and nickel and the high cost.