Lithium-ion Batteries

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In the past few decades, Li-ion batteries have gained a lot of attention as one of the most cutting-edge rechargeable batteries. They are now the only mobile power sources utilized in cell phones and laptop computers, making them the standard for portable electronic devices. Twenty years ago, at the same time as Li-ion batteries were first commercialized, Li-ion batteries are regarded as the engine of the personal digital electronic revolution. In terms of gravimetric and volumetric energy, Li-ion batteries are far superior to other commercial rechargeable batteries. Because of the benefits they provide, Li-ion batteries are anticipated to continue to dominate the market for rechargeable batteries for at least a decade more.

Li-ion batteries have a flexible architecture. To effectively suit the limited space in the devices they power, they can be shaped into a broad range of forms and sizes. Unlike Ni-Cd batteries, Li-ion batteries do not have the memory effect issue. Compared to normal Ni-based batteries, Li-ion batteries have voltages that are over three times higher. These batteries feature relatively flexible charging and discharging control, so they don't need to be fully charged or fully drained.


Oxidation-reduction (Redox) processes occur within a lithium-ion battery. Reduction occurs at the cathode. Cobalt oxide mixes with lithium ions in this reaction to generate lithium-cobalt oxide (LiCoO2). The anode is where oxidation occurs. LiC6, a graphite intercalation chemical, generates graphite (C6) and lithium ions there.

Operation


A lithium-ion battery, often known as a Li-ion battery, is a kind of rechargeable battery made up of cells in which lithium ions travel from the negative electrode to the positive electrode through an electrolyte during discharge and back again during charging. The positive electrode in lithium-ion batteries is made of an intercalated lithium compound, whereas the negative electrode is commonly made of graphite. Other than LFP cells, lithium-ion batteries have no memory effect, a high energy density, and a low self-discharge rate. Cells can be designed to prioritize either energy or power density.


Lithium is a thin, light metal that permits simple electric current flow. Because their chemical processes are reversible and allow them to collect electricity and discharge it later, lithium ions are what make batteries rechargeable. Large amounts of energy may be stored in lithium-ion batteries, which also maintain their charge longer than other types of batteries.




The key features of a Li-Ion battery are explained below.


High Energy Density

Compared to lead-acid batteries, lithium-ion batteries have a 3 times higher energy density per unit weight. This is mostly because lithium has a lower atomic weight than lead (209), at 6.9. A lithium-ion battery has a maximum storage capacity of 120wh/kg, compared to a lead-acid battery 40wh/kg.


Depth of Discharge (DoD)

The difference between the quantity of energy that has been utilized and the battery's overall capacity is known as the DoD. To preserve the battery's health, the majority of batteries come with a suggested DoD. Because lithium-ion batteries are deep-cycle batteries, their DoDs are in the range of 95%. The DoD of many lead acid batteries is only 50%. This implies that a lithium-ion battery can store more energy, allowing you to utilize more of it without constantly charging it.


Low Self-Discharge

The self-discharge rate is one concern with many rechargeable batteries. One advantage of lithium-ion batteries is that they self-discharge at a considerably slower pace than other rechargeable cell types like Ni-Cad and NiMH. In the first four hours after being charged, it is normally around 5%, but after that, it decreases to a rate of 1 or 2 percent every month.


Better Life Span

Because of the DoD, the batteries have a minimum warrantied lifespan of roughly 10 years, or a cycle of 10,000 cycles-whichever comes first, and they don't need to be charged and recharged as frequently.