The origin and fundamentals of lithium-ion batteries
Lithium-ion batteries are a type of rechargeable battery in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging.
Lead-acid batteries were developed and used in the 1800s before lithium-ion batteries became popular in the 1990s. Subsequently, NiCd and NiMH batteries were introduced and accepted for their better performance.
However, there is still a need for a battery that can be easily and timely recharged. In 1991, after long-term research by different scientists around the world, the lithium-ion battery was finally invented. These batteries quickly became popular and they are now widely accepted in the market.
Lithium-ion batteries contain one or more power-generating blocks called cells. A battery has the following main components: cathode (positive electrode), anode (negative electrode), electrolyte, separator, positive terminal (positive current collector) and negative terminal (negative current collector).
The anode and cathode store lithium, and the electrolyte carries positively charged lithium ions from the anode to the cathode through the separator, and vice versa. The movement of lithium ions generates free electrons in the anode, which creates a charge at the positive terminal. Current then flows from the collector through the device being powered to the negative terminal. Separators prevent the flow of electrons inside the battery.
When the battery discharges and supplies current, the anode releases lithium ions to the cathode, creating a flow of electrons from one side to the other. When the device is plugged in, the opposite happens: lithium ions are released by the cathode and received by the anode.
