Lithium is the least dense metallic element, making it able to pack more power in a small space than other types of battery. Lithium is also highly reactive, causing it to be combustible. In a lithium cell the electrolyte is a solution of lithium salts and organic solvents. When the battery is charged, lithium ions are driven from the electrolyte solution into a carbon anode, and when the battery is discharged ions flow back, creating a balancing flow of electrons in a circuit that powers the device.
If there is a small fault or damage in the extremely thin separators that keep the elements of the battery apart, an internal short-circuit can occur causing a build-up of heat and what is known as “thermal runaway,” in which the battery can burst into flame. Lithium batteries can also be damaged by using them in hot environments and by excessive discharging and charging. Running down a lithium-ion battery can also completely destroy it. For this reason, manufacturers have installed smart control systems to monitor battery temperature and regulate their charging and discharging.
If lithium comes in contact with water..