A lithium-ion cell consists of anode, cathode, separator, electrolyte and current collectors. The cell components are sealed inside of an airtight container. The container can be a cylindrical or prismatic metal can or a pouch made of aluminum foil.
Lithium ions are stored in the active anode and cathode materials. Electrolyte is typically a solution consisting of organic solvents and a lithium salt. In the cell, electrolyte carries the lithium ions between the anode and cathode during operation. Separator is a thin polymer film which prevents direct contact between the anode and cathode but allows lithium ions to go through it.
When the cell is charged, lithium ions move from cathode to anode through the electrolyte and separator. Simultaneously, a corresponding amount of charge flows as electrons through the current collectors and external circuit. Upon discharge, lithium ions and electrons move to opposite direction, from anode to cathode, and provide current to the powered device, such as a smart phone, laptop or an EV car.