Upon charging a typical secondary Li-ion battery, the Li+ ions initially stored in the active material of the cathode are transported to the anode side. During this process, the cathode active material is oxidized and Li+ ions de-intercalate and diffuse through the electrolyte, towards the anode. This electrochemical process is induced by the applied charging potential, that drives the transport of free electrons through the cathode active material and through the binder with carbon black to the current collector. On the anode side, electrons flow from the current collector through the carbon black and active material. The active material of the anode is reduced by the Li+ intercalation.

During discharging, Li+ ions are transported in a corresponding process to the cathode side, while the electron flow powers the consumer device. The amount of lithium an electrode material can store per volume determines the volumetric energy density. The resulting cell potential is given by the difference between the electrochemical potential of the cathode and the electrochemical potential of the anode.