The electrolyte in a battery is the medium that allows ions to flow between the positive and negative electrodes during charging and discharging. In a typical lithium-ion battery, the electrolyte is a liquid solution consisting of a lithium salt (like LiPF₆) dissolved in organic solvents (like a mixture of carbonates such as EC, DMC, etc.). The electrolyte must be chemically stable within the battery’s operating voltage window and temperature range, and assist with forming a stable solid electrolyte interface (SEI) on the anode electrode. The properties of the electrolyte—ionic conductivity, viscosity, electrochemical stability, etc.—greatly affect a battery’s performance, including its internal resistance, operating temperature range, charge rate, and safety.
