ELECTROLYTE ADDITIVE, BATTERY ELECTROLYTE AND USE THEREOF

Disclosed in the present application are an electrolyte additive, a battery electrolyte and the use thereof. The electrolyte additive comprises a free-radical capturing agent, wherein the free-radical capturing agent comprises at least one of the following structural formulas I to II. Since the provided free-radical capturing agent having the structural formulas I to II stably carries a nitrogen free radical or an oxygen free radical, the free-radical capturing agent, when used in an electrolyte, can consume harmful groups, which are generated during charging and discharging processes of a secondary battery, such as a CH3· free radical, an acyl free radical and a CH3O· free radical, and can effectively inhibit the generation of active oxygen of a positive electrode additive in a secondary battery, thereby effectively inhibiting the gas production phenomenon of a secondary battery during charging and discharging, such that the gas production amount is significantly reduced, and the volume expansion of the seco