Electrolyte additive, electrolyte and lithium secondary battery

The invention relates to the field of lithium secondary batteries, in particular to an electrolyte additive, which is used as a bifunctional electrolyte additive, not only has excellent film forming performance, but also can effectively remove H2O and HF in an electrolyte and improve the stability of an electrode/electrolyte interface, so that the battery performance is improved. The invention also discloses an electrolyte and a lithium secondary battery. 本申请涉及锂二次电池领域，尤其涉及一种电解液添加剂，本申请提供的添加剂作为双功能电解液添加剂，其不仅具有优异的成膜性能，而且可以有效清除电解质中的H2O和HF，提高电极/电解液界面的稳定性，从而提高电池性能。此外还公开了一种电解液和一种锂二次电池。