This application provides a nonaqueous electrolyte, a lithium-ion battery, a battery module, a battery pack, and an apparatus. The nonaqueous electrolyte includes a nonaqueous solvent, a lithium salt, and an additive, where the nonaqueous solvent includes a carbonate solvent and a high oxidation potential solvent, and the additive includes cyclic sulfate. The high oxidation potential solvent is selected from one or more of compounds represented by formula I and formula II, and the cyclic sulfate may be selected from one or more of compounds represented by formula III. This application can not only improve electrochemical performance of the lithium-ion battery under high temperature and high voltage and improve safety performance such as overcharge safety and hot box safety of the lithium-ion battery, but also ensure that the lithium-ion battery has some kinetic performance.