This application provides an electrolyte, a lithium-ion battery, and an apparatus containing the lithium-ion battery. The electrolyte includes a lithium salt, an organic solvent, and an additive. The additive includes a sulfur-containing compound and lithium difluorophosphate, and a reduction potential of the sulfur-containing compound is higher than a reduction potential of lithium difluorophosphate. Because the reduction potential of the sulfur-containing compound is higher than the reduction potential of lithium difluorophosphate, the sulfur-containing compound can form a low-impedance SEI film on a surface of a negative electrode prior to lithium difluorophosphate, allowing more lithium difluorophosphate to form a passivation film with good thermostability on a surface of a positive electrode, so that the lithium-ion battery has good high-temperature storage performance and cycling performance, without suffering performance deterioration such as lithium precipitation.