SECONDARY BATTERY AND DEVICE COMPRISING SECONDARY BATTERY

This application provides a secondary battery and a device comprising the same. The secondary battery includes a negative electrode plate and an electrolyte. The negative electrode plate includes a negative electrode active material. The electrolyte includes an electrolyte salt, an organic solvent, and an additive. The negative electrode active material includes a silicon-based material. [0002] The organic solvent includes ethylene carbonate (EC) and diethyl carbonate (DEC). A mass ratio of EC in the organic solvent is less than or equal to 20%, and a mass ratio of DEC in the organic solvent is less than or equal to 20%. The additive includes an additive A and an additive B. The additive A is selected from one or more of compounds represented by Formula 1 or Formula 2, and the additive B is selected from one or more of compounds represented by Formula 3. The secondary battery and the device comprising the same according to this application achieve good high-temperature cycle performance, good high-temperature storage performance, and a low direct-current internal resistance while keeping a high energy density at the same time.