Sodium secondary battery, battery module, battery pack, and electric device

• Main Authors: GUO BINGKUN, LI XIAOLONG, LIU BEN, YAO SHIKANG, CHEN SHIGANG, ZHANG XINXIN
• Format: Patent
• Language: Chinese; English
• Published: 16.07.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention provides a sodium secondary battery, a battery module, a battery pack and an electric device. The sodium secondary battery comprises a positive pole piece, a negative pole piece, a first electrolyte located on the side of the positive pole piece and a second electrolyte located on the side of the negative pole piece, the first electrolyte and the second electrolyte contain different organic solvents, the first electrolyte contains an ester solvent, a sulfone solvent or a fluoroether solvent, and the second electrolyte contains an ester solvent, a sulfone solvent or a fluoroether solvent. And the second electrolyte contains an ether solvent or an amide solvent. Different organic solvents are respectively matched with the positive/negative pole pieces, so that the gas generation expansion of the battery is reduced, the electrochemical stability window width of the battery is optimized, the cycle stability of the battery is improved, and the comprehensive performance of the battery is further impro