▎ 摘　　要

NOVELTY - Sodium ion battery comprises anode, cathode and nonaqueous electrolytic solution. The cathode includes cathode material layer containing cathode active material. The non-aqueous electrolytic solution comprises non-aqueous organic solvent and sodium salt which include sodium bis(fluorosulfonyl)imide. USE - Used as sodium ion battery. ADVANTAGE - The sodium ion battery has excellent low-temperature performance, and realizes the performance advantages of high rate and long cycle operation. DETAILED DESCRIPTION - Sodium ion battery comprises anode, cathode and nonaqueous electrolytic solution. The cathode includes cathode material layer containing a cathode active material. The non-aqueous electrolytic solution comprises non-aqueous organic solvent and sodium salt which include sodium bis(fluorosulfonyl)imide. The sodium ion battery meets the conditions of x*y/z is 4.5-0.5 and x is 1.20-1.05, y is 2-12, and z is 1-12. Where x is the N/P ratio of the sodium-ion battery, y is the median particle size of the cathode active material, in μm, and z is the mass percentage of sodium bis(fluorosulfonyl)imide in the non-aqueous electrolyte, in %.