Ultra-long cycle sodium ion batteries enabled by the glutaric anhydride additive.

For sodium-ion batteries, solving the issue of short cycle life is key to their large-scale adoption in the industry, and the electrolyte plays an important role on this. Herein, this work aims to design a practical sodium ion battery electrolyte with industrial application value and introduces anhydride compounds as additives for the first time. Meanwhile, by adjusting the solvent composition and using a combination of ether and ester solvents, the optimal electrolyte formulation of 1 M NaPF (sodium hexafluorophosphate) + DME (glycol dimethyl ether)/VC (vinylidene carbonate) (1 : 1, v/v) + 2 wt% GA (glutaric anhydride) is designed.