Reducing Water Activity by Zeolite Molecular Sieve Membrane for Long‐Life Rechargeable Zinc Battery

Abstract

Aqueous electrolytes offer major advantages in safe battery operation, green economy, and low production cost for advanced battery technology. However, strong water activity in aqueous electrolytes provokes a hydrogen evolution reaction and parasitic passivation on electrodes, leaving poor ion-transport in the electrolyte/electrode interface. Herein, a zeolite molecular sieve-modified (zeolite-modified) aqueous electrolyte is proposed to reduce water activity and its side-reaction. First, Raman spectroscopy reveals a highly aggressive solvation configuration and significantly suppressed water activity toward single water molecule. Then less hydrogen evolution and anti-corrosion ability of zeolite-modified electrolyte by simulation and electrochemical characterizations are identified. Consequently, a zinc (Zn) anode involves less side-reaction, and develops into a compact deposition morphology, as proved by space-resolution characterizations. Moreover, zeolite-modified electrolyte favors cyclic life of symmetric Zn||Zn cells to 4765 h at 0.8 mA cm^-2 , zinc-VO₂ coin cell to 3000 cycles, and pouch cell to 100 cycles. Finally, the mature production technique and low-cost of zeolite molecular sieve would tremendously favor the future scale-up application in engineering aspect.