Zinc-dual-halide complexes suppressing polyhalide formation for rechargeable aqueous zinc-halogen batteries

Aqueous zinc-halogen batteries suffer from poor coulombic efficiency and short cycle life owing to the formation and dissolution of polyhalides in electrolytes. Herein, we apply a zinc-dual-halide complex strategy to confine free halides and suppress polyhalide formation. The high stabilities of zinc-dual-halide complexes are identified to be essential for effective confinement. The resulting Zn-Br2 and Zn-I2 cells deliver excellent rate capability and cycling stability, as well as high coulombic efficiency and energy efficiency. A zinc-dual-halide complex strategy is applied in aqueous zinc-halogen batteries, which confines free halides and inhibits polyhalide formation. The resulting Zn-Br2 and Zn-I2 cells realize excellent cycling stability and efficiency.

Automated summary

In this study, a zinc-dual-halide complex strategy is applied to confine free halides and inhibit polyhalide formation in aqueous zinc-halogen batteries, resulting in excellent cycling stability and efficiency.