Regulating the interface chemistry of separator to normalize zinc deposition for long lifespan Zn batteries

Despite the prospect of zinc-ion batteries for stationary energy storage, the rampant dendrite generation on the Zn anodes significantly downgrades the cycling lifespan. Herein, an in situ design strategy of implanting g-C3N4 onto individual glass fibers is proposed to regulate the interfacial chemistry of commercial separator toward planar and dense deposition of Zn. The negative nitrogen species could afford abundant zincophilic centers as an ion redistributor for normalizing Zn2+ ion flux with enhanced transference number (0.64) and conductivity (5.79 mS cm−1). The as-modified composite separator enables remarkable decrease of Zn nucleation and growth overpotentials and thus achieves fast and dendrite-free plating/stripping kinetics. Impressively, the unique separator engineering endows the zinc anode with a prolonged operating lifetime over 800 h under a high current of 10 mA cm−2 and a superior cycling endurance in Zn-MnO2 full batteries. The design tactic of separator could pave a facile yet effective pathway for mitigating the prevailing challenges of rechargeable metal anodes beyond zinc.