Gradient Desolvation–Diffusion Kinetic Layer Promoters for Low-Temperature Dendrite-Free Zn Metal Batteries

Aqueous zinc metal batteries have emerged as strong candidates for large-scale energy applications, but they are inhibited by significant dendrite growth resulting from corresponding depressive desolvation–diffusion kinetics. Herein, the strategy of gradient desolvation–diffusion kinetics is proposed by constructing an organic–inorganic layer on the zinc anode for increasing robust mechanical properties and strengthening ion/atom transport. The electron-insulative polymer layer effectively prevents interfacial electron contact from side reactions, and the phase-transformed Sn and ZnF2 layer also promotes Zn2+ transport with lower barrier, as demonstrated by electrochemical and theoretical simulations. Consequently, the fabricated symmetric cell exhibits a surprisingly long-term life of 4000 h with low overpotentials (17 mV) and high average Coulombic efficiency under low-temperature surroundings. Coupled with MnO2 and V2O5 cathodes, the full cells also show high-capacity retentions under a high rate of 3 A g–1 or low-temperature surroundings, indicating the promising prospect of fast desolvation–diffusion modulation for practical applications.