Topological chitosan framework enables reversible columnar array anodes for high-performance aqueous zinc batteries

Eco-friendly aqueous zinc batteries can replace lead-acid batteries in scenarios that balance safety and energy density. However, the synergistic deterioration between structural collapse and kinetic failure of zinc anodes at high discharge depth and high current densities restricts the actual energy and power densities. Herein, we propose a strategy for the in situ integration of double-layer topological chitosan framework (D-CTS) on current collectors by regulating phase separation kinetics during multistage coordination-neutralization electrophoresis. The vertical through-hole array is formed by the coupling of instantaneous and delayed phase separation. Then, the columnar zinc array is mediated by D-CTS to construct the integrated component (D-CTS-Zn) of a vertical through-hole separator and array anode. The embedded interconnected nanonetworks within the through-hole wall enable the dynamic equilibrium of the columnar zinc array by a lateral ion compensation mechanism. As a result, the Zn||Zn symmetric cell with D-CTS-Zn stably cycles over 3000 cycles at 200 mA cm−2 under 60% discharge depth. The assembled D-CTS-Zn||MnO2 battery delivers an energy density of 83 Wh kg−1 at an ultrahigh power density of 9.25 kW kg−1. This work provides a constructive strategy for chitosan phase separation regulation and separator-induced reversible metal array anodes.