Highly reversible Zn anodes enabled by in-situ construction of zincophilic zinc polyacrylate interphase for aqueous Zn-ion batteries.

The irreversibility and low utilization of Zn anode stemming from the corrosion and dendrite growth have largely limited the commercialization of aqueous zinc batteries. Here, a carbonyl-rich polymer interphase of zinc polyacrylate (ZPAA) is spontaneously in-situ constructed on Zn anode to address the above-mentioned dilemmas. The ZPAA interlayer enables fast transport kinetics of Zn and tailors the interfacial electric field for realizing the uniform Zn deposition due to superior zincophilicity, high Zn transference number and inherent ion-diffusion channel. Importantly, acting as a buffer interphase with strong adhesion and isolation of electrolytes, this functional layer effectively protects the Zn electrode against the water-induced erosion and passivation. Remarkably, the ZPAA@Zn electrode realizes an enhanced Coulombic efficiency of 99.71 % within 2200 cycles, delivers an ultra-long cycling stability over 7660 h (>319 days, 1 mA cm) and 2460 h (5 mA cm) with lower voltage hysteresis. Also, the ZPAA@Zn/MnO full cell maintains a high capacity of 114 mAh/g after 2000 cycles, much better that of untreated Zn/MnO cell (25 mAh/g). This concept of in-situ fabricating ion-sieve-like polymer interphase provides a facile approach to stabilize Zn anode and further paves a way for high-performance aqueous batteries.