Improving Zn2+ migration via designing multiple zincophilic polymer electrolyte for advanced aqueous zinc ion batteries

Abstract

A multiple zincophilic primitives-based polymer electrolyte is developed to solve limited ionic transport kinetic at the bulk of polymer-based electrolyte and interface of aqueous zinc ion batteries , resulting in a significant increase in battery cycle life. • A single network polymer electrolyte with multiple zincophilic primitives is first reported. • The multiple coordination mechanism greatly facilitates the desolvation of the solvated zinc ions. • The zincophilic groups facilitate the tight adhesion of the polymer to the zinc anode. • The zincophilic groups induce the uniform deposition of Zn 2+ on the surface of the zinc anode. • The polymer electrolyte significantly extends the cycle life of batteries. Aqueous zinc ion batteries (AZIBs)-based on Zn metal anode face serious issues of hydrogen evolution, corrosion, and zinc dendrite growth, limiting their practical applications. Polymer-based electrolytes can effectively inhibit the above issue, but usually bring additional interfacial resistance, resulting in slow reaction kinetics. Herein, we report a poly(4-acryloylmorpholine) electrolyte with multiple zincophilic primitives for fast zinc ion transport at bulk and interface of Zn metal anode (zinc ion transfer number of 0.77) via a facile one-pot polymerization. The special electrolyte structure with multiple zincophilic primitives can adhere tightly to the Zn metal anode and induce uniform Zn deposition, resulting in low interface resistance and enhanced cycling life of batteries. Therefore, the symmetric Zn||Zn batteries assembled based on the designed and synthesized polymer electrolyte can be stably cycled for 1400 with low overpotential (∼220 mV) at 0.5 mA cm −2 with a capacity of 0.5 mAh cm −2 , and the corresponding V 2 O 5 ||Zn full batteries exhibit attractive reversibility, rate performance, and cycling stability. The electrolyte engineering in this work paves a new path for the construction of polymer-based electrolytes for safe and stable AZIBs.