Zincophilic polymer nanofiber network as multifunctional interface layer to stabilize Zn metal anodes

Uncontrollable parasitic reactions and excessive dendrite growth on Zn anodes usually cause the rapid cycling deterioration of aqueous zinc ion batteries (AZIBs). Herein, we constructed a three-dimensional (3D) crosslinked polyamic acid (PAA) nanofiber network serving as a multifunctional interface layer to stabilize the Zn metal anode. The zincophilic PAA interface layer can regulate Zn 2+ flux and enhance zinc ions transport kinetics, ensuring the uniform Zn deposition with dendrite-free morphology. Furthermore, the PAA interface layer can effectively suppress the hydrogen evolution reaction and the formation of byproducts, thereby achieving highly reversible Zn plating/stripping. As a result, the Zn@PAA anode exhibits a higher Zn 2+ transference number and a lower Zn nucleation overpotential compared with bare Zn. The Zn@PAA symmetrical cell obtains a cycling lifespan exceeding 2000 h at 1 mA cm −2 , 1 mAh cm −2 and maintains a stable operation for 1300 h (2 mA cm −2 , 2 mAh cm −2 ) and 700 h (10 mA cm −2 , 1 mAh cm −2 ). Besides, the full cell based on Zn@PAA anode delivers an average specific capacity of 303.2 mAh g −1 at 0.5 A g −1 and acquires an 87.1 % capacity retention rate after 800 cycles, demonstrating a superior modification effect of zincophilic PAA as the protective layer. • Designing a multifunctional PAA interface layer to protect Zn anode. • PAA interface layer possesses zincophilic peculiarity and high Zn 2+ transference rate. • Zn@PAA anode presents mitigated dendrite growth and side reactions. • Zn@PAA anode shows high performance for aqueous zinc ion batteries.