A Multifunctional Natural Polymer Protective Layer Enables Improved Anti-Corrosion and Kinetics Performances for Highly Stable Zinc Anode

Abstract

Aqueous zinc-ion batteries (AZIBs) featuring high theoretical capacity, intrinsic safety, and cost-effectiveness are emerging as an ideal candidate for grid-scale energy storage devices. Unfortunately, their practical application is severely impeded by parasitic side reactions and rampant dendrite growth. Herein, a free-standing multifunctional polymer framework based on natural Nicandra physaloides (L.) Gaertn pectin (NPGP) is fabricated by a facile one-step method without additional binders. Theoretical calculations and comprehensive experiments disclose that the 3D continuous skeleton structure and abundant polar groups of the NPGP protective layer synchronously suppress water-mediated side reactions, enhance the interface kinetics, and expedite Zn2+ desolvation. Meanwhile, scanning electrochemical microscopy and small-angle neutron scattering further reveal that the NPGP ensures dendrite-free Zn deposition. Benefiting from the multifunctional synergistic interface regulation, the NPGP-modified Zn anodes deliver an ultra-long cycling lifespan exceeding 5620 h, along with an exceptional average Coulombic efficiency of 99.64% over 1740 cycles. Additionally, the NPGP@Zn||MnO2 full cells achieve a high-capacity retention of 97.46% after 1350 cycles. This work provides feasible and valuable guidance for the design of long-life and high-reversibility AZIBs.