Integration of confinement crosslinking and in situ grafting for constructing artificial interphases toward stabilized zinc anodes

Abstract

The Zn anode is susceptible to intractable Zn dendrites and interfacial side reactions, thereby hindering the practical implementation of aqueous zinc ion batteries (AZIBs). Promoting the heterogeneous compatibility and interfacial stability of artificial solid electrolyte interfaces (SEIs) to effectively achieve highly stable and reversible Zn anodes is thus strongly desired. Herein, a novel integration of confinement crosslinking and in situ grafting strategy is employed to enhance the heterogeneous compatibility and interfacial stability of the artificial composite SEI. Through the confinement crosslinking of carrageenan on Zn-SSZ13 molecular sieves, the –OSO₃⁻ groups of carrageenan can be confined to the surface of hollow Zn-SSZ13 nanoparticles at the carrageenan/Zn-SSZ13 interface while the –OH moieties can function as Zn²⁺ transport sites, thereby boosting the heterogeneous compatibility. The carrageenan molecule and the Zn-SSZ13 particle can both be in situ grafted at the SEI/Zn foil interface, effectively promoting interfacial stability. Noticeably, this artificial SEI successfully inherits the dual functionalities of inducing uniform Zn deposition via the carrageenan molecules and suppressing water reactivity by the hollow Zn-SSZ13 nanoparticles. As a result, the optimal electrode coated with this SEI (ZC-8-2-50@Zn) exhibits effective inhibition of side reactions. Symmetrical cells assembled with the ZC-8-2-50@Zn electrodes can achieve a cycling lifespan exceeding 1200 h at 10 mA cm⁻² and 1 mA h cm⁻². Furthermore, they even demonstrate an impressive cumulative plating capacity of 10 375 mA h cm⁻² at 25 mA cm⁻² and 10 mA h cm⁻². The ZC-8-2-50@Zn‖MnO₂ full cell and ZC-8-2-50@Zn‖Na₂V₆O₁₆·1.5H₂O (NVO) pouch cell can achieve a capacity retention of approximately 76.3% after 600 cycles and 90.3% after 100 cycles. This strategy provides a feasible approach to enhance the stability of zinc anodes.