Bio-inspired biomass hydrogel interface with ion-selective responsive sieving mechanism for corrosion-resistant and dendrite-free zinc-iodine batteries

Abstract

Aqueous zinc-iodine (Zn-I₂) batteries are considered a promising contender for grid energy storage, but their practical application is hindered by such problems as the grievous polyiodide shuttle, parasitic corrosion and Zn dendrite growth. Herein, an immune cell-inspired biomass hydrogel interfacial layer composed of carboxymethyl chitosan/sodium alginate (CCS/SA) is constructed on the Zn anode by an in-situ gelation strategy, which exhibits the enhanced cycling stability of Zn-I₂ batteries. The multifunctional CCS/SA hydrogel interface with a unique ion-selective responsive sieving mechanism acts as a pre-interception layer to block polyiodide ions but favors Zn²⁺ ion transfer and nucleation behavior. Furthermore, the hydrogen bond networks of water are perturbed with the CCS/SA layer, thereby restraining the activity of water molecules and alleviating the detrimental Zn corrosion. As a result, the Zn-I₂ battery with a CCS/SA-Zn anode achieves an ultra-long cycle life of 60,000 cycles at 5 A g⁻¹, superior to bare Zn-based cells and the state-of-the-art batteries ever reported. This work demonstrates the important role of the bio-inspired multifunctional biomass hydrogel interface developed for zinc-ion batteries and provides in-depth insight into the engineering strategy to promote the actual application of Zn-I₂ batteries.