Robust Biomass Hydrogel Electrolyte via Cytoplasm Reconstruction for Ah‐Level Aqueous Batteries

ABSTRACT Developing sustainable and economic biomass hydrogel electrolyte is highly desired but confronts significant challenges for solid‐state aqueous batteries. Herein, we propose biomass‐cytoplasm reconstruction strategy and develop a type of biomass hydrogel electrolyte with robust mechanical strength of 11.6 MPa, high ion conductivity of 20.27 mS cm −1 , and ultrahigh diffusion coefficient of 1.4 × 10 −5 cm 2 s −1 , where hydrogel electrolyte is fabricated by the facile and energy‐efficiency brining technique. The brining of natural biomass in aqueous electrolytes maintains the self‐supported cytoderm framework but in situ induce polysaccharide/protein cytoplasm reconstruction to acquire ion channels. As a proof of concept, kombu‐based hydrogel electrolyte endows zinc metal batteries with the high current discharge ability of 100 mA cm −2 , the ultra‐wide working temperature from −60°C to 80°C, and the stable cycling‐life of 400 cycles for Ah‐level pouch batteries, as well as the practical verification of the integrated photovoltaic‐battery energy storage systems. Biomass‐cytoplasm reconstruction concept is also demonstrated by aluminum metal batteries to verify the universality, and endow biomass hydrogel electrolyte with threefold cost reductions and notable sustainability advantages compared with petroleum‐based hydrogel electrolyte. This work not only provides a new prototype to design high‐performance hydrogel electrolyte for aqueous batteries but also realizes green and sustainable development.