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

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 cm² 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.