Aqueous Alcl3/Zncl2 Solution Room-Induced the Self-Growing Strategy of Expanded Topological Network for Cellulose/Polyacrylamide Solid-State Electrolytes

Abstract

The green synthesis strategy for cellulose-containing hydrogel electrolytes is of great significance in the contemporary world for effectively managing resources, energy, and environmental concerns. Herein, we propose an all-green strategy using AlCl3/ZnCl2/H2O cellulose solvent to create cellulose/polyacrylamide hydrogel electrolytes (AZ-Cel/PAM) with expanded hierarchical topologies. The AlCl3/ZnCl2 aqueous solution facilitates the efficient dissolution of cellulose at room temperature, and the dispersed Al3+-Zn2+ autocatalytic system catalyzes in-situ polymerization of AM monomer. This allows the AM network to expand within the cellulose framework, forming multiple bonding interactions and stable ion channels. The resulting hybrid hydrogel exhibits improved mechanical properties (compressive strength of 359.43 kPa) and enhanced ionic conductivity (1.99 S/m). Moreover, it also demonstrates excellent adhesion, freeze resistance (-45 °C), and water retention capabilities. Quantum mechanical simulations further clarify the mechanical composition and ion transport mechanism of AZ-Cel/PAM hydrogels. The supercapacitor assembled using the hydrogel electrolyte demonstrates an ideal area-specific capacitance of 203.8 mF·cm-2. This all-green strategy presents a new approach for developing sustainable green energy storage devices.

Keywords: All-green strategy, Cellulose-containing hydrogel electrolyte, AlCl3/ZnCl2 aqueous solution, Polyacrylamide, Hierarchical expanded topology