Towards practical aqueous zinc metal pouch cell batteries via weakly bound water-mediated shear-thickening electrolyte

Disordered dendrite growth and corrosion reactions of zinc negative electrodes remain critical challenges in aqueous zinc metal batteries. Regulating water states in shear-thickening non-Newtonian fluid electrolytes has emerged as a promising strategy to simultaneously suppress dendrite growth and corrosion for zinc negative electrodes. Herein, we design a multifunctional shear-thickening non-Newtonian fluid electrolyte, based on carboxymethyl cellulose and sulfonate silicon oxide nanoparticles, which addresses both issues through hierarchical regulation of water molecule states. Carboxymethyl cellulose converts free water into weakly bound water, thereby suppressing water-induced parasitic reactions. Concurrently, sulfonated SiO₂ nanoparticles form an integrated shear-thickening network with amylopectin and carboxymethyl cellulose while introducing abundant surface –SO₃⁻ groups that disrupt the strongly bound water layer at the zinc interface. This architecture enables localized mechanical stiffening at dendrite tips without compromising ionic conductivity. As a result, Zn | |Zn symmetric cells exhibit stable Zn plating/stripping for 900 h at 50 mA cm⁻² and 25 mAh cm⁻², and Zn | |I₂ pouch cells with a capacity of 1.5 Ah maintain stability over 200 cycles at 20 mA cm⁻². These findings offer a alternative pathway toward corrosion-resistant, mechanically adaptive aqueous and practical zinc pouch cells systems.