Spatial Confinement Effect of Mineral‐Based Colloid Electrolyte Enables Stable Interface Reaction for Aqueous Zinc–Manganese Batteries

Abstract

The rational design of inorganic colloid electrolytes enables the manipulation of the solvation structure of Zn2+ ions and addresses zinc dendrite formation and manganese dissolution in aqueous zinc–manganese batteries. In this study, magnesium aluminosilicate (MAS) powder is used to fabricate a mineral‐based colloid electrolyte for Zn//α‐MnO2 batteries. According to theoretical calculations, MAS has a stronger binding energy with Zn2+/Mn2+ ions than with H2O molecules, suggesting the possibility of regulating the solvation structure of Zn2+/Mn2+ ions in a MAS–colloid electrolyte. Based on the experimental results, a high ionic conductivity, wide operating voltage, low activation energy barrier, and stable pH environment is achieved in the MAS–colloid electrolyte. As expected, long‐term cyclic stability can be maintained for 3500 h at 0.2 mA cm−2 in Zn//Zn cells, and high capacities of 255.5 and 239.8 mAh g−1 are retained at 0.2 and 0.5 A g−1 after 100 cycles in Zn//α‐MnO2 batteries, respectively. This performance is attributed to the spatial confinement effect of MAS on the active H2O molecules, which effectively reshapes the solvation structure of Zn2+ ions, guaranteeing reversible zinc deposition, suppressing active manganese dissolution, and ensuring stable interfacial reactions. This work will drive the development of mineral‐based electrolytes in zinc‐based batteries.