In this work, we used the mixed solution of manganese acetate and sodium sulfate to deposit manganese dioxide on the three-dimensional porous nickel foam that was previously soaked in alcohol, and then the effects of solution concentrations on their capacitance properties were investigated. The surface morphology, microstructure, elemental valence and other information of the material were observed by scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray photoelectron spectroscopy (XPS), etc. The electrochemical properties of the material were tested by Galvanostatic charge-discharge (GCD), Cyclic Voltammetry (CV), Chronoamperometry (CA), Electrochemical impedance spectroscopy (EIS), etc. The MnO₂ electrode prepared at lower concentrations can respectively reach a specific capacitance of 529.5 F g⁻¹ and 237.3 F g⁻¹ at the current density of 1 A g⁻¹ and 10 A g⁻¹, and after 2000 cycles, the capacity retention rate was still 79.8% of the initial capacitance, and the energy density can even reach 59.4 Wh Kg⁻¹, while at the same time, it also has a lower electrochemical impedance (Rs = 1.18 Ω, Rct = 0.84 Ω).

Aqueous zinc-ion batteries (AZIBs) are promising for grid-scale storage due to their safety, low cost, and environmental benignity. However, water-dipole enrichment in the inner Helmholtz plane (IHP) of Zn anodes triggers hydrogen evolution, corrosion, and dendrites, limiting cycle life. We report a trace “ionic liquid–polar solvent coupling” strategy: adding only 0.01 M EMIMBF₄ and 0.03 M DMSO to 2 M ZnSO₄ electrolyte. Hydrophobic EMIM⁺ adsorbs on the IHP to expel interfacial water, while BF₄⁻ enters the primary solvation shell and DMSO penetrates both first and second shells of Zn²⁺, forming a water-deficient coordination environment. This interfacial–solvation synergy suppresses parasitic reactions and directs preferentially oriented Zn deposition exclusively along the (101) facet, enabling dense vertical plating and in situ formation of a compact, inorganic-rich SEI (ZnCO₃–ZnSO₃–Zn(OH)₂). Consequently, Zn||Zn cells cycle stably for >5362 h at 1 mA cm⁻²/1 mAh cm⁻²; Zn||Cu cells achieve 1300 cycles with 99.8% average Coulombic efficiency; and Zn||V₂O₅ full cells retain 326.4 mAh g⁻¹ after 500 cycles. This work shows that minimal additive loading can simultaneously engineer the electrode–electrolyte interface and crystallographic deposition pathway, offering a simple yet robust design for ultra-stable AZIBs.