Electrolyte Decoupling Strategy for Metal Oxide‐Based Zinc‐ion Batteries Free of Crosstalk Effect

The crosstalk of transition metal ions between the metal oxide cathode and Zn anode restricts the practical applications of aqueous zinc‐ion batteries (ZIBs). Herein, we propose a decoupled electrolyte (DCE) consisting of a nonaqueous‐phase (N‐phase) anolyte and an aqueous‐phase (A‐phase) catholyte to prevent the crosstalk of Mn2+, thus extending the lifespan of MnO2‐based ZIBs. Experimental measurements and theoretical modelling verify that trimethyl phosphate (TMP) not only synergistically works with NH4Cl in the N‐phase anolyte to enable fast Zn2+ conduction while block Mn2+ diffusion toward anode, but also modifies the Zn2+ solvation structure to suppress the dendrite formation and corrosion on Zn anode. Meanwhile, the A‐phase catholyte effectively accelerates the cathode reaction kinetics. The as‐developed Zn|DCE|MnO2 cell delivers 80.13% capacity retention after 900 cycles at 0.5 A g‐1. This approach is applicable for other metal oxide cathode‐based ZIBs, thereby opening a new avenue for developing ultrastable ZIBs.