Promoting Proton Migration Kinetics by Ni2+ Regulating Enables Improved Aqueous Zn‐MnO2 Batteries

The energy storage behaviors of MnO2 for aqueous Zn‐MnO2 batteries mainly depend on the Zn2+/H+ intercalation but are limited by poor ion/electron migration dynamics and stability. Herein, a strategy is proposed that promoting proton migration kinetics ameliorates H+ storage activity by introducing Ni2+ into γ‐MnO2 (Ni‐MnO2). Ni2+ can lower the diffusion barrier of H+ and selectively induce the ion intercalation, thereby alleviating the electrostatic interaction with the lattice. Moreover, Ni2+ enables the adjacent [MnO6] octahedrons to have better electron conductivity. The Ni‐MnO2 exhibits superior rate performance (nearly four times specific capacity compared with MnO2) and ultra‐long‐cycle stability (100% of capacity retention after 11 000 cycles at 3.0 A g−1). The calculation indicates that the Ni‐MnO2 allows H+ migrate rapidly along the one‐dimensional tunnel due to reduction of the activation energy caused by Ni2+ regulating, thus achieving excellent reaction kinetics. This work brings great potential for the development of high‐performance aqueous Zn‐MnO2 batteries. Ni2+‐doped MnO2 is successfully synthesized for aqueous ZIBs. The introduction of Ni2+ can effectively regulate the H+ storage behavior and endow the Ni‐MnO2 electrode material with excellent proton migration kinetics. Meanwhile, Ni2+ could lower the diffusion barrier of H+ and selectively induce the ion intercalation. Density functional theory clearly reveals that Ni2+ doping significantly ameliorates structural stability and enhances conductivity of electrons.