Promoting Proton Migration Kinetics by Ni<sup>2+</sup> Regulating Enables Improved Aqueous Zn‐MnO<sub>2</sub> Batteries
Jie Ji, Jia Yao, Yongchang Xu, Houzhao Wan, Bao Zhang, Lin Lv, Jingying Li, Nengze Wang, Zhaohan Zheng, Jun Zhang, Guokun Ma, Tao Li, Hanbin Wang, Yi Wang, Hao Wang, Hao Wang, Hao Wang
Abstract
The energy storage behaviors of MnO 2 for aqueous Zn‐MnO 2 batteries mainly depend on the Zn 2+ /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 Ni 2+ into γ‐MnO 2 (Ni‐MnO 2 ). Ni 2+ can lower the diffusion barrier of H + and selectively induce the ion intercalation, thereby alleviating the electrostatic interaction with the lattice. Moreover, Ni 2+ enables the adjacent [MnO 6 ] octahedrons to have better electron conductivity. The Ni‐MnO 2 exhibits superior rate performance (nearly four times specific capacity compared with MnO 2 ) 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‐MnO 2 allows H + migrate rapidly along the one‐dimensional tunnel due to reduction of the activation energy caused by Ni 2+ regulating, thus achieving excellent reaction kinetics. This work brings great potential for the development of high‐performance aqueous Zn‐MnO 2 batteries.