Inhibition of Manganese Dissolution in Mn2O3 Cathode with Controllable Ni2+ Incorporation for High‐Performance Zinc Ion Battery

Abstract Manganese‐based materials are considered potential cathode materials for aqueous zinc ion batteries (ZIBs). However, the dissolution of manganese leading to an abrupt decline of capacity and the sluggish electrochemical reaction kinetics are still the main bottlenecks restricting their further development. Herein, a NiMn‐layered double hydroxide‐derived Ni‐doped Mn 2 O 3 (NM) is developed to suppress the dissolution of manganese. The incorporation of Ni 2+ can promote electronic rearrangement and enhance the conductivity, ultimately improving the reaction kinetics and electrochemical performance of the NM. Moreover, the doped Ni 2+ can effectively stabilize the MnO bond of Mn 2 O 3 by reducing the formation energy. In addition, the storage mechanism based on the simultaneous insertion and transformation of H + and Zn 2+ is demonstrated. Interestingly, the Ni‐doped Mn 2 O 3 shows a high specific capacity of 252 mAh g –1 (0.1 A g –1 ), three times more than the pure Mn 2 O 3 (72 mAh g –1 ). The capacity retention (≈85.6% over 2500 cycles at 1.0 A g –1 ) is also more excellent when comparing with the Mn 2 O 3 cathode (≈49.7%). Significantly, an ultra‐high energy density of 327.6 Wh kg –1 has been achieved using Ni‐doped Mn 2 O 3 cathode, which suggests that the synergistic effect of manganese and other transition metal ions provide a promising strategy for future development of ZIBs.