Stabilizing α-MnO Tunnel Structure via Mo-Zn Synergistic Doping for Highly Efficient Zn Storage.

To address the rising demand for eco-friendly and efficient energy storage devices, rechargeable aqueous zinc ion batteries (AZIBs) are emerging as a promising candidate for large-scale energy storage. α-MnO has attracted extensive attention for its open channels and exceptional Zn storage capacity. However, the electrochemical performance of α-MnO is significantly hindered by severe structural collapse and sluggish reaction kinetics. Herein, we propose a simple hydrothermal approach for co-doping Mo and Zn into tunnel-structured MnO (MZMO). The ion diffusion kinetics of MZMO are optimized due to ameliorated electrical conductivity by doped cations and introduced oxygen vacancies within the MnO lattice. Moreover, Mo and Zn co-doping stabilizes the MnO framework, significantly enhancing its electrochemical performance during prolonged cycling. Charge storage mechanism analysis further validates the extraordinary stability of the MZMO phase structure during the Zn/H co-intercalation and deintercalation. The MZMO cathode demonstrates rapid and reversible Zn storage, with a high capacity of 395 mAh g at 0.2 A g, and the capacity remains at 136 mAh g after 1000 cycles at 2 A g. This study demonstrates Mo and Zn co-doping is an effective strategy to enhance the electrochemical performance of MnO, offering valuable insights for developing other promising cathodes for AZIBs.