Synergistic Enhancement of Mn²⁺ Doping and Thermal Field Treatment on Cs₂NaBiCl₆ Double Perovskite Anode Performance for Lithium-Ion Batteries

Perovskite materials are widely used as multifunctional materials in photovoltaics, electronics, and electrochemistry and have been explored for use in the field of lithium-ion battery research in recent years due to their excellent ion mobility properties and defect tolerance. Cs2NaBiCl6, with excellent ion mobility properties and defect tolerance, is explored for use as an anode in lithium-ion batteries, which have higher initial capacity and the potential for combining with halide solid electrolytes; however, low cycling stability limits its application. In this paper, Mn2+-doped Cs2NaBiCl6 powders were successfully prepared via the solvothermal method, and Mn2+ was used as an anchor to stabilize the perovskite lattice to improve its electrochemical performance. Meanwhile, the cycling stability can also be enhanced by the thermal field treatment. Finally, the discharge specific capacity of the cell was increased from 81 mA h/g to nearly 240 mA h/g under the synergistic effect of the dopant and the thermal field, and the capacity retention of the cell was close to 100% in the subsequent electrochemical cycles. This capacity enhancement provides a feasible strategy to improve the performance of perovskite anode materials.