Improvement of rechargeability of solid-state alkaline Zn-MnO2 battery with Bi2O3 doped cathode

Rechargeability improvement Zn-MnO₂ battery is crucial to the further development and wide application of this battery. This work demonstrated, conventional Bi₂O₃ doping by physical method into γ-MnO₂ as a cathode, PVA-KOH alkaline gel polymer electrolyte (GPE) as an electrolyte, and zinc powder as an anode. The assembled solid-state Zn|GPE|MnO₂-Bi₂O₃ cell presents certain rechargeability, at the 77% discharge depth of MnO₂ one-electron discharge capacity and a cut-off voltage of 0.7V. Discharge capacity kept over 55% of the first discharge capacity even at the 20^th cycle. The improvement of rechargeability is attributed to the enhancement of electrochemical reversibility of MnO₂ modified by Bi₂O₃.