Synthesis and Electrochemical Properties Investigation of MnO2 Materials Derived from Manganese Salts for Cathode Applications in Zinc-Ion Batteries via the Hydrothermal Method

Manganese dioxide (MnO2) has recently attracted significant attention as a cathode material for zinc-ion batteries (ZIBs) due to its outstanding advantages, including environmental friendliness, non-toxicity, and high specific capacity. However, commercially available Mn O2 typically exhibits large and irregular particle sizes, which adversely affect its electrochemical performance. In this study, Mn O2 was synthesized from manganese precursors, including MnCl2, Mn(CH3COO)2, and MnSO4, via a hydrothermal method to optimize the synthesis process and obtain Mn O2 with uniform, nanoscale particle size suitable for aqueous pouch-type Zn-ion batteries. Among the synthesized materials, Mn O2 derived from MnCl2 exhibited superior electrochemical properties, achieving a charge/discharge efficiency of over 95% and a high specific capacity of approximately 200 mAh/g at a current rate of 0.6C.