Preparation of high performance MnO2 cathode for lithium primary battery through uniform particle size and crystal modulation

• Published in: Journal of power sources Vol. 633; p. 236368
• Main Authors: Tang, Chenwei, Gao, Yinyi, Zhu, Kai, Cao, Dianxue
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.03.2025
• Subjects: Crystal modulation; High-rate discharge; Lithium primary batteries; MnO2 cathodes; Lithium primary batteries; High-rate discharge; Crystal modulation; MnO2 cathodes
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2025.236368

Commercial electrolytic manganese dioxide (EMD) is a widely applicable cathode material in lithium primary batteries (LPBs). Nevertheless, the EMD is limited by several key issues in practical use, which are mainly low electronic conductivity and slow diffusion kinetics. A particle size and crystal type modulation strategy were used to improve the electronic conductivity and ion diffusion kinetics of EMD for the first time. EMD treated with sand milling has a smaller and narrower particle size distribution, which improves reaction kinetics. As analyzed by Rietveld structure refinement, the heat treatment at different temperatures resulted in different degrees of phase transition from γ-MnO2 to β-MnO2 in EMD. The β-MnO2 improved the electrical conductivity of EMD, and the crystal structure defects caused by mixing γ-MnO2 with β-MnO2 provided more electrochemical reaction sites. Electrochemical tests demonstrated that the heat-treated EMD after sand milling (SEMD-T) exhibited enhanced electrochemical properties. In particular, the specific capacity of SEMD-380 is 245.7 mAh g−1 at 0.1 C, which reached 79.8 % of theoretical specific capacity. The maximum energy density of SEMD-380 at 5 C (332.50 Wh kg−1) exceeds that of EMD by a factor of three. These findings offer effective guidance for designing high performance electrodes in the future. •Improving electrode reaction kinetics of MnO2 by particle size control.•Improving the electrical conductivity of MnO2 by crystal modulation.•The cell parameters and phase occupancies in MnO2 were analyzed by Rietveld refinement.•The performance of LPBs based on SEMD-380 cathode was greatly improved.