The synthesis of β-MnO2 nanorods as cathode and the effect and mechanism of graphene composite on the performance of Li–MnO2 primary battery

Abstract

A facile method to synthesize β-MnO₂ micro-particles under low temperature without templates or catalysts was reported in the study. The products were characterized by power X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrum (FTIR), AC impedance, and cyclic voltammetry measurement (CV). Compared to the commercial Xiangtan electrolytic manganese dioxide (XT-EMD, China), the prepared β-MnO₂ had better crystallinity and nanorod structure, and higher rate performance. The prepared β-MnO₂ and the commercial XT-EMD were used as cathode active materials, respectively, and assembled into CR2032 batteries for discharge performance characterization. The AC impedance analysis of the battery shows that the diffusion coefficient of lithium ions on prepared β-MnO₂ cathode is 29.73% higher than that of XT-EMD cathode. The service life of the prepared β-MnO₂ as cathode was 5.14%, 8.01%, 6.48%, and 11.23% higher than those of the commercial XT-EMD with high-temperature treatment at 15, 8.25, 3, and 1 kΩ constant load discharge, respectively, showing the good rate performance of the prepared β-MnO₂ as cathode active material of Li–MnO₂ battery. At the same time, a small amount of multilayer graphene was doped in cathode, which was benefit for the third-stage discharge performance of the Li–MnO₂ primary battery. And the glass fiber separator was more suitable for the separator of the Li–MnO₂ primary battery and improved the discharge performance of the second stage of discharge.