Study on the Electrochemical Properties of Mg1−xYxCO3@2MnCO3 Doped at Magnesium Site and the Effect of Manganese Carbonate and Magnesium Carbonate Composite Material Modified by Zn Doping

Abstract

Mangan-based zinc ion batteries have received increasing attention due to their high theoretical capacity and environmental friendly properties. However, the capacity attenuation of manganese-based materials during the charge-discharge cycle seriously affects the improvement of electrochemical performance. In order to solve the problem of capacity attenuation, magnesium carbonate material was combined with manganese carbonate material, and the magnesium site was doped and modified. In this paper, the Mg0.98Zn0.02CO3@2MnCO3 material was selected out from all the synthesized materials due to its stable electrochemical performance, its capacity is as high as 283.65 mAh g−1 under the current density of 100 mA g−1. Subsequently, the characterization test was carried out to further discover the composition of the material. It can be observed from SEM that the material has two main structures: cube shape and spheroid shape, and nanowires grow on the surface of the cube structure. Moreover, the EDS and XPS tests were conducted which could prove the elements contained in Mg0.98Zn0.02CO3@2MnCO3 material were consistent with the valence states of the elements in manganese carbonate and magnesium carbonate. The further infrared and Raman tests showed that the functional groups in the material were also consistent with the molecular formula. According to the XRD test result, no obvious impurity peak can be oberved, indicating the electrochemical performance of Mg0.98Zn0.02CO3@2MnCO3 composite material synthesized by hydrothermal method is relatively stable.