Research of MnCO₃/CB Composite on Properties Apply to Supercapacitors

China Automotive Technology and Research Center Co., Ltd, 300300 Tianjin, China

^* Corresponding author: hanliqiong@catarc.ac.cn

Abstract

In order to improve the electro-conductibility of new energy storage material-manganese carbonate(MnCO₃) and the properties apply to supercapacitors, we produce MnCO₃/CB composite at room temperature by using a simple and mild liquid phase deposition method. Using dilute HNO₃ to purify and activate the CB(carbon black), then put the handled CB into NH₄HCO₃/MnSO₄ mixed solution for liquid deposition. Observed through infrared and XPS methods, we found that - after purified by dilute HNO₃, the negatively charged groups(carboxyl & quinonyl) on CB surface increase, which makes CB uneasy to reunite in water and benefits the producing of a homogeneous compound. Observed the compound under SEM:40nm diameter CB granules wrap the Lotus-shaped MnCO₃ granule, and form a porous structure between MnCO₃ granules. The result of electro-chemical properties indicated by galvanostatic charge-discharge tests shows that the specific capacity of MnCO₃/CB composite electrode material is twice of the pure MnCO₃ electrode material, while the MnCO₃/CB composite has a good cycle capacitive retention ratio. As a newly discovered energy storage material, MnCO₃ provides a new direction to make composite material for supercapacitor electrodes.