Research of MnCO3/CB Composite on Properties Apply to Supercapacitors

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 NH4 HCO3 /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.