炭载二氧化锰的制备和锂离子超级电容器性能的研究

Preparation of Carbon Supported Manganese Dioxide and Its Application for Lithium Ion Supercapacitor

制备了炭气凝胶载二氧化锰(AG-MnO2)复合材料,材料物理化学表征表明,在炭气凝胶表面和微孔内沉积二氧化锰,改善了炭气凝胶的电化学性能.以炭二氧化锰复合材料为负极,LiMn2O4为正极,设计出一种新型的高能量密度混合电容器,并研究了负极工作电位范围对电容器性能的影响.研究结果表明,引入高容量的AG-MnO2复合材料,并通过扩大负极工作电位区间,可设计出能量密度高达92Wh·kg-1(基于正负极活性质量)的混合电容器,为炭对称电容器的5倍.这种混合电容器经过1000次循环,容量仍然保持在80%以上.

A new electrode material, carbon aerogel supported manganese dioxide （AG-MnO2） has been prepared. Psychochemical and electrochemical characterizations indicated that the electrochemical performance of carbon aerogel can be dramatically improved only through depositing manganese dioxide on its surface. A novel hybrid supercapacitor using AG-MnO2 and LiMn2O4 as negative and positive electrodes has been developed. The effect of operating potential window of negative electrode on the performance of the hybrid supercapacitor has also been investigated in this paper. The results showed that combined high capacitance AG-MnO2 material with a wide operating potential window of the negative electrode, the energy density of hybrid supercapacitor can reach to 92 Wh·kg-1 （based on active material mass of positive and negative electrodes）, almost five times higher than that of carbon supercapacitor. After 1000 cycles, the capacitance of this new hybrid supercapacitor still remained above 80% of original value.