摘要
采用新的溶胶凝胶工艺,即在溶胶中加入活性炭与柠檬酸、聚乙烯醇和聚乙二醇等添加剂,制得具有尖晶石结构的新型准纳米晶Li4Ti5O12。测试表明,加入活性炭和聚乙二醇制备出的材料性能最优异,首次嵌脱锂效率可达99.2%,20mA/g电流条件下的可逆嵌锂容量为122.1mAh/g,嵌脱锂平台非常稳定。将其制成嵌锂电极后与活性炭电极构成新型的Li4Ti5O12/AC非对称电化学电容器。电化学测试表明,在20mA/g电流条件下,其Li4Ti5O12电极比电容量为103.5mAh/g,充放电效率达96%,充放电曲线的对称性、线性保持较好,电容器内阻小,大电流充放电性能突出。
A novel pseudo-nanocrystalline Li4Ti5O12 spinel was prepared with a new sol-gel processing, we added activated carbon and citric acid, polyvinyl alcohol, polyglycol for additives to the sol. The spinel added with activated carbon and polyglycol showed the best lithiation performance. Its reversible capacity was more than 122. 1mAh/g at a 20mA/g current density, the first charge-discharge efficiency was 99. 2% and its charge-discharge potential was flat and steady. Then, the Li4Ti5O12/AC hybrid capacitors using Li4Ti5O12 as the anode and activated carbon as the cathode were assembled. Electrochemical tests showed that at a current density 20mA/g, the specific capacity of Li4Ti5O12 electrode was 103. 5mAh/g and the efficiency of hybrid capacitor was 96%. Symmetry and linearity of the charge-discharge curve for the hybrid capacitor kept well, and its resistance was little, high power performance was good.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2008年第5期817-820,共4页
Journal of Functional Materials
基金
国家重点基础研究发展规划(973计划)资助项目(2002CB211800)
国家高技术研究发展计划(863计划)资助项目(2006AA11A165)
