摘要
采用溶胶-凝胶法,以柠檬酸和月桂酸作螯合剂和碳源,原位碳化,制备了Li4Ti5O12/C材料。采用XRD、SEM、TEM、TG-DSC以及恒流充放电测试等手段对材料的形貌、结构和电化学性能进行表征。通过研究碳源的含量和煅烧制度对物相结构、颗粒形貌及电化学性能的影响,优化制备工艺。柠檬酸和月桂酸与钛的摩尔比分别为1∶6和1∶20的前驱体在800℃烧结15h后产物的碳含量约为2.3%(质量分数),碳层的厚度约为5～10nm,电化学性能最佳。1C倍率下,放电容量为151.1mAh/g,50次循环后容量无明显衰减。
In situ carbon-coated Li4Ti5O12 composites were prepared by sol-gel route using citric acid and lauric acid as chelate agent and also carbon sources.The crystal structure,microstructure and electrochemical properties of samples were characterized by XRD,SEM,TEM,TG-DSC and galvanostatically charge-discharge experiments.The effects of the content of carbon sources on the phase structure,the microstructure and electrochemical properties were studied to optimize process.The sample prepared with citric acid to titanium molar ratio CTR=1∶6 and lauric acid to titanium molar ratio LTR=1∶20 was coated with a carbon layer of 5-10nm,exhibiting the best electrochemical performance.The carbon content of the sample was about 2.3wt%.Its discharge capacity at 1C rates can reach 151.1mAh/g,respectively.After 50 cycles,fairly stable cycling performance was achieved without obvious capacity fade.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2010年第12期2182-2185,2189,共5页
Journal of Functional Materials
基金
国家自然科学基金资助项目(20803035)
江苏省自然科学基金资助项目(BK200718)
上海市闵行区科技资助项目(2009MH188)
