摘要
采用非水溶液溶胶-凝胶法,并结合高温碳热还原法制备锂离子电池用高可逆容量的Sn-C复合负极材料,通过调节Sn源与炭源的比例及碳热还原过程中的升温制度来控制金属Sn的粒度和Sn-C复合材料的结构形态。借助XRD、EDS、SEM、循环伏安及恒流充放电测试对材料的物化性能进行表征。结果表明,当Sn源与C源质量比为80:20、还原温度为800℃时,纳米级金属Sn均匀紧密地分布在无定形热解炭基体中,形成良好的纳/微复合结构,此时复合材料性能相对最优;该复合材料在电流密度为100 mA/g,首次可逆比容量为637.9 mAh/g,循环30次后充电容量保持在372.5 mAh/g以上,第二次循环库伦效率达到97%以上。
Sn/C composites were synthesized via the anhydrous sol-gel method united with high temperature carbon thermal reduction method as a lithium battery of high reversible capacity anode.The morphology and granulometric distribution of the Sn/C composites were controlled by adjusting Sn/C ratio and the heating schedule during carbon thermal reduction.Physical and electrochemical properties were investigated by XRD,EDS,SEM,potential-sweep cyclic voltammetry,and galvanostatic charge and discharge tests.The results show that nano-scale Sn particles disperse evenly in a carbon matrix and form a kind of nano-micron structure when the mass ratio of the stannic oxide and phenolic resin is 80：20 at the reduction temperature of 800 ℃.The Sn/C composite exhibits an initial reversible capacity of 637.9 mAh/g at first cycle,decays to a stable value of 372.5 mAh/g after 30 cycles,and coulomb efficiencies of 97% are obtained after the first cycle at constant current density of 100 mA/g.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2012年第2期182-188,共7页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学基金资助项目(50974136
51074185)
中央高校基本科研业务费专项基金资助
关键词
锂离子电池
纳-微结构
溶胶-凝胶法
碳热还原法
lithium ion battery
nano-micron structure
sol-gel method
carbon thermal reduction method
