摘要
通过简单的石墨相氮化碳(g-C_3N_4)纳米片自组装沉积法,制备了g-C_3N_4包裹的SnO_2-TiO_2纳米复合材料.扫描电子显微镜观察显示,g-C_3N_4均匀地包裹在SnO_2-TiO_2纳米颗粒上.SnO_2-TiO_2-C_3N_4纳米复合材料被用作锂离子电池的负极材料,在0.2C的倍率下循环20次后,比容量达到380.2mA·h·g^(-1),明显高于未经g-C_3N_4包裹的纯的SnO_2(51.6mA·h·g^(-1))和SnO_2-TiO_2纳米复合材料.在0.1~0.5C的倍率充放电测试中,SnO_2-TiO_2-C_3N_4纳米复合材料的比容量仅从490mA·h·g^(-1)衰减到330mA·h·g^(-1),高倍率下抗衰减性能优于同类材料.材料优异的电化学性能归功于g-C_3N_4的包裹处理,这不仅增强了固体电解质界面(SEI)的稳定性,也抑制了锂离子嵌入-脱出时SnO_2和TiO_2纳米颗粒的体积变化.
Graphitic carbon nitride （g-C3N4） coated SnO2-TiO2 nanocomposite was prepared by simple self-assembly deposition of g-CaN4 nanosheets on synthesized SnO2-TiO2 nanocomposite. Scanning electron microscopy reveals that g-C3N4 was uniformly coated on SnO2-Ti02 nanoparticles. The SnOz-TiO2-C3N4 nanocomposite was used as high capacity anode material for lithium ion battery and displayed remarkable higher capacity（380.2 mA ~ h ~ g-l） compared to both pure Sn02（51.6 mA·h·g^-1） and SnO2-Ti02 nanocomposite（114.1 mA·h·g^-1） at 0.2C rate after 20 cycles. Rate test of SnO2-TiO2-CaN4 nanocomposite implied a slight fading of specific discharge capacities from 490 mA·h·g^-1 to 330 mA·h·g^-1 at current rate range of 0.1-0.5C. The significantly improved electrochemical properties of SnO2-TiO2-CaN4 nanocomposites can be attributed to g-C3N4 coating treatment, which not only enhanced the stability of the solid-electrolyte-interface（SEI） film but also act as a buffer layer for the large volume change of SnO2-TiO2 nanoparticles during lithium intercalation.
出处
《有色金属材料与工程》
CAS
2016年第2期1-7,共7页
Nonferrous Metal Materials and Engineering
基金
国家自然科学基金海外港澳学者合作研究基金项目(51528202)
