石墨烯包覆SnO2空心球的制备及其锂离子电池负极性能

以K2SnO3为原料,采用简单的水热反应,通过基于静电引力的自组装机制,制得石墨烯包覆SnO2空心球的复合材料.采用SEM、TEM、XRD、N2吸附等温线研究了复合材料的形貌和结构；采用电化学方法研究了复合材料的锂离子电池负极性能.结果表明,复合材料为石墨烯包覆的直径约200～300nm的SnO2空心球,比表面积为140.1 m2·g-1.当放电电流密度为158m A·g-1时,充电比容量为425 mAh·g-1,库伦效率保持为92%以上,复合材料具有良好的循环性能.

Preparation and Performance of Graphene-encapsulated SnO2 Hollow Spheres as Anode Materials for Lithium ion Batteries

Graphene-encapsulated SnO2 hollow spheres composite （G-mh-SnO2） were synthesized by a simple hydrothermal method with K2SnO3as the precursor. This process was based on electrostatic self-assembly mechanism. Morphology and structure of resultant composite were characterized by SEM, TEM, XRD and nitrogen adsorption isotherms. Performance of the prepared composite as anode materials for lithium ion batteries was investigated by electrochemical method. The results showed composite was a graphene encapsulated SnO2 hollow spheres with a diameter of 200-300nm. The specific surface area was 140.1 m2·g-1. The charge specific capacitance was 425 mAh·g-1 at the current density of 158m A·g-1 after 50 cycles, and coulombic efficiency was up to 92%. The as-prepared exhibited bettercycling performance.