SnO_2@C锂离子电池负极材料的制备及其性能

Preparation and Application of SnO_2@C as Anode Material in Lithium Ion Batteries

通过回流法制备了SnO_2纳米小球,再以β-环糊精(β-CD)作为碳源通过水热法制备得到球状纳米SnO_2@/C复合材料.扫描电子显微镜和粉末X射线衍射仪测试结果表明,合成的复合材料为直径约为30~40 nm的纳米小球,在SnO_2的表面可以看到一层均匀的碳层的包覆.通过碳的包覆,材料的结构稳定性和导电性增强.在100 mA/g的电流密度下,200次循环后,放电比容量稳定在749 mAh/g,而在大电流充放电后(100~800 mA/g),再次回到100 mA/g的电流密度时,放电比容量仍能保持在620 mAh/g.

SnO2 nanosphere are prepared by a refluxing method, and SnO2@ C nanosphere have been prepared by hydrothremal with β-eyclodextrin （β-CD）. The results through scanning electron microscopy and X-ray powder diffraction show that the products are SnO2 nanosphere with a diameter of about 30-40 nm which is covered a uni- form carbon layer. After carbon-coated, the structural stability and electrical conductivity of the material are increased. The discharge capacity -current charge and discharge of 100 mA/g. remains 749 mAh/g at current density of 100 mA/g after 200 cycles, and after high （ 100 to 800 mA/g） , the discharge capacity remains 620 mAh/g at current density