【摘要】 通过溶胶凝胶法合成了石墨烯包覆的橄榄石型LiFePO4/石墨烯正极复合材料。实验采用在磷酸铁锂前驱体制备过程中加入石墨烯,经高温煅烧后实现了石墨烯与磷酸铁锂的均匀包覆。研究了石墨烯对正极材料的结构和电化学性能的影响。研究结果表明,LiFePO4/石墨烯复合材料的颗粒尺寸比纯LiFePO4明显减小,石墨烯包覆后的LiFePO4材料的电荷转移电阻显著降低,在0.1 C电流密度下的首次充放电比容量达到143.6 mAh/g,循环性能也得到较大提高。更多还原

【Abstract】 Olivine-type LiFePO4 /graphene composite materials were synthesized by sol-gel method. Graphene was added into the preparation process of LiFePO4 precursor, then the mixture was sintered in high temperature to achieve LiFePO4 coated with graphene evenly. The structure and electrochemical properties of graphene-coating LiFePO4 were investigated. The results indicated that LiFePO4 /graphene particle sizes decreased dramatically by sol-gel method. The charge resistance of LiFePO4 was significantly reduced by coating with high conductive graphene, whereas the initial discharge capacity and cycling performance were greatly increased.更多还原