(1. 中南大学 冶金与环境学院，长沙 410083；
2. 中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 针对本征低的电子导电率和锂离子迁移速率导致LiFePO4较差的电化学性能，以石墨烯作为模板，采用一步溶剂热法制备梭形结构的LiFePO4/石墨烯(LFP/G)复合正极材料；采用XRD和SEM等表征复合正极材料的物相结构和微观形貌，微米级梭型LiFePO4颗粒是由平均厚度约为55 nm的纳米薄片堆叠而成。电化学性能研究结果表明：在0.1C倍率下，LFP/G复合正极材料的初始可逆比容量可达153.2 mA？h/g，高于相同条件下LiFePO4的；在10C倍率下充放电时，LFP/G表现出高达85.9 mA？h/g的可逆比容量，远高于LiFePO4的可逆比容量(56.3mA？h/g)，展现出明显增强的电化学倍率性能。
关键字: 磷酸铁锂纳米片；石墨烯复合材料；梭型结构；正极材料；锂离子电池
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Aiming at the intrinsic shortcomings of LiFePO4, a spindle-like LiFePO4/graphene (LFP/G) composite cathode material was conveniently prepared by a one-step solvothermal method using graphene as a template. The as-obtained material was characterized by XRD, SEM and other methods. The results show that the micron-sized spindle-like LiFePO4 particles are stacked by nano-sheets with average thickness of about 55 nm. Electrochemical performance study results show that the LFP/G composite cathode material exhibits an initial reversible specific capacity of 153.2 mA？h/g at 0.1C rate, which is higher than that of LiFePO4 under the same conditions; when charged and discharged at 10C rate, LFP/G exhibits a reversible specific capacity of up to 85.9 mA？h/g, which is much higher than that of LiFePO4 (56.3 mA？h/g), exhibiting significantly enhanced electrochemical rate performance.
Key words: LiFePO4nanoflakes; graphene composite; spindle-shaped structure; cathode material; lithium-ion batteries
