作　　者： ; ; ; ; ; ;

机构地区： 河南大学

出　　处： 《复合材料学报》 2013年第1期135-140,共6页

摘　　要： 以水溶性酚醛树脂为碳源,Li2CO3为锂源,纳米FePO4前躯体为铁源和磷源,以水为介质,采用湿法研磨混合均匀,然后通过高温固相法制备出纳米磷酸亚铁锂/碳(LiFePO4/C)复合材料。采用XRD、SEM、TEM、TG和拉曼光谱对该复合材料进行了表征,并研究了其电化学性能。结果表明,制备的LiFePO4/C纳米颗粒为类球形,表面均匀地包覆了一层约5nm厚的碳层,作为锂离子电池正极材料表现出良好的倍率性能和循环性能,在0.2C(1C=170mAh·g-1)、0.5C、1C、2C、5C、10C下首次放电容量分别为151、150、146、142、132、119mAh·g-1,20C下的首次放电容量也达105mAh·g-1,且循环50次几乎无衰减。 The nano- LiFePO4/C composites were prepared by means of wet grinding and following high temperature solid-state reaction using water-soluble phenolic resin, LiaCOa, and nano-FePO4 as precursors. The composites were characterized by XRD, SEM, TEM, TG and Raman spectroscopy and their electrochemical performances were studied. The results show that the as-prepared LiFePO4/C nano-composites are spherical-like particles which consist of a carbon shell with a thickness of about 5 nm and the LiFePO4 core, and show excellent high-rate performance and cycling performance as the cathode for lithium ion batteries. The initial discharge capacities at rates of 0.2 C （1 C=170 mAh · g-1）, 0.5 C, 1 C, 2 C, S C and 10 C are 151 mAh · g-1 , 150 mAh ·g-1, 146 mAh · g-1, 142 mAh ·g-1, 132 mAh · g-1 and 119 mAh · g-1, respectively. The material still shows initial discharge capacity of 105 mAh · g-1 even at 20 C and its capacity doesn＇t decay after 50 cycles.

关 键 词： 酚醛树脂 磷酸亚铁锂 锂离子电池 正极材料 电化学性能

领　　域： [理学] [理学]