【摘要】 为了提高LiFePO4材料的电化学性能,以碳溶胶和葡萄糖两种物质为碳源、采用高温固相法制备了LiFePO4/C复合正极材料。通过XRD、TEM、恒电流充放电等方法研究了材料的结构与电化学性能。XRD结果表明,两种碳源的添加对LiFePO4的晶体结构没有影响。从TEM图上可观测到颗粒外部明显的碳包覆层。电化学性能测试表明,在同样倍率下,以两种碳源制备的LiFePO4/C材料放电比容量高于以单一碳源制备的LiFePO4/C,且表现出优良倍率性能和循环稳定性:在0.1C下的放电比容量达162mAh/g,1C下放电比容量为157mAh/g,循环20次后容量没有任何衰减。更多还原

【Abstract】 In order to improve the electrochemical performances of LiFePO₄,LiFePO₄/C composite was synthesized via solid-state reaction with two kinds of carbon sources: carbon sol-gel and glucose.The structure and electrochemical properties of the LiFePO₄/C composite were characterized by XRD,TEM and galvanostatic charge-discharge.The electrochemical measurement and XRD results indicate that carbon coating doesn′t work on the phase of LiFePO₄.A distinct carbon layer can be observed surrounding the LiFePO₄ particle by TEM.LiFePO₄/C synthesized with two kinds of carbon sources shows higher discharge specific capacity than LiFePO₄/C with single carbon source at the same rate,it also shows good rate performance and cycle stability.A discharge specific capacity of 162mAh/g is obtained at 0.1C,and 157mAh/g is obtained at 1C,no loss of capacity is found after 20 cycles.更多还原