不同合成方法对LiFePO_4/C正极材料性能的影响

Effects of different synthesis methods on the performance of LiFePO_4/C as cathode material

以磷酸亚铁为原料,分别采用磷酸亚铁与磷酸锂的直接合成法(直接法)和磷酸亚铁与原位合成磷酸锂的合成法(磷酸锂原位合成法)合成了橄榄石型LiFePO4/C复合正极材料。用X射线衍射(XRD)、扫描电镜(SEM)、以及充放电测试等方法对材料进行了结构表征和电化学性能测试。实验结果表明两种不同方法得到的样品具有橄榄石晶体结构。两种方法制得的材料都具有较高的放电比容量及良好的循环稳定性能。磷酸锂原位合成法得到的样品形貌较规则,粒径较细且分布较均匀,其放电比容量略高于直接法合成的样品。

The olivine LiFePO4/C composite cathode materials were synthesized by two different methods which were direct synthesis method and Li3PO4 in-situ synthesis method.The crystal structure and electrochemical performance of samples were characterized by XRD,SEM and gal-vanostatic cell cycling.The test results show that the materials have the olivine crystal structure.The materials synthesized by two different methods show a good electrochemical performance.The samples made by Li3PO4 in-situ synthesized method exhibited higher capacity due to their smaller grain size and homogeneous particale size ditribution.