锂离子电池正极材料LiV3-xAlxO8的水热合成与性能

采用水热法制备了Al掺杂的锂二次电池正极材料LiV3-xAlxO8,并用X射线衍射和扫描电镜对材料的晶体结构和形貌进行了表征.以50 mA·g-1进行恒流充放电测试,结果表明Al掺杂能够明显改善材料的电化学性能.在掺杂改性的LiV3-xAlxO8材料中,LiV2.93Al0.07O8的初始容量最高,达到325 mAh·g-1.当掺杂量为x=0.04时,材料的循环性能最佳.LiV2.96Al0.04O8经20次循环后仍保持179 mAh·g-1的比容量,且充放电效率始终维持在98%左右.

Hydrothermal Synthesis of LiV3-xAlxO8 and Its Performance as Positive Electrode Material for Lithium-Ion Batteries

Al doped lithiated vanadium oxides LiV_3-xAl_xO₈ as promising positive electrode material for secondary lithium batteries are prepared with a hydrothermal process. The crystalline phase is characterised by powder X-ray diffraction and the morphology is observed by scanning electron microscope. The electrochemical properties of synthesized samples are investigated by galvanostatic charge and discharge at a current density of 50 mA·g^-1. The electrochemical properties were greatly improved via Al doping. Among the doping modified material LiV_3-xAl_xO₈, the maximal initial specific discharge capacity belongs to LiV_2.93Al_0.07O₈ which can attain 325 mAh·g^-1. The most excellent performance can be achieved when x=0.04. The LiV_2.96Al_0.04O₈ material preserves a high charge -discharge efficiency of around 98% and keep a special capacity of 179 mAh·g^-1 after 20 cycles.