钒掺杂对Li4Ti5O12性能的影响

采用固相反应法合成了锂离子电池负极材料Li4-xVxTi5O12(x=0,0.1,0.2),研究了钒掺杂对其晶格结构、相组成和颗粒形貌以及电化学性能的影响。结果表明:钒的掺杂增大了Li4-xVxTi5O12的晶胞参数,降低了晶格的规整度,增大了合成Li4-xVxTi5O12的颗粒度;同时随着钒掺杂量的增加,Li4-xVxTi5O12在高倍率下的循环稳定性增加,电极极化程度变小。Li4Ti5O12在3.0C下的比容量衰减迅速,但Li4-xVxTi5O12(x=0.1,0.2)在3.0C下仍保持很好的循环稳定性。钒的掺杂降低了Li4Ti5O12的比容量,这与钒在晶格中的存在形式以及掺杂试样较大的颗粒度有直接关系。

Effect of vanadium doping on the performance of Li4Ti5O12

Li_(4-x)V_xTi_5O_(12)(x=0,0.1,0.2) anode material of Li-ion battery was synthesized by solid state reaction and the(effects) of vanadium doping on its lattice structure,phase composition,particle morphology and electrochemical performance were investigated.The results indicated that the vanadium doping increased the lattice parameter,decreased the crystallinity and enlarged the particle size of synthesized Li_(4-x)V_xTi_5O_(12).With the increase of doping amount of vanadium,the cycling stability of Li_(4-x)V_xTi_5O_(12) at high current rate was improved and the electrode polarization was minimized.The specific capacity of Li_4Ti_5O_(12) decreased rapidly at 3.0 C,while Li_(4-x)V_xTi_5O_(12)(x=0.1,0.2) showed an excellent cycling stability at(3.0 C).The doping of vanadium decreased the specific capacity of Li_4Ti_5O_(12),which was related to the existing form of vanadium in the lattice and the large particle size of the doped sample.