钠源对P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_2性能的影响

采用不同钠源在醋酸盐燃烧下合成P2结构的Na_(2/3)Ni_(1/3)Mn_(2/3)O_2正极材料。通过XRD、SEM及循环伏安、电化学阻抗谱等测试,分析钠源对材料结构、形貌及电化学性能的影响。以碳酸钠为钠源合成的样品的层状结构较好、颗粒粒径较均一,电化学性能最好。该材料以0.1 C在2.0~4.0 V循环,首次放电比容量为89.8 m Ah/g,库仑效率为123.3%。1.0 C首次放电比容量为74.3 m Ah/g,第50次循环的放电比容量为71.1 m Ah/g,容量保持率为95.7%。

Effect of sodium sources on performance of P2-Na2/3Ni1/3Mn2/3O2

The P2 structure Na2/3 Ni1/3 Mn2/3 O2 cathode material was synthesized with different sodium sources by acetate combustion method.XRD,SEM,cyclic voltammogram and electrochemical impedance spectroscopy were employed to characterize the influence on structure,morphology and electrochemical performance of the materials.The better layered structure,the uniform particle size and the optimal electrochemical performance were achieved for the sample synthesized with Na2 CO3 as Na sources.The initial discharge capacity of 89.8 mAh/g and the coulombic efficiency of 123.3％ at 0.1 C in 2.0-4.0 V.The initial discharge capacity was 74.3 mAh/g at 1.0 C,the discharge capacity was 71.1 mAh/g and the capacity retention was 95.7％ after 50 cycles.