碳纳米管导电网对LiFePO_4电极材料电化学性能影响

Effect of CNTs as conductive network on electrochemical properties of LiFePO_4 cathode meterials

通过使用碳纳米管(CNTs)构建三维空间导电网络,改善LiFe PO4颗粒之间的电子传导能力,研究其对LiFe PO4正极材料电化学性能的影响,并与不含CNTs的LiFe PO4正极材料进行了对比。研究结果表明,含有CNTs导电网络的电池极化程度和界面阻抗明显小于不含CNTs的电池。在0.1 C充放电倍率下,前后者首次放电比容量分别为165.6和164.4 m Ah/g,低倍率容量几乎相差不大;而在10 C充放电条件下,前者首次放电比容量达到121.9 m Ah/g,明显高于后者的109.8 m Ah/g;以1 C充电10 C放电循环1 000次,前者容量几乎无衰减,后者衰减27.8%。

Carbon nanotubes（CNTs） were used to form a three-dimensional conductive network to improve the conductivity of LiFe PO4 particles.The electrochemical properties of LiFe PO4/CNTs cathode materials were investigated and compared with the LiFe PO4 without CNTs. The results indicate that the LiFe PO4/CNTs has a cover polarization voltage and interface impedance lower than the latter＇s. The initial discharge capacities for both were165.6 m Ah/g and 164.4 m Ah/g respectively when charge/discharge at 0.1 C, which demonstrated narrow gap between the both at low-rate. However, when charge/discharge at 10 C, the former initial discharge capacity exhibited 121.9 m Ah/g showing significantly higher than the latter＇s 109.8 m Ah/g. The former maintained the capacity after 1 000 cycles, but the latter faded 27.8% at 1 C charge/10 C discharge.