不同导电剂体系对LiFePO_4锂离子电池性能的影响

Effect of different conductive additives on performance of LiFePO_4 lithium-ion battery

研究了不同导电剂体系(Super P、VGCF)的LiFePO_4锂离子电池的性能。利用SEM及充放电方法对极片表面形貌和电池的电化学性能进行了表征和测试。SEM测试表明,VGCF分散性能良好,在正极片中形成良好的三维导电网络结构。极片面电阻测试表明,添加VGCF后正极片面电阻明显降低。电性能测试表明,添加VGCF的电池性能明显优于SP作导电剂的电池,大倍率放电性能改善明显,常温1 C/2 C循环700次容量保持率分别为99.40%和94.86%。

The performance of LiFePO4 lithium-ion battery with different conductive additives such as Super P and VGCF were investigated. The surface morphology of cathode was tested by SEM. The electrochemical performance of the batteries was tested by charge--discharge methods. SEM indicates that VGCF could disperse well and form favorable three-dimensional conductive network in cathode plate. The test indicates that the area resistance of plate with addition of VGCF reduces. Electrochemical tests show that the battery with addition of VGCF has better performance than battery using common conductive agent. Rate charge/discharge performance is improved obviously. The capacity retention respectively are 99.4% and 94.86% after 700 cycles of 1 C/2 C at room temperature.