焙烧条件对纳/微结构LiFePO4/C性能的影响

Effect of Calcination Conditions on the Performance of Nano/Micro LiFePO4/C

摘要:

LiFePO4具有高容量，热稳定性好及循环性能好等优点，是动力电池的首选材料。本文采用湿法球磨-喷雾干燥-碳热还原反应制备纳/微结构LiFePO4/C复合材料，采用X射线衍射XRD、扫描电镜SEM测定材料的形态结构，通过恒流充放电技术测试焙烧条件对纳/微结构LiFePO4/C电化学性能的影响。结果表明：最佳的焙烧温度为650℃、焙烧时间为8.5 h，此条件下所得的材料常温下10 C放电比容量为123 mAh?g-1，100次循环后容量的保持率接近100%，本文的研究结果可促进LiFePO4作为动力电池的应用。

Abstract:

Olivine structure of lithium iron phosphate (LiFePO4) has been recognized to be the most promising cathode material for electric vehicle due to its high theoretical capacity, outstanding thermal stability, and excellent cycling stability. Nano/micro porous structure LiFePO4/C composites were synthesized by wet milling-spray drying-carbothermal reduction method. X-ray diffraction (XRD), scanning electron microscopy (SEM), were used to determination the morphological structure of materials, constant current charge-discharge test is used to determination the effects of calcination conditions on the electrochemical performances of LiFePO4/C. The results show that: sintered at 650 ℃ for 8.5 h, the sample delivered a discharge capability of 123 mAh?g-1 with no capacity loss after 100 cycles at 10 C under room temperature, showing better discharge capability and cycle performance, these advantages were useful for the application of power batteries.