陶瓷隔膜在32650圆柱动力锂电池中性能研究

Study on the Performance of Ceramic Composite Separators for 32650 Type Cylindrical Lithium-ion Power Battery

运用微凹版涂布方式制备陶瓷复合PE/Al2O3隔膜,并且通过SEM和电化学测试等手段研究隔膜物理与电化学性能。结果表明PE/Al2O3隔膜具有良好的耐高温热稳定性能。采用磷酸铁锂为正极材料,陶瓷复合PE/Al2O3为隔膜,人造石墨为负极材料制成了32650/5000 m Ah的锂离子电池,3 C循环测试300周后容量保持率为94.72%,电池45℃放置7天压降为37 m V。PE/Al2O3隔膜能有效改善电池的自放电和循环等性能。

Composite PE/Al2O3 membrane was prepared by micro gravure coating. The performances of the prepared PE/Al2O3 membrane for lithium ion battery were studied by scanning electron spectroscopy（SEM） and electrochemical measurements. It is found that the PE/Al2O3 membrane has better thermal stability. 32650 type batteries were prepared with lithium iron phosphate as positive electrode, artificial graphite as negative electrode and PE/Al2O3 membrane as separator. The battery has stable discharge capacity retention of 94.72 % after 300 cycles at 3 C rate, and the voltage drop is 37 m V after stored 7 days at 45 ℃. Therefore, the performances of self-discharge and cycle life of battery can be improved by the composite PE/Al2O3 membrane.