软包装磷酸铁锂电池包装膜与涂碳铝集流体性能研究

发布时间：2019-06-09 13:41

【摘要】：近年来电动汽车产业发展迅速，动力电池的需求急剧增加。磷酸铁锂电池由于在循环寿命、安全性，甚至成本等方面的显著优势成为动力电池的首选。同时锂离子电池不同于水溶液电池的工作原理使其可以采用软包装结构。由于采用铝塑复合膜包装的工艺，这使得磷酸铁锂动力电池比能量和安全性等方面进一步得到提高。作为磷酸铁锂动力电池重要原材料之一，，铝塑复合膜的性能，如电解液耐蚀性、热封装紧密性等对电池有着重要影响。本论文采用示差扫描量热法（Differential Scanning Calorimetry）对铝塑复合膜进行热分析，根据DSC结果得到铝塑复合膜的最佳热封装温度。此外，针对铝塑复合膜在实际应用中出现的肉眼难以观测的针孔和内表层露铝，研究中尝试以铝塑复合膜为阴极，在含铜离子的溶液中电沉积铜以检测铝塑复合膜的微破损，该方法具有操作简单、现象明显的优点。目前磷酸铁锂动力电池的另一个缺点是低温性能较差，研究中利用激光粒度分析仪、比表面分析仪、XRD、ICP等对不同的磷酸铁锂进行对比分析，在此基础上通过测试成品电池的低温性能以了解磷酸铁锂对成品电池低温性能的影响，结果表明正极材料对软包装磷酸铁锂动力电池低温放电性能影响明显。最后测试了行业中新出现的涂碳铝箔正极集流体，结果表明涂碳铝箔集流体不仅可以显著降低电池充放电时候的极化，同时也可以提高软包装电池的保液量，进一步提高动力电池的循环性能，此外，在生产中也更容易提高电池制片合格率和控制电池内阻分布。
[Abstract]:In recent years, the electric vehicle industry has developed rapidly, and the demand for power batteries has increased sharply. Lithium iron phosphate battery has become the first choice for power battery because of its remarkable advantages in cycle life, safety and even cost. At the same time, the working principle of lithium-ion battery is different from that of aqueous solution battery, so that it can adopt soft packaging structure. Due to the process of aluminum-plastic composite film packaging, the specific energy and safety of lithium iron phosphate power battery have been further improved. As one of the important raw materials for lithium iron phosphate power battery, the properties of aluminum-plastic composite film, such as electrolyte corrosion resistance, thermal packaging tightness and so on, have an important impact on the battery. In this paper, the thermal analysis of aluminum-plastic composite film was carried out by differential scanning Calorimeter (Differential Scanning Calorimetry). According to the results of DSC, the optimum thermal packaging temperature of aluminum-plastic composite film was obtained. In addition, in view of the pinhole and inner surface dew aluminum which is difficult to be observed by the naked eye in the practical application of aluminum-plastic composite film, the aluminum-plastic composite film is used as cathode to electrodeposit copper in solution containing copper ion to detect the micro-damage of aluminum-plastic composite film. This method has the advantages of simple operation and obvious phenomenon. At present, another disadvantage of lithium iron phosphate power battery is the poor performance at low temperature. Laser particle size analyzer, specific surface analyzer and XRD,ICP are used to compare and analyze different lithium iron phosphate. On this basis, the low temperature performance of the finished battery was tested to understand the effect of lithium iron phosphate on the low temperature performance of the finished battery. The results showed that the cathode material had obvious effect on the low temperature discharge performance of the soft packaged lithium iron phosphate battery. Finally, the new carbon-coated aluminum foil positive collector fluid in the industry is tested. the results show that the carbon-coated aluminum foil collector can not only significantly reduce the polarization of the battery during charge and discharge, but also increase the liquid retention of the soft packaging battery. The cycle performance of power battery is further improved, in addition, it is easier to improve the qualified rate of battery production and control the distribution of battery internal resistance in production.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM912

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