讲座人：美国普渡大学（Purdue University）谢剑教授
讲座题目：锂离子电池的失效研究(Failure Investigation of Li-Ion Batteries)
讲座时间：2018年11月23日 上午9:00-12:00
讲座地点：学校学术交流中心第六会议室
报告人简介：谢剑教授现为美国普渡大学印第安纳波利斯分校工学院机械与能源工程系教授。主要研究方向为聚合物燃料电池，锂金属电池研究，纳米及复合材料。已发表55篇高水平期刊论文，2个专著章节，拥有11项专利，近10年获得研究经费超过586万美元。是包括Nature和Science等12个杂志的特约审稿人，美国国家科学基金会、高级研究项目机构-能源燃料电池技术办公室、美国能源部技术转让办公室和加拿大国家科学基金会的评审员。
讲座摘要：Lithium ion batteries (LIBs) have the highest specific energy and energy density among the different battery technologies. This high specific energy and energy density are desired for many applications, but are the potential causes of safety incidents, which could cause detrimental damage to valuable property and could even cost human lives. Therefore, the safety of LIBs is of a great importance to their application in portable electronics, electric and hybrid electric vehicles, and military devices and systems. To maintain safe operation of a LIB cell, it is necessary to monitor the state of health of that cell. In order to do so, LIB failure needs to be comprehensively investigated including failure modes, failure causes, signs of early failure, detection methods to catch early failure signs, etc. Then, a system should be developed to monitor the LIB state of health. We have formed a team of government, academia, and industry professionals to investigate the failure of LIBs. A comprehensive and systematic approach has been taken to study the failure mechanism. A small degree (no more than 20%) overcharge/overdischarge will cause the failure of LIBs. A synchrotron high-energy x-ray coupled with electrochemical testing was used to study the in situ structural changes of the electrode materials during the charge/discharge cycle. The in situ structural changes of the cathode were also studied. When LIB cell was overdischarged, the corrosion of the Cu current collector was found to be the major cause of LIB failure because of the Cu dendrite formation while under overcharged, the formation of Fe dendrites was the major cause of the failure. The failure mechanism of LiFePO4 cell under overcharge and over discharge conditions have been elucidated from our experimental investigation. The signatures of failure have been identified experimentally. The model/algorithms have been developed for early warning detection. A prototype of the detection system which can detect the early signs of failure has been developed.
