Non-destructive fast charging algorithm of lithium-ion batteries based on the control-oriented electrochemical model. (15th October 2017)

• Record Type: Journal Article
• Authors: Chu, Zhengyu; Feng, Xuning; Lu, Languang; Li, Jianqiu; Han, Xuebing; Ouyang, Minggao
• Is Part Of: Applied energy. Volume 204(2017)
• Page Start: 1240
• Page End: 1250
• Publication Date: 2017-10-15
• Subjects: Lithium-ion battery -- Electrochemical model -- Lithium deposition -- Fast charging -- Over-potential observer; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2017.03.111
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: A novel non-destructive fast charging algorithm of lithium-ion batteries is proposed. A close-loop observer of lithium deposition status is constructed based on the SP2D model. The charging current is modified online using the feedback of the lithium deposition status. The algorithm can shorten the charging time and can be used for charging from different initial SOCs. The post-mortem observation and degradation tests show that no lithium deposition occurs during fast charging. Abstract: Fast charging is critical for the application of lithium-ion batteries in electric vehicles. Conventional fast charging algorithms may shorten the cycle life of lithium-ion batteries and induce safety problems, such as internal short circuit caused by lithium deposition at the negative electrode. In this paper, a novel, non-destructive model-based fast charging algorithm is proposed. The fast charging algorithm is composed of two closed loops. The first loop includes an anode over-potential observer that can observe the status of lithium deposition online, whereas the second loop includes a feedback structure that can modify the current based on the observed status of lithium deposition. The charging algorithm enhances the charging current to maintain the observed anode over-potential near the preset threshold potential. Therefore, the fast charging algorithm can decrease the charging time while protecting the health of the battery. The fast charging algorithm is validated on a commercial large-format nickel cobalt manganese/graphite cell. The results showed that 96.8% of the battery capacity can be charged within 52 min. The post-mortem observation of the surface of the negative electrode and degradation tests revealed that the fast charging algorithm proposed here protected the battery from lithium deposition.