Liu Lei

Bio: Liu Lei is an academic researcher from Harbin Institute of Technology. The author has contributed to research in topics: Battery (electricity) & Lithium-ion battery. The author has an hindex of 3, co-authored 14 publications receiving 32 citations.

Internal short circuit mechanisms, experimental approaches and detection methods of lithium-ion batteries for electric vehicles: A review

Abstract: Energy security, environmental concerns, and the upgrading of automobile industry are the driving trifecta of the rapid development of electric vehicles (EVs) Lithium-ion batteries (LIBs) have become the primary power source for EVs, given their high energy/power density and long service lifetime However, safety is still a big challenge facing the population of LIBs Internal short circuit (ISC) is one of the root causes for the failure of LIBs, whereas the mechanism of ISC formation and evolution is still unclear This paper provides a comprehensive review of formation mechanisms, evolution framework, experimental approaches, detection methods and mitigation strategies of ISC in LIBs Learning from the typical safety accidents of LIBs, ISC primarily which caused by typical factors is intensively investigated Later, the behavior and evolution framework of ISC are profoundly elaborated The ISC experimental approaches are systematically classified into conventional experimental approaches and novel experimental approaches, and their advantages and drawbacks are summarized in detail, respectively Further, ISC detection methods including offline and online detection methods are comprehensively analyzed Finally, an insight into the research perspective of ISC mitigation is provided

Toward Sustainable Reuse of Retired Lithium-ion Batteries from Electric Vehicles

Abstract: As attractive energy storage technologies, Lithium-ion batteries (LIBs) have been widely integrated in renewable resources and electric vehicles (EVs) due to their advantages such as high energy/power densities, high reliability and long service time. Although EVs basically do not produce pollution, the end-of-life (EOL) issues of LIBs cannot be ignored due to their potential economic benefits and environmental risks. Current methods for the retired batteries mainly include disposal, recycling and reuse. EV LIBs can be reused in a variety of applications with less demanding. Compared with recycling and disposal, reuse process can obtain better economic and environmental benefits. Many second life EV LIBs projects have been undertaken and demonstrated the great potential of reuse. However, the reuse should consider economic, environmental, technical, and various market perspectives. Technical challenges that must be faced include safety issues, assessment methods, screening and restructuring technologies, and comprehensive management during the reuse process. Economic feasibility issues, comprehensive supply chains, and the lack of relevant regulations also hinder large-scale development of reuse. It is foreseeable that improvements including standardization, big data and cloud-based technologies are desperately needed to maximize the industrialization of reuse and recycling.

Experimental study of the impedance behavior of 18650 lithium-ion battery cells under deforming mechanical abuse

Abstract: Due to rising safety requirements for lithium-ion batteries, the detection of mechanical failure of such batteries is becoming increasingly important. As publications investigating electrochemical impedance spectroscopy (EIS) of lithium-ion battery cells under deforming mechanical abuse as a potential damage detection method are sparse, this work presents tests with stepwise loading of 18,650 lithium-ion battery cells with various impactors (nails, cylindric, hemispheric) and simultaneous EIS measurements to search for indicators which could be used to anticipate hazardous events. The occurrence of different damage mechanisms of the jelly roll is evaluated via computed tomography (µ-CT) and correlated to the measured changes in EIS. For internal short circuits (ISCs) without instantaneous thermal runaway, the results show a decrease of ohmic resistance in the EIS for high measurement frequencies, which is possibly linked to temperature increase, while low frequencies indicate deviations from stationarity or linearity requirements. In the case of large area compression, the EIS measurements display an increase of ohmic resistance, which may be connected to various mechanisms, such as the decrease of porosity of the separator and the active materials or delamination.