Internal short circuit evaluation and corresponding failure mode analysis for lithium-ion batteries

Internal short circuit (ISC) is the major failure problem for the safe application of lithium-ion batteries, especially for the batteries with high energy density. However, how to quantify the hazard aroused by the ISC, and what kinds of ISC will lead to thermal runaway are still unclear. This paper investigates the thermal-electrical coupled behaviors of ISC, using batteries with Li(Ni1/3Co1/3Mn1/3)O-2 cathode and composite separator. The electrochemical impedance spectroscopy of customized battery that has no LiPF6 salt is utilized to standardize the resistance of ISC. Furthermore, this paper compares the thermal-electrical coupled behaviors of the above four types of ISC at different states-of-charge. There is an area expansion phenomenon for the aluminum-anode type of ISC. The expansion effect of the failure area directly links to the melting and collapse of separator, and plays an important role in further evolution of thermal runaway. This work provides guidance to the development of the ISC models, detection algorithms, and correlated countermeasures. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.