A Study on dFMEA-based Fire Risk Assessment of Lithium-ion Secondary Battery Testing Cells

In this study, Design Failure Mode and Effects Analysis (dFMEA) was performed to evaluate the fire risk of lithium-ion secondary battery testing cells used during the research and development stage. dFMEA was used for the failure risk analysis, risk assessment, and risk priority analysis of the anode, cathode, separator, electrolyte, and cell design of the testing cell. In addition, the evaluation criteria, including severity, occurrence, and detection, was reorganized into three categories and optimized for the testing cell application. Based on the failure risk analysis, a total of 11 causes of failure were identified. In particular, explosion and thermal runaway were predicted when a nickel-cobalt-manganese (NCM)-based anode material with a high nickel content was used, the separator had a high thermal contraction rate and low tensile strength characteristics, and there were errors in the electrolyte composition optimization. This cause of failure was classified as a moderate risk with a high fire risk by the risk priority analysis. Therefore, at the research and development stage, it is critical to evaluate the mutual reactivity and preliminary physical properties of battery materials and to construct safety equipment to reduce fire damage.