Quantitative safety assessment of lithium-ion batteries: Integrating abuse risks and intrinsic safety

Abstract

Lithium-ion batteries (LIBs) safety have become a critical concern with increasing use across various applications. Existing methods for assessing LIB safety predominantly focus on isolated abuse conditions, often neglecting the combined impact of both intrinsic risks and safety factors, especially in aged batteries. In this study, a multi-factor quantitative assessment method for the safety of LIBs is proposed based on the fuzzy analytic hierarchy process (FAHP). Characteristic parameters with the highest correlation are extracted via analysis of intrinsic and abuse safety. In the proposed method, both simplified engineering model (SEM) and generalized system model (GSM) are established for the quantitative safety assessment and grading of fresh and aged batteries. A case study of LIBs using lithium cobalt oxide (LCO) cathode materials demonstrates that gas generation significantly increases safety risks, while aging reduces risks under thermal and electrical abuse but does not affect mechanical abuse. The findings highlight that swollen batteries have elevated risks due to gas generation, emphasizing the importance of monitoring aging effects in battery safety. The SEM has the advantages of simplicity for engineering applications, while the GSM is more comprehensive and accurate. This study provides a reliable and effective approach for the management and recycling of LIBs.