Detection of the Chain Reaction Pathway and Early Warning Method of Thermal Runaway by Battery Management System for Lithium Nickel Manganese Cobalt Oxide Batteries

Thermal runaway in power batteries represents a critical limitation for the sustainable development of electric vehicles, particularly as their adoption increases. The chain reaction of thermal runaway occurs within micrometer-scale regions over brief time periods, involving complex reaction mechanisms that prevent real-time monitoring of internal battery reactions. While existing warning methods for chain reactions monitor battery temperatures, internal short circuits, reaction gas evolution, and mechanical deformation, no early warning method based on the reaction mechanism for the chain reaction process currently exists. This study examines the battery thermal runaway chain reaction and associated electrode capacity changes. By analyzing their correlation, this research identifies internal battery reaction characteristics through capacity variations and investigates thermal runaway chain reaction processes. Based on experimental measurements of the correlation between battery side reaction rates I red and I ox and thermal runaway, this study proposes an online early warning system using | I red | and | I ox | to prevent thermal runaway occurrence. This non-intrusive battery management system warning method offers a cost-effective early warning solution with practical applications for enhancing electric vehicle safety.