Experimental Study on Thermal Runaway Behavior of Lithium-Ion Battery and Analysis of Combustible Limit of Gas Production

Abstract

Lithium-ion batteries (LIBs) are widely used in electric vehicles (EV) and energy storage stations (ESS). However, combustion and explosion accidents during the thermal runaway (TR) process limit its further applications. Therefore, it is necessary to investigate the uncontrolled TR exothermic reaction for safe battery system design. In this study, different LIBs are tested by lateral heating in a closed experimental chamber filled with nitrogen. Moreover, the relevant thermal characteristic parameters, gas composition, and deflagration limit during the battery TR process are calculated and compared. Results indicate that the TR behavior of NCM batteries is more severe than that of LFP batteries, and the TR reactions becomes more severe with the increase of energy density. Under the inert atmosphere of nitrogen, the primarily generated gases are H2, CO, CO2, and hydrocarbons. The TR gas deflagration limits and characteristic parameter calculations of different cathode materials are refined and summarized, guiding safe battery design and battery selection for power systems.

Chemical Thermal Runaway Modeling of Lithium‐Ion Batteries for Prediction of Heat and Gas Generation

“…Literature data with comparable experimental setups report around 1.5-2.5 L Ah À1 for overheating tests on NMC cells. [35][36][37][38] The reason for the relatively high amount of released gas in this work is the high initial electrolyte mass fraction compared to commercial cells [39] as electrolyte solvent contributes to several gas-producing decomposition reactions (see Section 2).…”

Experiments investigating the thermal runaway behavior of cyclically aged lithium batteries at various SOCs

“…Subsequently, the chemical reactions of the internal materials, such as SEI decomposition, cathode decomposition, anode-electrolyte reactions, etc., release heat [26], causing the battery temperature to slowly rise again. Moreover, with the temperature further increasing, the chemical reaction rate accelerates, leading to a faster temperature rise in the battery [27].…”

“…The experimental ndings reveal that TR (thermal runaway) generates a signi cant amount of gas. Furthermore, the electrolyte in the battery can vaporize at high temperatures, resulting in the formation of large molecular organic compounds [27]. Despite the four batteries being identical, there are signi cant differences in the gas generation rates.…”

“…Despite the four batteries being identical, there are signi cant differences in the gas generation rates. The gas generation equation for the battery is formulated as follows [27].…”

“…In order to analyze the gas generation rates of the four batteries, the gas generation rates were normalized, and the mass loss and normalized gas generation rates were plotted as shown in Fig. 7, following the methodology described in reference [27].…”