During thermal runaway (TR), lithium-ion batteries (LIBs) produce a large amount of gas, which can cause unimaginable disasters in electric vehicles and electrochemical energy storage systems when the batteries fail and subsequently combust or explode. Therefore, to systematically analyze the post-thermal runaway characteristics of commonly used LIBs with LiFePO4 (LFP) and LiNixCoyMnzO2 (NCM) cathode materials and to maximize the in situ gas generation during battery thermal runaway, we designed experiments using an adiabatic explosion chamber (AEC) under an inert atmosphere to test LIBs. Additionally, we conducted in situ analysis of the gas components produced during thermal runaway. Our research findings indicate that after thermal runaway, NCM batteries produce more gas than LFP batteries. Based on battery gas production, the degree of harm caused by TR can be ranked as follows: NCM9 0.5 0.5 > NCM811 > NCM622 > NCM523 > LFP. The primary gas components during thermal runaway for both NCM and LFP batteries include H2,CO,CO2,C2H4, and CH4. The gas produced by LFP batteries contains a high proportion of H2. The high concentration of H2 results in a lower flammability limit (LFL) for the gas generated by LFP batteries during TR compared to the mixed gas produced by NCM batteries. Therefore, in terms of battery TR gas composition, the order of hazard level is LFP > NCM811 > NCM622 > NCM523 > NCM9 0.5 0.5 0.5. Although experimental results show that LFP batteries have superior thermal stability and lower gas production during large-scale battery thermal runaway events, considering gas generation composition and thermal runaway products, the thermal runaway risk of LFP batteries may be higher than that of NCM batteries. Although LFP batteries are considered very safe, our research results have once again drawn researchers’ attention to LFP batteries. These gases can also serve as detection signals for battery thermal runaway warnings, providing a cautionary note for the future development of electrochemical energy storage and the renewable energy sector.

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.

Lithium batteries are being utilized more widely, increasing the focus on their thermal safety, which is primarily brought on by their thermal runaway. This paper’s focus is the energy storage power station’s 50 Ah lithium iron phosphate battery. An in situ eruption study was conducted in an inert environment, while a thermal runaway experiment was conducted utilizing sealed pressure containers and an external heating triggering mechanism. Both the amount of gas release and the battery’s maximum temperature were discovered. Using gas chromatography, the gas emission from the battery was examined. Its principal constituents included CO, H2, CO2, CH4, C2H4, and so on. Moreover, the experiment discovered a second eruption of lithium iron phosphate, and the stage of its eruption was separated by the pressure signal of the sealed experimental chamber, giving a theoretical foundation and technological backing for the thermal catastrophe safety of lithium batteries.

In this study, based on the liquid cooling method, A confluence channel structure is proposed, and the heat generation model in the discharge process of three-dimensional battery module is established. The effects of channel structure, inlet mass flow rate and coolant flow direction on the heat generation of battery module were studied by control variable method. Simulation results show that the confluence channel structure ( e ) shows good cooling effect on the battery temperature when controlling the 5 C discharge of the battery module. In addition, compared with the straight channel under the same working condition. In the discharge process of battery module, Average temperature amplitude in battery module decreased by 17.3 %, the inlet and outlet pressure is reduced by 16.47 %, and the maximum temperature amplitude is reduced by 20.3 %. Effectively improve temperature uniformity and reduce pressure drop. The problem of uneven temperature distribution caused by uneven velocity distribution of coolant in traditional straight channel is improved. At the same time, the design of the confluence structure accelerates the heat transfer of the channel plate and provides a new idea for the design of the cooling channel.