Abstract: The inhibition effect of various thermal insulation materials, such as glass fibre, super cotton and alumina silica gel, on the thermal runaway propagation of the battery is investigated through the thermal runaway propagation experiment of 280 Ah lithium iron phosphate battery. The results show that all the materials can retard the thermal runaway propagation, among which the super cotton (with the thickness of 2.3 mm) performs the best, which can achieve the propagation blocking, and the highest thermal insulation efficiency reaches 74.5%. Heat transfer analysis showed that the low thermal conductivity and porous structure of the super cotton material had a significant shielding effect on heat. In contrast, glass fibre and aluminium oxide silica gel have a relatively weak inhibiting ability. In addition, although the thermal insulation structure can block the heat propagation, it is also easy to lead to the intensification of heat accumulation inside the first thermal runaway battery, and the thermal runaway reaction is more intense.

Key words: lithium-ion battery, thermal runaway propagation, thermal insulation, heat distribution, heat transfer analysis