Effects of thermal insulation layer material on thermal runaway of energy storage lithium battery pack

The safety accidents of lithium-ion battery system characterized by thermal runaway restrict the popularity of distributed energy storage lithium battery pack. An efficient and safe thermal insulation structure design is critical in battery thermal management systems to prevent thermal runaway propagation. An experimental system for thermal spreading inhibition of lithium-ion battery modules was set up, in order to achieve the goal of zero spreading of thermal runaway between lithium-ion batteries in the module by using thermal insulation layer. And the effects of six different materials of thermal insulation layer on the thermal spreading process of lithium-ion battery modules were investigated. The results showed that the use of thermal insulation layers can effectively inhibit the thermal spread in the battery module. The average spreading time of each cell in the module with nanofiber insulation increased by 5.27 and 7.36 times, compared with that of the module without insulation. Compared with the use of nanofiber insulation layer, the thermal spreading between lithium batteries in the module is completely suppressed by the use of composite phase change insulation layer. The goal of zero spreading of thermal runaway within the module has been realized. The thermal spreading interval between the thermal runaway battery and the neighboring batteries in the module is increased to an infinite length, and only the thermal runaway battery shows the phenomenon of spraying valve such as fire and smoke. It is expected to have a guidance for the design of thermal insulation in lithium-ion battery modules.