Abstract: The thermal runaway of lithium battery caused by bumping and external short circuit during transportation and use is very easy to induce the surrounding batteries to heat up, leading to the spread of thermal runaway. In order to control the thermal runaway propagation of lithium batteries, this paper uses nanofiber materials to inhibit heat propagation, and uses corrugated paper, ceramic fiber and glass fiber as spacer materials to carry out the thermal runaway test of lithium batteries, and evaluates the insulation materials in terms of heat insulation and fire resistance. The results show that although the thermal insulation performance of the nanofiber material will prompt the first battery to enter the thermal runaway state faster, the propagation of the thermal runaway of the lithium battery can be effectively suppressed due to its good thermal insulation performance. The heat flux density of the thermal insulation materials during the combustion explosion of the first battery is measured, and it is found that the peak heat flux of ceramic fiber paper is lower, and the thermal insulation performance of nanofiber materials is better than that of corrugated paper. At the same time, the fire resistance of the three materials was tested to determine the reliability of the materials during the battery explosion, and it was found that the corrugated paper was very easy to burn, while the nanofiber material had good thermal stability. The results demonstrate the feasibility of nanomaterials as transportation spacers for lithium batteries.

Key words: lithium battery, thermal runaway propagation, nanofiber material, ignition and explosion, temperature