Experimental study on low thermal conductive and flame retardant phase change composite material for mitigating battery thermal runaway propagation

摘要

Lithium-ion batteries (LIBs) have dominated the market in portable electronics, electric vehicles, and aerospace applications. However, safety issues greatly limit the further applications of LIBs. In this work, a low thermal conductive phase change composite material (CPCM) with flame retardant coating (FR-CPCM) is proposed, which is placed between batteries to prevent thermal runaway (TR) propagation. The CPCM with 40 wt.% paraffin (PA) and 60 wt.% silica aerogel (SA) achieves the lowest thermal conductivity of 0.051 W/(mK) at the density of 424 kg/m(3). After coated, the FR-CPCM performs the V-0 rating at UL-94 test and 56.31% of limiting oxygen index, as well as a good insulation performance under the nearly 700 C side heating test. The thermal runaway (TR) tests of battery modules show that the addition of FR-CPCM between batteries can effectively prevent the propagation of battery TR, and keep the maximum external temperature of the adjacent battery below 182.6 C. While TR in module without FR-CPCM propagated to its adjacent one in only 63 s. Moreover, FRCPCM exhibits good compressive performance, which will not crack even under the pressure of 40 MPa. The above results indicate that FR-CPCM is promising in the application of safer battery systems.

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