Thermal management study of cylindrical battery using novel thermally conductive anisotropic flexible phase change material

As high density electronic-energy units, cylindrical lithium-ion batteries face significant thermal runaway risks. To address this concern, we developed a novel phase change thermal management strategy through design of phase change materials (PCM) with superior thermal performance: graphene-derived carbon aerogel (CA) with optimized oriented porous networks were synthesized as three-dimensional thermal conduction skeleton to overcome the low thermal conductivity of pure PCM matrix. Meanwhile, olefin block copolymer (OBC) with excellent elasticity was regarded as the flexible supporting material to co-melt with PCM matrix, endowing the PCM with flexibility to match the application requirement of the cylindrical battery with great hardness. Then the anisotropic flexible PCM (FPCM) was prepared and obtained. The test results showed that the radial and axial thermal conductivities of FPCM reached 6.75 W/(m·K) and 2.92 W/(m·K), respectively. At a battery heat generation density of 2.9×10 5 W/m 3 , the effective thermal control duration of the FPCM is extended by 471 s compared to existing isotropic PCM. Additionally, comparative evaluations revealed that the FPCM configuration with 4 mm thickness and radial thermal conductivity of 6.04 W/(m·K) exhibited the most effective temperature controlling, successfully achieving the battery surface temperature drop by 13.1 °C during operation. • Novel FPCM is prepared for cylindrical battery thermal management. • ·Highly anisotropic thermally conductive networks are architected in FPCM. • ·FPCM improves radial/axial thermal conductivities by 32 and 13 times. • ·FPCM extends effective thermal control time by 421s compared to isotropic PCM. • ·Optimal 4mm-thick FPCM decreases battery surface temperature by up to 13.1 °C.