Copper foam reinforced polymer-based phase change material composites for more efficient thermal management of lithium-ion batteries

In this study, copper foam reinforced polymer-based composite phase change materials (CPCM) were prepared to solve the problems of low thermal conductivity , melting leakage, and poor mechanical strength in the realistic application of phase change materials. The CPCM consists of paraffin (PA) and styrene-ethylene-butylene-styrene (SEBS). Stability and mechanical tests were conducted and it was found that CPCM-90 (with a mass fraction of PA at 90 %) exhibited excellent leakage protection ability, shape stability, and bending resistance. The enthalpy of CPCM-90 is up to 168.11 J/g. After filling CPCM into copper foam (CF) with 98 % porosity, the thermal conductivity of the CF/CPCM-90 is improved up to 0.943 W/m·K, nearly 3 times higher than the thermal conductivity of CPCM-90. In addition, the reinforcement of copper foam allows CF/CPCM-90 before and after the phase transformation to withstand mechanical stress of 2 MPa and 0.7 MPa respectively with only 1 % strain. The CF/CPCM-90 also maintained its structural integrity during phase transformation, distinguishing it from CPCM, which commonly experiences cracking and deformation. Furthermore, CF/CPCM-90 maintains battery temperatures below 60 °C for 70 min at 7 W of heat generation and 34 min even at 13 W. Notably, at all heating powers, the duration below 60 °C of the CF/CPCM group is 3 times longer than in the copper foam group and 4 times longer than in the control group (no CF/CPCM-90 or CF). The CF/CPCM-90 shows very effective temperature control for LIBs and has great potential for realistic application regarding battery thermal management . Moreover, this paper provides ideas for further engineering applications of phase change materials in terms of synergistic enhancement of thermal conductivity, leakage prevention, and mechanical properties.