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.