A phase change material with enhanced thermal conductivity and secondary heat dissipation capability by introducing a binary thermal conductive skeleton for battery thermal management

In order to enhance the thermal conductivity and secondary heat dissipation capability of the phase change material (PCM) in battery thermal management (BTM) applications, a new kind of composite PCM (CPCM) is successfully prepared by constructing a binary thermal conductive skeleton of expanded graphite (EG)/copper foam (CF). The EG with porous structure can adsorb the PCM of paraffin and act as a micro-thermal-conductive framework to transfer the heat to the adjacent CF skeleton. The CF acts as a macro-skeleton to transfer the heat throughout the CPCM plate and enhance the heat transfer coefficient of the interface between the CPCM plate and air. In consequence, the obtained CPCM-based battery pack with EG/CF (CPCM-EG/CF) delivers much better cooling and temperature-uniformed performances than those without EG/CF or CF, especially under a secondary heat dissipation system of forced air convection. For example, the CPCM-EG/CF pack shows stable and lowest maximum temperature and temperature difference of 48.0 and 3.9 °C during the cycling charge-discharge tests under forced air flow, respectively.