Recyclable Phase Change Materials with Wide-Temperature Flexibility and Electrical Insulation for Battery Thermal Management

Phase change materials (PCMs) have garnered significant attention in battery thermal management. Reliable thermal safety management requires close contact between PCMs and batteries, yet current designs lack the desired flexibility and insulation to prevent detachment and short circuit. The recycling and reuse of decommissioned PCM is also a concern. Here we design a recyclable flexible composite PCM (FCPCM) with wide-temperature flexibility and excellent electrical insulation to address these challenges. The FCPCM demonstrates flexibility ranging from −15 to 60 °C, a volume resistivity of 9.2 × 1010 Ω·cm, and a phase change enthalpy of 126.2 J/g. The 10th recycled FCPCM maintains its original mechanical and phase change properties, exhibiting excellent recyclability. It can be seamlessly integrated with batteries at room temperature, providing reliable thermal management capabilities. At 4 C discharge rate, the maximum temperature of the FCPCM-wrapped battery decreased by 31.4 °C compared to a bare one, and increased by less than 1.8 °C after 10 h of vibration. Moreover, both the maximum temperature and the maximum temperature difference of the FCPCM-wrapped battery module (comprising 6 batteries) remained within the safe range after 10 cycles. The demonstrated effectiveness and reliability ensure great practical prospects for the proposed FCPCM in battery thermal management.