Enhancement of thermal management performance in lithium-ion batteries using biomass-derived carbon-enhanced phase change materials

Thermal management is critical for ensuring the safety and performance of lithium-ion batteries (LIBs). This study presents a novel composite phase change material (CPCM) synthesized using biomass-derived carbon from U ndaria pinnatifida and expanded graphite to enhance the thermal performance of paraffin wax (PW). The developed CPCM exhibits a thermal conductivity of 0.89 W/(m·K), 4.24 times higher than pure PW, while effectively preventing melting leakage. Numerical simulations demonstrate the CPCM can reduce the peak battery temperature from 77.7 °C to 59.7 °C at a 3C discharge rate and maintain temperature uniformity within 5 °C. Optimization of thermal conductivity enhancement and battery spacing reduction further improved heat dissipation and phase change utilization efficiency, highlighting the critical role of material properties and pack geometry in thermal management. This study establishes a sustainable and effective pathway for improving the safety of LIBs using biomass-derived materials, addressing key challenges in energy storage.