Shape-stable MOFs-based composite phase change materials for enhanced thermal management in Li-ion batteries

MOF-based composite phase change materials (CPCM) have been developed as promising solutions for the thermal management of lithium-ion batteries to maintain suitable temperatures. Nevertheless, the discrepancy in the thermal management performance of various MOFs-based and MOFs-derived carbon-based CPCMs awaits investigation. In this work, CPCMs were synthesized by combining polyethylene glycol, polyvinylpyrrolidone, and expanded graphite with three large production metal-organic frameworks, including ZIF-8, Al-fumarate, MIL-101(Cr), whose pore size gradually increased, and their derived carbons. All the CPCMs exhibited excellent shape stability, high thermal stability, and enhanced thermal conductivity, while MIL-101(Cr) exhibited overstrong nanoconfinement effects, leading to the decrease of enthalpy during the phase transition. However, after carbonization, CPCM-MIL-101(Cr)-C achieved the highest melting enthalpy of 99.0 J g−1 and a higher proportion of ordered carbon domains that enhanced thermal properties. Battery tests under different discharge rates and long-term discharge-charge cycles showed that the CPCMs effectively reduced the peak temperatures of the battery surface even at 5C discharge rate. Economic analysis of such large-production MOFs revealed that CPCM-ZIF-8 was the most cost-effective at moderate discharge rates, while CPCM-MIL-101(Cr)-C was better under extreme conditions of 5C. This study provides a comprehensive evaluation of MOF-based and MOF-derived carbon-based CPCMs for Li-ion battery thermal management, highlighting their practical potential in the battery thermal management field.