Cucurbit(7)uril-engineered expanded graphite-encapsulated eutectic hydrated salt composite phase change material for battery thermal management

With the rapid development of new energy vehicles, heat accumulation in lithium-ion batteries (LIBs) under high-power operation has become a critical challenge. Here, a eutectic hydrated salt system comprising disodium hydrogen phosphate dodecahydrate (DHPD) and sodium carbonate decahydrate (SCD) was encapsulated in cucurbit[7]uril (CB[7])-modified expanded graphite (EG) to develop a composite phase change material (C/E@DS) for battery thermal management (BTM). CB[7] improves interfacial compatibility and nucleation behavior, enhancing overall thermal performance. C/E@DS exhibits a suitable phase change temperature (36.1°C), high latent heat (147.6 J/g), enhanced thermal conductivity (3.94 W/m·K), excellent leakage resistance, and stability over 400 thermal cycles. Simulated battery heating tests demonstrate that C/E@DS consistently suppresses battery temperature under different ambient conditions, achieving a maximum temperature reduction of 4.45°C. These results demonstrate the potential of C/E@DS for efficient and reliable BTM.