Polyurethane Foam Skeleton-Based Phase Change Hydrogel for Efficient Battery Thermal Management with Favorable Antivibration Performance.

Efficient thermal management is critical to ensure the safe and reliable operation of lithium-ion batteries (LIBs) as they are highly sensitive to temperature changes. Meanwhile, LIBs are exposed to various external forces during operation, such as vibration, shock, and oscillation, which may disrupt the physical and chemical processes inside the battery and lead to a decreased performance and shortened life. Here, we designed a phase change hydrogel (PCH) pad based on the polyurethane (PU) foam skeleton and demonstrated its effectiveness in efficient thermal management and improving antivibration performance. The thermal conductivity of the prepared composite is 0.65 W/(m·K), while the thermal contact resistance could decrease to ∼20 K·cm2/W under 60 °C. It exhibits a flexible contact transformation during the phase transition, resulting in enhanced interfacial heat transfer and storage rate, as well as improved resistance against external impacts. The temperature of the battery module wrapped with a composite plate decreases by 11.4 °C during the 6C discharge. Moreover, the additional heat generated by external vibration is only half that of the bare battery, and the temperature difference could reach 5.2 °C, demonstrating the effective buffering effect of PCH@PU in mitigating long-term discharge-induced increases in internal resistance. The developed PCH@PU, known for its exceptional thermal management and favorable antivibration performance, holds promising potential for widespread utilization in the field of power battery heat dissipation.

Effects of pendant side groups on the properties of the silicon-containing arylacetylene resins with 2,5-diphenyl-[1,3,4]-oxadiazole moieties.

Silicon-containing arylacetylene resins with rigid conjugated structures in the main chain often exhibit poor processability. A strategy of improving the processability by destroying the molecular structure symmetry using side aromatic groups was proposed, and the effects of the side groups was further explored. Two novel structural resins with side aromatic phenyl and phenylacetylene groups (PODSA-2P-MM and PODSA-2E-MM) were synthesized by Grignard reaction. The side aromatic groups strongly interfere with the regular arrangement of the main chains, and the crystallinities of the resins decrease as compared with PODSA-MM resin without side aromatic groups. Due to the influence of the side aromatic groups, the novel resins exhibit good processability, low exothermic enthalpy, high modulus and good heat resistance.