Introducing a flexible insulation network to the expanded graphite-based composite phase change material to enhance dielectric and mechanical properties for battery thermal management

作者：Yang, Kaixin; Ling, Ziye^*; Fang, Xiaoming; Zhang, Zhengguo^*

来源：Journal of Energy Storage, 2023, 66: 107486.

DOI：10.1016/j.est.2023.107486

• Composite phase change materials
• Natural rubber network
• Flexible insulation network
• Dual encapsulation
• Battery thermal management

Expanded graphite (EG)-based composite phase change materials (PCMs) are often applied in battery thermal management due to their excellent thermal and leakage-proof performance. However, the high electrical conductivity and poor adaptability have become critical limitation. Herein, a novel composite phase change material (CPCM) with high resistivity and flexibility is synthesized for extensive battery thermal management. Natural rubber formed a flexible insulation network between expanded graphite and OP44E PCM. The CPCM possesses a high energy storage density (156.5 J/g), high improved resistivity (2700 Omega.cm), and excellent thermal conductivity (3.4 W/m.K). Moreover, the flexibility and shape adaptability properties of the CPCMs can be achieved at room temperature and are especially promoted when the phase change occurs. The resultant CPCMs show high efficiency and reliability of thermal management by keeping the operating temperature of the battery pack within 45 degrees C and temperature difference within 2 degrees C under 3 C high-rate discharge cycles. Our works provide a promising choice for efficient heat-related applications.