Dual-strategy-encapsulated phase change materials with thermal immune functions for efficient energy storage and all-climate battery thermal management

The utilization of phase-change materials (PCMs) has garnered great interest in purposes of energy storage and thermal management due to its lightweight, high-energy efficiency, and cost-competitiveness. However, the intrinsic limitations of low thermal conductivity and leakage in PCMs impede their usage in high-power-density energy harvesting applications. Here, we designed multifunctional phase-change composites (PCCs) via a dual-encapsulation strategy to realize all-climate thermal managements for lithium-ion batteries. For PCMs, polyethylene glycol was interpenetrated into porous polyurethane network (PEG@PU) to enclose a considerable amount of PEG. Then, the PCMs were infiltrated into the highly oriented graphite frameworks (HOGF). A series of processes enabled to form multi-layered structures as well as alleviate the leakage issue of PEG, and thereby improving the thermal storage ability. The so-obtained PCCs exhibited excellent electrothermal properties (134.9 °C at 1.8 V) and high electromagnetic interference performances (larger than 90 dB). These findings presented that the thermal managements of PCCs can be utilized as active preheating or passive cooling system in a battery thermal management system for the all-climate demands.