Preparation of Quasi‐Thermoplastic Phase Change Polymer with Intrinsic Antileakage Performance for Battery Thermal Management

Abstract

Phase change material (PCM) shows great potentials in battery thermal management (BTM) application, but there are significant challenges including PCM leakage, low secondary heat dissipation capability, and poor reprocessability. Herein, a type of phase change polymer (PCP) with intrinsic antileakage, reprocessability and heat dissipation capability is prepared via the copolymerization of octadecyl acrylate (OA) and methyl methacrylate (MMA). The rigid segment of MMA guarantees the shape stability of the PCP while avoiding using the crosslinkers, and thus simultaneously endows the linear PCP with quasi‐thermoplastic property for reprocessing. The chemical‐bonded phase changeable side chains from the OA segments provide a large latent heat of 100.5 J g–1 and fundamentally overcome the leakage problem. Additionally, the obtained PCP demonstrates a higher crystalline temperature favorable for secondary dissipation of the absorbed heat to the environment. Consequently, the obtained PCP demonstrates superior cooling performances in BTM applications. The temperature of the battery module with PCP cooling can be stably controlled below 52.5 °C under a harsh working environment of 3C‐3C charge–discharge at 35 °C for 15 cycles. In contrast, the battery module adopting classical physically blended PCM cooling shows a much higher and gradually increasing maximum temperature during the cycles.