Custom design of solid-solid phase change material with ultra-high thermal stability for battery thermal management
As an advanced battery thermal management (BTM) strategy, phase change material (PCM) cooling technology still suffers from the low thermal stability of the PCM in practical application, including the leakage of phase change ingredient and shape change or even collapse concerns under high temperature. Here we propose a creative idea of constructing cross-linking polymeric structure with aliphatic side chains, namely, polymer PCM (PoPCM), through a facile one-step free radical polymerization of octadecyl acrylate and crosslinkers. The aliphatic chains “tied up” on the cross-linking polymeric skeleton via “chemical bonding” provide a high latent heat of 98.8 J g-1 without leakage, and therefore deliver stable solid-solid phase change behavior during long-term operation. The thermosetting 3-dimensional cross-linking structure simultaneously endows PoPCM with anti-volume-expansion capability and excellent heat-tolerance, for example, withstanding 250°C without any deformation or leakage. When applied for BTM, the solid-solid PoPCM module demonstrates excellent and stable heat dissipation performance. The maximum temperature and temperature difference of the battery module can be controlled below 45.3 and 3.1°C during the cyclic charge-discharge tests, respectively. Combining with the industrial available reagents and simple preparation in kilogram level, we believe this new train of thought could present superior feasibility for the practical application of BTM.