Ultrareliable Composite Phase Change Material for Battery Thermal Management Derived from a Rationally Designed Phase Changeable and Hydrophobic Polymer Skeleton

Abstract

The development of phase change material (PCM) for battery thermal management poses key limitations on its reliability caused by leakage and shape deformation under high temperature. In this work, a kind of phase changeable and hydrophobic polymer skeleton is grown in situ in a paraffin (PA)/expanded graphite matrix to obtain the leakage-proof composite PCM (CPCM) at the kilogram-level. Benefiting from the additional latent heat provided by the phase changeable alkyl side chains of the polymer skeleton, the obtained CPCM shows a high latent heat of 120.3 J g–1 coupled with a thermal conductivity of 2.92 W m–1 K–1. Most importantly, the three-dimensional cross-linking main chain and the hydrophobic alkyl side chains endow the obtained CPCM with extraordinary shape stability under high temperatures up to 250 °C and high PA adsorbing capability, respectively. As a consequence, the CPCM presents excellent antileakage performance for the battery module (21 V/16 Ah) under harsh working conditions, i.e., 50 charge–discharge cycles at 3C–4C, thus giving rise to a durable cooling performance. The maximum temperature (T max) and temperature difference (ΔT max) of the battery module can be controlled constant at 50.9 and 5.0 °C during the cycles, respectively. By stark contrast, owing to the obvious leakage phenomenon, the battery module with traditional CPCM adopting a classical low-density polyethylene skeleton shows increasing T max and ΔT max during the cycles.

Investigation of the thermodynamic properties of hydrates as cooling phase change materials for their implementation in electric vehicles

“…Paraffins, fatty acids, alcohols, esters and glycols are known organic PCMs. [7][8][9][10] However, their low thermal conductivity (0.1-0.35 W m À1 K À1 ) and flammability make them less effective and bring safety concerns. 11,12 Metallic PCMs are attractive because of their high thermal conductivity 13 and higher heat capacity than organic PCMs.…”

Experimental study on the hybrid carbon based phase change materials for thermal management performance of lithium‐ion battery module

“…Tian et al 36 prepared the CPCM with EG and CF, which have an obvious synergistic enhancement action on the heat conduction capacity of PCM. Xiao et al 37 established a CPCM with a new thermosetting hydrophobic polymer (THP) skeleton, which could stably control the maximal temperature and maximal temperature difference at 50.9°C and 5.0°C, respectively, under 50 continuous cycles of 3 C and 4 C charge‐discharge. Li et al 38 prepared the CPCMs by adding grafted CNTs, and found that compared with adding ungrafted CNTs, it had better dispersion and heat conduction capacity.…”

Preparation of Composite Cooling Boards Composed of Thermal Conductive Silica Gel and Phase Change Materials for Battery Thermal Management

“…During the long-term operation, the liquid-state PCM may gradually migrate onto the module surface, leading to the degradation of the thermal storage capacity of the CPCM module or even causing safety issues. For example, Xiao et al prepared a classical PA/EG/low-density polyethylene CPCM and observed a significant mass loss during 100 endothermic–exothermic cycles within the temperature range of 30–70 °C; Lin et al prepared a PA/EG/olefin block copolymer-based CPCM and found a leakage rate of more than 1 wt % in a vacuum drying oven at 60 °C. Furthermore, the rigid property of both the cells and the CPCM results in a rigid contact at the interface, which gives rise to a relatively high thermal contact resistance and compressive stress accumulation during complex driving conditions …”