Wensheng Yang,Ruheng Lin,Xinxi Li,Canbing Li,Yuhang Wu,Guoqing Zhang,Xiaozhou Liu,Songbo Li,Yongzhen Wang
The thermal safety of battery module is demonstrated as the main bottleneck to hinder wider adoption of electric vehicles (EVs). It is vital to explore efficient thermal management system to satisfy the rapidly increasing need for EVs. Composite change materials (CPCMs) as passive cooling system has greatly potential application in battery packs. However, the inherent leakage and low thermal conductivity are restricted its widely utilized in practical applications. In this study, the high thermal conductivity CPCM with PEG/EG/HNT@AP has successfully prepared through a synergistic method of in situ chemical reduction and physical blending technology. Polyethylene glycol (PEG) as the phase change matrix and halloysite nanotube (HNT) as the support material can provide cross-linked network to prevent its leakage. Especially, the expanded graphite (EG) and silver nanoparticles (AgNPs) assembled into HNT (HNT@AP) play a synergistic role to construct an interconnected thermal network. The results indicates that the thermal conductivity is increased to 1.15 W·m −1 ·K −1 and the latent heat of phase change can maintain to 103.65 J·g −1 , when the content of HNT@AP is 40 %. In addition, the battery module with PEG/EG/HNT@AP and PEG/EG/ER are designed and measured during charge and discharge cycling process, respectively. It reveals that battery module with PEG/EG/HNT@AP can exhibit excellent thermal management effect, which temperature was controlled below 60 °C at 3C discharge rate even under 35 °C ambient temperature. Therefore, this work sheds light on rational design of high thermal conductive composite material to improve thermal safety of battery pack in the EVs.
Qinxian Ye,Peng Tao,Chao Chang,Linye Zhou,Xiaoliang Zeng,Chengyi Song,Wen Shang,Jianbo Wu,Tao Deng
The heat packs that are based on solid–liquid transition of phase-changing materials (PCMs) have been pursued as a promising way to provide heating for human body comfort and thermotherapy owning to their large heat storage capacity and near-constant heat-release temperature. Current heat packs, however, suffer from leakage, slow charging, and poor heat-release performance due to the flow of liquid PCMs and their low thermal conductivity. Here, we report a strategy for preparing high-performance PCM-based solar thermal heat packs through impregnating organic PCMs within carbon-coated copper foams (CCFs). The porous structure and hydrophobic surface of CCF help to effectively confine the melted liquid PCM within the composite heat pack without leakage. The carbon coating layer efficiently converts the incident solar light into heat, which is rapidly transferred along the three-dimensional thermal conductive network of CCF and stored within the PCM. In the discharging process, the CCF network facilitates the extraction of the heat stored within the PCM. In contrast to neat PCM pack within which only a small portion of PCM that is in contact with human skin contributes to thermal comfort, all PCMs within the CCF-based composite heat pack concertedly release the stored heat. Such release significantly increases the extractable thermal energy and prolongs the usable healing duration for thermotherapy.