A novel preheating method for the Li-ion battery using supercooled phase change materials

• Published in: Science China. Technological sciences 2023, Vol.66 (1), p.193-203
• Main Authors: Fang, XuanYi, Nong, XinLu, Liao, ZhiRong, Xu, Chao
• Format: Article
• Language: English
• Subjects: Electric vehicles; Energy storage; Engineering; Hand tools; Heating; Height; Lithium-ion batteries; Low temperature; Phase change materials; Rechargeable batteries; Sodium acetate; Storage systems; Supercooling; Temperature; Thermal energy; Thermal management; Thickness
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-022-2209-9

The Li-ion battery is widely used in power tools, energy storage systems, and electric vehicles. In reality, battery thermal management is essential to control the battery temperature within a specific temperature range. Although research has shown that preheating the battery at low temperatures on cold days can improve output performance significantly, few efforts have been made to study the preheating method in-depth As a result, this research proposes two preheating designs for cylindrical batteries with supercooled phase change materials: Single- and dual-phase change material (PCM) designs. A mathematical model is developed to analyze the effect of the PCM layer’s height, thickness, and mass on the preheating effect for seven candidate PCMs with high supercooling degrees. Furthermore, the economic efficiency of the single-PCM design with different PCMs is compared. In addition, the optimal ratio of the PCMs’ height for the dual-PCM design is investigated. Eventually, the improvement of the battery’s output performance is discussed. The results reveal that the proposed designs can effectively preheat the battery with a temperature rise higher than 10°C. The single-PCM design using LiNO 3 ·3H 2 O shows the best preheating ability, while CH 3 COONa·3H 2 O is the most economical. Although the dual-PCM design cannot outperform the single-PCM design, it can preheat the battery twice and show better flexibility. Compared with the battery without preheating, a 26650-format battery with the single-PCM design can prolong the operating time by 38.8 min and save the electric quantity by 2.1 A h; while they are by 42.8 min and 2.3 A h with the dual-PCM design.