Showing papers by "Yutang Fang published in 2021"

Numerical analysis of battery thermal management system coupling with low-thermal-conductive phase change material and liquid cooling

Abstract: Mitigating thermal runaway propagation of batteries by applying thermal barrier to block heat transfer will inevitably weaken heat dissipation. Low-thermal-conductive phase change material (LTC-PCM) is a promising candidate of thermal barrier because of its high latent heat. While limited research is found related to how much effect does thermal barrier on performance of battery thermal management system (BTMS), especially when liquid cooling is applied. The present work compares BTMS performance of prismatic battery module with LTC-PCM, low-thermal-conductive material (LTCM), and high-thermal-conductive pad (HTCP), also further investigates BTMS performance with different width of LTC-PCM and flow rate of heat transfer fluid (HTF). The results indicate average battery temperature (Tave) in modules with the three materials follows the sequence: LTC-PCM

Experimental study on low thermal conductive and flame retardant phase change composite material for mitigating battery thermal runaway propagation

Abstract: Lithium-ion batteries (LIBs) have dominated the market in portable electronics, electric vehicles, and aerospace applications. However, safety issues greatly limit the further applications of LIBs. In this work, a low thermal conductive phase change composite material (CPCM) with flame retardant coating (FR-CPCM) is proposed, which is placed between batteries to prevent thermal runaway (TR) propagation. The CPCM with 40 wt.% paraffin (PA) and 60 wt.% silica aerogel (SA) achieves the lowest thermal conductivity of 0.051 W/(m•K) at the density of 424 kg/m3. After coated, the FR-CPCM performs the V-0 rating at UL-94 test and 56.31% of limiting oxygen index, as well as a good insulation performance under the nearly 700 °C side heating test. The thermal runaway (TR) tests of battery modules show that the addition of FR-CPCM between batteries can effectively prevent the propagation of battery TR, and keep the maximum external temperature of the adjacent battery below 182.6 °C. While TR in module without FR-CPCM propagated to its adjacent one in only 63 s. Moreover, FR-CPCM exhibits good compressive performance, which will not crack even under the pressure of 40 MPa. The above results indicate that FR-CPCM is promising in the application of safer battery systems.

Capillary performance analysis of copper powder-fiber composite wick for ultra-thin heat pipe

Abstract: Excellent ultra-thin heat pipes (UTHP) require a wick with high capillary force (ΔPc) and a good permeability performance (K). In this work, a copper powder-fiber composite wick was fabricated by sintering of the copper powder and fiber mixture. Effects of the copper powder particle size, copper powder volume ratio, as well as the super-hydrophilic treatment were investigated, and the results indicate that the copper powder volume ratio is the most significant factor by orthogonal experiments. Moreover, sensitivity analysis shows that super-hydrophilic treatment contributes the lower capillary force and higher permeability, except when copper powder particle size is high to 80 mesh and powder ratio is low to 20%. Interestingly, the overall capillary performance (ΔPc·K) of the super-hydrophilic treated wicks is significantly improved. Besides, for the super-hydrophilic treated wicks, both the smaller copper powder particle size and volume ratio contribute the higher permeability and better comprehensive performance, even though a worse capillary force.