Performance of a combined battery thermal management system with dual-layer phase change materials and air cooling technologies

Abstract

Lithium-ion batteries are increasingly applied in electric vehicles, energy storage and more. In order to ensure its stable operation under different ambient temperature, an innovative battery thermal management system (BTMS) based on phase change material (PCM) has the dual-layer PCMs arrangement is proposed in this research. To prove the effectiveness of this structure, the temperature variation of lithium-ion battery 18,650 with single PCM and dual-layer PCMs arrangement is calculated and compared by numerical simulation. The findings reveal that the dual-layer PCMs arrangement proposed in this paper has better environmental adaptability at different ambient temperatures (Tamb). When the Tamb is 20 °C and the discharge rate increases from 1C to 5C, the maximum temperature (Tmax) of the battery under the dual-layer PCMs arrangement is 25.33 °C, 30.80 °C, 33.58 °C, 35.80 °C, 39.07 °C, respectively. And in response to the high ambient temperature and high discharge rate, the dual-layer PCMs layout is combined with air cooling to form a hybrid BTMS. The results show that Tmax of the hybrid BTMS is reduced by 21.5 % compared with the PCM-based BTMS when the Tamb is 40 °C and the discharge rate is 3C. The proposed hybrid BTMS with dual-layer PCMs structure controls the Tmax of the battery pack well and the temperature uniformity is also maintained within acceptable level, which has great application potential in battery thermal management.