Heat transfer characteristics and low-temperature performance of a lithium-ion battery with an inner cooling/heating structure

Abstract

To improve heat dissipation and low-temperature performance, the paper presents a novel lithium-ion battery with an inner cooling/heating structure. A copper pipe with an internal heater strip is inserted into the battery to enhance its heat dissipation capability and heat it from the inside at low temperatures. To verify the novel battery's performance, a sample battery is prepared and its heat transfer characteristics at 25 °C and discharge performance at −20 °C are experimentally researched. The results show that the battery's heat transfer characteristics and low-temperature performance can be significantly improved by the inner cooling/heating structure. For the heat dissipation characteristics, compared with the original battery, at 25 °C, the peak external temperatures of the sample battery are reduced by 0.6 °C and 1.4 °C under 1 C charge rate and 1.5 C discharge rate conditions, respectively. For the low-temperature performance, the battery discharge performance can be comprehensively improved by the strategy of preheating and simultaneous heating. Under −20 °C and 1 C discharge rate conditions, compared with the battery without heating, using 3.70 W preheating and simultaneous heating power, the discharge capacity and initial discharge voltage of the battery are increased by 46.0 % and 0.66 V, respectively.