Experimental investigation on a Fiber Carbon-nano Laminated heater to improve LiFePO₄ battery performances under low-temperature conditions

Abstract LiFePO 4 batteries play a vital role in electric vehicles (EVs). However, LiFePO 4 batteries are significantly affected by low temperatures. In this research, a lightweight, efficient, low-voltage, and safe Fiber Carbon-nano Laminated (FCL) heater for LiFePO 4 batteries is designed, developed, and experimentally validated. Experiments are conducted to heat LiFePO 4 batteries under -20°C and compared with traditional Positive Temperature Coefficient (PTC) heaters. The results demonstrate that the FCL heater exhibits stable heating performance with uniform temperature distribution within the heating area. Heating for 45 minutes can raise the temperature of a LiFePO 4 battery module from -15°C to 0°C, consuming 128.2 Wꞏh, approximately 2.7% of the battery module’s capacity. Compared to traditional PTC heaters, the FCL heater shows significant advantages: a 65.6% reduction in supplied voltage, a 59% decrease in weight, a 21.4% increase in power, a 3.5% decrease in energy consumption, a 26.0% improvement in temperature rise efficiency, and a 195% increase in power-to-weight ratio.