Abstract:

For the problem of performance degradation in LiFePO₄ batteries under low-temperature conditions， a lightweight， high-strength， low-voltage， safe， and energy-efficient Fiber Carbon-nanotube film Laminated heating structure for LiFePO₄ battery is designed and developed， and experimental validation is conducted. The thermocompression technology is used to achieve the integrated molding of the Carbon-nanotube film and composite laminated structure. The experiment verifies the uniformity， stability and thermal fatigue resistance of a FCL （Fiber Carbon-nanotube film Laminated composite） heater. Furthermore， heating experiments on LiFePO₄ batteries in low-temperature environments are carried out， which is compared with the traditional Positive Temperature Coefficient （PTC） heater. The results show that compared to the traditional PTC heater， the FCL heater exhibits a 59% reduction in weight， a 3.5% decrease in energy consumption， a 26% improvement in temperature rise efficiency， and a 195% increase in power-to-weight ratio.

Key words: LiFePO₄ battery, fiber carbon-nanotube film laminated composite, low temperature resistance, functional structure