A heating method combining AC pulse heating with electrothermal film

Battery heating at subzero temperature is important for electric vehicles in northern winter, and alternative current (AC) pulse heating is with less energy loss and more efficient for it. However, AC pulse heating makes inhomogeneous temperature distribution in battery module. Therefore, a heating method combining AC pulse heating with electrothermal film is proposed in this paper: (1) AC pulse heating with different current amplitudes (1C, 2C, 2.5, 3C) and excitation frequencies (10Hz, 30Hz, 50Hz, 80Hz) are analyzed in 4P6S cylindrical lithium-ion battery module. And the appropriate heating parameters are found, which can heat the module from -25°C to near 0°C in 600s. (2) Then, the electrothermal film is added to AC pulse heating in 10A with different current amplitudes (10Hz, 30Hz, 50Hz) to achieve homogeneous temperature distribution. And the maximum temperature difference is reduced from 2.95 °Cto 0.71°C, which demonstrates the temperature uniformity is significantly improved.