Power battery heat management device and heat management method

The invention relates to the field of power batteries and aims to provide a power battery heat management device and a heat management method. The power battery heat management device comprises a battery box, a power battery mounted in the battery box and formed by a plurality of battery modules, a temperature sensor, a magnetic material ring, a magnetic material ring rotating device, an electromagnet, a cooling device and a controller, the temperature sensor, the magnetic material ring and the magnetic material ring rotating device are arranged on the outer sides of the battery modules, and the electromagnet, the cooling device and the controller are arranged outside the battery box; a through hole is formed in one side of the battery box, the magnetic material ring is positioned in the battery box, one side of the magnetic material ring penetrates the through hole to extend outside the battery box, the electromagnet is opposite to one side, extending outside the battery box, of the magnetic material ring, a