Patent attributes
Disclosed herein is a middle- or large-sized battery pack including a plurality of unit cells electrically connected with each other, wherein the battery pack is constructed in a structure in which a heat transfer medium flows through gaps defined between the unit cells for controlling the overall temperature of the battery pack to be within a predetermined temperature range for the optimum operation of the battery pack, and each unit cell is provided at the outer surface thereof, at which the heat transfer medium is brought into contact with each unit cell, with a layer containing a phase transformation material (‘phase transformation layer’) for minimizing individual temperature difference between the unit cells. The present invention has the effect of controlling the overall temperature of the battery pack and individual controlling the temperatures of unit cells constituting the battery pack. Also, the present invention has the effect of restraining the abrupt change in temperature of the unit cells, when the battery pack is not in operation or when the external environment abruptly changes, thereby preventing the degradation of the unit cells. Furthermore, the present invention has the effect of minimizing damage to the unit cells due to foreign matter when the foreign matter is brought into contact with the unit cells. In addition, the present invention has the effect of reducing the overall temperature difference of the battery pack and manufacturing a middle- or large-sized battery pack having a compact structure.
