摘要 |
The battery pack of the present invention includes a bipolar secondary battery used as a power source of a vehicle, and a cooling passage allowing flow of a cooling medium. The cooling passage is integrated with a casing. The cooling passage includes an inlet passage provided along that one of a plurality of battery modules which is positioned at one end of the plurality of battery modules for introducing the cooling medium from an input port, an outlet passage provided along that one of the plurality of battery modules which is positioned at the other end of the plurality of battery modules for discharging the cooling medium from an outlet port, and a direction changing portion provided between the inlet passage and the outlet passage changing the flow direction of cooling medium coming from the inlet passage and passing the cooling medium to the outlet passage. According to the present invention, the cooling medium is discharged to the same side as the introducing side. Specifically, the direction of cooling medium flowing in the inlet passage is opposite to the direction of cooling medium flowing in the outlet passage. As the cooling medium is caused to flow in this manner (a so-called counter flow method), temperature distribution in bipolar secondary battery can be made uniform. |