POWER SUPPLY DEVICE, ELECTRIC VEHICLE COMPRISING SAID POWER SUPPLY DEVICE, AND POWER STORAGE DEVICE

In order to efficiently radiate heat generated by a battery cell by a lower plate, power supply device (100) includes: battery stack formed by stacking a plurality of battery cells (1); a pair of end plates disposed at both ends of the battery stack; binding bars configured to connect the pair of end plates; lower plate (16) that is brought into contact with heat radiation surfaces (1X) of battery cells (1) forming the battery stack and to which heat energy of battery cell (1) is transferred; and heat conductive sheet (17) having plasticity and stacked on a surface of lower plate (16). In lower plate (16), contact surface (16a) that is brought into contact with heat conductive sheet (17) is regular uneven surface (16X), heat conductive sheet (17) is stacked on uneven surface (16X) in a pressed state, heat conductive surface (17X) of heat conductive sheet (17) is deformed into a concave shape along uneven surface (16X), and heat conductive sheet (17) and lower plate (16) are stacked on each other in a contact state.