Power supply device, and electric vehicle and power storage device that comprise said power supply device

A power supply device comprising:

• a battery block including a plurality of battery cells stacked in a thickness with a separator clamped between each adjacent pair of the plurality of battery cells;
• a pair of end plates disposed on opposing end faces of the battery block;
• and
• a binding bar coupled to the pair of end plates to fix the battery block in a compressed state via the end plates,
• wherein the separator includes a three-layer structure including (i) an elastic sheet that is viscoelastic and absorbs expansion of the adjacent pair of the plurality of battery cells, and (ii) (iii) heat-insulating sheets laminated on opposing surfaces of the elastic sheet,
• each of the heat-insulating sheets includes a hybrid material of an inorganic powder and a fibrous reinforcing material, and
• wherein each of the plurality of battery cells includes a battery case whose upper end opening is closed with a sealing plate, and
• the separator includes the elastic sheet disposed in a body region, the body region not including a sealing part region clamped at an upper end of the battery case between the adjacent pair of the plurality of battery cells.