US Patent 10193181 Pressurization device for battery cells

A pressurization device has a housing accommodating a plurality of battery cells and a plurality of spacers fixed to housing at even intervals in the thickness direction and forming bag shapes capable of expanding and contracting in accordance with air pressure. In a state in which the spacers have been contracted, each space larger than the dimensions of the battery cells in the thickness direction is maintained between adjacent spacers. In a state in which the spacers have been expanded by increasing the air pressure inside the spacers by an air apparatus, the adjacent spacers pressurize the battery cells in the thickness direction.