Power storage device

1. A power storage device, comprising:

a power storage stack which includes a plurality of power storage cells aligned in a given alignment direction;

a heating member that is deformable to follow steps between the plurality of power storage cells and heats the power storage stack;

a cooling member that is deformable to follow the steps between the plurality of power storage cells and has a refrigerant flow passage through which a refrigerant for cooling the power storage stack flows;

a first pressing member that presses the heating member against the power storage stack;

a second pressing member that presses the cooling member against the power storage stack; and

a sheet member covering a bottom of the power storage stack so that an enclosed space is formed between the sheet member and the power storage stack in a cross section of the power storage stack perpendicular to the alignment direction, wherein

the sheet member has a first surface and a second surface which are in opposing relation, the first surface facing the power storage stack, the second surface facing opposite the power storage stack,

the cooling member is disposed on a first surface side, within the enclosed space, and

the heating member is disposed on a second surface side, on an outer side of the enclosed space.

2. The power storage device according to claim 1 , wherein

the sheet member is sandwiched between the power storage stack and the heating member by a pressing force by the first pressing member.

3. The power storage device according to claim 2 , wherein

the plurality of power storage cells each include a case having a bottom surface and accommodating a power storage element, and a frame covering the bottom surface of the case,

the frame has a notch through which a portion of the bottom surface of the case facing the cooling member is exposed, and

the cooling member is pressed against the portion of the bottom surface exposed through the notch.

4. The power storage device according to claim 3 , wherein

a thermal conductive sheet is disposed between the cooling member and the portion of the bottom surface exposed through the notch, the thermal conductive sheet being electrically insulative.

5. The power storage device according to claim 1 , wherein

an elastic modulus of the second pressing member pressing the cooling member is greater than an elastic modulus of the first pressing member pressing the heating member.

6. The power storage device according to claim 1 , wherein

the power storage stack includes a first end portion and a second end portion in a direction perpendicular to the alignment direction,

the first pressing member includes a first press disposed on a first end portion side and a second press disposed on a second end portion side,

the second pressing member is disposed between the first press and the second press in the direction perpendicular to the alignment direction,

the power storage device further comprising: a first mount portion on which the first press is mounted, a second mount portion on which the second press is mounted, and a third mount portion on which the second pressing member is mounted, wherein

the first mount portion and the second mount portion are located closer to the power storage stack than the third mount portion is, and

a pressing force by the second pressing member is greater than pressing forces by the first press and the second press.

7. The power storage device according to claim 6 , further comprising

a housing accommodating the power storage stack, wherein

a gap is provided between the first mount portion and the housing, and

a gap is provided between the second mount portion and the housing.