Cell assembly having cushion member

1. A cell assembly comprising:

an upper outer frame and a lower outer frame spaced from the upper outer frame in a first direction;

a plurality of cells arranged between the upper outer frame and lower outer frame at predetermined intervals; and

cushion pad disposed between two of the plurality of cells to make a surface contact with the cells and configured to absorb volumetric expansion of the cells,

wherein a top edge of the cushion pad is in continuous contact with the upper outer frame and a bottom edge of the cushion pad is in continuous contact with the lower outer frame, the top edge of the cushion pad and the bottom edge the cushion pad being spaced from each other in the first direction,

wherein the cushion pad has a thermal conductivity of 1.5 W/mK or higher, and

wherein the cushion pad is made of foam material.

2. The cell assembly of claim 1 , wherein the cushion pad is formed of a plate-shaped body having at least an area equal to or greater than an area of a planar portion of the cells, and

wherein a flat portion of the cushion pad is in surface contact with the planar portion of the cell.

3. The cell assembly of claim 1 , wherein an area of a planar portion of the cushion pad is less than 105% of the area of the planar portion of the cells.

4. The cell assembly of claim 1 , wherein a thickness of the cushion pad is 120% to 250% of a volumetric expansion ratio of the cells.

5. The cell assembly of claim 4 , wherein a thermal conductivity of the cushion pad is 1.5 W/mK to 1.6 W/mK.

6. The cell assembly of claim 1 , wherein the cushion pad is formed of polydimethylsiloxane.

7. The cell assembly of claim 1 , wherein the cushion pad is formed of a material that is both an incombustible (fire retardant) material of UL94 V-1 or higher and an insulating material of 10 kV/mm or higher, and has a compression force deflection (CFD) of 20 kPa to 100 kPa in a section with 20% to 60% of strain.