Energy storage module

1. An energy storage module comprising:

a plurality of battery cells arranged in a length direction such that long side surfaces of adjacent battery cells of the battery cells face one another;

a plurality of insulation spacers, at least one of the insulation spacers being between the long side surfaces of each adjacent pair of the battery cells;

a cover member comprising an internal receiving space configured to accommodate the battery cells and the insulation spacers;

a top plate coupled to a top of the cover member, the top plate comprising ducts respectively corresponding to vents of the battery cells and having opening holes respectively corresponding to the insulation spacers;

a top cover coupled to a top of the top plate and having discharge holes respectively corresponding to the ducts; and

an extinguisher sheet between the top cover and the top plate, the extinguisher sheet being configured to emit a fire extinguishing agent at a temperature exceeding a reference temperature,

wherein the top cover comprises protrusion parts on a bottom surface thereof, the protrusion parts covering an exhaust region and being coupled to an exterior of each of the ducts, and each of the insulation spacers comprises a flame-retardant or non-combustible first sheet and heat-insulating second sheets respectively adhered to opposite surfaces of the first sheet by an adhesion member.

2. The energy storage module of claim 1 , wherein the first sheet comprises ceramic paper, and the second sheets comprise mica paper.

3. The energy storage module of claim 1 , wherein the first sheet comprises a ceramic fiber comprising an alkali earth metal.

4. The energy storage module of claim 1 , wherein the long side surfaces of the adjacent battery cells are spaced apart from each other by a first distance, and

wherein a thickness of each of the insulation spacers is less than 50% of the first distance.

5. The energy storage module of claim 1 , wherein when the fire extinguishing agent is emitted from the extinguisher sheet, the fire extinguishing agent is applied to spaces between the insulation spacers and the battery cells through the opening holes to be brought into contact with the long side surfaces of the battery cells.

6. The energy storage module of claim 1 , wherein each of the insulation spacers has a width-direction size less than twice a height-direction size thereof and comprises a sheet part comprising the first sheet and the second sheets adhered to each other at opposite ends thereof by the adhesion member.

7. The energy storage module of claim 6 , wherein each of the insulation spacers further comprises an edge part made of a plastic material, the edge part being formed by insert molding to cover peripheral edges of the sheet part.

8. The energy storage module of claim 6 , wherein the first sheet and the second sheets are spaced apart from each other at central portions thereof to define air passages to allow for air movement.

9. The energy storage module of claim 1 , wherein a width-direction size of each of the insulation spacers is greater than twice a height-direction size thereof, and

wherein the first sheet and the second sheets respectively comprise regions adhered to each other by the adhesion member.

10. The energy storage module of claim 1 , wherein the top cover further comprises an inclined part to have a gradually increasing thickness from the exhaust region to the protrusion part.

11. The energy storage module of claim 10 , wherein a top end of each of the ducts is located below the inclined part.

12. The energy storage module of claim 10 , wherein a space is defined between each of the ducts and a corresponding one of the protrusion parts, and some of the gas discharged through each of the vents moves to the respective space via the duct and the inclined part.

13. The energy storage module of claim 1 , wherein each of the ducts tapers away from a bottom portion thereof with an inner diameter thereof gradually decreasing upwards.

14. The energy storage module of claim 1 , wherein an overall area occupied by the discharge holes is not less than about 30% of an area of the exhaust region.