Battery module

1. A battery module comprising:

a plurality of battery cells each having a vent;

an insulating member directly contacting the battery cells, the insulating member having a plurality of openings, each of the openings corresponding to a respective vent, and a double protrusion seal extending around a periphery of each of the openings and towards the battery cells, wherein the double protrusion seal of the insulating member comprises a first protrusion and a second protrusion configured to be movable with respect to the first protrusion, wherein both the first and second protrusions extend toward the battery cells;

a pressurizing member directly contacting the insulating member, the pressurizing member having a plurality of openings and a fixing protrusion extending away from the battery cells; and

a cover entirely covering the insulating member and the pressurizing member, the cover having a rib structure on and contacting the pressurizing member and a fixing groove accommodating the fixing protrusion.

2. The battery module of claim 1 , wherein the double protrusion seal extends around a periphery of the vent of at least one of the battery cells.

3. The battery module of claim 1 , wherein the pressurizing member comprises a first pressurizing member and a second pressurizing member stepped from the first pressurizing member.

4. The battery module of claim 1 , wherein the rib structure comprises a pair of first ribs having a first length and a pair of second ribs having a second length different from the first length.

5. The battery module of claim 4 , wherein the pair of first ribs contacts the first pressurizing member and wherein the pair of second ribs contacts the second pressurizing member.

6. The battery module of claim 1 , wherein each of the openings on the pressurizing member is generally aligned to a corresponding one of the openings on the insulation member.

7. The battery module of claim 1 , wherein the pressurizing member comprises a pressurizing protrusion protruding towards the battery cells.

8. The battery module of claim 7 , wherein the pressurizing protrusion is generally aligned with the protrusion seal on the insulating member.

9. The battery module of claim 1 , wherein the cover defines a discharge channel through which gas exiting the vent can flow.

10. The battery module of claim 1 , wherein the double protrusion seal comprises a flexible material.

11. The battery module of claim 1 , wherein the protrusion seal is integral as a single body with the insulating member.