Battery module and method of manufacturing the same

1. A battery module comprising:

a case providing an internal space;

a plurality of battery cells disposed in the internal space of the case; and

at least one cooling unit interposed between the plurality of battery cells to be in surface contact with the plurality of battery cells and dissipating heat generated by the plurality of battery cells,

wherein the case comprises:

a main frame having two open sides; and

side covers coupled to the two open sides of the main frame,

wherein the main frame includes a joining protrusion, and each of the side covers includes a joining groove into which the joining protrusion is inserted,

the joining protrusion is formed to protrude further than the depth of the joining groove, and

the main frame is adhered to the joining groove by melting the end of the joining protrusion,

wherein the main frame comprises two buffer plates positioned within the main frame, and the two buffer plates are spaced apart from each other by a predetermined distance,

wherein each of the two buffer plates comprises a partially bent protrusion, and

wherein the partially bent protrusion of a first buffer plate of the two buffer plates contacts the partially bent protrusion of a second buffer plate of the two buffer plates to provide a buffer space between the plurality of battery cells to allow for expansion of the plurality of battery cells.

2. The battery module of claim 1 , wherein the at least one cooling unit comprises:

a cooling plate disposed in such a manner that two surfaces of the cooling plate are in surface contact with the plurality of battery cells; and

a heat dissipating member coupled to the cooling plate and exposed outwardly of the main frame.

3. The battery module of claim 1 , further comprising at least one cell guide disposed to correspond to contours of the plurality of battery cells.

4. The battery module of claim 3 , wherein the at least one cell guide has a shape formed by bending a central portion of a linear member in such a manner that two ends of the linear member are perpendicular to each other.

5. The battery module of claim 3 , wherein the at least one cell guide is disposed on the two buffer plates or on a cooling plate disposed in the at least one cooling unit.

6. The battery module of claim 1 , wherein the main frame and the side covers are formed of a resin material, and are bonded to each other by laser welding.

7. The battery module of claim 1 , wherein the case further comprises at least one sealing cover coupled to a coupling portion between the main frame and the side covers to seal the internal space.

8. The battery module of claim 7 , wherein a portion of the at least one sealing cover is formed of a material having elasticity.

9. The battery module of claim 7 , wherein the at least one sealing cover comprises a gas outlet to allow a gas from the plurality of battery cells to be discharged externally.

10. The battery module of claim 1 , wherein each of the side covers comprises:

a side plate disposed to be in surface contact with the plurality of battery cells; and

a side frame disposed along a periphery of the side plate and bonded to the main frame.

11. The battery module of claim 10 , wherein the side plate is formed of a metal, and comprises a protrusion protruding inwardly.

12. The battery module of claim 2 , further comprising an elastic member interposed between the heat dissipating member and the main frame.