A battery module including a plurality of battery cells aligned in a direction; first and second end plates respectively arranged at outer sides of the plurality of battery cells; and a bottom plate supporting bottom surfaces of the battery cells and including at least a portion including a pattern structure.
1. A battery module comprising:
a plurality of battery cells aligned in a direction;
first and second end plates respectively arranged at outer sides of the plurality of battery cells;
a bottom plate supporting bottom surfaces of the battery cells and comprising at least a portion including a pattern structure, the pattern structure including at least one recessed portion on a second surface of the bottom plate opposite a first surface of the bottom plate which faces the bottom surfaces of the battery cells, and at least one opening formed through the at least one recessed portion; and
a barrier between adjacent battery cells of the plurality of battery cells, wherein the at least one opening is at a location corresponding to the barrier.
2. The battery module according to claim 1 , wherein the bottom plate comprises a plastic material.
3. The battery module according to claim 1 , wherein the pattern structure comprises a honeycomb structure.
4. The battery module according to claim 1 , wherein the pattern structure further includes a protruding portion surrounding an outer circumference of the at least one recessed portion.
5. The battery module according to claim 1 , wherein the bottom plate comprises a base portion facing the bottom surfaces of the battery cells, and at least one flange portion extending at an angle from at least one side of the base portion and facing side surfaces of the battery cells.
6. The battery module according to claim 5 ,
wherein the at least one flange portion comprises first and second flange portions respectively extending from opposite sides of the base portion, and
wherein the first and second flange portions extend between the first and second end plates and overlap at least portions of the side surfaces of the battery cells.
7. The battery module according to claim 1 , wherein the at least one recessed portion has at least one of a hexagonal shape, a triangular shape, a rectangular shape, or a circular shape.
8. The battery module according to claim 1 , wherein the pattern structure comprises a repetitive pattern structure.
9. The battery module according to claim 1 ,
wherein the bottom plate comprises a guide portion at a location corresponding to a position of a battery cell of the plurality of battery cells, and
wherein the guide portion faces the battery cell to guide the battery cell into the position.
10. The battery module according to claim 1 ,
wherein at least one of the first and second endplates has a first fastening hole at a portion that contacts an end of the bottom plate, and
wherein the bottom plate has a second fastening hole at a location corresponding to the first fastening hole.
11. The battery module according to claim 10 , further comprising fastening members in the first and second fastening holes and fastening the first and second end plates to the bottom plate.
12. The battery module according to claim 11 , wherein the fastening members comprise bolts or studs.
13. The battery module according to claim 1 , further comprising a connecting member connecting the first and second end plates to each other.
14. The battery module according to claim 13 , wherein the connecting member comprises side plates respectively supporting opposite side surfaces of the battery cells.