A battery pack includes a plurality of battery modules including at least a first group of the battery modules and a second group of the battery modules, a first coolant flow pathway through the battery modules of the first group and the second group, a second coolant flow pathway along an exterior of the battery modules of the first group, and a converging coolant flow pathway connected with the first coolant flow pathway, the converging coolant flow pathway being disposed downstream of the first group of the battery modules, the converging coolant flow pathway joining the second coolant flow pathway with the first coolant flow pathway.
1. A battery pack, comprising:
a plurality of battery modules including at least a first group of the battery modules and a second group of the battery modules;
a first coolant flow pathway through the battery modules of the first group and through the battery modules of the second group, wherein the first coolant flow pathway goes through the battery modules of the first group and then goes through the battery modules of the second group;
a second coolant flow pathway along an exterior of the battery modules of the first group; and
a converging coolant flow pathway connected with the first coolant flow pathway, the converging coolant flow pathway being disposed downstream of the first group of the battery modules, the converging coolant flow pathway joining the second coolant flow pathway with the first coolant flow pathway upstream of the second group of the battery modules.
2. The battery pack as claimed in claim 1 , further including a housing surrounding the plurality of battery modules, the housing including an inlet and an outlet for a coolant medium, wherein the battery modules are arranged in the housing such that the first group of the battery modules is closest to the inlet and the second group of the battery modules is closest to the outlet.
3. The battery pack as claimed in claim 2 , wherein the inlet includes a main inlet connected to the first coolant flow pathway and a by-pass inlet connected to the second coolant flow pathway.
4. The battery pack as claimed in claim 2 , wherein the battery modules are arranged in a first direction between the inlet and the outlet of the housing.
5. The battery pack as claimed in claim 4 , wherein the battery modules each include a plurality of battery cells that are stacked and spaced apart in a second direction, perpendicular to and crosswise to the first direction, and end plates that are disposed at opposite ends of the battery cells in the second direction.
6. The battery pack as claimed in claim 5 , wherein the second coolant flow pathway is located between the end plates of the battery modules of the first group and an interior surface of the housing.
7. The battery pack as claimed in claim 6 , wherein the plurality of battery modules are spaced apart from each other in the first direction.
8. The battery pack as claimed in claim 7 , wherein one or more sealing members are provided between battery modules of the first group to seal the first coolant flow pathway and the second coolant flow pathway from each other and between battery modules of the second group to seal the first coolant flow pathway from an exterior of the battery modules of the second group.
9. The battery pack as claimed in claim 8 , wherein the converging coolant flow pathway includes one or more guide members between a battery module of the second group that is closest to the first group of the battery modules and the interior surface of the housing to guide the converging coolant flow pathway to join the second coolant flow pathway with the first coolant flow pathway.
10. The battery pack as claimed in claim 8 , wherein:
the battery modules of the first and second groups are spaced apart from each other in the first direction by one predetermined distance,
the first group of the battery modules is spaced apart from the second group of the battery modules in the first direction by another predetermined distance, and
the other predetermined distance is greater than the one predetermined distance.
11. The battery pack as claimed in claim 7 , wherein:
the plurality of battery modules further includes a third group of the battery modules between the first group and the second group and arranged with the first group and the second group,
the first coolant flow pathway additionally passes through the battery modules of the third group,
the second coolant flow pathway additionally extends between the end plates of the battery modules of the third group and the interior surface of the housing, and
the converging coolant flow pathway includes:
a first converging coolant flow pathway joining the second coolant flow pathway with the first coolant flow pathway between the first group of the battery modules and the third group of the battery modules, and
a second converging coolant flow pathway joining the second coolant flow pathway with the first coolant flow pathway between the third group of the battery modules and the second group of the battery modules.
12. The battery pack as claimed in claim 11 , wherein:
the battery modules of the first, second and third groups are spaced apart from each other in the first direction by one predetermined distance;
the groups of battery modules are spaced apart from each other in the first direction by other predetermined distances; and
the other distances are greater than the one predetermined distance.
13. The battery pack as claimed in claim 11 , wherein one or more sealing members are provided between the battery modules of the first group and between the battery modules of the third group to seal the first coolant flow pathway from the second coolant flow pathway, and between the battery modules of the second group to seal the first coolant flow pathway from an exterior of the battery modules of the second group.
14. The battery pack as claimed in claim 13 , wherein the converging coolant flow pathway includes a step part between the first group of the battery modules and the third group of the battery modules, such that a distance between the end plates of the battery modules of the third group and the interior surface of the housing is less than a distance between end plates of the battery modules of the first group and the interior surface of the housing.
15. The battery pack as claimed in claim 14 , wherein the step part guides the first converging coolant flow pathway to join the second coolant flow pathway with the first coolant flow pathway.
16. The battery pack as claimed in claim 14 , wherein the converging coolant flow pathway further includes one or more guide members between a battery module of the second group that is closest to the third group of the battery modules and the interior surface of the housing to guide the second converging coolant flow pathway to join the second coolant flow pathway with the first coolant flow pathway.
17. The battery pack as claimed in claim 13 , wherein the converging coolant flow pathway further includes:
one or more first guide members that partially restrict the second coolant flow pathway between the end plates of the battery modules of the third group and the interior surface of the housing to guide the first converging coolant flow pathway to join the second coolant flow pathway with the first coolant flow pathway, and
one or more second guide members between battery modules of the second group that is closest to the first group of the battery modules and the interior surface of the housing to guide the second converging coolant flow pathway to join the second coolant flow pathway with the first coolant flow pathway.