Fluid-cooled battery system

1. A fluid-cooled battery system comprising at

least one battery module which includes:

a plurality of rows of battery cells, each of said battery cells having a cell body extending in an upright direction, said battery cells of each row being staggered with said battery cells of an adjacent row;

a cooling fluid;

an outer casing defining therein an accommodation space for accommodation of said battery cells, and having a first opening and a second opening which are configured to permit said cooling fluid to flow through said accommodation space from one of said first and second openings to the other one of said first and second openings so as to allow said battery cells to be cooled by said cooling fluid; and

at least one cell fixture which is fitted inside said accommodation space, and which is formed with a plurality of rows of retaining holes, said retaining holes of each row being staggered with said retaining holes of an adjacent row, and being configured to retain said cell bodies of a respective row of said battery cells so as to permit said battery cells to be held in said accommodation space by said cell fixture, to thereby keep said battery cells in stable position against undesired vibration,

wherein each of said battery cells has a first terminal and a second terminal which are opposite to each other in the upright direction to be disposed at two opposite sides of said cell fixture;

wherein said battery module further includes a first electrode plate which is electrically connected to said first terminals of said battery cells, and a second electrode plate which is electrically connected to said second terminals of said battery cells;

wherein said battery cells, said first and second electrode plates, and electrical connections among said battery cells and said first and second electrode plates are completely submerged in said cooling fluid;

wherein said outer casing includes a surrounding wall extending in the upright direction to terminate at a first surrounding edge and a second surrounding edge, which define said first and second openings, respectively;

wherein each of said first and second electrode plates is fitted in a respective one of said first and second openings, and has a plurality of passing holes for passage of said cooling fluid;

wherein the fluid-cooled battery system comprises a plurality of said battery modules; and

wherein said outer casing further includes a female edge extension and a male edge extension which respectively extend from said first and second surrounding edges, and which are configured to mate with each other such that when said male edge extension of one of said battery modules is brought into mating engagement with said female edge extension of an adjacent one of said battery modules, said first electrode plate of said one of said battery modules is brought into electrical contact with said second electrode plate of the adjacent one of said battery modules.

2. The fluid-cooled battery system according to claim 1 , wherein said retaining holes of each odd row are staggered with said retaining holes of an adjacent even row to leave a pair of outboard regions disposed outboard of said retaining holes of the adjacent even row, two through holes being formed respectively in said outboard regions for passage of said cooling fluid.

3. The fluid-cooled battery system according to claim 2 , wherein said cell fixture has a plurality of inner peripheral surfaces which define said retaining holes, respectively, each of said inner peripheral surfaces being formed with at least one groove which extends in the upright direction to permit passage of said cooling fluid.

4. The fluid-cooled battery system according to claim 3 , wherein each of said inner peripheral surfaces is formed with two of said grooves which are diametrically opposite to each other.

5. The fluid-cooled battery system according to claim 1 , wherein said battery module includes two of said cell fixtures which are displaced from each other in the upright direction.

6. The fluid-cooled battery system according to claim 1 , wherein said first electrode plate includes

a plate body formed with a plurality of through bores in positions corresponding to said first terminals of said battery cells,

a plurality of contact pads disposed respectively in said through bores to be in electrically contact with said first terminals of said battery cells, respectively, and

a plurality of fusible regions located respectively in said through bores, and each of said fusible regions including a plurality of fusible ribs which are angularly displaced from each other and which extend radially from said respective contact pad to said plate body for electrically connection between said plate body and said respective contact pad.

7. The fluid-cooled battery system according to claim 1 , wherein said passing holes are in positions corresponding to said grooves of said cell fixture.

8. The fluid-cooled battery system according to claim 1 , wherein said cooling fluid is an inert dielectric fluid which provides a fire suppression capability.

9. The fluid-cooled battery system according to claim 8 , wherein said cooling fluid is selected from the group consisting of mineral oil, silicone oil, ester-based oil, engineered fluid, or combinations thereof.