Battery pack
A battery pack includes battery cell having a discharge valve opened when an internal pressure exceeds a set pressure, and case housing battery cell. Case has opening, and opening is blocked by porous plate made of resin. Porous plate has a plurality of through-holes, an expansion gap of a discharge gas is formed by stacking a plurality of the porous plates, through-holes provided in each of porous plates are arranged at non-facing positions not facing through-holes provided in adjacent another porous plate, and the discharge gas of the discharge valve passes through through-holes provided in porous plates and the expansion gap and is discharged to an outside of the case.
1. A battery pack comprising:
a battery cell having a discharge valve opened when an internal pressure of the battery cell exceeds a set pressure; and
a case housing the battery cell,
wherein
the case includes an opening,
the opening is blocked by a porous plate made of resin,
the porous plate has a plurality of through-holes,
an expansion gap of a discharge gas is defined by stacking a plurality of the porous plates each being the porous plate,
the plurality of through-holes provided in each of the porous plates are arranged at non-facing positions not facing the plurality of through-holes provided in adjacent another porous plate, and
the discharge gas of the discharge valve passes through the plurality of through-holes provided in the porous plates and the expansion gap and is discharged to an outside of the case.
2. The battery pack according to claim 1 , wherein
each of the porous plates stacked on top of each other includes a rectangular shape, and
the porous plates are stacked on inside out with a diagonal line of the rectangular shape as a symmetric axis, and the through-holes of the porous plates stacked are arranged at non-facing positions.
3. The battery pack according to claim 2 , wherein each of the porous plates has a square shape.
4. The battery pack according to claim 1 , wherein the through-holes of the porous plates stacked on an inner side of the case are larger than the through-holes of the porous plates stacked on an outer side of the case.
5. The battery pack according to claim 1 , wherein each of the porous plate is integrally molded with protrusions, and the expansion gap is defined in a state in which the porous plates are stacked.
6. The battery pack according to claim 1 , wherein an inner diameter of each of the through-holes of each of the porous plates is equal to or more than 0.5 mm and is equal to or less than 3 mm.
7. The battery pack according to claim 1 , wherein
the case is a rectangular cuboid coupling with peripheral walls around a surface plate including a square shape,
the battery cell is disposed in parallel with the surface plate, and is housed in a state in which a valve side end surface on which the discharge valve is provided faces an inside of a peripheral wall among the peripheral walls, and
the porous plates are provided on the surface plate.
8. The battery pack according to claim 1 , wherein in each of the porous plates, the through-holes are provided at intersections of a checkerboard lattice.
9. The battery pack according to claim 1 , wherein a label peeled off or melted by the discharge gas discharged from the discharge valve is attached to a surface of the porous plate in the case.
10. The battery pack according to claim 1 , wherein the battery cell is a non-aqueous electrolyte secondary battery.
11. The battery pack according to claim 10 , wherein the battery cell is a lithium-ion battery.