A battery pack according to an aspect of the present disclosure includes a secondary battery and a battery case that houses the secondary battery. The battery case includes an exhaust section that exhausts gas exhausted from the secondary battery to outside of the battery case. The exhaust section includes at least one slit that is opened along with deformation of the exhaust section occurring in accordance with an increase in pressure in the battery case. In the exhaust section, the slits preferably reversibly operate due to the pressure in the battery case.
1 . A battery pack comprising:
a secondary battery; and
a battery case that houses the secondary battery,
wherein
the battery case includes an exhaust section through which gas discharged from the secondary battery is exhausted to outside of the battery case,
the exhaust section includes a plurality of slits and a deformable region located between the plurality of slits,
each of the plurality of slits comprises a through-opening, and
the through-opening is brought into an open state in response to discharge of the gas and is brought into a closed state having a smaller degree of opening than the open state when the discharge of the gas does not occur.
2 . The battery pack according to claim 1 , wherein the exhaust section contains an aluminum material or a stainless steel material.
3 . The battery pack according to claim 1 , wherein at least one of the plurality of slits includes a linear shape.
4 . The battery pack according to claim 1 , wherein at least one of the plurality of slits includes a bent portion.
5 . The battery pack according to claim 1 , wherein the plurality of slits overlap.
6 . The battery pack according to claim 1 , further comprising a covering member which covers the exhaust section.
7 . The battery pack according to claim 6 , wherein the covering member contains an air-permeable and waterproof material.
8 . The battery pack according to claim 1 , wherein a width of the through-opening is equal to or greater than 5 μm and equal to or less than 2 mm.
9 . The battery pack according to claim 1 , wherein a width of the through-opening is equal to or greater than 30 μm and equal to or less than 1 mm.
10 . The battery pack according to claim 1 , wherein the through-opening is brought into the open state in response to discharge of the gas as the deformable region deforms in a thickness direction of the exhaust section.
11 . The battery pack according to claim 1 , wherein deformation of the deformable region reversibly changes a shape of the deformable region while being supported at least by two opposing portions of the exhaust section, the opposing portions facing each other across the deformable region.