Power storage
A power storage includes a stack made of stacked power storage cells and a casing in which the stack is accommodated. The casing includes a pair of wall portions provided such that the stack lies therebetween in a direction of stack. Each of the pair of wall portions includes a central portion located in a center in a plane direction orthogonal to the direction of stack and an outer peripheral portion located around the central portion. Each of the pair of wall portions is in such a recessed shape that the central portion is closer to the stack than the outer peripheral portion. The stack is sandwiched between the central portions included in the pair of wall portions.
1 . A power storage comprising:
a stack made of stacked power storage cells; and
a casing in which the stack is accommodated, wherein
the casing includes an upper case and a lower case, with respect to a stacked direction of the stack, wherein the upper case and the lower case are fixed to each other,
the upper case includes an upper wall portion and an upper peripheral wall portion that extends downward from around a periphery of the upper wall portion, so that the upper case has an open box shape,
the upper wall portion includes a central portion located in a center in a plane direction orthogonal to the stacking direction and an outer peripheral portion located around the central portion so as to be between the central portion and the periphery of the upper wall portion, wherein the upper wall portion has a recessed shape such that the central portion is closer to the stack than the outer peripheral portion,
the lower case includes a lower wall portion and a lower peripheral wall portion that extends upward from around a periphery of the lower wall portion, so that the lower case has an open box shape,
the lower wall portion includes a central portion located in a center in a plane direction orthogonal to the stacking direction and an outer peripheral portion located around the central portion so as to be between the central portion and the periphery of the lower wall portion, wherein the lower wall portion has a recessed shape such that the central portion is closer to the stack than the outer peripheral portion, and
the stack is sandwiched between the central portion of the upper wall portion and the central portion of the lower wall portion, and
an outer surface of a tip end of the lower peripheral wall portion overlaps with an inner surface of a tip end of the upper peripheral wall portion, as viewed from a side view of the case, so that the outer surface of the tip end of the lower peripheral wall portion presses into the inner surface of the tip end of the upper peripheral wall portion and an upper surface of the tip end of the lower peripheral wall portion, which is further upward than the outer surface, is not in contact with the upper peripheral wall portion, and
a lower portion of the upper peripheral wall portion is deformed outward from the tip end of the lower peripheral wall portion in a facing direction in which the tip end of the upper peripheral wall portion and the tip end of the lower peripheral wall portion face each other.
2 . The power storage according to claim 1 , wherein
each of the power storage cells includes an electrode assembly, an exterior film with which the electrode assembly is sealed, an electrolyte solution accommodated inside of the exterior film, and a current collection plate connected to the electrode assembly and provided to protrude from the exterior film, and
the power storage further comprises an insulating cover portion that covers a part of the current collection plate that protrudes from the exterior film.
3 . The power storage according to claim 2 , wherein
the cover portion includes an adhesive that bonds the exterior film and the current collection plate with each other and a filling member with which the casing is partially filled, and
the filling member is provided to cover the adhesive and the part of the current collection plate that protrudes from the adhesive and the exterior film.
4 . The power storage according to claim 2 , wherein
the cover portion includes an adhesive that bonds the exterior film and the current collection plate with each other and a filling member partially filling the casing,
the filling member covers a part of the current collection plate that protrudes from the adhesive and the exterior film, and
the adhesive covers a part of the current collection plate which the filling member is absent therefrom.
5 . The power storage according to claim 2 , further comprising:
a bus bar, wherein
the cover portion includes an adhesive that bonds the exterior film and the current collection plate with each other and a filling member with which the casing is partially filled,
each current collection plate includes a positive electrode current collection plate and a negative electrode current collection plate,
the positive electrode current collection plate and the negative electrode current collection plate are connected to each other through the bus bar, and
the bus bar is covered by the filling member.
6 . The power storage according to claim 2 , wherein
the cover portion includes an adhesive that bonds the exterior film and the current collection plate with each other and a filling member partially filling the casing, and
the adhesive covers all of the current collection plate which is not covered by the filling member.
7 . The power storage according to claim 2 , wherein
the cover portion includes an adhesive that bonds the exterior film and the current collection plate with each other and a filling member partially filling the casing, and
the filling member is in contact with a side walls of the casing.
8 . The power storage according to claim 2 , wherein the cover portion includes:
an adhesive that bonds the exterior film and the current collection plate with each other, and
a filling member with which the casing is partially filled, wherein the filling member is not in contact with the exterior film.
9 . The power storage according to claim 1 , wherein
the upper peripheral wall portion includes
a portion having an outer surface that is substantially flush with an outer surface of an upper portion of the lower peripheral wall portion,
the tip end of the upper peripheral wall portion, and
a connecting portion that connects the portion and the tip end of the upper peripheral wall portion,
the connecting portion expands outward in the facing direction as the connecting portion extends downward.
10 . The power storage according to claim 1 , further comprising a sealing member arranged between the tip end of the lower peripheral wall portion and the upper peripheral wall portion.
11 . The power storage according to claim 1 , wherein an amount of recess of the central portion of the upper wall portion as compared with the outer peripheral portion of the upper wall portion in a state before the stack is sandwiched between the upper wall portion and the lower wall portion is smaller than an amount of recess in a state after the stack is sandwiched between the upper wall portion and the lower wall portion.