Busbar

1. A busbar comprising:

a plate-shaped body section configured to connect adjacent electrode terminals of a plurality of unit cells; and

a wire connection section integrally provided on and extended from the body section, and configured to connect an end portion of a wire,

wherein the body section comprises a first plate section, a second plate section, and at least one folding-back section connecting the first plate section and the second plate section;

wherein the first plate section and the second plate section are stacked mutually by folding-back the at least one folding-back section;

wherein the first plate section has an outer shape that is positioned to a busbar accommodation section of a wire routing member made of insulation resin;

wherein a maximum width dimension of the second plate section in a direction parallel to the at least one folding-back section is smaller than that of the first plate section in the direction parallel to the at least one folding-back section;

wherein the first plate section has:

a long-side edge section which serves a longer side of the first plate section, which faces the at least one folding-back section, and which extends in a direction parallel to an extending direction of the at least one folding-back section; and

a pair of short-side edge sections which serve short sides of the first plate section and which extend from both ends of the long-side edge section in a direction substantially perpendicular to an extending direction of the long-side edge section;

wherein two corner sections, each having substantially right angle, are formed by the long-side edge section and the short-side edge sections of the first plate section, respectively,

wherein the second plate section has:

a long-side edge section which serves a longer side of the second plate section, which faces the at least one folding-back section, and which extends in a direction parallel to the extending direction of the at least one folding-back section; and

a pair of short-side edge sections which serve short sides of the second plate section and which extend from both ends of the long-side edge section in a direction substantially perpendicular to an extending direction of the long-side edge section:

wherein two corner sections, each having substantially right angle, are formed by the long-side edge section and the short-side edge sections of the second plate section, respectively,

wherein when the second plate section is folded and stacked to the first plate section by the at least one folding-back section, one of the pair of short-side edge sections of the second plate section is stacked on one of the pair of short-side edge sections of the first plate section; and

wherein a deviation amount between the one of the pair of short-side edge sections of the second plate section and the one of the pair of short-side edge sections of the first plate section at a vicinity of corresponding corner sections of the first plate section and the second plate section in the extending direction of the at least one folding back section is defined as δ, a dimension of the long-side edge section of the first plate section is defined as L 1 , a dimension of the long-side edge section of the second plate section is defined as L 2 , and a following formula is satisfied:

L 2= L 1−2×δ.

2. The busbar according to claim 1 , wherein a difference between the maximum width dimension of the first plate section and the maximum width dimension of the second plate section in the direction parallel to the at least one folding-back section is set to a dimension capable of allowing a bending deviation amount of the second plate section with respect to the first plate section.

3. The busbar according to claim 1 , wherein a through hole for connection to the electrode terminal is formed in the body section;

wherein a first connection hole of the first plate section and a second connection hole of the second plate section configures the through hole; and

wherein an opening diameter of the second connection hole of the second plate section is larger than that of the first connection hole of the first plate section.

4. The busbar according to claim 1 , wherein the wire connection section is integrally provided on the first plate section of the body section.

5. The busbar according to claim 1 , wherein a width dimension of a side edge section of the second plate section along a direction substantially parallel to a folding-back axis of the at least one folding-back section is smaller than that of the first plate section along the direction substantially parallel to the folding-back axis of the at least one folding-back section.

6. The busbar according to claim 1 , wherein the at least one folding-back section is two folding-back sections which are separated with an air gap.