Battery and method for manufacturing same

1. A battery comprising:

an electrode stacked body that includes a plurality of electrodes and a plurality of separators, wherein each of the plurality of separators is disposed between an adjacent two of the plurality of electrodes such that the plurality of electrodes and the plurality of separators are alternately stacked relative to one another; and

a film-made cover member that, by joining mutually overlapped peripheral portions of one or more films, constitutes a package for hermetically receiving therein the electrode stacked body,

wherein the plurality of separators includes first separators and second separators that are flat in shape,

wherein the first separators are larger in size than the second separators,

wherein disposed between an adjacent two of the first separators are at least two of the plurality of electrodes and at least one of the second separators, and

wherein the first separators project outward from a side of the electrode stacked body and are joined to the one or more films of the film-made cover member at a first position different from a second position at which the peripheral portions of the mutually overlapped peripheral portions of the one or more films of the film-made cover member are joined, the first position being within an interior of the film-made cover member.

2. A battery as claimed in claim 1 , in which the first separators and the second separators are alternately put on one another in a direction in which the plurality of separators are stacked.

3. A battery as claimed in claim 1 , in which the peripheral portions of the one or more films of the film-made cover member are heat joined to each other and the first separators are bonded to the one or more films of the film-made cover member through an ultrasonic welding method.

4. A battery as claimed in claim 1 , in which adjacent two of the plurality of separators are at least partially joined on at least one side and one of paired electrodes is put between the two separators that are joined.

5. A battery unit including a battery as defined by claim 1 , comprising:

a plurality of the batteries that are stacked; and

a housing that houses therein the batteries while pressing the batteries in a direction in which the batteries are stacked.

6. A method of producing a battery comprising:

enclosing an electrode stacked body with a film-made cover member, the electrode stacked body comprising a plurality of separators, which include first separators and second separators that are flat in shape, the first separators being larger in size than the second separators, and a plurality of electrodes, wherein each of the plurality of separators is disposed between an adjacent two of the plurality of electrodes such that the plurality of electrodes and the plurality of separators are alternately stacked relative to one another, and wherein disposed between an adjacent two of the first separators are at least two of the plurality of electrodes and at least one of the second separators;

producing a package for hermetically receiving therein the electrode stacked body by joining peripheral portions of one or more films of the film-made cover member that covers the electrode stacked body to one another; and

after the step of joining the peripheral portions of the one or more films of the film-made cover member to one another, joining the first separators to the one or more films of the film-made cover member at a side of the electrode stacked body at a first position different from a second position at which the peripheral portions of the one or more films of the film-made cover member are joined, the first position being within an interior of the film-made cover member.

7. A method of producing a battery as claimed in claim 6 , in which the step of producing the package for hermetically receiving therein the electrode stacked body includes a step of heat joining the peripheral portions of the one or more films of the film-made cover member, and the step of joining the first separators to the one or more films of the film-made cover member includes a step of joining the first separators to the one or more films of the film-made cover member through ultrasonic welding.

8. A battery as claimed in claim 1 , in which a space is provided between the first position where the first separators are joined to the one or more films of the film-made cover member and the second position where the peripheral portions of the one or more films of the film-made cover member are joined to each other.

9. A battery as claimed in claim 8 , in which each of the plurality of electrodes is sandwiched between adjacent two of the separators, the first separators are arranged equally spaced in a lamination direction of the electrode stacked body and peripheral portions of outermost two of the first separators are joined to each other.

10. A battery as claimed in claim 1 , wherein the second separators are not joined to the one or more films of the film-made cover member.

11. A battery as claimed in claim 1 , wherein the plurality of electrodes and the plurality of separators are alternately stacked relative to one another such that each of an adjacent two of the plurality of separators includes at least one of the plurality of electrodes disposed therebetween.

12. A method of producing a battery as claimed in claim 6 , wherein the plurality of electrodes and the plurality of separators are alternately stacked relative to one another such that each of an adjacent two of the plurality of separators includes at least one of the plurality of electrodes disposed therebetween.