All-solid-state battery stack

1. An all-solid-state battery stack comprising:

a plurality of monopolar battery units, each adjacent monopolar battery unit stacked together via insulator layers, wherein:

the monopolar battery units each have a first current collector layer, a first active material layer, a solid electrolyte layer, a second active material layer, a second current collector layer, a second active material layer, a solid electrolyte layer, a first active material layer and a first current collector layer, stacked in that order, and

the plurality of monopolar battery units are connected together in series.

2. The all-solid-state battery stack according to claim 1 , wherein for every two monopolar battery units connected in series, the pair of first current collector layers of one monopolar battery unit and the second current collector layer of the other monopolar battery unit are electrically connected.

3. The all-solid-state battery stack according to claim 1 , wherein:

a first collector tab is connected to the pair of first current collector layers of the monopolar battery unit at one end in the stacking direction of the all-solid-state battery stack, and

a second collector tab is connected to the second current collector layer of the monopolar battery unit at the other end in the stacking direction.

4. The all-solid-state battery stack according to claim 3 , which is housed inside an exterior body with the first collector tab and the second collector tab extending out of the exterior body.

5. The all-solid-state battery stack according to claim 1 , wherein:

the first current collector layer is a positive electrode collector layer, the first active material layer is a positive electrode active material layer, the second active material layer is a negative electrode active material layer and the second current collector layer is a negative electrode collector layer.

6. The all-solid-state battery stack according to claim 1 , wherein the insulator layer is an insulating polymer sheet.

7. The all-solid-state battery stack according to claim 1 , wherein the insulator layer contains insulating particles.

8. The all-solid-state battery stack according to claim 7 , wherein the insulating particles are alumina particles.

9. The all-solid-state battery stack according to claim 1 , wherein either or both of the two first current collector layers forming the monopolar battery unit are bound with the insulator layer.

10. The all-solid-state battery stack according to claim 1 , wherein one of the two first current collector layers forming the monopolar battery unit is bound with the insulator layer, composing an insulator layer-comprising monopolar battery unit, and

a plurality of insulator layer-comprising monopolar battery units are stacked together in such a manner that, for every two adjacent insulator layer-comprising monopolar battery units, the insulator layer of one insulator layer-comprising monopolar battery unit and the first current collector layer of the other insulator layer-comprising monopolar battery unit are in contact.

11. The all-solid-state battery stack according to claim 1 , wherein:

the two first current collector layers forming the monopolar battery unit are each bound with the insulator layer, composing an insulator layer-comprising monopolar battery unit, and

a plurality of insulator layer-comprising monopolar battery units are stacked together in such a manner that the insulator layers of every two adjacent insulator layer-comprising monopolar battery units are in contact.

12. The all-solid-state battery stack according to claim 1 , wherein either or both of the two first current collector layers forming the monopolar battery unit are disposed on the inner side of the outer edges of the insulator layer.

13. The all-solid-state battery stack according to claim 1 , wherein:

for every two monopolar battery units connected in series, the first current collector layers and the second current collector layer each have a body portion and a protruding section, and

the protruding sections of the pair of first current collector layers of one monopolar battery unit are electrically connected to the protruding section of the second current collector layer of the other monopolar battery unit.

14. The all-solid-state battery stack according to claim 13 , wherein:

(A) for each monopolar battery unit,

the entirety of one of the first current collector layers including the protruding section is disposed on the inner side of the outer edges of the adjacent insulator layer,

the portion of the other first current collector layer other than the protruding section is disposed on the inner side of the outer edges of the adjacent insulator layer while the protruding section protrudes from the outer edges of the adjacent insulator layer,

the protruding section of one first current collector layer and the protruding section of the other first current collector layer are disposed at positions that overlap in the stacking direction of the monopolar battery unit, and

the protruding sections of the pair of first current collector layers and the protruding section of the second current collector layer are disposed at positions that do not overlap in the stacking direction of the monopolar battery unit, and

(B) for every two monopolar battery units connected in series,

the two monopolar battery units are adjacent across an insulator layer, and

the protruding sections of the pair of first current collector layers of one monopolar battery unit and the protruding section of the second current collector layer of the other monopolar battery unit are disposed at positions that overlap in the stacking direction of the monopolar battery unit and are electrically connected.