Battery

1. A battery comprising:

a plurality of stacked unit-cell layers stacked on one another in a stacked direction, including:

a first unit-cell layer including at least:

a first unit cell;

a first frame member which holds the first unit cell therein, wherein the first frame member includes an inlet for introducing a coolant into the inside of the battery and an outlet for discharging the coolant which has passed through the inside of the battery; and

a space provided between the first unit cell and the first frame member through which the coolant passes; and

a second unit-cell layer adjacent the first unit-cell layer in the stacked direction including at least a second unit cell and a second frame member which holds the second unit cell therein in the stacked direction relative to the first unit cell, wherein the first and second unit cells are flat unit cells each having a major surface facing in the stacked direction and each comprising a power generating element and an insulating cover covering the power generating element along the respective major surface, and wherein the first unit cell is held in contact at the major surface thereof with the second unit cell in the stacked direction.

2. A battery according to claim 1 , wherein

a coolant passage is provided from the inlet to the outlet inside the battery through which the introduced coolant flows and comes into direct contact with at least the first unit cell.

3. A battery according to claim 2 , further comprising:

a heat sink provided on at least one of a top of the stacked unit-cell layers and on a bottom of the stacked unit-cell layers.

4. A battery according to claim 1 , wherein

the inlet is larger in cross-sectional area than the outlet.

5. A battery according to claim 1 , wherein

size of the inlet and/or the outlet varies between the unit-cell layers.

6. A battery according to claim 2 , wherein

the coolant passage is adapted to enable a flow of the coolant therethrough to increase its velocity as the coolant flows downstream.

7. A battery according to claim 3 , wherein

the first and second frame members comprise an outer frame portion and a plurality of cross member portions extended between the outer frame portion, and

the first and second unit cells are respectively held at a periphery thereof by the outer frame portion and/or the cross member portions.

8. A battery comprising:

unit-cell layers stacked on one another in a stacked direction, the unit-cell layers comprising:

an array of unit cells;

a frame member which holds the array of unit cells therein, wherein at least one of frame members is formed to have an inlet for introducing a coolant into the inside of the battery and an outlet for discharging the coolant which has flown through the inside of the battery, wherein spaces are provided between respective unit cells and the frame member through which the coolant passes, wherein the unit cells are flat unit cells each having a respective major surface facing in the stacked direction and respectively comprising a power generating element and an insulating cover covering the power generating element along the respective major surfaces, and wherein the unit cells in adjacent unit-cell layers are held in contact at the major surfaces thereof with each other in the stacked direction; and

a heat sink provided on at least one of on top of the stacked unit-cell layers, on a bottom of the stacked unit-cell layers, and between the stacked unit-cell layers,

wherein a coolant passage is provided from the inlet to the outlet inside the battery, through which the introduced coolant flows and comes into direct contact with at least one of the unit cells,

wherein the frame members comprise an outer frame portion and a plurality of cross member portions extended between the outer frame portion,

wherein the unit cells are held at periphery thereof by the outer frame portion and/or the cross member portions, and

wherein the inlet comprises an opening formed on the outer frame portion of the frame member on one side of the battery, the outlet comprises an opening formed on the outer frame portion of the frame member on the other side of the battery, and the coolant passage includes openings each formed on the cross member portions of the frame member.

9. A battery according to claim 8 , wherein

the coolant passage includes a groove formed on a top surface or a bottom surface of the frame member where a periphery of the unit cell contacts.

10. A battery according to claim 8 , wherein

the more downstream the openings of the coolant passage are provided, the smaller in size the openings become.

11. A method for cooling a battery which comprises unit-cell layers stacked on one another in a stacked direction, the unit-cell layers comprising an array of unit cells and a frame member for holding the array of unit cells therein, wherein the unit cells are flat unit cells each having a respective major surface facing in the stacked direction and respectively comprising a power generating element and an insulating cover covering the power generating element along the major surface, and wherein the unit cells in adjacent unit-cell layers are held in contact at respective major surfaces thereof with each other in the stacked direction, the method comprising:

providing a network of coolant flow paths comprising spaces defined between outer surfaces of the unit cells and inner surfaces of the frame members inside the battery; and

enabling a coolant to flow through the network of coolant flow paths, wherein the coolant flow increases in velocity due to variations in cross-sectional area of at least one of the coolant flow paths, thereby increasing velocity of coolant flow in the network.

12. A battery according to claim 1 , further comprising:

a network of layered sub-networks of coolant flow paths, the sub-networks being defined between one of the frame member and the unit cells of the respective unit-cell layers.

13. A battery according to claim 1 , wherein the second frame member also includes a separate inlet from that of the first frame member for introducing a coolant into the inside of the battery and a separate outlet from that of the second frame member for discharging the coolant which has flown through the inside of the battery.

14. A battery comprising:

a plurality of stacked unit-cell layers stacked on one another in a stacked direction, including:

a first unit-cell layer including at least:

a plurality of first unit cells;

a first frame member which holds the first unit cells therein, wherein the first frame member includes an inlet for introducing a coolant into the inside of the battery and an outlet for discharging the coolant which has flown through the inside of the battery; and

a space provided between the first unit cells and the first frame member through which the coolant passes; and

a second unit-cell layer adjacent the first unit-cell layer in the stacked direction including at least a plurality of second unit cells and a second frame member which holds the second unit cells therein;

wherein the first and second unit cells are flat unit cells respectively having a major surface facing in the stacked direction and respectively comprising a power generating element and an insulating cover covering the power generating element along the major surface,

wherein at least one of the first unit cells is held in contact at the major surface thereof with one of the second unit cells in the stacked direction, and

wherein the first frame member and the second frame member are of a generally rectangular configuration from the perspective of the stacked direction, and wherein the rectangular configuration is bifurcated by at least one cross member substantially parallel to two of the legs of the rectangular configuration and normal to the two other legs of the rectangular configuration and respectively provided between individual cells of the plurality of the first unit cells and the second unit cells parallel to sides of individual unit cells.

15. A battery according to claim 14 , wherein the second frame member also includes a separate inlet from that of the first frame member for introducing a coolant into the inside of the battery and a separate outlet from that of the second frame member for discharging the coolant which has passed through the inside of the battery.

16. A battery according to claim 14 , further comprising a coolant passage between the inlet and the outlet that is adapted to enable a flow of the coolant therethrough to increase its velocity as the coolant flows from the inlet to the outlet.

17. A battery according to claim 14 , wherein cross members include respective notches, wherein the battery includes a coolant passage extending between the inlet and the outlet that also extends through the notches of the cross members, wherein the sizes of the inlet, the notches, and the outlet are progressively smaller in the direction of coolant flow, and wherein the inlet, the notches and the outlet are adapted to enable flow of the coolant therethrough to increase its velocity as the coolant flows from the inlet to the outlet.

18. A battery according to claim 14 , wherein the plurality of first unit cells are held in contact, respectively, with the plurality of second unit cells in the stacked direction.

19. A battery according to claim 1 , wherein the first unit cell is held in direct abutting contact with the second unit cell in the stacked direction.

20. A battery according to claim 14 , wherein the plurality of first unit cells are held in direct abutting contact, respectively, with the plurality of second unit cells in the stacked direction.