Bipolar secondary battery, battery assembly formed by connecting said batteries and vehicle mounting same
Embodiments of a battery taught herein are directed to preventing a displacement between bipolar battery stacks or between a bipolar battery stack and an electrode tab. A bonding portion is formed at a part of a contact surface where a collector positioned at both ends in a stacking direction of a bipolar battery stack is bonded to the electrode tabs. The electrode tab and the collector are fixed by such a bonding portion. Further, the bonding portion is formed at a part of a contact surface where adjacent bipolar battery stacks are bonded to each other. Bipolar batteries positioned at upper and lower portions in the stacking direction are fixed by such a bonding portion.
1. A bipolar secondary battery, comprising:
at least one bipolar battery stack, each including at least one electrolyte layer and a plurality of bipolar electrodes alternately stacked with the at least one electrolyte layer, each bipolar electrode comprising a cathode formed at a first side of a collector and an anode formed at an opposite side of the collector, and further including an end collector at each end of the bipolar battery stack having a first surface stacked on outermost bipolar electrode at a respective end of the bipolar battery stack and a contact surface facing opposite the bipolar battery stack; and
an electrode tab disposed at opposing ends of the bipolar battery stack in a stacking direction of the bipolar battery stack, each electrode tab having a contact surface and an opposing surface;
wherein the contact surface of each electrode tab is fixedly bonded to the contact surface of a respective end collector of the bipolar battery stack at a bonding portion such that the bipolar battery stack is disposed between electrode tabs in the stacking direction with the opposing surface of each electrode tab forming an outermost layer of the bipolar battery stack.
2. The bipolar secondary battery of claim 1 , wherein the at least one bipolar battery stack comprises a plurality of bipolar battery stacks layered in the stacking direction between the respective electrode tabs such that the contact surface of the end collector of a bipolar battery stack contacts the contact surface of the end collector of an adjacent bipolar battery stack; and wherein the end collectors of adjacent bipolar battery stacks are fixedly bonded to each other at a bonding portion disposed between the contact surfaces of the end collectors of the adjacent bipolar battery stacks.
3. The bipolar secondary battery of claim 1 , wherein the bonding portion is configured such that a resulting centroid axis is aligned with a centroid axis of the bipolar battery stack.
4. The bipolar secondary battery of claim 3 , wherein the bonding portion includes a two-dimensional array of contact points.
5. The bipolar secondary battery of claim 1 , wherein the bonding portion has a dot shape at two or more points.
6. The bipolar secondary battery of claim 5 , wherein the dot shape includes a two-dimensional array of contact points.
7. The bipolar secondary battery of claim 5 , wherein spacing between adjacent contact points of the two-dimensional array of contact points is about equal.
8. The bipolar secondary battery of claim 1 , wherein the bonding portion includes a conductive adhesive.
9. The bipolar secondary battery of claim 1 , wherein the electrolyte is a solid electrolyte.
10. The bipolar secondary battery of claim 1 , wherein an active material of the cathode comprises a lithium-transition metal composite oxide, and wherein an active material of the anode comprises a lithium-transition metal composite oxide or carbon.
11. A battery assembly formed by electrically connecting a plurality of the bipolar secondary batteries of claim 1 .
12. A vehicle comprising the bipolar secondary battery of claim 1 mounted therein to provide a power source for vehicle movement.
13. The bipolar secondary battery of claim 2 , wherein the bonding portion includes a conductive adhesive.
14. The bipolar secondary battery of claim 13 , wherein the bonding portion includes a two-dimensional array of dots of the conductive adhesive.
15. The bipolar secondary battery of claim 14 , wherein the two-dimensional array of dots forms a centroid axis aligned with a centroid axis of the bipolar battery stack.