Capacitive communication layer for cell integrated battery management system

1. A battery module including a plurality of battery cells coupled together by a power line and a communications link, each battery cell comprising:

a cell element providing electrical power and being electrically coupled in series by the power line to a cell element in an adjacent cell, said cell element including a first side and a second side;

an electronic monitoring unit including electronic components for measuring a voltage of the cell element;

a first capacitor plate pair including a first capacitor plate and a second capacitor plate positioned at the first side of the cell element, said first capacitor plate pair being electrically coupled to the monitoring unit and being electrically isolated from the cell element; and

a second capacitor plate pair including a first capacitor plate and a second capacitor plate positioned at the second side of the cell element, said second capacitor plate pair being electrically coupled to the monitoring unit and being electrically isolated from the cell element, wherein the first capacitor plate at the second side of the cell element is capacitively coupled to the first capacitor plate at the first side of the cell element in the adjacent cell and the second capacitor plate at the second side of the cell element is capacitively coupled to the second capacitor plate at the first side of the cell element in the adjacent cell, and wherein the capacitive coupling between the capacitor plates provides DC breaking in the communications link.

2. The battery module according to claim 1 wherein all of the capacitor plates are metal foils.

3. The battery module according to claim 2 wherein the first and second capacitor plates in the first capacitor plate pair are directly electrically coupled to the electronic monitoring unit.

4. The battery module according to claim 3 wherein the first capacitor plate and the second capacitor plate in the second capacitor plate pair include extended terminals that are folded over the cell element and are electrically coupled to the electronic monitoring unit.

5. The battery module according to claim 1 wherein each battery cell further comprises a cooling fin positioned between the cell element and the second pair of capacitor plates.

6. The battery module according to claim 1 wherein the cell elements are lithium-ion pouch elements.

7. The battery module according to claim 1 wherein the electronic monitoring unit includes a universal asynchronous receiver/transmitter (UART) that provides a full-duplex communications layer where signal flow is provided in one direction on signal lines in the communications link.

8. The battery module according to claim 1 wherein the electronic monitoring unit includes a low voltage differential signal (LVDS) device that provides a half-duplex communications layer where signal flow is provided in both directions on signal lines in the communications link.

9. The battery module according to claim 1 wherein the battery module is part of a high voltage battery on a vehicle.

10. The battery module according to claim 1 wherein the communications link is electrically coupled to a battery system manager.

11. The battery module according to claim 1 wherein a distance between the first capacitor plate at the second side of the cell element and the first capacitor plate at the first side of the cell element in the adjacent cell and the distance between the second capacitor plate at the second side of the cell element and the second capacitor plate at the first side of the cell element of the adjacent cell is less than 0.1 mm.

12. A high voltage battery for a vehicle, said high voltage battery including a plurality of battery modules each including a plurality of battery cells where the battery cells in all of the modules are coupled together by a power a line and a communications link, each battery cell comprising:

a cell element providing electrical power and being electrically coupled in series by the power line to a cell element in an adjacent cell element, said cell element including a first side and a second side;

an electronic monitoring unit positioned at the first side of the cell element and including electronic components that measure a voltage of the cell element;

a cooling fin positioned at the second side of the cell element and being in contact therewith;

a first capacitor plate pair including a first capacitor plate and a second capacitor plate positioned at the first side of the cell element, said first capacitor plate being electrically coupled to the monitoring unit and being electrically isolated from the cell element; and

a second capacitor plate pair including a first capacitor plate and a second capacitor plate positioned adjacent to the cooling fin and opposite to the cell element at the second side of the cell element, said second capacitor plate pair being electrically coupled to the monitoring unit and being electrically isolated from the cooling fin, wherein the first capacitor plate at the second side of the cell element is capacitively coupled to the first capacitor plate at the first side of the cell element of the adjacent cell and the second capacitor plate at the second side of the cell element is capacitively coupled to the second capacitor plate at the first side of the cell element of the adjacent cell, and wherein the capacitive coupling between the capacitor plates provides DC breaking in the communications link.

13. The battery module according to claim 12 wherein all of the capacitor plates are metal foils.

14. The battery module according to claim 13 wherein the first and second capacitor plates in the first capacitor plate pair are directly electrically coupled to the electronic monitoring unit.

15. The battery module according to claim 14 wherein the first capacitor plate and the second capacitor plate in the second capacitor plate pair include extended terminals that are folded over the cell element and are electrically coupled to the electronic monitoring unit.

16. The battery module according to claim 12 wherein a distance between the first capacitor plate at the second side of the cell element and the first capacitor plate at the first side of the cell element in the adjacent cell and the distance between the second capacitor plate at the second side of the cell element and the second capacitor plate at the first side of the cell element of the adjacent cell is less than 0.1 mm.

17. A battery module including a plurality of battery cells coupled together by a power line and a communications link, each battery cell comprising:

a cell element providing electrical power and being electrically coupled in series along the power line to a cell element in an adjacent cell element, said cell element including a first side and a second side;

an electronic monitoring unit including electronic components for measuring a voltage of the cell element;

a first capacitor plate positioned at the first side of the cell element, said first capacitor plate being electrically coupled to the monitoring unit and being electrically isolated from the cell element; and

a second capacitor plate positioned at the second side of the cell element, said second capacitor plate being electrically coupled to the monitoring unit and being electrically isolated from the cell element, wherein the first capacitor plate at the first side of the cell element is capacitively coupled to the second capacitor plate at the second side of the cell element in the adjacent cell, and wherein the capacitive coupling between the capacitor plates provides DC breaking in of the communications link.

18. The battery module according to claim 17 wherein all of the capacitor plates are metal foils.

19. The battery module according to claim 18 wherein the first capacitor plate is directly electrically coupled to the electronic monitoring unit.

20. The battery module according to claim 19 wherein the second capacitor plate includes an extended terminal that is folded over the cell element and is electrically coupled to the electronic monitoring unit.