MULTI-CELL LITHIUM-ION BATTERIES

• US 20150155596A1
• Filed: 05/21/2013
• Published: 06/04/2015
• Est. Priority Date: 05/21/2012
• Status: Active Application

• Current Assignee: A123 Systems Incorporated
• Original Assignee: A123 Systems Incorporated
• Inventors: Gardner, William H.
• Granted Patent: US 10,128,536 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• CPC Class Codes: H01M 10/049 Processes for forming or storing electrodes in the battery container
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 50/529 Intercell connections through partitions, e.g. in a battery casing
• CPC Class Codes: H01M 50/531 Electrode connections inside a battery casing
• CPC Class Codes: H01M 50/533 characterised by the shape of the leads or tabs
• CPC Class Codes: H01M 50/534 characterised by the material of the leads or tabs
• CPC Class Codes: H01M 50/581 in response to temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

Lithium ion (Li-ion) multi-cell batteries in which the requirements for individual monitoring and controlling charging of each cell, the requirements for monitoring and controlling charge balancing and the effects of repeated charging and discharging are ameliorated are presented. In one or more embodiments, the multi-cell battery includes configuration material that substantially provides a moisture barrier.

Claims

1. A battery comprising:

a container having a number of cell cavities;

a number of electrochemical assemblies, each electrochemical assembly enfolded, one of said number of electrochemical assemblies disposed in each one of said number of cell cavities;

each one of said number of electrochemical assemblies comprising;

a positive electrode and a negative electrode; and

a separator material between the positive electrode and the negative electrode;

an electrolyte in each cell cavity from said number of cell cavities, said electrolyte comprising a lithium salt and a redox shuttle;

said electrolyte and electrodes selected to, during battery operation, provide substantially a predetermined voltage across each electrochemical assembly in said each cell cavity;

said redox shuttle being selected to substantially provide shuttle operations when voltage across each electrochemical assembly in each cell cavity reaches substantially another predetermined voltage; and

a cover disposed on said container;

said cover being permanently attached to said container so as to form a substantially hermetic seal between said cover and said container;

said cover forming a seal between said each cell cavity.

2. The battery of claim 1 wherein the redox shuttle comprises an aromatic compound having at least one aromatic ring with four or more electronegative substituents, two or more oxygen atoms bonded to said at least one aromatic ring, and no hydrogen atoms bonded to said at least one aromatic ring.

3. The battery of claim 1 further comprising a number of bar connectors securely attached to each one positive electrode and to each one negative electrode in said each one electrochemical assembly;

at least one bar connector being securely attached to said each one positive electrode and at least another one bar connector being securely attached to said each one negative electrode.

4. The battery of claim 3 wherein said each electrochemical assembly comprises a substantially spirally wound electrochemical assembly.

5. The battery of claim 4 wherein said substantially spirally wound electrochemical assembly has an inner surface and an outer surface, the inner surface defining a central space;

and wherein said central space is substantially filled with a compliant material, said compliant material having elastic behavior,

wherein said compliant material comprises a flexible and inert polymer,

wherein said flexible and inert polymer comprises polyisobutylene.

8. The battery of claim 4 wherein an outer surface of said substantially spirally wound electrochemical assembly is inclined with respect to a center axis of said substantially spirally wound electrochemical assembly;

inclination constituting a taper, said taper being selected to be substantially equal to a taper of walls of each cell cavity from the number of cell cavities.

9. The battery of claim 3 wherein at least some of the of the number of electrochemical assemblies are connected in series;

and wherein the battery comprises at least one bimetallic joint connector connecting the positive electrode in one electrochemical assembly to the negative electrode in another one of said number of electrochemical assemblies in order to connect said one electrochemical assembly in series with said another one of said number of electrochemical assemblies;

wherein one section of said at least one bimetallic joint connector comprises a metal compatible with the positive electrode and another section of said bimetallic joint connector comprises another metal compatible with the negative electrode;

said one section being electrically operatively connected to said another section,

wherein externally exposed surfaces of said at least one bimetallic joint connector are substantially covered with an electrolyte resistant material,

wherein said electrolyte resistant material comprises an electrolyte resistant polymer,

wherein said electrolyte resistant polymer comprises polypropylene.

13. The battery of claim 1 wherein said container comprises a layer of conductive material substantially providing a barrier to moisture and vapors.

14. The battery of claim 13 wherein said layer of conductive material is embedded within walls of said container.

15. The battery of claim 14 wherein said layer of conductive material is disposed on external surfaces of said container.

16. The battery of claim 14 wherein said layer of conductive material is disposed on internal surfaces of said container.

17. The battery of claim 13 further comprising a desiccant component disposed inside each cell cavity.

18. The battery of claim 1 wherein said cover comprises a conductive material layer disposed on an internal surface of said cover;

said conducting material layer substantially providing a moisture barrier.

19. The battery of claim 3 wherein said each electrochemical assembly comprises a substantially spirally wound electrochemical assembly;

wherein said each substantially spirally wound electrochemical assembly has a hollow center; and

wherein said hollow center is substantially filled with a compliant material, said compliant material having elastic behavior;

wherein at least some electrochemical assemblies from the number of electrochemical assemblies are connected in series; and

wherein the battery comprises at least one bimetallic joint connector connecting the positive electrode in one electrochemical assembly to the negative electrode in another electrochemical assembly in order to connect said one electrochemical assembly in series with said another electrochemical assembly;

wherein one section of said at least one bimetallic joint connector comprises a metal compatible with the positive electrode and another section of said bimetallic joint connector comprises another metal compatible with the negative electrode;

said one section being electrically operatively connected to said another section;

externally exposed surfaces of said at least one bimetallic joint connector being substantially covered with an electrolyte resistant material;

said container comprising a layer of conducting material substantially providing a barrier to moisture and vapors; and

said cover comprising a conducting material layer disposed on an internal surface of said cover;

said conducting material layer substantially providing a moisture barrier,

wherein said each electrochemical assembly is connected in series with another one of said number of electrochemical assemblies.

21. The battery of claim 19 wherein the positive electrode in said each electrochemical assembly comprises an olivine compound having a composition Li_xM′

_yM″

_a(PO₄), and a predetermined surface area, wherein M′

is at least iron, M″

is a first row transition metal selected from Ti, V, Cr, Mn, Co and Ni, x is equal to or greater than 0, and a and y are greater than 0.

22. The battery of claim 19 wherein the positive electrode in said each electrochemical assembly comprises a lithium transition metal phosphate material having a predetermined specific surface area and including only one transition metal, the lithium transition metal phosphate material, and the surface area selected to provide at least two co-existing olivine phases during cycling of the battery, wherein the two co-existing olivine phases include a lithium-rich transition metal phosphate phase and a lithium-poor transition metal phosphate phase, wherein a percentage molar volume difference between the two phases is less than about 6.4%,

wherein the predetermined specific surface area is at least about 20 m²/g.

24. The battery of claim 1 wherein the positive electrode in each electrochemical assembly comprises an olivine compound having a composition Li_xM′

_yM″

(PO₄), and a predetermined surface area, wherein M′

is at least iron, M″

is a first row transition metal selected from Ti, V, Cr, Mn, Co and Ni, x is equal to or greater than 0, and a and y are greater than 0.

25. The battery of claim 1 wherein the positive electrode in each electrochemical assembly comprises a lithium transition metal phosphate material having a predetermined specific surface area and including only one transition metal, the lithium transition metal phosphate material, and the surface area selected to provide at least two co-existing olivine phases during cycling of the battery, wherein the two co-existing olivine phases include a lithium-rich transition metal phosphate phase and a lithium-poor transition metal phosphate phase, wherein a percentage molar volume difference between the two phases is less than about 6.4%,

wherein the predetermined specific surface area is at least about 20 m²/g.

6-7. -7. (canceled)

10-12. -12. (canceled)

20. (canceled)

23. (canceled)

26. (canceled)

27. A method for obviating the need for a battery management system to balance cells in a multi-cell battery, the method comprising:

providing a number of electrochemical assemblies, each electrochemical assembly disposed in one cell cavity from a number of cell cavities;

each one electrochemical assembly from said number of electrochemical assemblies comprising a positive electrode and a negative electrode; and

a separator material between the positive electrode and the negative electrode; and

providing an electrolyte in each cell cavity from said number of cell cavities, said electrolyte containing a lithium salt and a redox shuttle;

said electrolyte and electrodes selected to, during battery operation, provide substantially a predetermined voltage across each electrochemical assembly in said each cell cavity;

said redox shuttle being selected to substantially provide shuttle operations when voltage across each electrochemical assembly in said each cell cavity reaches substantially another predetermined voltage;

cells being balanced by maintaining battery voltage at yet another predetermined voltage for a predetermined time;

said yet another predetermined voltage being related to said another predetermined voltage.

28. The method of claim 27 wherein the redox shuttle comprises an aromatic compound having at least one aromatic ring with four or more electronegative substituents, two or more oxygen atoms bonded to the aromatic ring, and no hydrogen atoms bonded to the aromatic ring.