Lithium rechargeable cell with reference electrode for state of health monitoring

• US 8,163,410 B2
• Filed: 09/15/2008
• Issued: 04/24/2012
• Est. Priority Date: 09/14/2007
• Status: Active Grant

• Current Assignee: A123 Systems Incorporated
• Original Assignee: A123 Systems Incorporated
• Inventors: Fulop, Ricardo, Chiang, Yet-Ming, Gardner, William H., Thomas-Alyea, Karen E.
• Primary Examiner(s): Menon, Krishnan S
• Application Number:
  US12/210,812
• Publication Number:
  US 20090104510A1
• Time in Patent Office: 1,317 Days
• Field of Search: None
• US Class Current: 429/61
• CPC Class Codes: G01R 31/54 Testing for continuity
• 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 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 50/55 on the same side of the cell
• CPC Class Codes: H01M 50/553 Terminals adapted for prismatic, pouch or rectangular cells
• CPC Class Codes: H01M 50/559 Terminals adapted for cells having curved cross-section, e.g. round, elliptic or button cells H01M50/553 takes precedence
• CPC Class Codes: H01M 50/562 characterised by the material
• CPC Class Codes: H01M 50/566 by welding, soldering or brazing
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• 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: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery management system includes one or more lithium ion cells in electrical connection, each said cell comprising: first and second working electrodes and one or more reference electrodes, each reference electrode electronically isolated from the working electrodes and having a separate tab or current collector exiting the cell and providing an additional terminal for electrical measurement; and a battery management system comprising a battery state-of-charge monitor, said monitor being operable for receiving information relating to the potential difference of the working electrodes and the potential of one or more of the working electrodes versus the reference electrode.

Claims

1. A battery, comprising:

first and second working electrodes separated by at least one separator, the first working electrode in electrical connection with a first terminal, and the second working electrode in electrical connection with a second terminal;

one or more reference electrodes; and

a can housing the working electrodes and the one or more reference electrodes, wherein the can is electrically isolated from the first and second terminals and is electrically connected to the one or more reference electrodes to provide terminals for the one or more reference electrodes,

wherein the battery is a lithium ion battery and the working electrodes comprise electroactive materials capable lithium uptake and release, and the one or more reference electrodes comprise lithium titanium oxide.

2. A battery, comprising:

first and second working electrodes separated by at least one separator, the first working electrode in electrical connection with a first terminal, and the second working electrode in electrical connection with a second terminal;

one or more reference electrodes; and

a can housing the working electrodes and the one or more reference electrodes, wherein the can is electrically isolated from the first and second terminals and is electrically connected to the one or more reference electrodes to provide terminals for the one or more reference electrodes,

wherein the battery is a lithium ion battery and the working electrodes comprise electroactive materials capable lithium uptake and release, and the one or more reference electrodes comprise lithium iron phosphate.

3. A battery, comprising:

first and second working electrodes separated by at least one separator, the first working electrode in electrical connection with a first terminal, and the second working electrode in electrical connection with a second terminal;

one or more reference electrodes; and

a can housing the working electrodes and the one or more reference electrodes, wherein the can is electrically isolated from the first and second terminals and is electrically connected to the one or more reference electrodes to provide terminals for the one or more reference electrodes,

wherein the battery is a lithium ion battery and the working electrodes comprise electroactive materials capable lithium uptake and release, and the active material for the one or more reference electrodes is coated onto at least part of a wall of the can.

4. A lithium ion battery system, comprising:

(a) one or more lithium ion cells in electrical connection, each said cell comprising;

first and second working electrodes separated by separator membranes, the working electrodes capable of lithium ion uptake and release, the first working electrode comprising a first electroactive layer on a first current collector, and the second working electrode comprising a second electroactive layer on a second current collector; and

one or more reference electrodes, each reference electrode electronically isolated from the working electrodes and having a separate tab or current collector exiting the cell and providing an additional terminal for electrical measurement;

(b) a battery management system comprising;

a battery state-of-charge monitor, said monitor being operable for receiving information relating to the potential difference of the working electrodes and the potential of one or more of the working electrodes vs. the one or more reference electrodes, and

a balancing module.

5. The battery system of claim 4, wherein the one or more lithium ion cells comprise cell pairs, and wherein the balancing module can evaluate the relative voltage levels of adjacent cell pairs and redistribute charge between adjacent cells to mitigate differences in the cell voltages of the pairs.