Lithium ion battery cell having a capacitance sensor and method for monitoring the condition of a lithium ion battery cell of this type

• US 9,276,297 B2
• Filed: 06/05/2014
• Issued: 03/01/2016
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Original Assignee: Robert Bosch GmbH
• Inventors: Hald, Markus, Hore, Sarmimala
• Primary Examiner(s): RYAN, PATRICK J
• Assistant Examiner(s): McConnell, Wyatt
• Application Number:
  US14/296,556
• Publication Number:
  US 20140363705A1
• Time in Patent Office: 635 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01N 2027/222 for analysing gases
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• 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 10/4264 with capacitors
• 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 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2200/20 Pressure-sensitive devices
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 50/30 Arrangements for facilitating escape of gases
• CPC Class Codes: H01M 50/578 in response to pressure
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A lithium ion battery cell includes a graphite cathode, and an excess pressure valve. The excess pressure valve is configured to open in the presence of a predetermined battery cell internal pressure and discharging gases that have been produced inside the battery cell. Such gases are discharged together with graphite particles entrained in the gas. The battery cell further includes a capacitance sensor that has at least one capacitor positioned in the battery cell and configured such that the graphite particles that are entrained in the gas that is being discharged deposit themselves at least in part in a gap that is located between two electrodes of the capacitor and cause a change in the dielectric value in the gap. The change in the dielectric value causes a change in a capacitance of the capacitor.

Claims

1. A lithium ion battery cell, comprising:

a graphite cathode;

an excess pressure valve configured to open in a presence of a predetermined battery cell internal pressure and discharging gasses produced inside the lithium ion battery cell, wherein graphite particles are entrained in the discharging gasses; and

at least one capacitor that is positioned in the lithium ion battery cell and configured such that;

the graphite particles are deposited at least in part in a gap located between two electrodes of the at last one capacitor; and

the graphite particles being deposited at least in part in the gap causes change in a dielectric value of in the gap, wherein the change in the dielectric value causes a change in a capacitance of the at least one capacitor.

2. The lithium ion battery cell according to claim 1, further comprising:

a communication site configured to communicate with a battery management system; and

a measuring circuit configured to measure the capacitance of the at least one capacitor, ascertain a change in the capacitance, and provide information regarding an ascertained change in the capacitance via the communication site.

3. The lithium ion battery cell according to claim 1, further comprising a current supply circuit that is connected to or is configured to be connected to the two electrodes of the at least one capacitor, and is further configured to positively charge one of the two electrodes and negatively charge an other of the two electrodes.

4. The lithium ion battery cell according to claim 1, wherein the gap is at least one of an open gap and an air gap.

5. The lithium ion battery cell according to claim 1, wherein at least one of:

the two electrodes of the at least one capacitor have a substantially annular shape;

the two electrodes extend fully inside a housing of the lithium ion battery cell;

the at least one capacitor is positioned on an upper face of a cover of the lithium ion battery cell, and the two electrodes are positioned in a circular manner around the excess pressure valve; and

the at least one capacitor is positioned in a gas discharge duct situated on the excess pressure valve.

6. A method for monitoring a condition of a lithium ion battery cell that has a graphite cathode and an excess pressure valve, wherein graphite particles are entrained in discharging gasses produced inside the lithium ion battery cell, the method comprising:

obtaining a measurement of a capacitance of at least one capacitor positioned in the lithium ion battery cell and configured such that the graphite particles are deposited at least in part in a gap located between two electrodes of the capacitor and cause a change in a dielectric value in the gap, wherein a change in the dielectric value causes a change in the capacitance;

establishing a defective condition of the lithium ion battery cell in a presence of a change in the capacitance; and

discharging defective condition gas out of the lithium ion battery cell through an open excess pressure valve, wherein the excess pressure valve is configured to open in a presence of a predetermined battery cell internal pressure and the discharging gasses.

7. The method according to claim 6, further comprising:

ascertaining the change in the capacitance; and

providing the ascertained change in the capacitance via a communication site positioned on the lithium ion battery cell and configured to communicate with a battery management system.

8. The method according to claim 6, wherein one of the two electrodes is positively charged and an other of the two electrodes is negatively charged via a current supply circuit that is positioned in the lithium ion battery cell and that is connected to the two electrodes.

9. A battery system comprising:

a battery that includes a plurality of battery cells that respectively have;

a graphite cathode;

an excess pressure valve configured to open in a presence of a predetermined battery cell internal pressure and discharging gasses produced inside each battery cell, wherein graphite particles are entrained in the discharging gasses; and

at least one capacitor that is positioned in each battery cell and configured such that;

the graphite particles are deposited at least in part in a gap located between two electrodes of the at last one capacitor; and

the graphite particles being deposited at least in part in the gap causes change in a dielectric value of in the gap, wherein the change in the dielectric value causes a change in a capacitance of the at least one capacitor; and

a battery management system, wherein the battery system is configured to;

recognize and identify, via the battery management system, any of the plurality of battery cells as being defective in a presence of a change in the capacitance of a respective battery cell; and

discharge and bridge the respective battery cell that has been identified as defective.

10. The battery system according to claim 9, wherein the battery system is comprised by and configured to be used in a vehicle.