Lithium-ion energy store and method for detecting a depth of discharge and/or a state of charge of a lithium-ion energy store

• US 10,067,191 B2
• Filed: 09/30/2014
• Issued: 09/04/2018
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Butzmann, Stefan
• Primary Examiner(s): Berhanu, Samuel
• Assistant Examiner(s): Kebede, Tessema
• Application Number:
  US15/028,893
• Publication Number:
  US 20160252580A1
• Time in Patent Office: 1,435 Days
• Field of Search: 324426
• CPC Class Codes: G01R 31/364 Battery terminal connectors with integrated measuring arrangements
• CPC Class Codes: G01R 31/378 specially adapted for the type of battery or accumulator
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/48 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 2004/025 with shapes other than plane or cylindrical
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The invention relates to a lithium-ion energy store (1), comprising an electrode (2, 3) having a main segment (2) and having a measurement segment (3) electrically isolated from the main segment (2), a counter-electrode (4), and a separator (5) between the electrode (2, 3) and the counter-electrode (4), wherein a measuring cell (3, 4), which forms part of the lithium-ion energy store (1), comprises the measuring segment (3) of the electrode (2, 3), a counter-electrode measuring segment, which is opposite the measuring segment (3) of the electrode (2, 3) with respect to the separator (5), and a segment of the separator (5) in arranged between the measuring segment (3) of the electrode (2, 3) and the counter-electrode measuring segment, and a main cell (2, 4), which forms part of the lithium-ion energy store (1), comprises the main segment (2) of the electrode (2, 3), a counter-electrode in main segment, which is opposite the main segment (2) of the electrode (2, 3) with respect to the separator (5), and a segment of the separator (5) arranged between the main segment (2) of the electrode (2, 3) and the counter-electrode main segment, wherein the lithium-ion energy store (1) has a measuring device (110) for a depth of discharge and/or a state of charge of the measuring cell (3, 4).

Claims

1. A lithium ion energy storage device comprising:

an electrode having a main section and a measuring section that is electrically separated from the main section,

a mating electrode including a mating electrode main section and a mating electrode measuring section that is electrically separated from the mating electrode main section,

a separator between the electrode and the mating electrode,

a measuring cell defined by the measuring section of the electrode and the mating electrode measuring section that lies opposite the measuring section of the electrode and is separated from the measuring section of the electrode by the separator,

a main cell defined by the main section of the electrode and the mating electrode main section that lies opposite the main section of the electrode and is separated from the main section of the electrode by the separator, and

a measuring device for measuring a depth of discharge, a state of charge, or both a depth of discharge and a state of charge of the measuring cell by charging or discharging the measuring cell without charging or discharging the main cell.

2. The lithium ion energy storage device as claimed in claim 1, wherein the measuring device comprises a current source that is connected between the measuring section and the mating electrode (II), and a voltage ascertaining device (02) that is connected to the measuring section and the mating electrode, and a time measuring device, with which it is possible to measure a charging period a discharging period, or both depth of discharge and a state of charge.

3. The lithium ion energy storage device as claimed in claim 2, wherein the voltage ascertaining device is a comparator and the end time of the time measuring procedure can be defined on the basis of the output signal of said voltage ascertaining device.

4. The lithium ion energy storage device as claimed in claim 3, wherein the measuring device of said lithium ion energy storage device comprises a reference voltage source that is connected to the comparator.

5. The lithium ion energy storage device as claimed in claim 2, wherein the time measuring device operates in a pulsed manner.

6. The lithium ion energy storage device as claimed in claim 2, wherein the current source is designed so as to output a constant current and/or can be switched on and switched off.

7. A method for ascertaining a depth of discharge, a state of charge, or both a depth of discharge and a state of charge of a lithium ion energy storage device, the method comprising

starting a flow of a charging current or a discharging current into a measuring cell without starting the flow of the charging current into a main cell, the measuring cell defined as a measuring section of an electrode of the lithium ion energy storage device electrically separated from a main section of the electrode and a measuring section of a mating electrode of the lithium ion energy storage device electrically separated from a main section of the mating electrode, the measuring section of the electrode and the measuring section of the mating electrode separated by a separator and the main cell defined as the main section of the electrode and the main section of the mating electrode,

charging or discharging the measuring cell until a reference voltage is achieved,

determining a charging period or discharging period of the measuring cell, and

determining a state of charge, a depth of discharge, or both a state of charge and a depth of discharge of the measuring cell based upon the charging period or discharging period of the measuring cell.

8. The method as claimed in claim 7, wherein in a first step a time measuring procedure is commenced at the start time by means of a time measuring device, and in a second step the time measuring procedure is terminated once a predefined voltage of the measuring cell is achieved.

9. The method as claimed in claim 7, wherein the state of charge or the depth of discharge of the main cell is inferred from the state of charge, the depth of discharge, or both a depth of discharge and a state of charge of the measuring cell at the start time.