PERFORMANCE DETERIORATION DETECTING APPARATUS AND PERFORMANCE DETERIORATION DETECTING METHOD FOR ENERGY STORAGE DEVICE, AND ENERGY STORAGE SYSTEM

• US 20150301123A1
• Filed: 10/22/2013
• Published: 10/22/2015
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: GS Yuasa International Ltd. (GS Yuasa Corporation)
• Original Assignee: GS Yuasa International Ltd. (GS Yuasa Corporation)
• Inventors: Yamate, Shigeki, Tao, Yohei
• Granted Patent: US 9,547,046 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60Y 2200/91 Electric vehicles
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2400/112 Batteries
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• 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 10/48 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 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• 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

A performance deterioration detecting apparatus detects an initial state of sudden deterioration in performance of an energy storage device as a performance deterioration start state, and includes: a first acquiring unit configured to acquire a first maximum variation amount as a maximum value of a capacity variation amount that is a degree of variation in current carrying capacity relative to variation in voltage of the charged or discharged energy storage device, regarding a capacity-voltage property at a first time point, indicating relation between the capacity variation amount and the voltage; a second acquiring unit configured to acquire a second maximum variation amount as a maximum value of the capacity variation amount regarding the capacity-voltage property at a second time point after the first time point; and a performance deterioration determiner configured to determine that the energy storage device is in the performance deterioration start state at the second time point if a variation amount ratio as a ratio of the second maximum variation amount to the first maximum variation amount exceeds a predetermined value.

Claims

1. A performance deterioration detecting apparatus configured to detect an initial state of sudden deterioration in performance of an energy storage device as a performance deterioration start state, the apparatus comprising:

a first acquiring unit configured to acquire a first maximum variation amount as a maximum value of a capacity variation amount that is a degree of variation in current carrying capacity relative to variation in voltage of the charged or discharged energy storage device, regarding a capacity-voltage property at a first time point, indicating relation between the capacity variation amount and the voltage;

a second acquiring unit configured to acquire a second maximum variation amount as a maximum value of the capacity variation amount regarding the capacity-voltage property at a second time point after the first time point; and

a performance deterioration determiner configured to determine that the energy storage device is in the performance deterioration start state at the second time point if a variation amount ratio as a ratio of the second maximum variation amount to the first maximum variation amount exceeds a predetermined value.

2. The performance deterioration detecting apparatus according to claim 1, wherein

the performance deterioration determiner determines that the energy storage device is in the performance deterioration start state by determining at the second time point that the energy storage device is in an initial state of sudden deterioration in chargeable or dischargeable capacity of the energy storage device or in an initial state of sudden deterioration in input-output performance indicated by an input-output property of the energy storage device if the variation amount ratio exceeds the predetermined value.

3. The performance deterioration detecting apparatus according to claim 1, wherein

the performance deterioration determiner determines that the energy storage device is in the performance deterioration start state at the second time point if the variation amount ratio exceeds the predetermined value set to a range from 0.7 to 0.8.

4. The performance deterioration detecting apparatus according to claim 1, wherein

the first acquiring unit acquires the first maximum variation amount regarding the capacity-voltage property of the energy storage device in an initial state.

5. The performance deterioration detecting apparatus according to claim 1, wherein

the second acquiring unit charges or discharges the energy storage device at the second time point to acquire relation between the voltage and the current carrying capacity of the energy storage device, calculates the capacity variation amount by differentiating the current carrying capacity with respect to the voltage in accordance with the acquired relation, and acquires the capacity-voltage property indicating the relation between the calculated capacity variation amount and the voltage to acquire the second maximum variation amount.

6. The performance deterioration detecting apparatus according to claim 1, wherein

the performance deterioration determiner limits an upper limit charging voltage of the energy storage device if the performance deterioration determiner determines that the energy storage device is in the performance deterioration start state at the second time point.

7. The performance deterioration detecting apparatus according to claim 1, wherein

the performance deterioration determiner limits a maximum flowing current to the energy storage device if the performance deterioration determiner determines that the energy storage device is in the performance deterioration start state at the second time point.

8. The performance deterioration detecting apparatus according to claim 1, wherein

the energy storage device is a lithium-ion secondary battery including layered lithium transition metal oxide as a positive active material,

the first acquiring unit acquires the first maximum variation amount of the lithium-ion secondary battery, and

the second acquiring unit acquires the second maximum variation amount of the lithium-ion secondary battery.

9. An energy storage system comprising:

an energy storage device; and

the performance deterioration detecting apparatus according to claim 1, configured to detect an initial state of sudden deterioration in performance of the energy storage device as a performance deterioration start state.

10. A performance deterioration detecting method of detecting, with a computer, an initial state of sudden deterioration in performance of an energy storage device as a performance deterioration start state, the method comprising:

a first acquiring step of acquiring a first maximum variation amount as a maximum value of a capacity variation amount that is a degree of variation in current carrying capacity relative to variation in voltage of the charged or discharged energy storage device, regarding a capacity-voltage property at a first time point, indicating relation between the capacity variation amount and the voltage;

a second acquiring step of acquiring a second maximum variation amount as a maximum value of the capacity variation amount regarding the capacity-voltage property at a second time point after the first time point; and

a performance deterioration determining step of determining that the energy storage device is in the performance deterioration start state at the second time point if a variation amount ratio as a ratio of the second maximum variation amount to the first maximum variation amount exceeds a predetermined value.

11. An integrated circuit configured to detect an initial state of sudden deterioration in performance of an energy storage device as a performance deterioration start state, the integrated circuit comprising:

a first acquiring unit configured to acquire a first maximum variation amount as a maximum value of a capacity variation amount that is a degree of variation in current carrying capacity relative to variation in voltage of the charged or discharged energy storage device, regarding a capacity-voltage property at a first time point, indicating relation between the capacity variation amount and the voltage;

a second acquiring unit configured to acquire a second maximum variation amount as a maximum value of the capacity variation amount regarding the capacity-voltage property at a second time point after the first time point; and

a performance deterioration determiner configured to determine that the energy storage device is in the performance deterioration start state at the second time point if a variation amount ratio as a ratio of the second maximum variation amount to the first maximum variation amount exceeds a predetermined value.