Deterioration detecting method and deterioration suppressing method for rechargeable lithium batteries, deterioration detector, deterioration suppressor, battery pack, and charger

• US 8,102,152 B2
• Filed: 01/09/2008
• Issued: 01/24/2012
• Est. Priority Date: 01/11/2007
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ugaji, Masaya, Shirane, Takayuki, Inoue, Kaoru
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): Chung, Steve T
• Application Number:
  US12/161,104
• Publication Number:
  US 20100156351A1
• Time in Patent Office: 1,476 Days
• Field of Search: 320/132, 320/134, 320/149, 320/DIG.21, 324/430, 324/433, 324/434, 324/426, 429/90, 429/160
• US Class Current: 320/134
• CPC Class Codes: G01R 31/378 specially adapted for the type of battery or accumulator
• 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 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• 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 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

According to a deterioration detecting method for rechargeable lithium batteries, battery voltages of a rechargeable lithium battery before and after the completion of charging or discharging are measured. An evaluation value is calculated based on the measured battery voltages. This evaluation value is compared with a reference value of the rechargeable lithium battery stored in advance. A deterioration level of the rechargeable lithium battery is estimated based on this comparison result. In addition, further deterioration can be suppressed by controlling charging and discharging of the rechargeable lithium battery based on the estimated deterioration level.

Claims

1. A deterioration detecting method for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration detecting method comprising;

detecting

a group of a closed-circuit charge cutoff voltage and an open-circuit voltage after charging of the rechargeable lithium battery;

calculating an evaluation value based on the detected group of voltages;

comparing the evaluation value and a reference value stored in advance to have a comparison result; and

estimating a deterioration level of the rechargeable lithium battery based on the comparison result,

wherein the evaluation value is an apparent resistance R₁ at completion of charging, the apparent resistance R₁ calculated based on a relational expression of;

R₁=Δ

V₁/I₁,

where Δ

V₁ is a difference between the closed-circuit charge cutoff voltage and the open-circuit voltage after charging, and

I₁ is a closed circuit charge cutoff current.

2. A deterioration suppressing method for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressing method comprising;

detecting

a group of a closed-circuit charge cutoff voltage and an open-circuit voltage after charging of the rechargeable lithium battery;

calculating an evaluation value based on the detected group of the voltages;

comparing the evaluation value and a reference value stored in advance to have a comparison result;

estimating a deterioration level of the rechargeable lithium battery based on the comparison result; and

controlling charging of the rechargeable lithium battery based on the estimated deterioration level,

wherein the evaluation value is an apparent resistance R₁ at completion of charging, the apparent resistance R₁ calculated based on a relational expression of;

R₁=Δ

V₁/I₁,

where Δ

V₁ is a difference between the closed-circuit charge cutoff voltage and the open-circuit voltage after charging, and

I₁ is a closed circuit charge cutoff current.

3. The deterioration suppressing method for a rechargeable lithium battery according to claim 2, wherein a charge time is shortened to control charging.

4. The deterioration suppressing method for a rechargeable lithium battery according to claim 2, wherein the closed-circuit charge cutoff voltage is reduced to control charging.

5. A deterioration suppressing method for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressing method comprising;

detecting

a group of a closed-circuit charge cutoff voltage and an open-circuit voltage after charging of the rechargeable lithium battery;

calculating an evaluation value based on the detected group of the voltages;

comparing the evaluation value and a reference value stored in advance to have a comparison result;

estimating a deterioration level of the rechargeable lithium battery based on the comparison result; and

controlling discharging of the rechargeable lithium battery based on the estimated deterioration level,

wherein the evaluation value is an apparent resistance R₁ at completion of charging, the apparent resistance R₁ calculated based on a relational expression of;

R₁=Δ

V₁/I₁,

where Δ

V₁ is a difference between the closed-circuit charge cutoff voltage and the open-circuit voltage after charging, and

I₁ is a closed circuit charge cutoff current.

6. The deterioration suppressing method for a rechargeable lithium battery according to claim 5, wherein a discharge time is shortened to control discharging.

7. A deterioration detector for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration detector comprising;

a detector configured to detect

a group of a closed-circuit charge cutoff voltage and an open-circuit voltage after charging of the rechargeable lithium battery;

a calculator configured to calculate an evaluation value based on the detected group of voltages;

a comparator configured to compare the evaluation value with a reference value stored in advance to have a comparison result; and

a determiner configured to estimate a deterioration level of the rechargeable battery based on the comparison result in the comparator,

wherein the evaluation value is an apparent resistance R₁ at completion of charging, the apparent resistance R₁ calculated based on a relational expression of;

R₁=Δ

V₁/I₁,

where Δ

V₁ is a difference between the closed-circuit charge cutoff voltage and the open-circuit voltage after charging, and

I₁ is a closed circuit charge cutoff current.

8. A deterioration suppressor for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressor comprising;

a detector configured to detect

a group of a closed-circuit charge cutoff voltage and an open-circuit voltage after charging of the rechargeable lithium battery;

a calculator configured to calculate an evaluation value based on the detected group of voltages;

a comparator configured to compare the evaluation value with a reference value already stored to have a comparison result;

a determiner configured to estimate a deterioration level of the rechargeable battery based on the comparison result in the comparator; and

a controller configured to control charging of the rechargeable lithium battery based on the deterioration level estimated by the determiner,

wherein the evaluation value is an apparent resistance R₁ at completion of charging, the apparent resistance R₁ calculated based on a relational expression of;

R₁=Δ

V₁/I₁,

where Δ

V₁ is a difference between the closed-circuit charge cutoff voltage and the open-circuit voltage after charging, and

I₁ is a closed circuit charge cutoff current.

9. A battery pack comprising the deterioration suppressor according to claim 8 and a rechargeable lithium battery.

10. A charger comprising the deterioration suppressor according to claim 8 and a charging part configured to charge a rechargeable lithium battery.

11. A deterioration suppressor for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressor comprising;

a detector configured to detect

a group of a closed-circuit charge cutoff voltage and an open-circuit voltage after charging of the rechargeable lithium battery;

a calculator configured to calculate an evaluation value based on the detected group of voltages;

a comparator configured to compare the evaluation value with a reference value stored in advance to have a comparison result;

a determiner configured to estimate a deterioration level of the rechargeable battery based on the comparison result in the comparator; and

a controller configured to control discharging of the rechargeable lithium battery based on the deterioration level estimated by the detector,

wherein the evaluation value is an apparent resistance R₁ at completion of charging, the apparent resistance R₁ calculated based on a relational expression of;

R₁=Δ

V₁/I₁,

where Δ

V₁ is a difference between the closed-circuit charge cutoff voltage and the open-circuit voltage after charging, and

I₁ is a closed circuit charge cutoff current.

12. A battery pack comprising the deterioration suppressor according to claim 11 and a rechargeable lithium battery.

13. A deterioration detecting method for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration detecting method comprising;

detecting

a group of a closed-circuit discharge cutoff voltage and an open-circuit voltage after discharging of the rechargeable lithium battery;

calculating an evaluation value based on the detected group of voltages;

comparing the evaluation value and a reference value stored in advance to have a comparison result; and

estimating a deterioration level of the rechargeable lithium battery based on the comparison result,

wherein the evaluation value is an apparent resistance R₂ at completion of discharging,

the apparent resistance R₂ calculated based on a relational expression of;

R₂=Δ

V₂/I₂,

where Δ

V₂ is a difference between the closed-circuit discharge cutoff voltage and the open-circuit voltage after discharging, and

I₂ is a closed-circuit discharge cutoff current.

14. A deterioration suppressing method for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressing method comprising;

detecting

a group of a closed-circuit discharge cutoff voltage and an open-circuit voltage after discharging of the rechargeable lithium battery;

calculating an evaluation value based on the detected group of the voltages;

comparing the evaluation value and a reference value stored in advance to have a comparison result;

estimating a deterioration level of the rechargeable lithium battery based on the comparison result; and

controlling charging of the rechargeable lithium battery based on the estimated deterioration level,

wherein the evaluation value is an apparent resistance R₂ at completion of discharging, the apparent resistance R₂ calculated based on a relational expression of;

R₂=Δ

V₂/I₂,

where Δ

V₂ is a difference between the closed-circuit discharge cutoff voltage and the open-circuit voltage after discharging, and

I₂ is a closed-circuit discharge cutoff current.

15. The deterioration suppressing method for a rechargeable lithium battery according to claim 14, wherein a charge time is shortened to control charging.

16. A deterioration suppressing method for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressing method comprising;

detecting

a group of a closed-circuit discharge cutoff voltage and an open-circuit voltage after discharging of the rechargeable lithium battery;

calculating an evaluation value based on the detected group of the voltages;

comparing the evaluation value and a reference value stored in advance to have a comparison result;

estimating a deterioration level of the rechargeable lithium battery based on the comparison result; and

controlling discharging of the rechargeable lithium battery based on the estimated deterioration level,

wherein the evaluation value is an apparent resistance R₂ at completion of discharging, the apparent resistance R₂ calculated based on a relational expression of;

R₂=Δ

V₂/I₂,

where Δ

V₂ is a difference between the closed-circuit discharge cutoff voltage and the open-circuit voltage after discharging, and

I₂ is a closed-circuit discharge cutoff current.

17. The deterioration suppressing method for a rechargeable lithium battery according to claim 16, wherein a discharge time is shortened to control discharging.

18. The deterioration suppressing method for a rechargeable lithium battery according to claim 16, wherein the closed-circuit discharge cutoff voltage is increased to control discharging.

19. A deterioration detector for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration detector comprising;

a detector configured to detect

a group of a closed-circuit discharge cutoff voltage and an open-circuit voltage after discharging of the rechargeable lithium battery;

a calculator configured to calculate an evaluation value based on the detected group of voltages;

a comparator configured to compare the evaluation value with a reference value stored in advance to have a comparison result; and

a determiner configured to estimate a deterioration level of the rechargeable battery based on the comparison result in the comparator,

wherein the evaluation value is an apparent resistance R₂ at completion of discharging, the apparent resistance R₂ calculated based on a relational expression of;

R₂=Δ

V₂/I₂,

where Δ

V₂ is a difference between the closed-circuit discharge cutoff voltage and the open-circuit voltage after discharging, and

I₂ is a closed-circuit discharge cutoff current.

20. A deterioration suppressor for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressor comprising;

a detector configured to detect

a group of a closed-circuit discharge cutoff voltage and an open-circuit voltage after discharging of the rechargeable lithium battery;

a calculator configured to calculate an evaluation value based on the detected group of voltages;

a comparator configured to compare the evaluation value with a reference value already stored to have a comparison result;

a determiner configured to estimate a deterioration level of the rechargeable battery based on the comparison result in the comparator; and

a controller configured to control charging of the rechargeable lithium battery based on the deterioration level estimated by the determiner,

wherein the evaluation value is an apparent resistance R₂ at completion of discharging, the apparent resistance R₂ calculated based on a relational expression of;

R₂=Δ

V₂/I₂,

where Δ

V₂ is a difference between the closed-circuit discharge cutoff voltage and the open-circuit voltage after discharging, and

I₂ is a closed-circuit discharge cutoff current.

21. A battery pack comprising the deterioration suppressor according to claim 20 and a rechargeable lithium battery.

22. A charger comprising the deterioration suppressor according to claim 20 and a charging part configured to charge a rechargeable lithium battery.

23. A deterioration suppressor for a rechargeable lithium battery, the rechargeable lithium battery comprising:

a positive electrode having a positive active material that absorbs and emits a lithium ion;

a negative electrode having a negative active material that contains at least one of elements of silicon and tin; and

an electrolyte having lithium-ion conductivity, the electrolyte being provided between the positive electrode and the negative electrode;

the deterioration suppressor comprising;

a detector configured to detect

a group of a closed-circuit discharge cutoff voltage and an open-circuit voltage after discharging of the rechargeable lithium battery;

a calculator configured to calculate an evaluation value based on the detected group of voltages;

a comparator configured to compare the evaluation value with a reference value stored in advance to have a comparison result;

a determiner configured to estimate a deterioration level of the rechargeable battery based on the comparison result in the comparator; and

a controller configured to control discharging of the rechargeable lithium battery based on the deterioration level estimated by the detector,

wherein the evaluation value is an apparent resistance R₂ at completion of discharging,

the apparent resistance R₂ calculated based on a relational expression of;

R₂=Δ

V₂/I₂,

where Δ

V₂ is a difference between the closed-circuit discharge cutoff voltage and the open-circuit voltage after discharging, and

I₂ is a closed-circuit discharge cutoff current.

24. A battery pack comprising the deterioration suppressor according to claim 23 and a rechargeable lithium battery.