Rechargeable battery evaluation device, rechargeable battery evaluation method, and rechargeable battery evaluation system

Patent metadata

Field	Value
Publication number	US-2021178927-A1
Application number	US-202117249344-A
Country	US
Kind code	A1
Filing date	Feb 26, 2021
Priority date	Sep 6, 2019
Publication date	Jun 17, 2021
Grant date	—

Abstract

There is provided a rechargeable battery evaluation device including: a charging controller configured to switch charging current of a rechargeable battery being charged with first current to second current; and a first state estimator configured to estimate a state of the rechargeable battery based on a feature of change in at least one of a voltage and a charging amount of the rechargeable battery due to switching from the charging current to the second current.

First claim

1 . A rechargeable battery evaluation device comprising:
a charging controller configured to switch charging current of a rechargeable battery being charged with first current to second current; and a first state estimator configured to estimate a state of the rechargeable battery based on a feature of change in at least one of a voltage and a charging amount of the rechargeable battery due to switching from the charging current to the second current.

2 . The rechargeable battery evaluation device according to claim 1 , wherein
the charging controller performs charging with the second current in a first duration, the first state estimator
calculates a first voltage in the first duration, and
calculates a second voltage in the first duration assumed that charging is performed with the first current in the first duration, and
the feature includes the difference between the first voltage and the second voltage.

3 . The rechargeable battery evaluation device according to claim 2 , wherein the second voltage is an average value between a voltage before start of the first duration and a voltage after end of the first duration.

4 . The rechargeable battery evaluation device according to claim 1 , wherein
the first state estimator
calculates a charging-amount change amount that is a difference between a charging amount of the rechargeable battery before charging with the second current and a charging amount of the rechargeable battery after charging with the second current, and
calculates a voltage change amount that is a difference between a voltage of the rechargeable battery before charging with the second current and a voltage of the rechargeable battery after charging with the second current, and
the feature is based on at least one of the voltage change amount and the charging-amount change amount.

5 . The rechargeable battery evaluation device according to claim 4 , wherein the feature includes a ratio of the voltage change amount and the charging-amount change amount.

6 . The rechargeable battery evaluation device according to claim 1 , further comprising an estimation result evaluator configured to
specify, based on a plurality of pieces of first charging data in each of which a charging amount and a voltage are related with each other for a plurality of states, first charging data corresponding to the state estimated by the first state estimator, and specify a reference charging amount that is a charging amount corresponding to an evaluation target voltage in the specified first charging data, wherein the first state estimator specifies an evaluation target charging amount that is a charging amount of the rechargeable battery corresponding to the evaluation target voltage, and estimates the state of the rechargeable battery based on a difference between the reference charging amount and the evaluation target charging amount.

7 . The rechargeable battery evaluation device according to claim 6 , wherein
the first state estimator calculates a first temperature based on a measured value of the temperature of the rechargeable battery, the plurality of pieces of first charging data are associated with a plurality of battery temperatures, and the estimation result evaluator specifies the first charging data based on the first temperature and the state.

8 . The rechargeable battery evaluation device according to claim 6 , further comprising a data acquirer configured to acquire, from the rechargeable battery, information including an initial charging amount that is a charging amount of the rechargeable battery before charging, wherein
the state of the rechargeable battery is estimated based on the initial charging amount indicated by the information, the initial charging amount indicated by the information is corrected based on a difference between the reference charging amount and the evaluation target charging amount, and the state of the rechargeable battery is estimated based on the initial charging amount after the correction.

9 . The rechargeable battery evaluation device according to claim 1 , further comprising:
an estimation result evaluator configured to specify, based on a plurality of pieces of second charging data in each of which a charging amount and a voltage are related with each other for a plurality of states, second charging data corresponding to the estimated state; a data acquirer configured to acquire information indicating the initial state of the rechargeable battery; and a second state estimator configured to estimate an internal state of the rechargeable battery based on the information and the second charging data.

10 . The rechargeable battery evaluation device according to claim 9 , wherein
the first state estimator calculates a first temperature based on a measured value of the temperature of the rechargeable battery, the plurality of pieces of second charging data are associated with a plurality of battery temperatures, and the estimation result evaluator specifies the second charging data based on the first temperature and the state.

11 . The rechargeable battery evaluation device according to claim 1 , wherein the charging controller generates the second current by adding third current to the first current.

12 . The rechargeable battery evaluation device according to claim 1 , further comprising a charging driver configured to charge the rechargeable battery.

13 . The rechargeable battery evaluation device according to claim 1 , wherein the second current is square-wave current.

14 . The rechargeable battery evaluation device according to claim 1 , wherein the first state estimator estimates the state of the rechargeable battery based on measurement data of the rechargeable battery.

15 . The rechargeable battery evaluation device according to claim 1 , wherein the state of the rechargeable battery is a degradation state of the rechargeable battery.

16 . A rechargeable battery evaluation method comprising:
switching charging current of a rechargeable battery being charged with first current to second current; and estimating a state of the rechargeable battery based on a feature of change in the voltage or charging amount of the rechargeable battery due to switching from the charging current to the second current.

17 . The rechargeable battery evaluation method according to claim 16 , comprising;
charging with the second current is performed in a first duration, calculating a first voltage in the first duration, calculating a second voltage in the first duration assumed that charging is performed with the first current in the first duration, and the feature includes a difference between the first voltage and the second voltage.

18 . The rechargeable battery evaluation method according to claim 17 , wherein the second voltage is an average value between a voltage before start of the first duration and a voltage after end of the first duration.

19 . The rechargeable battery evaluation method according to claim 16 , comprising;
calculating a charging-amount change amount that is a difference between a charging amount of the rechargeable battery before charging with the second current and a charging amount of the rechargeable battery after charging with the second current, calculating a voltage change amount that is a difference between a voltage of the rechargeable battery before charging with the second current and a voltage of the rechargeable battery after charging with the second current, and the feature is based on at least one of the v

Assignees

• Yamamoto Takahiro
• Koiwa Kaoru
• Hatano Hisaaki
• Fujiwara Kenichi
• Maruchi Kohei
• Takazawa Koji
• Isozaki Yoshiyuki
• Egusa Shun
• Morita Tomokazu
• Toshiba Kk

Inventors

• Yamamoto Takahiro
• Koiwa Kaoru
• Hatano Hisaaki
• Fujiwara Kenichi
• Maruchi Kohei
• Takazawa Koji
• Isozaki Yoshiyuki
• Egusa Shun
• Morita Tomokazu

Classifications

• H02J7/977

  of the battery · CPC title

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/963

  in response to battery voltage gradient · CPC title