Title:
SECONDARY BATTERY SYSTEM AND METHOD FOR ESTIMATING DEGRADATION STATE OF SECONDARY BATTERY
Document Type and Number:
Japanese Patent JP2020046420
Kind Code:
A
Abstract:
To improve the accuracy of estimating the degradation state of a secondary battery in which charge/discharge hysteresis exists.SOLUTION: An ECU 100 calculates the surface stress σof a negative electrode active material from the internal lithium amount of the negative electrode active material on the basis of a prescribed active material model, and calculates an open-circuit potential change amount ΔOCP of the negative electrode active material from an open-circuit potential Uon the basis of the calculated surface stress σ. The ECU 100 corrects the negative electrode open-circuit potential Ucalculated by a degradation estimation process by the open-circuit potential change amount ΔOCP. The ECU 100 calculates three degradation parameters so that a measured OCV curve and an estimated CV curve specified on the basis of the negative electrode open-circuit potential Uafter correction approximately match. The open-circuit potential Uis an open-circuit potential of the negative electrode active material when there is no occurrence of a surface stress.SELECTED DRAWING: Figure 20
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Inventors:
TAKAHASHI KENJI
Application Number:
JP2019144833A
Publication Date:
March 26, 2020
Filing Date:
August 06, 2019
Export Citation:
Assignee:
TOYOTA MOTOR CORP
International Classes:
G01R31/392; G01R31/367; G01R31/3828; H01M4/36; H01M10/48; H02J7/00
Domestic Patent References:
| JP2011220917A | 2011-11-04 | |||
| JP2017190979A | 2017-10-19 | |||
| JP2017195727A | 2017-10-26 | |||
| JP2014139521A | 2014-07-31 |
Attorney, Agent or Firm:
Fukami patent office