Title:
CHARGE RATE ESTIMATION METHOD AND CHARGE RATE ESTIMATION DEVICE OF LITHIUM ION SECONDARY BATTERY
Document Type and Number:
Japanese Patent JP2023008597
Kind Code:
A
Abstract:
To provide a charge rate estimation method and a charge rate estimation device of a lithium ion secondary battery capable of precisely estimating a charge rate.SOLUTION: A charge rate estimation device includes: a memory that is built into a BMU 3 and stores an absolute value and an intercept of an inclination of a straight line for approximating a correlation between an imaginary number component of an AC impedance at a specific frequency from among multiple frequencies and a charge rate when measuring an AC impedance for each of multiple charge rates for a first lithium ion secondary battery, and a battery capacity of a secondary lithium ion secondary battery for which a charge rate is estimated; an MMU 24 for measuring an AC voltage generated between second lithium ion secondary batteries when an AC current having a specific frequency is applied to the secondary lithium ion secondary batteries; and the BMU 3 for calculating an AC impedance from an applied AC current a measured AC voltage and calculating a real number component and an imaginary number component of the calculated AC impedance. The charge rate is estimated by a predetermined operation.SELECTED DRAWING: Figure 7
Inventors:
MASUDA YOSUKE
Application Number:
JP2021112276A
Publication Date:
January 19, 2023
Filing Date:
July 06, 2021
Export Citation:
Assignee:
FURUKAWA BATTERY CO LTD
International Classes:
G01R31/382; G01R31/367; G01R31/378; G01R31/389; H01M4/505; H01M4/525; H01M4/58; H01M10/0525; H01M10/48; H02J7/00; H02J7/02
Attorney, Agent or Firm:
Suzue International Patent Office