| CPC G01R 31/3648 (2013.01) [G01R 31/367 (2019.01); G01R 31/385 (2019.01); H01M 10/484 (2013.01); H01M 4/587 (2013.01); H01M 10/0525 (2013.01); H01M 10/48 (2013.01); Y02E 60/10 (2013.01)] | 7 Claims |
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1. A battery characteristic estimation device comprising a storage medium that stores computer-readable instructions, and a processor coupled to the storage medium, the processor executing the computer-readable instructions to:
acquire time-series data of at least a voltage and current of a secondary battery mounted on a vehicle and having a positive electrode containing a positive electrode active material and a negative electrode containing a negative electrode active material;
store a reference positive electrode OCP curve, which indicates an open circuit voltage change with respect to a discharge capacity of the positive electrode, and a reference negative electrode OCP curve, which indicates an open circuit voltage change with respect to a discharge capacity of the negative electrode;
convert the reference positive electrode OCP curve into a positive electrode OCP curve in accordance with a first parameter group, convert the reference negative electrode OCP curve into a negative electrode OCP curve in accordance with a second parameter group, and estimate an OCV curve, which indicates an open circuit voltage change with respect to a capacity change of the secondary battery, on the basis of a difference between the positive electrode OCP curve and the negative electrode OCP curve;
optimize the first parameter group and the second parameter group such that a value of an error function representing an error between the estimated OCV curve and the time-series data is equal to or smaller than a predetermined value; and
provide, to the vehicle, information related to the estimated OCV curve after optimization as information indicating a characteristic of the secondary battery, and display the information on a display device of the vehicle,
wherein the first parameter group includes a positive electrode scaling factor for converting a width of a reference discharge capacity of a positive electrode into a width of an actual discharge capacity and a positive electrode shift amount, which is a shift amount in a discharge capacity direction from the reference positive electrode OCP curve to the positive electrode OCP curve,
wherein the second parameter group includes a negative electrode scaling factor for converting a width of a reference discharge capacity of a negative electrode into a width of an actual discharge capacity and a negative electrode shift amount, which is a shift amount in a discharge capacity direction from the reference negative electrode OCP curve to the negative electrode OCP curve, and
wherein the processor optimizes the first parameter group and the second parameter group by constraining a relationship between the negative electrode scaling factor and the negative electrode shift amount using a specific function.
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