SECONDARY CELL STATE DIAGNOSIS METHOD, AND STATE DIAGNOSIS DEVICE

• Main Authors: NISHIJIMA, Shun, HONKURA, Kohei
• Format: Patent
• Language: English; French; German
• Published: 02.10.2024
• Subjects: BASIC ELECTRIC ELEMENTS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SYSTEMS FOR STORING ELECTRIC ENERGY; TESTING

The present invention provides a secondary cell state diagnosis method and a secondary cell state diagnosis device that, even in a case where an active material having a potential that hardly changes in response to a change in a state of charge is used for the electrodes of a secondary cell, enable diagnosis of the deterioration of a secondary cell or each electrode. The secondary cell state diagnosis method includes evaluating, for one electrode of a positive electrode and a negative electrode, a deterioration state of the electrode on the basis of the relationship between a state of charge and an open-circuit potential of the positive electrode and the negative electrode and the relationship between a state of charge and an open-circuit voltage of the secondary cell; and evaluating, for the other electrode of the positive electrode and the negative electrode, the deterioration state of the electrode on the basis of the relationship between the state of charge and an internal resistance of the positive electrode and the negative electrode and the relationship between the state of charge and an internal resistance of the secondary cell. The secondary cell state diagnosis device includes an arithmetic unit that reads data indicating the relationship between a state of charge and an open-circuit voltage of the secondary cell and data indicating the relationship between the state of charge and an internal resistance of the secondary cell, and that evaluates a deterioration state of an electrode; and a storage unit that stores data indicating the relationship between a state of charge and an open-circuit voltage of a positive electrode and a negative electrode, and data indicating the relationship between the state of charge and an internal resistance of the positive electrode and the negative electrode.