Impedance characteristic evaluation method and impedance characteristic evaluation apparatus

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for evaluating impedance characteristic that can analyze reaction resistance in detail by removing membrane resistance from the measured impedance characteristics.SOLUTION: A method for evaluating impedance characteristics includes the steps of: measuring the impedance of a battery while changing the measuring frequency; calculating a convergence value of a real component of the impedance as the membrane resistance of the battery when increasing the measuring frequency; and calculating the reaction resistance of the battery by subtracting the membrane resistance from the impedance of the battery. In the step of calculating the membrane resistance, the membrane resistance is calculated using fitting to an equivalent circuit, and a measurement system impedance component is added to the equivalent circuit.