METHOD FOR CONTROLLING CHARGE OF LITHIUM ION BATTERY, CHARGE CONTROLLER OF LITHIUM ION BATTERY, AND LITHIUM ION BATTERY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a lithium ion battery which enables the suppression of degradation of a positive electrode per se by suppressing the rise in a positive electrode potential.SOLUTION: A method for controlling the charge of a lithium ion battery including a positive electrode active material having an olivine type crystal structure comprises: a charging step (step S11, S22) for charging the battery to a target voltage according to a constant current-constant voltage charging method; a negative electrode potential evaluation step (step S20) for evaluating a change in potential of a negative electrode; and a voltage setting step (step S21) for making the setting of lowering the target voltage based on the potential change of the negative electrode evaluated in the negative electrode potential evaluation step. According to this arrangement, even if the negative electrode potential is changed in response to the increase in the number of times of charging the battery, the aging or the like, a voltage for charging the battery from the target voltage to a set voltage is lowered and as such, the charging is made unsusceptible to the increase in the number of times of charging the battery, the aging or the like, and the rise in positive electrode potential can be suppressed. Therefore, the degradation of a positive electrode per se can be suppressed.SELECTED DRAWING: Figure 4