BATTERY SYSTEM, MOBILE BODY AND POWER STORAGE SYSTEM PROVIDED WITH BATTERY SYSTEM, AND CONTROL METHOD FOR BATTERY SYSTEM

摘要

Provided is a battery system comprising a battery group that is configured from a plurality of lithium ion secondary batteries in which a solid-solution positive electrode active material that is represented by xLi₂Mo₃-(1-x)LiM'O₂ (wherein 0.3 x 0.7, M is at least one substance selected from among Mn, Ti, and Zr, and M' is at least one substance selected from among Ni, Co, Mn, Fe, Ti, Zr, Al, Mg, Cr, and V) is used in a positive electrode, and wherein: a first battery group that is connected to a charging/discharging target and a second battery group that is connected in parallel with the first battery group via a first switch are provided; the first switch is switched from a closed state to an open state when the charge state of the second battery group surpasses a predetermined SOC; and the first switch is switched from the open state to the closed state when the charge state of the first battery decreases and the difference between the open-circuit voltage of the first battery group and the open-circuit voltage of the second battery group is equal to or less than a predetermined value.