LITHIUM ION BATTERY SYSTEM

PROBLEM TO BE SOLVED: To provide a lithium ion battery system which is arranged so as to avoid the precipitation of metallic lithium on a negative electrode or the overdischarge on a positive electrode, and adequately replenishes lithium ions.SOLUTION: A lithium ion battery system 100 comprises: a lithium ion battery 120 having a positive electrode 122, a negative electrode 123, an electrolyte, and a third electrode 125 including, as an active material, a material including a lithium element; a connecting part 130 which can switch at least one of a combination of the third electrode and the positive electrode and a combination of the third electrode and the negative electrode between the state of electrically connecting between the electrodes and the state of electrically disconnecting between the electrodes; and a control part 110 for controlling the lithium ion battery. Until a physical quantity corresponding to the degree of concentration of lithium ions on the positive electrode or the negative electrode satisfies a predetermined condition after having switched from the state of electrically connecting between the electrodes to the state of electrically disconnecting between the electrodes, the control part inhibits the connecting part from again switching the at least one combination of the electrodes to the state of electrically connecting between the electrodes.SELECTED DRAWING: Figure 1 【課題】負極における金属リチウムの析出あるいは正極における過放電を避け、リチウムイオンの補充を適切に行うリチウムイオン電池システムを提供する。【解決手段】リチウムイオン電池システム１００であって、正極１２２と負極１２３と電解質とリチウム元素を含む材料を活物質とする第３電極１２５と、を有するリチウムイオン電池１２０と、第３電極と正極との間、および第３電極と負極との間の少なくとも一方を、電気的接続状態と電気的非接続状態との間で切り替えることが可能な接続部１３０と、リチウムイオン電池を制御する制御部１１０と、を含む。制御部は、接続部に対して、電気的接続状態から電気的非接続状態に切り替えた後において、正極上または負極上へのリチウムイオンの集中度合に対応する物理量が所定の条件を満たすまで再度電気的接続状態とすることを禁止する。【選択図】図１