Lithium ion battery control device, and lithium ion battery control method

A lithium ion battery control device for controlling charging or discharging of a lithium ion battery in which a degree of occlusion of lithium ions occluded in graphite of a negative electrode changes in accordance with an amount of stored power, the lithium ion battery control device comprising:

• an acquirer configured to acquire a determination index related to the degree of occlusion;
• and
• a controller configured to control charging the lithium ion battery with power or control discharging power from the lithium ion battery, so that the degree of occlusion is close to a degree of occlusion associated with a specific region when a region associated with the degree of occlusion is determined not to be the specific region, which includes LiC12 having a degree of occlusion represented by a first stoichiometric ratio value and does not include LiC6 having a degree of occlusion represented by a second stoichiometric ratio value on the basis of the determination index acquired by the acquirer,
• wherein the determination index is an index according to a capacity of the lithium ion battery, an SOC, a cell open circuit voltage of the lithium ion battery, an index according to a first correlation between the SOC and the cell open circuit voltage, or an index according to a second correlation between a capacity and a voltage, and
• wherein the controller is configured to further identify a region associated with the degree of occlusion of the lithium ion battery using a degree of deterioration of the lithium ion battery.

A lithium ion battery control method comprising:

• acquiring, by a computer, a determination index related to a degree of occlusion of a lithium ion battery in which the degree of occlusion of lithium ions occluded in graphite of a negative electrode changes in accordance with an amount of stored power;
• and
• controlling, by the computer, charging the lithium ion battery with power or discharging power from the lithium ion battery, so that the degree of occlusion is close to a degree of occlusion associated with a specific region when a region associated with the degree of occlusion is determined not to be the specific region, which includes LiC12 having a degree of occlusion represented by a first stoichiometric ratio value and does not include LiC6 having a degree of occlusion represented by a second stoichiometric ratio value on the basis of the acquired determination index,
• controlling, by the computer, the charging or the discharging, so that the degree of occlusion is close to the degree of occlusion associated with the specific region when the region associated with the degree of occlusion is determined to be:
• a first specific region including LiC6 having a degree of occlusion represented by a stoichiometric ratio, a second specific region including LiC18 having a degree of occlusion represented by a stoichiometric ratio, or a third specific region including a structure of a degree of occlusion greater than or equal to that of LiC27 having a degree of occlusion represented by a stoichiometric ratio,
• wherein a deterioration rate of the lithium ion battery decreases in an order of the first specific region, the second specific region, and the third specific region, and the specific region, and
• controlling, by the computer, the charging or the discharging, so that the degree of occlusion is close to the degree of occlusion associated with a region having a lower deterioration rate than the region associated with the degree of occlusion.