Toyota Jidosha Kabushiki Kaisha

Motoyuki Oniki

Takashi Ogura

Risa Atarashi

An ECU calculates a surface potential of a negative electrode active material relative to a lithium reference potential, according to a battery model for calculating lithium concentration distribution inside the negative electrode active material. The ECU calculates a voltage drop amount associated with charging of a battery, using a charging current to the battery and a reaction resistance, and calculates a negative electrode potential by subtracting the voltage drop amount from the surface potential. The ECU corrects the negative electrode potential, using an SOC of the battery, an average current in a charging period of the battery, and an integrated current in the charging period.

Secondary battery system and method for controlling secondary battery

A temperature history of a lithium ion secondary battery is recorded; a SOC history of the lithium ion secondary battery is recorded; a deterioration degree (K) of a positive electrode of the lithium ion secondary battery is calculated based on the temperature history, the SOC history, and a first data table; a deterioration degree (K) of a negative electrode of the lithium ion secondary battery is calculated based on the temperature history, the SOC history, and a second data table; an amount of lithium trapped (TLi) in the lithium ion secondary battery is calculated based on the temperature history, the SOC history, and a third data table; and a deterioration degree of the lithium ion secondary battery is calculated based on the deterioration degree of the positive electrode, the deterioration degree of the negative electrode, and the amount of lithium trapped.

Growing community of inventors

Toyota, Japan

Motoyuki Oniki