Secondary battery system and method for controlling secondary battery
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsMotoyuki Oniki, Takashi Ogura, Risa Atarashi
Life of this patent
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Abstract
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.
Claims5
A secondary battery system comprising:
- a secondary battery having a negative electrode including a negative electrode active material into and from which lithium ions are inserted and desorbed;
- and
- a controller configured to calculate a negative electrode potential indicating a potential of the negative electrode relative to a reference potential,
- the controller being configured to
- calculate a surface potential of the negative electrode active material relative to the reference potential, using an amount of lithium ions inserted into the negative electrode active material obtained from a charging current to the secondary battery, and a diffusion coefficient of lithium ions inside the negative electrode active material, according to a battery model for calculating lithium concentration distribution inside the negative electrode active material,
- calculate a voltage drop amount associated with charging of the secondary battery, using the charging current to the secondary battery and a reaction resistance of the secondary battery,
- calculate the negative electrode potential by subtracting the voltage drop amount from the surface potential, and
- correct the negative electrode potential, using an SOC of the secondary battery, an average current in a charging period of the secondary battery, and an integrated current in the charging period.
A method for controlling a secondary battery, for calculating a negative electrode potential of the secondary battery having a negative electrode including a negative electrode active material into and from which lithium ions are inserted and desorbed, the method comprising:
- calculating a surface potential of the negative electrode active material, using an amount of lithium ions inserted into the negative electrode active material obtained from a charging current to the secondary battery, and a diffusion coefficient of lithium ions inside the negative electrode active material, according to a battery model for calculating lithium concentration distribution inside the negative electrode active material;
- calculating a voltage drop amount associated with charging of the secondary battery, using the charging current to the secondary battery and a reaction resistance of the secondary battery;
- calculating the negative electrode potential by subtracting the voltage drop amount from the surface potential;
- correcting the negative electrode potential, using an SOC of the secondary battery, an average current in a charging period of the secondary battery, and an integrated current in the charging period;
- and
- performing protection control for protecting the negative electrode when the negative electrode potential after correction falls below a reference potential.
Dependencies are inferred from the claim text.