Lithium secondary battery and control system therefor, and method for detecting state of lithium secondary battery

摘要

There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode. A control system for a lithium secondary battery including a positive electrode, a negative electrode using silicon oxide as a negative electrode active material, and a lithium reference electrode having a reference potential with respect to the negative electrode includes measurement means for measuring a voltage V of the negative electrode with respect to the lithium reference electrode and a discharge capacity Q of the lithium secondary battery during discharge of the lithium secondary battery; generation means for generating a V-dQ/dV curve representing a relationship between dQ/dV, which is a proportion of an amount of change dQ in the discharge capacity Q to an amount of change dV in the voltage V, and the voltage V; calculation means for calculating an intensity ratio of two peaks appearing on the V-dQ/dV curve for two voltage values in the voltage V; and sensing means for sensing a state of the negative electrode utilizing the intensity ratio.

主权项

1. A control system for a lithium secondary battery comprising a positive electrode, a negative electrode using silicon oxide as a negative electrode active material, and means for obtaining a potential of the negative electrode with respect to a lithium reference electrode, the control system comprising:
measurement means for measuring a voltage V of the negative electrode with respect to the lithium reference electrode and a discharge capacity Q of the lithium secondary battery during discharge of the lithium secondary battery; generation means for generating a V-dQ/dV curve representing a relationship between dQ/dV, which is a proportion of an amount of change dQ in the discharge capacity Q to an amount of change dV in the voltage V, and the voltage V; calculation means for calculating an intensity ratio of two peaks appearing on the V-dQ/dV curve for two voltage values in the voltage V; and sensing means for sensing a state of the negative electrode utilizing the intensity ratio.