US 2016/0239586 A1 · LIFETIME PREDICTION METHOD AND SYSTEM OF LITHIUM-ION BATTERY

Abstract

In a method of predicting a lifetime of a lithium-ion battery, measurement data ηexp of a capacity retention η vs the number of charge and discharge cycles Ni in the lithium-ion battery is first input. Then, a physical parameter p such as a reaction velocity factor for allowing solvent molecules reduced and decomposed by a negative electrode to react with a lithium ion dissolved in a electrolyte solution to generate a precursor of a solid electrolyte inter-phase in the physical model is set in a physical model. Calculation data ηth of the capacity retention η vs the number of charge and discharge cycles Ni in the physical model is calculated with the use of two or more diffusion coefficients DSEI and DpNE to the solvent molecules. A mean square error Oth (DSEI, DpNE) of the measurement data ηexp and the calculation data ηth in the number of charge and discharge cycles Ni are calculated. Then, values DSEI and DpNE of the diffusion coefficients where the mean square error Oth (DSEI, DpNE) is minimal are selected.

Claims15

Dependent claims

A method of predicting a lifetime of a lithium-ion battery with the use of a physical model corresponding to the lithium-ion battery in which the lithium-ion battery includes a positive electrode, a negative electrode, and an electrolyte solution, the method comprising the steps of:

setting the physical model;
inputting measurement data ηexp of a capacity retention η vs the number of charge and discharge cycles Ni in the lithium-ion battery;
setting a physical parameter p such as a reaction velocity factor for allowing solvent molecules reduced and decomposed by the negative electrode to react with a lithium ion dissolved in the electrolyte solution to generate a precursor of a solid electrolyte inter-phase in the physical model;
calculating calculation data ηth of the capacity retention η vs the number of charge and discharge cycles Ni with the use of two or more diffusion coefficients DSEI and DpNE to the solvent molecules, using the physical parameter of the physical model;
calculating a mean square error Oth (DSEI, DpNE) of the measurement data ηexp and the calculation data ηth in the number of charge and discharge cycles Ni;
and
selecting values DSEI and DpNE of the diffusion coefficients where the mean square error Oth(DSEI, DpNE) is minimal from the two or more kinds of diffusion coefficients DSEI and DpNE.

4 more elements

wherein in the physical model, a reduced product obtained by reducing and decomposing organic solvent molecules in an end surface area of the negative electrode reacts with lithium ions to produce a precursor pSEI of a solid electrolyte inter-phase, and
wherein a charge and discharge cycle characteristic of the capacity retention is predicted by solving a simultaneous differential equation of the capacity retention and the solid electrolyte inter-phase depth with the use of a flux density of the organic solvent molecules that disperse into two areas of the solid electrolyte inter-phase area and a porous negative electrode area.

A lifetime prediction system of a lithium-ion battery, comprising:

a CPU that executes arithmetic processing;
a computing device having a program executed by the CPU, and a storage device that stores data;
an input device for inputting the data to the computing device;
a setting unit, an arithmetic unit, and a determination/selection unit of an arithmetic result;
and
an output device for outputting the arithmetic result in the computing device, in which the lithium-ion battery includes a positive electrode, a negative electrode, and an electrolyte solution, wherein
the input device inputs measurement data rff of a capacity retention η vs the number of charge and discharge cycles Ni in the lithium-ion battery of a real equipment,
the setting unit sets a physical parameter p such as a reaction velocity factor for allowing solvent molecules reduced and decomposed by the negative electrode to react with a lithium ion dissolved in the electrolyte solution to generate a precursor of a solid electrolyte inter-phase in the physical model,
the arithmetic unit calculates calculation data ηth of the capacity retention η vs the number of charge and discharge cycles Ni with the use of two or more diffusion coefficients DSEI and DpNE to the solvent molecules, and also calculates a mean square error Oth(DSEI, DpNE) of the measurement data ηexp and the calculation data ηth in the number of charge and discharge cycles Ni,
the determination/selection unit of the arithmetic result selects values DSEI and DpNE of the diffusion coefficients where the mean square error Oth(DSEI, DPNE) is minimum, and
the output device outputs the selection result.

8 more elements

Dependencies are inferred from the claim text.

Lifetime prediction method and system of lithium-ion battery

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Lifetime prediction method and system of lithium-ion battery

Life of this patent

Abstract

Claims15