METHOD AND APPARATUS FOR DETECTING CELL DETERIORATION IN AN ELECTROCHEMICAL CELL OR BATTERY
First Claim
1. Apparatus for determining a physical property of an electrochemical cell or battery comprising:
- measuring circuitry adapted to apply time-varying electrical excitation to said cell or battery, to sense time-varying electrical response to said excitation, and to utilize said excitation and said response to determine components of complex immittance at n+m discrete frequencies, where n is an integer equal to or greater than two and m is an integer equal to or greater than one;
computation circuitry responsive to said complex immittance components and adapted to evaluate the elements of a 2n-element equivalent circuit model from said complex immittance components at said n discrete frequencies, adapted to calculate the complex immittance components of said model at said m discrete frequencies, and adapted to mathematically compare said calculated components with said measured immittance components at said m discrete frequencies, the results of said comparison being related to said physical property.
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Accused Products
Abstract
A testing device detects and quantifies cell deterioration of an electrochemical cell or battery. The device contains measuring circuitry adapted to apply time-varying electrical excitation to said cell or battery, to sense time-varying electrical response to said excitation, and to utilize said excitation and response to determine components of complex immittance (i.e., either impedance or admittance) at n+m discrete frequencies, where n is an integer equal to or greater than two and m is an integer equal to or greater than one. Computation circuitry utilizes measured complex immittance components at the n discrete frequencies to evaluate the elements of a 2n-element equivalent circuit model. It then calculates the complex immittance of this model at the m discrete frequencies and mathematically compares components of the calculated immittances with components of the measured immittances at the m discrete frequencies. The results of this comparison are related to the degree of cell deterioration. A pass/fail determination can thus be made based solely upon cell deterioration—without even knowing the battery'"'"'s manufacturer, group size, or its electrical ratings.
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Citations
26 Claims
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1. Apparatus for determining a physical property of an electrochemical cell or battery comprising:
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measuring circuitry adapted to apply time-varying electrical excitation to said cell or battery, to sense time-varying electrical response to said excitation, and to utilize said excitation and said response to determine components of complex immittance at n+m discrete frequencies, where n is an integer equal to or greater than two and m is an integer equal to or greater than one; computation circuitry responsive to said complex immittance components and adapted to evaluate the elements of a 2n-element equivalent circuit model from said complex immittance components at said n discrete frequencies, adapted to calculate the complex immittance components of said model at said m discrete frequencies, and adapted to mathematically compare said calculated components with said measured immittance components at said m discrete frequencies, the results of said comparison being related to said physical property. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for determining a physical property of an electrochemical cell or battery comprising the steps of:
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measuring the complex immittance of said cell or battery at n+m discrete frequencies where n is an integer equal to or greater than two and m is an integer equal to or greater than one; evaluating elements of an equivalent circuit model from said immittance at said n discrete frequencies, said model comprising 2n discrete electrical elements; calculating the complex immittance of said circuit model at said m discrete frequencies; mathematically comparing components of said calculated and measured complex immittances at said m discrete frequencies; and
,determining said physical property from said comparison. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. Apparatus for evaluating the degree of cell deterioration in an electrochemical cell or battery comprising:
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electrical excitation circuitry adapted to apply time-varying electrical excitation to said cell or battery, said excitation containing frequency components at n+m discrete frequencies where n is an integer equal to or greater than two and m is an integer equal to or greater than one; response sensing circuitry configured to sense time-varying electrical response of said cell or battery at said n+m discrete frequencies; computation circuitry responsive to said time-varying excitation and to said time-varying response and adapted to compute the complex immittance of said cell or battery at said n+m discrete frequencies, adapted to evaluate element values of a 2n-element equivalent circuit model of said cell or battery from said n immittance values, adapted to calculate complex immittance components of said model at said m discrete frequencies, and adapted to mathematically compare said calculated components with said measured immittance components at said m discrete frequencies, the results of said comparison being related to said degree of cell deterioration. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A method for determining the degree of cell deterioration of an electrochemical cell or battery comprising the steps of:
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measuring the complex immittance of said cell or battery at n+m discrete frequencies where n is an integer equal to or greater than two and m is an integer equal to or greater than one; evaluating elements of an equivalent circuit model from said n immittance measurements, said model comprising 2n discrete electrical elements; calculating the complex immittance of said circuit model at said m discrete frequencies; mathematically comparing components of said calculated and measured complex immittance at said m discrete frequencies; and
,determining said degree of cell deterioration from said comparison. - View Dependent Claims (23, 24, 25, 26)
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Specification