US4881037A
Expired / Lapsed
US
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Apparatus and method for measuring the interfacial impedance in an electrochemical cell
Assignee: Massachusetts Institute of Technology
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Filing: 1989-01-26
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Granted: 1989-11-14
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Expires: 2009-01-26
Abstract
Abstract Apparatus for measuring the interfacial impedance in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium that includes circuitry for measuring the interaction current flowing between the electrodes at a series of predetermined external impedance values and an analyzer for determining the interfacial impedance based on the current measurements.
Inventors
- 👤 James G. Bellingham
- 👤 Margaret L. A. MacVicar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:58
CPC Classifications
G; G01; G01N; G01N17/00; G01N17/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
53 words
Apparatus for measuring the interfacial impedance in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium comprising circuitry for measuring the interaction current flowing between said electrodes at a series of predetermined external impedance values; and an analyzer for determining said interfacial impedance based on said current measurements.
Claim 2
Dependent Claim
53 words
Apparatus for measuring the interfacial impedance in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium comprising circuitry for measuring the interaction current flowing between said electrodes at a series of predetermined external impedance values; and an analyzer for determining said interfacial impedance based on said current measurements.
Claim 3
Dependent Claim
32 words
The apparatus of claim 1 wherein said circuitry for measuring said current comprises an ammeter for detecting said interaction current and a variable impedance element for establishing said predetermined external impedance values.
Claim 4
Dependent Claim
42 words
The apparatus of claim 1 wherein said circuitry for measuring said current comprises a variable impedance element for establishing said predetermined external impedance values and a voltmeter for measuring the voltage drop across said variable impedance element to determine said interaction current.
Claim 5
Dependent Claim
11 words
The apparatus of claim 1 wherein said ammeter comprises a magnetometer.
Claim 6
Dependent Claim
15 words
The apparatus of claim 4 wherein said ammeter comprises a superconducting quantum interference device magnetometer.
Claim 7
Independent Claim
16 words
The apparatus of claims 2 or 3 wherein said variable impedance element comprises a variable resistor.
Claim 8
Dependent Claim
12 words
The apparatus of claim 1 wherein said analyzer comprises a digital computer.
Claim 9
Independent Claim
58 words
A method for measuring the interfacial impedance in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium comprising the steps of determining the intrinsic interaction current flowing between said electrodes as a function of frequency at a series of predetermined external impedance values; and determining said interfacial impedance based on said interaction current.
Claim 10
Independent Claim
58 words
A method for measuring the interfacial impedance in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium comprising the steps of determining the intrinsic interaction current flowing between said electrodes as a function of frequency at a series of predetermined external impedance values; and determining said interfacial impedance based on said interaction current.
Claim 11
Dependent Claim
60 words
The method of claim 8 wherein said interaction current is measured over a set of predetermined time intervals for each of said predetermined external impedance values to obtain said interaction current as a function of time and external impedance, whereupon said time-dependent interaction current values are transformed to yield said interaction current as a function of frequency and external impedance.
Claim 12
Independent Claim
73 words
A method for determining the source of the intrinsic interaction current in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium comprising the steps of determining the intrinsic interaction current flowing between said electrodes as a function of frequency at a series of predetermined external impedance values; and comparing said interaction current function with a set of interaction current functions corresponding to known sources to determine said source.
Claim 13
Independent Claim
73 words
A method for determining the source of the intrinsic interaction current in an electrochemical cell having a pair of electrodes in contact with an electrolyte medium comprising the steps of determining the intrinsic interaction current flowing between said electrodes as a function of frequency at a series of predetermined external impedance values; and comparing said interaction current function with a set of interaction current functions corresponding to known sources to determine said source.
References Cited (Backward Citations)
US3947329A
Cited
US4575678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |