Method for the in-situ recalibration of a comparison electrode incorporated into an electrochemical system

Patent metadata

Field	Value
Publication number	US-2016290959-A1
Application number	US-201415038192-A
Country	US
Kind code	A1
Filing date	Nov 14, 2014
Priority date	Nov 21, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

A method recalibrates in situ a comparison electrode integrated into an electrochemical system. The electrochemical system includes a working electrode, a counter electrode, and an electrolyte. The method includes verifying a potential of the comparison electrode relative to the working electrode or to the counter electrode in situ, detecting whether there is a drift in the potential of the comparison electrode relative to a potential plateau for which the comparison electrode was functionalized or designed, and when the drift is detected, recalibrating the comparison electrode in situ.

First claim

1 - 9 . (canceled)

10 . A method for recalibrating in situ a comparison electrode integrated into an electrochemical system comprising a working electrode, a counter electrode, and an electrolyte, the method comprising:
verifying a potential of the comparison electrode relative to the working electrode or to the counter electrode in situ; detecting whether there is a drift in the potential of the comparison electrode relative to a potential plateau for which the comparison electrode was functionalized or designed; and when the drift is detected, recalibrating the comparison electrode in situ.

11 . The method as claimed in claim 10 , wherein the potential of the comparison electrode relative to the working electrode or to the counter electrode is verified in situ by applying the following steps:
measuring the potential of the comparison electrode; then applying a verification current of positive amplitude for a first duration; then measuring a first variation in the potential of the comparison electrode; then applying a verification current of negative amplitude for a second duration; then measuring a second variation in the potential of the comparison electrode; then determining a voltage measurement depending on the first variation and the second variation in potential.

12 . The method as claimed in claim 11 , wherein a product of the amplitude of the verification currents multiplied by the respective durations is at least equal to one tenth of a maximum charge of the comparison electrode and at most equal to the maximum charge of the comparison electrode.

13 . The method as claimed in claim 11 , wherein the drift in the potential of the comparison electrode is detected when the measured voltage is higher than a plateau voltage increased, for a given temperature, by a shift voltage value of at least equal to 20 mV±5 mV.

14 . The method as claimed in claim 10 , wherein the potential of the comparison electrode is verified and drift in the potential of the comparison electrode detected periodically, depending on a time period that has passed since a last functionalization.

15 . The method as claimed in claim 10 , wherein the potential of the comparison electrode is verified during a period of relaxation of the electrochemical system consecutive to a complete recharge.

16 . The method as claimed in claim 10 , wherein the comparison electrode is recalibrated by carrying out the following steps:
applying a recalibration current of negative amplitude until a first variation in potential; then memorizing a potential value obtained by way of lower bound; then applying a recalibration current of positive amplitude, until a second variation in potential; then memorizing the potential value obtained by way of upper bound; then determining a capacity of the comparison electrode depending on the lower potential bound, on the upper potential bound and on the applied current; then determining a state of ageing of the comparison electrode from its initial capacity and the determined capacity; when the state of ageing is above a threshold, applying a negative current in order to obtain a state of charge; and when the state of ageing is not above the threshold, declaring that the comparison electrode has failed.

17 . The method as claimed in claim 16 , wherein a product of the amplitude of the recalibration currents multiplied by a duration of application of the recalibration currents is higher than one fifth of a total charge of the comparison electrode.

18 . The method as claimed in claim 10 , wherein the comparison electrode is recalibrated by applying in succession a recalibration current of positive amplitude then a recalibration current of negative amplitude in order to reposition the potential of the comparison electrode on the potential plateau.

19 . The method as claimed in claim 18 , wherein a product of the amplitude of the recalibration currents multiplied by a duration of application of the recalibration currents is higher than one fifth of a total charge of the comparison electrode.

Assignees

• Renault Sa

Inventors

• Genies Sylvie
• Alias Melanie
• Leirens Sylvain
• Kirchev Angel Zhivkov

Classifications

• H01M10/48 Primary

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title

• G01N27/4163 Primary

  checking the operation of, or calibrating, the measuring apparatus (G01N27/3274, G01N27/4175 and G01N33/0006 take precedence) · CPC title

• G01N27/301

  Reference electrodes · CPC title

• H01M2010/4271

  Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing · CPC title

• H01M10/052

  Li-accumulators · CPC title