US 2014/0372054 A1 · DOUBLE-PULSE TECHNIQUE FOR ON-LINE DIAGNOSTICS OF ELECTROCHEMICAL SYSTEMS

Abstract

A method for dynamic characterization of an electrochemical system (such as a lithium-ion battery) is provided, comprising exciting an electrochemical system with a plurality of double-pulse sequences, each comprising a constant-current discharge pulse, a constant-current charge pulse having the same pulse width and pulse amplitude, and a zero-current period between the pulses; and calculating an impulse response, using a recursive or matrix-based method, to dynamically characterize the electrochemical system. A constant state-of-charge is maintained in the electrochemical system. Therefore the signal-to-noise ratio is high due to the repetition of the driving sequence. This method may be employed for on-line determination of the impedance spectrum of an electrochemical system, since the cycling profile can be easily integrated into charge/discharge profiles. Batteries (and other devices) can be diagnosed at high speed and with high accuracy. The double-pulse sequence is robust for fairly noisy systems.

Claims24

Dependent claims

A method for dynamic characterization of an electrochemical system, said method comprising:

(a) selecting an electrochemical system to be characterized at a plurality of times within a selected sampling window;
(b) exciting said system with a plurality of double-pulse sequences, wherein each of said double-pulse sequences comprises a discharge pulse having a pulse width and a pulse amplitude, a charge pulse having said pulse width and said pulse amplitude, and a zero-current period;
(c) receiving current data inputs each comprising measured current at a plurality of times associated with said double-pulse sequences;
(d) receiving voltage data inputs each comprising measured voltage at a plurality of times associated with said double-pulse sequences;
(e) calculating a plurality of current-derivative data inputs each comprising the time derivative of said measured current at said plurality of times;
(f) calculating a plurality of voltage-derivative data inputs each comprising the time derivative of said measured voltage at said plurality of times;
and
(g) calculating an impulse response from said current, voltage, current-derivative, and voltage-derivative data inputs, at said plurality of times using a recursive or matrix-based technique, wherein said impulse response dynamically characterizes said electrochemical system.

5 more elements

A system for dynamically characterizing an electrochemical device, said system comprising an electrochemical device and a programmable power-supply apparatus electrically linked with said electrochemical device, wherein said programmable power-supply apparatus is programmed using non-transitory memory with executable code for executing the steps of:

(a) exciting said electrochemical system with a plurality of double-pulse sequences, wherein each of said double-pulse sequences comprises a discharge pulse having a pulse width and a pulse amplitude, a charge pulse having said pulse width and said pulse amplitude, and a zero-current period;
(b) sensing, in said computer, current data inputs each comprising measured current at a plurality of times associated with said double-pulse sequences;
(c) sensing, in said computer, voltage data inputs each comprising measured voltage at a plurality of times associated with said double-pulse sequences;
(d) calculating, in said computer, a plurality of current-derivative data inputs each comprising the time derivative of said measured current at said plurality of times;
(e) calculating, in said computer, a plurality of voltage-derivative data inputs each comprising the time derivative of said measured voltage at said plurality of times;
and
(f) calculating an impulse response from said current, voltage, current-derivative, and voltage-derivative data inputs, at said plurality of times using a recursive or matrix-based method performed in said computer, wherein said impulse response characterizes the dynamics of said electrochemical system.

4 more elements

A computer-readable medium containing program instructions for characterizing the dynamics of an electrochemical system, wherein execution of said program instructions by one or more processors of a computer causes said one or more processors to carry out the steps of:

(a) exciting said electrochemical system with a plurality of double-pulse sequences, wherein each of said double-pulse sequences comprises a discharge pulse having a pulse width and a pulse amplitude, a charge pulse having said pulse width and said pulse amplitude, and a zero-current period;
(b) sensing, in said computer, current data inputs each comprising measured current at a plurality of times associated with said double-pulse sequences;
(c) sensing, in said computer, voltage data inputs each comprising measured voltage at a plurality of times associated with said double-pulse sequences;
(d) calculating, in said computer, a plurality of current-derivative data inputs each comprising the time derivative of said measured current at said plurality of times;
(e) calculating, in said computer, a plurality of voltage-derivative data inputs each comprising the time derivative of said measured voltage at said plurality of times;
and
(f) calculating an impulse response from said current, voltage, current-derivative, and voltage-derivative data inputs, at said plurality of times using a recursive or matrix-based method performed in said computer, wherein said impulse response characterizes the dynamics of said electrochemical system.

4 more elements

Dependencies are inferred from the claim text.

Double-pulse technique for on-line diagnostics of electrochemical systems

Life of this patent

Double-pulse technique for on-line diagnostics of electrochemical systems

Life of this patent

Abstract

Claims24