Method and device for measuring, in real time and in situ, thermodynamic data of a battery (enthalpy and entropy)

Patent metadata

Field	Value
Publication number	US-12123915-B2
Application number	US-201917280011-A
Country	US
Kind code	B2
Filing date	Sep 26, 2019
Priority date	Sep 27, 2018
Publication date	Oct 22, 2024
Grant date	Oct 22, 2024

Abstract

The invention relates to a method and a device for measuring, in real time and in situ, thermodynamic data of a battery (enthalpy and entropy). The object of the invention is to provide a reliable method for measuring, in situ, online and in real time, the variation in entropy (ΔS) of a battery. To this end, the method is characterized in that it consists primarily in: (phase I) producing a prior model of the battery: (a) charging the battery; (b) and/or discharging the battery; (c) measuring actual variables; (d) modeling the electrical behavior of the battery during charging (a) and/or discharging (b) in order to estimate the electrical parameters of the battery; (e) estimating electrical parameters of the battery; (f) modeling the thermal behavior of the battery during charging (a) and/or discharging (b) in order to estimate ΔS in situ, online and in real time; (g) estimating ΔS, by using at least one of the electrical parameters estimated in step (d); (phase II) measuring ΔS of the battery during use in any application and with any state of charge by carrying out step (d) and step (f) of phase I, step (c) and step (g); (phase III) optionally storing the data measured/calculated in phase II and/or in phase I. The invention also relates to a method for determining the state of charge and the state of health of a battery on the basis of these thermodynamic data. Another subject of the invention is a device for implementing this method.

First claim

The invention claimed is:

1. A method for measuring, in situ, online and in real time, thermodynamic data including a variation in entropy ΔS, of at least one battery, the method comprising:
a modelling phase: producing a prior model of the battery of which a state of charge (SOC) is comprised between 0 and 100% by implementing:
step (a) charging the battery at least partially with a charge current signal Sc, wherein the step (a) is optionally followed by a step (b) discharging the battery at least partially with a discharge current signal Sd;
step (c) measuring actual variables useful in the following steps;
step (d)modelling electrical behaviour of the battery during the charging step (a) with the charge current signal Sc and/or the discharging step (b) with the discharge current signal Sd, in order to estimate electrical parameters of the battery;
step (e) estimating periodically, at a first alternating current frequency Fe, the electrical parameters of the battery;
step (f) modelling thermal behaviour of the battery during charging in the step (a) with the charge current signal Sc and/or discharging in the step (b) with the discharge current signal Sd, in order to estimate in situ, online and in real time, at least one of parameters of a thermal model, namely ΔS;
step (g)estimating periodically, at a second alternating current frequency Fg, the at least one of the parameters of the thermal model ΔS, by using at least one of the electrical parameters estimated in the step (e); and

an estimating phase:
estimating thermodynamic data including ΔS of the battery during use in an application and with any state of charge, by implementing an electrical model in the step (d) and the thermal model in the step (f) of the modelling phase,
estimating electrical parameters in the step (e), and
estimating at least one of the parameters of the thermal model ΔS in the step (g),
wherein
the modelling in the step (d) consists in considering that the battery is an electrical circuit or the electrical model comprising a resistor R 0 , an open circuit voltage OCV, and a circuit R 1 C 1 in series, the electrical behaviour of the battery being described, in this electrical model, by the following equations:

{

U
.

1

=

-

1

C
1

⁢

R
1

⁢

U
1

+

1

C
1

⁢
I
⁢

⁢

(
1
)

V
bat

=

OCV
+

U
1

+

R
0

⁢

⁢
I
⁢

⁢

(
2
)

where U 1 is a voltage at terminals of the circuit R 1 C 1 , I is a current passing through the battery and V bat a voltage at terminals of the battery, the equation (2) being discretised as follows:
V bat,k =I k b 0,k +I k-1 b 1,k +a 1,k ( OCV k-1 −V bat,k-1 )+ OCV k   (2′)

and thus rewritten:

V

bat
,
k

=

Θ
k
T

⁢

Φ
k

⁢

⁢

with
:

⁢

{

Θ
k
T

=

[

b

0
,
k

Assignees

• Inst Polytechnique Grenoble

Inventors

• El Outmani Sohaib
• Sename Olivier
• Granjon Pierre
• Yazami Rachid

Classifications

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• H01M10/48

  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

• G01R31/367

  Software therefor, e.g. for battery testing using modelling or look-up tables · CPC title