Apparatus and method for acquiring degradation information of lithium-ion battery cell

Patent metadata

Field	Value
Publication number	US-11187756-B2
Application number	US-201816487270-A
Country	US
Kind code	B2
Filing date	Sep 6, 2018
Priority date	Sep 28, 2017
Publication date	Nov 30, 2021
Grant date	Nov 30, 2021

Abstract

Provided are an apparatus and method of obtaining degradation information of a lithium ion battery cell. The apparatus according to an embodiment estimates a first positive electrode usage region related to a first state of health of the lithium ion battery cell. The apparatus estimates a second positive electrode usage region related to a second state of health of the lithium ion battery cell. Then, the apparatus calculates an amount of change of maximum storage capacity of a positive electrode of the lithium ion battery cell with respect to a usage period from the first state of health to the second state of health, based on the first positive electrode usage region and the second positive electrode usage region.

First claim

What is claimed is:

1. An apparatus for obtaining degradation information of a lithium ion battery cell, the apparatus comprising:
a sensing unit configured to measure:
a full-cell open circuit voltage; and
a current of the lithium ion battery cell; and

a controller operably coupled to the sensing unit, the controller being configured to:
estimate a first positive electrode usage region of the lithium ion battery cell, based on a full-cell open circuit voltage and a current measured by the sensing unit while the lithium ion battery cell is in a first state of health, the first positive electrode usage region being a first range of values;
estimate a second positive electrode usage region of the lithium ion battery cell, based on an open circuit voltage and a current measured by the sensing unit while the lithium ion battery cell is in a second state of health that is degraded as compared to the first state of health, the second positive electrode usage region being a second range of values; and
calculate an amount of change of maximum storage capacity of a positive electrode of the lithium ion battery cell with respect to an usage period from the first state of health to the second state of health, based on the first positive electrode usage region and the second positive electrode usage region,

wherein the first positive electrode usage region is defined by a first positive electrode upper limit value and a first positive electrode lower limit value,
wherein the second positive electrode usage region is defined by:
a second positive electrode upper limit value, and
a second positive electrode lower limit value,

wherein the first positive electrode upper limit value corresponds to an amount of lithium ions stored in the positive electrode of the lithium ion battery cell when a state of charge of the lithium ion battery cell in the first state of health is at a pre-determined upper limit value,
wherein the first positive electrode lower limit value corresponds to an amount of lithium ions stored in the positive electrode of the lithium ion battery cell when the state of charge of the lithium ion battery cell in the first state of health is at a pre-determined lower limit value,
wherein the second positive electrode upper limit value corresponds to an amount of lithium ions stored in the positive electrode of the lithium ion battery cell when the state of charge of the lithium ion battery cell in the second state of health is at the pre-determined upper limit value,
wherein the second positive electrode lower limit value corresponds to an amount of lithium ions stored in the positive electrode of the lithium ion battery cell when the state of charge of the lithium ion battery cell in the second state of health is at the pre-determined lower limit value,
wherein the controller is further configured to calculate the amount of change of the maximum storage capacity of the positive electrode of the lithium ion battery cell with respect to the usage period by using an equation below:

Δ
⁢

⁢

Q
P
t

=

Q

P

_
⁢

⁢
SOH
⁢

⁢
1

t

-

Q

P

_
⁢

⁢
SOH
⁢

⁢
2

t

=

Q

F
⁢

⁢
_
⁢

⁢
SOH
⁢

⁢
1

t

p

f
⁢

⁢
_
⁢

⁢
SOH
⁢

⁢
1

-

p

i
⁢

⁢
_
⁢

⁢
SOH
⁢

⁢
1

-

Q

F
⁢

⁢
_
⁢

⁢
SOH
⁢

⁢
2

t

p

Assignees

• Lg Chemical Ltd

Inventors

• Lim Jin-Hyung
• Yoon Du-Seong
• Joe Won-Tae

Classifications

• G01R31/3842

  combining voltage and current measurements · CPC title

• G01R31/36

  Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] · CPC title

• G01R31/396

  Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery · CPC title

• G01R31/3648

  comprising digital calculation means, e.g. for performing an algorithm · CPC title

• G01R31/382

  Arrangements for monitoring battery or accumulator variables, e.g. SoC · CPC title