Charging apparatus and method of secondary battery

Patent metadata

Field	Value
Publication number	US-12237708-B2
Application number	US-202017004118-A
Country	US
Kind code	B2
Filing date	Aug 27, 2020
Priority date	Dec 6, 2018
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A charging apparatus includes a control unit configured to determine an average ion concentration, a surface ion concentration and a solid phase potential for anode particles and an electrolyte potential in an anode, using a predefined electrochemical reduced order model. The control unit is further configured to determine a side reaction rate from the solid phase potential and the electrolyte potential. The control unit is further configured to reduce the magnitude of the charging current applied to a secondary battery based on at least one of a cutoff voltage, the surface ion concentration and the side reaction rate.

First claim

What is claimed is:

1. A charging apparatus of a secondary battery, comprising:
a voltage sensor configured to measure a voltage of the secondary battery;
a temperature sensor configured to measure a temperature of the secondary battery; and
a control unit configured to receive a measured voltage value and a measured temperature value from the voltage sensor and the temperature sensor, respectively, and to adjust a magnitude of a charging current applied to the secondary battery,
wherein the control unit is configured to:
determine an internal state of the secondary battery, which includes an average ion concentration of anode particles, a surface ion concentration of the anode particles, an anode particle potential and an anode electrolyte potential, using a predefined electrochemical reduced order model (ROM);
determine a state of charge (SOC) of the secondary battery from the average ion concentration;
determine a side reaction rate from the anode particle potential and the anode electrolyte potential;
determine whether the measured voltage value reaches a cutoff voltage;
determine whether the surface ion concentration of the anode particles reaches an upper limit concentration;
determine whether the side reaction rate reaches an upper limit rate; and
reduce the magnitude of the charging current applied to the secondary battery from a current charging current amount to an updated charging current amount in response to the measured voltage value reaching the cutoff voltage;
reduce the magnitude of the charging current applied to the secondary battery from the current charging current amount to the updated charging current amount in response to the surface ion concentration of the anode particles reaching the upper limit concentration; and
reduce the magnitude of the charging current applied to the secondary battery from the current charging current amount to the updated charging current amount in response to the side reaction rate reaching the upper limit rate,
wherein the updated charging current amount corresponds to an updated SOC value in a prestored profile correlating charging rate values to SOC values, and wherein the updated SOC value is greater than the determined SOC of the secondary battery by a predetermined amount, wherein the predetermined amount is a constant value regardless of the determined SOC of the secondary battery.

2. The charging apparatus according to claim 1 ,
wherein the electrochemical reduced order model is derived from a full order model defined by an ion conservation equation in an electrode, an ion conservation equation in an electrolyte, a charge conservation equation in the electrode, a charge conservation equation in the electrolyte and an electrochemical kinetics equation, wherein the ion conservation equation in the electrode is represented by:

∂

c
s

∂
t

=

D
s

r
2

⁢

∂

∂
r

⁢

(

r
2

⁢

∂

c
s

∂
r

)

1
2

⁢

∂

c
s

∂
r

⁢

|

r
=
0

=

0
⁢

⁢
and
⁢

⁢

D
s

⁢

∂

c
s

∂
r

⁢

|

r
=

R
s

=

-

j
Li

a
s

⁢
F

wherein C s is an ion concentration in solid phase, D s is a diffusion coefficient in solid phase, R s is a radius of a spherical electrode particle, j Li is a lithium reaction rate, a s is a specific surface area of the electrode, F is a Faraday constant, and r is a spherical coordinate
wherein the ion conservation equation in the electrolyte is represented by:

∂

(

ɛ
e

⁢

c
e

)

∂
f

=

∂

∂
x

⁢

(

D

Assignees

• Lg Chemical Ltd
• Univ Auburn
• Lg Energy Solution Ltd

Inventors

• Choe Song-Yul
• Yin Yilin
• Cho Ha-Na
• Joe Won-Tae
• Ahn Hyoung Jun
• Lim Jin-Hyung

Classifications

• H02J7/971

  the charge cycle being controlled or terminated in response to non-electric parameters · CPC title

• H02J7/96 Primary

  in response to battery voltage · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/977

  of the battery · CPC title

• H02J7/933 Primary

  the cycle being controlled or terminated in response to electric parameters · CPC title