Battery charging method and device, and storage medium
Provided are a battery charging method and device, and a storage medium that are applicable to a lithium-ion battery with an N/P range of 0.5 to 1.1. The method includes: obtaining, by a power management system, a state of health (SOH) loss of the lithium-ion battery; and determining a charge cut-off voltage of a next charge process based on the SOH loss, an initial charge cut-off voltage of the lithium-ion battery, and a voltage correction factor, where the initial charge cut-off voltage is determined based on the N/P, and the charge cut-off voltage increases with increase of a count of charging. The N/P range is 0.5 to 1.1, thereby reducing the dosage of the negative electrode and reducing cost. In addition, the charge cut-off voltage of the next charge process is increased based on the SOH loss, thereby ensuring that the lithium-ion battery is free from lithium plating.
1 . A battery charging method, comprising:
obtaining, by a power management system, an SOH loss of a lithium-ion battery and an initial charge cut-off voltage, wherein the lithium-ion battery comprises a negative electrode and a positive electrode with an N/P range of 0.5 to 1.1, the N/P is a ratio of a capacity per unit area of the negative electrode to a capacity per unit area of the positive electrode, the initial charge cut-off voltage is determined based on a maximum charge capacity per unit mass of a positive electrode material of the positive electrode, a differential voltage vs. capacity curve of the positive electrode material, a safety redundancy factor, a lower-limit cut-off voltage applied to the lithium-ion battery, and the N/P;
determining, by the power management system, a charge cut-off voltage of a next charge process of the lithium-ion battery based on the SOH loss, the initial charge cut-off voltage of the lithium-ion battery, and a voltage correction factor, wherein the initial charge cut-off voltage is determined based on the N/P, and the charge cut-off voltage increases with increase of a count of charging; and
performing, by the power management system, the next charge process to charge the lithium-ion battery until the charge cut-off voltage is reached.
2 . The method according to claim 1 , wherein the N/P range is 0.8 to 1.0.
3 . The method according to claim 1 , wherein the charge cut-off voltage of the next charge process is determined based on the following formula:
U=U 0 +ε×ΔSOH
wherein, U represents the charge cut-off voltage of the next charge process, U 0 represents the initial charge cut-off voltage, ΔSOH represents the SOH loss, and ε represents the voltage correction factor.
4 . The method according to claim 1 ,
wherein the voltage correction factor is determined based on the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery, the differential voltage vs. capacity curve of the positive electrode material, a voltage compensation factor, and an initial coulombic efficiency of the lithium-ion battery.
5 . The method according to claim 4 , wherein the initial charge cut-off voltage is determined based on the following formula:
U
0
=
∫
0
C
0
×
(
N
/
P
)
a
d
U
d
Q
×
d
Q
+
U
l
o
w
wherein, U 0 represents the initial charge cut-off voltage, C 0 represents the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery,
dU
d
Q
represents the differential voltage vs. capacity curve of the positive electrode material, a represents the safety redundancy factor, and U low represents the lower-limit cut-off voltage applied to the lithium-ion battery.
6 . The method according to claim 4 , wherein the voltage correction factor is determined based on the following formula:
ℰ
=
b
×
d
U
C
0
×
d
Q
×
ICE
wherein, ε represents the voltage correction factor, C 0 represents the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery,
dU
d
Q
represents the differential voltage vs. capacity curve of the positive electrode material, b represents the voltage compensation factor, and ICE represents the initial coulombic efficiency of the lithium-ion battery.
7 . The method according to claim 4 , wherein the safety redundancy factor is greater than or equal to 1, and the safety redundancy factor is less than or equal to 1.3.
8 . A battery charging device, comprising:
an obtaining module, configured to obtain an SOH loss of a lithium-ion battery and an initial charge cut-off voltage, wherein the lithium-ion battery comprises a negative electrode and a positive electrode with an N/P range of 0.5 to 1.1, the N/P is a ratio of a capacity per unit area of the negative electrode to a capacity per unit area of the positive electrode, the initial charge cut-off voltage is determined based on a maximum charge capacity per unit mass of a positive electrode material of the positive electrode, a differential voltage vs. capacity curve of the positive electrode material, a safety redundancy factor, a lower-limit cut-off voltage applied to the lithium-ion battery, and the N/P; and
a processing module, configured to:
determine a charge cut-off voltage of a next charge process of the lithium-ion battery based on the SOH loss, the initial charge cut-off voltage of the lithium-ion battery, and a voltage correction factor, wherein the initial charge cut-off voltage is determined based on the N/P, and the charge cut-off voltage increases with increase of a count of charging; and
perform the next charge process to charge the lithium-ion battery until the charge cut-off voltage is reached.
9 . The battery charging device according to claim 8 , wherein the N/P range of the lithium-ion battery is 0.8 to 1.0.
10 . The battery charging device according to claim 8 , wherein the charge cut-off voltage of the next charge process is determined based on the following formula:
U=U 0 +ε×ΔSOH
wherein, U represents the charge cut-off voltage of the next charge process, U 0 represents the initial charge cut-off voltage, ΔSOH represents the SOH loss, and ε represents the voltage correction factor.
11 . The battery charging device according to claim 8 , wherein the voltage correction factor is determined based on the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery, the differential voltage vs. capacity curve of the positive electrode material, a voltage compensation factor, and an initial coulombic efficiency of the lithium-ion battery.
12 . The battery charging device according to claim 11 , wherein the initial charge cut-off voltage is determined based on the following formula:
U
0
=
∫
0
C
0
×
(
N
/
P
)
a
dU
d
Q
×
d
Q
+
U
l
o
w
wherein, U 0 represents the initial charge cut-off voltage, C 0 represents the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery,
dU
d
Q
represents the differential voltage vs. capacity curve of the positive electrode material, a represents the safety redundancy factor, and U low represents the lower-limit cut-off voltage applied to the lithium-ion battery.
13 . The battery charging device according to claim 12 , wherein the voltage correction factor is determined based on the following formula:
ℰ
=
b
×
d
U
C
0
×
d
Q
×
ICE
wherein, ε represents the voltage correction factor, C 0 represents the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery,
dU
d
Q
represents the differential voltage vs. capacity curve of the positive electrode material, b represents the voltage compensation factor, and ICE represents the initial coulombic efficiency of the lithium-ion battery.
14 . The battery charging device according to claim 8 , wherein the safety redundancy factor is greater than or equal to 1, and the safety redundancy factor is less than or equal to 1.3.
15 . An electronic device, comprising:
a processing component; and
a non-volatile computer-readable storage medium storing a computer program that, when executed on the processing component, causes the electronic device to:
obtain an SOH loss of the lithium-ion battery and an initial charge cut-off voltage, wherein lithium-ion battery comprises a negative electrode and a positive electrode with an N/P range of 0.5 to 1.1, the N/P is a ratio of a capacity per unit area of the negative electrode to a capacity per unit area of the positive electrode, the initial charge cut-off voltage is determined based on a maximum charge capacity per unit mass of a positive electrode material of the positive electrode, a differential voltage vs. capacity curve of the positive electrode material, a safety redundancy factor, a lower-limit cut-off voltage applied to the lithium-ion battery, and the N/P;
determine a charge cut-off voltage of a next charge process of the lithium-ion battery based on the SOH loss, the initial charge cut-off voltage of the lithium-ion battery, and a voltage correction factor, wherein the initial charge cut-off voltage is determined based on the N/P, and the charge cut-off voltage increases with increase of a count of charging; and
perform the next charge process to charge the lithium-ion battery until the charge cut-off voltage is reached.
16 . The electronic device according to claim 15 , wherein the N/P range is 0.8 to 1.0.
17 . The electronic device according to claim 15 , wherein the charge cut-off voltage of the next charge process is determined based on the following formula:
U=U 0 +ε×ΔSOH
wherein, U represents the charge cut-off voltage of the next charge process, U 0 represents the initial charge cut-off voltage, ΔSOH represents the SOH loss, and ε represents the voltage correction factor.
18 . The electronic device according to claim 15 , wherein the voltage correction factor is determined based on the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery, the differential voltage vs. capacity curve of the positive electrode material, a voltage compensation factor, and an initial coulombic efficiency of the lithium-ion battery.
19 . The electronic device according to claim 17 , wherein the initial charge cut-off voltage is determined based on the following formula:
U
0
=
∫
0
C
0
×
(
N
/
P
)
a
d
U
d
Q
×
d
Q
+
U
l
o
w
wherein, U 0 represents the initial charge cut-off voltage, C 0 represents the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery,
dU
d
Q
represents the differential voltage vs. capacity curve of the positive electrode material, a represents the safety redundancy factor, and U low represents the lower-limit cut-off voltage applied to the lithium-ion battery.
20 . The electronic device according to claim 15 , wherein the voltage correction factor is determined based on the following formula:
ℰ
=
b
×
d
U
C
0
×
d
Q
×
ICE
wherein, ε represents the voltage correction factor, C 0 represents the maximum charge capacity per unit mass of the positive electrode material of the lithium-ion battery,
dU
d
Q
represents the differential voltage vs. capacity curve of the positive electrode material, b represents the voltage compensation factor, and ICE represents the initial coulombic efficiency of the lithium-ion battery.
21 . The electronic device according to claim 15 , wherein the safety redundancy factor is greater than or equal to 1, and the safety redundancy factor is less than or equal to 1.3.