Charging method, electronic apparatus, and storage medium

1. A method of charging a battery, comprising:

in an m th charge and discharge cycle, constant-current charging a battery to a first cut-off voltage U m at a charging current, wherein m is any two or more integers of 1, 2, 3, . . . , x, and U m has different values in at least two charge and discharge cycles;

wherein U m =U c1 +b, 0<b≤0.5; U c1 is a second cut-off voltage, U c1 is a cut-off voltage of the battery or another battery same as the battery when a constant-current charging stage in an n th charge and discharge cycle ends, or U c1 is a charging limit voltage of the battery or the another battery or a preset value; n is an integer greater than or equal to 0, m is greater than n, and b has different values in at least two charge and discharge cycles.

2. The method according to claim 1 , wherein b=b 1 ×m+b 2 , wherein 0≤b 1 ≤0.0005, and 0≤b 2 ≤0.1.

3. The method according to claim 1 , wherein the first cut-off voltage U m is obtained in the following manner:

selecting a larger one of the second cut-off voltage U c1 and a third cut-off voltage U as the first cut-off voltage U m , wherein the third cut-off voltage satisfies that U=OCV 1 +(U c1 −OCV 1 )×k, OCV 1 is an open-circuit voltage of the battery or another battery when a constant-current charging stage in an n th charge and discharge cycle ends, and k is an impedance growth rate of the battery or the another battery.

4. The method according to claim 3 , wherein the open-circuit voltage OCV 1 and the second cut-off voltage U c1 are obtained through the following steps:

obtaining a correspondence between an open-circuit voltage and a state of charge of the battery and a correspondence between a voltage and a state of charge of the battery; and

based on the correspondence between the open-circuit voltage and the state of charge of the battery and the correspondence between the voltage and the state of charge of the battery, obtaining the open-circuit voltage OCV 1 and the second cut-off voltage U c1 of the battery when the constant-current charging stage in the n th charge and discharge cycle ends.

5. The method according to claim 3 , wherein the impedance growth rate k is obtained through the following steps:

obtaining first battery impedance R 1 of the battery in the n th charge and discharge cycle; and

obtaining second battery impedance R 2 of the battery in an (m−1) th charge and discharge cycle, wherein k=R 2 /R 1 .

6. The method according to claim 1 , further comprising:

comparing magnitude of a first state of charge SOC 1 and that of a second state of charge SOC 2 ;

wherein the SOC 1 is a state of charge of the battery when a constant-current charging stage in an n th charge and discharge cycle ends, and the SOC 2 is a state of charge of the battery before the m th charge and discharge cycle.

7. The method according to claim 6 , further comprising:

in the m th charge and discharge cycle, when the second state of charge SOC 2 is greater than or equal to the first state of charge SOC 1 , constant-voltage charging the battery based on the first cut-off voltage U m and a first charging capacity Q 1 , wherein Q 1 =(1−SOC 2 )×Q, and Q represents a current actual capacity of the battery.

8. The method according to claim 6 , further comprising:

in the m th charge and discharge cycle, when the second state of charge SOC 2 is greater than or equal to the first state of charge SOC 1 , obtaining a fourth cut-off voltage of the battery in a constant-voltage charging stage in an (m−1) th charge and discharge cycle; and

constant-voltage charging the battery based on the fourth cut-off voltage and a first charging capacity Q 1 , wherein Q 1 =(1−SOC 2 )×Q, and Q is a current actual capacity of the battery.

9. The method according to claim 6 , further comprising:

in the m th charge and discharge cycle, when the second state of charge SOC 2 is less than the first state of charge SOC 1 , constant-current charging the battery to the first cut-off voltage U m at the charging current, wherein the charging current is a charging current of the battery or another battery same as the battery in the constant-current charging stage in the n th charge and discharge cycle, or the charging current is a preset value; and

constant-voltage charging the battery to a fully charged state at the first cut-off voltage U m , wherein

a total charging capacity of the battery reaching the fully charged state is a second charging capacity Q 2 , wherein Q 2 =(1−SOC 2 )×Q, and Q is a current actual capacity of the battery.

10. An electronic apparatus, comprising:

a battery; and

a processor configured to perform the method of charging a battery, the method comprising:

in an m th charge and discharge cycle, constant-current charging a battery to a first cut-off voltage U m at a charging current, wherein m is any two or more integers of 1, 2, 3, . . . , x, and U m has different values in at least two charge and discharge cycles;

wherein U m =U c1 +b, 0<b≤0.5; U c1 is a second cut-off voltage, U c1 is a cut-off voltage of the battery or another battery same as the battery when a constant-current charging stage in an n th charge and discharge cycle ends, or U c1 is a charging limit voltage of the battery or the another battery or a preset value; n is an integer greater than or equal to 0, m is greater than n, and b has different values in at least two charge and discharge cycles.

11. The electronic apparatus according to claim 10 , wherein b=b 1 ×m+b 2 , wherein 0≤b 1 ≤0.0005, and 0≤b 2 ≤0.1.

12. The electronic apparatus according to claim 10 , wherein the first cut-off voltage U m is obtained in the following manner:

selecting a larger one of the second cut-off voltage U c1 and a third cut-off voltage U as the first cut-off voltage U m , wherein the third cut-off voltage satisfies that U=OCV 1 +(U c1 −OCV 1 )×k, OCV 1 is an open-circuit voltage of the battery or another battery when a constant-current charging stage in an n th charge and discharge cycle ends, and k is an impedance growth rate of the battery or the another battery.

13. The electronic apparatus according to claim 12 , wherein the open-circuit voltage OCV 1 and the second cut-off voltage U c1 are obtained through the following steps:

obtaining a correspondence between an open-circuit voltage and a state of charge of the battery and a correspondence between a voltage and a state of charge of the battery; and

based on the correspondence between the open-circuit voltage and the state of charge of the battery and the correspondence between the voltage and the state of charge of the battery, obtaining the open-circuit voltage OCV 1 and the second cut-off voltage U c1 of the battery when the constant-current charging stage in the n th charge and discharge cycle ends.

14. The electronic apparatus according to claim 12 , wherein the impedance growth rate k is obtained through the following steps:

obtaining first battery impedance R 1 of the battery in the n th charge and discharge cycle; and

obtaining second battery impedance R 2 of the battery in an (m−1) th charge and discharge cycle, wherein k=R 2 /R 1 .

15. The electronic apparatus according to claim 10 , further comprising:

comparing magnitude of a first state of charge SOC 1 and that of a second state of charge SOC 2 ;

wherein the SOC 1 is a state of charge of the battery when a constant-current charging stage in an n th charge and discharge cycle ends, and the SOC 2 is a state of charge of the battery before the m th charge and discharge cycle.

16. The electronic apparatus according to claim 15 , further comprising:

in the m th charge and discharge cycle, when the second state of charge SOC 2 is greater than or equal to the first state of charge SOC 1 , constant-voltage charging the battery based on the first cut-off voltage U m and a first charging capacity Q 1 , wherein Q 1 =(1−SOC 2 )×Q, and Q is a current actual capacity of the battery.

17. The electronic apparatus according to claim 15 , further comprising:

in the m th charge and discharge cycle, when the second state of charge SOC 2 is greater than or equal to the first state of charge SOC 1 , obtaining a fourth cut-off voltage of the battery in a constant-voltage charging stage in an (m−1) th charge and discharge cycle; and

constant-voltage charging the battery based on the fourth cut-off voltage and a first charging capacity Q 1 , wherein Q 1 =(1−SOC 2 )×Q, and Q represents a current actual capacity of the battery.

18. A non-transitory storage medium, storing at least one computer instruction, wherein the instruction is loaded by a processor and is used to perform the method of charging a battery, the method comprising:

in an m th charge and discharge cycle, constant-current charging a battery to a first cut-off voltage U m at a charging current, wherein m is any two or more integers of 1, 2, 3, . . . , x, and U m has different values in at least two charge and discharge cycles;

wherein U m =U c1 +b, 0<b≤0.5; U c1 is a second cut-off voltage, U c1 is a cut-off voltage of the battery or another battery same as the battery when a constant-current charging stage in an n th charge and discharge cycle ends, or U c1 is a charging limit voltage of the battery or the another battery or a preset value; n is an integer greater than or equal to 0, m is greater than n, and b has different values in at least two charge and discharge cycles.