Method and apparatus for correcting state of health of battery, management system, and storage medium
This disclosure provides a method and an apparatus for correcting a state of health of a battery, a battery management system, and a storage medium, and relates to the field of battery technologies. The method includes: determining whether a current voltage value of a battery cell is within a correction OCV section of the battery cell; if yes, using the current voltage value of the battery cell as a correction voltage value; and acquiring an SOC correction value, and correcting a state of health (SOH) of the battery cell. According to the method, the apparatus, the battery management system, and the storage medium in this disclosure, reliability of an SOH correction result is improved, thereby providing accurate estimation of the state of health of the battery, a prolonged service life of the battery, and better user experience.
1. A method for correcting a state of health (SOH) of a battery cell, performed at an apparatus that is communicatively connected to the battery cell and including a processor and memory, the method comprising:
establishing a connection between the apparatus and the battery cell through a communications interface of the apparatus;
acquiring, via the connection between the apparatus and the battery cell, a first current voltage value V0 of a battery cell;
when V0 is within a correction open-circuit voltage (OCV) section of the battery cell, acquiring, via the connection between the apparatus and the battery cell, a first state of charge (SOC) SOC0 and a first cumulative charge and discharge capacity Q0 corresponding to V0, wherein the correction OCV section comprises at least one of a non-attenuation OCV section and a non-hysteresis OCV section, an OCV of the battery cell is unaffected by battery aging in the non-attenuation OCV section, and an OCV of the battery cell is unaffected by a hysteresis effect in the non-hysteresis OCV section;
acquiring, via the connection between the apparatus and the battery cell, a second current voltage value V1 of the battery cell;
when V1 is within the correction OCV section of the battery cell, acquiring, via the connection between the apparatus and the battery cell, a second state of charge SOC1 and a second cumulative charge and discharge capacity Q1 corresponding to V1;
acquiring, via the connection between the apparatus and the battery cell, a current SOH correction value of the battery cell based on a ratio of a variation between Q0 and Q1 to a variation between SOC0 and SOC1; and
updating a SOH output value of the battery cell by using the current SOH correction value of the battery cell.
2. The method according to claim 1 , wherein the acquiring a current SOH correction value of the battery cell based on a ratio of a variation between Q0 and Q1 to a variation between SOC0 and SOC1 comprises:
acquiring an actual capacity of the battery cell based on the ratio of the variation between Q0 and Q1 to the variation between SOC0 and SOC1; and
acquiring the current SOH correction value of the battery cell based on the actual capacity of the battery cell and a nominal capacity of the battery cell.
3. The method according to claim 1 , wherein the acquiring a first current voltage value V0 of a battery cell comprises:
acquiring the first current voltage value V0 of the battery cell when a battery standing condition is satisfied; and
the acquiring a second current voltage value V1 of the battery cell comprises:
acquiring the second current voltage value V1 of the battery cell when the battery standing condition is satisfied.
4. The method according to claim 3 , wherein the battery standing condition comprises at least one of: a duration in which an external circuit of the battery cell has no current or a current in the external circuit of the battery cell is less than a current threshold exceeds a preset time threshold, and a voltage change rate of the battery cell is less than a preset rate change threshold.
5. The method according to claim 1 , wherein the updating a SOH output value of the battery cell by using the current SOH correction value of the battery cell comprises:
updating the SOH output value of the battery cell by using the current SOH correction value of the battery cell when the current SOH correction value of the battery cell is less than a previous SOH correction value of the battery cell.
6. The method according to claim 5 , wherein the updating an SOH output value of the battery cell by using the current SOH correction value of the battery cell comprises:
updating the SOH output value of the battery cell by using the current SOH correction value of the battery cell according to an update rule, wherein
the update rule comprises: a variation between the current SOH correction value of the battery cell and the previous SOH correction value of the battery cell is not greater than a maximum SOH update value for a single update.
7. The method according to claim 1 , wherein when the second current voltage value V1 is a full-charge voltage value of the battery cell, the acquiring a second state of charge SOC1 and a second cumulative charge and discharge capacity Q1 that are corresponding to V1 comprises:
acquiring a full-charge SOC1 of the battery cell and a full-charge cumulative charge and discharge capacity Q1 of the battery cell.
8. An apparatus for correcting a state of health (SOH) of a battery, the apparatus comprising:
a memory;
a processor;
a communications interface; and
a plurality of instructions stored in the memory that, when executed by the processor, cause the apparatus to:
establish a connection between the apparatus and the battery cell through the communications interface of the apparatus;
acquire, via the connection between the apparatus and the battery cell, a first current voltage value V0 of a battery cell;
when V0 is within a correction open-circuit voltage (OCV) section of the battery cell, acquire, via the connection between the apparatus and the battery cell, a first state of charge (SOC) SOC0 and a first cumulative charge and discharge capacity Q0 corresponding to V0, wherein the correction OCV section comprises at least one of a non-attenuation OCV section and a non-hysteresis OCV section, an OCV of the battery cell is unaffected by battery aging in the non-attenuation OCV section, and an OCV of the battery cell is unaffected by a hysteresis effect in the non-hysteresis OCV section;
acquire, via the connection between the apparatus and the battery cell, a second current voltage value V1 of the battery cell;
when V1 is within the correction OCV section of the battery cell, acquire, via the connection between the apparatus and the battery cell, a second state of charge SOC1 and a second cumulative charge and discharge capacity Q1 corresponding to V1;
acquire, via the connection between the apparatus and the battery cell, a current SOH correction value of the battery cell based on a ratio of a variation between Q0 and Q1 to a variation between SOC0 and SOC1; and
update a SOH output value of the battery cell by using the current SOH correction value of the battery cell.
9. The apparatus according to claim 8 , wherein the apparatus is configured to:
acquire an actual capacity of the battery cell based on the ratio of the variation between Q0 and Q1 to the variation between SOC0 and SOC1; and
acquire the current SOH correction value of the battery cell based on the actual capacity of the battery cell and a nominal capacity of the battery cell.
10. The apparatus according to claim 8 , wherein the apparatus is configured to:
determine whether a battery standing condition is satisfied; and
when the battery standing condition is satisfied, determine whether the first current voltage value V0 of the battery cell and the second current voltage value V1 of the battery cell are within the correction OCV section of the battery cell.
11. The apparatus according to claim 10 , wherein the battery standing condition comprises at least one of: duration in which an external circuit of the battery cell has no current or a current in the external circuit of the battery cell is less than a current threshold exceeds a preset time threshold, and a voltage change rate of the battery cell is less than a preset rate change threshold.
12. The apparatus according to claim 8 , wherein the apparatus is configured to:
update the SOH output value of the battery cell by using the current SOH correction value of the battery cell when the current SOH correction value of the battery cell is less than a previous SOH correction value of the battery cell.
13. The apparatus according to claim 12 , wherein the apparatus is configured to:
update the SOH output value of the battery cell by using the current SOH correction value of the battery cell according to an update rule, wherein
the update rule comprises: a variation between the current SOH correction value of the battery cell and the previous SOH correction value of the battery cell is not greater than a maximum SOH update value for a single update.
14. The apparatus according to claim 8 , wherein the apparatus is configured to:
when the second current voltage value V1 is a full-charge voltage value of the battery cell, acquire a full-charge SOC1 of the battery cell and a full-charge cumulative charge and discharge capacity Q1 of the battery cell.