Method, apparatus and system for controlling charging of battery module

1. A method for controlling charging of a battery module, comprising:

acquiring an internal pressure value of the battery module;

determining a target pressure threshold range to which the acquired internal pressure value of the battery module belongs, based on a plurality of predefined pressure threshold ranges;

obtaining a target charge cutoff voltage corresponding to the target pressure threshold range, based on a correspondence relationship between a plurality of predefined charge cutoff voltages and the plurality of predefined pressure threshold ranges, wherein the target charge cutoff voltage is a target upper limit voltage for charging the battery module when the acquired internal pressure value of the battery module is within the target pressure threshold range; and

controlling the battery module to be charged based on the obtained target charge cutoff voltage, wherein:

a first pressure threshold range and a second pressure threshold range are any two adjacent pressure threshold ranges selected from the plurality of predefined pressure threshold ranges and are continuous and non-overlapping; pressure thresholds within the first pressure threshold range are larger than pressure thresholds within the second pressure threshold range; and a first charge cutoff voltage of the plurality of predefined charge cutoff voltages corresponding to the first pressure threshold range is smaller than a second charge cutoff voltage of the plurality of predefined charge cutoff voltages corresponding to the second pressure threshold range, wherein the first charge cutoff voltage is a first upper limit voltage for charging the battery module when the acquired internal pressure value of the battery module is within the first pressure threshold range, and the second charge cutoff voltage is a second upper limit voltage for charging the battery module when the acquired internal pressure value of the battery module is within the second pressure threshold range.

2. The method of claim 1 , wherein: the controlling the battery module to be charged based on the obtained target charge cutoff voltage comprises:

controlling the battery module to be charged at a constant charging current until a voltage of the battery module reaches the target charge cutoff voltage; and

controlling the battery module to be charged at a constant charging voltage until a current of the battery module reaches a predefined charge cutoff current.

3. The method of claim 2 , wherein before controlling the battery module to be charged at a constant charging current until a voltage of the battery module reaches the target charge cutoff voltage, the method further comprises:

controlling the battery module to rest for a predetermined period of time.

4. The method of claim 1 , wherein: after controlling the battery module to be charged based on the obtained target charge cutoff voltage, the method further comprises:

controlling the battery module to be discharged at a constant discharging current until a voltage of the battery module reaches a predefined discharge cutoff voltage.

5. The method of claim 4 , wherein before controlling the battery module to be discharged at a constant discharging current until a voltage of the battery module reaches a predefined discharge cutoff voltage, the method further comprises:

controlling the battery module to rest for a predetermined period of time.

6. The method of claim 1 , further comprising:

acquiring a maximum pressure threshold in the plurality of predefined pressure threshold ranges;

comparing the internal pressure value of the battery module to the maximum pressure threshold; and

controlling the battery module to stop charging and discharging, when the internal pressure value of the battery module is larger than the maximum pressure threshold.

7. The method of claim 1 , further comprising:

acquiring a current module capacity of the battery module;

comparing the current module capacity of the battery module to an attenuation capacity threshold of the battery module; and

controlling the battery module to stop charging and discharging, when the current module capacity of the battery module is attenuated to the attenuation capacity threshold of the battery module.

8. The method of claim 1 , further comprising:

sensing the internal pressure value of the battery module by at least one pressure sensor provided on each battery cell in the battery module and/or between two adjacent battery cells in the battery module.

9. An apparatus for controlling charging of a battery module, comprising:

a pressure acquisition unit configured to acquire an internal pressure value of the battery module;

a pressure threshold range determination unit configured to determine a target pressure threshold range to which the acquired internal pressure value of the battery module belongs, based on a plurality of predefined pressure threshold ranges;

a lookup unit configured to obtain a target charge cutoff voltage corresponding to the target pressure threshold range, based on a correspondence relationship between a plurality of predefined charge cutoff voltages and the plurality of predefined pressure threshold ranges, wherein the target charge cutoff voltage is a target upper limit voltage for charging the battery module when the acquired internal pressure value of the battery module is within the target pressure threshold range; and

a charge control unit configured to control the battery module to be charged based on the obtained target charge cutoff voltage, wherein:

a first pressure threshold range and a second pressure threshold range are any two adjacent pressure threshold ranges selected from the plurality of predefined pressure threshold ranges and are continuous and non-overlapping; pressure thresholds within the first pressure threshold range are larger than pressure thresholds within the second pressure threshold range; and a first charge cutoff voltage of the plurality of predefined charge cutoff voltages corresponding to the first pressure threshold range is smaller than a second charge cutoff voltage of the plurality of predefined charge cutoff voltages corresponding to the second pressure threshold range wherein the first charge cutoff voltage is a first upper limit voltage for charging the battery module when the acquired internal pressure value of the battery module is within the first pressure threshold range, and the second charge cutoff voltage is a second upper limit voltage for charging the battery module when the acquired internal pressure value of the battery module is within the second pressure threshold range.

10. The apparatus of claim 9 , wherein the charge control unit is further configured to:

control the battery module to be charged at a constant charging current until a voltage of the battery module reaches the target charge cutoff voltage; and

control the battery module to be charged at a constant charging voltage until a current of the battery module reaches a predefined charge cutoff current.

11. The apparatus of claim 10 , wherein the charge control unit is further configured to:

control the battery module to rest for a predetermined period of time before controlling the battery module to be charged at a constant charging current until a voltage of the battery module reaches the target charge cutoff voltage.

12. The apparatus of claim 9 , further comprising:

a discharge control unit configured to control the battery module to be discharged at a constant discharging current until a voltage of the battery module reaches a predefined discharge cutoff voltage.

13. The apparatus of claim 12 , wherein the discharge control unit is further configured to:

control the battery module to rest for a predetermined period of time before controlling the battery module to be discharged at a constant discharging current until a voltage of the battery module reaches a predefined discharge cutoff voltage.

14. The apparatus of claim 9 , further comprising:

a maximum threshold acquisition unit configured to acquire a maximum pressure threshold in the plurality of predefined pressure threshold ranges;

a first comparison unit configured to compare the internal pressure value of the battery module to the maximum pressure threshold; and

a first charge and discharge stop unit configured to control the battery module to stop charging and discharging, when the internal pressure value of the battery module is larger than the maximum pressure threshold.

15. The apparatus of claim 9 , further comprising:

a module capacity acquisition unit configured to acquire a current module capacity of the battery module;

a second comparison unit configured to compare the current module capacity of the battery module to an attenuation capacity threshold of the battery module; and

a second charge and discharge stop unit configured to control the battery module to stop charging and discharging, when the current module capacity of the battery module is attenuated to the attenuation capacity threshold of the battery module.

16. A system for controlling charging of a battery module, comprising:

the apparatus for controlling charging of the battery module of claim 9 ; and

at least one pressure sensor provided on each battery cell in the battery module and/or between two adjacent battery cells in the battery module, and configured to sense an internal pressure of the battery module.