A lithium ion battery soc correction method, system, device and medium

Abstract

The application discloses a lithium ion battery SOC correction method, system, device and medium, wherein the lithium ion battery SOC correction method comprises the following steps: acquiring the static voltage of a target battery; judging whether the static voltage is in the voltage platform region of the target battery; if not, correcting the current SOC of the target battery through a lithium ion battery OCV-SOC curve; if yes, requesting a cloud to calculate a SOC correction value, the cloud calling the voltage information and current information of the target battery before static to calculate the changed capacity after entering the voltage platform region, the cloud acquiring the interval capacity and interval SOC value corresponding to the voltage platform region, calculating the correction value SOCx according to the changed capacity, the interval capacity and the interval SOC value, and correcting the current SOC of the target battery according to the correction value SOCx. The application does not need to modify the existing BMS hardware, reduces the modification cost, corrects the SOC of the lithium ion battery in the voltage platform region, and improves the SOC estimation accuracy of the lithium ion battery.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, specifically to a method, system, device, and medium for correcting the state of charge (SOC) of a lithium-ion battery. Background Technology

[0002] The use of lithium batteries is inseparable from the Battery Management System (BMS). As a key component ensuring the normal and safe use of batteries and improving battery life, one of the core functions of the BMS is State of Charge (SOC) estimation. SOC reflects the current remaining capacity of the battery, defined as the percentage of its current remaining capacity relative to its total capacity.

[0003] Current common methods for estimating State of Charge (SOC) include ampere-hour integration and static voltage correction. However, ampere-hour integration suffers from unavoidable errors due to current sampling errors during long-term use. A common SOC correction method involves using static voltage to look up values ​​in an OCV curve. However, when applied to LFP (lithium iron phosphate) battery systems, the presence of a significant OCV voltage plateau in LFP batteries, coupled with limited accuracy in single-cell voltage acquisition, makes it impossible to accurately correct the SOC value in the plateau region.

[0004] Existing technologies, such as Chinese Patent No. CN110967644A, disclose a method for correcting the SOC of a battery pack, a battery management system, and a vehicle. This patent describes SOC correction using capacity differentiation in the non-degradation region of SOC-OCV, correcting the SOC value of the battery pack during charging. This avoids the impact of battery aging on the calculation of the battery pack's SOC value and improves the accuracy of the corrected SOC value. However, this patent only corrects the SOC range in the non-degradation region. Furthermore, it requires OCV testing using cells with different degrees of degradation to identify the non-degradation region, making it highly dependent on cell R&D data. Summary of the Invention

[0005] To solve the above problems, the technical solution provided by the present invention is as follows:

[0006] A method for correcting the state of charge (SOC) of a lithium-ion battery, including

[0007] Obtain the static voltage of the target battery; collect the individual cell voltage, current and temperature in real time during the charging and discharging process of the target battery;

[0008] Determine whether the static voltage is within the voltage plateau region of the target battery;

[0009] If the static voltage is not in the voltage plateau region, the current SOC of the target battery is corrected using the lithium-ion battery OCV-SOC curve;

[0010] If the static voltage is within the voltage plateau region, a request is made to the cloud to calculate the SOC correction value. The cloud retrieves the voltage and current information of the target battery before it is placed at rest to calculate the changed capacity after entering the voltage plateau region. The cloud obtains the interval capacity and interval SOC value corresponding to the voltage plateau region, calculates the correction value SOCx based on the changed capacity, the interval capacity, and the interval SOC value, and corrects the current SOC of the target battery based on the correction value SOCx.

[0011] The present invention is further configured to call the voltage charging / discharging curve and current charging / discharging curve of the target battery before it is placed in the cloud, calculate the capacity differential curve during the charging / discharging process of the target battery before it is placed in the cloud, and calculate the area of ​​the capacity differential curve by the voltage at the end of the charging / discharging of the target battery, so as to obtain the change capacity of the target battery after it enters the voltage plateau region.

[0012] The present invention is further configured such that the change capacity of the target battery entering the voltage plateau region during the charging / discharging process is Qs; the interval capacity corresponding to the voltage plateau region is Qc; and the interval SOC values ​​corresponding to the voltage plateau region are SOCa and SOCb, wherein SOCb > SOCa.

[0013] During the charging process of the target battery, the correction value SOCx = SOCa + Qs / Qc × (SOCb - SOCa) is used. At this time, the change in capacity Qs is the capacity accumulated by the target battery after entering the voltage plateau region.

[0014] During the discharge process of the target battery, the correction value SOCx = SOCb - Qs / Qc × (SOCb - SOCa) is used, where the change in capacity Qs is the capacity consumed by the target battery after it enters the voltage plateau region.

[0015] The present invention is further configured such that the cloud stores the charging / discharging curves of the target battery under typical temperature and no capacity decay, and the cloud also records the charging / discharging curves of the target battery for each complete charge, so as to obtain the charging / discharging capacity differential curves under different temperatures and different capacity decay levels.

[0016] The present invention is further configured to, when requesting cloud calculation of SOC correction value, use temperature and capacity decay degree as indexes to search the cloud database for the charge / discharge capacity differential curve corresponding to the temperature and capacity decay degree;

[0017] If the cloud database contains a charging / discharging capacity differential curve corresponding to the temperature and the degree of capacity decay, then the charging / discharging capacity differential curve corresponding to the temperature and the degree of capacity decay is called to calculate the interval capacity and interval SOC value corresponding to the voltage plateau region.

[0018] If the cloud database does not contain a charge / discharge capacity differential curve corresponding to the temperature and the degree of capacity decay, then the charge / discharge capacity differential curve adjacent to the temperature and the degree of capacity decay is called, and the interval capacity and interval SOC value corresponding to the voltage plateau region are calculated using an interpolation algorithm.

[0019] The present invention is further configured such that if the static voltage is in the voltage plateau region, the current SOC0 of the target battery is obtained, and the correction value SOCx returned by the cloud is received. If |SOCx-SOC0|≥n, where n is the first correction threshold, then the correction is performed by increasing or decreasing the rate of SOC change of the target battery during the charging process.

[0020] The present invention is further configured such that if the static voltage is not in the voltage plateau region, the current SOC0 of the target battery is obtained, and the correction value SOCx corresponding to the OCV-SOC curve of the lithium-ion battery is queried according to the static voltage. If |SOCx-SOC0|≥m, where m is the second correction threshold, then the correction is performed by increasing or decreasing the SOC change rate of the target battery during the charging process.

[0021] A lithium-ion battery SOC correction system, employing the aforementioned lithium-ion battery SOC correction method, includes:

[0022] The target battery needs to be corrected;

[0023] The Battery Management Unit (BMS) collects the static voltage of the target battery and simultaneously collects real-time data on individual cell voltage, current, and temperature during the charging process. When the static voltage of the target battery is outside the voltage plateau region, it determines whether to correct the current SOC of the target battery based on the lithium-ion battery OCV-SOC curve. When the static voltage of the target battery is in the voltage plateau region, it sends a calculation request to the cloud and determines whether to correct the current SOC of the target battery based on the correction value returned by the cloud.

[0024] The cloud storage and computing unit stores the charging / discharging curves of the target battery under typical temperature and no capacity decay conditions, as well as the charging / discharging curves of each complete charge of the target battery; it receives calculation requests sent by the battery management unit (BMS), calls the voltage and current information of the target battery before it is placed at rest to calculate the changed capacity after entering the voltage plateau region, obtains the interval capacity and interval SOC value corresponding to the voltage plateau region, calculates a correction value based on the changed capacity, the interval capacity, and the interval SOC value, and returns it to the battery management unit (BMS);

[0025] The data transmission unit is used to transmit calculation requests, static voltage, single cell voltage, current, and temperature data sent by the battery management unit (BMS) to the cloud storage and computing unit; and to transmit correction values ​​returned by the cloud storage and computing unit to the battery management unit (BMS).

[0026] An electronic device includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the aforementioned lithium-ion battery SOC correction method.

[0027] A storage medium storing computer program instructions, which, when executed by a processor, implement the above-described lithium-ion battery SOC correction method.

[0028] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0029] This invention provides a lithium-ion battery SOC correction method that categorizes and corrects batteries based on whether their static voltage is in the voltage plateau region or not. For target batteries with static voltage in the non-voltage plateau region, the correction value is obtained by directly querying the lithium-ion battery OCV-SOC curve. The correction value is then compared with the target battery's current SOC to determine whether SOC correction should be performed. For target batteries with static voltage in the voltage plateau region, a calculation request is sent to the cloud. The cloud retrieves the voltage and current information of the target battery before it enters the voltage plateau region to calculate the capacity change after entering the voltage plateau region. The range capacity and range SOC value corresponding to the voltage plateau region are obtained. The correction value is calculated based on the capacity change, range capacity, and range SOC value and returned to the battery management unit (BMS). The BMS determines whether to correct the current SOC of the target battery based on the correction value returned by the cloud.

[0030] This invention utilizes the massive storage space and computing power of the cloud to continuously store the charging / discharging information of the target battery. When the static voltage of the target battery is in the voltage plateau region, it combines the voltage and current information of the target battery before it was placed at rest to calculate the capacity change after entering the voltage plateau region, and calculates the interval capacity and interval SOC value corresponding to the voltage plateau region based on the complete charging and discharging information of the target battery in the past. The correction value is then calculated and returned to the battery management unit (BMS). This eliminates the need to modify the existing BMS hardware, reducing modification costs, and improves the accuracy of SOC estimation by correcting the SOC of lithium-ion batteries in the voltage plateau region.

[0031] The cloud storage and computing unit in this invention also establishes charge and discharge curves of the target battery under different temperatures and different capacity decay levels to obtain the corresponding capacity differential curve. When the cloud storage and computing unit receives a calculation request from the battery management unit (BMS), it can call the capacity differential curve with the same temperature and the same decay level as the current battery state, thereby further reducing the correction error. Attached Figure Description

[0032] Figure 1 This is a flowchart of the lithium-ion battery SOC correction method according to an embodiment of the present invention.

[0033] Figure 2 This is an OCV-SOC curve of a lithium-ion battery according to an embodiment of the present invention.

[0034] Figure 3 This is a typical standard charging voltage-SOC variation curve of an embodiment of the present invention.

[0035] Figure 4 This is a typical standard charging capacity differential (dQ / dV-V) curve diagram of an embodiment of the present invention.

[0036] Figure 5 This is a block diagram of a lithium-ion battery SOC correction system according to an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram of the device according to an embodiment of the present invention. Detailed Implementation

[0038] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection, or a connection within two components; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0041] Example 1

[0042] Combined with appendix Figure 1 To be continued Figure 4 The present invention provides a method for correcting the state of charge (SOC) of a lithium-ion battery, including...

[0043] Obtain the static voltage of the target battery; collect the individual cell voltage, current and temperature in real time during the charging and discharging process of the target battery;

[0044] Determine whether the static voltage is within the voltage plateau region of the target battery;

[0045] If the static voltage is not in the voltage plateau region, the current SOC of the target battery is corrected using the lithium-ion battery OCV-SOC curve;

[0046] If the static voltage is within the voltage plateau region, a request is made to the cloud to calculate the SOC correction value. The cloud retrieves the voltage and current information of the target battery before it is placed at rest to calculate the changed capacity after entering the voltage plateau region. The cloud obtains the interval capacity and interval SOC value corresponding to the voltage plateau region, calculates the correction value SOCx based on the changed capacity, the interval capacity, and the interval SOC value, and corrects the current SOC of the target battery based on the correction value SOCx.

[0047] In the above embodiments, the lithium-ion battery SOC correction method classifies and corrects batteries with static voltage in the voltage plateau region and those without. For target batteries with static voltage in the non-voltage plateau region, the correction value is obtained by directly querying the lithium-ion battery OCV-SOC curve. The correction value is compared with the current SOC of the target battery to determine whether to perform SOC correction. For target batteries with static voltage in the voltage plateau region, a calculation request is sent to the cloud. The cloud retrieves the voltage and current information of the target battery before it is placed at rest to calculate the change in capacity after entering the voltage plateau region. The range capacity and range SOC value corresponding to the voltage plateau region are obtained. The correction value is calculated based on the change in capacity, range capacity, and range SOC value and returned to the battery management unit (BMS). The BMS determines whether to correct the current SOC of the target battery based on the correction value returned by the cloud.

[0048] In the above embodiments, the static voltage is determined by a current less than x that lasts for more than y time; for example, a specific determination condition is a current less than 1A that lasts for more than 1 hour. The monitoring and determination of the static voltage are managed by the Battery Management Unit (BMS).

[0049] In this embodiment, the cloud retrieves the voltage charging / discharging curve and current charging / discharging curve of the target battery before it is left to stand, calculates the capacity differential curve during the charging / discharging process of the target battery before it is left to stand, and calculates the area of ​​the capacity differential curve by the voltage at the end of the charging / discharging of the target battery, so as to obtain the change in capacity of the target battery after it enters the voltage plateau region.

[0050] In this embodiment, the change in capacity of the target battery entering the voltage plateau region during charging / discharging is Qs; the interval capacity corresponding to the voltage plateau region is Qc; the interval SOC values ​​corresponding to the voltage plateau region are SOCa and SOCb, where SOCb > SOCa;

[0051] During the charging process of the target battery, the correction value SOCx = SOCa + Qs / Qc × (SOCb - SOCa) is used. At this time, the change in capacity Qs is the capacity accumulated by the target battery after entering the voltage plateau region.

[0052] During the discharge process of the target battery, the correction value SOCx = SOCb - Qs / Qc × (SOCb - SOCa) is used, where the change in capacity Qs is the capacity consumed by the target battery after it enters the voltage plateau region.

[0053] In the above embodiment, the variable capacity Qs is obtained by the cloud calling the voltage charging / discharging curve and current charging / discharging curve of the target battery before it is placed at rest, calculating the capacity differential curve during the charging / discharging process of the target battery before it is placed at rest, and calculating the area of ​​the capacity differential curve by the voltage at the end of the charging / discharging of the target battery.

[0054] In the above embodiment, the capacity Qc corresponding to the voltage platform region is obtained based on the complete charging / discharging curves already available in the cloud. In order to obtain more accurate (smaller deviation) complete charging / discharging curves, a database is established based on the factors that affect the complete charging / discharging curves—temperature and capacity decay—using these two factors as variables. This allows the cloud to store a large number of complete charging / discharging curves under different temperatures and different capacity decay levels. The following is a detailed explanation.

[0055] In this embodiment, the cloud pre-stores the charging / discharging curves of the target battery under typical temperature and no capacity decay. During the subsequent charging and discharging process of the target battery, the cloud also records the charging / discharging curves of the target battery for each complete charge, so as to obtain the differential charging / discharging capacity curves under different temperatures and different capacity decay levels.

[0056] In the above embodiments, the massive storage space and computing power of the cloud are utilized to continuously store the charging information of the target battery. When the static voltage of the target battery is in the voltage plateau region, the voltage and current information of the target battery before it is placed at rest are combined to calculate the capacity change after entering the voltage plateau region. Combined with the complete charge and discharge information of the target battery in the past, the corresponding range capacity and range SOC value of the voltage plateau region are calculated. A correction value is then calculated and returned to the battery management unit (BMS). This eliminates the need to modify the existing BMS hardware, reducing modification costs. It also improves the accuracy of SOC estimation for lithium-ion batteries in the voltage plateau region.

[0057] In this embodiment, when a cloud-based calculation of the SOC correction value is requested, the charging / discharging capacity differential curve corresponding to the temperature and capacity decay level is searched in the cloud database using temperature and capacity decay level as indexes.

[0058] If the cloud database contains a charging / discharging capacity differential curve corresponding to the temperature and the degree of capacity decay, then the charging / discharging capacity differential curve corresponding to the temperature and the degree of capacity decay is called to calculate the interval capacity and interval SOC value corresponding to the voltage plateau region.

[0059] If the cloud database does not contain a charge / discharge capacity differential curve corresponding to the temperature and the degree of capacity decay, then the charge / discharge capacity differential curve adjacent to the temperature and the degree of capacity decay is called, and the interval capacity and interval SOC value corresponding to the voltage plateau region are calculated using an interpolation algorithm.

[0060] In the above embodiments, the cloud storage and computing unit establishes charge and discharge curves of the target battery under different temperatures and different capacity decay levels to obtain the corresponding capacity differential curve. When the cloud storage and computing unit receives a calculation request from the battery management unit (BMS), it can call the capacity differential curve with the same temperature and the same decay level as the current battery state, thereby further reducing the correction error.

[0061] In this embodiment, if the static voltage is in the voltage plateau region, the current SOC0 of the target battery is obtained, and the correction value SOCx returned from the cloud is received. If |SOCx-SOC0|≥n, where n is the first correction threshold, then the correction is performed by increasing or decreasing the SOC change rate of the target battery during the charging process.

[0062] In this embodiment, if the static voltage is not in the voltage plateau region, the current SOC0 of the target battery is obtained, and the correction value SOCx corresponding to the OCV-SOC curve of the lithium-ion battery is queried according to the static voltage. If |SOCx-SOC0|≥m, where m is the second correction threshold, then the correction is performed by increasing or decreasing the SOC change rate of the target battery during the charging process.

[0063] In the above embodiments, the first correction threshold and the second correction threshold may differ in value, or they may be the same in value.

[0064] In the above embodiments, regardless of whether the static voltage is in the voltage plateau region and |SOCx-SOC0|≥n, or the static voltage is not in the voltage plateau region and |SOCx-SOC0|≥m, the SOC change rate of the target battery is adjusted according to the subsequent operating conditions. For example, if the currently reported value SOC0 is 30%, and the corrected value SOCx obtained through static cell voltage is 40%, the error is -10%, and the SOC needs to be corrected to increase. However, because SOC cannot change abruptly, SOC0 cannot be directly changed to 40%. Assuming the subsequent operating condition is continued charging, and the correction rate is assumed to be 1% / min, then 1% needs to be added to the ampere-hour integral (SOC increases) per minute, thus increasing the SOC change rate. Assuming the subsequent operating condition is continuous discharging, and again assuming a correction rate of 1% / min, then 1% needs to be added to the ampere-hour integral (SOC decreases) per minute, thus decreasing or reducing the SOC change rate.

[0065] To further illustrate this technical solution, the following example is provided:

[0066] As attached Figure 2 The figure shows the OCV-SOC curve of a lithium-ion battery. The OCV of a lithium-ion battery has obvious voltage plateau regions [V1,V2] and [V3,V4]. The SOC values ​​corresponding to the voltage plateau regions [V1,V2] and [V3,V4] are SOC1, SOC2, SOC3, and SOC4, respectively. When the battery management unit (BMS) collects the static voltage V0, it starts the correction process.

[0067] If the static voltage V0 is not in the voltage plateau region, i.e., V0 < V1, V2 < V0 < V3, or V4 < V0, the correction value SOCx is obtained by querying the OCV-SOC curve. Based on the difference between the correction value SOCx and the current SOC0 reported by the battery management unit (BMS), it is determined whether to perform SOC correction. The correction steps are as described above and will not be repeated here.

[0068] As shown in the attached figure Figure 3As shown, it is a typical standard charging voltage - SOC change curve graph, stored in the cloud, and there are also two voltage platform regions [V5, V6] and [V7, V8] like the OCV - SOC curve. Using the voltage change curve of the complete charging process, differentiating the voltage with respect to the capacity can obtain the capacity differential curve (dQ / dV - V) of the complete charging process. A typical capacity differential curve of the charging process is as attached Figure 1 It can be observed that there is a peak point between V5 and V6, and there is a peak point between V7 and V8. The interval capacity Q of the voltage platform region [V5, V6] can be obtained by calculating the area under the capacity differential curve Figure 4 or the interval capacity Q of the voltage platform region [V7, V8] 56 78 .

[0069] If the static voltage V0 is in the voltage platform region, taking the example that after constant - current charging, the battery management unit BMS collects the static voltage and V1 < V0 < V2, the cloud calls the voltage charging curve and current charging curve of the target battery before standing, calculates the capacity differential curve during the charging process of the target battery before standing, calculates the change capacity Ql after the target battery enters the voltage platform region by calculating the area of the capacity differential curve, and calculates the correction value SOCx = SOC1 + Q1 / Q 56 ×(SOC2 - SOC1), and returns the correction value SOCx to the battery management unit BMS. The battery management unit BMS judges whether to correct the SOC according to the difference between the correction value SOCx and the current SOC0 reported by the battery management unit BMS

[0070] Embodiment 2

[0071] Combined with the attached Figure 5 , the technical solution of the present invention is a lithium - ion battery SOC correction system, adopting the lithium - ion battery SOC correction method described in Embodiment 1, including:

[0072] The target battery 10 to be corrected;

[0073] The battery management unit BMS20, which collects the static voltage of the target battery, and simultaneously collects the monomer voltage, current, and temperature data in real - time during the charging process of the target battery; when the static voltage of the target battery is in the non - voltage platform region, it judges whether to correct the current SOC of the target battery through the lithium - ion battery OCV - SOC curve; when the static voltage of the target battery is in the voltage platform region, it sends a calculation request to the cloud and judges whether to correct the current SOC of the target battery according to the correction value returned by the cloud

[0074] ​The cloud storage and computing unit 30 stores the charging / discharging curves of the target battery under typical temperature and no capacity decay conditions, as well as the charging / discharging curves of each complete charge of the target battery; it obtains the calculation request sent by the battery management unit (BMS), calls the voltage and current information of the target battery before it is placed at rest to calculate the changed capacity after entering the voltage plateau region, obtains the interval capacity and interval SOC value corresponding to the voltage plateau region, calculates a correction value based on the changed capacity, the interval capacity, and the interval SOC value, and returns it to the battery management unit (BMS);

[0075] The data transmission unit 40 is used to transmit calculation requests, static voltage, single cell voltage, current, and temperature data sent by the battery management unit (BMS) to the cloud storage and computing unit; and to transmit correction values ​​returned by the cloud storage and computing unit to the battery management unit (BMS).

[0076] Example 3

[0077] Combined with appendix Figure 6 An electronic device includes a memory 200 and a processor 100. The memory stores a computer program, which, when executed by the processor 100, causes the processor 100 to perform the lithium-ion battery SOC correction method described in Embodiment 1.

[0078] Example 4

[0079] A storage medium storing computer program instructions, which, when executed by a processor, implement the above-described lithium-ion battery SOC correction method.

[0080] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for correcting the state of charge (SOC) of a lithium-ion battery, characterized in that, include Obtain the static voltage of the target battery; collect the individual cell voltage, current and temperature in real time during the charging and discharging process of the target battery; Determine whether the static voltage is within the voltage plateau region of the target battery; If the static voltage is not in the voltage plateau region, the current SOC of the target battery is corrected using the lithium-ion battery OCV-SOC curve; If the static voltage is in the voltage plateau region, a request is made to the cloud to calculate the SOC correction value. The cloud calls the voltage and current information of the target battery before it is placed at rest to calculate the change in capacity after entering the voltage plateau region. The cloud obtains the interval capacity and interval SOC value corresponding to the voltage plateau region, calculates the correction value SOCx based on the change in capacity, the interval capacity and the interval SOC value, and corrects the current SOC of the target battery based on the correction value SOCx. The cloud retrieves the voltage charging / discharging curve and current charging / discharging curve of the target battery before it is left to stand, calculates the capacity differential curve during the charging / discharging process of the target battery before it is left to stand, and calculates the area of ​​the capacity differential curve by the voltage at the end of the charging / discharging of the target battery, so as to obtain the change in capacity of the target battery after it enters the voltage plateau region. The change in capacity of the target battery during charging / discharging into the voltage plateau region is Qs; the interval capacity corresponding to the voltage plateau region is Qc; the interval SOC values ​​corresponding to the voltage plateau region are SOCa and SOCb, where SOCb > SOCa; During the charging process of the target battery, the correction value SOCx = SOCa + Qs / Qc × (SOCb - SOCa) is used. At this time, the change in capacity Qs is the capacity accumulated by the target battery after entering the voltage plateau region. During the discharge process of the target battery, the correction value SOCx = SOCb - Qs / Qc × (SOCb - SOCa) is used, where the change in capacity Qs is the capacity consumed by the target battery after it enters the voltage plateau region.

2. The lithium-ion battery SOC correction method according to claim 1, characterized in that, The cloud storage contains the charging / discharging curves of the target battery under typical temperatures and without capacity decay. The cloud also records the charging / discharging curves of the target battery for each complete charge, in order to obtain the differential charging / discharging capacity curves under different temperatures and different degrees of capacity decay.

3. The lithium-ion battery SOC correction method according to claim 2, characterized in that, When requesting the cloud to calculate the SOC correction value, the cloud database is searched for the charge / discharge capacity differential curve corresponding to the temperature and the degree of capacity decay, using temperature and capacity decay as indexes. If the cloud database contains a charging / discharging capacity differential curve corresponding to the temperature and the degree of capacity decay, then the charging / discharging capacity differential curve corresponding to the temperature and the degree of capacity decay is called to calculate the interval capacity and interval SOC value corresponding to the voltage plateau region. If the cloud database does not contain a charge / discharge capacity differential curve corresponding to the temperature and the degree of capacity decay, then the charge / discharge capacity differential curve adjacent to the temperature and the degree of capacity decay is called, and the interval capacity and interval SOC value corresponding to the voltage plateau region are calculated using an interpolation algorithm.

4. A method for correcting the state of charge (SOC) of a lithium-ion battery according to any one of claims 1 to 3, characterized in that, If the static voltage is in the voltage plateau region, the current SOC0 of the target battery is obtained, and the correction value SOCx returned from the cloud is received. If |SOCx-SOC0|≥n, where n is the first correction threshold, then the correction is performed by increasing or decreasing the rate of SOC change of the target battery during the charging process.

5. A method for correcting the state of charge (SOC) of a lithium-ion battery according to any one of claims 1 to 3, characterized in that, If the static voltage is not in the voltage plateau region, the current SOC0 of the target battery is obtained, and the correction value SOCx corresponding to the OCV-SOC curve of the lithium-ion battery is queried according to the static voltage. If |SOCx-SOC0|≥m, where m is the second correction threshold, then the correction is performed by increasing or decreasing the SOC change rate of the target battery during the charging process.

6. A lithium-ion battery SOC correction system, characterized in that, The lithium-ion battery SOC correction method according to any one of claims 1 to 5 includes: The target battery needs to be corrected; The Battery Management Unit (BMS) collects the static voltage of the target battery and simultaneously collects real-time data on individual cell voltage, current, and temperature during the charging process. When the static voltage of the target battery is outside the voltage plateau region, it determines whether to correct the current SOC of the target battery based on the lithium-ion battery OCV-SOC curve. When the static voltage of the target battery is in the voltage plateau region, it sends a calculation request to the cloud and determines whether to correct the current SOC of the target battery based on the correction value returned by the cloud. The cloud storage and computing unit stores the charging / discharging curves of the target battery under typical temperature and no capacity decay conditions, as well as the charging / discharging curves of each complete charge of the target battery; it receives calculation requests sent by the battery management unit (BMS), calls the voltage and current information of the target battery before it is placed at rest to calculate the changed capacity after entering the voltage plateau region, obtains the interval capacity and interval SOC value corresponding to the voltage plateau region, calculates a correction value based on the changed capacity, the interval capacity, and the interval SOC value, and returns it to the battery management unit (BMS); The data transmission unit is used to transmit calculation requests, static voltage, single cell voltage, current, and temperature data sent by the battery management unit (BMS) to the cloud storage and computing unit; and to transmit correction values ​​returned by the cloud storage and computing unit to the battery management unit (BMS).

7. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the lithium-ion battery SOC correction method according to any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium stores computer program instructions, which, when executed by a processor, implement the lithium-ion battery SOC correction method according to any one of claims 1 to 5.

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