Method for determining potential difference of anode material, and electronic device and storage medium

Abstract

Provided in the present application are a method for determining a potential difference of an anode material, and an electronic device and a storage medium. The method comprises: predetermining a first potential difference estimation model for characterizing a relationship between the size of an anode material, a charging rate of a battery cell where the anode material is located, and a potential difference. Thus, to determine a potential difference of a first anode material, it is only necessary to obtain a first size and a charging rate of the first anode material, and the potential difference can be calculated on the basis of the predetermined first potential difference estimation model, thereby avoiding the use of a measurement apparatus to measure the potential difference between two ends of the first anode material, such that manpower and material resources are saved on, and measurement errors are prevented.

Description

Method for determining potential difference of negative electrode material, electronic device and storage medium

[0001] The present application claims priority to the Chinese patent application No. 2024108355335, filed on June 26, 2024, and titled "Method for determining potential difference of negative electrode material, electronic device and storage medium", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of batteries, in particular to a method for determining potential difference of negative electrode material, an electronic device and a storage medium. BACKGROUND

[0003] In recent years, blade batteries have been widely used in power battery systems of new energy vehicles due to their high space utilization, high power density and low cost, serving as the power source of new energy vehicles.

[0004] The negative electrode material is an important component of the blade battery, and uneven distribution of the potential of the negative electrode material will affect the fast charging performance of the blade battery. The part of the negative electrode material with a potential lower than the lithium precipitation potential will precipitate lithium, causing serious safety accidents.

[0005] Determining the potential difference between the tab side and the non-tab side of the negative electrode material can avoid the lithium precipitation phenomenon of the negative electrode material due to uneven potential distribution based on the design of the blade battery. However, the process of determining the potential difference between the tab side and the non-tab side of the negative electrode material in the prior art is too cumbersome. SUMMARY

[0006] The present application provides a method for determining the potential difference of the negative electrode material, an electronic device and a storage medium. The method uses a first potential difference estimation model to estimate the potential difference of the first negative electrode material, avoiding the use of measuring devices to measure the first negative electrode material. In this way, human resources can be saved, and measurement errors can also be avoided.

[0007] In a first aspect, the present application provides a method for determining the potential difference of the negative electrode material, comprising: obtaining the first size of the first negative electrode material of the first battery cell, and the first charging rate of the first battery cell when charging; determining the potential difference of the first negative electrode material based on the first size, the first charging rate and a first potential difference estimation model; the first potential difference estimation model is used to represent the relationship between the size of the negative electrode material, the charging rate of the battery cell where the negative electrode material is located and the potential difference of the negative electrode material; the potential difference of the negative electrode material is the potential difference between the tab of the negative electrode material and the opposite end of the tab.

[0008] In some embodiments, the first potential difference estimation model is: y = w1(k1 x1 + b1) + w2(k2 x2 + b2);

[0009] wherein y is the potential difference of the negative electrode material, w1 is a first factor, k1 is a second factor, x1 is the size of the negative electrode material, b1 is a third factor, w2 is a fourth factor, k2 is a fifth factor, x2 is the charge rate of the battery cell in which the negative electrode material is located, and b2 is a sixth factor; k1 and b1 are both related to x2, k2 and b2 are both related to x1, and w1 + w2 = 1.

[0010] In some embodiments, determining the potential difference of the first negative electrode material based on the first size, the first charge rate, and the first potential difference estimation model comprises: determining the value of the first factor in the first potential difference estimation model to be 1, to obtain a second potential difference estimation model; wherein the second potential difference estimation model is: y = k1 x1 + b1; based on the second potential difference estimation model, second factors corresponding to a plurality of second charge rates, third factors corresponding to the plurality of second charge rates, and the first size, a plurality of first potential differences are obtained; wherein the plurality of first potential differences are the potential differences of the first negative electrode material corresponding to the plurality of second charge rates respectively; the plurality of first potential differences and the plurality of second charge rates correspond one-to-one; and based on the correspondence between the plurality of first potential differences and the plurality of second charge rates, and the first charge rate, the potential difference of the first negative electrode material is determined.

[0011] In some embodiments, determining the potential difference of the first negative electrode material based on the first size, the first charge rate, and the first potential difference estimation model comprises: determining the value of the fourth factor in the first potential difference estimation model to be 1, to obtain a third potential difference estimation model; wherein the third potential difference estimation model is: y = k2 x2 + b2; based on the third potential difference estimation model, fifth factors corresponding to a plurality of second sizes, sixth factors corresponding to the plurality of second sizes, and the first charge rate, a plurality of second potential differences are obtained; wherein the plurality of second potential differences are the potential differences of the battery cells in which the plurality of second sizes of negative electrode materials are located, at the first charge rate; the plurality of second potential differences and the plurality of second sizes correspond one-to-one; and based on the correspondence between the plurality of second potential differences and the plurality of second sizes, and the first size, the potential difference of the first negative electrode material is determined.

[0012] In some embodiments, the second factor is positively correlated with the charge rate of the battery cell in which the negative electrode material is located, the third factor is negatively correlated with the charge rate of the battery cell in which the negative electrode material is located, the fifth factor is positively correlated with the size of the negative electrode material, and the sixth factor is negatively correlated with the size of the negative electrode material.

[0013] In some embodiments, the second factor corresponding to the second charging rate, the third factor corresponding to the second charging rate, the fourth factor corresponding to the second size, and the fifth factor corresponding to the second size are determined based on a first mapping table, the first mapping table comprising third potential differences of negative electrode materials of a plurality of third sizes measured at a plurality of third charging rates; wherein the plurality of third sizes comprises the plurality of second sizes, and the plurality of third charging rates comprises the plurality of second charging rates.

[0014] In some embodiments, determining the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate based on the first mapping table specifically comprises: obtaining, from the first mapping table, potential differences of all third sizes corresponding to the second charging rate; and determining the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate based on the potential differences of all third sizes and the all third sizes; and determining the fifth factor corresponding to the second size and the sixth factor corresponding to the second size based on the first mapping table specifically comprises: obtaining, from the first mapping table, potential differences of all third charging rates corresponding to the second size; and determining the fifth factor corresponding to the second size and the sixth factor corresponding to the second size based on the potential differences of all third charging rates and the all third charging rates.

[0015] In a second aspect, the present application provides a device for determining potential differences of negative electrode materials, comprising modules for implementing the method of the first aspect.

[0016] In a third aspect, the present application provides a chip comprising an interface circuit and a logic circuit, the interface circuit being configured to receive signals from other chips outside the chip and transmit the signals to the logic circuit, or send signals from the logic circuit to other chips outside the chip, and the logic circuit being configured to implement the method of the first aspect.

[0017] In a fourth aspect, the present application provides a storage medium having a computer program stored thereon, the computer program being executable by a processor to implement the method of the first aspect.

[0018] In a fifth aspect, the present application provides an electronic device comprising a memory and a processor, the memory storing a computer program executable by the processor, and the processor being configured to implement the method of the first aspect when executing the program.

[0019] In the embodiments of the present application, a first potential difference estimation model for representing the relationship between the size of the negative electrode material, the charge rate of the battery cell in which the negative electrode material is located, and the potential difference is predetermined. In this way, when determining the potential difference of the first negative electrode material, only the first size and the charge rate of the first negative electrode material need to be obtained, and the first potential difference estimation model is used to calculate and obtain the potential difference, thereby avoiding the use of a measuring device to measure the potential difference between the two ends of the first negative electrode material, saving manpower and resources and avoiding measurement errors. BRIEF DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a structural schematic diagram of a negative electrode sheet according to an embodiment of the present application;

[0021] FIG. 2 is a schematic diagram of the implementation process of a method for determining the potential difference of a negative electrode material according to an embodiment of the present application;

[0022] FIG. 3 is a schematic diagram of the implementation process of a method for determining the potential difference of a negative electrode material according to an embodiment of the present application;

[0023] FIG. 4 is a schematic diagram of a plurality of second charge rates and a plurality of first potential difference fitting curves according to an embodiment of the present application;

[0024] FIG. 5 is a schematic diagram of the implementation process of a method for determining the potential difference of a negative electrode material according to an embodiment of the present application;

[0025] FIG. 6 is a schematic diagram of the implementation process of a method for determining the potential difference of a negative electrode material according to an embodiment of the present application;

[0026] FIG. 7 is a schematic diagram of the implementation process of a method for determining the potential difference of a negative electrode material according to an embodiment of the present application;

[0027] FIG. 8 is a schematic diagram of a device for determining the potential difference of a negative electrode material according to an embodiment of the present application;

[0028] FIG. 9 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] A blade battery is composed of a large number of battery cells, protection circuits, housings, and other components. Among them, the battery cell is the core part of the battery, used to store and release electrical energy.

[0030] A battery cell is made of a positive electrode sheet, a negative electrode sheet, a separator, an electrolyte, and a housing according to a related process. The positive electrode sheet and the negative electrode sheet are separated by the separator, and the electrolyte is filled in them to form an electrochemical reaction environment, and the housing provides physical protection.

[0031] Among them, one end of the positive electrode sheet is connected to the positive electrode tab, and one end of the negative electrode sheet is connected to the negative electrode tab, and the positive electrode tab and the negative electrode tab serve as the contact point during charging and discharging of the battery cell.

[0032] FIG. 1 is a structural schematic diagram of a negative electrode sheet provided by the present application. As shown in FIG. 1, one end of the negative electrode sheet 10 is connected with a negative electrode tab 11. The negative electrode sheet and the negative electrode tab form a negative electrode material.

[0033] During the charging of the cell of the blade battery, the current flows along the length direction of the negative electrode material from the non-tab side to the tab side, so that there is a potential difference between the non-tab side and the tab side of the negative electrode material. Specifically, the potential decreases in turn along the direction from the non-tab side to the tab side.

[0034] When the length of the negative electrode material in the cell increases, the potential difference between the non-tab side and the tab side increases, and the potential of the tab side is lower than that of the non-tab side. When the length of the negative electrode material in the cell decreases, the potential difference between the non-tab side and the tab side decreases, and the potential of the tab side is still lower than that of the non-tab side.

[0035] When the charge rate of the cell increases, the potential difference between the non-tab side and the tab side increases, and the potential of the tab side is lower than that of the non-tab side. When the charge rate of the cell decreases, the potential difference between the non-tab side and the tab side decreases, and the potential of the tab side is still lower than that of the non-tab side.

[0036] It can be seen that the length of the negative electrode material, the charge rate of the cell, and the potential difference between the non-tab side and the tab side of the negative electrode material are related. During the charging process, the potential of the negative electrode material decreases in turn in the direction from the non-tab side to the tab side.

[0037] It can be seen that if the potential of the tab side is greater than the lithium precipitation potential during the design of the cell, the potential of the other part of the negative electrode material except the tab side is greater than the lithium precipitation potential, and the negative electrode material can avoid the lithium precipitation phenomenon.

[0038] The potential of the tab side can be obtained based on the potential difference between the non-tab side and the tab side of the negative electrode material and the potential of the non-tab side. Specifically: the potential of the tab side = the potential difference between the non-tab side and the tab side of the negative electrode material - the potential of the non-tab side.

[0039] Therefore, before designing the cell, the potential difference of the negative electrode material under different lengths and different charge rates can be determined to determine whether the potential of the tab side meets the lithium precipitation potential based on the potential difference of the negative electrode material and the potential of the non-tab side, so as to adjust the chemical system of the negative electrode material or the charge rate.

[0040] However, the blade battery is widely used in a large number of new energy vehicles, and in different application scenarios, the size of the negative electrode material in the blade battery cell and the charging rate of the blade battery during charging may be different. In the related art, the potential difference of the cell of each blade battery in all use scenarios is obtained by measurement. In this way, a measuring device needs to be added for each cell in the blade battery, which wastes manpower and resources.

[0041] Based on this, the present application provides a method for determining the potential difference of the negative electrode material. The method of the present application is applied to an electronic device with data processing capability. In the present application, the electronic device uses a first potential difference estimation model for representing the relationship between the size of the negative electrode material, the charging rate of the first cell and the potential difference of the negative electrode material to determine the potential difference of the first negative electrode material, thereby avoiding measuring the first negative electrode material by using a measuring device to obtain the first potential difference. In this way, human resources can be saved, and measurement errors can also be avoided.

[0042] FIG. 2 is a schematic diagram of the implementation process of the method for determining the potential difference of the negative electrode material according to an embodiment of the present application. As shown in FIG. 2, the method comprises:

[0043] S201, obtaining the first size of the first negative electrode material of the first cell, and the first charging rate of the first cell during charging.

[0044] It should be noted that the embodiments of the present application are applicable to negative electrode materials of any size and any charging rate. In the embodiments of the present application, the first negative electrode material with the first size is used as an example to illustrate how to determine the potential difference of the first negative electrode material at the first charging rate. The embodiments of the present application are also applicable to negative electrode materials of other different sizes and different charging rates.

[0045] The size of the negative electrode material can be the length of the negative electrode material, which can be approximately regarded as the length of the negative electrode sheet.

[0046] All the structures of the negative electrode materials involved in the embodiments of the present application can refer to FIG. 1, which includes a negative electrode sheet and a negative electrode tab. The potential difference of all the negative electrode materials involved in the embodiments of the present application is the potential difference between the negative electrode tab and the opposite end of the negative electrode tab.

[0047] It should be noted that the execution step of S101 can be before the use of the first cell or during the charging process of the first cell.

[0048] For example, before charging the first battery cell. The first battery cell is a battery cell to be designed. Before designing the first battery cell, the potential difference of the first negative electrode material is determined in advance according to the first size of the first negative electrode material and the first charge rate of the first battery cell when charging, and then it is estimated whether the lithium precipitation phenomenon will occur in the negative electrode sheet of the first battery cell when charging at the first charge rate according to the determined potential difference. If it is estimated that the lithium precipitation phenomenon will occur in the negative electrode sheet, the charge rate on which the first battery cell is charged can be changed. Based on the changed charge rate and the first size, the operation of determining the potential difference of the first negative electrode material and estimating whether the lithium precipitation phenomenon will occur in the first battery cell is performed again until it is estimated that the lithium precipitation phenomenon will not occur in the first battery cell when charging at the changed charge rate. When charging the first battery cell again, the first battery cell can be charged at the changed charge rate, so that the lithium precipitation phenomenon in the negative electrode sheet can be avoided, thereby avoiding safety hazards.

[0049] For example, during the process of charging the first battery cell, the potential difference of the first negative electrode material is determined based on the first charge rate and the size, and the chemical system design of the electrode sheet, electrolyte, etc. of the battery cell is adjusted according to the potential difference, so as to avoid lithium precipitation in the negative electrode.

[0050] In some embodiments, when designing the first battery cell, the first size and the first charge rate can be pre-set according to actual needs, and then the first size and the first charge rate are adaptively adjusted based on the potential difference calculated based on the first size and the first charge rate.

[0051] S202, determining the potential difference of the first negative electrode material based on the first size, the first charge rate and the first potential difference estimation model. The first potential difference estimation model is used to represent the relationship among the size of the negative electrode material, the charge rate of the battery cell in which the negative electrode material is located and the potential difference of the negative electrode material.

[0052] The first potential difference estimation model is determined in advance, which can be represented by the following formula one: y = w1(k1 x1 + b1) + w2(k2 x2 + b2); Formula one;

[0053] Wherein, y is the potential difference of the negative electrode material, w1 is the first factor, k1 is the second factor, x1 is the size of the negative electrode material, b1 is the third factor, w2 is the fourth factor, x2 is the charge rate of the battery cell in which the negative electrode material is located, k2 is the fifth factor, and b2 is the sixth factor; k1 and b1 are related to x2, k2 and b2 are related to x1, and w1 + w2 = 1.

[0054] k1 is related to x2, which can be positively correlated with x2, that is, k1 increases with the increase of x2.

[0055] b1 is related to x2, and can be positively correlated with x2, that is, b1 increases with the increase of x2.

[0056] k2 is related to x1, and can be negatively correlated with x1, that is, k2 decreases with the increase of x1.

[0057] b2 is related to x1, and can be negatively correlated with x1, that is, b2 decreases with the increase of x1.

[0058] As described above, k1 and b1 change with the change of x2, and x2 is different, k1 and b1 are different; k2 and b2 change with the change of x1, and x1 is different, k2 and b2 are different.

[0059] k1 and b1 are regarded as a first parameter group, and k2 and b2 are regarded as a second parameter group; w1(k1·x1+b1) is regarded as a first term in the formula one, and w2(k2·x2+b2) is regarded as a second term in the formula one.

[0060] When the second term in the formula one is fixed, the first parameter group is different, and the corresponding first formula is also different.

[0061] When the first term in the formula one is fixed, the second parameter group is different, and the corresponding first formula is also different.

[0062] In the above first potential difference estimation model, the determination modes of the second factor k1, the third factor b1, the fifth factor k2 and the sixth factor b2 are described in the following FIG. 6 and FIG. 7 embodiments, which are not described herein.

[0063] In some embodiments, the value range of k1 is 0-5.

[0064] The value range of b1 is -50-50.

[0065] The value range of k2 is 0-50.

[0066] The value range of b2 is -5-50.

[0067] After obtaining the first size and the first charging rate, the first size and the first charging rate are substituted into the above formula one, and the potential difference of the first size of the first negative electrode material when charged at the first charging rate can be obtained.

[0068] Substituting the first size and the first charging rate into the above formula one means that the first size is replaced by x1, and the first charging rate is replaced by x2.

[0069] In the embodiments of the present application, when the size is determined as the first size and the potential difference of the first negative electrode material is determined as the first charging rate, a first potential difference estimation model for representing the relationship among the size of the negative electrode material, the charging rate of the first battery and the potential difference of the negative electrode material is determined, and measurement of the negative electrode material by a measuring device is avoided. In this way, human resources can be saved and measurement errors can be avoided.

[0070] As described above, the first potential difference estimation model includes a first term and a second term, and when the potential difference of the first negative electrode material is determined, the determination can be based on the first term or the second term of the first potential difference estimation model. Next, the two determination methods are described through the embodiments of FIGS. 3 and 5.

[0071] FIG. 3 is a method for determining the potential difference of the negative electrode material provided by the embodiments of the present application. As shown in FIG. 3, S202 determining the potential difference of the first negative electrode material based on the first potential difference estimation model can be implemented through step a1 and step a3:

[0072] Step a1, determining that the value of the first factor in the first potential difference estimation model is 1, and obtaining a second potential difference estimation model.

[0073] As described above, the sum of the first factor w1 and the fourth factor w2 is 1, and w1 is 1, which means that the value of w2 is 0. In this case, the part of formula one: w2(k2·x2+b2) is 0.

[0074] Based on this, the second potential difference estimation model can be obtained as shown in formula two: y=k1·x1+b1 Formula two;

[0075] Step a2, based on the second potential difference estimation model, the second factors corresponding to the plurality of second charging rates, the third factors corresponding to the plurality of second charging rates and the first size, obtaining a plurality of first potential differences.

[0076] Among them, the plurality of first potential differences are the potential differences of the first negative electrode material corresponding to the plurality of second charging rates respectively, and the plurality of first potential differences and the plurality of second charging rates correspond one by one.

[0077] As described above, k1 and b1 (i.e. the first parameter group) are related to the charging rate, so different charging rates correspond to different first parameter groups (the first parameter groups are different, which means that k1 and b1 are different).

[0078] Then for the first parameter group corresponding to each second charging rate, the first size is brought into the formula two corresponding to the first parameter group, and the first potential difference corresponding to the second charging rate or the first parameter group can be obtained.

[0079] The step a3 determines the potential difference of the first negative electrode material based on the correspondence between the plurality of first potential differences and the plurality of second charge rates, and the first charge rate.

[0080] In some embodiments, the plurality of first potential differences and the plurality of second charge rates at the first size can be fitted to obtain a fitting curve. Then, the potential difference of the first negative electrode material with the first size is determined based on the first charge rate and a fitting formula corresponding to the fitting curve.

[0081] In some cases, if the plurality of second charge rates includes the first charge rate, the electronic device can directly obtain the potential difference corresponding to the first charge rate from the plurality of first potential differences. If the plurality of second charge rates does not include the first charge rate, the electronic device can determine the first charge rate based on the fitting formula.

[0082] Exemplarily, in the case of the first size being 400 mm, the first charge rate being 2.2C, and the second charge rates being 1C, 1.5C, 2C, 2.5C, 2.8C, and 3C, the first potential differences are shown in Table 1.

[0083] Table 1

[0084] The curve fitted by the plurality of second charge rates and the plurality of first potential differences is shown in FIG. 4, and the fitting formula is y = 14.617 * x2, where 14.617 is a fitting coefficient. By substituting the first charge rate 2.2C into the fitting curve, the potential difference of the negative electrode material of the battery cell with a length of 400 mm at a charge rate of 2.2 is 31.82 mV.

[0085] It should be noted that in the embodiments of the present application, the first size of 400 mm is only an example, and in actual use, the first size can be any value. The embodiments can estimate the correspondence between the first potential difference and the second charge rate at any size based on the first potential difference estimation model, so as to determine the potential difference at any size and any charge rate based on the correspondence.

[0086] Similar to the embodiment of FIG. 2, the potential difference of the first negative electrode material can also be determined by the second term of the first potential difference estimation model as shown in FIG. 5.

[0087] FIG. 5 is a method for determining the potential difference of the negative electrode material provided by the embodiments of the present application. As shown in FIG. 5, the step S202 of determining the potential difference of the first negative electrode material based on the first potential difference estimation model can be implemented by steps b1 and b3.

[0088] The step b1 determines the value of the fourth factor in the first potential difference estimation model as 1 to obtain a third potential difference estimation model.

[0089] As described above, the sum of the first factor w1 and the fourth factor w2 is 1, and w2 is 1, which means that the value of w1 is 0. In this case, the part of the formula one: w1(k1 x1+b1) is 0.

[0090] Based on this, the second potential difference estimation model can be obtained as shown in formula three: y=k2 x2+b2 Formula three

[0091] In step b2, based on the second potential difference estimation model, the fifth factor corresponding to each of the plurality of second sizes, the sixth factor corresponding to each of the plurality of second sizes, and the first charging rate, a plurality of second potential differences are obtained.

[0092] The plurality of second potential differences are the potential differences of the negative electrode materials of the plurality of second sizes at the first charging rate. The plurality of second potential differences and the plurality of second sizes correspond to each other.

[0093] As described above, k2 and b2 (i.e., the second parameter group) are related to the size of the negative electrode material, so different second sizes correspond to different second parameter groups (the second parameter groups are different, that is, k2 and b2 are different).

[0094] Then, for each second parameter group corresponding to each second size, the first charging rate is brought into the formula three corresponding to the second parameter group, and the second potential difference corresponding to the second size or the second parameter group can be obtained.

[0095] In step b3, based on the correspondence between the plurality of second potential differences and the plurality of second sizes, and the first size, the potential difference of the first negative electrode material is determined.

[0096] In some embodiments, the plurality of first potential differences and the plurality of second sizes at the first charging rate can be fitted to obtain a fitting curve. Then, based on the first size and the fitting formula corresponding to the fitting curve, the potential difference of the first negative electrode material of the first size at the first charging rate is determined.

[0097] In some cases, if the plurality of second sizes includes the first size, the electronic device can directly obtain the potential difference corresponding to the first size from the plurality of second sizes. If the plurality of second sizes does not contain the first size, the electronic device can determine the first size based on the fitting formula.

[0098] In this embodiment, when determining the potential difference of the first negative electrode material of the first size at the first charging rate, w2 in the first potential difference estimation model is determined as 1, so as to estimate the correspondence between the first potential difference and the second size at the first charging rate based on the second term in the first potential difference estimation model, and to determine the potential difference of the first negative electrode material of the first size at the first charging rate based on the correspondence.

[0099] As described above, the first parameter set is related to the second charging rate, and the first parameter set is different when the second charging rate is different. The second parameter set is related to the second size, and the second parameter set is different when the second size is different. Before using the first potential difference estimation model, it is necessary to determine the first parameter set corresponding to each second charging rate and the second parameter set corresponding to each second size.

[0100] In some embodiments, the first parameter set corresponding to the second charging rate and the second parameter set corresponding to the second size are determined based on a first mapping table. The first mapping table includes third potential differences measured at a plurality of third charging rates for a plurality of third sizes of negative electrode materials.

[0101] Next, the first parameter set corresponding to each second charging rate is determined by the following embodiment of FIG. 6. The second parameter set corresponding to each second size is determined by the following embodiment of FIG. 7.

[0102] FIG. 6 is a schematic diagram of an implementation flow of a negative electrode material potential difference determination method according to an embodiment of the present application. As shown in FIG. 6, before S201, it further includes:

[0103] S201a, from the first mapping table, obtaining the potential difference corresponding to all third sizes at the second charging rate.

[0104] Exemplarily, it is assumed that the first mapping table is shown in Table 2:

[0105] Table 2

[0106] Wherein, N is the number of third charging rates, M is the number of third sizes, A i is the i-th third charging rate, B j is the j-th third size, D ji is the potential difference corresponding to the third charging rate A i and the third size B j .

[0107] In the case where the plurality of third charging rates includes the second charging rate, it is assumed that the second charging rate is A2, and D 12 , D 22 ,..., D M2 are obtained from the mapping table.

[0108] S201b, based on the potential difference corresponding to all third sizes and all third sizes, determining the first parameter set corresponding to the second charging rate.

[0109] Determining the first parameter set corresponding to the second charging rate, that is, determining the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate.

[0110] In some embodiments, the linear fitting can be performed based on D 12 , D 22 ,..., D M2 , and B1, B2,..., B M to obtain the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate.

[0111] The essence of the linear fitting is to select a suitable k1 and b1 so that all the third sizes and the corresponding potential differences satisfy Y=k1*X1+b1 as much as possible. X1 is the third size, and Y is the potential difference.

[0112] In some embodiments, if the plurality of third charging rates does not include the second charging rate, the first parameter group corresponding to each third charging rate is determined.

[0113] Based on the first factor corresponding to each third charging rate, a fitting curve between the first factor and the third charging rate is determined, and the first factor corresponding to the second charging rate is determined based on the second charging rate and the fitting curve.

[0114] Based on the second factor corresponding to each third charging rate, a fitting curve between the second factor and the third charging rate is determined. The second factor corresponding to the second charging rate is determined based on the second charging rate and the fitting curve.

[0115] FIG. 7 is a schematic diagram of an implementation process of a method for determining a potential difference of a negative electrode material according to an embodiment of the present application. The method for determining the second parameter group corresponding to the second size is shown in FIG. 7, and before S201, the method further includes:

[0116] S201c, obtaining the potential differences corresponding to all the third charging rates under the second size from the first mapping table.

[0117] Exemplarily, the first mapping table is shown in Table 2.

[0118] In the case where the plurality of third sizes includes the second size, assuming that the second size is B2, D 21 , D 22 ,..., D 2N are obtained from the mapping table.

[0119] S201d, determining the second parameter group corresponding to the second size based on the potential differences corresponding to all the third charging rates and all the third charging rates.

[0120] The first parameter group corresponding to the second charging rate is determined, that is, the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate are determined.

[0121] In some embodiments, D 21, D 22 ,...., D 2N and A1, A2,..., A M , and a linear fitting is performed to obtain a fifth factor and a sixth factor corresponding to the second size.

[0122] The essence of the linear fitting is to select a suitable k2 and b2 so that all the third charge rates and the corresponding potential differences satisfy Y=k1*X2+b1 as much as possible. Here, X2 is the third charge rate, and Y is the potential difference.

[0123] In some embodiments, if the plurality of third sizes does not include the first size, for each third size, a second parameter group corresponding to the third size is determined.

[0124] Based on the fifth factor corresponding to each third size, a fitting curve between the fifth factor and the third size is determined, and the fifth factor corresponding to the second size is determined based on the second size and the fitting curve.

[0125] Based on the sixth factor corresponding to each third size, a fitting curve between the sixth factor and the third size is determined. The sixth factor corresponding to the second size is determined based on the second size and the fitting curve.

[0126] In this embodiment, the potential differences corresponding to the plurality of third sizes and the plurality of third rates are measured in advance to form a first mapping table, then the second potential differences corresponding to all the third charge rates under the second size are found in the first mapping table, the corresponding relationship between the third charge rate and the first potential difference is determined, and the potential difference under the second charge rate and the second size is determined based on the corresponding relationship.

[0127] It should be noted that in the embodiments of the present application, when measuring the third potential differences of the negative electrode materials of the plurality of third sizes under the plurality of third charge rates, the negative electrode materials are in a charged state and have the same state of charge (SOC).

[0128] For example, the third potential differences of the negative electrode materials of the plurality of third sizes under the plurality of third charge rates are all measured when the SOC of the battery cell is 50%. Then, the first potential difference of the first negative electrode material under the first charge rate determined based on the first potential difference estimation model is also the potential difference when the SOC of the battery cell is 50%.

[0129] Of course, the SOC of 50% is only an example. When the third potential difference of the plurality of third sizes of negative electrode materials at the plurality of third charge rates is measured, the measurement can also be performed at an SOC of 20%, 30%, or other SOC, and then the first potential difference of the first size of the first negative electrode material at the first charge rate is determined based on the measured third potential difference of the plurality of third sizes of negative electrode materials at the plurality of third charge rates, which is the potential difference at the corresponding SOC.

[0130] It should be noted that although the steps of the method in the present application are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired result. In addition or alternatively, some steps can be omitted, a plurality of steps can be combined into one step, and / or one step can be divided into a plurality of steps, etc.; or, the steps in different embodiments can be combined into a new technical solution.

[0131] Based on the foregoing embodiments, the present application provides a negative electrode material potential difference determination device, which comprises the modules included therein and the units included in the modules, and can be implemented by a processor; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP), or a field programmable gate array (FPGA), etc.

[0132] FIG. 8 is a structural schematic diagram of the negative electrode material potential difference determination device provided by the embodiments of the present application, as shown in FIG. 8, the negative electrode material potential difference determination device 80 comprises an acquisition module 81 and a determination module 82, wherein:

[0133] The acquisition module 81 is configured to acquire a first size of a first negative electrode material of a first battery cell, and a first charge rate of the first battery cell when charging.

[0134] The determination module 82 is configured to determine a potential difference of the first negative electrode material based on the first size, the first charge rate, and a first potential difference estimation model; the first potential difference estimation model is used to represent the relationship among the size of the negative electrode material, the charge rate of the battery cell in which the negative electrode material is located, and the potential difference of the negative electrode material; the potential difference of the negative electrode material is the potential difference between the tab of the negative electrode material and the tab at the opposite end of the tab.

[0135] In some embodiments, the first potential difference estimation model is y=w1(k1·x1+b1)+w2(k2·x2+b2);

[0136] wherein y is a potential difference of the negative electrode material, w1 is a first factor, k1 is a second factor, x1 is a size of the negative electrode material, b1 is a third factor, w2 is a fourth factor, k2 is a fifth factor, x2 is a charge rate of a battery cell in which the negative electrode material is located, and b2 is a sixth factor; k1 and b1 are both related to x2, k2 and b2 are both related to x1, and w1 + w2 = 1.

[0137] In some embodiments, the determining module 82 is configured to determine that the value of the first factor in the first potential difference estimation model is 1, to obtain a second potential difference estimation model; wherein the second potential difference estimation model is y = k1 x1 + b1; based on the second potential difference estimation model, second factors corresponding to a plurality of second charge rates, third factors corresponding to the plurality of second charge rates, and the first size, to obtain a plurality of first potential differences; wherein the plurality of first potential differences are potential differences of the first negative electrode material corresponding to the plurality of second charge rates respectively; the plurality of first potential differences and the plurality of second charge rates correspond to each other one by one; and based on the correspondence between the plurality of first potential differences and the plurality of second charge rates, and the first charge rate, to determine the potential difference of the first negative electrode material.

[0138] In some embodiments, the determining module 82 is configured to determine that the value of the fourth factor in the first potential difference estimation model is 1, to obtain a third potential difference estimation model; wherein the third potential difference estimation model is y = k2 x2 + b2; based on the third potential difference estimation model, fifth factors corresponding to a plurality of second sizes, sixth factors corresponding to the plurality of second sizes, and the first charge rate, to obtain a plurality of second potential differences; wherein the plurality of second potential differences are potential differences of the negative electrode materials of the plurality of second sizes in the battery cells respectively under the first charge rate; the plurality of second potential differences and the plurality of second sizes correspond to each other one by one; and based on the correspondence between the plurality of second potential differences and the plurality of second sizes, and the first size, to determine the potential difference of the first negative electrode material.

[0139] In some embodiments, the second factor is positively correlated with the charge rate of the battery cell in which the negative electrode material is located, the third factor is negatively correlated with the charge rate of the battery cell in which the negative electrode material is located, the fifth factor is positively correlated with the size of the negative electrode material, and the sixth factor is negatively correlated with the size of the negative electrode material.

[0140] In some embodiments, the second factor corresponding to the second charging rate, the third factor corresponding to the second charging rate, the fourth factor corresponding to the second size, and the fifth factor corresponding to the second size are determined based on a first mapping table, the first mapping table comprising third potential differences of negative electrode materials of a plurality of third sizes measured at a plurality of third charging rates; wherein the plurality of third sizes comprises the plurality of second sizes, and the plurality of third charging rates comprises the plurality of second charging rates.

[0141] In some embodiments, the determining module 82 is configured to: obtain, from the first mapping table, potential differences of all third sizes at the second charging rate; and determine the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate based on the potential differences of all third sizes and the all third sizes; and determine the fifth factor corresponding to the second size and the sixth factor corresponding to the second size based on the first mapping table, specifically comprising: obtaining, from the first mapping table, potential differences of all third charging rates at the second size; and determining the sixth factor corresponding to the second size and the fifth factor corresponding to the second size based on the potential differences of all third charging rates and the all third charging rates.

[0142] The above description of the device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects to the method embodiments. For technical details not disclosed in the device embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0143] It should be noted that the division of the modules of the negative electrode material potential difference determination device shown in FIG. 8 in the embodiments of the present application is illustrative, and is only a logical functional division. In actual implementation, there can be another division manner. In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or can be physically separated, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware, or in the form of a software functional unit. It can also be realized in the form of a combination of software and hardware.

[0144] It should be noted that, in the embodiments of the present application, if the above-mentioned method for determining the potential difference of the negative electrode material is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions for causing an electronic device to execute all or part of the method described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk, and various media that can store program codes. Thus, the embodiments of the present application are not limited to any specific combination of hardware and software.

[0145] The embodiments of the present application provide a chip, including an interface circuit and a logic circuit, the interface circuit is used for receiving signals from other chips outside the chip and transmitting to the logic circuit, or sending signals from the logic circuit to other chips outside the chip, and the logic circuit is used for implementing the method for determining the potential difference of the negative electrode material described in the embodiments of the present application.

[0146] The embodiments of the present application provide an electronic device. FIG. 9 is a structural schematic diagram of an electronic device according to an embodiment of the present application. As shown in FIG. 9, the electronic device 90 includes a memory 901 and a processor 902, the memory 901 stores a computer program executable on the processor 902, and the processor 902 implements the steps in the method provided in the above-mentioned embodiments when executing the program.

[0147] It should be noted that the memory 901 is configured to store instructions and applications executable by the processor 902, and can also buffer data (for example, image data, audio data, voice communication data and video communication data) to be processed or having been processed in the processor 902 and each module of the electronic device 90, which can be implemented by a flash memory (FLASH) or a random access memory 901 (RAM).

[0148] The embodiments of the present application provide a computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps in the method for determining the potential difference of the negative electrode material provided in the above-mentioned embodiments.

[0149] The embodiments of the present application provide a computer program product containing instructions, which, when executed on a computer, cause the computer to perform the steps in the method for determining the potential difference of the negative electrode material provided in the above-mentioned method embodiments.

[0150] It should be noted that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium, storage medium and device embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0151] It should be understood that the "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiments are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" or "in some embodiments" appearing throughout the specification does not necessarily mean the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The sequence number of the above embodiments of the present application is only for description, not representing the advantages and disadvantages of the embodiments. The above description of each embodiment tends to emphasize the differences between each embodiment, and the same or similar parts can be referred to each other, and for the sake of brevity, this paper will not be repeated here.

[0152] The term "and / or" in this paper is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, object A and / or object B, which can represent the following three cases: object A exists alone, object A and object B exist together, and object B exists alone.

[0153] It should be noted that in this paper, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0154] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other manners. The embodiments described above are merely exemplary, for example, the division of the modules is only a logical function division, and there can be another division manner for the actual implementation, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the various components shown or discussed can be indirect coupling or communication connection through some interfaces, devices or modules, and can be electrical, mechanical or other forms.

[0155] The modules described above as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules; they can be located in one place, or distributed on multiple system units; and some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments.

[0156] In addition, each functional module in each embodiment of the present application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated module can be realized in the form of hardware or in the form of hardware plus software functional unit.

[0157] Those of ordinary skill in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by a program instructing related hardware, and the foregoing program can be stored in a computer readable storage medium, and the program executes the steps of the above-mentioned method embodiments when executed; and the foregoing storage medium includes mobile storage devices, read only memory (ROM), magnetic discs or optical discs and various storage media that can store program codes.

[0158] Alternatively, the integrated units of the present application, if implemented in the form of software functional modules and sold or used as independent products, can also be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, and includes several instructions for causing an electronic device to execute all or part of the methods described in the embodiments of the present application. The foregoing storage medium includes mobile storage devices, ROM, magnetic discs or optical discs and various storage media that can store program codes.

[0159] The methods disclosed in the several method embodiments provided by the present application can be combined arbitrarily without conflict, to obtain new method embodiments.

[0160] The features disclosed in several product embodiments provided by the present application can be arbitrarily combined, without conflict, to obtain new product embodiments.

[0161] The features disclosed in several method or device embodiments provided by the present application can be arbitrarily combined, without conflict, to obtain new method embodiments or device embodiments.

[0162] The above description is merely illustrative of the application, and the scope of the application is not limited thereto. Any modifications or changes within the scope of the application should be covered by the scope of the application. Therefore, the scope of the application should be determined by the scope of the claims.

Claims

1. A method for determining the potential difference of a negative electrode material, characterized in that, The method includes: Obtain the first dimension of the first negative electrode material of the first battery cell, and the first charging rate of the first battery cell during charging; Based on the first size, the first charging rate, and the first potential difference prediction model, the potential difference of the first negative electrode material is determined; the first potential difference prediction model is used to characterize the relationship between the size of the negative electrode material, the charging rate of the cell in which the negative electrode material is located, and the potential difference of the negative electrode material; the potential difference of the negative electrode material is the potential difference between the tab of the negative electrode material and the end opposite to the tab.

2. The method according to claim 1, characterized in that, The first potential difference prediction model is: y = w1(k1·x1+b1) + w2(k2·x2+b2); Where y is the potential difference of the negative electrode material, w1 is the first factor, k1 is the second factor, x1 is the size of the negative electrode material, b1 is the third factor, w2 is the fourth factor, k2 is the fifth factor, x2 is the charging rate of the cell where the negative electrode material is located, and b2 is the sixth factor; k1 and b1 are both related to x2, k2 and b2 are both related to x1, and w1+w2=1.

3. The method according to claim 2, characterized in that, The step of determining the potential difference of the first negative electrode material based on the first size, the first charging rate, and the first potential difference prediction model includes: The value of the first factor in the first potential difference prediction model is determined to be 1, and the second potential difference prediction model is obtained; wherein, the second potential difference prediction model is: y=k1·x1+b1; Based on the second potential difference prediction model, the second factors corresponding to the multiple second charging rates, the third factors corresponding to the multiple second charging rates, and the first size, multiple first potential differences are obtained; wherein, the multiple first potential differences are the potential differences of the first negative electrode material at the multiple second charging rates respectively; the multiple first potential differences and the multiple second charging rates correspond one-to-one; Based on the correspondence between the plurality of first potential differences and the plurality of second charging rates, and the first charging rate, the potential difference of the first negative electrode material is determined.

4. The method according to claim 2, characterized in that, The step of determining the potential difference of the first negative electrode material based on the first size, the first charging rate, and the first potential difference prediction model includes: The value of the fourth factor in the first potential difference prediction model is determined to be 1, thus obtaining the third potential difference prediction model; wherein, the third potential difference prediction model is: y=k2·x2+b2; Based on the third potential difference prediction model, the fifth factors corresponding to the multiple second dimensions, the sixth factors corresponding to the multiple second dimensions, and the first charging rate, multiple second potential differences are obtained; wherein, the multiple second potential differences are the potential differences of the cells containing the negative electrode materials of the multiple second dimensions at the first charging rate; the multiple second potential differences correspond one-to-one with the multiple second dimensions; Based on the correspondence between the plurality of second potential differences and the plurality of second dimensions, and the first dimension, the potential difference of the first negative electrode material is determined.

5. The method according to claim 2, characterized in that, The second factor is positively correlated with the charging rate of the cell containing the negative electrode material, the third factor is negatively correlated with the charging rate of the cell containing the negative electrode material, the fifth factor is positively correlated with the size of the negative electrode material, and the sixth factor is negatively correlated with the size of the negative electrode material.

6. The method according to claim 2, characterized in that, The second factor corresponding to the second charging rate, the third factor corresponding to the second charging rate, the fourth factor corresponding to the second size, and the fifth factor corresponding to the second size are determined based on a first mapping table. The first mapping table includes a third potential difference measured for a negative electrode material of a plurality of third sizes at a plurality of third charging rates. The plurality of third sizes include the plurality of second sizes, and the plurality of third charging rates include the plurality of second charging rates.

7. The method according to claim 6, characterized in that, Based on the first mapping table, the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate are determined, specifically including: Obtain the potential difference corresponding to all third dimensions under the second charging rate from the first mapping table; Based on the potential difference corresponding to all the third dimensions, and the all the third dimensions, determine the second factor corresponding to the second charging rate and the third factor corresponding to the second charging rate; Determining the fifth factor and the sixth factor corresponding to the second size based on the first mapping table specifically includes: Obtain the potential difference corresponding to all third charging rates under the second size from the first mapping table; Based on the potential difference corresponding to all the third charging rates, and all the third charging rates, determine the fifth factor corresponding to the second size and the sixth factor corresponding to the second size.

8. A device for determining the potential difference of a negative electrode material, characterized in that, Includes a module that performs the method according to any one of claims 1 to 7.

9. An electronic device, characterized in that, The method includes a memory and a processor, the memory storing a computer program that can run on the processor, the processor executing the program to implement the method of any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 7.

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