Battery module analysis method, device and electronic equipment

Abstract

The present invention provides a battery module analysis method, device and electronic device, including: predicting a target swelling force corresponding to a battery module through a target swelling prediction model; performing swelling simulation on the battery module based on the target swelling force to determine a target swelling cell from cells included in the battery module; and determining a swelling analysis result corresponding to the battery module according to the target swelling cell. The present invention can significantly reduce the amount of data required for analyzing swelling conditions in a battery module, and can also significantly improve analysis efficiency.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery module analysis method, device and electronic equipment. Background Art

[0002] During the process of charging or discharging the battery module, the battery cells in the battery module may produce corresponding chemical gases during the chemical reaction of charging and discharging, causing the battery cells to swell and deform to a certain extent, thereby generating external swelling force, which will have a certain impact on the battery module structure. The related technology proposes to use a battery cell swelling force detection system to measure the swelling force generated by the battery cells when swelling and deforming occurs. Using the battery cell swelling force detection system to perform swelling analysis on the battery module not only requires measuring a large amount of swelling force data, but also has the problem of low measurement efficiency. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a battery module analysis method, device and electronic equipment, which can significantly reduce the amount of data required for analyzing the swelling condition in the battery module and significantly improve the analysis efficiency.

[0004] In a first aspect, an embodiment of the present invention provides a method for analyzing a battery module, comprising: predicting a target swelling force corresponding to a battery module through a target swelling prediction model; performing swelling simulation on the battery module based on the target swelling force to determine a target swelling cell from the cells included in the battery module; and determining a swelling analysis result corresponding to the battery module according to the target swelling cell.

[0005] In one embodiment, before predicting the target swelling force corresponding to the battery module through the target swelling prediction model, it also includes: acquiring the measured swelling data corresponding to the battery module; wherein the measured swelling data is obtained by performing a cyclic expansion test on the battery module under a specified environment; and fitting the model parameters of the initial swelling model according to the measured swelling data to obtain the target swelling prediction model.

[0006] In one embodiment, predicting the target swelling force corresponding to the battery module by using the target swelling prediction model includes: obtaining a specified number of cycles corresponding to the battery module, and predicting the target swelling force corresponding to the battery module based on the specified number of cycles by using the target swelling prediction model.

[0007] In one embodiment, the battery module is subjected to swelling simulation based on the target swelling force to determine a target swelling cell from the battery cells included in the battery module, comprising: performing swelling simulation on the battery module based on the relative position of each battery cell in the battery module and the target swelling force to obtain an amount of swelling deformation corresponding to each battery cell; and determining a target swelling cell from the battery cells included in the battery module according to the amount of swelling deformation corresponding to each battery cell.

[0008] In one embodiment, determining the swelling analysis result corresponding to the battery module according to the target swelling cell includes: determining the force applied by the target swelling cell to a specified component in the battery module according to the target swelling force; calculating the ratio of a stress threshold corresponding to the specified component to the force; if the ratio is less than a preset safety factor, determining that the swelling analysis result corresponding to the battery module is an abnormality of the battery module.

[0009] In one embodiment, determining the swelling analysis result corresponding to the battery module according to the target swollen battery cell further includes: calculating the distance value between the target swollen battery cell and the water cooling plate in the battery module based on the swelling deformation amount corresponding to the target swollen battery cell; if the distance value is greater than or equal to the original thickness value of the heat conductive structure in the battery module, determining that the swelling analysis result corresponding to the battery module is abnormal; wherein the heat conductive structure is arranged between the target swollen battery cell and the water cooling plate.

[0010] In one embodiment, determining the swelling analysis result corresponding to the battery module based on the target swollen battery cell further includes: if the swelling deformation corresponding to the target swollen battery cell is greater than or equal to the anti-swelling structure length of the aluminum bar in the battery module, determining that the swelling analysis result corresponding to the battery module is abnormal.

[0011] In a second aspect, an embodiment of the present invention further provides an analysis device for a battery module, comprising: a swelling force prediction module, used to predict a target swelling force corresponding to the battery module through a preconfigured target swelling prediction model; a battery cell determination module, used to perform swelling simulation on the battery module based on the target swelling force, so as to determine a target swelling battery cell from the battery cells included in the battery module; and a swelling analysis module, used to determine a swelling analysis result corresponding to the battery module according to the target swelling battery cell.

[0012] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement any one of the methods provided in the first aspect.

[0013] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement any one of the methods provided in the first aspect.

[0014] An analysis method, device and electronic device for a battery module provided in an embodiment of the present invention first predicts a target swelling force corresponding to the battery module through a target swelling prediction model, and performs swelling simulation on the battery module based on the target swelling force, so as to determine a target swelling cell from the cells included in the battery module, and then determines a swelling analysis result corresponding to the battery module according to the target swelling cell. The above method can predict the target swelling force corresponding to the battery module using a target swelling prediction model, thereby performing swelling simulation on the battery module based on the target swelling force to obtain a target swelling cell, and swelling analysis results can be obtained according to the target swelling cell. Compared with the method of measuring a large amount of swelling force using relevant equipment in the prior art, the embodiment of the present invention can significantly reduce the amount of data required for analyzing the swelling situation in the battery module, and can also significantly improve the analysis efficiency.

[0015] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of a flow chart of a battery module analysis method provided by an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the structure of a battery module provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a capacity retention rate curve provided by an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of an inflation force curve provided by an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of the structure of another battery module provided by an embodiment of the present invention;

[0023] Figure 6 A schematic diagram of a battery cell swelling and deformation provided by an embodiment of the present invention;

[0024] Figure 7 A schematic diagram of another type of battery cell swelling and deformation provided by an embodiment of the present invention;

[0025] Figure 8 A schematic diagram of a force applied to a designated component provided by an embodiment of the present invention;

[0026] Fig. 9 A schematic diagram of another force applied to a designated component provided by an embodiment of the present invention;

[0027] Fig.10 A schematic diagram of another force applied to a designated component provided by an embodiment of the present invention;

[0028] Fig.11 A schematic cross-sectional view of a weld area provided in an embodiment of the present invention;

[0029] Fig.12 A schematic diagram of the structure of another battery module provided by an embodiment of the present invention;

[0030] Fig.13 A schematic diagram of the structure of another battery module provided by an embodiment of the present invention;

[0031] Fig.14 A schematic diagram of the structure of another battery module provided by an embodiment of the present invention;

[0032] Fig.15 A schematic diagram of the structure of an aluminum bar provided in an embodiment of the present invention;

[0033] Fig.16 A schematic diagram of the internal structure of a battery cell provided by an embodiment of the present invention;

[0034] Fig.17 A schematic diagram of electrolyte infiltration provided by an embodiment of the present invention;

[0035] Fig.18 A schematic diagram of a diaphragm hole provided by an embodiment of the present invention;

[0036] Fig.19 A schematic diagram of the structure of a battery module analysis device provided by an embodiment of the present invention;

[0037] Fig. 20 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described in combination with the embodiments below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] At present, the existing technology not only needs to measure a large amount of swelling force data, but also has the problem of low measurement efficiency. Based on this, the present invention implements a battery module analysis method, device and electronic equipment, which can significantly reduce the amount of data required for analyzing the swelling situation in the battery module and significantly improve the analysis efficiency.

[0040] To facilitate understanding of this embodiment, a battery module analysis method disclosed in an embodiment of the present invention is first described in detail. Figure 1 The flowchart of a battery module analysis method shown in FIG. 1 mainly includes the following steps S102 to S106:

[0041] Step S102, predicting the target swelling force corresponding to the battery module by using the target swelling prediction model. The input of the target swelling prediction model is the cycle number, and the output is the swelling force corresponding to the cycle number. In one embodiment, multiple cycle numbers can be input to determine the maximum swelling force from the swelling forces corresponding to each cycle number, and the maximum swelling force is used as the target swelling force.

[0042] Step S104, performing swelling simulation on the battery module based on the target swelling force to determine the target swelling cell from the cells included in the battery module. In one embodiment, the battery module is a battery module simulation model rather than a real battery module, and the swelling deformation amount of each cell in the simulation model under the target swelling force state is determined, so as to determine the target swelling cell from each cell based on the swelling deformation amount.

[0043] Step S106, determining the swelling analysis result corresponding to the battery module according to the target swelling cell. The swelling analysis result is used to characterize whether the battery module is normal or abnormal under the above-mentioned target fault force state. In one embodiment, the target swelling cell can be used to detect whether the specified component in the battery module is cracked, whether the thermal conductive structure meets the thermal management requirements, whether the aluminum bar meets the buffering requirements, etc., so as to obtain the corresponding swelling analysis result.

[0044] The battery module analysis method provided in the embodiment of the present invention can use the target swelling prediction model to predict the target swelling force corresponding to the battery module, thereby performing swelling simulation on the battery module based on the target swelling force to obtain a target swelling cell, and the swelling analysis result can be obtained according to the target swelling cell. Compared with the method of using relevant equipment to measure a large amount of swelling force in the prior art, the embodiment of the present invention can significantly reduce the amount of data required for analyzing the swelling situation in the battery module, and can also significantly improve the analysis efficiency.

[0045] To facilitate understanding of the aforementioned target swelling prediction model, the embodiment of the present invention further provides an implementation method for establishing a target swelling prediction model, specifically:

[0046] (1) Obtain the actual swelling data corresponding to the battery module. The actual swelling data is obtained by performing a cyclic swelling test on the battery module under a specified environment. Figure 2 A schematic diagram of the structure of a battery module is shown in FIG. Figure 2 The battery module is shown to include a circular gasket and a winding core. The circular gasket only presses down part of the winding core through the battery shell, and the force on the circular gasket is borne by the battery shell. The above-mentioned swelling measured data includes the actual parameters of the material except the winding core. The actual parameters can include the number of cycles and the measured swelling force corresponding to each cycle number. In addition, the swelling measured data also includes obtaining the measured elastic modulus of the winding core.

[0047] (2) Fitting the model parameters of the initial swelling model according to the measured swelling data to obtain the target swelling prediction model. In one embodiment, the initial swelling prediction model can be established by the Arrhenius equation, and the swelling force of the battery cell can be simulated by the temperature rise method, so as to calibrate the model parameters of the initial swelling prediction model to obtain the desired target swelling prediction model. In the specific implementation, the expansion force can be set to 16000N as the target, and the thermal expansion coefficient can be adjusted according to the measured elastic modulus of the winding core. In addition, the worst conditions such as tolerance, maximum value state of the battery cell or minimum value state of the battery cell are considered for simulation, and the temperature rise Δt is adjusted to a suitable value so that the expansion force calculated by the simulation is equal to the measured expansion force. Under the simulation condition, the above-mentioned number of cycles and the measured swelling force corresponding to each number of cycles are input, and the model parameters of the initial swelling model are fitted to obtain the formula for predicting the swelling force in the target swelling prediction model. In another embodiment, the capacity retention rate can also be determined by the swelling force borne by the core part at a certain number of cycles, so as to fit the formula for predicting the capacity retention rate in the target swelling prediction model according to the capacity retention rate and the number of cycles. For example, assuming that the swelling force borne by the core part at the Nth cycle is 16000N, the health state of the battery cell at this time is determined to be 70% SOH, and the capacity retention rate can be obtained by calculating the product of the battery cell capacity and the battery cell health state.

[0048] For example, assuming that the ambient temperature is 45°C and the average cell temperature is 49.2°C during simulation, the target swelling prediction model is as follows:

[0049] Cap.=(100-0.9971*x -0.4555 +11.01) / 100;

[0050]

[0051] Wherein, cap. is the capacity retention rate, Force is the predicted swelling force, and x is the specified number of cycles. Based on the above target swelling prediction model, the embodiment of the present invention also provides the following Figure 3 A schematic diagram of a capacity retention rate curve is shown in FIG. Figure 4 A schematic diagram of an expansion force curve is shown.

[0052] On the basis of the above embodiment, when the target swelling force corresponding to the battery module is predicted by the target swelling prediction model, the specified cycle number corresponding to the battery module can be obtained, and the target swelling force corresponding to the battery module can be predicted based on the specified cycle number by the target swelling prediction model. Exemplarily, when the specified cycle number x=3554, the capacity retention rate can be determined to be 70.53% based on the above target swelling prediction model, and the target swelling force is 1579.22kgf, i.e. 15476.356N.

[0053] For the aforementioned step S104, the embodiment of the present invention further provides an implementation method of performing swelling simulation on the battery module based on the target swelling force to determine the target swelling battery cell from the battery cells included in the battery module, see the following steps 1 to 2:

[0054] Step 1: Based on the relative position of each battery cell in the battery module and the target swelling force, the battery module is subjected to swelling simulation to obtain the swelling deformation corresponding to each battery cell. The relative position includes the relative position between the battery cell and the end plate, the relative position between the battery cells, and the relative position between the battery cell and the circular gasket. For example, see Figure 5 The schematic diagram of the structure of another battery module shown in FIG. 1 includes 12 battery cells. Based on the above target swelling force, simulation analysis is performed. Since the relative position of each battery cell is different, different swelling deformations will be generated, such as Figure 6 A schematic diagram of a battery cell swelling and deformation is shown in FIG. Figure 7 Another schematic diagram of a battery cell swelling and deformation is shown in FIG. Figure 7Taking the expansion and deformation of battery cells as an example to illustrate, there will be three types of deformation after the battery cells in the battery module swell, such as battery cell No. 1 has no expansion space and is squeezed by battery cell No. 2, battery cell No. 2 squeezes battery cell No. 1 and battery cell No. 3, and one side of battery cell No. 3 is squeezed by battery cell No. 2, and the corresponding expansion deformation of each battery cell is measured.

[0055] Step 2: Determine the target swollen cell from the cells included in the battery module according to the swelling deformation amount corresponding to each cell. In one embodiment, the target swollen cell can be selected in descending order of swelling deformation amount. For example, cell No. 8 has the largest swelling deformation amount of 0.14 mm, so cell No. 8 is determined as the target swollen cell.

[0056] In another embodiment, the target swollen battery cell may also be determined according to the type of swelling deformation of the battery cell, such as using the above-mentioned No. 1 battery cell, No. 2 battery cell and No. 3 battery cell as the target swollen battery cells respectively.

[0057] For the aforementioned step S106, the embodiment of the present invention also provides some implementation methods for determining the swelling analysis result corresponding to the battery module according to the target swelling cell, see the following methods 1 to 3:

[0058] Method 1: Determine whether a designated component is cracked based on a target swollen cell, specifically: (1) Determine the force applied by the target swollen cell to a designated component in the battery module based on the target swelling force; (2) Calculate the ratio of the stress threshold corresponding to the designated component to the force; (3) If the ratio is less than a preset safety factor, determine that the swelling analysis result corresponding to the battery module is abnormal; (4) If the ratio is greater than or equal to the preset safety factor, determine that the swelling analysis result corresponding to the battery module is normal.

[0059] The above-mentioned designated parts may include battery cell shells, battery cell welds, end plates, side plates, side plate welds, aluminum bars, battery shells, shell welds, etc. The stress threshold may be the maximum strength or tensile strength that the designated part can withstand, and the preset safety factor may be set to 1.1 or 1.2.

[0060] Taking the battery cell shell and battery cell weld as an example, determine the force applied by battery cell No. 1 on the battery cell shell and battery cell weld, the force applied by battery cell No. 2 on the battery cell shell and battery cell weld, and the force applied by battery cell No. 3 on the battery cell shell and battery cell weld, assuming that the battery cell shell can withstand a maximum strength of 168Mp, and the battery cell cover weld (that is, the above-mentioned battery cell weld) can withstand a maximum strength of 117.6Mp. Figure 8The schematic diagram of a specified component under stress is shown. Taking the force applied by cell No. 1 on the battery case as an example, the simulation determines that the maximum force applied by cell No. 1 on the battery case is 132.4Mpa, and determines that the ratio of the maximum strength that the battery case can withstand to the maximum force is equal to 1.27. This ratio is used as the simulation safety factor, and it is determined that the simulation safety factor is greater than the above-mentioned preset safety factor, and it is determined that the battery case will not crack. Similarly, based on Figure 8 It can be seen that the three battery cells are subjected to different stresses, but the strength of the battery cell shell and the battery cell weld meet the requirements, the battery cell shell will not crack, and the battery module is normal.

[0061] Taking the end plate, side plate, side plate weld, aluminum bar, battery shell, and shell weld as examples, the tensile strength of the end plate is 280MPa, the tensile strength of the side plate is 305MPa, the tensile strength of the side plate weld is 196MPa, the tensile strength of the aluminum bar is 88.3MPa, the tensile strength of the battery can is 168MPa, and the tensile strength of the battery can bead is 117.6MPa. The first simulation conditions include: (1) When the part tolerance and assembly deviation take the middle value, the battery module strength meets the maximum expansion force requirement, and the safety factor standard is determined to be ≥1.2; (2) the compression amount of the circular gasket (1.37mm); (3) the compression area of ​​the circular gasket (1896.8mm 2 ); (4) 70% SOH maximum bulging force (16000N); (5) welding weld length (75mm). For example, see Fig. 9 Another schematic diagram of the stress of a designated component is shown. Under the first simulation condition, the end plate stress is determined to be 223.1MPa, and the simulation safety factor is 1.25; the side plate stress is 197.9Mpa, and the simulation safety factor is 1.54; the weld stress is 137Mpa, and the simulation safety factor is 1.43; the aluminum row stress is 56.28Mpa, and the simulation safety factor is 1.57; the battery shell stress is 132.4MPa, and the simulation safety factor is 1.27; the shell weld stress is 94.17, and the simulation safety factor is 1.25. In summary, under the first simulation condition, the designated components will not crack, and the battery module is normal.

[0062] Continuing with the end plate, side plate, side plate weld, aluminum bar, battery shell, and shell weld as examples, the second simulation conditions include: (1) module strength, worst conditions, maximum expansion force requirements, and safety factor standard ≥ 1.1; (2) maximum compression of the circular gasket (1.143 mm); (3) minimum compression area of ​​the circular gasket (1654.72 mm 2) ; (4) 70% SOH maximum bulging force (16000N); (5) minimum length of welding weld (73mm). For example, see Fig.10Another schematic diagram of the stress of a specified component is shown. Under the first simulation condition, the end plate stress is determined to be 239Mpa, with a simulation safety factor of 1.17; the side plate stress is 222Mpa, with a simulation safety factor of 1.37; the weld stress is 145Mpa, with a simulation safety factor of 1.35; the aluminum bar stress is 64.7Mpa, with a simulation safety factor of 1.36; the battery shell stress is 151Mpa, with a simulation safety factor of 1.11; the shell weld stress is 106.9Mpa, with a simulation safety factor of 1.10. It should be noted that the aluminum bar and the battery core weld area can be simulated for the aluminum bar weld deformation, such as Fig.11 A schematic diagram of a cross-sectional view of a weld area is shown, the initial weld area S = 40.4 ± 9 mm2, the conductive bar weld area is reduced to 31.312 mm2, the deformation △S = 31.4-31.312 = 0.088, within the welding tolerance (±9), meeting the requirements. In summary, under the second simulation condition, the specified components will not crack, and the battery module is normal.

[0063] Method 2: Determine whether the thermal conductive structure meets the thermal management requirements based on the target swollen battery cell. Specifically: (1) Based on the swelling deformation corresponding to the target swollen battery cell, calculate the distance value between the target swollen battery cell and the water cooling plate in the battery module; (2) If the distance value is greater than or equal to the original thickness value of the thermal conductive structure in the battery module, determine that the swelling analysis result corresponding to the battery module is abnormal; wherein the thermal conductive structure is arranged between the target swollen battery cell and the water cooling plate. In practical applications, the thermal conductive structure in the battery module can adopt a thermal conductive pad, and the above-mentioned water cooling plate can adopt a rigid water cooling plate or an elastic water cooling plate.

[0064] Taking a rigid water cooling plate as an example, the thickness of the thermal pad should fill the gap between the water cooling plate and the bottom of the battery cell. Fig.12 A schematic diagram of the structure of another battery module is shown in FIG. Fig.12 It shows that the height difference between the bottom of the end plate and the battery cell is 1.65mm, see Fig.13 The structural schematic diagram of another battery module shown in FIG. 1 shows that, based on the bottom tolerance of the battery module (±0.4), the flatness of the water-cooling plate (±0.5), and the flatness of the bottom angle of the end plate (±0.1), the cumulative tolerance from the bottom of the battery cell to the surface of the water-cooling plate is determined to be 0.6 mm using the following cumulative tolerance formula:

[0065] In addition, the deformation of the bottom of the battery cell under bulging condition is 0.14mm, the thickness tolerance of the thermal pad is ±0.1mm, and the original thickness of the thermal pad is 2.5mm. Based on the above parameters, the distance between the target bulging battery cell and the water cooling plate in the battery module can be calculated as: 1.65mm+0.6mm+0.14mm+0.1=2.49mm. It can be seen that the original thickness of the thermal pad is greater than the distance value, which confirms that the thermal pad can fill the gap between the water cooling plate and the bottom of the battery cell. The thermal pad meets the thermal management requirements and the battery module is normal.

[0066] Taking the elastic water cooling plate as an example, the thickness of the thermal pad should fill the gap between the water cooling plate and the bottom of the battery cell. Fig.14 The structural schematic diagram of another battery module shown in the figure, based on the tolerance of the bottom of the battery module (±0.4) and the flatness of the water-cooling plate (±0.5), the calculated tolerance is used to determine the limit tolerance of 0.9mm from the bottom of the battery cell to the surface of the water-cooling plate. In addition, the deformation of the bottom of the battery cell under bulging conditions is 0.14mm, the thickness tolerance of the thermal pad is ±0.1mm, and the thickness value of the thermal pad is 1.3mm. From the above parameters, the distance value between the target bulging battery cell and the water-cooling plate in the battery module can be calculated as: 0.9mm+0.14mm+0.1=1.14mm. It can be seen that the original thickness of the thermal pad is greater than the distance value, and it is determined that the thermal pad can fill the gap between the water-cooling plate and the bottom of the battery cell. The thermal pad meets the thermal management requirements and the battery module is normal.

[0067] Method 3: Determine whether the aluminum bar meets the buffering requirements based on the target bulging battery cell. In one embodiment, if the bulging deformation corresponding to the target bulging battery cell is greater than or equal to the anti-bulging structure length of the aluminum bar in the battery module, it can be determined that the bulging analysis result corresponding to the battery module is abnormal. Fig.15 The structural schematic diagram of an aluminum bar shown in the figure shows that the aluminum bar provided in the embodiment of the present invention is provided with an anti-bulging structure, i.e. a buffer arc. The buffer arc can allow a maximum extension of 6.3 mm, and the size of the buffer arc is 4.4 mm when it is not extended. Therefore, the buffer arc of the aluminum bar can absorb the swelling size of the battery cell, and the maximum absorption amount is 6.3-4.4=1.9 mm. Since the maximum deformation of the battery cell ear is 0.787 mm, that is, the swelling deformation amount is less than the maximum absorption amount, it can be determined that the aluminum bar meets the buffering requirements and the battery module is normal.

[0068] In practical applications, the influence of cell bulging force on the cycle life of battery modules can also be analyzed through cell ion flow analysis. Fig.16 A schematic diagram of the internal structure of a battery cell and Fig.17 As shown in the figure, as the number of cycles and the swelling force increase, the electrolyte infiltration is insufficient, the ion concentration decreases, the electrochemical reaction rate decreases, and the electrochemical impedance increases, which affects the battery module life. Fig.18A schematic diagram of a diaphragm hole is shown to determine the effect of the swelling force on the diaphragm hole. Specifically, after the diaphragm is compressed, the diaphragm hole shrinks, the ion channel shrinks, the ion transmission rate decreases, the ohmic impedance increases, and the battery module life is affected.

[0069] For the battery module analysis method provided in the above embodiment, the present invention provides a battery module analysis device, see Fig.19 The schematic diagram of the structure of a battery module analysis device shown in FIG. 1 mainly includes the following parts:

[0070] The swelling force prediction module 1902 is used to predict the target swelling force corresponding to the battery module by using a pre-configured target swelling prediction model;

[0071] A cell determination module 1904 is used to perform swelling simulation on the battery module based on the target swelling force, so as to determine a target swelling cell from the cells included in the battery module;

[0072] The swelling analysis module 1906 is used to determine the swelling analysis result corresponding to the battery module according to the target swelling battery cell.

[0073] The battery module analysis device provided in the embodiment of the present invention can use the target swelling prediction model to predict the target swelling force corresponding to the battery module, thereby performing swelling simulation on the battery module based on the target swelling force to obtain a target swelling cell, and the swelling analysis result can be obtained according to the target swelling cell. Compared with the method of using relevant equipment to measure a large amount of swelling force in the prior art, the embodiment of the present invention can significantly reduce the amount of data required for analyzing the swelling situation in the battery module, and can also significantly improve the analysis efficiency.

[0074] In one embodiment, the above-mentioned device also includes a model building module, which is used to: obtain actual measured swelling data corresponding to the battery module; wherein the actual measured swelling data is obtained by performing a cyclic expansion test on the battery module under a specified environment; and fit the model parameters of the initial swelling model according to the actual measured swelling data to obtain a target swelling prediction model.

[0075] In one embodiment, the swelling force prediction module 1902 is further used to: obtain a specified number of cycles corresponding to the battery module, and predict a target swelling force corresponding to the battery module based on the specified number of cycles using a target swelling prediction model.

[0076] In one embodiment, the battery cell determination module 1904 is also used to: perform swelling simulation on the battery module based on the relative position of each battery cell in the battery module and the target swelling force to obtain the swelling deformation amount corresponding to each battery cell; and determine the target swelling battery cell from the battery cells included in the battery module according to the swelling deformation amount corresponding to each battery cell.

[0077] In one embodiment, the swelling analysis module 1906 is also used to: determine the force applied by the target swelling cell to a specified component in the battery module based on the target swelling force; calculate the ratio of the stress threshold corresponding to the specified component to the force; if the ratio is less than a preset safety factor, determine that the swelling analysis result corresponding to the battery module is an abnormal battery module.

[0078] In one embodiment, the swelling analysis module 1906 is also used to: calculate the distance value between the target swollen battery cell and the water cooling plate in the battery module based on the swelling deformation corresponding to the target swollen battery cell; if the distance value is greater than or equal to the original thickness value of the thermal conductive structure in the battery module, determine that the swelling analysis result corresponding to the battery module is an abnormal battery module; wherein the thermal conductive structure is arranged between the target swollen battery cell and the water cooling plate.

[0079] In one embodiment, the swelling analysis module 1906 is further used to: if the swelling deformation corresponding to the target swelling battery cell is greater than or equal to the anti-swelling structure length of the aluminum bar in the battery module, determine that the swelling analysis result corresponding to the battery module is abnormal.

[0080] The device provided in the embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0081] An embodiment of the present invention provides an electronic device. Specifically, the electronic device includes a processor and a storage device. The storage device stores a computer program, and when the computer program is executed by the processor, it executes the method described in any one of the above-mentioned implementation methods.

[0082] Fig. 20 A structural diagram of an electronic device provided in an embodiment of the present invention, the electronic device 100 includes: a processor 200, a memory 201, a bus 202 and a communication interface 203, wherein the processor 200, the communication interface 203 and the memory 201 are connected via the bus 202; the processor 200 is used to execute an executable module stored in the memory 201, such as a computer program.

[0083] The memory 201 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 203 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0084] The bus 202 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 20 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0085] Among them, the memory 201 is used to store programs, and the processor 200 executes the program after receiving the execution instruction. The method executed by the device for flow process definition disclosed in any embodiment of the above-mentioned embodiment of the present invention can be applied to the processor 200, or implemented by the processor 200.

[0086] The processor 200 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 200. The above processor 200 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present invention can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module may be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 201, and the processor 200 reads the information in the memory 201 and completes the steps of the above method in combination with its hardware.

[0087] The computer program product of the readable storage medium provided in the embodiment of the present invention includes a computer-readable storage medium storing program code, and the instructions included in the program code can be used to execute the methods described in the previous method embodiments. The specific implementation can be referred to the previous method embodiments, which will not be repeated here.

[0088] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0089] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for analyzing a battery module, characterized in that: include: Predicting the target swelling force corresponding to the battery module through the target swelling prediction model; Performing swelling simulation on the battery module based on the target swelling force to determine a target swelling cell from cells included in the battery module; Determining a swelling analysis result corresponding to the battery module according to the target swelling battery cell; Among them, the target swelling prediction model is the cycle number-swelling force prediction model, the target swelling force is the maximum swelling force, the target swelling battery cell is the battery cell with the largest swelling deformation or the battery cell with a specific type of deformation, and the swelling analysis result is whether the specified component is cracked or whether the thermal conductive structure meets the thermal management requirements or whether the aluminum bar meets the buffering requirements.

2. The method according to claim 1, characterized in that Before predicting the target swelling force corresponding to the battery module by the target swelling prediction model, the method further includes: Obtaining actual swelling data corresponding to the battery module; wherein the actual swelling data is obtained by performing a cyclic swelling test on the battery module under a specified environment; The model parameters of the initial swelling model are fitted according to the swelling measured data to obtain a target swelling prediction model.

3. The method according to claim 2, characterized in that The method of predicting the target swelling force corresponding to the battery module by using the target swelling prediction model includes: A specified number of cycles corresponding to the battery module is obtained, and a target swelling force corresponding to the battery module is predicted based on the specified number of cycles by using the target swelling prediction model.

4. The method according to claim 1, characterized in that: The performing swelling simulation on the battery module based on the target swelling force to determine a target swelling cell from cells included in the battery module includes: Based on the relative position of each battery cell in the battery module and the target swelling force, performing swelling simulation on the battery module to obtain the swelling deformation amount corresponding to each battery cell; According to the swelling deformation amount corresponding to each of the battery cells, a target swelling battery cell is determined from the battery cells included in the battery module.

5. The method according to claim 1, characterized in that The step of determining the swelling analysis result corresponding to the battery module according to the target swelling battery cell includes: Determining, according to the target swelling force, a force applied by the target swelling cell to a designated component in the battery module; Calculating a ratio of a stress threshold corresponding to the designated component to the applied force; If the ratio is less than a preset safety factor, it is determined that the swelling analysis result corresponding to the battery module is abnormal.

6. The method according to claim 1, characterized in that The step of determining the swelling analysis result corresponding to the battery module according to the target swelling battery cell further includes: Calculating the distance between the target swollen battery cell and the water cooling plate in the battery module based on the swollen deformation amount corresponding to the target swollen battery cell; If the distance value is greater than or equal to the original thickness value of the heat-conducting structure in the battery module, it is determined that the swelling analysis result corresponding to the battery module is that the battery module is abnormal; wherein the heat-conducting structure is arranged between the target swollen battery cell and the water cooling plate.

7. The method according to claim 1, characterized in that The step of determining the swelling analysis result corresponding to the battery module according to the target swelling battery cell further includes: If the swelling deformation amount corresponding to the target swelling battery cell is greater than or equal to the anti-swelling structure length of the aluminum bar in the battery module, it is determined that the swelling analysis result corresponding to the battery module is abnormal.

8. A battery module analysis device, characterized in that: include: A swelling force prediction module, used to predict the target swelling force corresponding to the battery module through a pre-configured target swelling prediction model; A cell determination module, configured to perform swelling simulation on the battery module based on the target swelling force, so as to determine a target swelling cell from the cells included in the battery module; A swelling analysis module, used to determine a swelling analysis result corresponding to the battery module according to the target swelling battery cell; Among them, the target swelling prediction model is the cycle number-swelling force prediction model, the target swelling force is the maximum swelling force, the target swelling battery cell is the battery cell with the largest swelling deformation or the battery cell with a specific type of deformation, and the swelling analysis result is whether the specified component is cracked or whether the thermal conductive structure meets the thermal management requirements or whether the aluminum bar meets the buffering requirements.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer executable instructions that can be executed by the processor, and the processor executes the computer executable instructions to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method according to any one of claims 1 to 7.

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