Apparatus and method for simulating performance of battery pack based on heat transfer environment migration

Abstract

The application provides a device and method for simulating battery pack performance based on heat transfer environment migration, and relates to the technical field of battery pack performance simulation. The device comprises a wrapping structure, a first compartment, at least two second compartments and a third compartment adjacent to the first compartment, and heat insulation materials between the first compartment and the second and third compartments. The first compartment is used for placing a measured battery cell, and the second and third compartments are provided with auxiliary battery cells. The measured battery cell is a basic unit of a measured battery pack, and the measured battery cell has the same performance as the auxiliary battery cell. The application can accurately simulate the performance of the measured battery pack without actual measurement, and can avoid the problem of poor reference caused by the difference between the laboratory environment and the environment in the battery pack.

Description

Technical Field

[0001] This invention belongs to the field of battery pack performance simulation and prediction technology, and particularly relates to a device and method for simulating battery pack performance based on cell migration of heat transfer environment. Background Technology

[0002] Lithium-ion batteries, as a power source for new energy vehicles, have been widely used in the field due to their green, environmentally friendly, recyclable, and small size characteristics. Testing and evaluating battery performance is a crucial research and development activity during the battery development phase.

[0003] In the laboratory, individual battery cells are typically connected to a charge / discharge cabinet to perform specific charge / discharge cycles, thereby evaluating various performance characteristics of the cells. For example... Figure 1 The diagram shows a typical laboratory test bench setup. The positive and negative terminals of the battery cell are welded with busbars for wiring. The busbars are connected to the charging and discharging cabinet wiring harness by bolts or mechanical tightening. The entire battery cell is placed in an environmental chamber with strong forced convection airflow, which is usually used for testing.

[0004] The testing conditions in the laboratory described above result in significant heat exchange between the tested battery cell and the surrounding environment chamber. These heat transfer pathways include convective heat transfer between the cell surface and the flowing air, heat conduction between the cell and the connecting wiring harness, and heat conduction between the cell and the support frame of the environment chamber. These heat conduction processes mean that the temperature exhibited by the battery cell during various tests is strongly influenced by these factors.

[0005] However, the actual performance of a cell in a pack often differs greatly from laboratory test results. This is because the heat dissipation environment of a cell in a pack is vastly different from the test conditions of a single cell in a laboratory. Consequently, the results of single-cell tests in the laboratory are of poor reliability when used to predict the performance of a pack. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a device and method for simulating battery pack performance based on cell-to-cell thermal environment migration. The method applies the concept of analogical migration to battery packs with identical or similar structures and battery packs with known performance. The temperature rise curves of the highest and lowest temperature cells in the known performance battery pack are used as calibration objects. The cell units in the known performance battery pack are applied to the designed device. Based on the calibration objects, the parameter combinations of the heat transfer devices in the device are calibrated. The calibrated parameter combinations are then applied to the cells of the battery pack under test, thereby simulating the performance of the battery pack and predicting the temperatures of the highest and lowest temperature cells without the need for actual measurement. This also avoids the problem of poor reference accuracy caused by differences between the laboratory environment and the environment in the battery pack.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions: The first aspect of the present invention provides an apparatus for simulating battery pack performance based on cell migration in the heat transfer environment.

[0008] A device for simulating battery pack performance based on cell migration in a heat transfer environment includes a wrapping structure. The wrapping structure has a first compartment and at least two second and third compartments adjacent to the first compartment. Thermal insulation material is provided between the first compartment and the second and third compartments. The first compartment is used to place the cell under test, and auxiliary cells are provided in the second and third compartments. The cell under test and the auxiliary cells are both basic units constituting the battery pack under test.

[0009] As an alternative technical solution, the outer surface of the package structure is provided with a windproof cover.

[0010] As an alternative technical solution, the packaging structure is a wooden board or a metal plate.

[0011] As an alternative technical solution, the thermal insulation material is foam or aerogel.

[0012] As an alternative technical solution, the package structure is also provided with a busbar, which is used to connect adjacent tested cells and auxiliary cells.

[0013] As an alternative technical solution, the packaging structure is a semi-closed structure with an open top, and the first compartment, the second compartment, and the third compartment are all open at the top.

[0014] A second aspect of the present invention provides a method for simulating battery pack performance based on cell migration in the heat transfer environment.

[0015] A method for simulating battery pack performance based on cell-to-cell thermal environment migration includes the following steps: During the charging and discharging process of the No. 1 battery pack, the temperature rise data of the No. 1 cell that makes up the No. 1 battery pack is obtained, and the temperature rise curves of the cell with the highest temperature and the cell with the lowest temperature are selected and labeled as the first temperature rise curve and the second temperature rise curve, respectively. The first cell is placed into the first compartment of the aforementioned device for simulating battery pack performance based on cell migration in the heat transfer environment. The thickness and thermal conductivity of the encasing structural components, and the thickness and thermal conductivity of the insulation material are used as parameters for combination; By adjusting the parameter combination, the temperature distribution of cell No. 1 in the first compartment is made close to the first temperature rise curve under the same current conditions, thus obtaining the first parameter combination; similarly, the temperature distribution of cell No. 1 in the first compartment is made close to the second temperature rise curve, thus obtaining the second parameter combination. The second cell, which makes up the second battery pack, is placed in the first compartment. Under the same current conditions, the first parameter combination and the second parameter combination are applied respectively. The highest and lowest temperatures of the second cell are the simulated highest and lowest temperature cells of the second battery pack.

[0016] As an alternative technical solution, the No. 2 battery pack has the same structure as the No. 1 battery pack.

[0017] As an optional technology, data on cell temperature rise during the cyclic charging and discharging of the No. 1 battery pack is obtained, specifically including: A periodic pulse current is applied to the No. 1 battery pack to make it cycle charge and discharge, with the amount of charge and discharge being equal, and the temperature rise data of the No. 1 cell is measured during this process. When the temperature change rate of cell No. 1 is observed to be less than the set value, the system is considered to have reached a balanced state, and the charging and discharging cycle is stopped.

[0018] As an optional technique, the first parameter combination and the second parameter combination are applied respectively, specifically: The thickness and thermal conductivity of the wrapping structural components and the thickness and thermal conductivity of the insulation material are set according to the first parameter combination and the second parameter combination, respectively.

[0019] The above one or more technical solutions have the following beneficial effects: This invention provides an apparatus and method for simulating battery pack performance based on cell migration in heat transfer environment. It applies the concepts of migration and analogy to battery packs with the same or similar structures but different performance characteristics. The temperature rise curves of the highest and lowest temperature cells in the known performance battery pack are used as calibration objects. The cell units from the known performance battery pack are applied to the designed apparatus. Based on the calibration objects, the parameter combinations of the heat transfer devices in the apparatus are calibrated. These calibrated parameter combinations are then applied to the cells of the unknown performance battery pack, thus simulating the performance of the unknown performance battery pack and predicting the temperatures of the highest and lowest temperature cells without requiring actual measurements. This also avoids the problem of poor reference accuracy caused by differences between the laboratory environment and the environment within the battery pack.

[0020] The device for simulating battery pack performance based on heat transfer environment migration designed in this invention sets up a second compartment and a third compartment adjacent to the first compartment inside the encapsulation structure. Thermal insulation material is installed between the first compartment and both the second and third compartments. During subsequent parameter adjustments, the thickness and thermal conductivity of the encapsulation structure, as well as the thickness and thermal conductivity of the insulation material, are used as parameter combinations. These parameter combinations are then calibrated using calibration objects (temperature rise curves of the highest and lowest temperature battery cells). This process essentially simulates and predicts the performance of battery packs with unknown performance by migrating the similarity of the internal heat transfer environment materials during the temperature rise process for different battery packs with the same or similar structures.

[0021] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 This is a schematic diagram of a battery cell testing bench in the existing technology.

[0024] Figure 2 This is a schematic diagram of the internal structure of a traditional battery pack.

[0025] Figure 3 This is a top cross-sectional view of the device in Embodiment 1.

[0026] Figure 4 This is a schematic diagram of the pack A and pack B structures in Example 2.

[0027] Figure 5This is a schematic diagram showing the locations of the battery cells with the highest and lowest temperatures in Pack A in Example 2.

[0028] Figure 6 This is a flowchart of the method in Example 2.

[0029] Figure 7 A schematic diagram of the periodic pulse current applied to pack A.

[0030] Figure 8 This is a schematic diagram of the temperature results from the cyclic test of pack A under operating conditions.

[0031] 1. Battery cell; 2. Connecting harness; 3. Busbar; 4. Battery pack; 5. Enclosure structure; 6. First compartment; 7. Second compartment; 8. Third compartment; 9. Thermal insulation material; 10. Windproof cover. Detailed Implementation

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0034] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0035] Example 1 Evaluating various cell performance characteristics by subjecting batteries to specific charge and discharge cycles is a crucial method during the development phase. In laboratories, batteries are typically connected directly to a charge / discharge cabinet, which simulates their operation in a vehicle. However, this method of evaluating battery temperature rise under operating conditions has significant drawbacks: Firstly, when the battery is operating in the vehicle, it consists of multiple cells connected in series and parallel, assembled together by structural components and adhesive bonding. The cells do not experience significant heat transfer with surrounding components. Figure 2 As shown, the heat generated by the battery during operation is basically absorbed by the battery body.

[0036] In existing technologies, according to Figure 1 The test device is constructed in such a way that only a portion of the heat generated by the battery during operation is absorbed by the battery, which manifests as a temperature rise in the battery. The other portion of the heat (Q1 positive + Q1 negative + Q2 air + Q3 bracket) is transferred to the outside of the battery through the wiring harness connecting the positive and negative electrodes and environmental convection.

[0037] like Figure 1As shown, the heat transfer process described above can be expressed by the following formula: Qproduction = Qabsorption + (Q1positive + Q1negative + Q2air + Q3support). ΔT = Qabsorbed / (Cp * mcell).

[0038] Therefore, under the same operating conditions, the temperature rise of a battery in a vehicle and the temperature rise of a battery tested in a laboratory are different. The temperature rise of a battery during laboratory testing is much smaller than the temperature rise of a battery when it is actually used in a vehicle. Since battery temperature and performance are strongly correlated, simply using existing test benches in the laboratory to test the temperature rise of the battery cells and then simulating the actual temperature rise of the battery in a vehicle often results in large errors and is not reliable for reference.

[0039] Therefore, accurately evaluating battery performance during the laboratory testing phase has become a pressing issue. To address the shortcomings of traditional test benches in performance testing, this invention comprehensively modifies traditional test benches and discloses a device for simulating battery pack performance based on cell-to-pack performance in the context of thermal environment migration.

[0040] This embodiment aims to improve the traditional test bench so that the test bench for cell temperature rise experiments in the laboratory can fully simulate the heat transfer mode in the battery pack of the whole vehicle, and achieve the purpose of accurately simulating the temperature rise performance of the battery pack during actual operation of the whole vehicle by utilizing the temperature rise of the cells in the laboratory.

[0041] Specifically, such as Figure 3 As shown, an apparatus for simulating battery pack performance based on cell migration in a heat transfer environment includes a wrapping structure 5. The wrapping structure 5 has a first compartment 6 and at least two second compartments 7 and a third compartment 8 adjacent to the first compartment 6. Thermal insulation material 9 is provided between the first compartment 6 and the second and third compartments 8. The first compartment 6 is used to place the battery cell 1 under test, and auxiliary cells are provided in the second and third compartments 7 and 8 respectively. Both the battery cell under test and the auxiliary cells are basic units constituting the battery pack under test, and the battery cell under test and the auxiliary cells have the same performance.

[0042] Furthermore, the outer side of the package structure 5 is provided with a windproof cover 10, which further blocks the heat transfer between the tested battery cell 1 and the air.

[0043] The actual working internal environment of the battery pack is simulated by using the encapsulation structure 5, the heat insulation material 9, and the windproof cover 10. The internal heat transfer environment of the battery pack is simulated by using the tested cell and the adjacent auxiliary cell.

[0044] It can be understood that the technology in this embodiment is similar to... Figure 1 Compared to the existing test benches shown: By setting up the encapsulation structure 5, the heat transfer between the battery cell 1 and the air during the testing process of the existing technology test bench is blocked; By setting up a first compartment 6, a second compartment 7, and a third compartment 8, and setting an auxiliary cell 1 in the second compartment 7 and the third compartment 8, while setting the cell to be tested in the first compartment 6, the heat transfer between the internal cells 1 and between the cell 1 and the outer shell of the battery pack 4 during the actual operation of the vehicle battery pack 4 can be simulated. By eliminating the connection between the positive and negative terminals of battery cell 1 and the busbar via a wiring harness, heat transfer between battery cell 1 and the connecting wiring harness 2 is blocked during testing on existing test benches.

[0045] With the above structure, the device for simulating battery pack performance based on cell migration of heat transfer environment proposed in this embodiment can accurately simulate the working environment of cell 1 in the whole vehicle battery pack 4, thereby providing a theoretical basis for accurately simulating the performance of battery pack 4 through the performance test of cell 1.

[0046] It can be understood that the packaging structure 5 constitutes a semi-closed space that encloses the first compartment 6, the second compartment 7, and the third compartment 8. In this embodiment, the second compartment 7 and the third compartment 8 are provided on both sides of the first compartment 6. In other embodiments, based on the spatial position of the first compartment 6, compartment units can also be provided at the lower, left, right, front, and rear positions of the first compartment 6 for placing the auxiliary battery cell 1.

[0047] The enclosure structure 5 is a semi-closed space with a closed bottom and four sides and an open top. This design facilitates the placement of the tested battery cell and auxiliary battery cell. Combined with the wind shield 10, it can also simulate the heat transfer of the operating environment inside the battery pack 4.

[0048] In this embodiment, both the tested cell 1 and the auxiliary cell are basic units constituting the tested battery pack 4. The performance of the tested battery pack 4 is accurately simulated by testing the performance of the tested cell 1. It can be understood that the auxiliary cell 1 mentioned in this embodiment refers to another cell 1 with the same performance as the tested cell 1, used to simulate the heat transfer environment of the tested cell 1 within the tested battery pack 4. Therefore, in this embodiment, by using the relative spatial positions of the tested cell 1 and the auxiliary cell 1, the heat transfer environment between the cells 1 within the tested battery pack 4 can be fully simulated, achieving accurate simulation of the battery pack 4's performance.

[0049] It can be understood that a busbar 3 is also provided inside the package structure 5. The busbar 3 is used to connect the adjacent tested battery cell 1 and the auxiliary battery cell 1. Compared with the prior art, the busbar 3 in this embodiment is located inside the package structure 5, rather than outside the battery cell 1. Combined with the setting of the wind shield 10, it can block the heat transfer between the battery cell 1 and the connecting wire harness 2.

[0050] In this embodiment, the wrapping structure 5 is a wooden board or a metal plate, and the thermal insulation material 9 is foam or aerogel. In other embodiments, other materials may also be used.

[0051] Work process: Test benches for simulating pack performance at the cell level, such as Figure 3 As shown, the tested cell 2 is placed between two auxiliary cells 1 and 3, connected by a busbar. This arrangement aims to simulate the heat dissipation environment of cell 1 inside the pack as closely as possible. Thermal insulation material 9, which can be foam or aerogel, is filled between the cells 1. This small module is surrounded by structural components to simulate the crossbeams and module end plates inside the battery pack; these components can be made of wood, aluminum, etc. Additionally, a windproof shroud 10 is added to the outside of the entire test sample to isolate the sample from heat transfer caused by airflow inside the test chamber.

[0052] Example 2 This embodiment discloses a method for simulating battery pack performance based on cell migration in the heat transfer environment.

[0053] A method for simulating battery pack performance based on cell-to-cell thermal environment migration includes the following steps: During the charging and discharging process of the No. 1 battery pack, the temperature rise data of the No. 1 cell that makes up the No. 1 battery pack is obtained, and the temperature rise curves of the cell with the highest temperature and the cell with the lowest temperature are selected and labeled as the first temperature rise curve and the second temperature rise curve, respectively. The first cell is placed into the first compartment of the aforementioned device for simulating battery pack performance based on cell migration in the heat transfer environment. The thickness and thermal conductivity of the encasing structural components, and the thickness and thermal conductivity of the insulation material are used as parameters for combination; By adjusting the parameter combination, the temperature distribution of cell No. 1 in the first compartment is made close to the first temperature rise curve under the same current conditions, thus obtaining the first parameter combination; similarly, the temperature distribution of cell No. 1 in the first compartment is made close to the second temperature rise curve, thus obtaining the second parameter combination. The second cell, which makes up the second battery pack, is placed in the first compartment. Under the same current conditions, the first parameter combination and the second parameter combination are applied respectively. The highest and lowest temperatures of the second cell are the simulated highest and lowest temperature cells of the second battery pack.

[0054] The method described in this embodiment employs a transfer or analogy approach, assuming that battery packs with similar or identical structures exhibit similar heat transfer methods during cell temperature rise, and that the energy transfer methods and total amount of heat transfer within the cells are the same. Therefore, by using temperature rise data from cells in a known-performance battery pack to calibrate environmental factors within that battery pack, the calibration results are considered equally applicable to battery packs with unknown performance. Subsequently, when studying any battery pack with unknown performance, it is unnecessary to actually construct the actual unknown-performance battery pack structure. Instead, based solely on the aforementioned calibration results, the calibration results (i.e., environmental factors within the battery pack) are applied to the cell units of the unknown-performance battery pack. Performance testing of the cell units constituting the unknown-performance battery pack allows for reasonable prediction and simulation of the overall performance of the unknown-performance battery pack.

[0055] The battery pack with known performance mentioned above is battery pack number one, and the battery pack with unknown performance is battery pack number two.

[0056] The aforementioned environmental factors are related to the structure within the battery pack. Based on the device for simulating battery pack performance based on heat transfer environment migration in the aforementioned embodiment 1, the environmental factors considered in this embodiment are mainly located on the thickness and thermal conductivity of the encapsulation structure and the thickness and thermal conductivity of the insulation material.

[0057] It can be understood that, in order to perform the simulation more accurately, the No. 2 battery pack and the No. 1 battery pack described in this embodiment have the same or similar structures.

[0058] Furthermore, data on the temperature rise of the battery cells during the cyclic charging and discharging of the No. 1 battery pack were obtained, specifically including: A periodic pulse current is applied to the No. 1 battery pack to make it cycle charge and discharge, with the amount of charge and discharge being equal, and the temperature rise data of the No. 1 cell is measured during this process. When the temperature change rate of cell No. 1 is observed to be less than the set value, the system is considered to have reached a balanced state, and the charging and discharging cycle is stopped.

[0059] Furthermore, the first parameter combination and the second parameter combination are applied respectively, specifically as follows: The thickness and thermal conductivity of the wrapping structural components and the thickness and thermal conductivity of the insulation material are set according to the first parameter combination and the second parameter combination, respectively.

[0060] To better illustrate the technical solution of this embodiment, the following explanation will be provided in conjunction with the accompanying drawings. In the following description, for ease of description, battery pack A and battery pack B will be labeled as Pack A and Pack B, respectively. The battery cell in Pack A is referred to as cell A, and the battery cell in Pack B is referred to as cell B.

[0061] Pack A and pack B have similar structures, such as Figure 4 As shown, both are CTP structures, with the cells directly bonded to the base plate using structural components. The cells are connected in series using busbars. The positions of the cells with the highest and lowest temperatures in Pack A are shown below. Figure 5 As shown, the highest temperature generally occurs at the geometric center of the pack because heat exchange with surrounding components is generally more difficult there, while the lowest temperature generally occurs at the edge of the pack because heat exchange with surrounding components is generally easier there.

[0062] like Figure 6 As shown, battery pack A with existing test data is selected. The test conditions for pack A are as follows: With an ambient temperature of 25℃ and an initial SOC of 50% for the pack, a periodic pulse current condition is applied to the pack, specifically a 5C charging rate for 10 seconds followed by a 5C discharging rate for 10 seconds. Figure 7 As shown, this cycle repeats, with the amount of charge and discharge equal, ensuring that the SOC of the pack fluctuates within a small range during the test, thus avoiding uncontrolled test temperatures caused by changes in SOC.

[0063] The final test results for Pack A are as follows: Figure 8 As shown, under periodic pulse conditions, the heat generation of the battery and the heat exchange of the surrounding system reach equilibrium, and the temperature eventually balances to a specific temperature. In the experiment, when the observed temperature change rate of the battery cell is less than 0.5℃ / 30min, the system is considered to have reached equilibrium. The temperature rise data and temperature rise curves (i.e., the first temperature rise curve and the second temperature rise curve) of the two batteries with the highest and lowest final temperatures in Pack A are selected.

[0064] Using the highest and lowest temperature cells measured in the above pack A test conditions as calibration objects, according to Example 1... Figure 3 As shown, a benchmark test bench at the Cell A level was constructed. In this embodiment, foam was selected as the insulation material, and wood was selected as the material for the structural components. The thickness and thermal conductivity of the foam and wood were used as parameter combinations. The parameter combinations were adjusted until, under the same current conditions, the performance in Embodiment 1 was achieved. Figure 3 In the device shown, the temperature rise curve of cell A is infinitely close to the temperature rise curves of the two cells with the highest and lowest final temperatures in Pack A, thus obtaining two sets of parameter combinations, namely the first parameter combination and the second parameter combination.

[0065] The final calibrated parameters are shown in Table 1: Table 1. Parameter Results of Cell A vs. Pack A

[0066] Thus, we have derived the parameter combinations for the thermal insulation material and encapsulation components of the test bench under the two simulated cell conditions of highest and lowest temperature in pack A. Applying this parameter combination to cell B allows us to predict the temperatures of the cells with the highest and lowest temperatures in pack B, thereby enabling us to scientifically and rationally infer the performance of pack B from the test data of cell B.

[0067] This embodiment applies the concepts of transfer and analogy to battery packs with unknown or known performance that have the same or similar structures. The temperature rise curves of the highest and lowest temperature cells in the known performance battery pack are used as calibration objects. Based on these calibration objects and the cells of the known performance battery pack, the parameter combinations of the heat transfer device are calibrated. These calibrated parameter combinations are then applied to the cells of the unknown performance battery pack, thus simulating the performance of the unknown performance battery pack and predicting the temperatures of the highest and lowest temperature cells without requiring actual measurements. This also avoids the problem of poor reference accuracy caused by differences between the laboratory environment and the environment within the battery pack.

[0068] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A device for simulating battery pack performance based on cell-to-pack thermal environment migration, characterized in that, The device includes a packaging structure, which has a first compartment and at least two second and third compartments adjacent to the first compartment. Thermal insulation material is provided between the first compartment and each of the second and third compartments. The first compartment is used to hold the battery cell under test, and auxiliary battery cells are provided in the second and third compartments. Both the battery cell under test and the auxiliary battery cells are basic units constituting the battery pack under test. The outer surface of the packaging structure is provided with a windproof cover; the packaging structure is made of wood or metal; a busbar is also provided inside the packaging structure, which is used to connect adjacent tested cells and auxiliary cells; the packaging structure is a semi-closed structure with an open top, and the tops of the first compartment, the second compartment and the third compartment are open. The insulation material is foam or aerogel.

2. A method for simulating battery pack performance based on cell-to-cell thermal environment migration, characterized in that, Includes the following steps: During the charging and discharging process of the No. 1 battery pack, the temperature rise data of the No. 1 cell that makes up the No. 1 battery pack is obtained, and the temperature rise curves of the cell with the highest temperature and the cell with the lowest temperature are selected and labeled as the first temperature rise curve and the second temperature rise curve, respectively. The first cell is placed into the first compartment of the device for simulating battery pack performance based on cell migration as described in claim 1. The thickness and thermal conductivity of the encasing structural components, and the thickness and thermal conductivity of the insulation material are used as parameters for combination; By adjusting the parameter combination, the temperature distribution of cell No. 1 in the first compartment is made close to the first temperature rise curve under the same current conditions, thus obtaining the first parameter combination. Similarly, by making the temperature distribution of cell No. 1 within the first compartment close to the second temperature rise curve, a second parameter combination is obtained; The second cell, which makes up the second battery pack, is placed in the first compartment. Under the same current conditions, the first parameter combination and the second parameter combination are applied respectively. The highest and lowest temperatures of the second cell are the simulated highest and lowest temperature cells of the second battery pack.

3. The method for simulating battery pack performance based on cell migration according to claim 2, characterized in that, The No. 2 battery pack has the same structure as the No. 1 battery pack.

4. The method for simulating battery pack performance based on cell migration according to claim 2, characterized in that, Obtain cell temperature rise data during the cyclic charging and discharging process of the No. 1 battery pack, specifically including: A periodic pulse current is applied to the No. 1 battery pack to make it cycle charge and discharge, with the amount of charge and discharge being equal, and the temperature rise data of the No. 1 cell is measured during this process. When the temperature change rate of cell No. 1 is observed to be less than the set value, the system is considered to have reached a balanced state, and the charging and discharging cycle is stopped.

5. The method for simulating battery pack performance based on cell-to-pack thermal environment migration as described in claim 2, characterized in that, Apply the first parameter combination and the second parameter combination respectively, specifically as follows: The thickness and thermal conductivity of the wrapping structural components and the thickness and thermal conductivity of the insulation material are set according to the first parameter combination and the second parameter combination, respectively.

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