Lithium battery connecting piece current-carrying capacity calculation and verification method and system

Abstract

The invention relates to a method and system for calculating and verifying the current-carrying capacity of a lithium battery connecting piece, and belongs to the technical field of batteries. The method for calculating and verifying the current-carrying capacity of the lithium battery connecting piece comprises the steps that mathematical models for current-carrying calculation of uniform-cross-section and variable-cross-section battery connecting pieces are constructed; and finally, equivalently calculating current-carrying values of the uniform-cross-section and variable-cross-section battery connecting pieces by quoting efficiency. The parameter acquisition comprises the steps of measuring the initial temperature of a plurality of single battery connecting pieces and the internal gas temperature of the battery, and determining the initial temperature of the battery connecting pieces and the temperature range of the internal gas temperature of the battery according to a test result. The initial temperature of the connecting piece and the internal gas temperature of the battery are used for calculating transfer heat and heat exchange heat of the connecting piece. Theoretical reference is provided for design of the connecting piece, the battery structure design efficiency and calculation accuracy are improved, consumption of simulation resources and test resources is effectively reduced, and the design cost is reduced.

Description

Technical Field

[0001] The present disclosure belongs to the field of battery technology, and in particular relates to a method and system for calculating and verifying the current-carrying capacity of a lithium battery connector. Background Art

[0002] In the battery structure design, the connecting piece acts as a bridge and is a key structural component connecting the cover plate pole and the battery cell tab. It not only reduces the probability of the tab folding inward and reduces the risk of internal short circuit, but also serves as an important conductor to realize the circulation of the entire battery circuit.

[0003] The current-carrying capacity of the connector is a key factor in battery safety. Existing battery cell design technology mitigates the risk of thermal runaway caused by a battery short circuit by reducing the local cross-sectional area of the connector to prevent it from melting in the event of a short circuit. However, this reduction in the local cross-sectional area of the connector results in insufficient current carrying capacity.

[0004] If the connector has a low current capacity, the temperature will be higher than the cell temperature during high-current charging and discharging. This heat will then be transferred to the interior of the cell, causing a sharp increase in cell temperature and leading to the risk of thermal runaway in the lithium-ion battery. Therefore, accurately assessing the current-carrying capacity of battery connectors is crucial to battery safety.

[0005] Currently, the current-carrying capacity of connectors is generally calculated using 3-5A / mm2 for aluminum and 5-8A / mm2 for copper. This calculation method is based on the experience of wires in the electrician's manual. However, the shape of the wire and the shape of the connector are completely different, and the calculation results for different cross-sectional areas of different shapes of connectors are also different. Therefore, this calculation method cannot accurately evaluate the current-carrying capacity of the connector.

[0006] Therefore, it is necessary to provide a new method and system for calculating and verifying the current carrying capacity of lithium battery connectors to solve the above technical problems. Summary of the Invention

[0007] The purpose of the present disclosure is to provide a method and system for calculating and verifying the current carrying capacity of a lithium battery connector in order to solve the above problems.

[0008] The present disclosure achieves the above objectives through the following technical solutions: A method for calculating and verifying the current carrying capacity of a lithium battery connector includes the following steps: Construct mathematical models for calculating current carrying capacity of connectors with uniform cross-section and connectors with variable cross-section; Based on the mathematical model for calculating the current carrying capacity of the uniform cross-section connecting piece and the mathematical model for calculating the current carrying capacity of the variable cross-section connecting piece, efficiency is introduced to construct an equivalent calculation model for the current carrying capacity of battery connecting pieces with different cross-section shapes; Setting a single battery temperature sensing test rule, and obtaining the numerical range of the temperature parameter in the current carrying equivalent calculation model of the battery connectors with different cross-sectional shapes through the temperature sensing test; A temperature parameter is selected within the numerical range of the temperature parameter and substituted into the current-carrying equivalent calculation model of battery connectors with different cross-sectional shapes to perform calculations and verify the accuracy of the model.

[0009] As a further optimization solution of the present disclosure, the mathematical model for calculating the current carrying capacity of the uniform cross-section connecting piece is expressed as follows: ; Where λ is the thermal conductivity; h is the surface heat transfer coefficient; S is the calculated cross-sectional area of the structural component; A s is the calculated surface area of the structural member; L is the calculated length of the structural member; ρ T is the resistivity of the material at the allowable temperature; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the difference between the internal temperature of the battery cell and the allowable temperature of the surface of the structural part.

[0010] As a further optimization solution of the present disclosure, the expression of the mathematical model for calculating the current carrying capacity of the variable cross-section connecting piece is as follows: ; Where λ is the thermal conductivity; h is the surface heat transfer coefficient; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the allowable temperature difference between the internal temperature of the battery cell and the surface of the structural part, R T总 is the total resistance of the connecting piece, and the total resistance and the partial resistance are divided into series and parallel. S(x) is the cross-sectional area as a function of x, and P(x) is the perimeter as a function of x. x1 is the starting point for calculating the length of the connecting piece; x2 is the end point for calculating the length of the connecting piece.

[0011] As a further optimization solution of the present disclosure, the expression of the equivalent calculation model of the current carrying capacity of the battery connecting pieces with different cross-sectional shapes is as follows: ; Where η is efficiency; λ is thermal conductivity; h is surface heat transfer coefficient; S is the calculated cross-sectional area of the structural component; A s is the calculated surface area of the structural member; L is the calculated length of the structural member; ρ 20 is the resistivity of the material at 20°C; α is the conductor temperature coefficient; T is the allowable surface temperature of the structural part; ΔT1 is the allowable surface temperature rise of the structural part; ΔT2 is the allowable temperature difference between the internal temperature of the battery cell and the surface temperature of the structural part.

[0012] As a further optimization solution of the present disclosure, setting the single cell temperature sensing test rules includes: Set up temperature sensing test methods, test samples and test equipment; The temperature sensing test method includes a unified charging and discharging method, a battery built-in temperature sensing wire wiring method and the same measurement point; The test samples include lithium batteries of different capacities; The test equipment includes a data recording instrument, a power supply, a test cabinet and a temperature sensing line.

[0013] As a further optimization solution of the present disclosure, batteries with connecting pieces of different shapes and cross-sections were selected for verification, and the measured current-carrying results, simulation results, and calculation results of the battery connecting pieces were compared.

[0014] A lithium battery connector current carrying capacity calculation and verification system, comprising: A model building module, used to build a mathematical model for calculating the current carrying capacity of a uniform cross-section connector and a mathematical model for calculating the current carrying capacity of a variable cross-section connector; An equivalent model construction module is used to introduce efficiency to construct an equivalent calculation model for the current carrying capacity of battery connectors with different cross-sectional shapes based on the mathematical model for calculating the current carrying capacity of the uniform cross-sectional connector and the mathematical model for calculating the current carrying capacity of the variable cross-sectional connector; A test setting module is used to set the temperature sensing test rules of the single battery and obtain the numerical range of the temperature parameter in the current carrying equivalent calculation model of the battery connecting pieces with different cross-sectional shapes through the temperature sensing test; The verification module is used to select a temperature parameter within the value range of the temperature parameter and substitute it into the current-carrying equivalent calculation model of battery connectors with different cross-sectional shapes to perform calculation and verify the accuracy of the model.

[0015] As a further optimization solution of the present disclosure, the test setting module sets the single cell temperature sensing test rules including: Set up temperature sensing test methods, test samples and test equipment; The temperature sensing test method includes a unified charging and discharging method, a battery built-in temperature sensing wire wiring method and the same measurement point; The test samples include lithium batteries of different capacities; The test equipment includes a data recording instrument, a power supply, a test cabinet and a temperature sensing line.

[0016] An electronic device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory for storing computer programs; The processor is used to execute the program stored in the memory to implement the method for calculating and verifying the current carrying capacity of the lithium battery connecting piece.

[0017] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements a method for calculating and verifying the current-carrying capacity of a lithium battery connector.

[0018] The beneficial effects of the present disclosure are: This disclosure provides a theoretical reference for the design of connecting pieces, improves the efficiency and calculation accuracy of battery structure design, effectively reduces simulation and testing resources, and reduces design costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of a method provided in an embodiment of the present disclosure; Figure 2 is a schematic diagram of a connecting piece with a uniform cross-section provided in an embodiment of the present disclosure; Figure 3 A simplified calculation diagram of a uniform cross-section connecting piece provided in an embodiment of the present disclosure; Figure 4 A schematic diagram of a variable cross-section connecting piece provided in an embodiment of the present disclosure; Figure 5 A schematic diagram of a variable cross-section connecting piece microelement provided in an embodiment of the present disclosure; Figure 6 A simplified calculation diagram of a variable cross-section connecting piece provided in an embodiment of the present disclosure; Figure 7 A schematic diagram of temperature test points provided in an embodiment of the present disclosure; Figure 8 This is a temperature test wiring diagram provided in an embodiment of the present disclosure; Figure 9 Provides a comparison of calculation, simulation, and measured results for nine battery cell positive electrode connectors of different shapes in the embodiments of the present disclosure; Figure 10 Provides a comparison of calculation, simulation, and measured results for nine battery cell negative electrode connectors of different shapes in the embodiments of the present disclosure; Figure 11 A block diagram of the system structure provided in an embodiment of the present disclosure; Figure 12 This is a block diagram of the device structure provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] The present application will be described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0021] like Figure 1 As shown, a method for calculating and verifying the current carrying capacity of a lithium battery connector includes the following steps: S1. Constructing mathematical models for calculating the current carrying capacity of connectors with uniform cross-sections and connectors with variable cross-sections, specifically including: The state of the equal-section battery connector inside the battery is described as follows Figure 2 :When the battery capacity is less than 30% SOC, the initial temperature of the connecting piece is t0. At a certain stage of charge and discharge, the temperature of the connecting piece is t c At this moment, the internal gas temperature of the battery is t f The physical model of the connecting piece is simplified under the assumption that the connecting piece is a one-dimensional heat conduction problem in the temperature field and is a steady-state process, and the thermal conductivity coefficient is a constant. After simplification, Figure 3 shown.

[0022] Figure 3 The physical model of the uniform cross-section battery connector is simplified into a thermal resistance calculation model, where the heat dissipation of the connector can be calculated using the formula as follows: ; ; The heat input to the connecting piece is: ; in, , , According to the law of conservation of energy, the heat input is equal to the heat dissipated, and the mathematical model expression of the current carrying capacity of the connecting piece can be derived as follows: ; Where λ is the thermal conductivity; h is the surface heat transfer coefficient; S is the calculated cross-sectional area of the structural component; A s is the calculated surface area of the structural member; L is the calculated length of the structural member; ρ T is the resistivity of the material at the allowable temperature; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the allowable temperature difference between the internal temperature of the battery cell and the surface of the structural part. In the calculation model, the allowable temperature difference ΔT1 on the surface of the structural part is the difference between the initial temperature t0 of the connecting piece when the battery power is less than 30% SOC and the maximum allowable temperature t c The temperature difference between the internal temperature of the battery cell and the surface temperature of the structural parts in the calculation model is the maximum allowable temperature of the connecting piece when the battery is powered on. c The internal gas temperature of the battery at this moment is t f The temperature difference between.

[0023] Figure 4 Schematic diagram of variable cross-section battery connector, which is different from the internal state of the battery Figure 2 Consistent, and assuming consistency, take the infinitesimal element of the connected piece, such as Figure 5 As shown. The heat dissipation of the connecting piece is Q 传热 +Q换热 , where Q 传热 is the heat transferred between the connecting piece and the adjacent structural parts, Q 换热 is the heat exchange between the connecting plate and the internal gas. According to Fourier's law, we know that: ; After separating the variables, the expression is as follows: ; After integrating both sides, the heat dissipation by conduction is: ; Similarly, according to Newton's cooling formula , after separating the variables we get: ; After integrating both sides, the convective heat transfer heat is: ; The heat input to the connecting piece is: ; According to the law of conservation of energy, the heat input is equal to the heat dissipated, and the mathematical model expression of the current carrying capacity of the connecting piece can be derived as follows:

[0024] Where λ is the thermal conductivity; h is the surface heat transfer coefficient; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the allowable temperature difference between the internal temperature of the battery cell and the surface of the structural part, R T总 is the total resistance of the connecting piece, and the total resistance and the partial resistance are divided into series and parallel; S(x) is the cross-sectional area as a function of x, and P(x) is the perimeter as a function of x; x1 is the starting point for calculating the length of the connecting piece; x2 is the end point for calculating the length of the connecting piece. The allowable temperature difference ΔT1 on the surface of the structural part in the calculation model is the difference between the initial temperature t0 of the connecting piece when the battery power is less than 30% SOC and the maximum allowable temperature t c The temperature difference between the internal temperature of the battery cell and the surface temperature of the structural parts in the calculation model is the maximum allowable temperature of the connecting piece when the battery is powered on. c The internal gas temperature of the battery at this moment is t f The temperature difference between.

[0025] S2. Based on the mathematical model for calculating the current carrying capacity of the uniform cross-section connecting piece and the mathematical model for calculating the current carrying capacity of the variable cross-section connecting piece, efficiency is introduced to construct an equivalent calculation model for the current carrying capacity of battery connecting pieces with different cross-section shapes, specifically including: Use the equivalent calculation method to calculate the equal-section and variable-section battery cell connectors. Figure 4 The shape of the connecting piece is transformed, keeping the corresponding size unchanged, such as Figure 6 shown.

[0026] The variable cross-section connecting piece is divided into two regions, C1 and C2. The C1 region is preferably used for calculation. The calculation formula for the C1 region can use the constant cross-section connecting piece. The current carrying value calculated by the formula is: ; Among them, S C1 is the calculated cross-sectional area of region C1, A sC1 is the calculated surface area on region C1.

[0027] The C2 area is regarded as an extra area on the C1 area. In order to calculate the heat dissipation of the extra area, the efficiency η is introduced for correction.

[0028] The calculation method of the efficiency η is: ; according to Figure 6 , the use area is C1, the effective area is C1+C2, so the efficiency , from which the current carrying value of the entire connecting piece can be obtained as follows: ; Where η is efficiency; λ is thermal conductivity; h is surface heat transfer coefficient; S C1 is the calculated cross-sectional area of region C1; A sC1 is the calculated surface area of region C1; A sC2 is the calculated surface area of region C2; L is the calculated length of the structural member; ρ 20 is the resistivity of the material at 20°C; α is the conductor temperature coefficient; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the allowable temperature difference between the internal temperature of the battery cell and the surface of the structural part.

[0029] S3. Setting a single cell temperature sensing test rule, and obtaining the numerical range of the temperature parameter in the current-carrying equivalent calculation model of the battery connectors with different cross-sectional shapes through the temperature sensing test, specifically including: In order to obtain the temperature parameters of the connecting piece and the temperature parameters of the gas inside the battery in the equivalent calculation formula, a temperature sensing test is performed on the battery. The temperature sensing test includes a charge and discharge method, a battery built-in temperature sensing line wiring method, a test sample, and a test device. The battery built-in temperature sensing points, wiring method, test sample, and test device are as follows: Figure 7 、 Figure 8 shown.

[0030] Figure 7In the figure, 1# is the center of the weld between the positive electrode connector and the battery post, 2# is the point where the cross-sectional area of the positive electrode connector changes, 3# is the gap inside the battery, 4# is the weld between the negative electrode connector and the battery post, and 5# is the point where the cross-sectional area of the negative electrode connector changes. The battery cell test samples include lithium batteries of different capacities, preferably at least 10 different capacities. The number of test samples of the same capacity is at least 3.

[0031] Figure 8 To test the sample and the test equipment, the wiring is done. The test equipment includes several temperature sensing wires. One side of the temperature sensing wires is placed inside the test sample and leads out from the test sample cover. The sample cover must be guaranteed not to leak air. The other side of the temperature sensing wires is connected to the data recording instrument. During the wiring process, it must be ensured that the temperature sensing wires of the data recording instrument correspond one to one with the temperature sensing wires inside the battery cell.

[0032] The charging and discharging method of lithium batteries should be designed according to actual needs. Taking the discharge of lithium batteries as an example, charge at the nominal rate with constant current and constant voltage, leave it for a period of time, discharge at the required rate with constant current to the lower limit voltage, leave it for a period of time, and then charge and discharge in sequence to the maximum required rate.

[0033] S4. Selecting a temperature parameter within its numerical range and substituting it into the current-carrying equivalent calculation model for battery connectors with different cross-sectional shapes to perform calculations and verify the accuracy of the model, specifically including: To verify the feasibility and accuracy of the calculation model, nine batteries with connectors of different shapes and cross-sections were selected, and the measured current-carrying results of the battery connectors, the simulation results, and the calculation results were compared.

[0034] Exemplary, such as Figure 9 The comparison of the measured results, simulation results and calculated results of 9 battery positive electrode connectors shows that the calculated results are comparable to the measured results and are more accurate than the simulation results. Figure 10 The comparison of the measured results, simulation results and calculation results of 9 battery negative electrode connectors shows that the calculated results are comparable to the measured results and are more accurate than the simulation results. This shows that the calculation model can accurately predict the current-carrying capacity of the battery connector.

[0035] like Figure 11 As shown, an embodiment of the present disclosure provides a lithium battery connector current carrying capacity calculation and verification system, including: A model building module, used to build a mathematical model for calculating the current carrying capacity of a uniform cross-section connector and a mathematical model for calculating the current carrying capacity of a variable cross-section connector; An equivalent model construction module is used to introduce efficiency to construct an equivalent calculation model for the current carrying capacity of battery connectors with different cross-sectional shapes based on the mathematical model for calculating the current carrying capacity of the uniform cross-sectional connector and the mathematical model for calculating the current carrying capacity of the variable cross-sectional connector; A test setting module is used to set the temperature sensing test rules of the single battery and obtain the numerical range of the temperature parameter in the current carrying equivalent calculation model of the battery connecting pieces with different cross-sectional shapes through the temperature sensing test; The verification module is used to select a temperature parameter within the value range of the temperature parameter and substitute it into the current-carrying equivalent calculation model of battery connectors with different cross-sectional shapes to perform calculation and verify the accuracy of the model.

[0036] The implementation process of the functions and effects of each module in the above system is specifically described in the implementation process of the corresponding steps in the above method, which will not be repeated here.

[0037] For the system embodiment, since it basically corresponds to the method embodiment, the relevant parts can be referred to the partial description of the method embodiment. The system embodiment described above is only schematic, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the disclosed solution. Those of ordinary skill in the art can understand and implement it without paying any creative work.

[0038] In the above embodiments, any number of all modules can be combined into one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functionality of one or more of these modules can be combined with at least part of the functionality of other modules and implemented in one module. At least one of all modules can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application-specific integrated circuit (ASIC), or can be implemented in hardware or firmware by any other reasonable means of integrating or packaging the circuit, or can be implemented in any one of the three implementation methods of software, hardware, and firmware, or in an appropriate combination of any of them. Alternatively, at least one of all modules can be at least partially implemented as a computer program module, which can perform the corresponding function when the computer program module is executed.

[0039] See also Figure 12 The electronic device provided by an embodiment of the present disclosure includes a processor 1110, a communication interface 1120, a memory 1130 and a communication bus 1140, wherein the processor 1110, the communication interface 1120, and the memory 1130 communicate with each other through the communication bus 1140; Memory 1130, for storing computer programs; The processor 1110 is configured to implement the following method for calculating and verifying the current carrying capacity of a lithium battery connector when executing the program stored in the memory 1130 .

[0040] The communication bus 1140 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus 1140 can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, the figure shows only one thick line, but this does not mean that there is only one bus or only one type of bus.

[0041] The communication interface 1120 is used for communication between the electronic device and other devices.

[0042] The memory 1130 may include a random access memory (RAM) or a non-volatile memory, such as at least one disk storage. Alternatively, the memory 1130 may be at least one storage device located away from the processor 1110.

[0043] The above-mentioned processor 1110 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 gate or transistor logic devices, discrete hardware components.

[0044] The embodiments of the present disclosure further provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for calculating and verifying the current-carrying capacity of a lithium battery connector.

[0045] The computer-readable storage medium may be included in the device / apparatus described in the above embodiments, or may exist independently and not incorporated into the device / apparatus. The computer-readable storage medium carries one or more programs that, when executed, implement the method for calculating and verifying the current-carrying capacity of a lithium battery connector according to the embodiments of the present disclosure.

[0046] According to embodiments of the present disclosure, a computer-readable storage medium may be a non-volatile computer-readable storage medium, such as, but not limited to, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0047] The above embodiments merely illustrate several implementation methods of the present disclosure, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present disclosure. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure.

Claims

1. A method for calculating and verifying the current carrying capacity of a lithium battery connector, characterized in that: The following steps are involved: Construct mathematical models for calculating current carrying capacity of connectors with uniform cross-section and connectors with variable cross-section; Based on the mathematical model for calculating the current carrying capacity of the uniform cross-section connecting piece and the mathematical model for calculating the current carrying capacity of the variable cross-section connecting piece, efficiency is introduced to construct an equivalent calculation model for the current carrying capacity of battery connecting pieces with different cross-section shapes; Setting a single battery temperature sensing test rule, and obtaining the numerical range of the temperature parameter in the current carrying equivalent calculation model of the battery connectors with different cross-sectional shapes through the temperature sensing test; A temperature parameter is selected within the numerical range of the temperature parameter and substituted into the current-carrying equivalent calculation model of battery connectors with different cross-sectional shapes to perform calculations and verify the accuracy of the model.

2. A method for calculating and verifying the current carrying capacity of a lithium battery connector according to claim 1, characterized in that: The mathematical model for calculating the current carrying capacity of the uniform cross-section connecting piece is expressed as follows: ； Where λ is the thermal conductivity; h is the surface heat transfer coefficient; S is the calculated cross-sectional area of the structural component; A s is the calculated surface area of the structural member; L is the calculated length of the structural member; ρ T is the resistivity of the material at the allowable temperature; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the difference between the internal temperature of the battery cell and the allowable temperature of the surface of the structural part.

3. The method for calculating and verifying the current carrying capacity of a lithium battery connector according to claim 1, wherein: The mathematical model for calculating the current carrying capacity of the variable cross-section connecting piece is expressed as follows: ； Where λ is the thermal conductivity; h is the surface heat transfer coefficient; ΔT1 is the allowable temperature rise on the surface of the structural part; ΔT2 is the allowable temperature difference between the internal temperature of the battery cell and the surface of the structural part, R T总 is the total resistance of the connecting piece, and the total resistance and the partial resistance are divided into series and parallel. S(x) is the cross-sectional area as a function of x, and P(x) is the perimeter as a function of x. x1 is the starting point for calculating the length of the connecting piece; x2 is the end point for calculating the length of the connecting piece.

4. The method for calculating and verifying the current carrying capacity of a lithium battery connector according to claim 1, wherein: The equivalent calculation model for the current carrying capacity of battery connectors with different cross-sectional shapes is expressed as follows: Where η is efficiency; λ is thermal conductivity; h is surface heat transfer coefficient; S is the calculated cross-sectional area of the structural component; A s is the calculated surface area of the structural member; L is the calculated length of the structural member; ρ 20 is the resistivity of the material at 20°C; α is the conductor temperature coefficient; T is the allowable surface temperature of the structural part; ΔT1 is the allowable surface temperature rise of the structural part; ΔT2 is the difference between the internal temperature of the battery cell and the allowable surface temperature of the structural part.

5. The method for calculating and verifying the current carrying capacity of a lithium battery connector according to claim 1, wherein: Setting the single cell temperature test rules includes: Set up temperature sensing test methods, test samples and test equipment; The temperature sensing test method includes a unified charging and discharging method, a battery built-in temperature sensing wire wiring method and the same measurement point; The test samples include lithium batteries of different capacities; The test equipment includes a data recording instrument, a power supply, a test cabinet and a temperature sensing line.

6. The method for calculating and verifying the current carrying capacity of a lithium battery connector according to claim 1, wherein: During the verification, batteries with connectors of different shapes and cross-sections were selected, and the measured current-carrying results, simulation results, and calculated results of the battery connectors were compared.

7. A lithium battery connector current carrying capacity calculation and verification system, characterized in that: include: A model building module, used to build a mathematical model for calculating the current carrying capacity of a uniform cross-section connector and a mathematical model for calculating the current carrying capacity of a variable cross-section connector; An equivalent model construction module is used to introduce efficiency to construct an equivalent calculation model for the current carrying capacity of battery connectors with different cross-sectional shapes based on the mathematical model for calculating the current carrying capacity of the uniform cross-sectional connector and the mathematical model for calculating the current carrying capacity of the variable cross-sectional connector; A test setting module is used to set the temperature sensing test rules of the single battery and obtain the numerical range of the temperature parameter in the current carrying equivalent calculation model of the battery connecting pieces with different cross-sectional shapes through the temperature sensing test; The verification module is used to select a temperature parameter within the value range of the temperature parameter and substitute it into the current-carrying equivalent calculation model of battery connectors with different cross-sectional shapes to perform calculation and verify the accuracy of the model.

8. A lithium battery connector current carrying capacity calculation and verification system according to claim 7, characterized in that: The test setting module sets the single cell temperature sensing test rules including: Set up temperature sensing test methods, test samples and test equipment; The temperature sensing test method includes a unified charging and discharging method, a battery built-in temperature sensing wire wiring method and the same measurement point; The test samples include lithium batteries of different capacities; The test equipment includes a data recording instrument, a power supply, a test cabinet and a temperature sensing line.

9. An electronic device, characterized in that: The processor, the communication interface, the memory and the communication bus are connected to each other via the communication bus. Memory for storing computer programs; A processor is used to execute a program stored in a memory to implement the method for calculating and verifying the current carrying capacity of a lithium battery connector according to any one of claims 1 to 6.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for calculating and verifying the current-carrying capacity of a lithium battery connector according to any one of claims 1 to 6 is implemented.

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