Battery design parameter determination method and device, electronic equipment and storage medium

Abstract

The invention discloses a battery design parameter determination method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining a charging platform voltage and a discharging platform voltage of each cycle period in a battery charging and discharging test process; determining a shift voltage and a resistance voltage of each cycle period according to the charging platform voltage and the discharging platform voltage, and drawing a first discrete curve of the shift voltage and a second discrete curve of the resistance voltage by taking the number of charge and discharge cycles as an independent variable; determining a first intersection point between a first exponential decreasing section and a first linear transition section of the first discrete curve, so as to determine the formation time of the stable SEI film according to the charge-discharge cycle index of the first intersection point; and determining a second intersection point between a second exponential decreasing section and a second linear transition section of the second discrete curve, so as to determine the complete infiltration time of the battery according to the charge-discharge cycle index of the second intersection point. According to the method, the formation time of the stable SEI film and the complete infiltration time of the battery can be determined.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method, apparatus, electronic device, and storage medium for determining battery design parameters. Background Technology

[0002] In lithium-ion battery manufacturing, formation refers to the crucial process step of building a stable solid electrolyte interphase (SEI) film on the negative electrode surface during the first charge and discharge cycle. SEI film formation occurs during the first charge stage of the battery, and a stable SEI film is a fundamental prerequisite for lithium-ion batteries to achieve normal charge and discharge functions and maintain good electrochemical performance. Battery wetting, as a necessary pretreatment step before formation, has a decisive impact on the quality of subsequent SEI film formation. The battery complete wetting time refers to the time required for the electrolyte to fully penetrate into the pore structure of the electrodes and separator. This process ensures effective contact between the active materials and the electrolyte, providing conditions for the formation of a uniform and stable SEI film. In lithium battery design and process development, the formation time of a stable SEI film and the battery complete wetting time are two core process parameters. Determining these parameters helps improve battery design efficiency and electrochemical performance. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a method, apparatus, electronic device, and storage medium for determining battery design parameters, capable of determining the formation time of a stable SEI film and the battery's complete immersion time.

[0004] In a first aspect, embodiments of the present invention provide a method for determining battery design parameters, including: During the battery charge and discharge test, the charging plateau voltage and discharging plateau voltage of each cycle are obtained; Based on the charging platform voltage and the discharging platform voltage, the shift voltage and resistance voltage for each cycle are determined, and the first discrete curve of the shift voltage and the second discrete curve of the resistance voltage are plotted with the number of charge and discharge cycles as the independent variable. The first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve is determined, so as to determine the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection point; A second intersection point is determined between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, so as to determine the battery full immersion time based on the number of charge-discharge cycles at the second intersection point.

[0005] According to some embodiments of the present invention, determining the shift voltage and resistance voltage for each cycle based on the charging platform voltage and the discharging platform voltage includes: The displacement voltage for each cycle is determined based on the average of the sum of the charging platform voltage and the discharging platform voltage.

[0006] According to some embodiments of the present invention, determining the shift voltage and resistance voltage for each cycle based on the charging platform voltage and the discharging platform voltage includes: The resistor voltage for each cycle is determined based on the average difference between the charging platform voltage and the discharging platform voltage.

[0007] According to some embodiments of the present invention, determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve includes: Observe and fit the first exponentially decreasing segment and the first linear transition segment of the first discrete curve based on the increasing and decreasing properties of the first discrete curve. Determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment.

[0008] According to some embodiments of the present invention, determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve includes: Observe and fit the second exponentially decreasing segment and the second linear transition segment of the second discrete curve based on the increasing and decreasing properties of the second discrete curve; Determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment.

[0009] According to some embodiments of the present invention, determining the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection includes: The formation time of the stable SEI film is determined based on the number of charge-discharge cycles at the first intersection and the duration of each cycle.

[0010] According to some embodiments of the present invention, determining the battery complete immersion time based on the number of charge-discharge cycles at the second intersection includes: The battery immersion time is determined based on the number of charge-discharge cycles at the second intersection and the duration of each cycle.

[0011] Secondly, embodiments of the present invention provide a battery design parameter determination device, comprising: The data acquisition module is used to acquire the charging plateau voltage and discharging plateau voltage of each cycle during the battery charge and discharge test. The curve plotting module is used to determine the shift voltage and resistance voltage of each cycle based on the charging platform voltage and the discharging platform voltage, and plot the first discrete curve of the shift voltage and the second discrete curve of the resistance voltage with the number of charging and discharging cycles as the independent variable. The first determining module is used to determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, so as to determine the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection point. The second determining module is used to observe and determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, so as to determine the battery full immersion time based on the number of charge-discharge cycles at the second intersection point.

[0012] Thirdly, embodiments of the present invention provide an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor, when running the computer program, implements the above-described method for determining battery design parameters.

[0013] Fourthly, embodiments of the present invention provide a storage medium storing a computer program that, when run, implements the above-described method for determining battery design parameters.

[0014] The embodiments of the present invention have at least the following beneficial effects: In this embodiment of the invention, a first discrete curve of the shift voltage and a second discrete curve of the resistance voltage are plotted. By determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, the formation time of the stable SEI film can be determined based on the number of charge-discharge cycles at the first intersection point. By determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, the battery full immersion time can be determined based on the number of charge-discharge cycles at the second intersection point. This is beneficial for improving battery design efficiency and electrochemical performance.

[0015] Additional aspects and advantages 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

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart illustrating the steps of the battery design parameter determination method according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the first discrete curve in an embodiment of the present invention; Figure 3 This is a schematic diagram of the second discrete curve in an embodiment of the present invention; Figure 4 This is a schematic block diagram of the battery design parameter determination device according to an embodiment of the present invention; Figure 5 This is a schematic block diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, and "above," "below," "within," etc. are understood to include the stated number. If "first," "second," etc. are used in the description, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0019] Please refer to Figure 1 This embodiment discloses a method for determining battery design parameters, including steps S100 to S400. It should be noted that the numbering of the steps in this embodiment is only for ease of review and understanding, and not to limit the execution order of the steps. The details of each step are described below: S100. During the battery charge and discharge test, obtain the charging plateau voltage and discharging plateau voltage for each cycle. S200. Based on the charging platform voltage and the discharging platform voltage, determine the shift voltage and resistance voltage for each cycle, and plot the first discrete curve of the shift voltage and the second discrete curve of the resistance voltage with the number of charging and discharging cycles as the independent variable. S300, Determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, so as to determine the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection point; S400, determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, and determine the battery full immersion time based on the number of charge-discharge cycles at the second intersection point.

[0020] For example, in the research and development and performance optimization of lithium-ion batteries, monitoring and analyzing key parameters during battery cycling is crucial. Among these, the charging plateau voltage (denoted as Vav,c) and discharging plateau voltage (denoted as Vav,d) are core indicators for evaluating the battery's electrochemical behavior. Specifically, in the nth charge-discharge cycle, the charging plateau voltage is denoted as Vav,cn, and the discharging plateau voltage is denoted as Vav,dn. Based on these voltage data, two key derived parameters can be further derived: shift voltage (SV) and resistance voltage (RV). The shift voltage reflects the voltage change caused by the loss of active lithium, while the resistance voltage characterizes the average voltage change caused by the increase in the battery's internal impedance. Existing technologies often predict battery cycle failure (i.e., "cycle failure") by plotting shift voltage curves (SVC) and resistance voltage curves (RVC). However, this embodiment proposes a more refined analysis method: using the number of charge-discharge cycles as the independent variable, a first discrete curve of the shift voltage composed of discrete points is plotted (e.g., ...). Figure 2 (as shown) and a second discrete curve regarding the resistor voltage (as shown) Figure 3 (As shown). The first and second discrete curves are not fitted curves, but are discrete point sets directly based on experimental data, thus more realistically reflecting the dynamic evolution process of the battery.

[0021] From an electrochemical mechanism perspective, the change in shift voltage is closely related to the formation process of the solid electrolyte interphase (SEI) film. The SEI film is a passivation film formed on the negative electrode surface during the first charge-discharge cycle of a lithium-ion battery. It has a dense structure and ion conductivity, effectively preventing the continuous decomposition of the electrolyte, but it also irreversibly consumes active lithium. The formation of the SEI film is a multi-stage process: in the initial charging stage, a complete protective layer has not yet formed on the electrode surface, and the electrolyte is in direct contact with the negative electrode material, leading to rapid loss of active lithium and reduction decomposition of solvent molecules. At this time, the shift voltage drops significantly. As cycling progresses, the SEI film gradually grows and stabilizes, forming a dense inorganic-organic composite layer (such as one containing Li₂CO₃, Li₂O, etc.). The rate of active lithium loss slows down, and the change in shift voltage becomes more gradual. This dynamic process is reflected in the first discrete curve, manifested as a rapidly decreasing first exponentially decreasing segment (e.g., ...). Figure 2 (as shown by label L1) and the first linear transition segment with a gentle descent rate (as shown by label L1) Figure 2 (As shown in label L2). The first intersection point between these two segments can be identified using mathematical fitting methods (such as a combination of exponential decay and linear function fitting). Figure 2 As shown in the label P1), the number of cycles corresponding to the first intersection point is the formation time of the stable SEI film, marking the transition of the SEI film from the growth stage to the stable stage.

[0022] On the other hand, the change in resistance voltage is mainly related to the battery wetting process. Battery wetting refers to the diffusion and distribution of the electrolyte in the electrode pores and separator, and its sufficiency directly affects the conductivity of the ion transport path and the internal impedance. In the initial state of the battery, the electrolyte has not fully filled the porous structure of the electrode, resulting in greater ion transport resistance and a higher resistance voltage. As the charge-discharge cycle progresses, the electrolyte gradually wets the electrode material, optimizing the ion migration path, improving interfacial contact, reducing the battery's internal impedance, and causing the resistance voltage to show a decreasing trend. When the electrolyte completely wets the electrode, the impedance change tends to saturate, and the rate of decrease in resistance voltage slows down significantly. This process is represented in the second discrete curve as a second exponentially decreasing segment with a relatively fast decrease rate (e.g., ...). Figure 3 (as shown by marker L3) and a second linear transition phase with a gentler descent rate (as shown by...). Figure 3 (As shown in marker L4). A similar curve fitting method can be used to determine the second intersection point between the two segments (e.g., ...). Figure 3 As shown in the mark P2), the number of cycles corresponding to the second intersection point is the battery's complete immersion time, indicating that the electrolyte has fully penetrated into the electrode's internal microstructure.

[0023] It is important to note that the first and second intersection points are fuzzy boundary points based on curve fitting, rather than precise points calculated mathematically. After obtaining the stable SEI film formation time and the battery's full immersion time, these parameters can provide crucial guidance for battery optimization design. For example, if the SEI film formation time is too long, the formation process may need to be adjusted (such as optimizing the charging cutoff voltage or temperature) to promote the rapid formation of a dense SEI; if the immersion time is too long, the electrode pore structure or electrolyte formulation needs to be improved to enhance wettability. Through an iterative cycle of "design-charge-discharge testing-parameter determination-optimization design," battery performance (such as cycle life and rate characteristics) can be gradually optimized until the ideal state is achieved. This method is not only applicable to conventional lithium-ion batteries but can also be extended to novel battery systems (such as solid-state batteries), providing a general optimization framework for battery development based on dynamic parameter monitoring.

[0024] Step S200: Determine the shift voltage and resistor voltage for each cycle based on the charging platform voltage and discharging platform voltage, including: The displacement voltage for each cycle is determined by the average of the sum of the charging platform voltage and the discharging platform voltage.

[0025] For example, the shift in average operating voltage during battery cycling is primarily due to the irreversible consumption of active lithium. In each cycle, some lithium ions participate in the formation and repair of the SEI film or are captured by side reactions, leading to a continuous decrease in the total amount of freely mobile active lithium within the battery system. This loss of lithium reserves directly manifests as a change in battery polarization characteristics, causing a systematic shift in its average operating voltage. Determining the shift voltage based on the average of the sum of the charging and discharging plateau voltages can effectively capture this voltage change trend, dominated by active lithium loss and increasing with the number of cycles, thereby effectively separating and identifying voltage decay caused by material loss from voltage changes caused by increased impedance.

[0026] Step S200: Determine the shift voltage and resistor voltage for each cycle based on the charging platform voltage and discharging platform voltage, including: The resistor voltage for each cycle is determined based on the average difference between the charging platform voltage and the discharging platform voltage.

[0027] For example, the difference between the charging and discharging plateau voltages (i.e., the hysteresis) primarily stems from the total impedance encountered by lithium ions as they migrate through the electrode materials, electrolyte, SEI film, and at different interfaces. This impedance is composed of ohmic impedance, electrochemical polarization impedance, and concentration polarization impedance. A larger voltage difference indicates greater resistance to ion migration and more severe internal polarization of the battery. By calculating the mean of this difference, the overall internal resistance state of the battery at a specific cycle can be characterized, and the combined effect of active lithium loss on the average voltage can be removed, thus measuring the voltage change component caused by impedance factors.

[0028] In step S300, determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve includes: Observe and fit the first exponentially decreasing segment and the first linear transition segment of the first discrete curve based on the increasing and decreasing properties of the first discrete curve. Determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment.

[0029] For example, please refer to Figure 2The nonlinear characteristic of the shift voltage, exhibiting a "rapid decrease followed by a slow transition" on the first discrete curve, is a direct reflection of the SEI film formation mechanism. The first exponentially decreasing segment corresponds to the rapid growth period of the SEI film. During this stage, the fresh electrode surface reacts violently with the electrolyte, and a large amount of lithium is rapidly consumed to construct the initial, potentially porous SEI layer, leading to a sharp decrease in the active lithium reserve, reflected in the rapid exponential decay of the shift voltage. The first linear transition segment corresponds to the stabilization and repair period of the SEI film. At this time, a dense and stable SEI film has been basically formed, effectively blocking direct contact between the electrolyte and the electrode. The side reaction rate is significantly reduced, and the loss rate of active lithium tends to be constant and slow, reflected in the linear and slow change of the shift voltage. The first intersection point is determined by curve fitting. The first intersection point reflects the shift of the SEI film from "formation-dominant" to "repair-dominant". By determining the first intersection point, a clear and quantitative target can be provided for the optimization of the battery formation process. For example, the goal is to adjust the formation regime (such as current, voltage, and temperature) to advance and shorten the exponential decline stage as much as possible, thereby reducing unnecessary initial lithium consumption and improving the battery's first coulombic efficiency and cycle life.

[0030] In step S400, determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve includes: Observe and fit the second exponentially decreasing segment and the second linear transition segment of the second discrete curve based on the increasing and decreasing properties of the second discrete curve; Determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment.

[0031] For example, please refer to Figure 3 The trend of "rapid decrease followed by gradual stabilization" in the resistance and voltage reflects the gradual penetration and equilibrium of the electrolyte in the porous electrode structure of the battery. The second exponentially decreasing segment corresponds to the rapid wetting period of the electrolyte. In the initial stage of cycling, the electrolyte rapidly fills the large-pore pores in the electrodes and separator under capillary action, quickly opening up ion transport pathways and causing a rapid decrease in the overall internal resistance of the battery. The second linear transition segment corresponds to the slow equilibrium and saturation period of the electrolyte. After most of the easily filled pores are filled, the electrolyte requires a longer time to gradually penetrate into the fine and tortuous nanoscale pores until a state of complete wetting equilibrium is reached, and the rate of decrease in internal resistance slows down significantly and tends to stabilize. The second intersection point is determined by curve fitting. The second intersection point marks the critical point where the electrolyte transitions from "rapid filling" to "slow saturation," which is the theoretical time for complete wetting. This allows for precise control of the electrolyte injection volume, setting of immersion time and conditions (such as high-temperature settling), ensuring that the battery cells reach the optimal immersion state before leaving the factory, thereby avoiding uneven battery performance, shortened cycle life, and even safety hazards caused by insufficient immersion.

[0032] In step S300, the formation time of the stable SEI film is determined based on the number of charge-discharge cycles at the first intersection, including: The formation time of the stable SEI film is determined based on the number of charge-discharge cycles at the first intersection and the duration of each cycle.

[0033] For example, the number of cycles alone only represents the number of electrochemical reactions. However, by combining the number of cycles with the actual duration of each cycle (controlled by charge and discharge regimes such as current and cutoff voltage), the formation time of a stable SEI film can be reasonably measured, providing quantitative data for the optimization of battery design parameters.

[0034] In step S400, the battery complete immersion time is determined based on the number of charge-discharge cycles at the second intersection, including: The battery immersion time is determined based on the number of charge-discharge cycles at the second intersection and the duration of each cycle.

[0035] For example, similar to the above scheme, the cycle node of the immersion completion is converted into the actual complete immersion time, which reflects the permeation efficiency of the electrolyte under specific cell designs (such as electrode thickness, porosity, and separator type) and specific operating conditions (such as current and temperature), and can provide quantitative data for the optimization of battery design parameters.

[0036] Please refer to Figure 4 Based on the same technical concept as the above embodiments, this embodiment also provides a battery design parameter determination device, including: The data acquisition module 110 is used to acquire the charging platform voltage and discharging platform voltage of each cycle during the battery charging and discharging test. The curve plotting module 120 is used to determine the shift voltage and resistance voltage of each cycle based on the charging platform voltage and the discharging platform voltage, and plot the first discrete curve of the shift voltage and the second discrete curve of the resistance voltage with the number of charging and discharging cycles as the independent variable. The first determining module 130 is used to determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, so as to determine the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection point. The second determining module 140 is used to observe and determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, so as to determine the battery full immersion time based on the number of charge-discharge cycles at the second intersection point.

[0037] This embodiment plots a first discrete curve of the shift voltage and a second discrete curve of the resistance voltage. By determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, the formation time of the stable SEI film can be determined based on the number of charge-discharge cycles at the first intersection point. Similarly, by determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, the battery's complete immersion time can be determined based on the number of charge-discharge cycles at the second intersection point. This is beneficial for improving battery design efficiency and electrochemical performance. It should be noted that any aspects of the battery design parameter determination device not covered in this embodiment can be referred to in the aforementioned battery design parameter determination method embodiment, and will not be repeated here.

[0038] Please refer to Figure 5 This embodiment provides an electronic device, including a processor 210 and a memory 220. The memory 220 stores a computer program, and the processor 210 executes the computer program to implement the above-described method for determining battery design parameters. Details of the method for determining battery design parameters can be found above and will not be repeated here. This embodiment plots a first discrete curve of the shift voltage and a second discrete curve of the resistance voltage. By determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, the formation time of the stable SEI film can be determined based on the number of charge-discharge cycles at the first intersection point. By determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, the battery complete immersion time can be determined based on the number of charge-discharge cycles at the second intersection point, which is beneficial for improving battery design efficiency and electrochemical performance.

[0039] This embodiment provides a storage medium storing a computer program. When the computer program is run, it implements the battery design parameter determination method described above. Details of the battery design parameter determination method can be found above and will not be repeated here. This embodiment plots a first discrete curve of the shift voltage and a second discrete curve of the resistance voltage. By determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, the formation time of the stable SEI film can be determined based on the number of charge-discharge cycles at the first intersection point. By determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, the battery complete immersion time can be determined based on the number of charge-discharge cycles at the second intersection point. This is beneficial for improving battery design efficiency and electrochemical performance.

[0040] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for determining battery design parameters, characterized in that, include: During the battery charge and discharge test, the charging plateau voltage and discharging plateau voltage of each cycle are obtained; Based on the charging platform voltage and the discharging platform voltage, the shift voltage and resistance voltage for each cycle are determined, and the first discrete curve of the shift voltage and the second discrete curve of the resistance voltage are plotted with the number of charge and discharge cycles as the independent variable. The first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve is determined, so as to determine the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection point; A second intersection point is determined between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, so as to determine the battery full immersion time based on the number of charge-discharge cycles at the second intersection point.

2. The method for determining battery design parameters according to claim 1, characterized in that, The step of determining the shift voltage and resistance voltage for each cycle based on the charging platform voltage and the discharging platform voltage includes: The displacement voltage for each cycle is determined based on the average of the sum of the charging platform voltage and the discharging platform voltage.

3. The method for determining battery design parameters according to claim 1 or 2, characterized in that, The step of determining the shift voltage and resistance voltage for each cycle based on the charging platform voltage and the discharging platform voltage includes: The resistor voltage for each cycle is determined based on the average difference between the charging platform voltage and the discharging platform voltage.

4. The method for determining battery design parameters according to claim 1, characterized in that, Determining the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve includes: Observe and fit the first exponentially decreasing segment and the first linear transition segment of the first discrete curve based on the increasing and decreasing properties of the first discrete curve. Determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment.

5. The method for determining battery design parameters according to claim 1, characterized in that, Determining the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve includes: Observe and fit the second exponentially decreasing segment and the second linear transition segment of the second discrete curve based on the increasing and decreasing properties of the second discrete curve; Determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment.

6. The method for determining battery design parameters according to claim 1 or 4, characterized in that, The step of determining the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection includes: The formation time of the stable SEI film is determined based on the number of charge-discharge cycles at the first intersection and the duration of each cycle.

7. The method for determining battery design parameters according to claim 1 or 5, characterized in that, The step of determining the battery's complete immersion time based on the number of charge-discharge cycles at the second intersection includes: The battery immersion time is determined based on the number of charge-discharge cycles at the second intersection and the duration of each cycle.

8. A battery design parameter determination device, characterized in that, include: The data acquisition module is used to acquire the charging plateau voltage and discharging plateau voltage of each cycle during the battery charge and discharge test. The curve plotting module is used to determine the shift voltage and resistance voltage of each cycle based on the charging platform voltage and the discharging platform voltage, and plot the first discrete curve of the shift voltage and the second discrete curve of the resistance voltage with the number of charging and discharging cycles as the independent variable. The first determining module is used to determine the first intersection point between the first exponentially decreasing segment and the first linear transition segment of the first discrete curve, so as to determine the formation time of the stable SEI film based on the number of charge-discharge cycles at the first intersection point. The second determining module is used to observe and determine the second intersection point between the second exponentially decreasing segment and the second linear transition segment of the second discrete curve, so as to determine the battery full immersion time based on the number of charge-discharge cycles at the second intersection point.

9. An electronic device comprising a processor and a memory, wherein the memory stores a computer program, characterized in that, When the processor runs the computer program, it is used to implement the battery design parameter determination method as described in any one of claims 1 to 7.

10. A storage medium storing a computer program, characterized in that, When the computer program is run, it implements the battery design parameter determination method as described in any one of claims 1 to 7.

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