Method, device, computer equipment and storage medium for estimating in-plane distribution of battery contact resistance

Abstract

The present application relates to a method, device, computer equipment and storage medium for estimating the in-plane distribution of battery contact resistance. The method comprises: operating the battery to be tested under stable operating conditions, collecting the current density distribution of each region in the battery to be tested; each region is obtained by dividing according to the cathode flow field structure and the anode flow field structure of the battery to be tested; when the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each region, and the ohmic impedance of each region is determined, and the preset state conditions are set to match the stable operating conditions; based on the ohmic impedance of each region, the contact resistance of each region is determined. The membrane is fully hydrated by the stable operation of the battery at high humidity and high current, so that the membrane impedance of different regions in the surface is approximately equal. The accuracy of identifying the contact resistance of the battery to be tested is improved.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a method, apparatus, computer equipment, and storage medium for estimating the in-plane distribution of battery contact resistance. Background Art

[0002] During the assembly of large-area fuel cells, cylinder compression and bolt tightening methods can result in uneven distribution of preload force. During operation, the preload force can also be unevenly distributed due to factors such as heat generation, thermal expansion and contraction, and expansion and contraction of the membrane electrode during charging and draining. This uneven distribution of preload force can cause variations in the contact resistance distribution across different parts of the fuel cell, thus affecting fuel cell performance. Therefore, it is necessary to estimate the in-plane distribution of contact resistance within the fuel cell.

[0003] In traditional technology, pressure-sensitive test paper is placed at a specific position during the stacking process, and then a pre-tightening force is applied to the battery stack. The stack is then disassembled and the pressure-sensitive paper is removed. The color difference of the pressure-sensitive test paper is analyzed to obtain the pressure distribution within the surface, and then the contact resistance distribution within the surface is determined based on the pressure distribution within the surface.

[0004] However, the traditional method for estimating the in-plane distribution of battery contact resistance suffers from inaccurate estimation. Summary of the Invention

[0005] Based on this, it is necessary to provide a method, device, computer equipment and storage medium for estimating the in-plane distribution of battery contact resistance that can improve the estimation accuracy in order to address the above technical problems.

[0006] In a first aspect, the present application provides a method for estimating the in-plane distribution of battery contact resistance, the method comprising:

[0007] Operating the battery under test under stable operating conditions, collecting current density distribution of each region in the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0008] When the state of the battery to be tested meets a preset state condition, ohmic impedance distribution identification is performed according to the current density of each of the regions to determine the ohmic impedance of each of the regions; the preset state condition is set to match the stable operation condition;

[0009] The contact resistance of each of the regions is determined based on the ohmic impedance of each of the regions.

[0010] In one embodiment, determining the contact resistance of each of the regions based on the ohmic impedance of each of the regions includes:

[0011] Determining the electron transfer impedance and membrane impedance of each of the regions according to the physical characteristics of the battery to be tested;

[0012] The contact resistance of each of the regions is determined based on the electron transfer impedance, the film impedance, and the ohmic impedance.

[0013] In one embodiment, the identifying the ohmic impedance distribution according to the current density of each of the regions to determine the ohmic impedance of each of the regions includes:

[0014] Determining a proportionality coefficient between the ohmic impedance of each region and the total ohmic impedance of the battery to be tested based on the current density of each region, the area of ​​each region, and a preset relationship formula; wherein the preset relationship formula is a correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region;

[0015] The ohmic impedance of each of the regions is determined according to the proportional coefficient and the preset relationship.

[0016] In one embodiment, determining the proportionality coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery to be tested based on the current density of each region, the area of ​​each region, and a preset correlation relationship includes:

[0017] Determining a first relationship according to the current density of each of the regions and the area of ​​each of the regions;

[0018] The proportional coefficient is determined according to the first relational expression and the preset relational expression.

[0019] In one embodiment, the method further comprises:

[0020] According to the current density distribution, determine whether the state of the battery to be tested meets the preset state conditions; the preset state conditions include equipotential within the surface, each of the regions does not reach the concentration polarization control region, and the current proportion of each of the regions within the first-level preset current density range is the same.

[0021] In one embodiment, determining whether the state of the battery to be tested meets a preset state condition according to the current density distribution includes:

[0022] determining whether the state of the battery under test satisfies in-plane equipotential according to the overlap of the first polarization curves, wherein the first polarization curve is determined according to the current density distribution of the battery under test;

[0023] When the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions reaches the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each of the regions;

[0024] When the state of the battery to be tested satisfies that none of the regions reaches the concentration polarization control region, whether the state of the battery to be tested meets a preset state condition is determined according to a ratio of the current of each region to the current of the battery to be tested.

[0025] In a second aspect, the present application further provides a device for estimating the in-plane distribution of battery contact resistance, comprising:

[0026] an acquisition module, configured to operate the battery under test under stable operating conditions and acquire current density distribution in each region of the battery under test; each region being divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0027] an identification module, configured to identify the ohmic impedance distribution according to the current density of each of the regions and determine the ohmic impedance of each of the regions when the state of the battery to be tested meets a preset state condition, wherein the preset state condition is set to match the stable operation condition;

[0028] The first determining module is configured to determine the contact resistance of each of the regions according to the ohmic impedance of each of the regions.

[0029] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0030] Operating the battery under test under stable operating conditions, collecting current density distribution of each region in the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0031] When the state of the battery to be tested meets a preset state condition, ohmic impedance distribution identification is performed according to the current density of each of the regions to determine the ohmic impedance of each of the regions; the preset state condition is set to match the stable operation condition;

[0032] The contact resistance of each of the regions is determined based on the ohmic impedance of each of the regions.

[0033] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0034] Operating the battery under test under stable operating conditions, collecting current density distribution of each region in the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0035] When the state of the battery to be tested meets a preset state condition, ohmic impedance distribution identification is performed according to the current density of each of the regions to determine the ohmic impedance of each of the regions; the preset state condition is set to match the stable operation condition;

[0036] The contact resistance of each of the regions is determined based on the ohmic impedance of each of the regions.

[0037] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the following steps:

[0038] Operating the battery under test under stable operating conditions, collecting current density distribution of each region in the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0039] When the state of the battery to be tested meets a preset state condition, ohmic impedance distribution identification is performed according to the current density of each of the regions to determine the ohmic impedance of each of the regions; the preset state condition is set to match the stable operation condition;

[0040] The contact resistance of each of the regions is determined based on the ohmic impedance of each of the regions.

[0041] The above-mentioned method, device, computer equipment and storage medium for estimating the in-plane distribution of battery contact resistance operate the battery to be tested under stable operating conditions and collect the current density distribution of each region in the battery to be tested; each region is obtained by dividing according to the cathode flow field structure and the anode flow field structure of the battery to be tested; when the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each region to determine the ohmic impedance of each region, and the preset state conditions are set to match the stable operating conditions; based on the ohmic impedance of each region, the contact resistance of each region is determined. The membrane is fully hydrated by stably operating the battery at high humidity and high current, so that the membrane impedance of different regions in the surface is approximately equal. The battery to be tested is operated under stable operating conditions so that the state of the battery to be tested can meet the preset state conditions, and the ohmic impedance distribution is identified using the current density of each region under this state, which improves the accuracy of the determined ohmic impedance of each region, thereby improving the accuracy of identifying the contact resistance of the battery to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A diagram illustrating an application environment of a method for estimating the in-plane distribution of battery contact resistance according to an embodiment;

[0044] Figure 2 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in one embodiment;

[0045] Figure 3 is a schematic diagram of a cathode flow field structure in one embodiment;

[0046] Figure 4 is a schematic diagram of an anode flow field structure in one embodiment;

[0047] Figure 5 Schematic diagram of the in-plane area division of a battery to be tested in one embodiment;

[0048] Figure 6 Schematic diagram of the inlet voltage and outlet voltage polarization curves of a battery under test in one embodiment;

[0049] Figure 7 Schematic diagram of partitioned polarization curves of a battery to be tested in one embodiment;

[0050] Figure 8 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in another embodiment;

[0051] Figure 9 Schematic diagram of contact pressure distribution on the upper side of a battery in one embodiment;

[0052] Figure 10 Schematic diagram of contact pressure distribution on the lower side of a battery in one embodiment;

[0053] Figure 11 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in another embodiment;

[0054] Figure 12 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in another embodiment;

[0055] Figure 13 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in another embodiment;

[0056] Figure 14 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in another embodiment;

[0057] Figure 15 Schematic diagram of the current proportions of different partitions at each steady-state point of the polarization curve in one embodiment;

[0058] Figure 16 1 is a flow chart of a method for estimating the in-plane distribution of battery contact resistance in another embodiment;

[0059] Figure 17 1 is a structural block diagram of a device for estimating the in-plane distribution of battery contact resistance according to one embodiment;

[0060] Figure 18 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0062] During the assembly of large-area fuel cells, cylinder compression or bolt tightening methods can result in uneven distribution of preload force. During operation, heat generation, which causes thermal expansion and contraction, and expansion and contraction of the membrane electrode during charging and draining, can also lead to uneven distribution of preload force. This uneven distribution of preload force can cause variations in the contact resistance distribution of different parts of the fuel cell, thus affecting its performance.

[0063] Identifying the distribution of contact resistance within the fuel cell surface helps determine the distribution of battery contact pressure, analyze local hot spots that may arise internally, and analyze local mass transfer characteristics. It also helps decompose fuel cell polarization losses and better determine the causes of changes in fuel cell performance. It can also provide input for modeling large-area batteries and improve the accuracy of the model's predictions of internal states and performance.

[0064] In traditional technology, the method for obtaining the in-plane distribution of contact resistance of large-area fuel cells usually includes the following steps: (1) placing pressure-sensitive test paper at specific locations during the stacking process, including between the membrane electrode and the bipolar plate, between the bipolar plate and the end plate of the stack, etc.; (2) applying a preload to the fuel cell, such as by pressurizing the cylinder and applying torque to the bolts, and then leaving the fuel cell stationary to ensure that the pressure-sensitive paper fully responds to the preload; (3) disassembling the fuel cell and removing the pressure-sensitive paper, using professional equipment to perform color difference analysis on the pressure-sensitive test paper, etc., to obtain the in-plane pressure distribution; (4) calculating the in-plane contact resistance distribution based on the contact resistance and pressure relationship obtained during the preliminary experiment.

[0065] However, using the traditional method for estimating the in-plane distribution of battery contact resistance, when the membrane electrode material or bipolar plate is replaced, preliminary experiments and contact resistance distribution calculations need to be carried out again; secondly, obtaining the contact pressure distribution from pressure-sensitive paper requires the use of professional equipment to scan the pressure-sensitive paper and perform data processing, which is costly and time-consuming; thirdly, it is difficult to ensure that the preload force distribution in different areas of the surface is completely consistent during the stacking process of different batches; finally, it may be necessary to adjust the stacking pressure to optimize performance, or during the long-term operation of the stack, the in-plane contact resistance distribution will change due to thermal expansion and contraction caused by heat generation and heat dissipation of the battery, and expansion and contraction caused by charging and discharging of the membrane electrode. At this time, re-measurement is required, which is inefficient.

[0066] Based on the above problems, the present application provides a method for estimating the in-plane distribution of battery contact resistance, which can improve the estimation accuracy.

[0067] The method for estimating the in-plane distribution of battery contact resistance provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the acquisition device 102 connected to the battery to be tested communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. The battery to be tested is operated under stable operating conditions, and the server 104 collects the current density distribution of each area in the battery to be tested through the acquisition device 102, thereby performing ohmic impedance distribution identification based on the current density of each area and determining the contact resistance of each area. Among them, the server 104 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides cloud computing services.

[0068] In one embodiment, Figure 2 As shown in the figure, a method for estimating the in-plane distribution of battery contact resistance is provided. Figure 1 The following is an example of a server in the example, including:

[0069] S201 , operating the battery under test under stable operating conditions, and collecting current density distribution in each region of the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test.

[0070] Among them, the stable operating condition can be operating under the operating conditions of high humidity, high oxygen concentration, and preset current density for more than a preset time. The high oxygen concentration is a high stoichiometric ratio. For example, when the humidity of the operating environment of the battery to be tested is greater than the humidity threshold, it can be regarded as reaching the high humidity operating condition; when the oxygen concentration of the operating environment is greater than the concentration threshold, it can be regarded as reaching the high oxygen concentration operating condition.

[0071] In the embodiment of the present application, the battery to be tested can be placed in an environmental simulation component, and the server can control the environmental simulation component according to a preset strategy to provide the battery to be tested with high humidity and high metering ratio operating conditions, and the battery to be tested can be operated at a preset current density for a preset time, and the high-frequency impedance and voltage of the battery to be tested are stable. Optionally, the preset current density can be 2A / cm 2 , the preset duration can be 30 minutes.

[0072] For example, the operating conditions in the embodiment of the present application can be an operating temperature of 65°C, pure hydrogen is introduced into the anode, and the stoichiometric ratio is 1.5; an oxygen-nitrogen balance gas with an oxygen concentration of 60% is introduced into the cathode, and the stoichiometric ratio is 1.8; the relative humidity of the anode and cathode intakes are both 80%, and the absolute intake pressure is both 150 kPa; a downstream mode is adopted, and the anode and cathode intake on the same side.

[0073] Optionally, the in-plane area of ​​the battery to be tested is divided in advance according to the cathode flow field structure and the anode flow field structure of the battery to be tested. The battery to be tested can be divided into three parts: the gas inlet transition area, the mainstream field area, and the gas outlet area. Combined with the relative positions of the cathode plate and the anode plate during assembly, the in-plane area of ​​the battery is divided into seven areas. For example, the cathode flow field structure of the battery to be tested can be as follows: Figure 3 As shown, the anode flow field structure of the battery to be tested can be as follows Figure 4 As shown, further, Figure 5 As shown, the seven regions in the in-plane area of ​​the battery include: ① inlet pure cathode transition zone; ② inlet pure anode transition zone; ③ inlet cathode and cathode transition intersection zone; ④ outlet pure cathode transition zone; ⑤ outlet pure anode transition zone; ⑥ outlet cathode and cathode transition intersection zone; ⑦ mainstream field region.

[0074] In an embodiment of the present application, under stable operating conditions, the current density of the battery to be tested is determined based on the current applied to the battery to be tested and the active area of ​​the battery to be tested. Based on the current density, the frequency of collecting the voltage of the battery to be tested is determined. Optionally, the collected voltage of the battery to be tested may include the outlet voltage, the import voltage, and the voltage of each region.

[0075] For example, at 0.2 A / cm 2 -2A / cm 2 Within the current density range, the current can be increased by 0.2A / cm 2 Take a point; at 0-0.2A / cm 2 Within the current density range, narrow the current density range of the sampling point to prepare for subsequent polarization decomposition.

[0076] Optionally, a test polarization curve can be generated based on the current density and the voltage corresponding to the current density. The inlet voltage and outlet voltage polarization curves of the battery to be tested are as follows: Figure 6 As shown, the partition polarization curve of the battery to be tested is as follows Figure 7 shown.

[0077] S202 , when the state of the battery to be tested meets a preset state condition, ohmic impedance distribution identification is performed according to the current density of each region to determine the ohmic impedance of each region, where the preset state condition is set to match the stable operation condition.

[0078] Among them, the preset state conditions can be that the voltage of the battery to be tested is stable, the temperature of the battery to be tested is stable, the output power of the battery to be tested is stable, etc., or the preset state conditions can include that the surface of the battery to be tested is approximately equipotential, the current range of the test polarization curve of each area of ​​the battery to be tested does not reach the concentration polarization control area, and the current proportion of each area of ​​the battery to be tested remains unchanged.

[0079] In an embodiment of the present application, under stable operating conditions, the state of the battery to be tested can meet the preset state conditions. Furthermore, the ohmic impedance of each region can be determined based on the current density of each region, the current density of the battery to be tested and a preset expression; or, the ohmic resistance of each region can be determined based on the current density of each region, the current density of the battery to be tested and a preset correspondence.

[0080] S203 , determining the contact resistance of each region according to the ohmic impedance of each region.

[0081] In the embodiment of the present application, the ohmic impedance is composed of the contact resistance and other resistances of the battery under test. The other resistances of the battery under test can be identified, and the contact resistance of each region can be determined based on the other resistances and ohmic impedance of each region. As an optional implementation, the other resistances of each region of the battery under test can be determined based on information such as the battery type and internal battery parameters of the battery under test. As another optional implementation, the other resistances of each region of the battery under test can be determined through simulation.

[0082] In the above-mentioned method for estimating the in-plane distribution of battery contact resistance, the battery to be tested is operated under stable operating conditions, and the current density distribution of each region in the battery to be tested is collected; each region is obtained by dividing according to the cathode flow field structure and the anode flow field structure of the battery to be tested; when the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each region to determine the ohmic impedance of each region, and the preset state conditions are set to match the stable operating conditions; based on the ohmic impedance of each region, the contact resistance of each region is determined. The membrane is fully hydrated by stably operating the battery at high humidity and high current, so that the membrane impedance of different regions in the surface is approximately equal. The battery to be tested is operated under stable operating conditions so that the state of the battery to be tested can meet the preset state conditions, and the ohmic impedance distribution is identified using the current density of each region under this state, which improves the accuracy of the determined ohmic impedance of each region, thereby improving the accuracy of identifying the contact resistance of the battery to be tested.

[0083] In one embodiment, an implementation of the above S203 is provided, such as Figure 8 As shown, the above “determining the contact resistance of each region based on the ohmic impedance of each region” includes:

[0084] S301 , determining the electron transfer impedance and membrane impedance of each region according to the physical characteristics of the battery to be tested.

[0085] In the embodiment of the present application, the electron transfer resistance is related to the flow channel morphology, carbon paper thickness, electron conductivity and other conditions of the battery to be tested. The electron transfer resistance can be determined based on the parameter information of the bipolar plate and carbon paper, and the electron transfer resistance is customized. In the embodiment of the present application, Figure 5 Regions ①-⑥ in the figure correspond to the gas transition zone of the flow channel. The flow channel inside this region is wide, and the electron transmission resistance below the flow channel is large. Region ⑦ is the mainstream field area, where the flow channel is narrow and the electron transmission resistance is small. The electronic resistance distribution obtained through modeling analysis can be shown in Table 1:

[0086] Table 1

[0087]

[0088] in, is the electron transfer resistance of the jth region.

[0089] In the embodiment of the present application, the battery is operated under stable operating conditions to fully hydrate the proton exchange membrane of the battery. It can be assumed that the membrane impedance inside each region of the battery is approximately the same, and the mode impedance of each region can be obtained by modeling analysis. For example, the proton exchange membrane used in the embodiment of the present application is 1A / cm2 at 65°C and under fully hydrated conditions. 2 The impedance at the current density is approximately Among them, the stable operating conditions are the operating conditions of high humidification and high current density.

[0090] S302 , determining the contact resistance of each region based on the electron transfer impedance, the membrane impedance, and the ohmic impedance.

[0091] In the embodiment of the present application, the ohmic impedance of the battery to be tested can be divided into membrane impedance, catalyst layer proton conduction impedance, electron transfer impedance, and contact resistance. The expression of the ohmic impedance of the battery to be tested can be ,in, is the ohmic impedance, is the membrane impedance, is the proton conduction impedance of the catalytic layer, is the electron transfer impedance, It should be noted that the membrane can be fully hydrated by operating the battery at high humidity and high current, making the membrane impedance in different areas of the surface approximately equal, and in a high humidity environment, the proton conduction resistance of the catalyst layer is Can be ignored.

[0092] In the embodiment of the present application, the electronic transfer impedance and the membrane impedance of each region are sequentially substituted into the expression of ohmic impedance to determine the contact resistance of each region. For example, based on the data in Table 1 above and the membrane impedance, , the contact resistance of each area can be determined as shown in Table 2:

[0093] Table 2

[0094]

[0095] in, is the contact resistance of the jth region.

[0096] For example, Figure 9 Schematic diagram of contact pressure distribution on the upper side of the battery. Figure 10 Schematic diagram of contact pressure distribution on the lower side of the battery. Figure 9 and Figure 10 The darker the color, the lower the pressure. Figure 5 、 Figure 9 and Figure 10 It can be seen that the contact pressure in the main flow field area (area ⑦) is significantly greater than that in the gas transition area of ​​the flow field (areas ①-⑥). The identification results in Table 4 also show that the contact resistance in area ⑦ is the smallest among all the areas in the surface. In addition, according to Figure 9 and Figure 10 It can also be found that the contact pressure on the upper side of the battery in area ① is relatively large, while the contact pressure in area ② is relatively small. Therefore, the size of the partitioned contact resistance identified by the method in the embodiment of the present application corresponds to the contact pressure test result.

[0097] In the above-mentioned application embodiment, the membrane is fully hydrated by stably operating the battery at high humidity and high current, so that the membrane impedance in different areas within the surface is approximately equal. Furthermore, the ohmic impedance decomposition is performed to obtain the contact resistance. Due to the stable operating conditions, the results of the ohmic impedance decomposition are more reliable, thereby improving the accuracy of the identified contact resistance.

[0098] In one embodiment, an implementation of the above S202 is provided, such as Figure 11 As shown, the above “identifying the ohmic impedance distribution according to the current density of each region and determining the ohmic impedance of each region” includes:

[0099] S401, determining a proportionality coefficient between the ohmic impedance of each region and the total ohmic impedance of the battery under test based on the current density of each region, the area of ​​each region, and a preset relationship; the preset relationship is a correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region.

[0100] In the embodiment of the present application, the current density of each region and the area of ​​each region can be substituted into the preset relationship to solve and determine the proportional coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery to be tested. The proportional coefficient can be expressed as , the proportionality coefficient is the ratio of the ohmic impedance of each zone to the ohmic impedance of the entire battery under test.

[0101] Optionally, the preset relationship may be as shown in Formula 1 and Formula 2:

[0102] (Formula 1)

[0103] (Equation 2)

[0104] in, is the Nernst voltage, Used to describe activation polarization; is the Tafel slope, which can be determined by testing the polarization curve; is the ohmic impedance.

[0105] S402: Determine the ohmic impedance of each region according to the proportional coefficient and a preset relationship.

[0106] In the embodiment of the present application, the overall ohmic impedance of the battery can be identified by the least square method based on the polarization curve of the battery as a whole and the preset relationship. For example, in the embodiment of the present application, the overall ohmic impedance of the battery can be identified. , further, using 1A / cm 2 The current distribution of each region is calculated by the test And then calculated As shown in Table 3:

[0107] Table 3

[0108]

[0109] In the above application embodiment, the ohmic impedance of each region is determined based on the proportional coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery to be tested. The determination method is safe and reliable, and the accuracy of the contact resistance is improved.

[0110] In one embodiment, an implementation of the above S401 is provided, such as Figure 12 As shown, the above “determining the proportional coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery to be tested based on the current density of each region, the area of ​​each region and the preset correlation relationship” includes:

[0111] S501 : Determine a first relationship according to the current density and the area of ​​each region.

[0112] In the embodiments of this application, Figure 5 The current densities in the ①-⑦ regions at the steady-state point k are The areas of each region are The average current density of the battery is The total battery area is , at the steady-state points 1 and 2 in the two medium current density regions, when the state of the battery under test meets the preset state conditions, the current proportion of each region remains unchanged, then the first relationship can be expressed as Equation 3:

[0113] (Equation 3)

[0114] Where j is the partition number, j = 1, 2..., 7. Further, we can make .

[0115] S502: Determine a proportional coefficient according to the first relational expression and a preset relational expression.

[0116] In the embodiment of the present application, the preset relationship is first derived to determine Equation 4 and Equation 5:

[0117] (Formula 4)

[0118] (Formula 5)

[0119] When the state of the battery to be tested meets the preset state conditions, the surface of the battery to be tested is approximately equipotential, that is, ,Will and Substituting into Equation 4 and Equation 5, and taking the difference between Equation 4 and Equation 5, we get Equation 6:

[0120] (Equation 6)

[0121] Furthermore, when the state of the battery to be tested meets the preset state condition, , then according to formula 6 we can get ,in, is the proportional coefficient. That is, the ohmic impedance of each region can be determined by the overall ohmic impedance of the battery and the current ratio of each region. Using the polarization curve of the battery as a whole and equations (1) and (2), the overall ohmic impedance of the battery can be identified by the least squares method. For example, in the embodiment of the present application, .

[0122] In the above application embodiment, since the current proportion of each region remains unchanged when the state of the battery to be tested meets the preset state conditions, the first relationship can be determined based on the current density and area of ​​each region, thereby improving the efficiency of estimating the contact resistance.

[0123] In one embodiment, Figure 13 As shown, the above-mentioned method for estimating the in-plane distribution of battery contact resistance further includes:

[0124] S204, determining whether the state of the battery to be tested meets preset state conditions based on the current density distribution; the preset state conditions include equipotential within the surface, each region not reaching the concentration polarization control region, and the current proportion of each region within the first-level preset current density range being the same.

[0125] In an embodiment of the present application, when the contact resistance of the battery to be tested is initially analyzed, it is necessary to determine whether the state of the battery to be tested meets the preset state conditions based on the current density distribution under the current stable operating conditions. After the stable operating conditions that meet the preset state conditions are determined through cyclic iteration, when the contact resistance of the battery to be tested is analyzed again, it can be assumed that the state of the battery to be tested meets the preset state conditions. The preset state conditions include equipotential within the surface, each region not reaching the concentration polarization control region, and the current proportion of each region within the preset current density range being the same. When the state of the battery to be tested meets the preset state conditions, the above S202 is executed.

[0126] Optionally, in the embodiment of the present application, a test polarization curve is generated according to the current density and the voltage corresponding to the current density. The polarization curves of the battery inlet voltage and outlet voltage are as follows: Figure 6 As shown, the partition polarization curve is as follows Figure 7 As shown. Thus, according to the test polarization curve, it is determined whether the state of the battery to be tested meets the preset state conditions; alternatively, the current density of each area can be input into a pre-trained state analysis model to determine whether the state of the battery to be tested meets the preset state conditions.

[0127] In the above application embodiment, whether the state of the battery to be tested meets the preset state condition is determined based on the current density distribution, thereby ensuring the estimation of the contact resistance of the battery to be tested under the preset state condition and improving the accuracy of the estimation.

[0128] In one embodiment, an implementation of the above S204 is provided, such as Figure 14 As shown, the above “determining whether the state of the battery to be tested meets the preset state condition based on the current density distribution” includes:

[0129] S601 , determining whether the state of the battery to be tested satisfies in-plane equipotential according to the overlap of the first polarization curves; the first polarization curve is determined according to the current density distribution of the battery to be tested.

[0130] In the embodiment of the present application, voltages are collected at the gas inlet and outlet positions of the battery, and a first polarization curve is generated based on the collected voltages and the current density corresponding to each voltage. The first polarization curve can be as follows: Figure 6 The battery inlet voltage and outlet voltage polarization curves shown in the figure are first polarization curves comprising an inlet voltage polarization curve and an outlet voltage polarization curve. Furthermore, the degree of overlap between the inlet voltage polarization curve and the outlet voltage polarization curve can be determined. When the degree of overlap is greater than or equal to a degree of overlap threshold, the battery under test is determined to meet in-plane equipotential requirements. When the degree of overlap is less than the degree of overlap threshold, the battery under test is determined to not meet in-plane equipotential requirements.

[0131] S602, when the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions have reached the concentration polarization control region based on the Tafel slope of the second polarization curve; the second polarization curve is determined based on the current density distribution of each region.

[0132] In the embodiment of the present application, a second polarization curve is generated according to the current density of each region, that is, Figure 7 In the partitioned polarization curve shown, under the current operating conditions, the voltage at 2A / cm2 is above 0.68V, and the polarization curve has not reached the concentration polarization region, but is still in the ohmic polarization control region. Therefore, the polarization curve can be approximately described by Equation 7:

[0133] (Equation 7)

[0134] in, is the battery voltage, is the Nernst voltage, is the current density; Used to describe activation polarization, is the Tafel slope, is the ohmic impedance.

[0135] Furthermore, Figure 7 The polarization curves in the seven regions shown are identified using the least squares method, and the identification results are shown in Table 4. It can be seen that the Tafel slopes within the seven regions are approximately equal, that is, the activation polarizations are approximately the same.

[0136] Table 4

[0137]

[0138] It should be noted that the activation polarization of a fuel cell is primarily affected by the oxygen concentration and relative humidity of the catalyst layer. The higher the oxygen concentration and the wetter the catalyst layer, the lower the activation polarization. In the embodiments of this application, a high oxygen concentration intake (60%), a high cathode stoichiometric ratio (1.8), and a high humidity (80%) are used to achieve this condition. If the Tafel slopes differ significantly, it may be necessary to modify the stable operating conditions to achieve the desired state. For example, modifying the stable operating conditions may include increasing the oxygen concentration, intake flow rate, intake pressure, or humidity.

[0139] S603 , when the state of the battery to be tested satisfies that none of the regions have reached the concentration polarization control region, determining whether the state of the battery to be tested meets a preset state condition according to a ratio of the current of each region to the current of the battery to be tested.

[0140] In the embodiment of the present application, according to the current density of each region, the ratio of the current inside each region to the overall current at each steady-state point is determined as follows: Figure 15 The current ratio of different partitions at each steady-state point of the polarization curve shown is 0.8A / cm 2 -1.5A / cm 2 Within this range, the current proportion within each partition remains almost unchanged, with the current proportion changing within 1%. The steady-state point refers to the voltage at each current density after it has been running steadily for a period of time, when the high-frequency impedance and voltage of the battery are close to stable.

[0141] It should be noted that if the current ratio within each partition within the surface cannot remain approximately unchanged, it indicates that this part of the current will be affected by concentration polarization and activation polarization, and the operating conditions need to be further optimized. This condition can be achieved by increasing the oxygen concentration, increasing the intake flow rate, and increasing the intake pressure.

[0142] In the above application embodiment, by operating the battery to be tested under stable operating conditions, the current proportion of each area within the battery surface in the medium current density area of ​​the battery to be tested remains approximately unchanged, thereby using the overall ohmic impedance and current distribution of the battery to identify the ohmic impedance of different partitions.

[0143] In one embodiment, a complete method for estimating the in-plane distribution of battery contact resistance is provided, such as Figure 16 As shown, the above method includes:

[0144] S1, operating the battery under test under stable operating conditions, and collecting the current density distribution of each region in the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test.

[0145] S2, determining whether the state of the battery to be tested satisfies in-plane equipotential according to the overlap of the first polarization curves; the first polarization curve is determined according to the current density distribution of the battery to be tested.

[0146] S3, when the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions reaches the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each region.

[0147] S4, when the state of the battery to be tested satisfies that none of the regions have reached the concentration polarization control region, determining whether the state of the battery to be tested meets a preset state condition according to a ratio of the current of each region to the current of the battery to be tested.

[0148] S5, when the state of the battery to be tested meets the preset state condition, determining a first relationship according to the current density of each region and the area of ​​each region; the preset state condition is set to match the stable operation condition.

[0149] S6. Determine a proportionality coefficient according to the first relational expression and a preset relational expression; the preset relational expression is a correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region.

[0150] S7, determining the ohmic impedance of each region according to the proportional coefficient and a preset relationship.

[0151] S8, determining the electron transfer impedance and membrane impedance of each region based on the physical characteristics of the battery to be tested.

[0152] S9, determining the contact resistance of each region based on the electron transfer impedance, the membrane impedance, and the ohmic impedance.

[0153] In the above-mentioned method for estimating the in-plane distribution of battery contact resistance, the battery to be tested is operated under stable operating conditions, and the current density distribution of each region in the battery to be tested is collected; each region is obtained by dividing according to the cathode flow field structure and the anode flow field structure of the battery to be tested; when the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each region to determine the ohmic impedance of each region, and the preset state conditions are set to match the stable operating conditions; based on the ohmic impedance of each region, the contact resistance of each region is determined. The membrane is fully hydrated by stably operating the battery at high humidity and high current, so that the membrane impedance of different regions in the surface is approximately equal. The battery to be tested is operated under stable operating conditions so that the state of the battery to be tested can meet the preset state conditions, and the ohmic impedance distribution is identified using the current density of each region under this state, which improves the accuracy of the determined ohmic impedance of each region, thereby improving the accuracy of identifying the contact resistance of the battery to be tested.

[0154] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0155] Based on the same inventive concept, embodiments of the present application also provide a device for estimating the in-plane distribution of battery contact resistance, which is used to implement the aforementioned method for estimating the in-plane distribution of battery contact resistance. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the device for estimating the in-plane distribution of battery contact resistance provided below can be found in the limitations of the method for estimating the in-plane distribution of battery contact resistance described above and will not be repeated here.

[0156] In one embodiment, Figure 17 As shown, a device for estimating the in-plane distribution of battery contact resistance is provided, comprising: an acquisition module 10, an identification module 11 and a first determination module 12, wherein:

[0157] The acquisition module 10 is used to operate the battery under test under stable operating conditions and collect the current density distribution of each region in the battery under test; each region is obtained by dividing the cathode flow field structure and the anode flow field structure of the battery under test;

[0158] An identification module 11 is configured to identify the ohmic impedance distribution according to the current density of each region and determine the ohmic impedance of each region when the state of the battery to be tested meets a preset state condition, wherein the preset state condition is set to match the stable operating condition;

[0159] The first determining module 12 is configured to determine the contact resistance of each region according to the ohmic impedance of each region.

[0160] In one embodiment, the first determining module 12 includes: a first determining unit and a second determining unit, wherein:

[0161] The first determining unit is used to determine the electron transfer impedance and membrane impedance of each region according to the physical characteristics of the battery to be tested.

[0162] The second determining unit is configured to determine the contact resistance of each region according to the electron transfer impedance, the film impedance, and the ohmic impedance.

[0163] In one embodiment, the identification module 11 includes: a third determination unit and a fourth determination unit, wherein:

[0164] The third determination unit is used to determine the proportional coefficient of the ohmic impedance of each area to the total ohmic impedance of the battery to be tested based on the current density of each area, the area of ​​each area and a preset relationship; the preset relationship is the correlation between the Tafel slope, voltage and ohmic impedance corresponding to each area.

[0165] The fourth determining unit is configured to determine the ohmic impedance of each region according to the proportional coefficient and a preset relationship.

[0166] In one embodiment, the third determining unit is specifically configured to determine a first relationship expression according to the current density of each region and the area of ​​each region; and determine a proportional coefficient according to the first relationship expression and a preset relationship expression.

[0167] In one embodiment, the above-mentioned in-plane distribution estimation device of battery contact resistance also includes: a second determination module, which is used to determine whether the state of the battery to be tested meets the preset state conditions based on the current density distribution; the preset state conditions include the same electric potential in the surface, each region has not reached the concentration polarization control region, and the current proportion of each region in the first-level preset current density range is the same.

[0168] In one embodiment, the second determining module includes: a fifth determining unit, a sixth determining unit, and a seventh determining unit, wherein:

[0169] The fifth determining unit is used to determine whether the state of the battery to be tested meets the in-plane equipotential according to the overlap of the first polarization curve; the first polarization curve is determined according to the current density distribution of the battery to be tested.

[0170] a sixth determining unit, for determining, when the state of the battery to be tested satisfies the in-plane equipotential, whether the state of the battery to be tested satisfies the condition that none of the regions reaches the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each region.

[0171] The seventh determining unit is configured to determine whether the state of the battery to be tested meets a preset state condition according to a ratio of a current in each region to a current of the battery to be tested when the state of the battery to be tested meets the condition that none of the regions reaches the concentration polarization control region.

[0172] Each module in the above-mentioned device for estimating the in-plane distribution of battery contact resistance can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0173] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 18 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store in-plane distribution estimation data of battery contact resistance. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for estimating the in-plane distribution of battery contact resistance is implemented.

[0174] Those skilled in the art will understand that Figure 18 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0175] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0176] The battery under test is operated under stable operating conditions, and the current density distribution of each region in the battery under test is collected; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0177] When the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each area to determine the ohmic impedance of each area; the preset state conditions are set to match the stable operation conditions;

[0178] Based on the ohmic impedance of each area, the contact resistance of each area is determined.

[0179] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0180] Determine the electron transfer impedance and membrane impedance of each region based on the physical characteristics of the battery to be tested;

[0181] The contact resistance of each region is determined based on the electron transfer impedance, membrane impedance, and ohmic impedance.

[0182] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0183] Determine the proportionality coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery under test based on the current density of each region, the area of ​​each region, and a preset relationship; the preset relationship is the correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region;

[0184] The ohmic impedance of each area is determined based on the proportional coefficient and the preset relationship.

[0185] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0186] Determine a first relationship based on the current density of each region and the area of ​​each region;

[0187] A proportional coefficient is determined according to the first relational expression and a preset relational expression.

[0188] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0189] Based on the current density distribution, determine whether the state of the battery to be tested meets the preset state conditions; the preset state conditions include equipotential within the surface, each region has not reached the concentration polarization control region, and the current proportion of each region within the first-level preset current density range is the same.

[0190] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0191] Determining whether the state of the battery under test satisfies the in-plane equipotential according to the overlap of the first polarization curves; the first polarization curve is determined according to the current density distribution of the battery under test;

[0192] When the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions have reached the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each region;

[0193] When the state of the battery to be tested satisfies that none of the regions reaches the concentration polarization control region, whether the state of the battery to be tested meets the preset state condition is determined according to the ratio of the current of each region to the current of the battery to be tested.

[0194] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0195] The battery under test is operated under stable operating conditions, and the current density distribution of each region in the battery under test is collected; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0196] When the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each area to determine the ohmic impedance of each area; the preset state conditions are set to match the stable operation conditions;

[0197] Based on the ohmic impedance of each area, the contact resistance of each area is determined.

[0198] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0199] Determine the electron transfer impedance and membrane impedance of each region based on the physical characteristics of the battery to be tested;

[0200] The contact resistance of each region is determined based on the electron transfer impedance, membrane impedance, and ohmic impedance.

[0201] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0202] Determine the proportionality coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery under test based on the current density of each region, the area of ​​each region, and a preset relationship; the preset relationship is the correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region;

[0203] The ohmic impedance of each area is determined based on the proportional coefficient and the preset relationship.

[0204] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0205] Determine a first relationship based on the current density of each region and the area of ​​each region;

[0206] A proportional coefficient is determined according to the first relational expression and a preset relational expression.

[0207] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0208] Based on the current density distribution, determine whether the state of the battery to be tested meets the preset state conditions; the preset state conditions include equipotential within the surface, each region has not reached the concentration polarization control region, and the current proportion of each region within the first-level preset current density range is the same.

[0209] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0210] Determining whether the state of the battery under test satisfies the in-plane equipotential according to the overlap of the first polarization curves; the first polarization curve is determined according to the current density distribution of the battery under test;

[0211] When the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions have reached the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each region;

[0212] When the state of the battery to be tested satisfies that none of the regions reaches the concentration polarization control region, whether the state of the battery to be tested meets the preset state condition is determined according to the ratio of the current of each region to the current of the battery to be tested.

[0213] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0214] The battery under test is operated under stable operating conditions, and the current density distribution of each region in the battery under test is collected; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test;

[0215] When the state of the battery to be tested meets the preset state conditions, the ohmic impedance distribution is identified according to the current density of each area to determine the ohmic impedance of each area; the preset state conditions are set to match the stable operation conditions;

[0216] Based on the ohmic impedance of each area, the contact resistance of each area is determined.

[0217] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0218] Determine the electron transfer impedance and membrane impedance of each region based on the physical characteristics of the battery to be tested;

[0219] The contact resistance of each region is determined based on the electron transfer impedance, membrane impedance, and ohmic impedance.

[0220] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0221] Determine the proportionality coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery under test based on the current density of each region, the area of ​​each region, and a preset relationship; the preset relationship is the correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region;

[0222] The ohmic impedance of each area is determined based on the proportional coefficient and the preset relationship.

[0223] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0224] Determine a first relationship based on the current density of each region and the area of ​​each region;

[0225] A proportional coefficient is determined according to the first relational expression and a preset relational expression.

[0226] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0227] Based on the current density distribution, determine whether the state of the battery to be tested meets the preset state conditions; the preset state conditions include equipotential within the surface, each region has not reached the concentration polarization control region, and the current proportion of each region within the first-level preset current density range is the same.

[0228] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0229] Determining whether the state of the battery under test satisfies the in-plane equipotential according to the overlap of the first polarization curves; the first polarization curve is determined according to the current density distribution of the battery under test;

[0230] When the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions have reached the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each region;

[0231] When the state of the battery to be tested satisfies that none of the regions reaches the concentration polarization control region, whether the state of the battery to be tested meets the preset state condition is determined according to the ratio of the current of each region to the current of the battery to be tested.

[0232] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processors (GPUs), digital signal processors (DSPs), programmable logic devices (PLCs), artificial intelligence (AI) processors, and the like.

[0233] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0234] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for estimating the in-plane distribution of battery contact resistance, characterized in that: The method comprises: Operating the battery under test under stable operating conditions, collecting current density distribution of each region in the battery under test; each region is divided according to the cathode flow field structure and the anode flow field structure of the battery under test; When the state of the battery to be tested meets a preset state condition, a proportional coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery to be tested is determined based on the current density of each region, the area of ​​each region, and a preset relationship; the preset relationship is a correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region; the ohmic impedance of each region is determined based on the proportional coefficient and the preset relationship; the preset state condition is set to match the stable operation condition; The contact resistance of each of the regions is determined based on the ohmic impedance of each of the regions.

2. The method according to claim 1, characterized in that Determining the contact resistance of each of the regions according to the ohmic impedance of each of the regions includes: Determining the electron transfer impedance and membrane impedance of each of the regions according to the physical characteristics of the battery to be tested; The contact resistance of each of the regions is determined based on the electron transfer impedance, the film impedance, and the ohmic impedance.

3. The method according to claim 1, characterized in that The stable operation condition is that the operation time under the operation conditions of high humidity, high oxygen concentration and preset current density is longer than the preset time.

4. The method according to claim 3, characterized in that The determining, based on the current density of each region, the area of ​​each region, and a preset correlation relationship, a proportional coefficient of the ohmic impedance of each region to the total ohmic impedance of the battery to be tested includes: Determining a first relationship according to the current density of each of the regions and the area of ​​each of the regions; The proportional coefficient is determined according to the first relational expression and the preset relational expression.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: According to the current density distribution, determine whether the state of the battery to be tested meets the preset state conditions; the preset state conditions include equipotential within the surface, each of the regions does not reach the concentration polarization control region, and the current proportion of each of the regions within the first-level preset current density range is the same.

6. The method according to claim 5, characterized in that The determining, based on the current density distribution, whether the state of the battery to be tested meets a preset state condition includes: determining whether the state of the battery under test satisfies in-plane equipotential according to the overlap of the first polarization curves, wherein the first polarization curve is determined according to the current density distribution of the battery under test; When the state of the battery to be tested satisfies the in-plane equipotential, determining whether the state of the battery to be tested satisfies the condition that none of the regions reaches the concentration polarization control region according to the Tafel slope of the second polarization curve; the second polarization curve is determined according to the current density distribution of each of the regions; When the state of the battery to be tested satisfies that none of the regions reaches the concentration polarization control region, whether the state of the battery to be tested meets a preset state condition is determined according to a ratio of the current of each region to the current of the battery to be tested.

7. A device for estimating the in-plane distribution of battery contact resistance, characterized in that: The device comprises: an acquisition module, configured to operate the battery under test under stable operating conditions and acquire current density distribution in each region of the battery under test; each region being divided according to the cathode flow field structure and the anode flow field structure of the battery under test; an identification module, configured to determine, when the state of the battery to be tested satisfies a preset state condition, a proportionality coefficient between the ohmic impedance of each region and the total ohmic impedance of the battery to be tested based on the current density of each region, the area of ​​each region, and a preset relationship formula, wherein the preset relationship formula is a correlation between the Tafel slope, voltage, and ohmic impedance corresponding to each region; and determine the ohmic impedance of each region based on the proportionality coefficient and the preset relationship formula; wherein the preset state condition is set to match the stable operating condition; The determination module is configured to determine the contact resistance of each of the regions according to the ohmic impedance of each of the regions.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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