A rapid determination method, device and equipment for gas production of lithium battery high-temperature storage

Abstract

The application discloses a kind of lithium battery high-temperature storage gas production rapid determination method, device and equipment, applied in lithium battery field, the method comprises: initial cell is charged to termination voltage, and the cell charged to termination voltage is delithiated, and the cell to be determined is obtained;First volume of the cell to be determined is obtained;Second volume after the cell to be determined is placed at preset temperature for a preset time period is obtained;The volume growth rate of the cell to be determined is calculated according to the first volume and the second volume, and the gas production determination data of lithium battery is obtained.The application can keep the lattice structure of the cell in high delithiation state by delithiating the cell charged to termination voltage, and maintain the positive electrode in the oxidized state at high voltage and the negative electrode in the reduced state at low voltage by charging the cell to termination voltage during the high-temperature storage stage, accelerating the gas production process of the cell during the high-temperature storage stage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lithium batteries, in particular to a rapid determination method, device and equipment for gas production of lithium batteries in high-temperature storage. BACKGROUND

[0002] Lithium batteries have the advantages of high platform voltage, high energy density, light weight, small size, small environmental pollution, etc., and are widely used in 3C intelligent terminals, energy storage, electric vehicles and other fields. Under high-temperature use state, a series of chemical reactions exist between the positive and negative electrode materials and the electrolyte of the lithium battery, which will produce gas and further cause the battery to swell, which to some extent restricts the application range of the lithium battery.

[0003] The gas in the lithium battery is mainly produced by chemical reaction between the positive and negative electrode materials and the electrolyte under high-temperature state. At present, the high-temperature storage characteristics of the positive electrode material of the lithium battery are mainly evaluated by making soft package full cells. This test method not only has a long cycle and a complex process, but also is easily affected by factors such as the different negative electrode materials used by various manufacturers, and the test results have uncertainty, which leads to obvious differences in the proportion of gas composition, indicating that the entire reaction process of gas production has changed. Therefore, how to propose a determination method for gas production of lithium batteries under high-temperature storage characteristics is a technical problem that needs to be solved by the person skilled in the art. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a rapid determination method, device and equipment for gas production of lithium batteries in high-temperature storage, which solves the problem of long determination cycle, complex process and easy interference of different negative electrode materials used by various manufacturers in the prior art.

[0005] To solve the above technical problems, the present application provides a rapid determination method for gas production of lithium batteries in high-temperature storage, comprising:

[0006] charge the initial battery cell to the termination voltage, and perform delithiation treatment on the battery cell charged to the termination voltage to obtain a battery cell to be determined;

[0007] obtain a first volume of the battery cell to be determined;

[0008] obtain a second volume of the battery cell to be determined after being placed at a preset temperature for a preset time period;

[0009] calculate the volume growth rate of the battery cell to be determined according to the first volume and the second volume to obtain gas determination data of the lithium battery.

[0010] Optionally, after the volume growth rate of the to-be-tested battery cell is calculated according to the first volume and the second volume, the gas generation measurement data of the lithium battery is obtained, and the method further comprises:

[0011] When the volume of the to-be-tested battery cell reaches a third preset volume, performing a gas chromatography test on the to-be-tested battery cell to obtain test gas generation comparison data of the lithium battery;

[0012] If the test gas generation comparison data is in a standard gas generation comparison data range, the gas generation measurement data is taken as final gas generation measurement data.

[0013] Optionally, the process of performing the delithiation treatment on the battery cell charged to the termination voltage to obtain the to-be-tested battery cell comprises:

[0014] performing a delithiation treatment on the battery cell charged to the termination voltage according to a preset delithiation amount to obtain the to-be-tested battery cell; the preset delithiation amount is a delithiation amount that can accelerate the high-temperature storage gas generation of the lithium battery and does not change the gas composition of the gas generated.

[0015] Optionally, before the process of charging the initial battery cell to the termination voltage and performing the delithiation treatment on the battery cell charged to the termination voltage to obtain the to-be-tested battery cell, the method further comprises:

[0016] performing an electrochemical setting on the selected battery cell to obtain the initial battery cell.

[0017] Optionally, when the second volume of the to-be-tested battery cell after being placed at a preset temperature for a preset time period is obtained, the method further comprises:

[0018] obtaining a capacity recovery rate and a capacity retention rate of the to-be-tested battery cell;

[0019] recording the capacity recovery rate and the capacity retention rate.

[0020] Optionally, the process of obtaining the first volume of the to-be-tested battery cell comprises:

[0021] obtaining the first volume of the to-be-tested battery cell by using a drainage method;

[0022] Correspondingly, the process of obtaining the second volume of the to-be-tested battery cell after being placed at a preset temperature for a preset time period comprises:

[0023] obtaining the second volume of the to-be-tested battery cell after being placed at the preset temperature for the preset time period by using a drainage method.

[0024] Optionally, the process of determining the preset delithiation amount in the process of performing the delithiation treatment on the battery cell charged to the termination voltage comprises:

[0025] The rapid determination of the gas production of the lithium battery under high-temperature storage is performed multiple times, and data in which the volume growth rate is greater than a growth rate threshold in the obtained final gas production determination data are selected as a final gas production determination data set;

[0026] The delithiation amounts corresponding to the final gas production determination data set are integrated to obtain a preset delithiation amount value interval.

[0027] Optionally, the initial battery cell is an initial ternary lithium battery cell.

[0028] The application further provides a rapid determination device for gas production of a lithium battery under high-temperature storage, comprising:

[0029] A to-be-determined chip acquisition module is configured to charge an initial battery cell to a termination voltage and perform delithiation processing on the battery cell charged to the termination voltage to obtain a to-be-determined battery cell.

[0030] A first volume acquisition module is configured to acquire a first volume of the to-be-determined battery cell.

[0031] A second volume acquisition module is configured to acquire a second volume of the to-be-determined battery cell after the to-be-determined battery cell is placed at a preset temperature for a preset time period.

[0032] A gas production determination data calculation module is configured to calculate a volume growth rate of the to-be-determined battery cell according to the first volume and the second volume to obtain gas production determination data of the lithium battery.

[0033] The application further provides a rapid determination device for gas production of a lithium battery under high-temperature storage, comprising:

[0034] A memory is configured to store a computer program.

[0035] A processor is configured to execute the computer program to implement the steps of the rapid determination method for gas production of a lithium battery under high-temperature storage.

[0036] It can be seen that the rapid determination method for gas production of a lithium battery under high-temperature storage provided by the application comprises charging an initial battery cell to a termination voltage, performing delithiation processing on the battery cell charged to the termination voltage to obtain a to-be-determined battery cell, acquiring a first volume of the to-be-determined battery cell, acquiring a second volume of the to-be-determined battery cell after the to-be-determined battery cell is placed at a preset temperature for a preset time period, and calculating a volume growth rate of the to-be-determined battery cell according to the first volume and the second volume to obtain gas production determination data of the lithium battery. The delithiation processing on the battery cell charged to the termination voltage can make the battery cell maintain a high delithiation state lattice structure, and the charging of the battery cell to the termination voltage in the high-temperature storage stage can make the positive electrode maintain an oxidized state at a high voltage and the negative electrode maintain a reduced state at a low voltage, thereby accelerating the gas production process of the battery cell in the high-temperature storage stage.

[0037] In addition, the present invention also provides a rapid measuring device and equipment for gas generation during high-temperature storage of lithium batteries, which also has the above-mentioned beneficial effects. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0039] Figure 1 A flowchart illustrating a rapid method for measuring gas generation during high-temperature storage of lithium batteries, provided as an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of a rapid measurement device for gas generation during high-temperature storage of lithium batteries provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of a rapid measurement device for gas generation during high-temperature storage of lithium batteries, provided as an embodiment of the present invention. Detailed Implementation

[0042] In this embodiment, under a fully charged state, the high-nickel ternary material undergoes continuous reduction of transition metal ions as lithium ions are continuously extracted. Since the oxidized state of oxygen ions overlaps with nickel and cobalt, the high-delithiation state leads to the loss of electrons by oxygen, releasing lattice oxygen and oxidizing the electrolyte, thus generating gas. Compared to cathode materials under conventional testing, the material structure in the high-delithiation state is more unstable. Due to anisotropic lattice changes, the ternary material is prone to grain boundary cracking, leading to secondary particle breakage, a rapid increase in specific surface area and interfacial side reactions, thereby accelerating the gas generation reaction.

[0043] Compared to cathode materials under conventional testing, materials in the high-delithiation state have a more unstable structure. Due to anisotropic lattice changes, ternary materials are prone to grain boundary cracking, leading to the breakage of secondary particles and accelerating the gas generation reaction. At the positive end, the chemical reaction is mainly driven by the strong oxidant (such as elemental oxygen) released by the cathode material and its highly active surface. At the negative end, as the amount of lithium intercalation increases, the negative electrode potential decreases, accelerating the reduction of the electrolyte. By controlling the amount of delithiation in the high-nickel ternary material, the potential of the cathode material can be increased, the negative electrode potential can be decreased, and thus the gas generation can be accelerated.

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Please refer to Figure 1 , Figure 1 A flowchart illustrating a rapid method for determining gas generation during high-temperature storage of a lithium battery, provided as an embodiment of the present invention. The method may include:

[0046] S101: Charge the initial cell to the termination voltage, and perform delithiation on the cell charged to the termination voltage to obtain the cell to be tested.

[0047] The execution entity in this embodiment is the processing terminal. In this embodiment, the initial battery cell is charged using a constant current and constant voltage method. When the initial battery cell is charged to the termination voltage, it undergoes delithiation treatment to obtain the battery cell to be tested. It should be noted that the termination voltage in this embodiment can be determined based on the upper charging limit voltage corresponding to the target delithiation state. This indicates that the material is in an overcharged stage. Compared to conventional testing, materials in the overcharged stage have unstable structures and are more prone to electrolyte oxidation, leading to gas production. This termination voltage is an artificially set overcharge voltage. The specific numerical index can be the upper charging limit voltage corresponding to the target delithiation state of this technical solution, representing that the material is in an unstable high-delithiation state compared to materials in conventional testing, thereby achieving rapid evaluation testing of gas production in ternary materials using this solution.

[0048] It should be noted that in this embodiment, the battery cell preparation process involves weighing a fixed amount of materials according to the following mass ratios: positive electrode material, conductive agent, dispersant, and binder, respectively, at 94.5%, 1%, 2%, and 2.5%. PVDF (polyvinylidene fluoride) is dissolved in a fixed amount of NMP (N-methylpyrrolidone), and the positive electrode material and conductive agent are added. The mixture is then placed in a mixer to homogenize the materials and prepare a uniform positive electrode slurry. The prepared positive electrode slurry is uniformly coated onto aluminum foil to form an electrode sheet, which is then dried in an oven to produce a positive electrode sheet for later use. For the negative electrode, materials are weighed in the following mass ratios: artificial graphite, dispersant, conductive agent, and binder, respectively, at 95.5%, 1%, 1.5%, and 2%. CMC (carboxymethyl cellulose) is dissolved in a fixed amount of deionized water, and the negative electrode material and conductive agent are added, followed by the binder. The mixture is placed in a mixer and mixed evenly to make a uniform negative electrode slurry. The prepared negative electrode slurry is then evenly coated onto copper foil to form an electrode sheet. The electrode sheet is then dried in an oven and prepared for use. Through winding, liquid injection, encapsulation, formation, capacity testing, aging, and sorting processes, a 0.8AH battery cell is produced.

[0049] Furthermore, to ensure that the gas generation process of the obtained battery cell remains unchanged, the above-mentioned delithiation treatment of the battery cell charged to the termination voltage to obtain the battery cell under test may include:

[0050] The battery cell charged to the termination voltage is subjected to delithiation treatment according to the preset delithiation amount to obtain the battery cell to be tested.

[0051] It should be noted that in this embodiment, the preset delithiation amount is the amount that can accelerate the gas generation during high-temperature storage of lithium batteries without changing the composition of the generated gas.

[0052] This embodiment does not limit the specific setting value of the preset delithiation amount, as long as it can accelerate the gas generation during high-temperature storage of lithium batteries and the composition of the generated gas remains unchanged. For example, the specific setting value of the preset delithiation amount can be 2, or it can be 3, or it can be 4. In this embodiment, the range of the preset delithiation amount obtained through multiple measurements can be 2 to 4. It should be further noted that in this embodiment, when the preset delithiation amount exceeds the above range, the composition of the generated gas will change, and the purpose of rapidly measuring gas generation cannot be achieved; while when the preset delithiation amount does not reach the above range, although the composition of the generated gas remains basically unchanged, the gas generation cycle does not accelerate significantly. For example, in this embodiment, taking preset delithiation amounts of 1 and 6 as examples, when the preset delithiation amount is 1, the gas generation cycle does not accelerate significantly, while when the preset delithiation amount is 6, the composition of the generated gas changes significantly. The range of preset delithiation amount proposed in this embodiment is only one implementation method for the convenience of the solution. Other preset delithiation amount values ​​that are similar to the range of preset delithiation amount in this solution, and that can accelerate the gas production cycle and, within the allowable error range, determine that the composition of the produced gas has not changed, also fall within the protection scope of this invention.

[0053] Furthermore, in order to determine the range of the delithiation amount and thus ensure that the rapid measurement method for gas generation during high-temperature storage of lithium batteries can be executed, the process of determining the preset delithiation amount in the delithiation treatment of the battery cell charged to the termination voltage may include the following steps:

[0054] Step S11: Perform rapid measurement of gas generation during high-temperature storage of lithium batteries multiple times, and select the data in the final gas generation measurement data where the volume growth rate is greater than the growth rate threshold as the final gas generation measurement data group.

[0055] It should be noted that in this embodiment, the rapid method for measuring gas production during high-temperature storage of lithium batteries is executed multiple times. Data with a volume growth rate greater than the growth rate threshold is selected, and gas chromatography is performed on the cells to be tested corresponding to the data with a volume growth rate greater than the growth rate threshold. The gas production comparison data of the gas chromatography test results that are within the standard gas production comparison data range are selected, and the gas production measurement data corresponding to the gas production comparison data at this time is taken as the final gas production measurement data set.

[0056] Step S12: Integrate the delithiation amount corresponding to the final gas production measurement data set to obtain the preset delithiation amount value range.

[0057] In this embodiment, the amount of delithiation corresponding to the gas production measurement data in the final gas production measurement data group is integrated to obtain a preset range of delithiation values.

[0058] Furthermore, to further improve the efficiency of rapid measurement of gas generation during high-temperature storage of lithium batteries, before charging the initial cell to the termination voltage and performing delithiation treatment on the cell charged to the termination voltage to obtain the cell to be tested, the following steps may be included:

[0059] The selected battery cell is electrochemically configured to obtain the initial battery cell.

[0060] In this embodiment, the selected battery cell is electrochemically configured, which may specifically include the following steps:

[0061] Let it stand for 5 minutes;

[0062] Constant current and constant voltage charging, with the current parameter set to: 1C (termination voltage V1, termination current 0.05C);

[0063] Constant current discharge, wherein the current value parameter is set to 1C, and the size of 1C is the size of the normal discharge capacity C1;

[0064] Let it stand for 5 minutes;

[0065] Constant current and constant voltage charging, with the current parameter set as: I1 (termination voltage V2, termination current I2);

[0066] Let it stand for 5 minutes.

[0067] It should be noted that in this embodiment, the initial cell is charged to the termination voltage. The termination voltage can be the upper limit voltage of the cell under test during the normal capacity grading stage, or it can be the voltage corresponding to the preset high discharge capacity. The preset high discharge capacity can be calculated by substituting into the formula:

[0068] C2 = C1 + N × M × C

[0069] Wherein, C1 is the normal discharge capacity 1C of the cell to be tested, C2 is the preset high discharge capacity, N is the amount of lithium stripping, M is the mass of the active material of the cathode material, and C is the theoretical capacity of the ternary cathode material.

[0070] Furthermore, in order to improve the accuracy of rapid measurement of gas generation during high-temperature storage of the lithium battery, the aforementioned initial cell can be an initial ternary lithium battery cell.

[0071] It should be noted that the ternary lithium battery in this embodiment is a conventional ternary battery that uses nickel salt, cobalt salt, and manganese salt as the positive electrode material. The rapid testing method in this embodiment is well-suited for ternary lithium batteries, without damaging the gas generation process or the lithium battery itself. By adjusting the amount of lithium delithiation and the voltage of the ternary lithium battery cell before the high-temperature storage test, the ternary material maintains a high-delithiation lattice structure. During the high-temperature storage stage, the positive electrode is maintained in a high-voltage oxidized state, and the negative electrode is maintained in a low-voltage reduced state through float charging. This accelerates the gas generation process of the cell during the high-temperature storage stage without changing the composition of the generated gas.

[0072] S102: Obtain the first volume of the cell to be measured.

[0073] It should be noted that in this embodiment, before the cell to be tested produces gas, the volume of the cell to be tested is measured to obtain the first volume of the cell to be tested. This first volume is then calculated with the volume measured after the cell to be tested produces gas, thereby obtaining the gas production measurement data of the lithium battery.

[0074] This embodiment does not limit the specific method for obtaining the first volume of the battery cell to be tested, as long as the first volume of the battery cell to be tested can be accurately obtained. For example, the first volume of the battery cell to be tested can be obtained by the water displacement method, or the first volume of the battery cell to be tested can be calculated by the volume formula.

[0075] S103: Obtain the second volume of the battery cell to be tested after it has been placed at a preset temperature for a preset time period.

[0076] It should be noted that in this embodiment, after the battery cell to be tested is placed at a preset temperature for a preset time period, the second volume of the battery cell to be tested at this time is obtained. The second volume of the battery cell to be tested at this time is the volume of the battery cell to be tested after gas generation.

[0077] This embodiment does not limit the preset temperature setting value, as long as the preset temperature setting value is within the high temperature range. For example, the preset temperature setting value can be 70 degrees Celsius, or it can be 75 degrees Celsius, or it can be 80 degrees Celsius. This embodiment does not limit the preset time period setting value, as long as it can detect a change in volume after gas generation in the battery cell. It should be noted that in this embodiment, the preset time period is set by the operator, and the preset time period setting value can be 7 days, or it can be 8 days.

[0078] Furthermore, to improve the functionality of the rapid measurement method for gas generation during high-temperature storage of lithium batteries, and to monitor various parameters of the cell under test, when obtaining the second volume of the cell under test after being placed at a preset temperature for a preset time period, the method may further include the following steps:

[0079] Step S21: Obtain the current capacity recovery rate and capacity retention rate of the cell to be tested.

[0080] Step S22: Record the capacity recovery rate and capacity retention rate.

[0081] S104: Calculate the volume growth rate of the cell to be tested based on the first volume and the second volume to obtain the gas production measurement data of the lithium battery.

[0082] It should be noted that in this embodiment, when calculating the volume growth rate of the cell under test based on the first volume and the second volume to obtain the gas production measurement data of the lithium battery, the first volume and the second volume can be substituted into the formula:

[0083] γ=(T2-T1) / T1

[0084] Where γ is the volume growth rate, T1 is the first volume, and T2 is the second volume.

[0085] This embodiment does not limit the specific content of the gas production measurement data of the lithium battery, as long as it can characterize the gas production capacity of the lithium battery. For example, this embodiment can directly use the calculated volume growth rate of the cell under test as the gas production measurement data of the lithium battery, or it can use the time period for the cell under test to reach the preset volume growth rate as the gas production measurement data of the lithium battery, or it can use other data that can characterize the gas production capacity of the lithium battery as the gas production measurement data of the lithium battery.

[0086] Furthermore, in order to determine that the chemical reaction occurring during the gas generation process of the lithium battery has not changed, and to improve the accuracy of rapid measurement of gas generation during high-temperature storage of lithium batteries, after calculating the volume growth rate of the cell under test based on the first volume and the second volume to obtain the gas generation measurement data of the lithium battery, the following steps may also be included:

[0087] Step S31: When the volume of the cell to be tested reaches the third preset volume, perform gas chromatography test on the cell to be tested to obtain comparative data on the gas production of the lithium battery.

[0088] It should be noted that in this embodiment, during the high-temperature storage stage of the lithium battery, the gas mainly originates from the oxidized electrolyte of the positive electrode material and the reduced electrolyte of the negative electrode material. To verify the differences in gas production among different lithium batteries and to accelerate gas production efficiency without altering the gas production principle, gas chromatography (GC) testing of the cell under test is required to obtain comparative data on the gas production of the lithium battery. By verifying the consistency between the gas composition ratio of the cell and that in conventional gas production measurements, and indicating that the gas production mechanism has not changed, it can be concluded that this method can directly and effectively accelerate gas production without altering the reaction mechanism. In this embodiment, GC testing can be directly performed on the cell under test.

[0089] Step S32: If the test gas production comparison data is within the standard gas production comparison data range, then the gas production measurement data shall be used as the final gas production measurement data.

[0090] It should be noted that the gas production comparison data obtained from the gas chromatography test of the battery cell under test in this embodiment should be consistent with the gas chromatography test results of the battery cell under test in conventional gas production determination. Conventional determination shows that in non-accelerated battery cell testing, the ratio of carbon dioxide to carbon monoxide content in the gas composition is between 1.3 and 1.95. Therefore, if the ratio of carbon dioxide to carbon monoxide content in the gas composition of the rapid determination of gas production during high-temperature storage of lithium batteries remains within the range of 1.3-1.95, it can be considered that the method has not changed the gas production reaction process of the battery cell, and the gas production measurement data can be used as the final gas production measurement data. In this embodiment, the standard gas production comparison data range is the range corresponding to the gas chromatography test results of the battery cell under test in conventional gas production determination. In this embodiment, the ratio of carbon dioxide to carbon monoxide content in the gas composition is between 1.3 and 1.95.

[0091] Furthermore, to improve the accuracy of obtaining the volume of the battery cell to be tested, the above-mentioned method for obtaining the first volume of the battery cell to be tested may include:

[0092] The first volume of the battery cell to be tested is obtained using the water displacement method.

[0093] Accordingly, obtaining the second volume of the battery cell under test after being placed at a preset temperature for a preset time period may include:

[0094] The second volume of the battery cell under test is obtained by using the water displacement method after it has been placed at a preset temperature for a preset time period.

[0095] The rapid measurement method for gas generation in lithium batteries during high-temperature storage provided by this invention includes charging an initial cell to a termination voltage and performing a delithiation process on the cell charged to the termination voltage to obtain a cell to be tested; obtaining a first volume of the cell to be tested; obtaining a second volume of the cell to be tested after being placed at a preset temperature for a preset time period; calculating the volume growth rate of the cell to be tested based on the first volume and the second volume to obtain gas generation measurement data of the lithium battery. This invention, by performing a delithiation process on the cell charged to the termination voltage, enables the cell to maintain a highly delithiated crystal structure, and during the high-temperature storage stage, by charging the cell to the termination voltage, maintains the positive electrode in a high-voltage oxidized state and the negative electrode in a low-voltage reduced state, thus accelerating the gas generation process of the cell during high-temperature storage. Furthermore, by determining a preset delithiation amount range that does not alter the reaction process of the cell under test and accelerates gas production, and by using the preset delithiation amount within this range to delitherate the cell charged to the termination voltage, it is ensured that the gas production process of the cell under test remains unchanged, thus guaranteeing the execution of the rapid measurement method for gas production during high-temperature storage of lithium batteries. By electrochemically setting the selected cell to obtain an initial cell, the efficiency of the rapid measurement of gas production during high-temperature storage of lithium batteries can be improved. By obtaining the current capacity recovery rate and capacity retention rate of the cell under test, the functionality of the rapid measurement method for gas production during high-temperature storage of lithium batteries is enhanced, enabling the monitoring of various parameters of the cell under test. Gas chromatography testing of the cell under test confirms that the chemical reaction during gas production in the lithium battery has not changed, improving the accuracy of the rapid measurement of gas production during high-temperature storage of lithium batteries. Using the water displacement method to obtain the first and second volumes of the cell under test improves the accuracy of obtaining the cell's volume. By setting the test object to a ternary lithium battery, the above measurement method can be better adapted.

[0096] To make the present invention easier to understand, it may specifically include the following steps:

[0097] Step S1: Select a ternary lithium battery cell and perform electrochemical settings to obtain an initial ternary lithium battery cell.

[0098] Step S2: Charge the initial ternary lithium battery cell to the upper limit voltage of the normal capacity grading stage of the cell to be tested, and perform delithiation treatment on the cell to be tested to obtain the cell to be tested. The delithiation amount is selected from 2 to 4.

[0099] Step S3: Using the water displacement method, test the first volume of the cell under test at this point. Then, place the cell under test in a 70℃ oven for a 14-day storage test. During this period, the volume is tested every seven days, and the second volume is recorded multiple times, i.e., calculate the volume growth rate over 7 days and 14 days. After the test is completed, float charge the cell under test to the voltage corresponding to the preset high discharge capacity, and then place the cell in the 70℃ oven again for storage testing.

[0100] Step S4: When the volume of the cell to be tested reaches the third preset volume, perform gas chromatography test on the cell to be tested to obtain the test gas production comparison data of the lithium battery. If the test gas production comparison data is within the standard gas production comparison data range, then the gas production measurement data is taken as the final gas production measurement data.

[0101] The rapid measurement device for gas generation during high-temperature storage of lithium batteries provided in the embodiments of the present invention will be described below. The rapid measurement device for gas generation during high-temperature storage of lithium batteries described below can be referred to in correspondence with the rapid measurement method for gas generation during high-temperature storage of lithium batteries described above.

[0102] Please refer to the details. Figure 2 , Figure 2 A schematic diagram of a rapid measurement device for gas generation during high-temperature storage of lithium batteries provided in this embodiment of the invention may include:

[0103] The chip acquisition module 100 is used to charge the initial cell to the termination voltage and perform delithiation on the cell charged to the termination voltage to obtain the cell to be tested.

[0104] The first volume acquisition module 200 is used to acquire the first volume of the battery cell to be measured.

[0105] The second volume acquisition module 300 is used to acquire the second volume of the battery cell to be tested after it has been placed at a preset temperature for a preset time period.

[0106] The gas production measurement data calculation module 400 is used to calculate the volume growth rate of the cell to be tested based on the first volume and the second volume, so as to obtain the gas production measurement data of the lithium battery.

[0107] Furthermore, based on the above embodiments, the rapid measurement device for gas generation during high-temperature storage of lithium batteries may further include:

[0108] The test gas production comparison data acquisition module is used to perform gas chromatography test on the battery cell under test when the volume of the battery cell under test reaches the third preset volume, and obtain the test gas production comparison data of the lithium battery.

[0109] The final gas production measurement data acquisition module is used to take the gas production measurement data as the final gas production measurement data if the test gas production comparison data is within the standard gas production comparison data range.

[0110] Furthermore, based on the above embodiments, the chip acquisition module 100 may include:

[0111] The chip acquisition unit is used to perform delithiation processing on the cell charged to the termination voltage according to a preset delithiation amount to obtain the cell to be tested; the preset delithiation amount is a delithiation amount that can accelerate the gas generation of lithium battery at high temperature storage without changing the composition of the generated gas.

[0112] Furthermore, based on the above embodiments, the rapid measurement device for gas generation during high-temperature storage of lithium batteries may further include:

[0113] An electrochemical setting module is used to perform electrochemical settings on the selected battery cell to obtain the initial battery cell.

[0114] Furthermore, based on the above embodiments, the rapid measurement device for gas generation during high-temperature storage of lithium batteries may further include:

[0115] The capacity recovery rate and capacity retention rate acquisition module is used to acquire the current capacity recovery rate and capacity retention rate of the cell under test;

[0116] The recording module is used to record the capacity recovery rate and the capacity retention rate.

[0117] Furthermore, based on the above embodiments, the first volume acquisition module 200 may include:

[0118] The first volume acquisition unit is used to acquire the first volume of the battery cell to be tested using the water displacement method;

[0119] Accordingly, the second volume acquisition module 300 may include:

[0120] The second volume acquisition unit is used to acquire the second volume of the battery cell to be tested after it has been placed at the preset temperature for the preset time period using the water displacement method.

[0121] Furthermore, based on any of the above embodiments, the process of determining the preset delithiation amount in the chip acquisition unit to be measured may include:

[0122] The final gas production measurement data set acquisition subunit is used to perform rapid measurement of gas production during high-temperature storage of the lithium battery multiple times, and selects the data in the obtained final gas production measurement data in which the volume growth rate is greater than the growth rate threshold as the final gas production measurement data set.

[0123] A preset delithiation amount range acquisition subunit is used to integrate and process the delithiation amount corresponding to the final gas production measurement data set to obtain the preset delithiation amount range.

[0124] Furthermore, based on the above embodiments, the initial battery cell in the chip acquisition module 100 to be tested can be an initial ternary lithium battery cell.

[0125] It should be noted that the order of the modules, units, and sub-units in the aforementioned rapid measurement device for gas generation during high-temperature storage of lithium batteries can be changed without affecting the logic.

[0126] The rapid measurement device for gas generation during high-temperature storage of lithium batteries provided in this invention includes a chip acquisition module 100 for charging an initial cell to a termination voltage and performing delithiation on the cell charged to the termination voltage to obtain the cell to be measured. A first volume acquisition module 200 acquires the first volume of the cell to be measured, and a second volume acquisition module 300 acquires the second volume of the cell after it has been placed at a preset temperature for a preset time period. A gas generation measurement data calculation module 400 calculates the volume growth rate of the cell to be measured based on the first and second volumes to obtain the gas generation measurement data of the lithium battery. This invention, by performing delithiation on the cell charged to the termination voltage, enables the cell to maintain a highly delithiated crystal structure. Furthermore, during the high-temperature storage stage, by charging the cell to the termination voltage, the positive electrode is maintained in a high-voltage oxidized state, and the negative electrode is maintained in a low-voltage reduced state, thus accelerating the gas generation process during high-temperature storage. Furthermore, by determining a preset delithiation amount range that does not alter the reaction process of the cell under test and accelerates gas production, and by using the preset delithiation amount within this range to delitherate the cell charged to the termination voltage, it is ensured that the gas production process of the cell under test remains unchanged, thus guaranteeing the execution of the rapid measurement method for gas production during high-temperature storage of lithium batteries. By electrochemically setting the selected cell to obtain an initial cell, the efficiency of the rapid measurement of gas production during high-temperature storage of lithium batteries can be improved. By obtaining the current capacity recovery rate and capacity retention rate of the cell under test, the functionality of the rapid measurement method for gas production during high-temperature storage of lithium batteries is enhanced, enabling the monitoring of various parameters of the cell under test. Gas chromatography testing of the cell under test confirms that the chemical reaction during gas production in the lithium battery has not changed, improving the accuracy of the rapid measurement of gas production during high-temperature storage of lithium batteries. Using the water displacement method to obtain the first and second volumes of the cell under test improves the accuracy of obtaining the cell's volume. By setting the test object to a ternary lithium battery, the above measurement method can be better adapted.

[0127] The rapid measurement device for gas generation during high-temperature storage of lithium batteries provided in the embodiments of the present invention will be described below. The rapid measurement device for gas generation during high-temperature storage of lithium batteries described below can be referred to in correspondence with the rapid measurement method for gas generation during high-temperature storage of lithium batteries described above.

[0128] Please refer to Figure 3 , Figure 3 A schematic diagram of a rapid measurement device for gas generation during high-temperature storage of lithium batteries, provided in an embodiment of the present invention, may include:

[0129] Memory 10 is used to store computer programs;

[0130] The processor 20 is used to execute a computer program to implement the above-mentioned rapid measurement method for gas generation during high-temperature storage of lithium batteries.

[0131] The memory 10, processor 20, and communication interface 31 all communicate with each other through the communication bus 32.

[0132] In this embodiment of the invention, the memory 10 is used to store one or more programs. The programs may include program code, which includes computer operation instructions. In this embodiment, the memory 10 may store programs for implementing the following functions:

[0133] The initial cell is charged to the termination voltage, and the cell charged to the termination voltage is subjected to delithiation to obtain the cell to be tested.

[0134] Obtain the first volume of the battery cell to be tested;

[0135] Obtain the second volume of the battery cell to be tested after it has been placed at a preset temperature for a preset time period;

[0136] The volume growth rate of the cell under test is calculated based on the first volume and the second volume to obtain the gas production measurement data of the lithium battery.

[0137] In one possible implementation, the memory 10 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function; and the data storage area may store data created during use.

[0138] Furthermore, memory 10 may include read-only memory and random access memory, providing instructions and data to the processor. A portion of the memory may also include NVRAM. The memory stores operating systems and operating instructions, executable modules, or data structures, or subsets thereof, or extended sets thereof, wherein the operating instructions may include various operating instructions for implementing various operations. The operating system may include various system programs for implementing various basic tasks and handling hardware-based tasks.

[0139] Processor 20 can be a central processing unit (CPU), an application-specific integrated circuit, a digital signal processor, a field-programmable gate array, or other programmable logic device. Processor 20 can be a microprocessor or any conventional processor. Processor 20 can call programs stored in memory 10.

[0140] Communication interface 31 can be an interface for the communication module, used to connect with other devices or systems.

[0141] Of course, it should be noted that, Figure 3 The structure shown does not constitute a limitation on the rapid measurement device for gas generation during high-temperature storage of lithium batteries in the embodiments of this application. In practical applications, the rapid measurement device for gas generation during high-temperature storage of lithium batteries may include devices with... Figure 3 More or fewer components as shown, or combinations of certain components.

[0142] The following describes the computer-readable storage medium provided in the embodiments of the present invention. The computer-readable storage medium described below can be referred to in correspondence with the rapid determination method for gas generation during high-temperature storage of lithium batteries described above.

[0143] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for rapid determination of gas generation during high-temperature storage of lithium batteries.

[0144] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0145] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0146] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0147] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0148] The present invention provides a detailed description of a rapid method, apparatus, and device for measuring gas generation during high-temperature storage of lithium batteries. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A rapid method for determining gas generation during high-temperature storage of lithium batteries, characterized in that, include: The initial battery cell is charged to the termination voltage, and the battery cell charged to the termination voltage is subjected to delithiation to obtain the battery cell to be tested. Obtain the first volume of the battery cell to be tested; Obtain the second volume of the battery cell to be tested after it has been placed at a preset temperature for a preset time period; The volume growth rate of the cell under test is calculated based on the first volume and the second volume to obtain the gas production measurement data of the lithium battery. The process of delithiating the battery cell charged to the termination voltage to obtain the battery cell to be tested includes: The battery cell charged to the termination voltage is subjected to delithiation treatment according to a preset delithiation amount to obtain the battery cell to be tested. The preset delithiation amount is the amount of delithiation that can accelerate the gas generation during high-temperature storage of lithium batteries without changing the composition of the generated gas.

2. The rapid method for determining gas generation during high-temperature storage of lithium batteries according to claim 1, characterized in that, After calculating the volume growth rate of the cell under test based on the first volume and the second volume to obtain the gas production measurement data of the lithium battery, the method further includes: When the volume of the cell to be tested reaches the third preset volume, the cell to be tested is subjected to gas chromatography test to obtain the test gas production comparison data of the lithium battery. If the test gas production comparison data is within the standard gas production comparison data range, then the gas production measurement data will be used as the final gas production measurement data.

3. The rapid method for determining gas generation during high-temperature storage of lithium batteries according to claim 1, characterized in that, Before charging the initial cell to the termination voltage and performing a lithium removal process on the cell charged to the termination voltage to obtain the cell to be tested, the method further includes: The selected battery cell is electrochemically configured to obtain the initial battery cell.

4. The rapid method for determining gas generation during high-temperature storage of lithium batteries according to claim 1, characterized in that, When obtaining the second volume of the battery cell under test after being placed at a preset temperature for a preset time period, the method further includes: Obtain the current capacity recovery rate and capacity retention rate of the cell under test; The capacity recovery rate and the capacity retention rate are recorded.

5. The rapid method for determining gas generation during high-temperature storage of lithium batteries according to claim 1, characterized in that, Obtaining the first volume of the battery cell to be tested includes: The first volume of the battery cell to be tested is obtained using the water displacement method; Accordingly, obtaining the second volume of the battery cell to be tested after being placed at a preset temperature for a preset time period includes: The second volume of the battery cell to be tested after being placed at the preset temperature for the preset time period is obtained by using the water displacement method.

6. The rapid method for determining gas generation during high-temperature storage of lithium batteries according to any one of claims 1 to 5, characterized in that, The process of determining the preset delithiation amount in the delithiation treatment of the battery cell charged to the termination voltage includes: The rapid measurement of gas production during high-temperature storage of the lithium battery was performed multiple times, and the data in the final gas production measurement data in which the volume growth rate was greater than the growth rate threshold were selected as the final gas production measurement data group. The delithiation amount corresponding to the final gas production measurement data set is integrated and processed to obtain a preset delithiation amount value range.

7. The rapid method for determining gas generation during high-temperature storage of lithium batteries according to claim 1, characterized in that, The initial cell is an initial ternary lithium battery cell.

8. A rapid measuring device for gas generation during high-temperature storage of lithium batteries, characterized in that, include: The chip acquisition module is used to charge the initial cell to the termination voltage and perform delithiation on the cell charged to the termination voltage to obtain the cell to be tested. The first volume acquisition module is used to acquire the first volume of the battery cell to be tested. The second volume acquisition module is used to acquire the second volume of the battery cell to be tested after it has been placed at a preset temperature for a preset time period. The gas production measurement data calculation module is used to calculate the volume growth rate of the cell under test based on the first volume and the second volume, and obtain the gas production measurement data of the lithium battery. The chip acquisition module includes: The chip acquisition unit is used to perform lithium removal processing on the cell charged to the termination voltage according to a preset lithium removal amount to obtain the cell to be tested. The preset delithiation amount is the amount of delithiation that can accelerate the gas generation during high-temperature storage of lithium batteries without changing the composition of the generated gas.

9. A rapid measuring device for gas generation during high-temperature storage of lithium batteries, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the rapid measurement method for gas generation during high-temperature storage of lithium batteries as described in any one of claims 1 to 7.

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