Method and device for determining proportion of battery mixed negative electrode failure, and electronic equipment

Abstract

The application provides a battery mixed negative electrode failure proportion determination method and device and electronic equipment, and relates to the technical field of batteries. The method comprises the following steps: processing a cycled battery to be tested to produce a button-type half battery, performing charge and discharge testing on the button-type half battery, and obtaining a voltage capacity curve during charging; normalizing the voltage capacity curve according to the total charging capacity, and determining a first test capacity proportion of a first target voltage interval and a second test capacity proportion of a second target voltage interval; based on the first test capacity proportion and the second test capacity proportion, performing iteration in a database respectively to determine a corresponding target graphite proportion and a target silicon-carbon proportion; and according to the target graphite proportion, the target silicon-carbon proportion, an initial graphite proportion and an initial silicon-carbon proportion of the battery to be tested, determining a failure proportion of graphite and a failure proportion of silicon-carbon in the battery to be tested. Thus, the absolute capacity difference is eliminated, and the accuracy of the failure proportion determination is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method, apparatus and electronic device for determining the failure ratio of a hybrid negative electrode in a battery. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density and long cycle life, have been widely used in new energy vehicles, portable electronic devices, and other fields. As the demand for extended battery life in end products continues to increase, developing high-specific-capacity anode materials has become one of the core directions of lithium-ion battery research and development. Silicon-carbon materials, due to their high specific capacity, are often mixed with graphite as anodes; however, silicon-based materials often experience severe volume expansion during charging and discharging, which can easily lead to electrode structure damage and capacity decay.

[0003] In related technologies, failure analysis of hybrid anodes typically employs methods such as scanning electron microscopy (SEM) morphology analysis and impedance testing. However, these methods can only qualitatively determine the overall degradation phenomenon of the anode, such as active material shedding and solid-electrolyte interphase (SEI) thickening, and cannot quantify the individual capacity degradation contributions of silicon-carbon and graphite. Therefore, accurately determining the failure ratio of the hybrid anode is crucial. Summary of the Invention

[0004] This application provides a method, apparatus, and electronic device for determining the failure ratio of a battery's hybrid negative electrode.

[0005] According to a first aspect of this application, a method for determining the failure ratio of a hybrid negative electrode in a battery is provided, the method comprising: The cycled battery under test is processed to produce a coin cell, wherein the battery under test contains a silicon-carbon-graphite hybrid negative electrode sheet. The button cell half-cell is subjected to charge and discharge tests, and the voltage-capacity curve during the charging process is obtained, wherein the voltage-capacity curve includes the total charging capacity. The voltage capacity curve is normalized based on the total charging capacity, and the first test capacity ratio of the first target voltage range and the second test capacity ratio of the second target voltage range are determined. The first target voltage range is the graphite delithiation voltage range, and the second target voltage range is the silicon-carbon delithiation voltage range. Based on the first test capacity ratio and the second test capacity ratio, the database is traversed to determine the corresponding target graphite ratio and target silicon-carbon ratio. Based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery under test, the failure ratio of graphite and the failure ratio of silicon-carbon in the battery under test are determined.

[0006] Optionally, the step of performing a charge-discharge test on the coin cell and obtaining the voltage-capacity curve during the charging process includes: The coin cell is discharged to the lower discharge limit voltage at a first constant current rate. The coin cell is charged to the upper charging voltage at a second constant current rate. During the process of charging the coin cell to the upper limit of the charging voltage, the voltage and capacity values ​​of the coin cell at each moment are recorded to generate a voltage-capacity curve.

[0007] Optionally, the step of iterating through the database based on the first test capacity ratio and the second test capacity ratio to determine the corresponding target graphite ratio and target silicon-carbon ratio includes: If a first standard capacity percentage that is the same as the first test capacity percentage is found in the database, the graphite percentage corresponding to the first standard capacity percentage is determined as the target graphite percentage. If no first standard capacity percentage with the same value as the first test capacity percentage is found in the database, the second standard capacity percentage and the third standard capacity percentage that are closest to the first test capacity percentage are processed to determine the target graphite ratio, wherein the second standard capacity percentage is less than the first test capacity percentage and the first test capacity percentage is less than the third standard capacity percentage. If a fourth standard capacity percentage that is the same as the second test capacity percentage is found in the database, the silicon-carbon ratio corresponding to the fourth standard capacity percentage is determined as the target silicon-carbon ratio. If no fourth standard capacity percentage with the same value as the second test capacity percentage is found in the database, the fifth and sixth standard capacity percentages that are closest to the second test capacity percentage are processed to determine the target silicon-carbon ratio, wherein the fifth standard capacity percentage is less than the second test capacity percentage, and the second test capacity percentage is less than the sixth standard capacity percentage.

[0008] Optionally, the step of processing the second and third standard capacity ratios that are closest to the first test capacity ratio value to determine the target graphite ratio includes: Based on the first difference between the first test capacity percentage and the second standard capacity percentage, the second difference between the third standard capacity percentage and the second standard capacity percentage, the third difference between the first graphite ratio and the second graphite ratio, and the first graphite ratio, a target graphite ratio is determined, wherein the first graphite ratio is the graphite ratio corresponding to the second standard capacity percentage in the database, and the second graphite ratio is the graphite ratio corresponding to the third standard capacity percentage in the database. The process of processing the fifth and sixth standard capacity ratios, which are closest to the second test capacity ratio value, to determine the target silicon-carbon ratio includes: The target silicon-carbon ratio is determined based on the fourth difference between the second test capacity ratio and the fifth standard capacity ratio, the fifth difference between the sixth standard capacity ratio and the fifth standard capacity ratio, the sixth difference between the first silicon-carbon ratio and the second silicon-carbon ratio, and the first silicon-carbon ratio. The first silicon-carbon ratio is the silicon-carbon ratio corresponding to the fifth standard capacity ratio in the database, and the second silicon-carbon ratio is the silicon-carbon ratio corresponding to the sixth standard capacity ratio in the database.

[0009] Optionally, determining the failure ratio of graphite and the failure ratio of silicon carbon in the battery under test based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio, and the initial silicon-carbon ratio of the battery under test includes: Determine the seventh difference between the initial graphite ratio and the target graphite ratio of the battery under test, and the eighth difference between the initial silicon-carbon ratio and the target silicon-carbon ratio; The ratio between the seventh difference and the initial graphite ratio is determined as the failure ratio of graphite in the battery under test. The ratio between the eighth difference and the initial silicon-carbon ratio is determined as the failure ratio of silicon-carbon in the battery under test.

[0010] Optionally, the process of processing the cycled battery to be tested to fabricate a coin cell includes: The cycled battery under test was disassembled to obtain a negative electrode sheet containing a silicon-carbon-graphite hybrid electrode. A coin cell half-cell is assembled by using a pretreated negative electrode as the working electrode and a lithium metal sheet as the counter electrode.

[0011] Optionally, before determining the corresponding target graphite ratio and target silicon-carbon ratio by iterating through the database based on the first test capacity ratio and the second test capacity ratio, the method further includes: Negative electrode sheets with different graphite and silicon-carbon ratios were assembled into standard coin cell half-cells, and charge-discharge tests were performed on them respectively. During the charging process of each standard coin cell, the voltage and normalized capacity curves of each standard coin cell are recorded. The voltage and normalized capacity curves of each standard coin cell are processed to determine a first mapping relationship between each graphite ratio and normalized capacity percentage, and a second mapping relationship between each silicon-carbon ratio and normalized capacity percentage. Store the first mapping relationship and the second mapping relationship in the database.

[0012] According to a second aspect of this application, an apparatus for determining the failure ratio of a battery hybrid negative electrode is provided, comprising: A processing module is used to process the cycled battery under test to produce a coin cell, wherein the battery under test includes a silicon-carbon-graphite hybrid negative electrode sheet. The acquisition module is used to perform charge and discharge tests on the button cell half battery and acquire the voltage-capacity curve during the charging process, wherein the voltage-capacity curve includes the total charging capacity. The first determining module is used to normalize the voltage capacity curve according to the total charging capacity, and determine the first test capacity ratio of the first target voltage range and the second test capacity ratio of the second target voltage range, wherein the first target voltage range is the graphite delithiation voltage range and the second target voltage range is the silicon-carbon delithiation voltage range. The traversal module is used to traverse the database based on the first test capacity ratio and the second test capacity ratio to determine the corresponding target graphite ratio and target silicon-carbon ratio. The second determining module is used to determine the failure ratio of graphite and the failure ratio of silicon carbon in the battery under test based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery under test.

[0013] Optionally, the acquisition module is specifically used for: The coin cell is discharged to the lower discharge limit voltage at a first constant current rate. The coin cell is charged to the upper charging voltage at a second constant current rate. During the process of charging the coin cell to the upper limit of the charging voltage, the voltage and capacity values ​​of the coin cell at each moment are recorded to generate a voltage-capacity curve.

[0014] Optionally, the traversal module includes: The first determining unit is used to determine the graphite ratio corresponding to the first standard capacity ratio as the target graphite ratio when a first standard capacity ratio that is the same as the first test capacity ratio is found in the database. The second determining unit is used to process the second standard capacity ratio and the third standard capacity ratio that are closest to the first test capacity ratio in the database when no first standard capacity ratio is found that is the same as the first test capacity ratio, in order to determine the target graphite ratio, wherein the second standard capacity ratio is less than the first test capacity ratio and the first test capacity ratio is less than the third standard capacity ratio. The third determining unit is used to determine the silicon-carbon ratio corresponding to the fourth standard capacity ratio as the target silicon-carbon ratio when a fourth standard capacity ratio with the same as the second test capacity ratio is found in the database. The fourth determining unit is used to process the fifth and sixth standard capacity percentages that are closest to the second test capacity percentage in the database when no fourth standard capacity percentage with the same value as the second test capacity percentage is found in the database, so as to determine the target silicon-carbon ratio, wherein the fifth standard capacity percentage is less than the second test capacity percentage and the second test capacity percentage is less than the sixth standard capacity percentage.

[0015] Optionally, the second determining unit is specifically used for: Based on the first difference between the first test capacity percentage and the second standard capacity percentage, the second difference between the third standard capacity percentage and the second standard capacity percentage, the third difference between the first graphite ratio and the second graphite ratio, and the first graphite ratio, a target graphite ratio is determined, wherein the first graphite ratio is the graphite ratio corresponding to the second standard capacity percentage in the database, and the second graphite ratio is the graphite ratio corresponding to the third standard capacity percentage in the database. The fourth determining unit is specifically used for: The target silicon-carbon ratio is determined based on the fourth difference between the second test capacity ratio and the fifth standard capacity ratio, the fifth difference between the sixth standard capacity ratio and the fifth standard capacity ratio, the sixth difference between the first silicon-carbon ratio and the second silicon-carbon ratio, and the first silicon-carbon ratio. The first silicon-carbon ratio is the silicon-carbon ratio corresponding to the fifth standard capacity ratio in the database, and the second silicon-carbon ratio is the silicon-carbon ratio corresponding to the sixth standard capacity ratio in the database.

[0016] Optionally, the second determining module is specifically used for: Determine the seventh difference between the initial graphite ratio and the target graphite ratio of the battery under test, and the eighth difference between the initial silicon-carbon ratio and the target silicon-carbon ratio; The ratio between the seventh difference and the initial graphite ratio is determined as the failure ratio of graphite in the battery under test. The ratio between the eighth difference and the initial silicon-carbon ratio is determined as the failure ratio of silicon-carbon in the battery under test.

[0017] Optionally, the processing module is specifically used for: The cycled battery under test was disassembled to obtain a negative electrode sheet containing a silicon-carbon-graphite hybrid electrode. A coin cell half-cell is assembled by using a pretreated negative electrode as the working electrode and a lithium metal sheet as the counter electrode.

[0018] Optionally, the traversal module is further configured to: Negative electrode sheets with different graphite and silicon-carbon ratios were assembled into standard coin cell half-cells, and charge-discharge tests were performed on them respectively. During the charging process of each standard coin cell, the voltage and normalized capacity curves of each standard coin cell are recorded. The voltage and normalized capacity curves of each standard coin cell are processed to determine a first mapping relationship between each graphite ratio and normalized capacity percentage, and a second mapping relationship between each silicon-carbon ratio and normalized capacity percentage. Store the first mapping relationship and the second mapping relationship in the database.

[0019] According to a third aspect of this application, an electronic device is provided, comprising: a processor and a memory storing computer program instructions; the processor, when executing the computer program instructions, implements any of the above-described methods for determining the failure ratio of a mixed negative electrode in a battery.

[0020] According to a fourth aspect of this application, a computer-readable storage medium is provided, on which computer program instructions are stored, wherein when the computer program instructions are executed by a processor, the method for determining the failure ratio of any of the above-described battery hybrid negative electrodes is implemented.

[0021] In summary, the method and apparatus for determining the failure ratio of the hybrid negative electrode of the battery provided in this application have at least the following beneficial effects: by processing the battery to be tested after cycling to obtain a coin cell, and performing charge-discharge tests to obtain voltage-capacity curves, and then normalizing the process, the test capacity ratios corresponding to the delithiation voltage ranges of graphite and silicon-carbon can be determined. By traversing the database, the target ratios of graphite and silicon-carbon can be determined. Combined with the initial graphite ratio and the initial silicon-carbon ratio, the failure ratios of graphite and silicon-carbon in the hybrid negative electrode can be determined. Thus, the absolute capacity difference is eliminated through normalization, making the determination of the component failure ratio more accurate and reliable. At the same time, since it does not depend on the weight of the negative electrode sheet, it avoids complex weighing processes, simplifies the testing process, shortens the testing cycle, and provides a data foundation for the subsequent optimization and analysis of the hybrid negative electrode of the battery. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart illustrating a method for determining the failure ratio of a hybrid negative electrode in a battery, provided as an embodiment of this application; Figure 2 A structural diagram of a device for determining the failure ratio of a hybrid negative electrode in a battery, provided for an embodiment of this application; Figure 3 This is a structural diagram of an electronic device provided as an embodiment of the present application. Detailed Implementation

[0024] To make the above and other features and advantages of this application clearer, the application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art, and are exemplary only, not restrictive.

[0025] In the following description, numerous specific details are set forth to provide a thorough understanding of this application. However, it will be apparent to those skilled in the art that the specific details are not required to practice this application. In other instances, well-known steps or operations have not been described in detail to avoid obscuring this application.

[0026] The method for determining the failure ratio of the hybrid negative electrode of a battery provided in this application embodiment can be executed by the device for determining the failure ratio of the hybrid negative electrode of a battery provided in this application embodiment, and the device can be configured in an electronic device.

[0027] refer to Figure 1 This application provides a method for determining the failure ratio of a hybrid negative electrode in a battery, the method comprising: Step 101: Process the cycled battery to be tested to produce a coin cell, wherein the battery to be tested contains a silicon-carbon-graphite hybrid negative electrode sheet.

[0028] Among these methods, lithium-ion batteries that have undergone a certain period of cycle aging can be safely disassembled, and their negative electrode sheets can be used to prepare coin cells that can be used for electrochemical testing, so as to carry out subsequent analysis and processing.

[0029] Optionally, the battery to be tested after cycling can be disassembled to obtain a silicon-carbon-graphite hybrid negative electrode sheet. The pretreated negative electrode sheet can be used as the working electrode and the lithium metal sheet as the counter electrode to assemble a coin cell.

[0030] For example, after a certain number of cycles, the battery under test can be disassembled in an argon-filled glove box to obtain the silicon-carbon / graphite hybrid negative electrode sheet inside the battery. The positive electrode active material, separator fragments, or residual electrolyte adhering to the surface of the negative electrode sheet can be removed. Then, the negative electrode sheet can be immersed in dimethyl carbonate (DMC) solvent to remove residual lithium salts and unstable solid electrolyte interphase films from its surface. After vacuum drying, the negative electrode sheet can be punched into a suitable size disc. The pretreated negative electrode sheet is then used as the working electrode, and a lithium metal sheet is used as the counter electrode to assemble a coin cell.

[0031] It should be noted that the above examples are merely illustrative and should not be construed as limiting the processing of the battery under test to obtain a button cell in the embodiments of this application.

[0032] Step 102: Perform a charge-discharge test on the button cell and obtain the voltage-capacity curve during the charging process, wherein the voltage-capacity curve includes the total charging capacity.

[0033] In the process of charging and discharging a coin cell battery, it is usually first discharged to allow the negative electrode active material to be fully lithium-intercalated, and then charged to allow the negative electrode active material to be delithiated. The voltage and capacity values ​​at each moment during the charging process are recorded to generate the corresponding voltage-capacity curve.

[0034] Optionally, the coin cell can be discharged to the lower discharge limit voltage at a first constant current rate, and then charged to the upper charging limit voltage at a second constant current rate. During the charging process, the voltage and capacity values ​​of the coin cell are recorded at each moment to generate a voltage-capacity curve.

[0035] The first constant current multiplier and the second constant current multiplier may be the same or different, and this application does not limit this.

[0036] In addition, the 1C current can be calculated based on the initial weight of the active material of the negative electrode. The first constant current ratio can be 0.1C, 0.2C, etc., and the second constant current ratio can be 0.1C, 0.2C, etc. This application does not limit this.

[0037] In addition, the discharge lower limit can be understood as the cutoff voltage for complete lithium intercalation of the negative electrode active material, such as 0.005V, or other values; the charging upper limit can be understood as the cutoff voltage for complete delithiation of the negative electrode active material, such as 2V, or other values.

[0038] In addition, the capacity value can be understood as the cumulative capacity value charged into the coin cell at each moment during the charging process. This capacity value can be automatically collected and recorded using a battery charge and discharge tester, or it can be obtained by any other acceptable method. This application does not limit this.

[0039] Then, the charging voltage value at each moment can be fitted with the cumulative capacity value to generate a voltage-capacity curve, which can characterize the charging voltage value and the corresponding capacity value at each moment during the charging process.

[0040] Step 103: Normalize the voltage-capacity curve based on the total charging capacity, and determine the first test capacity percentage of the first target voltage range and the second test capacity percentage of the second target voltage range, wherein the first target voltage range is the graphite delithiation voltage range and the second target voltage range is the silicon-carbon delithiation voltage range.

[0041] The total charging capacity can be understood as the final cumulative charging capacity of a coin cell when it is charged to its upper limit voltage during the charging process.

[0042] In addition, the ratio of the capacity value in the voltage-capacity curve to the total charging capacity can be used as the normalized capacity value to obtain the normalized voltage and normalized capacity curves. This can effectively eliminate the interference of absolute capacity differences caused by the weight deviation of active materials and the different degree of cycle decay of coin cells, and preserve the capacity distribution characteristics.

[0043] It is understandable that during the charging process of a coin cell, the delithiation reaction at the negative electrode typically occurs sequentially with increasing voltage. For example, when the charging voltage reaches approximately 0.07V, graphite begins to undergo delithiation. As charging continues, when the voltage reaches 0.2V, silicon-carbon begins delithiation. When the voltage reaches 0.4V, the silicon-carbon delithiation reaction is essentially complete. The voltage then continues to increase until the upper charging limit is reached, at which point the charging process ends. Based on these delithiation characteristics, the main delithiation range for graphite is 0.07V-0.2V, and the main delithiation range for silicon-carbon is 0.2V-0.4V. Therefore, the first target voltage range is 0.07V-0.2V, the second target range is 0.2V-0.4V, and so on. This application does not impose any limitations on this.

[0044] It is understandable that if a mixed negative electrode with different systems is used, the range of the target voltage range can be adjusted according to the actual delithiation electrochemical characteristics, and this application does not limit this.

[0045] Furthermore, the first test capacity percentage can be the difference between the normalized capacity value at the end of the first target voltage range and the normalized capacity value at the beginning. This can be understood as the percentage of capacity release occurring within the first target voltage range, i.e., the graphite characteristic platform, during the entire delithiation process, relative to the total delithiation capacity. This value characterizes the contribution of graphite materials to the total capacity of the hybrid anode. Similarly, the second test capacity percentage can be the difference between the normalized capacity value at the end of the second target voltage range and the normalized capacity value at the beginning. This can also be understood as the percentage of capacity release occurring within the second target voltage range, i.e., the silicon-carbon characteristic platform, during the entire delithiation process, relative to the total delithiation capacity. This value characterizes the contribution of silicon-carbon materials to the total capacity of the hybrid anode.

[0046] Step 104: Based on the first test capacity ratio and the second test capacity ratio, traverse the database to determine the corresponding target graphite ratio and target silicon-carbon ratio.

[0047] The database stores the mapping relationship between different graphite ratios, silicon-carbon ratios and normalized capacity ratios. Therefore, in this embodiment, after determining the first test capacity ratio and the second test capacity ratio corresponding to the battery to be tested, the first test capacity ratio and the second test capacity ratio can be used as indexes to traverse and search the database to determine the target graphite ratio corresponding to the first test capacity ratio and the target silicon-carbon ratio corresponding to the second test capacity ratio.

[0048] Optionally, if a first standard capacity percentage with the same value as the first test capacity percentage is found in the database, the graphite percentage corresponding to the first standard capacity percentage is determined as the target graphite percentage. If no first standard capacity percentage with the same value as the first test capacity percentage is found in the database, the second standard capacity percentage and the third standard capacity percentage that are closest to the first test capacity percentage can be processed to determine the target graphite percentage, wherein the second standard capacity percentage is less than the first test capacity percentage, and the first test capacity percentage is less than the third standard capacity percentage.

[0049] Understandably, the above method enables direct mapping between test data and standard data in the database. Furthermore, when no matching first standard capacity percentage exists in the database, two adjacent standard capacity percentages that are closest to the first test capacity percentage and satisfy the condition that the second standard capacity percentage is less than the third standard capacity percentage are selected and processed. This solves the problem of incomplete overlap between test data and standard data in the database, effectively preventing data matching failures. This allows any test capacity percentage to be used to determine the corresponding target graphite ratio from the database, effectively improving the accuracy and reliability of target graphite ratio determination.

[0050] Optionally, if no first standard capacity ratio with the same first test capacity ratio is found in the database, the target graphite ratio can be determined based on the first difference between the first test capacity ratio and the second standard capacity ratio, the second difference between the third standard capacity ratio and the second standard capacity ratio, the third difference between the first graphite ratio and the second graphite ratio, and the first graphite ratio.

[0051] Among them, the first graphite ratio is the graphite ratio corresponding to the second standard capacity ratio in the database, and the second graphite ratio is the graphite ratio corresponding to the third standard capacity ratio in the database.

[0052] For example, if the first test capacity ratio is Qgr1, and the closest second and third standard capacity ratios in the database are Qgr2 and Qgr3 respectively, and the first graphite ratio is P1 and the second graphite ratio is P2, then the first difference is Qgr2-Qgr1, the second difference is Qgr3-Qgr2, and the third difference is P2-P1. We can then determine the ratio of the first difference to the second difference, and sum the product of this ratio and the third difference with the first graphite ratio. The result is the target graphite ratio. This application does not limit this aspect.

[0053] Therefore, in this embodiment of the application, the target graphite ratio can be determined by processing the adjacent standard capacity ratio data in the database, thereby significantly reducing the matching error, ensuring the calculation accuracy of the target graphite ratio, and providing a reliable data foundation for the subsequent quantification of graphite failure ratio.

[0054] Optionally, if a fourth standard capacity percentage with the same value as the second test capacity percentage is found in the database, the silicon-carbon ratio corresponding to the fourth standard capacity percentage is determined as the target silicon-carbon ratio. If no fourth standard capacity percentage with the same value as the second test capacity percentage is found in the database, the fifth and sixth standard capacity percentages that are closest to the second test capacity percentage are processed to determine the target silicon-carbon ratio, wherein the fifth standard capacity percentage is less than the second test capacity percentage, and the second test capacity percentage is less than the sixth standard capacity percentage.

[0055] Understandably, by using both precise and approximate matching methods, a direct mapping between test data and standard data in the database is achieved, while also resolving the issue of incomplete overlap between test data and standard data. This effectively avoids data matching failures and allows any test capacity percentage to be determined by the database, thus significantly improving the accuracy and reliability of the target silicon-carbon ratio determination.

[0056] Optionally, the target silicon-carbon ratio can be determined based on the fourth difference between the second test capacity ratio and the fifth standard capacity ratio, the fifth difference between the sixth standard capacity ratio and the fifth standard capacity ratio, the sixth difference between the first silicon-carbon ratio and the second silicon-carbon ratio, and the first silicon-carbon ratio.

[0057] The first silicon-carbon ratio is the silicon-carbon ratio corresponding to the fifth standard capacity ratio in the database, and the second silicon-carbon ratio is the silicon-carbon ratio corresponding to the sixth standard capacity ratio in the database.

[0058] For example, if the second test capacity ratio is Qsi1, and the closest fifth and sixth standard capacity ratios in the database are Qsi2 and Qsi3 respectively, the first silicon-carbon ratio is P3, and the second graphite ratio is P4, then the fourth difference is Qsi2-Qsi1, the fifth difference is Qsi3-Qsi2, and the sixth difference is P4-P3. We can then first determine the ratio of the fourth difference to the fifth difference, and then sum the product of this ratio and the sixth difference with the first silicon-carbon ratio. The result is the target silicon-carbon ratio. This application does not limit this aspect.

[0059] Therefore, in this embodiment of the application, the target silicon-carbon ratio can be determined by processing the adjacent standard capacity ratio data in the database, thereby significantly reducing the matching error, ensuring the calculation accuracy of the target silicon-carbon ratio, and providing a reliable data foundation for the subsequent quantification of silicon-carbon failure ratio.

[0060] Optionally, negative electrode sheets with different graphite and silicon-carbon ratios can be assembled into standard coin cells in advance and charged and discharged separately. Then, during the charging process of each standard coin cell, the voltage and normalized capacity curves of each standard coin cell can be recorded, and the voltage and normalized capacity curves of each standard coin cell can be processed to determine the first mapping relationship between each graphite ratio and the normalized capacity ratio, and the second mapping relationship between each silicon-carbon ratio and the normalized capacity ratio. The first and second mapping relationships can then be stored in a database.

[0061] In this process, standard mixed negative electrode sheets with different graphite and silicon carbon contents can be prepared according to gradient ratios to cover the ratio range as much as possible. Then, each standard mixed negative electrode sheet can be used as the working electrode and a lithium metal sheet as the counter electrode to assemble a standard coin cell in an argon glove box.

[0062] Then, a unified charge and discharge test can be performed on all standard coin cells, and the voltage value and cumulative charging capacity value of each standard coin cell can be recorded at a preset frequency to obtain a complete voltage-capacity curve and total charging capacity.

[0063] The voltage-capacity curves of each standard coin cell can then be normalized to determine the normalized capacity value at each voltage point, thereby determining the normalized capacity percentages of the graphite delithiation range and the silicon-carbon delithiation range. A first mapping relationship between the graphite ratio and the graphite normalized capacity percentage, and a second mapping relationship between the silicon-carbon ratio and the silicon-carbon normalized capacity percentage, can then be established, and all first and second mapping relationships can be stored in a database.

[0064] Therefore, in this embodiment of the application, the gradient ratio design can ensure that the database can cover the common ratio range of hybrid negative electrodes in practical applications, avoid data gaps during matching, and at the same time, the use of unified test conditions ensures the accuracy and comparability of the normalized capacity ratio, so that the mapping relationship can accurately reflect the characteristics of graphite, silicon-carbon ratio and capacity contribution, providing a solid data foundation for determining the failure ratio of the battery to be tested.

[0065] Step 105: Determine the failure rate of graphite and silicon carbon in the battery under test based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery under test.

[0066] The failure ratio can be understood as the proportion of active material loss, and can be used to characterize the degree of loss of graphite and silicon-carbon active materials in the battery under test due to failure, etc., which is not limited in this application. Optionally, the seventh difference between the initial graphite ratio and the target graphite ratio, and the eighth difference between the initial silicon-carbon ratio and the target silicon-carbon ratio of the battery under test can be determined first. Then, the ratio of the seventh difference to the initial graphite ratio can be determined as the failure ratio of graphite in the battery under test, and the ratio of the eighth difference to the initial silicon-carbon ratio can be determined as the failure ratio of silicon-carbon in the battery under test.

[0067] For example, if the initial graphite ratio of the battery to be tested is 91% and the target graphite ratio is 88%, then the seventh difference is 3%, and the corresponding graphite failure ratio is the ratio of 3% to 91%, which is 3.29%.

[0068] For example, if the initial silicon-carbon ratio of the battery to be tested is 9% and the target silicon-carbon ratio is 7%, then the difference is 2%, and the corresponding silicon-carbon failure ratio is the ratio of 2% to 9%, which is 22.2%.

[0069] It should be noted that the above examples are merely illustrative and should not be construed as limiting the initial graphite ratio, target graphite ratio, initial silicon-carbon ratio, target silicon-carbon ratio, seventh difference, eighth difference, graphite failure ratio, and silicon-carbon failure ratio in the embodiments of this application.

[0070] Therefore, in this embodiment, the difference between the initial ratio and the target ratio reflects the absolute degree of material capacity decay, and the ratio of the difference to the initial ratio is used to convert it into a relative failure ratio. This preserves the actual magnitude of decay while enabling a horizontal comparison of the degree of failure under different initial ratio systems. After determining the failure ratios of graphite and silicon-carbon, the causes of failure can be analyzed more accurately. Based on the failure ratios, targeted improvements can be made to silicon-carbon materials or adjustments can be made to the particle size distribution of graphite, providing direction for subsequent battery optimization. This can significantly shorten the R&D cycle and reduce R&D costs.

[0071] It is understood that the embodiments of this application can quantify the failure ratio of silicon-carbon-graphite, distinguishing the failure contributions of silicon-carbon and graphite. Furthermore, traditional half-cell testing typically requires precise acquisition of the active material weight to calculate the specific capacity. However, the quality of the negative electrode sheet after cycling undergoes uncontrollable changes due to factors such as SEI film thickening and lithium deposition, rendering traditional testing methods ineffective. This application fundamentally avoids dependence on the precise initial weight of the electrode sheet through normalization processing. Even when the electrode sheet's quality state is unknown, accurate analysis of the mixed negative electrode component ratio can still be achieved. Simultaneously, since complex weighing and related calculations of the post-cycling electrode sheet are unnecessary, the testing process is significantly simplified, and the analysis cycle is greatly shortened. In addition, this application can output precisely quantified graphite-silicon-carbon failure data, such as the specific value of the silicon-carbon ratio decreasing from the initial value to the current value, and the precise results of the relative failure ratio. This provides direct and quantitative guidance for negative electrode material formulation optimization and failure mechanism research, thereby significantly improving R&D efficiency and targeting.

[0072] In this embodiment, the cycled battery to be tested can be processed to produce a coin cell, wherein the battery to be tested includes a silicon-carbon-graphite hybrid negative electrode. The coin cell is then subjected to charge-discharge testing, and the voltage-capacity curve during the charging process is obtained. The voltage-capacity curve includes the total charging capacity. The voltage-capacity curve is then normalized based on the total charging capacity, and the first test capacity percentage of the first target voltage range and the second test capacity percentage of the second target voltage range are determined. The first target voltage range is the graphite delithiation voltage range, and the second target voltage range is the silicon-carbon delithiation voltage range. Based on the first test capacity percentage and the second test capacity percentage, the database is traversed to determine the corresponding target graphite ratio and target silicon-carbon ratio. Then, based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery to be tested, the failure ratio of graphite and the failure ratio of silicon-carbon in the battery to be tested are determined. Therefore, by processing the cycled test battery to obtain a coin cell, and then conducting charge-discharge tests to obtain voltage-capacity curves, the test capacity ratios corresponding to the delithiation voltage ranges of graphite and silicon-carbon can be determined after normalization. By traversing the database, the target proportions of graphite and silicon-carbon can be determined. Combined with the initial graphite and silicon-carbon proportions, the failure ratios of graphite and silicon-carbon in the hybrid negative electrode can be determined. Thus, the absolute capacity difference is eliminated through normalization, making the determination of the component failure ratio more accurate and reliable. At the same time, since it does not rely on the weight of the negative electrode sheet, it avoids complex weighing processes, simplifies the testing process, shortens the testing cycle, and provides a data foundation for the subsequent optimization and analysis of the hybrid negative electrode.

[0073] According to this application, a device 200 for determining the failure ratio of a mixed negative electrode in a battery is provided, such as... Figure 2 As shown, the device includes a processing module 210, an acquisition module 220, a first determination module 230, a traversal module 240, and a second determination module 250.

[0074] The processing module 210 is used to process the cycled battery to be tested in order to produce a coin cell, wherein the battery to be tested includes a silicon-carbon-graphite hybrid negative electrode sheet.

[0075] The acquisition module 220 is used to perform charge and discharge tests on the coin cell half-cell and acquire the voltage-capacity curve during the charging process, wherein the voltage-capacity curve includes the total charging capacity.

[0076] The first determining module 230 is used to normalize the voltage capacity curve according to the total charging capacity, and determine the first test capacity ratio of the first target voltage range and the second test capacity ratio of the second target voltage range, wherein the first target voltage range is the graphite delithiation voltage range and the second target voltage range is the silicon-carbon delithiation voltage range.

[0077] The traversal module 240 is used to traverse the database based on the first test capacity ratio and the second test capacity ratio to determine the corresponding target graphite ratio and target silicon-carbon ratio.

[0078] The second determining module 250 is used to determine the failure ratio of graphite and the failure ratio of silicon carbon in the battery under test based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery under test.

[0079] Optionally, the acquisition module 220 is specifically used for: The coin cell is discharged to the lower discharge limit voltage at a first constant current rate. The coin cell is charged to the upper charging voltage at a second constant current rate. During the process of charging the coin cell to the upper limit of the charging voltage, the voltage and capacity values ​​of the coin cell at each moment are recorded to generate a voltage-capacity curve.

[0080] Optionally, the traversal module 240 includes: The first determining unit is used to determine the graphite ratio corresponding to the first standard capacity ratio as the target graphite ratio when a first standard capacity ratio that is the same as the first test capacity ratio is found in the database. The second determining unit is used to process the second standard capacity ratio and the third standard capacity ratio that are closest to the first test capacity ratio in the database when no first standard capacity ratio is found that is the same as the first test capacity ratio, in order to determine the target graphite ratio, wherein the second standard capacity ratio is less than the first test capacity ratio and the first test capacity ratio is less than the third standard capacity ratio. The third determining unit is used to determine the silicon-carbon ratio corresponding to the fourth standard capacity ratio as the target silicon-carbon ratio when a fourth standard capacity ratio with the same as the second test capacity ratio is found in the database. The fourth determining unit is used to process the fifth and sixth standard capacity percentages that are closest to the second test capacity percentage in the database when no fourth standard capacity percentage with the same value as the second test capacity percentage is found in the database, so as to determine the target silicon-carbon ratio, wherein the fifth standard capacity percentage is less than the second test capacity percentage and the second test capacity percentage is less than the sixth standard capacity percentage.

[0081] Optionally, the second determining unit is specifically used for: Based on the first difference between the first test capacity percentage and the second standard capacity percentage, the second difference between the third standard capacity percentage and the second standard capacity percentage, the third difference between the first graphite ratio and the second graphite ratio, and the first graphite ratio, a target graphite ratio is determined, wherein the first graphite ratio is the graphite ratio corresponding to the second standard capacity percentage in the database, and the second graphite ratio is the graphite ratio corresponding to the third standard capacity percentage in the database. The fourth determining unit is specifically used for: The target silicon-carbon ratio is determined based on the fourth difference between the second test capacity ratio and the fifth standard capacity ratio, the fifth difference between the sixth standard capacity ratio and the fifth standard capacity ratio, the sixth difference between the first silicon-carbon ratio and the second silicon-carbon ratio, and the first silicon-carbon ratio. The first silicon-carbon ratio is the silicon-carbon ratio corresponding to the fifth standard capacity ratio in the database, and the second silicon-carbon ratio is the silicon-carbon ratio corresponding to the sixth standard capacity ratio in the database.

[0082] Optionally, the second determining module 250 is specifically used for: Determine the seventh difference between the initial graphite ratio and the target graphite ratio of the battery under test, and the eighth difference between the initial silicon-carbon ratio and the target silicon-carbon ratio; The ratio between the seventh difference and the initial graphite ratio is determined as the failure ratio of graphite in the battery under test. The ratio between the eighth difference and the initial silicon-carbon ratio is determined as the failure ratio of silicon-carbon in the battery under test.

[0083] Optionally, the processing module 210 is specifically used for: The cycled battery under test was disassembled to obtain a negative electrode sheet containing a silicon-carbon-graphite hybrid electrode. A coin cell half-cell is assembled by using a pretreated negative electrode as the working electrode and a lithium metal sheet as the counter electrode.

[0084] Optionally, the traversal module 240 is further configured to: Negative electrode sheets with different graphite and silicon-carbon ratios were assembled into standard coin cell half-cells, and charge-discharge tests were performed on them respectively. During the charging process of each standard coin cell, the voltage and normalized capacity curves of each standard coin cell are recorded. The voltage and normalized capacity curves of each standard coin cell are processed to determine a first mapping relationship between each graphite ratio and normalized capacity percentage, and a second mapping relationship between each silicon-carbon ratio and normalized capacity percentage. Store the first mapping relationship and the second mapping relationship in the database.

[0085] The device for determining the failure ratio of the hybrid negative electrode in a battery provided in this application can first process the cycled battery to be tested to produce a coin cell, wherein the battery to be tested contains a silicon-carbon-graphite hybrid negative electrode sheet. Then, the coin cell is subjected to charge-discharge tests, and the voltage-capacity curve during the charging process is obtained. The voltage-capacity curve includes the total charging capacity. Then, the voltage-capacity curve is normalized according to the total charging capacity, and the first test capacity ratio of the first target voltage range and the second test capacity ratio of the second target voltage range are determined. The first target voltage range is the graphite delithiation voltage range, and the second target voltage range is the silicon-carbon delithiation voltage range. Then, based on the first test capacity ratio and the second test capacity ratio, the database is traversed to determine the corresponding target graphite ratio and target silicon-carbon ratio. Finally, based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery to be tested, the failure ratio of graphite and the failure ratio of silicon-carbon in the battery to be tested are determined. Therefore, by processing the cycled test battery to obtain a coin cell, and then conducting charge-discharge tests to obtain voltage-capacity curves, the test capacity ratios corresponding to the delithiation voltage ranges of graphite and silicon-carbon can be determined after normalization. By traversing the database, the target proportions of graphite and silicon-carbon can be determined. Combined with the initial graphite and silicon-carbon proportions, the failure ratios of graphite and silicon-carbon in the hybrid negative electrode can be determined. Thus, the absolute capacity difference is eliminated through normalization, making the determination of the component failure ratio more accurate and reliable. At the same time, since it does not rely on the weight of the negative electrode sheet, it avoids complex weighing processes, simplifies the testing process, shortens the testing cycle, and provides a data foundation for the subsequent optimization and analysis of the hybrid negative electrode.

[0086] It should be understood that the specific features, operations, and details described herein with respect to the methods of this application can also be similarly applied to the apparatus and system of this application, or vice versa. Furthermore, each step of the methods of this application described above can be performed by a corresponding component or unit of the apparatus or system of this application.

[0087] It should be understood that the various modules / units of the device of this application can be implemented wholly or partially through software, hardware, firmware, or a combination thereof. Each module / unit can be embedded in the processor of the electronic device in hardware or firmware form or independent of the processor, or it can be stored in the memory of the electronic device in software form for the processor to call to execute the operation of each module / unit. Each module / unit can be implemented as an independent component or module, or two or more modules / units can be implemented as a single component or module.

[0088] like Figure 3As shown, this application provides an electronic device 300, which includes a processor 301 and a memory 302 storing computer program instructions. The processor 301 executes the computer program instructions to implement the steps of the method for determining the mixed negative electrode failure ratio of a battery as described above. This electronic device 300 can be broadly categorized as a server, terminal, or any other electronic device with the necessary computing and / or processing capabilities.

[0089] In one embodiment, the electronic device 300 may include a processor, memory, network interface, communication interface, etc., connected via a system bus. The processor of the electronic device 300 can be used to provide necessary computing, processing, and / or control capabilities. The memory of the electronic device 300 may include non-volatile storage media and internal memory. The non-volatile storage media may store an operating system, computer programs, etc. The internal memory can provide an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface and communication interface of the electronic device 300 can be used to connect and communicate with external devices via a network. When the computer program is executed by the processor, it performs the steps of the method of this application.

[0090] This application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the above-described method for determining the failure ratio of the hybrid negative electrode of a battery.

[0091] Those skilled in the art will understand that the method steps of this application can be performed by a computer program instructing related hardware, such as electronic device 300 or a processor. The computer program can be stored in a non-transitory computer-readable storage medium, and its execution causes the steps of this application to be performed. Depending on the context, any reference herein to memory, storage, or other media may include non-volatile or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0092] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for determining the failure ratio of a hybrid negative electrode in a battery, characterized in that, include: The cycled battery under test is processed to produce a coin cell, wherein the battery under test contains a silicon-carbon-graphite hybrid negative electrode sheet. The button cell half-cell is subjected to charge and discharge tests, and the voltage-capacity curve during the charging process is obtained, wherein the voltage-capacity curve includes the total charging capacity. The voltage capacity curve is normalized based on the total charging capacity, and the first test capacity ratio of the first target voltage range and the second test capacity ratio of the second target voltage range are determined. The first target voltage range is the graphite delithiation voltage range, and the second target voltage range is the silicon-carbon delithiation voltage range. Based on the first test capacity ratio and the second test capacity ratio, the database is traversed to determine the corresponding target graphite ratio and target silicon-carbon ratio. Based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery under test, the failure ratio of graphite and the failure ratio of silicon-carbon in the battery under test are determined.

2. The method as described in claim 1, characterized in that, The step of performing charge-discharge tests on the coin cell half-cell and obtaining the voltage-capacity curve during the charging process includes: The coin cell is discharged to the lower discharge limit voltage at a first constant current rate. The coin cell is charged to the upper charging voltage at a second constant current rate. During the process of charging the coin cell to the upper limit of the charging voltage, the voltage and capacity values ​​of the coin cell at each moment are recorded to generate a voltage-capacity curve.

3. The method as described in claim 1, characterized in that, The step of determining the corresponding target graphite ratio and target silicon-carbon ratio by iterating through the database based on the first test capacity ratio and the second test capacity ratio includes: If a first standard capacity percentage that is the same as the first test capacity percentage is found in the database, the graphite percentage corresponding to the first standard capacity percentage is determined as the target graphite percentage. If no first standard capacity percentage with the same value as the first test capacity percentage is found in the database, the second standard capacity percentage and the third standard capacity percentage that are closest to the first test capacity percentage are processed to determine the target graphite ratio, wherein the second standard capacity percentage is less than the first test capacity percentage and the first test capacity percentage is less than the third standard capacity percentage. If a fourth standard capacity percentage that is the same as the second test capacity percentage is found in the database, the silicon-carbon ratio corresponding to the fourth standard capacity percentage is determined as the target silicon-carbon ratio. If no fourth standard capacity percentage with the same value as the second test capacity percentage is found in the database, the fifth and sixth standard capacity percentages that are closest to the second test capacity percentage are processed to determine the target silicon-carbon ratio, wherein the fifth standard capacity percentage is less than the second test capacity percentage, and the second test capacity percentage is less than the sixth standard capacity percentage.

4. The method as described in claim 3, characterized in that, The step of processing the second and third standard capacity ratios that are closest to the first test capacity ratio value to determine the target graphite ratio includes: Based on the first difference between the first test capacity percentage and the second standard capacity percentage, the second difference between the third standard capacity percentage and the second standard capacity percentage, the third difference between the first graphite ratio and the second graphite ratio, and the first graphite ratio, a target graphite ratio is determined, wherein the first graphite ratio is the graphite ratio corresponding to the second standard capacity percentage in the database, and the second graphite ratio is the graphite ratio corresponding to the third standard capacity percentage in the database. The process of processing the fifth and sixth standard capacity ratios, which are closest to the second test capacity ratio value, to determine the target silicon-carbon ratio includes: The target silicon-carbon ratio is determined based on the fourth difference between the second test capacity ratio and the fifth standard capacity ratio, the fifth difference between the sixth standard capacity ratio and the fifth standard capacity ratio, the sixth difference between the first silicon-carbon ratio and the second silicon-carbon ratio, and the first silicon-carbon ratio. The first silicon-carbon ratio is the silicon-carbon ratio corresponding to the fifth standard capacity ratio in the database, and the second silicon-carbon ratio is the silicon-carbon ratio corresponding to the sixth standard capacity ratio in the database.

5. The method as described in claim 1, characterized in that, The step of determining the failure ratio of graphite and the failure ratio of silicon carbon in the battery under test based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio, and the initial silicon-carbon ratio of the battery under test includes: Determine the seventh difference between the initial graphite ratio and the target graphite ratio of the battery under test, and the eighth difference between the initial silicon-carbon ratio and the target silicon-carbon ratio; The ratio between the seventh difference and the initial graphite ratio is determined as the failure ratio of graphite in the battery under test. The ratio between the eighth difference and the initial silicon-carbon ratio is determined as the failure ratio of silicon-carbon in the battery under test.

6. The method as described in claim 1, characterized in that, The process of processing the cycled test battery to fabricate a coin cell includes: The cycled battery under test was disassembled to obtain a negative electrode sheet containing a silicon-carbon-graphite hybrid electrode. A coin cell half-cell is assembled by using a pretreated negative electrode as the working electrode and a lithium metal sheet as the counter electrode.

7. The method as described in claim 1, characterized in that, Before determining the corresponding target graphite ratio and target silicon-carbon ratio by iterating through the database based on the first test capacity ratio and the second test capacity ratio, the method further includes: Negative electrode sheets with different graphite and silicon-carbon ratios were assembled into standard coin cell half-cells, and charge-discharge tests were performed on them respectively. During the charging process of each standard coin cell, the voltage and normalized capacity curves of each standard coin cell are recorded. The voltage and normalized capacity curves of each standard coin cell are processed to determine a first mapping relationship between each graphite ratio and normalized capacity percentage, and a second mapping relationship between each silicon-carbon ratio and normalized capacity percentage. Store the first mapping relationship and the second mapping relationship in the database.

8. A device for determining the failure ratio of a battery hybrid negative electrode, characterized in that, include: A processing module is used to process the cycled battery under test to produce a coin cell, wherein the battery under test includes a silicon-carbon-graphite hybrid negative electrode sheet. The acquisition module is used to perform charge and discharge tests on the button cell half battery and acquire the voltage-capacity curve during the charging process, wherein the voltage-capacity curve includes the total charging capacity. The first determining module is used to normalize the voltage capacity curve according to the total charging capacity, and determine the first test capacity ratio of the first target voltage range and the second test capacity ratio of the second target voltage range, wherein the first target voltage range is the graphite delithiation voltage range and the second target voltage range is the silicon-carbon delithiation voltage range. The traversal module is used to traverse the database based on the first test capacity ratio and the second test capacity ratio to determine the corresponding target graphite ratio and target silicon-carbon ratio. The second determining module is used to determine the failure ratio of graphite and the failure ratio of silicon carbon in the battery under test based on the target graphite ratio, the target silicon-carbon ratio, the initial graphite ratio and the initial silicon-carbon ratio of the battery under test.

9. An electronic device, characterized in that, The electronic device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, it implements the method for determining the failure ratio of the hybrid negative electrode of the battery as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the method for determining the failure ratio of the hybrid negative electrode of a battery as described in any one of claims 1-7.

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