Battery material screening method and device, terminal and computer readable storage medium

Abstract

The invention provides a battery material screening method and device, a terminal and a computer readable storage medium, and the method comprises the steps: obtaining preset side reaction accumulated electric quantity corresponding to each cycle index after a plurality of candidate battery materials are charged and discharged in a target electric quantity interval through a preset cycle index; the preset side reaction accumulated electric quantity is the total electric quantity consumed by the internal side reaction after the battery is charged and discharged for each cycle number; the target electric quantity interval is a proper subset of the electric quantity interval in which the battery is completely charged and discharged; and determining the candidate battery material corresponding to the preset side reaction accumulated electric quantity meeting the preset requirement as a target battery material based on the preset side reaction accumulated electric quantity corresponding to each candidate battery material under the same preset condition. The target electric quantity interval is smaller than the electric quantity interval in which the battery is completely charged and discharged, so that the data acquisition time is shortened, and the target battery material is quickly screened.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a method, device, electronic terminal and computer-readable storage medium for screening battery materials. Background Art

[0002] Lithium-ion batteries have the advantages of small size, light weight, no memory effect, high energy density and cycle life, and are widely used in mobile electronic devices, new energy vehicles, aerospace, energy storage and other fields. Batteries will experience material loss during use, and the material loss conditions in different batteries are different, so it is necessary to screen the batteries to obtain batteries that meet performance requirements. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a method, device, electronic terminal and computer-readable storage medium for screening battery materials, which can quickly screen and obtain battery materials that meet the requirements.

[0004] In a first aspect, the present application provides a method for screening battery materials, comprising: Obtaining the preset side reaction cumulative power corresponding to each number of cycles of multiple candidate battery materials after each number of cycles of charge and discharge within the target power range; the preset side reaction cumulative power is the total power consumed by the internal side reactions of the battery after each number of cycles of charge and discharge; the target power range is a true subset of the power range of the battery when it is fully charged and discharged; Based on the preset side reaction accumulated electricity corresponding to each candidate battery material under the same preset conditions, the candidate battery material corresponding to the preset side reaction accumulated electricity that meets the preset requirements is determined as the target battery material.

[0005] Compared to obtaining the preset side reaction cumulative electricity corresponding to each number of cycles of each candidate battery material within the battery's complete charge and discharge electricity range, in the technical solution of the embodiment of the present application, the preset side reaction cumulative electricity corresponding to each number of cycles of each candidate battery material within the target electricity range is obtained, and the target electricity range is smaller than the battery's complete charge and discharge electricity range, thereby shortening the data collection time, and comparing and screening the preset side reaction cumulative electricity of each candidate battery material under the same preset conditions to obtain the target battery material that meets the preset requirements, thereby achieving rapid screening of the target battery material.

[0006] In some embodiments, the target power range is [A, B], the power range for fully charging and discharging the battery is [0, 100%], the value of A is greater than 0 and less than 100%, and the value of B is 100%.

[0007] In the technical solution of the embodiment of the present application, the higher the battery power, the higher the battery voltage, and the stronger the preset side reaction occurring in the same time period. This improves the accuracy of the preset side reaction cumulative power data and helps to speed up the screening rate of battery materials.

[0008] In some embodiments, the target power A in the target power interval ranges from [80%, 98%].

[0009] In the technical solution of the embodiment of the present application, when the value range of the target power A in the target power interval is [80%, 98%], it helps to speed up the screening rate of battery materials.

[0010] In some embodiments, obtaining the preset side reaction accumulated power corresponding to each number of cycles of charge and discharge of multiple candidate battery materials in a target power range after the preset number of cycles includes: Obtaining the charge and discharge capacities corresponding to each number of cycles of multiple candidate battery materials after they have been charged and discharged for a preset number of cycles within a target power range; The preset side reaction quantity corresponding to each cycle number is calculated based on the charge and discharge quantity corresponding to each cycle; The preset side reaction electrical quantities corresponding to the current cycle number and all historical cycle numbers before the current cycle number are added together to obtain the preset side reaction cumulative electrical quantity corresponding to the current cycle number.

[0011] In the technical solution of the embodiment of the present application, by obtaining the charge and discharge amounts corresponding to each cycle number of the candidate battery within the target power range, the data collection time is shortened, and the data acquisition time of the preset side reaction cumulative power corresponding to each cycle number is accelerated, which helps to speed up the screening of battery materials.

[0012] In some embodiments, obtaining the charge and discharge capacities corresponding to each number of cycles of a plurality of candidate battery materials after they have been charged and discharged for a preset number of cycles within a target power range includes: Using a first rate to charge and discharge each candidate battery material respectively; the value range of the first rate is not less than 0.01 and not more than 0.5C; Obtain the charge and discharge capacities corresponding to each number of cycles of each candidate battery material after a preset number of cycles of charge and discharge within a target power range; the value range of the preset number of cycles is not less than 10 times and not more than 50 times.

[0013] In the technical solution of the embodiment of the present application, by performing cyclic charge and discharge on the candidate battery materials under the first magnification condition, the value range of the number of cycles is not less than 10 times and not more than 50 times. Selecting a smaller charge and discharge magnification can obtain a more obvious cumulative preset side reaction charge under a shorter number of cycles, shortening the data acquisition time and helping to accelerate the screening speed of battery materials.

[0014] In some embodiments, obtaining the charge and discharge amounts corresponding to each cycle number after the charge and discharge of multiple candidate battery materials within the target charge range for a preset number of cycles includes: Performing charge and discharge on each candidate battery material respectively at the second magnification; the value range of the second magnification is greater than 0.5C and less than 3C; Obtaining the charge and discharge amounts corresponding to each cycle number after the charge and discharge of each candidate battery material within the target charge range for a preset number of cycles; the value range of the preset number of cycles is greater than 50 times and not more than 300 times.

[0015] In the technical solution of the embodiment of the present application, by performing cyclic charge and discharge on the candidate battery materials under the second magnification condition, the value range of the number of cycles is greater than 50 times and not more than 300 times, so as to obtain the preset side reaction charge of the candidate battery materials.

[0016] In some embodiments, the candidate battery material is an electrolyte; Calculating the preset side reaction charge corresponding to each cycle number according to the charge and discharge amounts corresponding to each cyclic charge and discharge includes: Calculating the positive electrode oxidation charge corresponding to the nth cyclic charge and discharge according to the charge corresponding to the nth cyclic charge and discharge and the discharge amount corresponding to the (n - 1)th cyclic charge and discharge, where n is an integer and 1 < n ≤ the maximum number of cyclic charge and discharges; Determining the positive electrode oxidation charge corresponding to the nth cyclic charge and discharge as the preset side reaction charge corresponding to the nth cyclic charge and discharge.

[0017] Since the consumption of the electrolyte is related to the positive electrode oxidation reaction and the negative electrode reduction reaction, therefore, when predicting the preset side reaction charge, the embodiment of the present application can calculate the preset side reaction charge corresponding to each cycle number through the positive electrode oxidation charge and the negative electrode reduction charge, and thus can obtain the electrolyte consumption situation of batteries in different aging states for prediction.

[0018] In some embodiments, the method for screening battery materials further includes: Based on the preset side reaction cumulative point charges corresponding to each candidate battery material at each cycle number, determining the cycle number - preset side reaction cumulative charge curve corresponding to each candidate battery material.

[0019] In the technical solution of the embodiment of the present application, the cycle number-preset side reaction cumulative quantity curve corresponding to each candidate battery material is determined by the preset side reaction cumulative point quantity corresponding to each cycle number of the candidate battery material, so that the preset side reaction cumulative quantity of each candidate battery material under the same preset conditions can be compared and screened to obtain the target battery material that meets the preset requirements, thereby realizing the rapid screening of the target battery material.

[0020] In some embodiments, based on the preset side reaction accumulated power corresponding to each candidate battery material under the same preset conditions, determining to use the candidate battery material corresponding to the preset side reaction accumulated power that meets the preset requirements as the target battery material includes: Extract the preset side reaction accumulated electricity corresponding to each candidate battery material under the same preset conditions; Compare the preset side reaction accumulated quantities corresponding to the candidate battery materials; In response to the candidate battery material corresponding to the smallest preset side reaction cumulative electric quantity having the best stability, the candidate battery material corresponding to the smallest preset side reaction cumulative electric quantity is used as the target battery material.

[0021] In the technical solution of the embodiment of the present application, since the candidate battery material corresponding to the minimum preset side reaction cumulative electricity has the best stability, the candidate battery material corresponding to the minimum preset side reaction cumulative electricity is used as the target battery material to obtain a target battery material that better meets the requirements.

[0022] In some embodiments, the same preset condition includes the same time and / or the same number of cycles.

[0023] In the technical solution of the embodiment of the present application, the preset side reaction accumulated electric quantity corresponding to each candidate battery at the same time and / or the same number of cycles is compared to improve the accuracy of the target battery material.

[0024] In a second aspect, the present application provides a battery material screening device, comprising: An acquisition module is used to obtain preset side reaction cumulative power corresponding to each number of cycles of multiple candidate battery materials after charging and discharging for a preset number of cycles within a target power range; the preset side reaction cumulative power is the total power consumed by the internal side reactions of the battery after each number of cycles of charging and discharging; the target power range is a true subset of the power range of the battery's remaining power fully charged and discharged; The screening module is used to determine the candidate battery material corresponding to the preset side reaction cumulative quantity that meets the preset requirements as the target battery material based on the preset side reaction cumulative quantity corresponding to each candidate battery material under the same preset conditions.

[0025] In a third aspect, the present application provides an electronic terminal, which includes a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor is used to execute program data to implement the steps in the above-mentioned method for screening battery materials.

[0026] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps in the above-mentioned method for screening battery materials are implemented.

[0027] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a schematic diagram of the process of the battery material screening method provided in this application; Figure 2 yes Figure 1 A schematic flow chart of a specific embodiment of step S1 in the provided method for screening battery materials; Figure 3 It is a structural schematic diagram of an embodiment of a battery detection device provided by the present application; Figure 4 It is a schematic diagram of the cycle number corresponding to the preset side reaction cumulative charge curve of different electrolytes provided in the present application within the target charge range of [90%, 100%]; Figure 5 It is a schematic diagram of the cycle number corresponding to the preset side reaction cumulative charge curve of different electrolytes provided in the present application within the target charge range of [0%, 100%]; Figure 6 yes Figure 1 A schematic flow chart of a specific embodiment of step S2 in the provided method for screening battery materials; Figure 7It is a schematic diagram of a framework of an embodiment of a battery material screening device provided by the present application; Figure 8 It is a schematic diagram of the framework of an embodiment of an electronic terminal provided by the present application; Fig. 9 It is a schematic diagram of a framework of an embodiment of a computer-readable storage medium provided by the present application. DETAILED DESCRIPTION

[0031] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as special equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0040] As the positive and negative active materials embed or extract ions during the battery's charge and discharge cycles, the materials in the battery will be lost with continuous charge and discharge. For example: electrolyte loss, positive electrode material capacity loss, etc. Material loss will have an adverse effect on the life of the battery. Therefore, the material loss of the battery during the cycle process can be captured to screen the battery.

[0041] The high voltage and oxidation resistance of positive electrode materials and electrolyte materials are important parameters of batteries. Generally speaking, it is time-consuming and labor-intensive to judge and select positive electrode materials / electrolyte materials that can withstand high voltage through a complete battery charge and discharge cycle, which is not conducive to improving the screening speed of battery materials.

[0042] In order to solve the above-mentioned technical problems, the present application performs low-rate battery charge and discharge cycles in a partial power range, collects the accumulated power of preset side reactions during the battery charge and discharge cycle, thereby achieving a rapid evaluation of the stability of the positive electrode material / the high-voltage oxidation resistance of the electrolyte, and greatly shortening the material screening cycle.

[0043] It can be understood that the battery material screening method provided in the embodiments of the present application can be applied to electronic devices, which include electronic terminals and servers; the electronic terminals can specifically be smart phones, tablet computers, computers, personal digital assistants (PDA), etc.; the server can specifically be an application server or a Web server.

[0044] To facilitate understanding of the technical solution provided in the embodiments of the present application, the application scenario of the method for screening battery materials provided in the embodiments of the present application is introduced below by taking an electronic device as an example of the execution subject.

[0045] See also Figure 1 , Figure 1 It is a schematic diagram of the process of the battery material screening method provided in this application.

[0046] The present application provides a method for screening battery materials, and the method for screening battery materials includes the following specific steps.

[0047] S1: Obtain preset side reaction cumulative power corresponding to each number of cycles of charge and discharge for multiple candidate battery materials within a target power range; the preset side reaction cumulative power is the total power consumed by internal side reactions of the battery after each number of cycles of charge and discharge; the target power range is a true subset of the power range of the battery when it is fully charged and discharged.

[0048] S2: Based on the preset side reaction cumulative electric quantity corresponding to each candidate battery material under the same preset conditions, determine the candidate battery material corresponding to the preset side reaction cumulative electric quantity that meets the preset requirements as the target battery material.

[0049] Compared to obtaining the preset side reaction cumulative electricity corresponding to each number of cycles of each candidate battery material within the battery's complete charge and discharge electricity range, in the technical solution of the embodiment of the present application, the preset side reaction cumulative electricity corresponding to each number of cycles of each candidate battery material within the target electricity range is obtained, the target electricity range is smaller than the battery's complete charge and discharge electricity range, the battery does not require deep charge and discharge cycles, and the data collection time is shortened. The preset side reaction cumulative electricity of each candidate battery material under the same preset conditions is compared and screened to obtain the target battery material that meets the preset requirements, thereby realizing rapid screening of the target battery material.

[0050] The candidate battery material may be a positive electrode sheet, a negative electrode sheet, or an electrolyte. In the following embodiments, the electrolyte is taken as an example of a candidate battery material for detailed description.

[0051] See also Figure 2 , Figure 2 yes Figure 1A schematic flow chart of a specific embodiment of step S1 in the provided method for screening battery materials.

[0052] Specifically, the specific implementation method of obtaining the preset side reaction accumulated power corresponding to each number of cycles of multiple candidate battery materials after they are charged and discharged for a preset number of cycles within the target power range in step S1 is as follows.

[0053] S11: Obtaining the charge and discharge capacities corresponding to each preset number of cycles of charge and discharge of multiple candidate battery materials within a target power range.

[0054] See also Figure 3 , Figure 3 It is a structural schematic diagram of an embodiment of a battery detection device provided in the present application.

[0055] In one embodiment, each candidate battery material is cyclically charged and discharged within a target power range by a battery detection device, and the charge and discharge capacities corresponding to each preset number of cycles of each candidate battery material within the target power range are collected.

[0056] In one embodiment, the battery detection device includes a DC power supply, a voltage measurement circuit, a current measurement circuit and a processor, such as Figure 1 As shown. Among them, one end of the processor is connected in parallel with one end of the DC power supply, one end of the voltage measurement circuit and one end of the current measurement circuit, the other end of the processor, the other end of the DC power supply and the other end of the voltage measurement circuit are grounded respectively, the other end of the current measurement circuit is connected in series with the battery to be tested with the candidate battery material through a switch, and the other end of the battery with the candidate battery material is grounded. Among them, the voltage measurement circuit is used to detect the voltage at both ends of the battery to be tested; the DC power supply provides current input to the battery to be tested; the current measurement circuit is used to detect the current passing through the circuit; the processor performs the test process by using the DC power supply, the voltage measurement circuit and the current measurement circuit, and performs data processing and outputs the corresponding parameters to realize the quantitative characterization of the preset side reaction cumulative electricity. Specifically, the battery detection device collects the charge and discharge amounts corresponding to each number of cycles of each candidate battery material after the preset number of cycles of charge and discharge in the target electricity range.

[0057] The preset side reaction cumulative power includes the total battery oxidation power, and the total battery oxidation power refers to the total power consumed by the side reactions occurring inside the battery during the cyclic charge and discharge process.

[0058] In some embodiments, the target power interval is [A, B], and the power interval of the battery fully charged and discharged is [0, 100%]. Among them, it is generally assumed that when the remaining power (State of Charge, SOC) of the battery is 100%, the charging voltage of the battery is cut off. For example, for the NCM system, the charging voltage of 100% SOC is cut off to 4.2V; for the LFP system, the charging voltage is cut off to 3.65V; when the remaining power of the battery is A, the charging operation is performed, and after charging to 100% of the remaining power of the battery, a charging operation is completed; discharge at a certain rate to a fixed capacity value, so that the remaining power of the battery reaches A, a discharge is completed.

[0059] NCM system refers to the cathode material system in lithium-ion batteries, and its main components include three elements: nickel (Ni), cobalt (Co), and manganese (Mn). NCM materials combine the advantages of lithium cobalt oxide, lithium manganese oxide, and lithium nickel oxide, and have the characteristics of low cost, low environmental pollution, high energy density, and high voltage platform. Therefore, they have become an important direction for the development of lithium-ion battery materials.

[0060] ‌LFP battery is a lithium-ion battery whose positive electrode material is lithium iron phosphate (LiFePO4), so it is also called lithium iron phosphate battery. ‌This battery has the advantages of large capacity, long cycle life, good high temperature stability, and high discharge power. It is particularly suitable for application scenarios that require high energy density and long life batteries.

[0061] The target power range is a true subset of the power range of the battery when it is fully charged and discharged, and A is less than the value of B. The value of A is greater than 0 and less than 100%, and the value of B is 100%.

[0062] In some embodiments, the target power A in the target power interval ranges from [80%, 98%].

[0063] In the technical solution of the embodiment of the present application, when the value range of the target power A in the target power interval is [80%, 98%], it helps to speed up the screening rate of battery materials.

[0064] In a specific embodiment, the value range of A may be greater than or equal to 0, and the value range of B may be less than 100%. For example, the target power interval may be [0, 70%], [10%, 80%], [25%, 90%], [50%, 95%], [75%, 95%], etc.

[0065] In a specific embodiment, the value range of A can be greater than 0, and the value range of B can be less than or equal to 100%. For example, the target power range can be [50%, 85%], [60%, 95%], [70%, 100%], [90%, 100%], [95%, 100%], etc.

[0066] Since the higher the value of A is, the shorter the charge and discharge cycle time is, and the stronger the preset side reaction is under the same test time, it helps to improve the accuracy of the preset side reaction cumulative power data while also helping to speed up the screening of battery materials.

[0067] In the technical solution of the embodiment of the present application, the higher the battery power, the higher the battery voltage, and the stronger the battery oxidation side reaction occurring under high voltage conditions in the same time period, thereby improving the accuracy of the preset side reaction cumulative power data and accelerating the screening rate of candidate battery materials.

[0068] In one embodiment, each candidate battery material is charged and discharged at a first rate; the value range of the first rate is not less than 0.01 and not more than 0.5C; the charge and discharge amount corresponding to each number of cycles of each candidate battery material after a preset number of cycles in the target power range is obtained; the value range of the preset number of cycles is not less than 10 times and not more than 50 times. The first rate can be 0.05C, 0.1C, 0.15C, 0.2C, 0.25C, 0.3C, 0.35C, 0.4C, 0.45C, 0.5C, etc., and is set according to actual conditions.

[0069] In the technical solution of the embodiment of the present application, by cyclically charging and discharging the candidate battery materials under a first rate condition, the number of cycles is in the range of not less than 10 times and not more than 50 times. Selecting a smaller charge and discharge rate can obtain a preset side reaction cumulative quantity with a more obvious change under a shorter number of cycles, thereby shortening the data collection time and helping to speed up the screening of battery materials.

[0070] In one embodiment, each candidate battery material is charged and discharged respectively at a second rate; the value range of the second rate is greater than 0.5C and less than 3C; the charge and discharge amount corresponding to each number of cycles of each candidate battery material after a preset number of cycles in the target power range is obtained; the value range of the preset number of cycles is greater than 50 times and not more than 300 times. The second rate can be 0.6C, 0.7C, 0.8C, 0.9C, 1C, 1.2C, 1.3C, 1.4C, 1.5C, 1.6C, 1.7C, 1.8C, 1.9C, 2C, 2.2C, 2.3C, 2.4C, 2.5C, 2.6C, 2.7C, 2.8C, 2.9C, 3C, etc., and is set according to actual conditions.

[0071] In the technical solution of the embodiment of the present application, the candidate battery material is cyclically charged and discharged under the second rate condition, and the number of cycles is in the range of greater than 50 times and not more than 300 times, thereby obtaining the preset side reaction power of the candidate battery material.

[0072] Selecting a smaller charge and discharge rate can obtain a preset side reaction cumulative power with a more obvious change in a shorter number of cycles. If a higher charge and discharge rate is selected, the number of cycles may need to be increased. Under the same number of cycles, the greater the rate at which the battery is charged and discharged, the greater the polarization current inside the battery, and the less accurate the preset side reaction cumulative power of the battery measured. Therefore, the embodiment of the present application uses a smaller rate for charging and discharging a battery with a candidate battery material, and can obtain a relatively accurate preset side reaction cumulative power of the candidate electrode material under fewer cycles. For example, the rate used for cyclic charge and discharge of a battery with a candidate electrode material can be: 0.05C, 0.1C, 0.2C, etc. The number of cycles in the charge and discharge of the battery with the candidate electrode material through each number of cycles is the same as the number of cycles of the battery with the candidate electrode material. For example: the number of cycles can be 15 times, 35 times, 50 times, etc.

[0073] In a specific embodiment, the candidate battery material is an electrolyte, and multiple batteries are labeled EL1, EL2, and EL3. Except for the different electrolytes in the three groups of batteries, other components in the batteries are consistent. Charge and discharge for a preset number of cycles within the target power range of [90%, 100%]. The preset number of cycles is not less than 5 times, and can be specifically 16 times. The battery detection device detects the detection current, detection voltage, and time corresponding to each cycle number. The processor determines the charge and discharge amount corresponding to each cycle number based on the detection current, detection voltage, and time corresponding to each cycle number. The charge amount is Qc n , the discharge amount is Qd n , where n is the number of cycles.

[0074] For example, the positive electrodes of the batteries corresponding to EL1, EL2, and EL3 are all positive electrodes NCM811, the negative electrodes of the batteries are all graphite, and the electrolytes of the batteries include ethylene carbonate (EC), ethyl methyl carbonate (EMC), lithium hexafluorophosphate (LiPF6), vinylene carbonate (VC) and / or propylene sulfite (PS). Specifically, the electrolyte of the EL1 battery includes EC: EMC = 3wt%: 7wt%, 1mol / L LiPF6, 2%wt VC; the electrolyte of the EL2 battery includes EC: EMC = 3wt%: 7wt%, 1mol / L LiPF6, 2%wt VC, 2%wt PS; the electrolyte of the EL3 battery includes EC: EMC = 3wt%: 7wt%, 1mol / L LiPF6.

[0075] Connect the batteries labeled EL1, EL2, and EL3 to the battery detection device respectively, close the switch, and charge and discharge the batteries with the candidate electrode materials at a charge and discharge rate of 0.1C. Specifically, charge at a charge rate of 0.1C under a constant current of 20mA until the battery voltage reaches 4.2V and the remaining capacity of the battery reaches 100%. Discharge at a charge rate of 0.1C under a constant current of 20mA for 1h until the remaining capacity of the battery reaches 90%. The discharge capacity corresponding to the first cycle is Qd1, which is 20mAh. The above steps are repeated 20 times to obtain the charge and discharge capacity corresponding to each number of cycles.

[0076] In order to verify the reliability of the battery material screening method provided in this embodiment, the batteries labeled EL1, EL2, and EL3 are connected to the battery detection device respectively, the switch is closed, and the battery with the candidate electrode material is charged and discharged at a charge and discharge rate of 0.1C, and the preset number of cycles are charged and discharged within the target power interval of [0%, 100%]. The preset number of cycles is consistent with the number of cycles in the above embodiment. The battery detection device detects the detection current, detection voltage, and time consumption corresponding to each cycle number, and the processor determines the charge and discharge amount corresponding to each cycle number according to the detection current, detection voltage, and time consumption corresponding to each cycle number. The charge amount is Qc n , the discharge amount is Qd n , where n is the number of cycles.

[0077] Connect the batteries labeled EL1, EL2, and EL3 to the battery detection device respectively, close the switch, and charge and discharge the batteries with the candidate electrode materials at a charge and discharge rate of 0.1C. Specifically, charge at a charge rate of 0.1C under a constant current of 20mA until the battery voltage reaches 4.2V and the remaining battery capacity reaches 100%. Discharge at a charge rate of 0.1C under a constant current of 20mA for 10h until the remaining battery capacity reaches 0%; or discharge at a charge rate of 0.1C under a constant current of 20mA until the battery voltage reaches 3V, at which point the remaining battery capacity is 0%. Repeat the above steps 15 times to obtain the charge and discharge amounts corresponding to each number of cycles.

[0078] S12: Calculate the preset side reaction power corresponding to each cycle number according to the charge and discharge capacity corresponding to each cycle.

[0079] In one embodiment, according to the charging amount corresponding to the nth charge-discharge cycle and the discharging amount corresponding to the (n - 1)th charge-discharge cycle, the positive electrode oxidation amount corresponding to the nth charge-discharge cycle is calculated, where n is an integer and 1 < n ≤ the maximum number of charge-discharge cycles; the positive electrode oxidation amount corresponding to the nth charge-discharge cycle is determined as the preset side reaction amount corresponding to the nth charge-discharge cycle.

[0080] In a specific embodiment, the following formula is used to calculate the positive electrode oxidation amount corresponding to the nth charge-discharge cycle according to the charging amount corresponding to the nth charge-discharge cycle and the discharging amount corresponding to the (n - 1)th charge-discharge cycle.

[0081] ΔQox n =Qc n -Qd n-1 (Formula 1) In the formula: ΔQox n represents the positive electrode oxidation amount corresponding to the nth charge-discharge cycle; Qc n represents the charging amount corresponding to the nth charge-discharge cycle; Qd n-1 represents the discharging amount corresponding to the (n - 1)th charge-discharge cycle.

[0082] For example, when the discharging amount corresponding to the first charge-discharge cycle of the battery is Qd1, Qd1 content of active lithium ions in the negative electrode of the battery are all embedded in the positive electrode. When the second charge-discharge cycle is carried out, a reaction occurs on the surface of the positive electrode. The delithiation reaction causes all the active lithium in Qd1 in the positive electrode to be removed and migrate to the negative electrode; at the same time, the positive electrode oxidation side reaction will cause an increase in the charging amount, expressed as the oxidation amount ΔQox; at this time, the charging amount corresponding to the second charge-discharge cycle of the battery is Qc2 = Qd1 + ΔQre; therefore, the positive electrode oxidation amount ΔQox2 corresponding to the second charge-discharge cycle of the battery is ΔQox2 = Qc2 - Qd1.

[0083] Since the consumption of the electrolyte is related to the positive electrode oxidation reaction and the negative electrode reduction reaction, therefore, when predicting the preset side reaction amount, the embodiments of the present application can calculate the preset side reaction amount corresponding to each cycle number through the positive electrode oxidation amount and the negative electrode reduction amount, and further can obtain the electrolyte consumption situation of the battery for predicting different aging states.

[0084] S13: Sum up the preset side reaction amounts corresponding to the current cycle number and all the historical cycle numbers before the current cycle number to obtain the preset side reaction cumulative amount corresponding to the current cycle number.

[0085] In one embodiment, the following formula is used to obtain the preset side reaction cumulative amount corresponding to the current cycle number.

[0086] (Formula 2) Where: Qox n Indicates the preset cumulative power of the side reaction corresponding to the current cycle number; ΔQox n It indicates the positive electrode oxidation capacity corresponding to the nth cycle of charge and discharge.

[0087] In the technical solution of the embodiment of the present application, by obtaining the charge and discharge amounts corresponding to each cycle number of the candidate battery within the target power range, the data collection time is shortened, and the data acquisition time of the preset side reaction cumulative power corresponding to each cycle number is accelerated, which helps to speed up the screening of battery materials.

[0088] Through the specific implementation steps in the above embodiments, the batteries EL1, EL2, and EL3 are cycled for a preset number of times, and the preset side reaction power corresponding to each number of cycles is calculated using Formula 1 based on the charge and discharge amounts corresponding to each number of cycles; and the preset side reaction cumulative power corresponding to each number of cycles is calculated using Formula 2 based on the preset side reaction power corresponding to each number of cycles.

[0089] In some embodiments, the method for screening battery materials further includes the following steps.

[0090] Based on the preset side reaction cumulative electricity quantity corresponding to each candidate battery material at each cycle number, a cycle number-preset side reaction cumulative electricity quantity curve corresponding to each candidate battery material is determined.

[0091] In the technical solution of the embodiment of the present application, the cycle number-preset side reaction cumulative quantity curve corresponding to each candidate battery material is determined by the preset side reaction cumulative point quantity corresponding to each cycle number of the candidate battery material, so that the preset side reaction cumulative quantity of each candidate battery material under the same preset conditions can be compared and screened to obtain the target battery material that meets the preset requirements, thereby realizing the rapid screening of the target battery material.

[0092] See also Figure 4 and Figure 5 , Figure 4 It is a schematic diagram of the cycle number corresponding to the preset side reaction cumulative charge curve of different electrolytes provided in the present application within the target charge range of [90%, 100%]; Figure 5 It is a schematic diagram of the cycle number corresponding to the preset side reaction cumulative charge curve for different electrolytes provided in this application within the target charge range of [0%, 100%].

[0093] Specifically, the batteries labeled EL1, EL2, and EL3 are within the target power range of [90%, 100%], and the cycle number-preset side reaction cumulative power curves corresponding to the batteries EL1, EL2, and EL3 are fitted based on the cycle number and the preset side reaction cumulative power curves corresponding to the batteries EL1, EL2, and EL3, respectively, are obtained, such as Figure 4 shown.

[0094] Specifically, the batteries labeled EL1, EL2, and EL3 are within the target power range of [0, 100%], and the cycle number-preset side reaction cumulative power curves corresponding to the batteries EL1, EL2, and EL3 are fitted based on the cycle number and the preset side reaction cumulative power curves corresponding to the batteries EL1, EL2, and EL3, respectively, are obtained, such as Figure 5 shown.

[0095] See also Figure 6 , Figure 6 yes Figure 1 A schematic flow chart of a specific embodiment of step S2 in the provided method for screening battery materials.

[0096] Specifically, in step S2, based on the preset side reaction accumulated electricity corresponding to each candidate battery material under the same preset conditions, determining the candidate battery material corresponding to the preset side reaction accumulated electricity that meets the preset requirements as the target battery material specifically includes the following implementation methods.

[0097] S21: extracting the preset side reaction accumulated electricity corresponding to each candidate battery material under the same preset condition.

[0098] In some embodiments, the same preset condition includes the same time and / or the same number of cycles.

[0099] In the technical solution of the embodiment of the present application, the preset side reaction accumulated electric quantity corresponding to each candidate battery at the same time and / or the same number of cycles is compared to improve the accuracy of the target battery material.

[0100] S22: Compare the preset side reaction accumulated quantities corresponding to the candidate battery materials.

[0101] S23: In response to the candidate battery material corresponding to the smallest preset side reaction cumulative electric quantity having the best stability, the candidate battery material corresponding to the smallest preset side reaction cumulative electric quantity is used as the target battery material.

[0102] In a specific embodiment, as shown in the figure, in the batteries labeled EL1, EL2, and EL3, the preset side reaction cumulative power corresponding to the same number of cycles is sorted from small to large, and is EL1, EL2, and EL3 in sequence. The smaller the preset side reaction cumulative power, the better the antioxidant performance of the battery material. Therefore, the candidate battery material in the battery with the smallest preset side reaction cumulative power under the same number of cycles is selected as the target battery material.

[0103] In the technical solution of the embodiment of the present application, since the candidate battery material corresponding to the minimum preset side reaction cumulative electricity has the best high-voltage stability, the candidate battery material corresponding to the minimum preset side reaction cumulative electricity is used as the target battery material to obtain a target battery material that better meets the requirements.

[0104] By Figure 4 and Figure 5 By comparison, it can be seen that the screening method for battery materials provided in this embodiment greatly shortens the data acquisition time. It only takes 2 hours for the battery material to circulate once within the target power interval of [90%, 100%], and it takes 20 hours for the battery material to circulate once within the target power interval of [0%, 100%], which significantly shortens the time. And within the target power interval of [90%, 100%] and [0%, 100%], the trends of the cycle number-preset side reaction cumulative power curves corresponding to the batteries of EL1, EL2, and EL3 are consistent, further confirming that the screening method for battery materials provided in this embodiment is reliable, efficient, and accurate.

[0105] See also Figure 7 , Figure 7 It is a schematic diagram of the framework of an embodiment of a battery material screening device provided in the present application.

[0106] This embodiment provides a battery material screening device 60 , and the battery material screening device 60 includes an acquisition module 61 and a screening module 62 .

[0107] The acquisition module 61 is used to obtain the preset side reaction cumulative power corresponding to each number of cycles of multiple candidate battery materials after each number of cycles of charge and discharge within the target power range; the preset side reaction cumulative power is the total power consumed by the internal side reactions of the battery after each number of cycles of charge and discharge; the target power range is a true subset of the power range of the battery's remaining power when it is fully charged and discharged.

[0108] The screening module 62 is used to determine the candidate battery material corresponding to the preset side reaction cumulative quantity that meets the preset requirements as the target battery material based on the preset side reaction cumulative quantity corresponding to each candidate battery material under the same preset conditions.

[0109] Compared to obtaining the preset side reaction cumulative electricity corresponding to each number of cycles of each candidate battery material within the battery's complete charge and discharge electricity range, in the technical solution of the embodiment of the present application, the preset side reaction cumulative electricity corresponding to each number of cycles of each candidate battery material within the target electricity range is obtained, and the target electricity range is smaller than the battery's complete charge and discharge electricity range, thereby shortening the data collection time, and comparing and screening the preset side reaction cumulative electricity of each candidate battery material under the same preset conditions to obtain the target battery material that meets the preset requirements, thereby achieving rapid screening of the target battery material.

[0110] See also Figure 8 , Figure 8 80 is a schematic diagram of a framework of an embodiment of an electronic terminal provided in the present application. The electronic terminal 80 includes a memory 81 and a processor 82 coupled to each other, and the processor 82 is used to execute program instructions stored in the memory 81 to implement the steps of any of the above-mentioned battery material screening method embodiments. In a specific implementation scenario, the electronic terminal 80 may include, but is not limited to: a microcomputer, a server, and in addition, the electronic terminal 80 may also include a mobile device such as a laptop computer and a tablet computer, which is not limited here.

[0111] Specifically, the processor 82 is used to control itself and the memory 81 to implement the steps of any of the above-mentioned battery material screening method embodiments. The processor 82 can also be called a CPU (Central Processing Unit). The processor 82 may be an integrated circuit chip with signal processing capabilities. The processor 82 can also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field-programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. In addition, the processor 82 can be implemented by an integrated circuit chip.

[0112] See also Fig. 9 , Fig. 9 The computer-readable storage medium 90 stores program instructions 901 that can be executed by a processor, and the program instructions 901 are used to implement the steps of any of the above-mentioned battery material screening method embodiments.

[0113] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0114] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0115] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0116] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0117] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of each implementation method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0118] The above are only implementation modes of the present invention, and are not intended to limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for screening battery materials, characterized in that: include: Obtaining preset side reaction accumulated power corresponding to each number of cycles of multiple candidate battery materials after they have been charged and discharged for a preset number of cycles within a target power range; The preset side reaction cumulative power is the total power consumed by the internal side reactions of the battery after each cycle of charge and discharge; The target power range is a true subset of the power range of the battery being fully charged and discharged; Based on the preset side reaction accumulated electricity corresponding to each of the candidate battery materials under the same preset conditions, the candidate battery material corresponding to the preset side reaction accumulated electricity that meets the preset requirements is determined as the target battery material.

2. The method for screening battery materials according to claim 1, characterized in that: The target power range is [A, B], the battery fully charged and discharged power range is [0, 100%], the value of A is greater than 0 and less than 100%, and the value of B is 100%.

3. The method for screening battery materials according to claim 2, characterized in that: The value range of the target power A in the target power interval is [80%, 98%].

4. The method for screening battery materials according to any one of claims 1 to 3, characterized in that: The step of obtaining the preset side reaction accumulated power corresponding to each number of cycles of charge and discharge of the plurality of candidate battery materials in the target power range after the preset number of cycles includes: Obtaining the charge and discharge capacities corresponding to each number of cycles of the plurality of candidate battery materials after they have been charged and discharged for the preset number of cycles within the target power range; The preset side reaction quantity corresponding to each cycle number is calculated according to the charge quantity and the discharge quantity corresponding to each cycle charge and discharge; The preset side reaction electric quantities corresponding to the current cycle number and all historical cycle numbers before the current cycle number are added together to obtain the preset side reaction cumulative electric quantity corresponding to the current cycle number.

5. The method for screening battery materials according to claim 4, characterized in that: The obtaining of the charge and discharge capacities corresponding to each number of cycles of the plurality of candidate battery materials after the plurality of candidate battery materials have been charged and discharged for the preset number of cycles within the target power range includes: Using a first rate to charge and discharge each of the candidate battery materials respectively; the value range of the first rate is not less than 0.01 and not more than 0.5C; Obtain the charge and discharge capacities corresponding to the preset number of cycles of each candidate battery material after the candidate battery material has been charged and discharged for the preset number of cycles within the target power range; the value range of the preset number of cycles is not less than 10 times and not more than 50 times.

6. The method for screening battery materials according to claim 4, characterized in that: The obtaining of the charge and discharge capacities corresponding to each number of cycles of the plurality of candidate battery materials after the plurality of candidate battery materials have been charged and discharged for the preset number of cycles within the target power range includes: Using a second rate to charge and discharge each of the candidate battery materials respectively; the second rate has a value range of greater than 0.5C and less than 3C; Obtain the charge and discharge capacities corresponding to the preset number of cycles of charge and discharge for each candidate battery material within the target power range; the preset number of cycles has a value range of greater than 50 times and no more than 300 times.

7. The method for screening battery materials according to claim 4, characterized in that: The candidate battery material is an electrolyte; The calculation of the preset side reaction charge corresponding to each cycle number based on the charge amount and the discharge amount corresponding to each charge and discharge cycle includes: Calculating the positive electrode oxidation charge corresponding to the nth charge and discharge cycle according to the charge amount corresponding to the nth charge and discharge cycle and the discharge amount corresponding to the (n - 1)th charge and discharge cycle, where n is an integer and 1 < n ≤ the maximum number of charge and discharge cycles; Determining the preset side reaction charge corresponding to the nth charge and discharge cycle as the positive electrode oxidation charge corresponding to the nth charge and discharge cycle.

8. The method for screening battery materials according to claim 1, characterized in that: The method for screening the battery material further includes: Based on the preset side reaction cumulative point charges corresponding to each candidate battery material at each cycle number, determining the cycle number - preset side reaction cumulative charge curve corresponding to each candidate battery material.

9. The method for screening the battery material according to claim 1 or 8, wherein The determination of using the candidate battery material corresponding to the preset side reaction cumulative charge meeting the preset requirements as the target battery material based on the preset side reaction cumulative charges corresponding to each candidate battery material under the same preset conditions includes: Extracting the preset side reaction cumulative charges corresponding to each candidate battery material under the same preset conditions; Comparing the preset side reaction cumulative charges corresponding to each candidate battery material; In response to the candidate battery material corresponding to the smallest preset side reaction cumulative charge having the best stability, using the candidate battery material corresponding to the smallest preset side reaction cumulative charge as the target battery material.

10. The method for screening battery materials according to claim 1, characterized in that: The same preset conditions include the same moment and / or the same cycle number.

11. A battery material screening device, characterized in that: It includes: An acquisition module, configured to acquire the preset side reaction cumulative charges corresponding to each cycle number after each of a plurality of candidate battery materials is charged and discharged within a target charge amount range for a preset number of cycles; The preset side reaction cumulative charge is the total charge consumed by internal side reactions after the battery is charged and discharged at each cycle number; The target charge amount range is a proper subset of the charge amount range where the remaining charge of the battery is fully charged and discharged; A screening module, configured to determine, based on the preset side reaction cumulative charges corresponding to each candidate battery material under the same preset conditions, to use the candidate battery material corresponding to the preset side reaction cumulative charge meeting the preset requirements as the target battery material.

12. An electronic terminal, characterized in that: The electronic terminal includes a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor is configured to execute program data to implement the steps in the method for screening the battery material according to any one of claims 1 to 10.

13. A computer-readable storage medium, characterized in that: A computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, the steps in the method for screening the battery material according to any one of claims 1 to 10 are implemented.

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