Charge and Discharge Testing Method, Device, Equipment, Medium and Program Product of Battery

Abstract

The present application relates to a battery charge and discharge test method, apparatus, device, medium, and program product. The method comprises: performing multiple charge and discharge tests on a battery cycle, and stopping the charge and discharge tests when a preset condition is met. Compared with conventional technologies, the embodiments of the present application increase the lithium vacancies available at the battery anode during the battery charge and discharge process by increasing the CB value of the battery, thereby amplifying the lithium consumption phenomenon during the multiple charge and discharge tests on the battery cycle, thereby increasing the speed of the battery charge and discharge test while ensuring the safety of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery testing technology, and in particular to a battery charge and discharge testing method, device, equipment, medium and program product. Background Art

[0002] Lithium-ion batteries (or simply lithium batteries) have been widely used in a variety of electrical products due to their high energy density, long cycle life, and lack of memory effect. However, research on lithium battery materials typically requires extensive charge and discharge testing, which significantly impacts both the research process and the development and design of lithium battery products. Therefore, accelerating charge and discharge testing is a crucial research topic.

[0003] In traditional technologies, the charge and discharge test speed is increased by increasing the charge cut-off voltage of the lithium battery, reducing the discharge cut-off voltage of the lithium battery, reducing the charging current when the battery is in a low state of charge (SOC), and / or using constant voltage charging instead of high-temperature stabilization.

[0004] However, traditional technologies may cause permanent failure of lithium batteries, or even fire or explosion of lithium batteries. Summary of the Invention

[0005] In view of the above problems, the present application provides a battery charge and discharge test method, device, equipment, medium and program product, which can solve the problems of permanent battery failure, or even battery fire or explosion in traditional technologies.

[0006] In a first aspect, the present application provides a battery charge and discharge test method, the method comprising:

[0007] Perform multiple charge and discharge tests on the battery cycle;

[0008] When a preset condition is met, the charge and discharge test is stopped; wherein the preset condition includes: the number of charge and discharge cycles is greater than a cycle number threshold, or the capacity attenuation parameter of the battery is less than a attenuation parameter threshold;

[0009] Among them, the CB value of the battery is greater than 1.07.

[0010] In the technical solution of the embodiment of the present application, multiple charge and discharge tests are performed on the battery cycle, and the charge and discharge tests are stopped when preset conditions are met. Compared with traditional technologies, the embodiment of the present application can increase the lithium vacancies available at the battery anode during the battery charge and discharge process by increasing the CB value of the battery, thereby amplifying the lithium consumption phenomenon during the multiple charge and discharge tests of the battery cycle, thereby increasing the speed of the battery charge and discharge test while ensuring the safety of the battery.

[0011] In some embodiments, the CB value of the battery is in the range of [1.27, 2.27].

[0012] In some embodiments, the method further comprises:

[0013] Determine the design initial coulombic efficiency of the battery according to the design CB value of the battery, and the design CB value is greater than 1.07;

[0014] The battery is prepared according to the designed CB value and the designed first coulombic efficiency of the battery.

[0015] In the technical solution of the embodiment of the present application, the design first coulombic efficiency of the battery is determined based on the design CB value of the battery, and then the battery is manufactured based on the design CB value and the design first coulombic efficiency of the battery. In the embodiment of the present application, by increasing the design CB value of the battery, the lithium vacancies available in the anode of the battery manufactured according to the design CB value during the charge and discharge process can be increased, thereby amplifying the lithium consumption phenomenon during multiple charge and discharge tests of the battery cycle, thereby increasing the speed of the battery charge and discharge test while ensuring the safety of the battery.

[0016] In some embodiments, determining the design first coulombic efficiency of the battery according to the design CB value of the battery includes:

[0017] Determine the coulomb efficiency change based on the design CB value, the preset normal CB value and the preset coefficient;

[0018] The design first coulombic efficiency is determined based on the preset normal first coulombic efficiency and the coulombic efficiency change.

[0019] In some embodiments, the CB value is designed to be in the range of [1.27, 2.27].

[0020] In some embodiments, the charge and discharge test includes:

[0021] Performing constant current charging on the battery until the battery voltage reaches a first preset voltage threshold;

[0022] After the constant current charging is completed, the battery is charged at a constant voltage until the charging current of the battery reaches a preset current threshold;

[0023] After the constant voltage charging is completed, the battery is controlled to perform constant current discharge until the battery voltage reaches a second preset voltage threshold.

[0024] In the technical solution of the embodiment of the present application, the battery is charged with a constant current until the battery voltage reaches a first preset voltage threshold; further, the battery is charged with a constant voltage until the battery charging current reaches a preset current threshold; further, the battery is controlled to discharge with a constant current until the battery voltage reaches a second preset voltage threshold. Compared with conventional technology, the CB value of the battery in the embodiment of the present application is greater than the normal CB value in conventional technology, which can increase the lithium vacancies that the battery anode can provide during the battery charging and discharging process, thereby amplifying the lithium consumption phenomenon during the charge and discharge test, thereby increasing the speed of the battery charge and discharge test.

[0025] In some embodiments, performing constant current charging on a battery until a battery voltage of the battery reaches a first preset voltage threshold includes:

[0026] The battery is charged at a constant current according to a first preset rate until the battery voltage reaches a first preset voltage threshold.

[0027] In some embodiments, constant voltage charging of a battery is performed until a charging current of the battery reaches a preset current threshold, including:

[0028] The battery is charged at a constant voltage using a first preset voltage threshold until the charging current of the battery reaches a preset current threshold.

[0029] In some embodiments, controlling the battery to perform constant current discharge until the battery voltage reaches a second preset voltage threshold includes:

[0030] Controlling the battery to discharge at a constant current according to a first preset rate until the battery voltage reaches a third preset voltage threshold and then standing for a preset time;

[0031] Controlling the battery to discharge at a constant current according to a second preset rate until the battery voltage of the battery reaches a third preset voltage threshold again; wherein the second preset rate is less than the first preset rate;

[0032] After standing for a preset time, the battery is controlled to discharge at a second preset rate constant current until the battery voltage reaches a second preset voltage threshold, wherein the second preset voltage threshold is less than the third preset voltage threshold.

[0033] In some embodiments, the method further comprises:

[0034] Obtain a cycle test result, wherein the cycle test result includes: the number of charge and discharge cycles corresponding to when the capacity decay parameter of the battery is less than a decay parameter threshold, and / or decay information of the capacity decay parameter of the battery.

[0035] In a second aspect, the present application also provides a battery charge and discharge test device, which:

[0036] A first testing module is used to perform multiple charge and discharge tests on the battery cycle;

[0037] A second testing module is configured to stop executing the charge and discharge test when a preset condition is met; wherein the preset condition includes: the number of charge and discharge cycles is greater than a cycle number threshold, or the capacity attenuation parameter of the battery is less than a attenuation parameter threshold;

[0038] Among them, the CB value of the battery is greater than 1.07.

[0039] In a third aspect, the present application further provides a charge and discharge test device, which includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of any one of the methods in the first aspect are implemented.

[0040] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of any one of the methods in the first aspect when the computer program is executed by a processor.

[0041] In a fifth aspect, the present application further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the computer program implements the steps of any one of the methods in the first aspect above.

[0042] 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

[0043] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0044] Figure 1 This is a flow chart of a battery charge and discharge test method according to one embodiment of the present application;

[0045] Figure 2This is a flow chart of a battery charge and discharge test method according to another embodiment of the present application;

[0046] Figure 3 This is a flow chart of a battery charge and discharge test method according to another embodiment of the present application;

[0047] Figure 4 A schematic diagram of a capacity decay curve provided in an embodiment of the present application;

[0048] Figure 5 A schematic diagram of a capacity decay rate curve provided in an embodiment of the present application;

[0049] Figure 6 This is a schematic structural diagram of a battery charge and discharge test device according to one embodiment of the present application;

[0050] Figure 7 This is a schematic diagram of the structure of a charge and discharge test device in one embodiment of the present application. DETAILED DESCRIPTION

[0051] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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 term "include" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0053] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0054] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] Lithium-ion batteries (or simply lithium batteries) have been widely used in a variety of electrical products due to their high energy density, long cycle life, and lack of memory effect. These products include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric vehicles, ships, and spacecraft.

[0056] Typically, research on lithium battery materials requires extensive charge and discharge testing. For example, charge and discharge testing of long-life batteries like lithium iron phosphate typically requires tens of thousands of cycles, potentially taking over a year. This significantly impacts both the research on lithium battery materials and the development and design of lithium battery products. Therefore, accelerating charge and discharge testing is a crucial research topic.

[0057] Traditional techniques increase the speed of charge and discharge tests by increasing the battery's charge cutoff voltage, lowering its discharge cutoff voltage, reducing the charge current at low SOC, and / or using constant voltage charging instead of high-temperature static charging. However, these traditional techniques can lead to permanent battery failure, or even fire or explosion.

[0058] To facilitate understanding, some vocabulary is introduced in the embodiments of this application.

[0059] The batteries involved in the embodiments of the present application can be divided into, but not limited to, button batteries, laminated batteries, soft-pack batteries, hard-shell batteries, cylindrical batteries, etc. according to the battery shape.

[0060] The batteries involved in the embodiments of the present application can be classified according to battery materials and include but are not limited to: ternary batteries, lithium iron phosphate batteries, silicon system batteries, carbon silicon system batteries, lithium sulfur batteries, etc.

[0061] The cathode (or positive electrode) of the battery involved in the embodiments of this application will be oxidized during the charging process, and lithium ions can be released from the layered intercalation material of the cathode, pass through the electrolyte, and be intercalated into the anode. Correspondingly, the anode (or negative electrode) of the battery involved in the embodiments of this application will undergo an oxidation reaction during the discharge process, and lithium ions can be released from the anode, pass through the electrolyte, and be re-intercalated into the cathode.

[0062] The cell balance (CB) value of the battery involved in the embodiments of the present application refers to the ratio of the capacity per unit area of the anode and cathode of the battery, which can also be called the CB value or N / P ratio (Negative / Positive).

[0063] During the first charging process of the battery involved in the embodiment of the present application, the electrode material reacts with the electrolyte at the solid-liquid interface to form a passivation layer covering the surface of the electrode material (this process may also be referred to as a formation process). This passivation layer is an interface layer with the characteristics of a solid electrolyte. It is an electronic insulator but an excellent conductor of lithium ions. Lithium ions can be freely embedded in and out of the passivation layer. Therefore, this passivation film is called a solid electrolyte interface film (Solid Electrolyte Interface, SEI film). The SEI film involved in the embodiment of the present application mainly refers to the film generated by the interface reaction between the negative electrode material graphite and the electrolyte.

[0064] In order to increase the speed of the charge and discharge test, the applicant has found that by increasing the CB value of the battery, the lithium vacancies (or active lithium consumption sites) that can be provided by the battery anode during the charge and discharge process of the battery can be increased, which can increase the SEI film formation lithium consumption during the formation process and the active lithium consumption during the SEI film decomposition and / or repair process during each subsequent charge and discharge cycle, thereby accelerating the battery charge and discharge test process.

[0065] Based on the above considerations, the applicant proposed a battery charge and discharge test method. By increasing the CB value of the battery, the lithium vacancies that can be provided by the battery anode during the battery charge and discharge process can be increased, thereby amplifying the lithium consumption phenomenon during multiple charge and discharge tests of the battery cycle. This can achieve the purpose of accelerating the battery charge and discharge test while ensuring the safety of the battery.

[0066] In one embodiment, Figure 1 FIG. 1 is a flow chart of a battery charge and discharge test method in one embodiment of the present application. In the embodiment of the present application, the method is described by applying it to a charge and discharge test device as an example. Figure 1 As shown, the method of the embodiment of the present application may include the following steps:

[0067] Step S101: Perform multiple charge and discharge tests on the battery cycle.

[0068] The CB value (or charging CB value) of the battery in the embodiment of the present application can be greater than 1.07, where 1.07 can be the normal CB value in conventional technology. It should be understood that the CB value of the battery in the embodiment of the present application is greater than the normal CB value in conventional technology so as to increase the lithium vacancies (or active lithium consumption sites) that can be provided by the battery's anode during the battery's charge and discharge process, thereby increasing the SEI film formation lithium consumption during the formation process and the active lithium consumption during the SEI film decomposition and / or repair process during each subsequent charge and discharge cycle, thereby facilitating the acceleration of the battery charge and discharge test process.

[0069] It should be noted that the charge and discharge test method in the embodiment of the present application accelerates the charge and discharge test by focusing on amplifying the lithium consumption of SEI film formation during the formation process and the active lithium consumption during the decomposition and / or repair of the SEI film during each subsequent charge and discharge cycle, and does not involve changes in the battery failure and degradation mechanism. Therefore, the embodiment of the present application can significantly shorten the time spent on charge and discharge testing while keeping the mechanism unchanged, which greatly helps the research and development and design of battery materials.

[0070] For example, the CB value of the battery in the embodiment of the present application can be in the range of [1.27, 2.27]. For example, the CB value of the battery can be in the range of [1.67, 2.27]. Of course, the CB value of the battery in the embodiment of the present application can also be other values greater than the normal CB value in traditional technology, and this is not limited in the embodiment of the present application.

[0071] In this step, the charge and discharge test equipment may perform multiple charge and discharge tests on the battery cycle according to a preset charge and discharge cycle test process, wherein the preset charge and discharge cycle test process may include but is not limited to: charging the battery in stages according to a constant current charging mode and a constant voltage charging mode, and then discharging the battery in stages according to a constant current discharge mode, and then cyclically executing the above-mentioned staged charging and staged discharging steps until the preset conditions are met.

[0072] Step S102: When a preset condition is met, stop executing the charge and discharge test.

[0073] In this step, the charge and discharge test equipment stops performing the charge and discharge test on the above-mentioned battery when it detects that the preset conditions are met, wherein the preset conditions may include but are not limited to: the number of charge and discharge cycles of the above-mentioned battery is greater than a preset cycle number threshold (for example, 10,000), or the capacity attenuation parameter of the above-mentioned battery is less than a preset attenuation parameter threshold (for example, 80%).

[0074] The battery capacity fading parameter involved in the embodiments of the present application can also be equivalent to the capacity retention parameter, which is used to indicate the battery's capacity fading information. It should be understood that when the battery's capacity fading parameter is less than the fading parameter threshold, the battery has reached the end of life (EOL) state.

[0075] Compared with traditional technology, the CB value of the above-mentioned battery in the embodiment of the present application is greater than the normal CB value in the traditional technology, which can increase the lithium vacancies that the battery anode can provide during the battery's charge and discharge process, thereby amplifying the lithium consumption phenomenon during the battery cycle performing multiple charge and discharge tests. Therefore, the embodiment of the present application can accelerate the battery charge and discharge test.

[0076] In the above-mentioned battery charge and discharge test method, the battery is subjected to multiple charge and discharge tests in a cycle, and the charge and discharge tests are stopped when a preset condition is met. Compared with conventional technologies, the embodiments of the present application increase the CB value of the battery to increase the lithium vacancies available at the battery anode during the battery charge and discharge process, thereby amplifying the lithium consumption phenomenon during the multiple charge and discharge tests of the battery. This can increase the speed of the battery charge and discharge test while ensuring the safety of the battery.

[0077] In one embodiment, Figure 2 This is a flow chart of a battery charge and discharge test method in another embodiment of the present application. Based on the above embodiment, the relevant contents of the preparation process of the above battery are introduced and explained in the embodiment of the present application. Figure 2 As shown, the method of the embodiment of the present application may include:

[0078] Step S201: Determine the designed initial coulombic efficiency of the battery according to the designed CB value of the battery.

[0079] The first coulombic efficiency of the battery in the embodiment of the present application refers to the ratio of the first discharge capacity to the first charge capacity of the battery.

[0080] In this step, the charge and discharge test equipment can determine the designed first coulombic efficiency of the battery according to the designed CB value of the battery, wherein the designed CB value can be greater than 1.07, so that the CB value of the battery prepared according to the designed CB value is greater than 1.07.

[0081] For example, the design CB value of the battery in the embodiment of the present application can be in the range of [1.27, 2.27], so that the CB value of the battery prepared according to the design CB value can be in the range of [1.27, 2.27]; of course, the design CB value of the battery in the embodiment of the present application can also be other values greater than the normal CB value in the traditional technology, and this is not limited in the embodiment of the present application.

[0082] In this step, the charge and discharge test equipment can determine the design first coulombic efficiency based on the design CB value, preset normal CB value and preset normal first coulombic efficiency of the battery, wherein the preset normal CB value may include but is not limited to the normal CB value in traditional technology, and the preset normal first coulombic efficiency may include but is not limited to the normal first coulombic efficiency in traditional technology.

[0083] Optionally, the charge and discharge test equipment can determine the coulombic efficiency change based on the design CB value, the preset normal CB value and the preset coefficient, and determine the design first coulombic efficiency based on the preset normal first coulombic efficiency and the coulombic efficiency change.

[0084] For example, the charge and discharge test equipment can determine the coulombic efficiency change according to the designed CB value, the preset normal CB value and the preset coefficient using the following formula (1).

[0085] ΔCE=(x-CB0)*C0 Formula (1)

[0086] Wherein, ΔCE represents the change in coulombic efficiency, x represents the designed CB value, CB0 represents the preset normal CB value, and C0 represents the preset coefficient (eg, 0.5).

[0087] Of course, the charge and discharge test equipment can also determine the change in coulombic efficiency by other variations or equivalent formulas of the above formula (1) based on the designed CB value, the preset normal CB value and the preset coefficient, and this is not limited in the embodiments of the present application.

[0088] Furthermore, the charge and discharge test equipment can determine the designed first coulombic efficiency by the following formula (2) based on the preset normal first coulombic efficiency and the coulombic efficiency change.

[0089] CE=CE0-ΔCE Formula (2)

[0090] Wherein, CE represents the designed first coulombic efficiency, and CE0 represents the preset normal first coulombic efficiency (eg, 93%).

[0091] Of course, the charge and discharge test equipment can also determine the designed first coulombic efficiency according to the preset normal first coulombic efficiency and the coulombic efficiency change through other variations or equivalent formulas of the above formula (2), which is not limited in the embodiments of the present application.

[0092] Step S202: preparing a battery according to the designed CB value and the designed first coulombic efficiency of the battery.

[0093] In this step, the charge-discharge test equipment may transmit the design CB value and design first coulombic efficiency of the battery determined in step S201 above to the battery preparation equipment, so that the battery preparation equipment can prepare the battery according to the received design CB value and design first coulombic efficiency. For example, the battery preparation equipment may determine the manufacturing parameter information of the positive and negative electrode sheets of the battery according to the design CB value and design first coulombic efficiency of the battery, and prepare the battery according to the battery production process according to the manufacturing parameter information of the positive and negative electrode sheets of the battery.

[0094] Specifically, the specific process of preparing batteries by battery preparation equipment according to the designed CB value and the designed first coulombic efficiency can refer to the battery preparation process in the relevant technology, which is not limited in the embodiments of the present application.

[0095] It should be understood that the designed CB value in this step is greater than the normal CB value in conventional technology, so that the CB value of the battery prepared according to the designed CB value is greater than the normal CB value in conventional technology, so as to increase the lithium vacancies that can be provided by the anode of the prepared battery during the charge and discharge process of the battery, thereby increasing the SEI film formation lithium consumption during the formation process and the active lithium consumption during the SEI film decomposition and / or repair process during each subsequent charge and discharge cycle, thereby facilitating the acceleration of the battery charge and discharge test process.

[0096] In this embodiment, the design first coulombic efficiency of the battery is determined based on the design CB value of the battery, and then the battery is manufactured based on the design CB value and the design first coulombic efficiency of the battery. In the embodiments of the present application, by increasing the design CB value of the battery, the lithium vacancies available in the anode of the battery manufactured according to the design CB value during the charge and discharge process can be increased, thereby amplifying the lithium consumption phenomenon during multiple charge and discharge tests of the battery cycle, thereby increasing the speed of the battery charge and discharge test while ensuring the safety of the battery.

[0097] In one embodiment, Figure 3 FIG. 1 is a flow chart of a battery charge and discharge test method in another embodiment of the present application. Based on the above embodiment, the present application embodiment introduces and explains the relevant contents of the charge and discharge test in the above step S101. Figure 3 As shown, the method of the embodiment of the present application may include:

[0098] Step S301: Perform constant current charging on the battery until the battery voltage reaches a first preset voltage threshold.

[0099] In this step, the charge-discharge test device may perform constant current charging on the battery according to a preset charge-discharge cycle test process until the battery voltage reaches a first preset voltage threshold, wherein the first preset voltage threshold may be an upper threshold of the battery charging voltage. Exemplarily, the first preset voltage threshold may include, but is not limited to, 3.65V.

[0100] Optionally, the charge and discharge test device can charge the battery at a constant current according to a first preset rate until the battery voltage reaches a first preset voltage threshold. For example, the first preset rate in the embodiment of the present application can include but is not limited to a 1Cn rate.

[0101] In the embodiments of this application, Cn may refer to the battery capacity corresponding to when the battery voltage reaches a third preset voltage threshold value after the charge-discharge test device charges and discharges the battery according to a preset charge-discharge process. The determination of Cn by charging and discharging the battery according to the preset charge-discharge process by the charge-discharge test device will be described in subsequent embodiments of this application.

[0102] Step S302: After the constant current charging is completed, the battery is charged at a constant voltage until the charging current of the battery reaches a preset current threshold.

[0103] In this step, after the constant current charging is completed, the charge and discharge test equipment can perform constant voltage charging on the battery according to the preset charge and discharge cycle test process until the charging current of the battery reaches a first preset current threshold. For example, the first preset current threshold in the embodiment of the present application can include but is not limited to 0.05Cn.

[0104] Optionally, the charge and discharge test equipment may use a first preset voltage threshold to perform constant voltage charging on the battery until the charging current of the battery reaches the first preset current threshold.

[0105] For example, the charge and discharge test equipment may perform constant voltage charging on the battery at a voltage corresponding to a first preset voltage threshold until the charging current of the battery decreases to the first preset current threshold.

[0106] Step S303: After the constant voltage charging is completed, the battery is controlled to perform constant current discharge until the battery voltage reaches a second preset voltage threshold.

[0107] In this step, after the constant current charging is completed, the charge and discharge test equipment can be left to stand for a preset time, and then perform a staged constant current discharge on the battery until the battery voltage reaches a second preset voltage threshold, where the second preset voltage threshold can be the lower limit of the battery's discharge voltage. For example, the preset time period can include, but is not limited to, 5 minutes, and the second preset voltage threshold can include, but is not limited to, 2.0V.

[0108] Optionally, the charge and discharge test equipment can control the battery to discharge at a constant current at a first preset rate until the battery voltage reaches a third preset voltage threshold and is left to stand for a preset time, wherein the second preset voltage threshold may be less than the third preset voltage threshold. Exemplarily, the third preset voltage threshold may include, but is not limited to, 2.5V. It should be noted that after the battery has been left to stand for the preset time, the battery voltage will again be greater than the third preset voltage threshold.

[0109] Furthermore, the charge-discharge test equipment can control the battery to discharge at a constant current at a second preset rate until the battery voltage reaches a third preset voltage threshold again; wherein the second preset rate can be less than the first preset rate. For example, in the embodiment of the present application, the second preset rate can include, but is not limited to, a 0.04Cn rate.

[0110] It should be understood that when the battery voltage of the battery reaches the third preset voltage threshold again, the charge and discharge testing equipment can also record the number of charge and discharge cycles and the current capacity of the battery, and then determine the current capacity decay parameter of the battery based on the current capacity of the battery, so as to judge whether the preset conditions are met based on the number of charge and discharge cycles and the capacity decay parameter.

[0111] Optionally, the charge and discharge test equipment can determine the current capacity attenuation parameter of the battery according to the current capacity and Cn rate of the battery.

[0112] For example, the charge and discharge test equipment can determine the current capacity attenuation parameter of the battery according to the current capacity and Cn rate of the battery using the following formula (3).

[0113] F=C1 / Cn*100% Formula (3)

[0114] Among them, F represents the current capacity attenuation parameter of the battery, and C1 represents the current capacity of the battery.

[0115] Of course, the charge and discharge test equipment can also determine the current capacity attenuation parameter of the battery according to the current capacity and Cn rate of the battery through other variations of the above formula (3) or equivalent formulas, which is not limited in the embodiments of the present application.

[0116] Furthermore, after standing still for a preset period of time, the charge and discharge test equipment can control the battery to discharge at a second preset rate and constant current until the battery voltage of the battery reaches a second preset voltage threshold.

[0117] Of course, the charge and discharge test equipment can also perform phased constant current discharge on the battery in other ways, which is not limited in the embodiments of the present application.

[0118] It should be noted that the charge and discharge test in the embodiment of the present application can be performed at a preset temperature (for example, 45 degrees), and correspondingly, the data sampling interval can be a preset sampling interval (for example, 30s).

[0119] In the embodiment of the present application, the battery is charged at a constant current until the battery voltage reaches a first preset voltage threshold; further, the battery is charged at a constant voltage until the battery charging current reaches a preset current threshold; and further, the battery is controlled to discharge at a constant current until the battery voltage reaches a second preset voltage threshold. Compared to conventional technology, the CB value of the battery in the embodiment of the present application is greater than the normal CB value in conventional technology, which can increase the lithium vacancies that the battery anode can provide during the battery's charge and discharge process, thereby amplifying the lithium consumption phenomenon during the charge and discharge test, thereby increasing the speed of the battery charge and discharge test.

[0120] The following embodiments of this application introduce the relevant content of determining the above-mentioned Cn by charging and discharging the battery according to the preset charging and discharging process by the charging and discharging device.

[0121] The preset charge and discharge process involved in the embodiments of the present application may include but is not limited to: charging the battery in stages according to a constant current charging mode and a constant voltage charging mode, and then discharging the battery in stages according to a constant current discharging mode.

[0122] For example, in an embodiment of the present application, the charge and discharge test equipment may charge the battery at a constant current according to a third preset rate until the battery voltage reaches a first preset voltage threshold, and then charge the battery at a constant voltage at a voltage corresponding to the first preset voltage threshold until the charging current of the battery decreases to a second preset current threshold. For example, the third preset rate may include, but is not limited to, 0.33C, and the second preset current threshold may include, but is not limited to, 0.05C.

[0123] Furthermore, after standing still for a preset time period, the charge and discharge testing equipment may discharge the battery at a constant current according to a third preset rate until the battery voltage reaches a third preset voltage threshold.

[0124] Furthermore, after the battery is left to stand for a preset period of time, the charge-discharge tester may discharge the battery at a constant current rate according to a fourth preset rate until the battery voltage reaches the third preset voltage threshold again, and record the battery capacity. For example, the fourth preset rate may include, but is not limited to, 0.04C.

[0125] It should be noted that the charge and discharge test equipment may use the battery capacity corresponding to the time when the battery voltage reaches the third preset voltage threshold again after constant current discharge of the battery according to the fourth preset rate as Cn.

[0126] Furthermore, based on the above embodiment, the charge and discharge test equipment can also obtain cycle test results. For example, the cycle test results in the embodiment of the present application may include but are not limited to: the number of charge and discharge cycles corresponding to when the battery's capacity decay parameter is less than the decay parameter threshold, and / or the decay information of the battery's capacity decay parameter, wherein the decay information of the battery's capacity decay parameter is used to indicate the battery's capacity decay change information.

[0127] Figure 4 This is a schematic diagram of the capacity decay curve provided in the embodiment of the present application. Figure 5 The capacity fading rate curve diagram provided in the embodiment of the present application is as follows: Figure 4 and Figure 5As shown, the designed CB value x4 is greater than the designed CB value x3, the designed CB value x3 is greater than the designed CB value x2, the designed CB value x2 is greater than the designed CB value x1, and the designed CB value x1 is greater than the preset normal CB value CB0. As the designed CB value increases, the anode of the prepared battery can provide more lithium vacancies during the charge and discharge process of the battery, thereby increasing the lithium consumption phenomenon during the battery charge and discharge cycle test, thereby accelerating the battery charge and discharge cycle test.

[0128] For ease of understanding, the preset normal CB value CB0 and the designed CB value x4 are compared as an example. Figure 4 and Figure 5 As shown, compared with the battery prepared based on the preset normal CB value CB0, 1) during the initial attenuation of the battery capacity (for example, the number of charge and discharge cycles is 1 to the number of charge and discharge cycles is 50), the capacity attenuation rate of the battery prepared based on the design CB value of x4 increased by about 0.015%; 2) during the subsequent attenuation period (for example, the number of charge and discharge cycles is 50 to the number of charge and discharge cycles is 300), the capacity attenuation rate of the battery prepared based on the design CB value of x4 increased by about 0.010%; 3) during the period when the battery capacity is close to the EOL state (for example, the number of charge and discharge cycles is 300 to the number of charge and discharge cycles is 600), the battery capacity attenuation rates of the two tend to remain consistent (which can indicate that there is no change in the battery failure decay mechanism), and the number of charge and discharge cycles required for the battery prepared based on the design CB value of x4 to reach the EOL state is reduced by about 150 times, and the charge and discharge test time is correspondingly saved by about 20%.

[0129] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0130] Based on the same inventive concept, embodiments of the present application also provide a charge-discharge testing device for implementing the aforementioned battery charge-discharge testing method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of the one or more battery charge-discharge testing device embodiments provided below can be found in the limitations of the battery charge-discharge testing method described above and will not be further elaborated here.

[0131] In one embodiment, Figure 6 This is a schematic diagram of the structure of a battery charge and discharge test device in one embodiment of the present application. The battery charge and discharge test device provided in the embodiment of the present application can be applied to charge and discharge test equipment. Figure 6 As shown, the battery charge and discharge testing device according to the embodiment of the present application may include: a first testing module 601 and a second testing module 602 .

[0132] The first test module 601 is configured to perform multiple charge and discharge tests on the battery cycle;

[0133] The second test module 602 is configured to stop the charge and discharge test when a preset condition is met. The preset condition includes: the number of charge and discharge cycles is greater than a cycle number threshold, or the capacity decay parameter of the battery is less than a decay parameter threshold.

[0134] Among them, the CB value of the battery is greater than 1.07.

[0135] In one embodiment, the CB value of the battery is in the range of [1.27, 2.27].

[0136] In one embodiment, the battery charge and discharge testing device further includes:

[0137] A determination module is used to determine the design first coulombic efficiency of the battery according to the design CB value of the battery, and the design CB value is greater than 1.07;

[0138] The preparation module is used to prepare batteries according to the designed CB value and the designed first coulombic efficiency of the battery.

[0139] In one embodiment, the determination module is specifically configured to:

[0140] Determine the coulomb efficiency change based on the design CB value, the preset normal CB value and the preset coefficient;

[0141] The design first coulombic efficiency is determined based on the preset normal first coulombic efficiency and the coulombic efficiency change.

[0142] In one embodiment, the CB value is designed to be in the range of [1.27, 2.27].

[0143] In one embodiment, the first testing module 601 includes:

[0144] a first charging unit, configured to perform constant current charging on the battery until the battery voltage reaches a first preset voltage threshold;

[0145] The second charging unit is used to perform constant voltage charging on the battery after the constant current charging is completed until the charging current of the battery reaches a preset current threshold;

[0146] The discharge unit is used to control the battery to perform constant current discharge after the constant voltage charging is completed until the battery voltage of the battery reaches a second preset voltage threshold.

[0147] In one embodiment, the first charging unit is specifically configured to:

[0148] The battery is charged at a constant current according to a first preset rate until the battery voltage reaches a first preset voltage threshold.

[0149] In one embodiment, the second charging unit is specifically configured to:

[0150] The battery is charged at a constant voltage using a first preset voltage threshold until the charging current of the battery reaches a preset current threshold.

[0151] In one embodiment, the discharge unit is specifically configured to:

[0152] Controlling the battery to discharge at a constant current according to a first preset rate until the battery voltage reaches a third preset voltage threshold and then standing for a preset time;

[0153] Controlling the battery to discharge at a constant current according to a second preset rate until the battery voltage of the battery reaches a third preset voltage threshold again; wherein the second preset rate is less than the first preset rate;

[0154] After standing for a preset time, the battery is controlled to discharge at a second preset rate constant current until the battery voltage reaches a second preset voltage threshold, wherein the second preset voltage threshold is less than the third preset voltage threshold.

[0155] In one embodiment, the battery charge and discharge testing device further includes:

[0156] The acquisition module is used to obtain the cycle test results, wherein the cycle test results include: the number of charge and discharge cycles corresponding to when the capacity decay parameter of the battery is less than the decay parameter threshold, and / or the decay information of the capacity decay parameter of the battery.

[0157] The battery charge and discharge test device provided in the embodiment of the present application can be used to execute the technical solution in the above-mentioned battery charge and discharge test method embodiment of the present application. Its implementation principle and technical effect are similar and will not be repeated here.

[0158] Each module in the battery charge and discharge test device described above can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in the charge and discharge test device in hardware form, or can be stored in a memory in the charge and discharge test device in software form, so that the processor can call and execute the corresponding operations of each module.

[0159] In one embodiment, Figure 7 This is a schematic diagram of the structure of a charge and discharge test device in one embodiment of the present application. Figure 7 As shown, the charge and discharge test equipment provided in the embodiment of the present application may include a processor, a memory and a communication interface connected through a system bus. The processor of the charge and discharge test equipment is used to provide computing and control capabilities. The memory of the charge and discharge test equipment includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the charge and discharge test equipment is used to communicate with external devices in a wired or wireless manner. When the computer program is executed by the processor, the technical solution in the embodiment of the charge and discharge test method of the battery mentioned above is implemented in the present application. Its implementation principle and technical effect are similar and will not be repeated here.

[0160] Exemplarily, the charge and discharge test equipment may further include a display screen and an input device. The display screen may be a liquid crystal display screen or an electronic ink display screen. The input device may be a touch layer covering the display screen, or a button, trackball or touchpad provided on the outer casing of the charge and discharge test equipment, or an external keyboard, touchpad or mouse, etc.

[0161] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the charge and discharge test equipment to which the solution of the present application is applied. The specific charge and discharge test equipment may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0162] In one embodiment, a charge and discharge test device is also provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the technical solution in the embodiment of the charge and discharge test method of the battery described above in the present application is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0163] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the technical solution in the above-mentioned battery charge and discharge test method embodiment of the present application is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0164] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the technical solution in the above-mentioned battery charge and discharge test method embodiment of the present application is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0165] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. For purposes of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The processors involved in the various embodiments provided herein may be general-purpose processors, central processing units (CPUs), graphics processors (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like, without limitation thereto.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery charge and discharge test method, characterized in that: The method comprises: Perform multiple charge and discharge tests on the battery cycle; When a preset condition is met, the charge and discharge test is stopped; wherein the preset condition includes: the number of charge and discharge cycles is greater than a cycle number threshold, or the capacity decay parameter of the battery is less than a decay parameter threshold; wherein the CB value of the battery is greater than 1.07; The CB value of the battery is in the range of [1.27, 2.27]; The method further comprises: Determining a designed first coulombic efficiency of the battery according to a designed CB value of the battery, wherein the designed CB value is greater than 1.07; Prepare the battery according to the designed CB value and the designed first coulombic efficiency of the battery; Determining the design first coulombic efficiency of the battery according to the design CB value of the battery includes: Determining a coulombic efficiency change according to the designed CB value, the preset normal CB value, and the preset coefficient; The designed first coulombic efficiency is determined according to the preset normal first coulombic efficiency and the coulombic efficiency change.

2. The method according to claim 1, characterized in that The designed CB value is in the range of [1.27, 2.27].

3. The method according to claim 1 or 2, characterized in that The charge and discharge test includes: Performing constant current charging on the battery until the battery voltage of the battery reaches a first preset voltage threshold; After the constant current charging is completed, the battery is subjected to constant voltage charging until the charging current of the battery reaches a preset current threshold; After the constant voltage charging is completed, the battery is controlled to perform constant current discharge until the battery voltage of the battery reaches a second preset voltage threshold.

4. The method according to claim 3, characterized in that The constant current charging of the battery until the battery voltage of the battery reaches a first preset voltage threshold includes: The battery is charged at a constant current according to a first preset rate until the battery voltage of the battery reaches the first preset voltage threshold.

5. The method according to claim 3, characterized in that The constant voltage charging of the battery until the charging current of the battery reaches a preset current threshold comprises: The battery is charged at a constant voltage using the first preset voltage threshold until the charging current of the battery reaches the preset current threshold.

6. The method according to claim 3, characterized in that The controlling the battery to perform constant current discharge until the battery voltage of the battery reaches a second preset voltage threshold includes: Controlling the battery to discharge at a constant current according to a first preset rate until the battery voltage of the battery reaches a third preset voltage threshold and then standing for a preset time; Controlling the battery to discharge at a constant current according to a second preset rate until the battery voltage of the battery reaches the third preset voltage threshold again; wherein the second preset rate is less than the first preset rate; After standing for the preset time, the battery is controlled to discharge at a constant current according to the second preset rate until the battery voltage of the battery reaches the second preset voltage threshold, wherein the second preset voltage threshold is less than the third preset voltage threshold.

7. The method according to claim 1 or 2, characterized in that The method further comprises: Obtaining a cycle test result, wherein the cycle test result includes: the number of charge and discharge cycles corresponding to when the capacity decay parameter of the battery is less than the decay parameter threshold, and / or decay information of the capacity decay parameter of the battery.

8. A battery charge and discharge test device, characterized in that: The device comprises: A first testing module is used to perform multiple charge and discharge tests on the battery cycle; a second testing module, configured to stop executing the charge-discharge test when a preset condition is met; wherein the preset condition includes: the number of charge-discharge cycles is greater than a cycle number threshold, or the capacity decay parameter of the battery is less than a decay parameter threshold; wherein the CB value of the battery is greater than 1.07; The CB value of the battery is in the range of [1.27, 2.27]; The device also includes a preparation module for determining a design first coulombic efficiency of the battery according to a design CB value of the battery, wherein the design CB value is greater than 1.07; and preparing the battery according to the design CB value of the battery and the design first coulombic efficiency; Determining the design first coulombic efficiency of the battery according to the design CB value of the battery includes: Determining a coulombic efficiency change according to the designed CB value, the preset normal CB value, and the preset coefficient; The designed first coulombic efficiency is determined according to the preset normal first coulombic efficiency and the coulombic efficiency change.

9. A charge and discharge test device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

11. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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