Battery test method, device, equipment and test system

Abstract

The invention provides a battery testing method, device and equipment and a testing system. The performance loss condition of a battery can be obtained through short-term testing. The test method comprises the following steps: acquiring cycle parameters of a battery, wherein the cycle parameters comprise performance parameters of the battery corresponding to execution of a predetermined number of cycle operations; and determining the performance loss of the battery in a single cycle operation according to the cycle parameters. The performance loss rate of the battery is obtained by utilizing the performance parameter change caused by executing the cycle operation in a short time, so that the test efficiency can be improved, and the test time and test resources are saved.

Description

Technical Field

[0001] This application relates to the field of batteries, and particularly to a method, device, equipment, and test system for testing batteries. Background Art

[0002] As an energy storage device, batteries have been widely used in many fields such as electronic products, electric vehicles, and energy storage power stations. During the use of batteries, processes such as storage and charge-discharge cycling may all cause performance loss of the batteries, affecting the service life of the batteries. Therefore, how to test the performance loss of batteries has become a problem to be solved. Summary of the Invention

[0003] Embodiments of this application provide a method, device, equipment, and test system for testing batteries, which can obtain the performance loss of batteries through short-term testing.

[0004] In a first aspect, a method for testing a battery is provided. The testing method includes: obtaining cycle parameters of the battery, where the cycle parameters include performance parameters of the battery corresponding to performing a predetermined number of cycle operations; and determining the performance loss of the battery within a single cycle operation according to the cycle parameters.

[0005] The testing method in this application uses the cycle parameters of the battery, that is, the performance parameters when the battery performs a predetermined number of cycle operations, to determine the performance loss of the battery within a single cycle operation. That is to say, by using the change in performance parameters caused by performing cycle operations in a short period, the performance loss rate of the battery is obtained, thereby improving the testing efficiency and saving testing time and testing resources.

[0006] The number of the cycle operations includes, for example, the number of charge-discharge cycles or the number of storage days.

[0007] In some possible implementation manners, the performance parameters include energy, and the performance loss includes energy loss; or, the performance parameters include capacity, and the performance loss includes capacity loss; or, the performance parameters include internal resistance, and the performance loss includes internal resistance loss.

[0008] In a possible implementation manner, the determining the performance loss of the battery within a single cycle operation according to the cycle parameters includes: determining the performance loss of the battery at a standard temperature according to the cycle parameters and a temperature coefficient corresponding to the current test temperature, where the test temperature is greater than the standard temperature.

[0009] Since the attenuation rate of battery performance is related to temperature, and the higher the temperature, the faster the attenuation rate of battery performance. To further shorten the test time, the battery can be made to perform multiple cycle operations at a higher test temperature, and the corresponding performance parameters can be collected during this process. At the same time, in combination with the temperature coefficient matching the current test temperature, the performance loss of the battery at the standard temperature can be determined.

[0010] Optionally, the temperature coefficient is between 1 and 100, or the temperature coefficient is between 1 and 50, or the temperature coefficient is between 1 and 10, or the temperature coefficient is between 1 and 5, or the temperature coefficient is 2.

[0011] Optionally, obtaining the cycle parameters of the battery includes: obtaining the cycle parameters at a predetermined test temperature, where the test temperature is greater than the standard temperature, and the performance loss is the performance loss at the standard temperature.

[0012] The test temperature is greater than the standard temperature. Optionally, the test temperature is between 30°C and 60°C, or the test temperature is between 43°C and 47°C, or the test temperature is between 53°C and 57°C, or the test temperature is 45°C or 55°C. The standard temperature is, for example, room temperature, such as (25 ± 2)°C.

[0013] In a possible implementation, the cycle parameters include the first performance parameter corresponding to the battery performing the first number of cycle operations and the second performance parameter corresponding to the battery performing the second number of cycle operations, where the second number is greater than the first number.

[0014] In a possible implementation, determining the performance loss of the battery within a single cycle operation according to the cycle parameters includes: calculating the performance difference between the first performance parameter and the second performance parameter, and the quantity difference between the second number and the first number; determining the performance loss according to the ratio of the performance difference to the quantity difference.

[0015] In this implementation, the performance loss of the battery within a single cycle operation can be calculated according to C = (Y0 - Y) / (N - N0), where C is the performance loss of the battery within a single cycle operation, N0 is the first number of cycle operations performed by the battery, Y0 is the first performance parameter when the battery performs N0 cycle operations, N is the second number of cycle operations performed by the battery, and Y is the second performance parameter when the battery performs N cycle operations. N0 and N can be two abscissas in the performance decay curve of the battery. Correspondingly, Y0 and Y are the performance parameter values respectively corresponding to the battery at these two abscissas. By using the ratio between the change in performance parameters and the change in the number of cycle operations performed, the performance loss rate of the battery can be represented.

[0016] For example, the first number and the second number are the number of charge-discharge cycles, the first number is 500, and the second number is 1000.

[0017] In a possible implementation, the determining the performance loss according to the ratio between the performance difference and the quantity difference includes: calculating the product of the quantity difference and the temperature coefficient; determining the performance loss as the ratio of the performance difference to the product.

[0018] In this implementation, the number of cycle operations performed by the battery and its corresponding performance parameters can be collected at a relatively high test temperature, and in combination with the temperature coefficient matching the current test temperature, dividing the ratio of the above performance difference to the quantity difference by this temperature coefficient can obtain the performance loss of the battery at the standard temperature.

[0019] In some possible implementations, the cycle parameter further includes a performance evaluation parameter associated with the predetermined quantity. The determining the performance loss of the battery within a single cycle operation according to the cycle parameter includes: calculating the performance difference between the first performance parameter and the second performance parameter; determining the performance loss as the ratio of the performance difference to the performance evaluation parameter.

[0020] By using a pre-set performance evaluation parameter associated with the number of cycle operations performed by the battery, the calculation amount can be reduced and the efficiency of calculating the energy loss within a single cycle operation can be improved.

[0021] For example, the first number is 500, the second number is 1000, and the performance evaluation parameter is 1000.

[0022] Optionally, the performance parameter is the charging energy and the performance loss is the charging energy loss; or, the performance parameter is the discharging energy and the performance loss is the discharging energy loss.

[0023] In a possible implementation, determining the performance loss of the battery within a single cycle operation according to the cycle parameter includes: determining the performance loss according to the cycle parameter, the rated cycle operation number of the battery, and the rated performance parameter of the battery.

[0024] In this implementation, since in some scenarios, the battery performance is often related to its rated cycle operation number, therefore, the performance loss of the battery can also be determined according to the cycle parameter of the battery, in combination with the number of the rated cycle operation and its corresponding rated performance parameter.

[0025] In a possible implementation, determining the performance loss of the battery within a single cycle operation according to the cycle parameter, the rated cycle operation number of the battery, and the rated performance parameter of the battery includes: calculating the performance difference between the first performance parameter corresponding to the battery performing the first number of cycle operations and the rated performance parameter; calculating the first number difference between the second number of the cycle operations performed by the battery and the first number, and the second number difference between the rated cycle operation number and the first number difference, where the second number is greater than the first number; determining the performance loss as the ratio of the performance difference to the second number difference.

[0026] In this implementation, the performance loss of the battery within a single cycle operation can be calculated according to C = (Y0 - Y x ) / [X - (N - N0)], where C is the performance loss of the battery within a single cycle operation, N0 is the first number of the cycle operations performed by the battery, Y0 is the first performance parameter when the battery performs N0 cycle operations, N is the second number of the cycle operations performed by the battery, X is the rated cycle operation number, and Y x is the rated performance parameter. N0 and N can be two abscissas in the performance decay curve of the battery. Correspondingly, Y0 is the performance parameter value corresponding to the battery at the abscissa N0. Calculating (Y0 - Y x ) / [X - (N - N0)] can obtain the parameter C used to characterize the performance loss of the battery.

[0027] For example, the first number and the second number are the number of charge-discharge cycles, the first number is 500, and the second number is 1000.

[0028] In a possible implementation, calculating the first quantity difference between the second quantity and the first quantity, and the second quantity difference between the rated cyclic operation quantity and the first quantity difference includes: calculating the first quantity difference between the second quantity and the first quantity; calculating the product of the first quantity difference and the temperature coefficient; and determining the second quantity difference as the difference between the rated cyclic operation quantity and the product.

[0029] In this implementation, the number of cyclic operations performed by the battery and its corresponding performance parameters can be collected at a relatively high test temperature. Combining with the temperature coefficient matching the current test temperature, after multiplying the above first quantity difference by the temperature coefficient, the second quantity difference between it and the rated cyclic operation quantity is calculated. Then, based on the above performance difference and the second quantity difference, the performance loss of the battery at the standard temperature can be obtained.

[0030] In some possible implementations, the cyclic parameter further includes a performance evaluation parameter associated with the predetermined quantity. Determining the performance loss of the battery within a single cyclic operation according to the cyclic parameter includes: calculating the performance difference between the first performance parameter corresponding to the battery performing the first quantity of cyclic operations and the rated performance parameter; calculating the quantity difference between the rated cyclic operation quantity and the performance evaluation parameter; and determining the performance loss as the ratio of the performance difference to the quantity difference.

[0031] Using the pre-set performance evaluation parameter associated with the number of cyclic operations performed by the battery can reduce the amount of calculation and improve the efficiency of calculating the energy loss within a single cyclic operation.

[0032] For example, the first quantity is 500 and the performance evaluation parameter is 1000.

[0033] Optionally, the performance parameter is the charging energy and the performance loss is the charging energy loss; or the performance parameter is the discharging energy and the performance loss is the discharging energy loss.

[0034] In a possible implementation, the number of cyclic operations is the number of charge-discharge cycles. Wherein, each charge-discharge cycle sequentially includes the following processes: charging the battery to the charging cut-off voltage at a first constant power, standing for a predetermined duration, discharging the battery to the discharging cut-off voltage at a second constant power, and standing for a preset duration.

[0035] Second aspect, a test device for a battery is provided. The test device includes: an acquisition module configured to obtain cycle parameters of the battery, where the cycle parameters include performance parameters of the battery corresponding to performing a predetermined number of cycle operations; and a processing module configured to determine a performance loss of the battery within a single cycle operation according to the cycle parameters.

[0036] In a possible implementation, the number of the cycle operations includes the number of charge-discharge cycles or the number of storage days.

[0037] In a possible implementation, the performance parameters include energy, and the performance loss includes energy loss; alternatively, the performance parameters include capacity, and the performance loss includes capacity loss; alternatively, the performance parameters include internal resistance, and the performance loss includes internal resistance loss.

[0038] In a possible implementation, the processing module is specifically configured to: determine the performance loss of the battery at a standard temperature according to the cycle parameters and a temperature coefficient corresponding to a current test temperature, where the test temperature is greater than the standard temperature.

[0039] In a possible implementation, the temperature coefficient is between 1 and 100, or the temperature coefficient is between 1 and 50, or the temperature coefficient is between 1 and 10, or the temperature coefficient is between 1 and 5, or the temperature coefficient is 2.

[0040] In a possible implementation, the acquisition module is specifically configured to obtain the cycle parameters at a predetermined test temperature, where the test temperature is greater than the standard temperature, and the performance loss is the performance loss at the standard temperature.

[0041] In a possible implementation, the test temperature is between 30°C and 60°C, or the test temperature is between 43°C and 47°C, or the test temperature is between 53°C and 57°C, or the test temperature is 45°C or 55°C.

[0042] In a possible implementation, the cycle parameters include first performance parameters of the battery corresponding to performing a first number of cycle operations and second performance parameters of the battery corresponding to performing a second number of cycle operations, where the second number is greater than the first number.

[0043] In a possible implementation, the processing module is specifically configured to: calculate a performance difference between the first performance parameter and the second performance parameter and a quantity difference between the second number and the first number; and determine the performance loss according to a ratio of the performance difference to the quantity difference.

[0044] In a possible implementation, the processing module is specifically configured to: calculate the product of the quantity difference and the temperature coefficient; determine that the performance loss is the ratio of the performance difference to the product.

[0045] In a possible implementation, the first quantity and the second quantity are the number of charge-discharge cycles, the first quantity is 500, and the second quantity is 1000.

[0046] In a possible implementation, the cycle parameter further includes a performance evaluation parameter associated with the predetermined quantity, and the processing module is specifically configured to: calculate the performance difference between the first performance parameter and the second performance parameter; determine that the performance loss is the ratio between the performance difference and the performance evaluation parameter.

[0047] In a possible implementation, the first quantity is 500, the second quantity is 1000, and the performance evaluation parameter is 1000.

[0048] In a possible implementation, the performance parameter is the charging energy, and the performance loss is the charging energy loss.

[0049] In a possible implementation, the performance parameter is the discharging energy, and the performance loss is the discharging energy loss.

[0050] In a possible implementation, the processing module is specifically configured to: determine the performance loss according to the cycle parameter, the rated cycle operation quantity of the battery, and the rated performance parameter of the battery.

[0051] In a possible implementation, the processing module is specifically configured to: calculate the performance difference between the first performance parameter corresponding to the battery performing the first quantity of cycle operations and the rated performance parameter; calculate the first quantity difference between the second quantity of the cycle operations performed by the battery and the first quantity, and the second quantity difference between the rated cycle operation quantity and the first quantity difference, where the second quantity is greater than the first quantity; determine that the performance loss is the ratio of the performance difference to the second quantity difference.

[0052] In a possible implementation, the processing module is specifically configured to calculate the first quantity difference between the second quantity and the first quantity; calculate the product of the first quantity difference and the temperature coefficient; determine that the second quantity difference is the difference between the rated cycle operation quantity and the product.

[0053] In a possible implementation, the first quantity and the second quantity are the number of charge-discharge cycles, the first quantity is 500, and the second quantity is 1000.

[0054] In a possible implementation, the cycle parameter further includes a performance evaluation parameter associated with the predetermined quantity, and the processing module is specifically configured to: calculate a performance difference between a first performance parameter corresponding to the battery performing a first quantity of cycle operations and the rated performance parameter; calculate a quantity difference between the rated number of cycle operations and the performance evaluation parameter; and determine the performance loss as a ratio of the performance difference to the quantity difference.

[0055] In a possible implementation, the first quantity is 500 and the performance evaluation parameter is 1000.

[0056] In a possible implementation, the performance parameter is charging energy and the performance loss is charging energy loss.

[0057] In a possible implementation, the performance parameter is discharging energy and the performance loss is discharging energy loss.

[0058] In a possible implementation, the number of cycle operations is the number of charge-discharge cycles, and each charge-discharge cycle sequentially includes the following processes: charging the battery to a charging cut-off voltage at a first constant power, standing for a predetermined duration, discharging the battery to a discharging cut-off voltage at a second constant power, and standing for a predetermined duration.

[0059] In a third aspect, a battery testing device is provided, including a processor and a memory. The memory is used to store instructions, and the processor is used to execute the instructions to implement the testing method described in the first aspect or any possible implementation of the first aspect.

[0060] In a fourth aspect, a battery testing system is provided. The testing system includes: a battery; a charge-discharge device for charging and discharging the battery; and the testing device described in the third aspect or any possible implementation of the third aspect for testing the performance loss of the battery during the charge-discharge process. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the drawings without creative efforts.

[0062] Figure 1 is a schematic flowchart of a battery testing method according to an embodiment of the present application.

[0063] Figure 2 is a schematic diagram of the connection mode of a battery testing circuit.

[0064] Figure 3 It is a schematic diagram of the performance degradation curve of a possible battery.

[0065] Figure 4 It is a schematic flowchart of the battery test method according to another embodiment of the present application.

[0066] Figure 5 It is a schematic diagram of obtaining the temperature coefficient according to the embodiment of the present application.

[0067] Figure 6 It is a schematic diagram of the discharge performance degradation curve of a possible battery.

[0068] Figure 7 It is a schematic block diagram of the battery test device according to the embodiment of the present application.

[0069] Figure 8 It is a schematic block diagram of the battery test equipment according to the embodiment of the present application. Detailed implementation manners

[0070] The following further describes the implementation manners of the present application in detail with reference to the drawings and embodiments. The detailed descriptions and drawings of the following embodiments are used to exemplarily illustrate the principle of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0071] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the description of the present application in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of the present application are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification, claims or drawings of the present application are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0072] Referring to "embodiment" in the present application means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application may be combined with other embodiments.

[0073] In the description of the present application, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", "linked", and "attached" 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 directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0074] The term "and / or" in the present application is merely an association relationship describing associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after.

[0075] In the present application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width, etc. of the integrated device are only for illustrative purposes and should not constitute any limitation to the present application.

[0076] Referring to "embodiment" in the present application means that the specific features, structures, or characteristics described in combination with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments.

[0077] A battery generally refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, in a power system, the battery can include a battery module or a battery pack. Generally, the battery also includes a box for encapsulating one or more battery cells. The box can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells. Again, for example, in an energy storage system, the battery can include an electrical box, a battery cluster, an electrical cabinet, a container, etc. Among them, the electrical box includes a plurality of battery clusters connected in series and / or in parallel, and the electrical cabinet can be regarded as a battery product formed by the battery clusters. A plurality of electrical cabinets are connected in parallel and / or in series to form a container.

[0078] Optionally, the battery can be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-sulfur battery, a lithium-air battery, a sodium-ion battery, a magnesium-ion battery, etc., and the present application does not make any limitation thereto.

[0079] During the use of a battery, processes such as its storage and charge-discharge cycles may all lead to performance losses of the battery, affecting the battery's service life. Such performance losses can, for example, refer to changes in energy, capacity, internal resistance, and open-circuit voltage, etc. For power batteries, their performance losses usually consider capacity loss and internal resistance loss; for energy storage batteries, their performance losses usually consider energy loss. The cycle performance of the battery under specific working conditions can be calculated by testing performance parameters such as energy and capacity at the initial state, i.e., the BOL state, and the end-of-life state, i.e., the EOL state. However, since the battery needs to reach the EOL state, the testing process requires a large amount of resources and time, affecting the testing efficiency.

[0080] To this end, the embodiments of the present application provide a solution for testing the performance of a battery, aiming to determine the average performance loss of the battery within a single cycle operation by using the cycle parameters of the battery, i.e., the performance parameters when the battery performs a certain number of cycle operations, which has a high testing efficiency and saves testing time and testing resources.

[0081] The test object in the embodiments of the present application can be, for example, a battery cell, a battery module, or a battery cluster, etc. Hereinafter, as an example, the battery mentioned refers to a battery cell, i.e., a battery core.

[0082] Figure 1 The schematic flowchart of the test method for the battery in the embodiments of the present application is shown. As Figure 1 shown, the test method 100 includes some or all of the following steps.

[0083] In step 110, the cycle parameters of the battery are obtained.

[0084] Among them, the cycle parameters include the performance parameters of the battery corresponding to the battery performing a predetermined number of cycle operations.

[0085] In step 120, based on the cycle parameters, the performance loss of the battery within a single cycle operation is determined.

[0086] In the embodiments of the present application, by using the changes in performance parameters caused by the battery performing a number of cycle operations in a short period, the performance loss rate of the battery is obtained, without waiting for the battery capacity to decay to the end of life, so the testing efficiency can be improved and testing time and testing resources can be saved.

[0087] It can be understood that the performance loss of the battery within a single cycle operation described in the embodiments of the present application can characterize the performance loss rate of the battery, i.e., the rate or acceleration of the battery performance decay. The decay of the battery performance can also be regarded as the decay of the battery life.

[0088] Moreover, the performance loss described in the embodiments of the present application is the average performance loss of the battery, which is equivalent to the performance loss of the battery in each cycle operation, and is also referred to as the average performance loss or equivalent performance loss within a single cycle operation.

[0089] Optionally, the performance parameter includes energy, and the performance loss includes energy loss; or, the performance parameter includes capacity, and the performance loss includes capacity loss; or, the performance parameter includes internal resistance, and the performance loss includes internal resistance loss.

[0090] The cycle operation may include, for example, a charge-discharge cycle or a predetermined duration such as one day. Correspondingly, the number of cycle operations performed may include the number of charge-discharge cycles or the number of storage days. Herein, one charge and one discharge may be referred to as one charge-discharge cycle, or one round. For example, each charge-discharge cycle sequentially includes the following processes: charging the battery to the charge cut-off voltage at a first constant power, standing for a predetermined duration, discharging the battery to the discharge cut-off voltage at a second constant power, and standing for a predetermined duration.

[0091] In this way, the number of cycle operations performed by the battery can be understood as the number of charge-discharge cycles performed by the battery; or, the number of cycle operations performed by the battery can be understood as the number of storage operations performed by the battery. The storage operation herein refers to an operation for a single storage period. For example, if a single storage period is one day, the number of storage operations performed is the number of storage days. Of course, in the embodiments of the present application, the number of cycle operations performed by the battery can also be referred to as the number of cycle units experienced by the battery. The cycle unit may refer to, for example, the above-mentioned single charge-discharge cycle or single storage period. Correspondingly, the number of cycle units experienced may be the number of charge-discharge cycles or the number of storage days.

[0092] The performance parameter of the battery corresponding to the number of cycle operations performed may, for example, refer to the performance parameter of the battery when the battery performs that number of cycle operations, or the performance parameter of the battery when the battery performs that number of cycle operations. For example, the performance parameter of the battery when it undergoes N charge-discharge cycles, or the performance parameter of the battery when it is stored for M days.

[0093] Optionally, the predetermined number described in step 110 may be less than the rated number of cycle operations of the battery. For example, when the cycle operation is a charge-discharge cycle of the battery, the predetermined number may be less than or equal to 1000; further, the predetermined number is less than or equal to 800; further, the predetermined number is less than or equal to 500.

[0094] The performance parameters included in the cycle parameters may be one or more. For example, the cycle parameters may include the first performance parameter corresponding to the battery performing the first number of cycle operations; for another example, the cycle parameters may include the first performance parameter corresponding to the battery performing the first number of cycle operations and the second performance parameter corresponding to the battery performing the second number of cycle operations. Of course, in addition to the first performance parameter and the second performance parameter obtained through actual tests, the cycle parameters may also include other parameters, such as the rated number of cycle operations and the rated performance parameters of the battery, or the performance evaluation parameters related to the number of cycle operations performed on the battery and / or the test temperature, etc.

[0095] Before the test, optionally, the connection of the test circuit of the battery can be completed according to Figure 2 the connection method shown. Specifically, it may include the following steps: a) Select a charge and discharge device according to the voltage and power range of the battery to be tested; b) Select an environmental simulation device according to the test temperature, humidity requirements and the size of the battery; c) Place the battery in the environmental simulation device; d) Connect the positive and negative electrodes of the battery to the charge and discharge device through connecting wires to form a charge and discharge loop; e) Connect the data sampling wire of the charge and discharge device to the sampling points of the voltage and temperature of the battery, and the temperature sampling points should be arranged on the plane with a larger area on the outer surface of the battery.

[0096] Then, optionally, the initial discharge of the battery can be performed based on the rated power of the battery. When performing the initial discharge of the battery, the temperature of the environmental simulation device can be set to (25±2)°C. For example, for a single battery cell, the initial discharge of the single battery cell under the rated power condition can be completed according to the following steps: a) Stand still at room temperature, for example, (25±2)°C for 5 h; b) Charge at a constant power of Prc until the charge cut-off voltage of the single battery cell, and stand still for a preset duration, for example, 10 min, and record the power, time, voltage, temperature, and charge energy; c) Discharge at a constant power of Prd until the discharge cut-off voltage of the single battery cell, and stand still for a preset duration, for example, 10 min, and record the power, time, voltage, temperature, and discharge energy; d) The initial discharge ends.

[0097] For another example, for a battery module, the initial discharge of the battery module under the rated power condition can be completed according to the following steps: a) Stand still at room temperature, for example, (25±2)°C for 5 h; b) Charge at a constant power of Prc until the charge cut-off voltage of any single cell or module, and stand still for a preset duration, for example, 10 min, and record the power, time, voltage, temperature, and charge energy; c) Discharge at a constant power of Prd until the discharge cut-off voltage of any single cell or module, and stand still for a preset duration, for example, 10 min, and record the power, time, voltage, temperature, and discharge energy; d) The initial discharge ends.

[0098] For another example, for a battery cluster, the initialization discharge of the battery cluster under the rated power condition can be completed according to the following steps: a) Stand still at room temperature, for example, (25 ± 2)°C for 5 h; b) Charge at a constant power of Prc until the charging cut-off voltage of any single cell, any module or the cluster, and stand still for a preset duration, for example, 10 min, and record the power, time, voltage, temperature, and charging energy; c) Discharge at a constant power of Prd until the discharging cut-off voltage of any single cell, any module or the cluster, and stand still for a preset duration, for example, 10 min, and record the power, time, voltage, temperature, and discharging energy; d) The initialization discharge ends.

[0099] Optionally, after the initialization discharge ends, the battery is stood still at room temperature, for example, (25 ± 2)°C for 5 h. Then, charge and discharge cycles are performed on the battery.

[0100] As an example, the following steps can be referred to for performing charge and discharge cycles on the battery: a) At the test temperature, the battery is charged at a constant power of Prc until the charging cut-off voltage of the battery, and performance parameters of the battery such as charging energy, charging time, battery surface temperature, etc. are recorded; b) Stand still for a preset duration, for example, 10 min; c) At the test temperature, the battery is discharged at a constant power of Prd until the discharging cut-off voltage of the battery, and performance parameters of the battery such as discharging energy, discharging time, battery surface temperature, etc. are recorded; d) Stand still for a preset duration, for example, 10 min. It can be understood that steps a) to d) are one charge and discharge cycle, that is, the number of charge and discharge cycles is 1. Continuously execute the above steps a) to d) in a loop, obtain the performance parameters of the battery after performing multiple charge and discharge cycles, and record the number of charge and discharge cycles and their corresponding performance parameters, so as to determine the performance loss within a single charge and discharge cycle of the battery, such as the loss of charging energy or discharging energy.

[0101] In step 120, two methods for calculating the battery performance loss are provided, which are described separately below.

[0102] Method 1

[0103] In some embodiments, the cycle parameters of the battery include the first number N0 of cycle operations performed by the battery, the first performance parameter Y0 of the battery corresponding to the first number N0 of cycle operations, the second number N of cycle operations performed by the battery, and the second performance parameter Y of the battery corresponding to the second number N of cycle operations, where the second number N is greater than the first number N0, that is, N0 < N. At this time, in step 120, calculate the performance difference between the first performance parameter Y0 and the second performance parameter Y, that is, Y0 - Y, and the quantity difference between the second number N and the first number N0, that is, N - N0, and determine the performance loss C of the battery within a single cycle operation according to the ratio between the performance difference Y0 - Y and the quantity difference N - N0.

[0104] Assume that a battery is applied to a certain working condition from its initial state, i.e., the BOL state, and its attenuation curve is, for example, Figure 3 as shown. Here, the abscissa is the number of cycle operations performed by the battery, such as the number of charge-discharge cycles, i.e., the number of turns, or the number of storage days of the battery, and the ordinate is the corresponding performance parameter, such as energy, capacity, etc. Test the value Y0 of the performance parameter of the battery when it decays to N0 cycle operations, and the value Y of the performance parameter of the battery when it continues to decay to N cycle operations. Among them, N can be selected, for example, as a point near the Figure 3 end position of the curve shown, and N0 can be selected, for example, as Figure 3 a relatively smooth point in the middle of the curve shown. The performance parameter value corresponding to N is Y, and the performance parameter value corresponding to N0 is Y0. Through the following formula (1), calculate the performance loss of the battery within a single cycle operation:

[0105] C = (Y0 - Y) / (N - N0) (1);

[0106] where C is the performance loss of the battery within a single cycle operation, Y0 is the performance parameter of the battery when it performs N0 cycle operations, and Y is the performance parameter of the battery when it performs N cycle operations.

[0107] By using the ratio between the change amount of the performance parameter of the battery during this period and the change amount of the number of cycle operations performed, the performance loss rate of the battery can be calculated.

[0108] Calculate the value of C using formula (1). Through the value of C, the attenuation rates of different performance parameters caused by processes such as charge-discharge and storage of the battery can be understood. For different batteries, their performance attenuation rates may be different.

[0109] Method 2

[0110] Since in some scenarios, the battery performance is often related to its rated cycle operation number, therefore, in some embodiments, in step 120, this performance loss can be determined according to the cycle parameter, the rated cycle operation number of the battery, and the rated performance parameter of the battery.

[0111] That is to say, according to the cycle parameter of the battery, and in combination with the number of this rated cycle operation and its corresponding rated performance parameter, determine this performance loss of the battery. For example, the number of this rated cycle operation can be the number of charge-discharge cycles performed at the rated power. Correspondingly, the rated performance parameter can be the discharge performance or the charge performance of the battery when performing this number of charge-discharge cycles.

[0112] In some embodiments, the cycling parameters of the battery include a first number N0 of cycling operations performed by the battery, a first performance parameter Y0 of the battery corresponding to the first number N0 of cycling operations, and a second number N of cycling operations performed by the battery, where the second number N is greater than the first number N0, i.e., N0 < N. At this time, in step 120, calculate a first quantity difference N - N0 between the second number N and the first number N0, and a rated number of cycling operations N x and a second quantity difference N x - (N - N0) between the first quantity difference N - N0, and calculate a performance difference Y0 - Y between the first performance parameter Y0 and the rated performance parameter Y x Finally, determine that the performance loss of the battery in a single cycling operation is the ratio of the performance difference Y0 - Y x to the second quantity difference N x - (N - N0). x

[0113] Assume that the battery is applied to a certain working condition from the initial state, i.e., the BOL state, and its attenuation curve is as shown, for example Figure 3 . Among them, the abscissa is the number of cycling operations performed by the battery, such as the number of charge-discharge cycles, i.e., the number of turns, or the storage days of the battery, and the ordinate is the corresponding performance parameter, such as energy, capacity, etc. Test the parameter value Y0 of the performance parameter of the battery when it decays to N0 cycling operations, and continue to decay to N cycling operations after the performance decays to the performance parameter Y0. The rated number of cycling operations of the battery is N x , and the rated performance parameter when performing N x cycling operations is Y x .

[0114] Among them, N can be selected, for example, as a point near the end position of the curve shown Figure 3 , and N0 can be selected, for example, as a relatively smooth point in the middle of the curve shown Figure 3 . The performance parameter value corresponding to N is Y, and the performance parameter value corresponding to N0 is Y0. Through the following formula (2), calculate the performance loss of the battery in a single cycling operation:

[0115] C = (Y0 - Y x ) / [X - (N - N0)] (2);

[0116] Among them, C is the performance loss of the battery in a single cycling operation, Y0 is the performance parameter of the battery when performing N0 cycling operations, X is the rated number of cycling operations, and Y x is the rated performance parameter.

[0117] ​Calculate the C value using formula (2). Through the C value, the decay rates of different performance parameters caused by processes such as battery charging, discharging, and storage can be understood. For different batteries, their performance decay rates may be different.

[0118] In some embodiments, as Figure 4 shown, step 120 may include step 121.

[0119] In step 121, determine the performance loss of the battery at the standard temperature according to the cycle parameter and the temperature coefficient corresponding to the current test temperature.

[0120] At this time, optionally, in step 110, the cycle parameter may be obtained at a predetermined test temperature. Wherein, the test temperature is greater than the standard temperature, and the performance loss within the single cycle operation described in step 120 is the performance loss at the standard temperature.

[0121] Since the decay rate of battery performance is associated with temperature, and the higher the temperature, the faster the decay rate of battery performance. To further shorten the test time, the usually selected test temperature is greater than the standard temperature. That is, the battery is made to perform multiple cycle operations at a higher test temperature, and during this process, the corresponding performance parameters are collected, and at the same time, combined with the temperature coefficient matching the current test temperature, the performance loss of the battery at the standard temperature is determined. Especially for long-life batteries, when performing performance evaluation, the acquisition of cycle parameters should be based on a higher temperature, otherwise it will take a lot of time to obtain the above-mentioned C value.

[0122] Optionally, the temperature coefficient is between 1 and 100; further, the temperature coefficient is between 1 and 50; further, the temperature coefficient is between 1 and 10; further, the temperature coefficient is between 1 and 5; preferably, the temperature coefficient is 2.

[0123] The test temperature is greater than the standard temperature, and the standard temperature is, for example, room temperature, such as (25 ± 2) °C. Optionally, the test temperature is between 30 °C and 60 °C; further, the test temperature is between 43 °C and 47 °C, that is, (45 ± 2) °C; or, the test temperature is between 53 °C and 57 °C; preferably, the test temperature is (45 ± 2) °C, (50 ± 2) °C or (55 ± 2) °C.

[0124] Select a suitable test temperature, such as T 45 = 45 °C and T 55Test at 55 °C to obtain the decay curve of a certain performance parameter and calculate the performance loss C of the battery at this test temperature through the above formula (1) or formula (2). Then, extrapolate the calculated result based on the corresponding theoretical formula such as Arrhenius to obtain the performance loss C0 of the battery at the standard temperature, such as 25 °C.

[0125] For example, in the embodiment of the present application, it is assumed that the performance decay of the battery conforms to formula (3):

[0126] Q = a * t z (3);

[0127] Wherein, Q is the change in battery performance, t is the number of cyclic operations performed by the battery, such as the number of charge-discharge cycles or the storage time, z is the shape constant of the performance change, and its value range is 0.4 to 1, and a is the acceleration coefficient, which can be represented by the above C.

[0128] According to formula (3), formula (4) can be derived:

[0129]

[0130] Wherein, taking the standard temperature of 25 °C as an example, C0 is the performance loss within each cyclic operation at 25 °C, T 0＝ 25 °C, and k is the Arrhenius activation energy.

[0131] Taking the logarithm of both sides of formula (4) can obtain formula (5):

[0132]

[0133] Substitute T 45 = 45 °C, T 45 = 45 °C, the performance loss a 45 , T 55 = 55 °C, and T 55 = 55 °C, the performance loss a 55 , into formula (5) respectively, and the parameters C0 and k can be determined. The parameter C0 is the performance loss of the battery within a single cyclic operation at T 0＝ 25 °C.

[0134] Furthermore, in order to simplify the entire calculation process, optionally, the present application can form the above temperature coefficient based on certain assumptions, so as to calculate the above C0 through a simpler expression.

[0135] Assume that z = 1 in formula (3), that is, assume that the performance loss of the battery is a linear loss, and the performance loss at a certain temperature T is β times the performance loss at T 0＝ 25 °C. Then formula (3) is simplified to formula (6):

[0136] Q = a * t (6);

[0137] Where Q is the change in battery performance, t is the number of cyclic operations performed by the battery, such as the number of charge-discharge cycles or the storage time, and a is the acceleration coefficient.

[0138] For a fixed temperature T, Equation (4) can be expressed as Equation (7):

[0139] a = C0 * β (7);

[0140] Combining the above calculation method of the performance loss C, the acceleration coefficient a has the same meaning and is equal to the performance loss C. Therefore, Equation (8) can be obtained:

[0141] C = C0 * β (8);

[0142] By transforming Equation (8), Equation (9) is obtained:

[0143]

[0144] For the above Method 1 for calculating the value of C, considering the temperature coefficient β, it is necessary to calculate the product of the difference in the number of the second quantity N and the first quantity N0, i.e., (N - N0), and the temperature coefficient β, and determine that the performance loss C0 at the standard temperature is the ratio of the performance difference between the first performance parameter Y0 and the second performance parameter Y, i.e., (Y0 - Y), to this product.

[0145] That is, according to Equation (1) and Equation (9), it can be obtained:

[0146]

[0147] For the above Method 2 for calculating the value of C, considering the temperature coefficient β, after calculating the first difference N - N0 between the second quantity N and the first quantity N0, calculate the product of this first difference N - N0 and the temperature coefficient β, and then subtract this product from the rated cyclic operation quantity N x to obtain the second difference X - (N - N0), so as to obtain that the performance loss C0 at the standard temperature is the ratio of the performance difference between the first performance parameter Y0 and the rated performance parameter Y x i.e., (Y0 - Y) x , to the second difference N x -(N - N0).

[0148] That is, according to Equation (2) and Equation (9), it can be obtained:

[0149]

[0150] For different test temperatures T, the corresponding temperature coefficient β may be different.

[0151] Through Formula (10) and Formula (11), as well as the cycle parameters of the battery obtained at the test temperature T, combined with the temperature coefficient β, it is possible to calculate the performance loss of the battery during a single cycle operation at a standard temperature, such as 25°C.

[0152] The following describes a possible way to obtain the temperature coefficient β.

[0153] For batteries with different chemical systems and structures, the value of the temperature coefficient β may be different. The temperature coefficient β can be determined by means of a large sample. For example, as Figure 5 shown, 14 lithium iron phosphate chemical system batteries are selected as samples. Their performance decay curves are tested at the same temperature T, and their performance decay curves are also tested at 25°C. Assuming that the performance loss of the battery is a linear loss, using the aforementioned Method 1 or Method 2, based on the performance loss C of the battery at temperature T and the performance loss C0 of the battery at 25°C, the temperature coefficient β corresponding to each battery can be calculated, and the distribution is as Figure 5 shown.

[0154] Taking the average value of the temperature coefficients β of the 14 batteries, β = 2 can be obtained. Therefore, for lithium iron phosphate batteries, β = 2 can be used as the conversion coefficient from temperature T to 25°C.

[0155] As an example, as Figure 6 shown in the performance decay curve of the battery, the abscissa is the number of cycles, that is, the number of charge and discharge cycles, and the ordinate is the discharge energy. During the process of cyclic charge and discharge of the battery, the energy during the charging stage can be recorded to form a charging performance decay curve, or the energy during the discharging stage can be recorded to form a discharging performance decay curve. Figure 6 Taking the discharge energy decay as an example. As Figure 6 shown, N is a point near the end of the curve, and N0 is a relatively smooth point in the middle of the curve. It can be seen that from N0 onwards, the performance decay is basically a linear decay. N0 = 500, N = 1000, the performance parameter value corresponding to N is Y = 0.948, and the performance parameter value corresponding to N0 is Y0 = 0.910. Assuming that the rated number of cycles Y x of the battery = 12000 cycles, and the rated discharge energy X = 500 Wh. Figure 6 The performance decay curve shown is the discharging performance decay curve of the battery at the test temperature of 45°C, and the temperature coefficient β corresponding to 45°C is β = 2.

[0156] In order to reduce the computational amount and improve the efficiency of calculating the energy loss within a single cycle operation, in some other embodiments, a preset performance evaluation parameter associated with the number of cycle operations performed by the battery may be introduced. For example, in addition to including a first performance parameter corresponding to the battery performing a first number of cycle operations and a second performance parameter corresponding to the battery performing a second number of cycle operations, the cycle parameter may further include the performance evaluation parameter associated with the first number and the second number. Optionally, the performance evaluation parameter may also be associated with the above-mentioned test temperature.

[0157] In some embodiments, in step 120, the performance difference between the first performance parameter and the second performance parameter may be calculated, and the performance loss may be determined as the ratio between the performance difference and the performance evaluation parameter. That is, the performance loss within a single cycle operation = (first performance parameter - second performance parameter) / performance evaluation parameter.

[0158] The performance evaluation parameter is, for example, between 500 and 1200; further, it may be between 600 and 1000; further, it may be between 800 and 1000. Preferably, the performance evaluation parameter may be 500 or 1000.

[0159] Optionally, the first number and the second number may be less than or equal to 1000; further, they may be less than or equal to 800; further, they may be less than or equal to 500. And, the first number is less than the second number.

[0160] For example, when the first number is equal to 500, the second number is equal to 1000, and the performance evaluation parameter is equal to 1000, the performance loss within a single cycle operation = (performance parameter corresponding to performing 500 cycle operations - performance parameter corresponding to performing 1000 cycle operations) / 1000.

[0161] When considering the rated number of cycle operations and the rated performance parameter, in order to reduce the computational amount and improve the efficiency of calculating the energy loss within a single cycle operation, a preset performance evaluation parameter associated with the number of cycle operations performed by the battery may also be used. For example, in addition to including a first performance parameter corresponding to the battery performing a first number of cycle operations, the cycle parameter may further include the performance evaluation parameter associated with the second number of cycle operations performed by the battery. Optionally, the performance evaluation parameter may also be associated with the above-mentioned test temperature.

[0162] In some embodiments, in step 120, the performance difference between the first performance parameter corresponding to the battery performing the first number of cycle operations and the rated performance parameter may be calculated, and the quantity difference between the rated number of cycle operations and the performance evaluation parameter may be calculated, so as to determine that the performance loss is the ratio of the performance difference to the quantity difference. That is, the performance loss within a single cycle operation = (the first performance parameter - the rated performance parameter) / (the rated number of cycle operations - the performance evaluation parameter).

[0163] The performance evaluation parameter is, for example, between 500 and 1200; further, it may be between 600 and 1000; further, it may be between 800 and 1000. Preferably, the performance evaluation parameter may be 500 or 1000.

[0164] Optionally, the first number may be less than or equal to 1000; further, it may be less than or equal to 800; further, it may be less than or equal to 500.

[0165] For example, when the first number is equal to 500 and the performance evaluation parameter is equal to 1000, the performance loss within a single cycle operation = (the performance parameter corresponding to performing 500 cycle operations - the rated performance parameter) / (the rated number of cycle operations - 1000).

[0166] Hereinafter, in combination with specific examples, how to test the cycle performance of the battery will be described in detail.

[0167] According to formula (1), the average discharge energy loss C per turn of the battery at 45°C can be calculated as C = (Y0 - Y) / (N - N0) = (948 - 910) / (1000 - 500) = 7.6%; considering the rated number of cycles and the rated discharge energy, the battery is charged and discharged cyclically based on the rated power, and the corresponding cycle parameters are obtained. Then, according to formula (2), the average discharge energy loss C per turn of the battery at 45°C can be calculated as C = (Y0 - Y x ) / [X - (N - N0)] = (948 - 500) / [12000 - (1000 - 500)] = 3.896%.

[0168] According to formula (10), the average discharge energy loss C0 per turn of the battery at 25°C can be calculated as C0 = (Y0 - Y) / [(N - N0) * 2] = (948 - 910) / [(1000 - 500) * 2] = 3.8%; considering the rated number of cycles and the rated discharge energy, the battery is charged and discharged cyclically based on the rated power, and the corresponding cycle parameters are obtained. Then, according to formula (11), the average discharge energy loss C0 per turn of the battery at 25°C can be calculated as C0 = (Y0 - Y x) / [X - (N - N0) * 2] = (948 - 500) / [12000 - (1000 - 500) * 2] = 4.07%.

[0169] It can be seen that at a temperature of (45 ± 2) °C, based on the aforementioned steps a) to d) of cyclically charging and discharging the battery, record the discharge energy of the battery after performing 500 charge-discharge cycles and the discharge energy of the battery after performing 1000 charge-discharge cycles, and according to the following formula, it can be calculated:

[0170] △E d = (E d500 - E d1000 ) / 1000;

[0171] △E rd = (E d500 - E rd ) / (C r - 1000);

[0172] Wherein, △E d is the average discharge energy loss per charge-discharge cycle of the battery, △E rd is the average discharge energy loss per charge-discharge cycle calculated based on the number of charge-discharge cycles at the rated power, E d500 is the discharge energy at 500 charge-discharge cycles, E d1000 is the discharge energy at 1000 charge-discharge cycles, E rd is the rated discharge energy, C r is the number of charge-discharge cycles at the rated power.

[0173] Similarly, at a temperature of (45 ± 2) °C, based on the aforementioned steps a) to d) of cyclically charging and discharging the battery, record the charging energy of the battery after performing 500 charge-discharge cycles and the charging energy of the battery after performing 1000 charge-discharge cycles, and according to the following formula, it can be calculated:

[0174] △E c = (E c500 - E c1000 ) / 1000;

[0175] △E rc = (E c500 - E rc ) / (C r - 1000);

[0176] Wherein, △E c is the average charging energy loss per charge-discharge cycle of the battery, △E rc is the average charging energy loss per charge-discharge cycle calculated based on the number of charge-discharge cycles at the rated power, Ec500 is the charging energy at 500 charge-discharge cycles, E c1000 is the charging energy at 1000 charge-discharge cycles, E rc is the rated charging energy, C r is the number of charge-discharge cycles at rated power.

[0177] It can be seen that taking the temperature coefficient β = 2 corresponding to the test temperature of 45°C as an example, 500 charge-discharge cycles and 1000 charge-discharge cycles are carried out respectively under the condition of (45 ± 2)°C. By the above method, the value of this performance evaluation parameter is equal to 1000. Similarly, under other test temperatures and / or other numbers of charge-discharge cycles, the corresponding performance evaluation parameters can also be obtained by the above method.

[0178] According to this performance evaluation parameter, and some of the charge-discharge energies corresponding to 500 charge-discharge cycles, the charge-discharge energies corresponding to 1000 charge-discharge cycles, the rated number of charge-discharge cycles, and the rated charge-discharge performance, the average performance loss of the battery in a single cycle operation can be calculated.

[0179] Optionally, in the embodiments of the present application, the rated charge-discharge energy can also be used as the starting value, with a step of 5% of the rated charge-discharge energy, increasing to the minimum value of the charge-discharge energy of all battery samples in the 500th charge-discharge cycle and the initial charge-discharge energy at 5°C as the guaranteed value of the charge-discharge energy series. According to the following formula, the guaranteed value series of the number of charge-discharge cycles at rated power corresponding to the guaranteed value of the charge-discharge energy series of the battery monomer is calculated:

[0180] C rx =(E d500 -E dx ) / △E rd +1000;

[0181] Wherein, C rx is the guaranteed value series of the number of charge-discharge cycles at rated power, E d500 is the discharge energy at 500 charge-discharge cycles, E dx is the guaranteed value of the discharge energy series, △E d is the average discharge energy loss of the battery in a single charge-discharge cycle.

[0182] Make a data table of the guaranteed value of the charge-discharge energy series of the battery and the guaranteed value series of the number of charge-discharge cycles at rated power as the characteristic relationship table of the guaranteed value series of the battery cycle performance; take the percentage of the rated charge-discharge energy as the horizontal axis and the guaranteed value series of the number of charge-discharge cycles at rated power as the vertical axis, and draw a curve graph of the guaranteed value series of the battery cycle performance as the characteristic curve of the guaranteed value series of the battery cycle performance.

[0183] In the embodiments of the present application, the battery described may be, for example, a battery cell, or a battery module formed by a plurality of battery cells, etc.

[0184] As an example, during the process of testing the performance loss of a battery cell within a single cycle operation, based on the aforementioned steps a) to d) corresponding to the initialization discharge process of the battery cell, the initialization discharge of the battery cell can be carried out, and the temperature of the environmental simulation device can be set to the test temperature of 45°C, and it can be left standing for 5 h at (45 ± 2)°C.

[0185] Then, in step 1, at (45 ± 2)°C, it is charged at a constant power of Prc until the charging cut-off voltage of the battery cell, left standing for 10 min, and the power, time, voltage, temperature, and charging energy are recorded; in step 2, it is discharged at a constant power of Prd until the discharge cut-off voltage of the battery cell, left standing for 10 min, and the power, time, voltage, temperature, and discharge energy are recorded; steps 1 and 2 are repeated until the number of charge and discharge cycles reaches a predetermined number, for example, 1000 times, the connection between the test sample and the charge and discharge device is disconnected, the data sampling line is removed, and the test sample is taken out.

[0186] Repeat all steps until all test samples are completed. Based on the above formula ΔE c =(E c500 -E c1000 ) / 1000 and ΔE rc =(E c500 -E rc ) / (C r -1000), the average value of the charge and discharge energy loss per cycle of each test sample, and the average value of the charge energy loss per cycle based on the rated charge energy are calculated respectively; and, based on the above formula ΔE d =(E d500 -E d1000 ) / 1000 and ΔE rd =(E d500 -E rd ) / (C r -1000), the average value of the discharge energy loss per cycle of each test sample, and the average value of the discharge energy loss per cycle based on the rated discharge energy are calculated respectively.

[0187] As another example, during the process of testing the performance loss of a battery module within a single cycle operation, based on the aforementioned steps a) to d) corresponding to the initialization discharge process of the battery module, the initialization discharge of the battery module can be carried out, and the temperature of the environmental simulation device can be set to the test temperature of 45°C, and it can be left standing for 5 h at (45 ± 2)°C.

[0188] Next, in step 1, at (45±2)°C, charge at a constant power of Prc until the priority arrival value among the charging cut-off voltages of the battery module and any battery cell is reached, let it stand for 10 min, and record the power, time, voltage, temperature, and charging energy; in step 2, discharge at a constant power of Prd until the priority arrival value among the discharge cut-off voltages of the battery module and any battery cell is reached, let it stand for 10 min, and record the power, time, voltage, temperature, and discharge energy; repeat steps 1 and 2 until the number of charge-discharge cycles reaches a predetermined number, such as 1000 times, disconnect the connection between the test sample and the charge-discharge device, remove the data sampling line, and take out the test sample.

[0189] Repeat all steps until all test samples are tested. Based on the above formula △E c =(E c500 -E c1000 ) / 1000 and △E rc =(E c500 -E rc ) / (C r -1000), calculate the average value of the charge-discharge energy loss per single cycle and the average value of the charge energy loss per single cycle based on the rated charge energy respectively; and, based on the above formula △E d =(E d500 -E d1000 ) / 1000 and △E rd =(E d500 -E rd ) / (C r -1000), calculate the average value of the discharge energy loss per single cycle and the average value of the discharge energy loss per single cycle based on the rated discharge energy respectively.

[0190] The test method of the embodiment of the present application is described in detail above. Next, in combination with Figure 7 and Figure 8 the test device of the embodiment of the present application will be described in detail. The technical features described in the method embodiment are applicable to the following device embodiment.

[0191] Figure 6 is a schematic block diagram of the test device for the battery of the embodiment of the present application. As Figure 7 shown, the test device 200 includes an acquisition module 210 and a processing module 220. Among them, the acquisition module 210 is used to obtain the cycle parameters of the battery, and the cycle parameters include the performance parameters of the battery corresponding to the execution of a predetermined number of cycle operations; the processing module 220 is used to determine the performance loss of the battery within a single cycle operation according to the cycle parameters.

[0192] In some embodiments, the number of the cycle operations includes the number of charge-discharge cycles or the number of storage days.

[0193] In some embodiments, the performance parameter includes energy, and the performance loss includes energy loss; alternatively, the performance parameter includes capacity, and the performance loss includes capacity loss; alternatively, the performance parameter includes internal resistance, and the performance loss includes internal resistance loss.

[0194] In some embodiments, the processing module 220 is specifically configured to determine the performance loss of the battery at the standard temperature according to the cycle parameter and the temperature coefficient corresponding to the current test temperature, where the test temperature is greater than the standard temperature.

[0195] In some embodiments, the temperature coefficient is between 1 and 100, or the temperature coefficient is between 1 and 50, or the temperature coefficient is between 1 and 10, or the temperature coefficient is between 1 and 5, or the temperature coefficient is 2.

[0196] In some embodiments, the acquisition module 210 is specifically configured to obtain the cycle parameter at a predetermined test temperature, where the test temperature is greater than the standard temperature, and the performance loss is the performance loss at the standard temperature.

[0197] In some embodiments, the test temperature is between 30°C and 60°C, or the test temperature is between 43°C and 47°C, or the test temperature is between 53°C and 57°C, or the test temperature is 45°C or 55°C.

[0198] In some embodiments, the cycle parameter includes a first performance parameter corresponding to the battery performing a first number of cycle operations and a second performance parameter corresponding to the battery performing a second number of cycle operations, and the second number is greater than the first number.

[0199] In some embodiments, the processing module 220 is specifically configured to calculate the performance difference between the first performance parameter and the second performance parameter, and the quantity difference between the second number and the first number; and determine the performance loss according to the ratio of the performance difference to the quantity difference.

[0200] In some embodiments, the processing module 220 is specifically configured to calculate the product of the quantity difference and the temperature coefficient; and determine the performance loss as the ratio of the performance difference to the product.

[0201] In some embodiments, the first number and the second number are the number of charge-discharge cycles, the first number is 500, and the second number is 1000.

[0202] In some embodiments, the cycle parameter further includes a performance evaluation parameter associated with the predetermined quantity, and the processing module 220 is specifically configured to: calculate a performance difference between the first performance parameter and the second performance parameter; determine that the performance loss is a ratio between the performance difference and the performance evaluation parameter.

[0203] In some embodiments, the first quantity is 500, the second quantity is 1000, and the performance evaluation parameter is 1000.

[0204] In some embodiments, the performance parameter is charging energy, and the performance loss is charging energy loss.

[0205] In some embodiments, the performance parameter is discharging energy, and the performance loss is discharging energy loss.

[0206] In some embodiments, the processing module 220 is specifically configured to determine the performance loss according to the cycle parameter, the rated cycle operation quantity of the battery, and the rated performance parameter of the battery.

[0207] In some embodiments, the processing module 220 is specifically configured to calculate a performance difference between a first performance parameter corresponding to the battery performing a first quantity of cycle operations and the rated performance parameter; calculate a first quantity difference between the second quantity of cycle operations performed by the battery and the first quantity, and a second quantity difference between the rated cycle operation quantity and the first quantity difference, where the second quantity is greater than the first quantity; determine that the performance loss is a ratio between the performance difference and the second quantity difference.

[0208] In some embodiments, the processing module 220 is specifically configured to calculate a first quantity difference between the second quantity and the first quantity; calculate a product of the first quantity difference and a temperature coefficient; determine that the second quantity difference is a difference between the rated cycle operation quantity and the product.

[0209] In some embodiments, the first quantity and the second quantity are the number of charge and discharge cycles, the first quantity is 500, and the second quantity is 1000.

[0210] In some embodiments, the cycle parameter further includes a performance evaluation parameter associated with the predetermined quantity, and the processing module 220 is specifically configured to calculate a performance difference between a first performance parameter corresponding to the battery performing a first quantity of cycle operations and the rated performance parameter; calculate a quantity difference between the rated cycle operation quantity and the performance evaluation parameter; determine that the performance loss is a ratio between the performance difference and the quantity difference.

[0211] In some embodiments, the first quantity is 500 and the performance evaluation parameter is 1000.

[0212] In some embodiments, the performance parameter is the charging energy and the performance loss is the charging energy loss.

[0213] In some embodiments, the performance parameter is the discharging energy and the performance loss is the discharging energy loss.

[0214] In some embodiments, the number of cycle operations is the number of charge-discharge cycles. Each charge-discharge cycle sequentially includes the following processes: charging the battery to a charging cut-off voltage at a first constant power, standing for a predetermined duration, discharging the battery to a discharging cut-off voltage at a second constant power, and standing for a preset duration.

[0215] It should be understood that for the specific manner in which the test device 200 controls the charge and discharge of multiple battery packs and the beneficial effects produced, reference may be made to the relevant descriptions in the method embodiments. For the sake of simplicity, they will not be elaborated here.

[0216] The present application further provides a test device 300 for a battery, as Figure 8 shown. The test device 300 includes a processor 310 and a memory 320. The memory 320 is used to store instructions, and the processor 310 is used to read the instructions and execute the foregoing test method 100 of various embodiments of the present application based on the instructions. The memory 320 may be a separate device independent of the processor 310 or may be integrated in the processor 310.

[0217] Optionally, as Figure 8 shown, the test device 300 may further include a transceiver 330. The processor 310 may control the transceiver 330 to communicate with other devices. For example, it may send information to other devices or receive information sent by other devices.

[0218] The present application further provides a test system for a battery, including a battery, a charge-discharge device, and the test device or test equipment for the battery described in any of the foregoing embodiments. The charge-discharge device is used to charge and discharge the battery, and the test device or the test equipment is used to test the performance loss of the battery during the charge and discharge process.

[0219] The present application further provides a computer-readable storage medium for storing a computer program. When the computer program is executed by a computing device, the computing device is enabled to implement the test method 100 for the battery described in any of the foregoing embodiments. Optionally, the computer program may be the computer program in the test device for the battery.

[0220] It should be understood that the processor in the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiments can be completed by the integrated logic circuit in the hardware of the processor or the instructions in the form of software. The above processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by the hardware decoding processor, or executed and completed by the combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0221] The memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include but not be limited to these and any other suitable types of memory.

[0222] It should be noted that, on the premise of no conflict, the various embodiments described in the present application and / or the technical features in each embodiment can be combined arbitrarily, and the technical solutions obtained after combination should also fall within the protection scope of the present application.

[0223] In the embodiments of the present application, the magnitudes of the sequence numbers of the various steps do not mean the order of execution. The order of execution of the various steps should be determined according to their functions and internal logics, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0224] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0225] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple 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 displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0226] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

[0227] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for testing a battery, characterized in that, The described test method includes: Obtaining the cycling parameters of the battery, where the cycling parameters include the performance parameters of the battery corresponding to the execution of a predetermined number of cycling operations; Determining the performance loss of the battery within a single cycling operation based on the cycling parameters.

2. The test method according to claim 1, wherein The number of the cycling operations includes the number of charge-discharge cycles or the number of storage days.

3. The test method according to claim 1, characterized in that, The performance parameters include energy, and the performance loss includes energy loss; alternatively, the performance parameters include capacity, and the performance loss includes capacity loss; alternatively, the performance parameters include internal resistance, and the performance loss includes internal resistance loss.

4. The test method according to any one of claims 1 to 3, characterized in that The determining the performance loss of the battery within a single cycling operation based on the cycling parameters includes: Determining the performance loss of the battery at the standard temperature based on the cycling parameters and the temperature coefficient corresponding to the current test temperature, where the test temperature is greater than the standard temperature.

5. The testing method according to claim 4, wherein The temperature coefficient is between 1 and 100, or between 1 and 50, or between 1 and 10, or between 1 and 5, or the temperature coefficient is 2.

6. The test method according to claim 4, characterized in that The test temperature is between 30°C and 60°C, or between 43°C and 47°C, or between 53°C and 57°C, or the test temperature is 45°C or 55°C.

7. The test method according to any one of claims 1 to 3, characterized in that, The obtaining the cycling parameters of the battery includes: Obtaining the cycling parameters at a predetermined test temperature, where the test temperature is greater than the standard temperature, and the performance loss is the performance loss at the standard temperature.

8. The test method according to any one of claims 1 to 3, characterized in that, The cycling parameters include the first performance parameters corresponding to the battery's execution of a first number of cycling operations and the second performance parameters corresponding to the battery's execution of a second number of cycling operations, and the second number is greater than the first number.

9. The test method according to claim 8, wherein The determining the performance loss of the battery within a single cycling operation based on the cycling parameters includes: Calculating the performance difference between the first performance parameters and the second performance parameters, and the quantity difference between the second number and the first number; Determining the performance loss based on the ratio of the performance difference to the quantity difference.

10. The test method according to claim 9, wherein The determining the performance loss based on the ratio between the performance difference and the quantity difference includes: Calculating the product of the quantity difference and the temperature coefficient; Determining the performance loss as the ratio of the performance difference to the product.

11. The test method according to claim 9, characterized in that, The first number and the second number are the number of charge-discharge cycles, the first number is 500, and the second number is 1000.

12. The test method according to claim 8, characterized in that, The cycling parameters further include performance evaluation parameters associated with the predetermined number. The determining the performance loss of the battery within a single cycling operation based on the cycling parameters includes: Calculating the performance difference between the first performance parameters and the second performance parameters; Determining the performance loss as the ratio between the performance difference and the performance evaluation parameters.

13. The testing method according to claim 12, characterized in that, The first number is 500, the second number is 1000, and the performance evaluation parameter is 1000.

14. The test method according to claim 8, wherein The performance parameter is charging energy, and the performance loss is charging energy loss.

15. The testing method according to claim 8, characterized in that, The performance parameter is the discharge energy, and the performance loss is the discharge energy loss.

16. The test method according to any one of claims 1 to 3, characterized in that Determining the performance loss of the battery within a single cycle operation according to the cycle parameter includes: Determining the performance loss according to the cycle parameter, the rated cycle operation number of the battery, and the rated performance parameter of the battery.

17. The test method according to claim 16, characterized in that, Determining the performance loss according to the cycle parameter, the rated cycle operation number of the battery, and the rated performance parameter of the battery includes: Calculating the performance difference between the first performance parameter corresponding to the battery performing the first number of cycle operations and the rated performance parameter; Calculating the first quantity difference between the second quantity of the cycle operations performed by the battery and the first quantity, and the second quantity difference between the rated cycle operation number and the first quantity difference, where the second quantity is greater than the first quantity; Determining the performance loss as the ratio of the performance difference to the second quantity difference.

18. The test method according to claim 17, wherein Calculating the first quantity difference between the second quantity of the cycle operations performed by the battery and the first quantity, and the second quantity difference between the rated cycle operation number and the first quantity difference includes: Calculating the first quantity difference between the second quantity and the first quantity; Calculating the product of the first quantity difference and the temperature coefficient; Determining the second quantity difference as the difference between the rated cycle operation number and the product.

19. The test method according to claim 17, wherein The first quantity and the second quantity are the number of charge-discharge cycles, the first quantity is 500, and the second quantity is 1000.

20. The test method according to claim 16, wherein The cycle parameter further includes a performance evaluation parameter associated with the predetermined quantity. Determining the performance loss of the battery within a single cycle operation according to the cycle parameter includes: Calculating the performance difference between the first performance parameter corresponding to the battery performing the first number of cycle operations and the rated performance parameter; Calculating the quantity difference between the rated cycle operation number and the performance evaluation parameter; Determining the performance loss as the ratio of the performance difference to the quantity difference.

21. The test method according to claim 20, characterized in that, The first quantity is 500, and the performance evaluation parameter is 1000.

22. The test method according to claim 17, wherein The performance parameter is the charge energy, and the performance loss is the charge energy loss.

23. The testing method according to claim 17, characterized in that, The performance parameter is the discharge energy, and the performance loss is the discharge energy loss.

24. The test method according to any one of claims 1 to 3, characterized in that The number of the cycle operations is the number of charge-discharge cycles. Wherein, each charge-discharge cycle sequentially includes the following processes: Charging the battery to the charge cut-off voltage at a first constant power, standing for a predetermined duration, discharging the battery to the discharge cut-off voltage at a second constant power, and standing for a preset duration.

25. A test device for a battery, characterized in that, The test device includes: An acquisition module for acquiring the cycle parameter of the battery, where the cycle parameter includes the performance parameter of the battery corresponding to performing a predetermined number of cycle operations; A processing module for determining the performance loss of the battery within a single cycle operation according to the cycle parameter.

26. The testing device according to claim 25, characterized in that, The number of the cycle operations includes the number of charge-discharge cycles or the number of storage days.

27. The test device according to claim 25, characterized in that, The performance parameters include energy, and the performance losses include energy losses; or, the performance parameters include capacity, and the performance losses include capacity losses; or, the performance parameters include internal resistance, and the performance losses include internal resistance losses.

28. The test device according to any one of claims 25 to 27, characterized in that The processing module is specifically configured to: Determine the performance loss of the battery at the standard temperature according to the cycle parameters and the temperature coefficient corresponding to the current test temperature, where the test temperature is greater than the standard temperature.

29. The test device according to claim 28, wherein The temperature coefficient is between 1 and 100, or the temperature coefficient is between 1 and 50, or the temperature coefficient is between 1 and 10, or the temperature coefficient is between 1 and 5, or the temperature coefficient is 2.

30. The test device according to claim 28, characterized in that, The test temperature is between 30°C and 60°C, or the test temperature is between 43°C and 47°C, or the test temperature is between 53°C and 57°C, or the test temperature is 45°C or 55°C.

31. The test device according to any one of claims 25 to 27, characterized in that The acquisition module is specifically configured to, Obtain the cycle parameters at a predetermined test temperature, where the test temperature is greater than the standard temperature, and the performance loss is the performance loss at the standard temperature.

32. The test device according to any one of claims 25 to 27, characterized in that, The cycle parameters include a first performance parameter corresponding to the battery performing a first number of cycle operations, and a second performance parameter corresponding to the battery performing a second number of cycle operations, where the second number is greater than the first number.

33. The test device according to claim 32, wherein The processing module is specifically configured to: Calculate the performance difference between the first performance parameter and the second performance parameter, and the quantity difference between the second number and the first number; Determine the performance loss according to the ratio of the performance difference to the quantity difference.

34. The test device according to claim 33, characterized in that, The processing module is specifically configured to: Calculate the product of the quantity difference and the temperature coefficient; Determine that the performance loss is the ratio of the performance difference to the product.

35. The test device according to claim 33, characterized in that, The first number and the second number are the number of charge-discharge cycles, the first number is 500, and the second number is 1000.

36. The test device according to claim 32, wherein The cycle parameters further include a performance evaluation parameter associated with the predetermined quantity, and the processing module is specifically configured to: Calculate the performance difference between the first performance parameter and the second performance parameter; Determine that the performance loss is the ratio between the performance difference and the performance evaluation parameter.

37. The testing device according to claim 36, wherein The first number is 500, the second number is 1000, and the performance evaluation parameter is 1000.

38. The test device according to claim 32, wherein, The performance parameter is charging energy, and the performance loss is charging energy loss.

39. The test device according to claim 32, wherein The performance parameter is discharging energy, and the performance loss is discharging energy loss.

40. The test device according to any one of claims 25 to 27, characterized in that The processing module is specifically configured to: Determine the performance loss according to the cycle parameters, the rated cycle operation quantity of the battery, and the rated performance parameters of the battery.

41. The test device according to claim 40, wherein The processing module is specifically configured to: Calculate the performance difference between the first performance parameter corresponding to the battery performing a first number of cycle operations and the rated performance parameter; Calculate a first quantity difference between a second quantity of cyclic operations performed by the battery and the first quantity, and a second quantity difference between the rated cyclic operation quantity and the first quantity difference, where the second quantity is greater than the first quantity; Determine that the performance loss is the ratio of the performance difference to the second quantity difference.

42. The testing device according to claim 41, wherein Specifically, the processing module is configured to: Calculate a first quantity difference between the second quantity and the first quantity; Calculate the product of the first quantity difference and the temperature coefficient; Determine that the second quantity difference is the difference between the rated cyclic operation quantity and the product.

43. The test device according to claim 41, wherein, The first quantity and the second quantity are the number of charge-discharge cycles, the first quantity is 500, and the second quantity is 1000.

44. The test device according to claim 40, wherein The cyclic parameter further includes a performance evaluation parameter associated with the predetermined quantity. Specifically, the processing module is configured to: Calculate a performance difference between a first performance parameter corresponding to the battery performing a first quantity of cyclic operations and the rated performance parameter; Calculate a quantity difference between the rated cyclic operation quantity and the performance evaluation parameter; Determine that the performance loss is the ratio of the performance difference to the quantity difference.

45. The test device according to claim 44, wherein The first quantity is 500, and the performance evaluation parameter is 1000.

46. The test device according to claim 41, wherein The performance parameter is charging energy, and the performance loss is charging energy loss.

47. The test device according to claim 41, wherein The performance parameter is discharging energy, and the performance loss is discharging energy loss.

48. The test device according to any one of claims 25 to 27, characterized in that The quantity of the cyclic operations is the number of charge-discharge cycles. Among them, each charge-discharge cycle sequentially includes the following processes: Charge the battery to a charge cut-off voltage at a first constant power, stand for a predetermined duration, discharge the battery to a discharge cut-off voltage at a second constant power, and stand for a preset duration.

49. A test device for a battery, characterized in that, It includes a processor and a memory. The memory is used to store instructions, and the processor is used to execute the instructions to implement the test method according to any one of claims 1 to 24.

50. A test system for a battery, characterized in that, The test system includes: A battery; A charge-discharge device for charging and discharging the battery; and The test device according to claim 49, for testing the performance loss of the battery during the charging and discharging process.

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