Lithium ion battery capacity climbing correction method and system

Abstract

The embodiment of the invention provides a lithium ion battery capacity climbing correction method and system, and the method comprises the steps: recording the initial battery data of a target battery in the first charging and discharging process, and the battery data comprises the discharge end temperature and the discharge capacity; based on the initial battery data, carrying out a capacity climbing elimination test on the target battery, and recording a correction coefficient under the capacity climbing elimination test; adjusting the temperature data, and recording gradient battery data of the target battery under different temperatures and standard battery data of the target battery under the reference temperature data; fitting a relation model between the discharge capacity and the discharge end temperature by taking the standard battery data as a standard condition and the gradient battery data as a variable, and calculating the benchmarking capacity of the target battery at the target compensation temperature based on the relation model; and calculating initial capacity correction data by taking the initial discharge end temperature and the standard discharge capacity as input data and combining the relation model and the correction coefficient.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular, to a method and system for correcting the capacity ramp of a lithium-ion battery. Background Art

[0002] As a high-energy battery technology, lithium-ion batteries are widely used in electronic products, energy storage containers, new energy electric vehicles and other fields, and have great market demand.

[0003] However, during the cycling process of lithium-ion batteries, as the cycling progresses, the capacity first climbs up for a period of time, reaches the highest point, and then gradually decreases, that is, the cycling ramp phenomenon occurs. This is because the positive electrode is not fully utilized. The ramp phenomenon will cause the capacity of the lithium battery during grading to not be fully exerted, and the grading capacity is relatively low. Some batteries can meet the capacity design after the grading process. A small part of the batteries have a capacity slightly lower than the design value due to the capacity ramp problem. At this time, re-grading the battery will make it difficult to ensure the consistency of the voltage difference between the first-graded battery and the multi-graded battery, and multi-graded charging will cause the battery manufacturing cycle to become longer, which is not conducive to industrial production. Summary of the Invention

[0004] In view of the problems existing in the prior art, an embodiment of the present invention provides a method and system for correcting the capacity ramp of a lithium-ion battery.

[0005] An embodiment of the present invention provides a method for correcting the capacity ramp of a lithium-ion battery, the method comprising: Recording initial battery data during the first charge and discharge process of a target battery, the battery data including the end-of-discharge temperature and the discharge capacity; Based on the initial battery data, performing a capacity ramp elimination test on the target battery, and recording the correction coefficient under the capacity ramp elimination test; Adjusting the temperature data, recording the gradient battery data of the target battery at different temperatures, and the standard battery data of the target battery at the reference temperature data; Taking the standard battery data as the standard condition and the gradient battery data as variables, fitting a relationship model between the discharge capacity and the end-of-discharge temperature, and calculating the target capacity of the target battery at the target compensation temperature based on the relationship model; Taking the initial end-of-discharge temperature and the standard discharge capacity as input data, combining the relationship model and the correction coefficient, and calculating the initial capacity correction data.

[0006] In one embodiment, the method further comprises: Placing the target battery at rest at the reference temperature, and discharging it at a constant current at the first rate until the cut-off voltage; Rest the target battery again and charge it at a constant current and constant voltage at the second rate until the cut-off current is reached; Discharge and charge the process several times in a cycle, record the cycle discharge capacity in each discharge and charge cycle, compare the cycle discharge capacity with the initial discharge capacity, and calculate the correction factor.

[0007] In one embodiment, the method further includes: Based on a preset functional relationship, compare the variables with the standard conditions in sequence, and quantitatively calculate the constants in the functional relationship. The functional relationship is: where C is the discharge capacity in the gradient battery data, is the discharge capacity in the standard battery data, x is the discharge end temperature in the gradient battery data, and a, b, and c are constants.

[0008] In one embodiment, the method further includes: Adjust the functional relationship to a second relationship associated with the capacity ramp elimination experiment. The second relationship is: where n is the number of cycles in the capacity ramp elimination test and t is the correction factor.

[0009] In one embodiment, the method further includes: When calculating the initial battery data, gradient battery data, and standard battery data, calculate the average value of several groups of the target battery.

[0010] An embodiment of the present invention provides a lithium-ion battery capacity ramp correction system. The system includes: A recording module for recording the initial battery data during the first charge and discharge process of the target battery. The battery data includes the discharge end temperature and the discharge capacity; A test module for performing a capacity ramp elimination test on the target battery based on the initial battery data and recording the correction factor under the capacity ramp elimination test; A temperature module for adjusting the temperature data, recording the gradient battery data of the target battery at different temperatures, and the standard battery data of the target battery at the reference temperature; A model module for using the standard battery data as the standard condition and the gradient battery data as the variable to fit the relationship model between the discharge capacity and the discharge end temperature, and calculating the target capacity of the target battery at the target compensation temperature based on the relationship model; An initial capacity adjustment module, configured to use the initial discharge end temperature and the standard discharge capacity as input data, and in combination with the relationship model and the correction coefficient, calculate the initial capacity correction data.

[0011] In one embodiment, the system further includes: A discharge module, configured to place the target battery at a reference temperature and perform constant current discharge at a first rate until the cut-off voltage. A charging module, configured to place the target battery at rest again and perform constant current and constant voltage charging at a second rate until the cut-off current. A cycling module, configured to cycle the discharge and charge processes a certain number of times, record the cyclic discharge capacity in each discharge and charge cycle, compare the cyclic discharge capacity with the initial discharge capacity, and calculate the correction coefficient.

[0012] In one embodiment, the system further includes: A calculation module, configured to calculate the average value of several groups of the target batteries when calculating the initial battery data, the gradient battery data, and the standard battery data.

[0013] An embodiment of the present invention provides an electronic device, including a processor and a memory; The processor is connected to the memory; The memory is configured to store executable program code; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to execute the method described in one or more embodiments.

[0014] An embodiment of the present invention provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned lithium-ion battery capacity ramp correction method are implemented.

[0015] In view of the above, in one or more embodiments of this specification, initial battery data during the first charge and discharge process of the target battery is recorded. The battery data includes the end - discharge temperature and the discharge capacity. Based on the initial battery data, a capacity ramp - elimination test is performed on the target battery, and the correction factor under the capacity ramp - elimination test is recorded. The temperature data is adjusted, and the gradient battery data of the target battery at different temperatures and the standard battery data of the target battery at the reference temperature are recorded. Taking the standard battery data as the standard condition and the gradient battery data as variables, a relationship model between the discharge capacity and the end - discharge temperature is fitted, and the reference capacity of the target battery at the target compensation temperature is calculated based on the relationship model. Using the initial end - discharge temperature and the standard discharge capacity as input data, combined with the relationship model and the correction factor, the initial capacity correction data is calculated. This can timely correct the battery capacity when the battery shows a cyclic ramp phenomenon, and can also perform basic correction on the initial capacity of the battery, improving the consistency of battery use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a flowchart of a method for correcting the capacity ramp of a lithium - ion battery provided by an embodiment of this specification.

[0018] Figure 2 It is a flowchart of a capacity ramp - elimination test provided by an embodiment of this specification.

[0019] Figure 3 It is a graph showing the change of the cell capacity change rate with the number of cycles provided by an embodiment of this specification.

[0020] Figure 4 It is a graph showing the change of the capacity correction data with the number of cycles provided by an embodiment of this specification.

[0021] Figure 5 It is a schematic diagram of the gradient battery data of a target battery provided by an embodiment of this specification.

[0022] Figure 6 It is a schematic diagram of the standard battery data of a target battery provided by an embodiment of this specification.

[0023] Figure 7 It is a schematic diagram of the test data for fitting a quadratic model provided by an embodiment of this specification.

[0024] Figure 8 It is a schematic diagram of a fitting line graph provided by an embodiment of this specification.

[0025] Figure 9 It is a schematic diagram before and after real-time capacity correction provided by an embodiment of this specification.

[0026] Figure 10 It is a schematic diagram before and after initial capacity correction provided by an embodiment of this specification.

[0027] Figure 11 It is a schematic structural diagram of a lithium-ion battery capacity ramp correction system provided by an embodiment of this specification.

[0028] Figure 12 It is a schematic structural diagram of an electronic device provided by an embodiment of this specification. Detailed implementation manners

[0029] Now, the subject matter described herein will be discussed with reference to example embodiments. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thereby implement the subject matter described herein, and is not a limitation on the protection scope, applicability, or examples set forth in the claims. The functions and arrangements of the elements discussed can be changed without departing from the protection scope of the content of this specification. Each example can omit, substitute, or add various processes or components as needed. For example, the methods described can be performed in a different order from the described order, and each step can be added, omitted, or combined. Additionally, the features described relative to some examples can also be combined in other examples.

[0030] As used herein, the term "including" and its variants represent open terms, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" and "an embodiment" mean "at least one embodiment". The term "another embodiment" means "at least one other embodiment". The terms "first", "second", etc. can refer to different or the same objects. Other definitions, whether explicit or implicit, may be included below. Unless explicitly specified in the context, the definition of a term is consistent throughout the specification.

[0031] As Figure 1 shown, an embodiment of the present invention provides a method for correcting the capacity ramp of a lithium-ion battery, including: Step S102, record the initial battery data during the first charge and discharge process of the target battery, where the battery data includes the temperature at the end of discharge and the discharge capacity.

[0032] Specifically, select a number of target batteries of the same model from the same batch as the test samples for the subsequent steps. The sample size can be as large as possible, such as greater than or equal to 30, so as to ensure the confidence of the data and detect that the samples are free from deformation, contamination, and electrolyte leakage. Then, perform the first charge and discharge on the target batteries. Among them, the first charge and discharge process may include keeping the user at a reference temperature (such as 25 °C) for constant temperature standing, and then performing charge and discharge on the target batteries to determine the initial battery data of the target batteries under the condition of not being used, including the initial discharge end temperature and the initial discharge capacity of the batteries.

[0033] Step S104, based on the initial battery data, perform a capacity ramp elimination test on the target battery and record the correction factor under the capacity ramp elimination test.

[0034] Specifically, after recording the initial battery data of the target battery, perform a capacity ramp elimination test on the target battery. Among them, the capacity ramp elimination test includes the following steps: S201, let the target lithium-ion battery stand at the reference temperature (25 ± 3 °C) for a period of time; S202, perform constant current discharge on the target lithium-ion battery at a certain specific rate until the discharge cut-off voltage; S203, let the target lithium-ion battery stand for another period of time; S204, perform constant current and constant voltage charging on the target lithium-ion battery at a certain specific rate (different from the discharge voltage) until the charging cut-off current; S205, perform 10 cycles on the battery under the above conditions to accelerate the ramp and obtain the attenuation law of the target battery, and record the discharge capacity of each cycle; According to the above method, at the reference temperature (25 ± 3 °C), the discharge capacities C0, C1, ··· C of each battery can be obtained n , the difference in capacity of the same battery for each cycle can be expressed as △C = C n - C n-1 , and then according to the formula fitting, C n = C0 * (1 + t) n , where C0 is the starting discharge capacity, C n is the capacity after n cycles, and t is the correction factor, so as to record the correction factor under the capacity ramp elimination test. Among them, during the cyclic ramp process, the curve of the change rate of the cell capacity with the number of cycles is as shown in Figure 3 , and the curve of the capacity correction data under the correction factor with the number of cycles is as shown in Figure 4 .

[0035] Step S106: Adjust the temperature data, record the gradient cell data of the target cell at different temperatures, and the standard cell data of the target cell at the reference temperature data.

[0036] Specifically, adjust the temperature data, determine the characteristic model of the target cell at different temperatures and the standard condition capacity at the reference temperature. Among them, the steps for establishing the characteristic model at different temperatures include: Under different constant temperature conditions, conduct capacity tests on each cell: Let the target lithium-ion battery stand for a period of time under different constant temperature oven conditions; Charge the target lithium-ion battery at a constant current and constant voltage to 3.65V at a rate of 0.5C and cut off the current at 0.05C; Let the target lithium-ion battery stand for another period of time; Discharge the target lithium-ion battery at a constant current to a cut-off voltage of 2.5V at a rate of 0.33C; Adjust the temperature of the constant temperature oven to 19°C, 22°C, 25°C, 28°C, 31°C, 33°C, 35°C, etc. in sequence and repeat all temperature gradients according to the above conditions; Record the temperature T / °C at the battery top cover or the large surface of the battery cell and the capacity C / Ah of the battery for each cell under different constant temperature conditions.

[0037] Among them, the test data of the above steps can be as Figure 5 shown.

[0038] Furthermore, the standard condition capacity of the target cell at the reference temperature is: Under the condition of 25±3°C, conduct capacity tests on each cell: Let the target lithium-ion battery stand for a period of time in the constant temperature oven; Charge the target lithium-ion battery at a constant current and constant voltage to 3.65V at a rate of 0.5C and cut off the current at 0.05C; Let the target lithium-ion battery stand for another period of time; Discharge the target lithium-ion battery at a constant current to a cut-off voltage of 2.5V at a rate of 0.33C; Record the temperature T / °C at the battery top cover or the large surface of the battery cell and the capacity C / Ah of the battery for each cell.

[0039] Under the condition of 25±3°C, the constant volume capacity C i of each cell is the discharge capacity of each discharge step under this constant temperature condition. Thus, the temperature at the end of discharge and the discharge capacity under standard conditions (25±3°C) are obtained, where , , where n is the number of cycles. Among them, the test data of the standard condition capacity at the reference temperature in the above steps can be as Figure 6 shown.

[0040] Step S108: Taking the standard battery data as the standard condition and the gradient battery data as variables, fitting a relationship model between the discharge capacity and the discharge end temperature, and calculating the reference capacity of the target battery at the target compensation temperature based on the relationship model.

[0041] Specifically, abnormal data in the gradient battery data is proposed. Then, taking the standard battery data, that is, the discharge end temperature at 25°C and the discharge capacity as the standard condition and the gradient battery data as variables, a temperature-capacity quadratic model of the discharge end temperature and the discharge capacity is obtained by fitting. Among them, the fitting process may include: using the functional relationship: Based on this, combined with the data standard condition, parameters a, b, and c are calculated for the variable. The calculation method can be, for example, by the least squares method. Thus, the influence of the discharge end temperature on the discharge end capacity is quantified. Among them, C is the discharge capacity in the gradient data, and x is the discharge end temperature. Among them, the test data for fitting the quadratic model in the above steps can be as Figure 7 shown.

[0042] Furthermore, after determining the temperature-capacity quadratic model, the functional relationship can be transformed to obtain the reference capacity of the target battery at the target compensation temperature.

[0043] The reference capacity compensation formula is: According to the reference capacity compensation formula, the reference capacity of the target battery at the target compensation temperature can be calculated. In the test data such as Figure 7 , the fitting line graph that can be calculated can be as Figure 8 shown, C1 / C0 = 0.9179 + 0.004422 cell temperature (X) - 0.000058 cell temperature^2.

[0044] Among them, the icons before and after correction can be as Figure 9 shown, and in Figure 9Among them, the horizontal axis represents the battery capacity value in Ah, and the vertical axis represents the frequency density, that is, the probability density function. Before correction, the data was scattered and showed a right-skewed distribution (the long tail extended towards high capacity), with a standard deviation as high as 1.737, indicating significant differences in battery capacities (such as a span of 204 - 210 Ah). After correction, the data was highly concentrated, showing an approximately normal distribution, with the mean increased to 209.3 Ah and the standard deviation decreased to 0.2836 (the fluctuation range was compressed within ±0.5 Ah), thereby avoiding secondary grading and improving the consistency of the battery pack and extending the life of the entire package.

[0045] Step S110: Using the initial discharge end temperature and the standard discharge capacity as input data, combined with the relationship model and the correction coefficient, calculate the initial capacity correction data.

[0046] Specifically, when correcting the initial capacity, it is also necessary to combine the capacity ramp elimination result, the correction coefficient, and the number of cycles. The specific relationship formula is: Among them, is the starting capacity at the end of discharge at 25°C, a, b, and c are constant coefficients, x is the initial discharge end temperature, n is the number of cycles, and t is the correction coefficient.

[0047] Furthermore, the graphs before and after the initial capacity correction can be as Figure 10 shown. In Figure 10 Among them, the horizontal axis represents the battery capacity value in Ah, and the vertical axis represents the frequency density, that is, the probability density function. Before correction, the data was scattered and showed a right-skewed distribution (the long tail extended towards high capacity), with a standard deviation as high as 1.737, indicating significant differences in battery capacities (such as a span of 204 - 210 Ah). After correction, the data was highly concentrated, showing an approximately normal distribution, with the standard deviation decreased to 0.2798, and the capacity fluctuation range was compressed within ±0.5 Ah, thereby avoiding secondary grading and improving the consistency of the battery pack and extending the life of the entire package.

[0048] A method for correcting the capacity ramp of a lithium-ion battery provided by an embodiment of the present invention records the initial battery data during the first charge and discharge process of a target battery, where the battery data includes the end-of-discharge temperature and the discharge capacity. Based on the initial battery data, a capacity ramp elimination test is performed on the target battery, and the correction coefficient under the capacity ramp elimination test is recorded. The temperature data is adjusted, and the gradient battery data of the target battery at different temperatures and the standard battery data of the target battery at the reference temperature are recorded. Taking the standard battery data as the standard condition and the gradient battery data as variables, a relationship model between the discharge capacity and the end-of-discharge temperature is fitted, and the reference capacity of the target battery at the target compensation temperature is calculated based on the relationship model. Using the initial end-of-discharge temperature and the standard discharge capacity as input data, combined with the relationship model and the correction coefficient, the initial capacity correction data is calculated. This can timely correct the battery capacity when the battery shows a cyclic ramp phenomenon, and can also perform basic correction on the initial capacity of the battery, improving the consistency of battery use.

[0049] Please refer to Figure 11 , Figure 11 which is a schematic structural diagram of a lithium-ion battery capacity ramp correction system provided by an embodiment of the present application. As Figure 11 shown, the system includes: A recording module S1102, configured to record the initial battery data during the first charge and discharge process of a target battery, where the battery data includes the end-of-discharge temperature and the discharge capacity; An experiment module S1104, configured to perform a capacity ramp elimination test on the target battery based on the initial battery data, and record the correction coefficient under the capacity ramp elimination test; A temperature module S1106, configured to adjust the temperature data, and record the gradient battery data of the target battery at different temperatures and the standard battery data of the target battery at the reference temperature; A model module S1108, configured to take the standard battery data as the standard condition and the gradient battery data as variables, fit a relationship model between the discharge capacity and the end-of-discharge temperature, and calculate the reference capacity of the target battery at the target compensation temperature based on the relationship model; An initial capacity adjustment module S1110, configured to use the initial end-of-discharge temperature and the standard discharge capacity as input data, and calculate the initial capacity correction data in combination with the relationship model and the correction coefficient.

[0050] In another embodiment, a lithium-ion battery capacity ramp correction system further includes: A discharge module, configured to place the target battery at the reference temperature and discharge it at a constant current at a first rate until the cut-off voltage; A charging module, configured to place the target battery at rest again and charge it at a constant current and constant voltage at a second rate until the cut-off current; A cycling module is configured to cycle the discharging and charging process a number of times, record the cycling discharge capacity in each discharging and charging cycle, compare the cycling discharge capacity with the initial discharge capacity, and calculate a correction factor.

[0051] In another embodiment, a lithium-ion battery capacity ramp correction system further includes: A calculation module is configured to calculate the average value of several groups of the target batteries when calculating the initial battery data, gradient battery data, and standard battery data.

[0052] Those skilled in the art can clearly understand that the technical solutions of the embodiments of the present application can be implemented by means of software and / or hardware. The "units" and "modules" in this specification refer to software and / or hardware that can independently complete or cooperate with other components to complete specific functions, where the hardware can be, for example, a Field-Programmable Gate Array (FPGA), an Integrated Circuit (IC), etc.

[0053] Each processing unit and / or module of the embodiments of the present application can be implemented by an analog circuit that implements the functions described in the embodiments of the present application, or can be implemented by software that executes the functions described in the embodiments of the present application.

[0054] See Figure 12 , which shows a schematic structural diagram of an electronic device related to the embodiments of the present application. This electronic device can be used to implement Figure 1 the method in the shown embodiments. As Figure 12 shown, the electronic device 1200 may include: at least one processor 1201, at least one network interface 1204, a user interface 1203, a memory 1205, and at least one communication bus 1202.

[0055] Among them, the communication bus 1202 is used to realize the connection and communication between these components.

[0056] Among them, the user interface 1203 may include a display screen (Display), a camera (Camera). Optionally, the user interface 1203 may further include a standard wired interface and a wireless interface.

[0057] Among them, the network interface 1204 may optionally include a standard wired interface and a wireless interface (such as a WI-FI interface).

[0058] Among them, the processor 1201 may include one or more processing cores. The processor 1201 connects various parts within the entire electronic device 1200 through various interfaces and lines. By running or executing instructions, programs, code sets, or instruction sets stored in the memory 1205, and by calling the data stored in the memory 1205, it performs various functions of the electronic device 1200 and processes data. Optionally, the processor 1201 may be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), or programmable logic array (PLA). The processor 1201 may integrate a combination of one or several of a central processing unit (CPU), a graphics processing unit (GPU), and a modem, etc. Among them, the CPU mainly processes the operating system, user interface, application programs, etc.; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communication. It can be understood that the above-mentioned modem may not be integrated into the processor 1201 and may be implemented separately by a single chip.

[0059] Among them, the memory 1205 may include random access memory (RAM) and may also include read-only memory. Optionally, the memory 1205 includes a non-transitory computer-readable storage medium. The memory 1205 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 1205 may include a program storage area and a data storage area. Among them, the program storage area may store instructions for implementing the operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store the data involved in the above-mentioned various method embodiments. Optionally, the memory 1205 may further be at least one storage device located far from the aforementioned processor 1201. As Figure 12 shown, the memory 1205, as a computer storage medium, may include an operating system, a network communication module, a user interface module, and program instructions.

[0060] In Figure 12In the electronic device 1200 shown, the user interface 1203 is mainly used to provide an interface for the user to input and obtain the data input by the user. The processor 1201 can be used to call the interactive application program generated based on images stored in the memory 1205 and specifically perform the following operations: record the initial battery data during the first charge and discharge process of the target battery, where the battery data includes the end-of-discharge temperature and the discharge capacity; based on the initial battery data, perform a capacity ramp elimination test on the target battery and record the correction factor under the capacity ramp elimination test; adjust the temperature data, record the gradient battery data of the target battery at different temperatures, and the standard battery data of the target battery at the reference temperature; using the standard battery data as the standard condition and the gradient battery data as variables, fit the relationship model between the discharge capacity and the end-of-discharge temperature, and calculate the benchmark capacity of the target battery at the target compensation temperature based on the relationship model; using the initial end-of-discharge temperature and the standard discharge capacity as input data, combine the relationship model and the correction factor to calculate the initial capacity correction data.

[0061] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of the above method are implemented. Among them, the computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0062] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0063] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] In several embodiments provided in the present application, it should be understood that the disclosed device 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 coupling or direct coupling or communication connection between each other can be through some service interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical or other form.

[0065] 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 they can be 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 this embodiment.

[0066] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0067] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. And the aforementioned memory includes: USB flash drive, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk or optical disc and other media that can store program codes.

[0068] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program. This program can be stored in a computer-readable memory. The memory can include: flash drive, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disc, etc.

[0069] The foregoing describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the acts or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily require the particular order shown or sequential order to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for correcting the capacity ramp of a lithium-ion battery, the method comprising: Recording the initial battery data during the first charge and discharge of the target battery, the battery data including the end-of-discharge temperature and the discharge capacity; Based on the initial battery data, performing a capacity ramp elimination test on the target battery and recording the correction factor under the capacity ramp elimination test; Adjusting the temperature data, recording the gradient battery data of the target battery at different temperatures, and the standard battery data of the target battery at the reference temperature data; Using the standard battery data as the standard condition and the gradient battery data as the variable, fitting a relationship model between the discharge capacity and the end-of-discharge temperature, and calculating the benchmark capacity of the target battery at the target compensation temperature based on the relationship model; Using the initial end-of-discharge temperature and the standard discharge capacity as input data, combining the relationship model and the correction factor to calculate the initial capacity correction data.

2. The method according to claim 1, characterized in that The capacity ramp elimination test includes: Placing the target battery statically at the reference temperature and discharging it at a constant current at the first rate until the cut-off voltage; Placing the target battery static again and charging it at a constant current and constant voltage at the second rate until the cut-off current; Repeating the charge and discharge process several times and recording the cyclic discharge capacity in each charge and discharge cycle, comparing the cyclic discharge capacity with the initial discharge capacity, and calculating the correction factor.

3. The method according to claim 2, wherein The step of using the standard battery data as the standard condition and the gradient battery data as the variable to fit a relationship model between the discharge capacity and the end-of-discharge temperature includes: Based on a preset functional relationship, comparing the variable with the standard condition in sequence and quantitatively calculating the constants in the functional relationship, the functional relationship being: where C is the discharge capacity in the gradient battery data, is the discharge capacity in the standard battery data, x is the discharge end temperature in the gradient battery data, and a, b, and c are constants.

4. The method according to claim 3, characterized in that, The step of using the initial end-of-discharge temperature and the standard discharge capacity as input data, combining the relationship model and the correction factor to calculate the initial capacity correction data includes: Adjusting the functional relationship to a second relationship associated with the capacity ramp elimination experiment, the second relationship being: Where n is the number of cycles in the capacity ramp elimination test and t is the correction factor.

5. The method according to any one of claims 1 to 4, characterized in that The method further includes: When calculating the initial battery data, the gradient battery data, and the standard battery data, calculating the average value of several groups of the target battery.

6. A lithium-ion battery capacity ramp-up correction system, characterized in that, The system includes; A recording module for recording the initial battery data during the first charge and discharge of the target battery, the battery data including the end-of-discharge temperature and the discharge capacity; An experiment module for performing a capacity ramp elimination test on the target battery based on the initial battery data and recording the correction factor under the capacity ramp elimination test; A temperature module for adjusting the temperature data, recording the gradient battery data of the target battery at different temperatures, and the standard battery data of the target battery at the reference temperature data; A model module for using the standard battery data as the standard condition and the gradient battery data as the variable to fit a relationship model between the discharge capacity and the end-of-discharge temperature, and calculating the benchmark capacity of the target battery at the target compensation temperature based on the relationship model; An initial capacity adjustment module, configured to use the initial discharge end temperature and the standard discharge capacity as input data, and in combination with the relationship model and the correction coefficient, calculate the initial capacity correction data.

7. The system according to claim 6, wherein The system further includes: A discharge module, configured to place the target battery at a reference temperature and perform constant current discharge at a first rate until the cut-off voltage is reached. A charging module, configured to place the target battery again and perform constant current and constant voltage charging at a second rate until the cut-off current is reached. A cycling module, configured to cycle the discharge and charge processes a certain number of times, record the cyclic discharge capacity in each discharge and charge cycle, compare the cyclic discharge capacity with the initial discharge capacity, and calculate the correction coefficient.

8. The system according to claim 6 or 7, characterized in that The system further includes: A calculation module, configured to calculate the average value of several groups of the target batteries when calculating the initial battery data, the gradient battery data, and the standard battery data.

9. An electronic device, including a processor and a memory; The processor is connected to the memory; The memory is configured to store executable program code; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to execute the method according to any one of claims 1-5.

10. A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method according to any one of claims 1-5 is implemented.

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