Lithium battery DCR correction method and system, storage medium and computing device

Abstract

The invention relates to the field of lithium ion battery manufacturing, and discloses a lithium battery DCR correction method and system, a storage medium and computing equipment, and the method comprises the steps: setting a DCR test step under SOC with a preset percentage added in a production line capacity grading step; according to a set test step, carrying out capacity grading test on the capacity grading battery cell upper cabinet according to the capacity grading step to obtain the battery cell DCR, and extracting the DCR data of the whole batch of lithium batteries and the temperature data of the corresponding single batteries; performing data statistics and equation fitting on the extracted DCR and the corresponding single battery temperature data to obtain a corresponding relation equation between the DCR and the temperature of the battery; and inputting the fitting equation into a battery cell database system, so that the database system automatically corrects the DCR of each battery at the set temperature, and performing DCR selection on the basis. According to the method, the DCR of the battery cell is tested on a capacity grading cabinet point under the condition of 50% SOC, and the real DCR of the lithium battery is determined through a temperature compensation method.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion battery manufacturing, and in particular to a method, system, storage medium and computing device for correcting DCR of a lithium battery. Background Art

[0002] Lithium-ion batteries have become the mainstream choice for automotive power batteries due to their high energy density, long cycle life, and no memory effect. As battery manufacturing technology becomes more and more mature, competition among manufacturers is becoming increasingly fierce.

[0003] The preparation process of lithium batteries is complicated, including slurry mixing, coating, roller separation, winding, assembly, baking, liquid injection, formation, capacity separation, K value and DCR. So many processes directly lead to the consistency problem of battery cells. DCR is an important assessment and sorting indicator for battery cell consistency. However, the current production lines all place the DCR test after measuring the K value. At this time, the SOC of the battery cell is at a lower state (5% SOC or 17% SOC), but at 5% SOC, SOC fluctuations have a greater impact on the DCR of the battery cell. At the same time, strict requirements are also required for the environmental control of DCR testing. The size of DCR is also strongly related to temperature. This will inevitably lead to the fact that the true DCR of the battery cannot be known. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method, system, storage medium and computing device for DCR correction of lithium batteries, which can reduce DCR testing equipment in production line planning, test the DCR of battery cells under 50% SOC conditions at the capacity distribution cabinet point, and determine the true DCR of the lithium battery by temperature compensation method.

[0005] To achieve the above purpose, in the first aspect, the technical solution adopted by the present invention is: a method for correcting the DCR of a lithium battery, which includes: setting a DCR test step under SOC with a preset percentage in the production line capacity division step; according to the set test step, the capacity division test is performed on the capacity division cabinet according to the capacity division step to obtain the DCR of the battery cell, and the DCR data of the entire batch of lithium batteries and the corresponding single battery temperature data are extracted; the extracted DCR and the corresponding single battery temperature data are statistically analyzed and equation fitting is performed to obtain the corresponding relationship equation between the battery DCR and the temperature; the fitting equation is input into the battery cell database system so that the database system automatically corrects the DCR of each battery at the set temperature, and selects the DCR based on this. The present invention tests the battery cell DCR under the condition of setting a percentage SOC at the capacity division cabinet point, and determines the true DCR of the lithium battery by the temperature compensation method, which effectively eliminates the influence of uneven temperature distribution and SOC fluctuation on the DCR of the lithium battery in the capacity division workshop.

[0006] Further, the preset percentage of SOC is: 50% SOC; the SOC of the DCR test is performed under the condition of 50% SOC.

[0007] Furthermore, the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data are extracted, including:

[0008] The temperature data of the corresponding single battery is collected by the temperature sensor installed on the top of each battery core aluminum shell;

[0009] Extract the valid DCR data and the corresponding temperature data of the same batch completed within 24 hours.

[0010] Furthermore, the effective DCR data is calculated by collecting voltage and current data through the database system, and the single cell temperature data is the temperature data corresponding to the first second of the DCR test of the battery cell.

[0011] Furthermore, the corresponding equation of battery DCR and temperature is a linear equation:

[0012] R=C+K×T,

[0013] Where R is the DCR value, C and K are fixed values, and T is the temperature value.

[0014] Furthermore, automatically correcting the DCR of each battery at a set temperature includes: determining the relationship between the battery DCR and the temperature according to a corresponding relationship equation between the battery DCR and the temperature, and correcting the DCR of each battery at a specific temperature according to the relationship.

[0015] Furthermore, the correction of the DCR of each battery at a set temperature is:

[0016] R 修正 =R 原 +K(T 设 -T 原 )

[0017] In the formula, R 修正 is the corrected value of DCR, R 原 is the original DCR value, T 设 is the set temperature value, T 原 is the original temperature value.

[0018] In the second aspect, the technical solution adopted by the present invention is: a lithium battery DCR correction system, which includes: a condition addition module, which sets a DCR test step under SOC with a preset percentage added in the production line capacity division step; a DCR and temperature data acquisition module, which performs capacity division test on the capacity division cell cabinet according to the set test step to obtain the cell DCR, and extracts the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data; a fitting module, which performs data statistics and equation fitting on the extracted DCR and the corresponding single cell temperature data to obtain a corresponding relationship equation between the battery DCR and the temperature; a correction module, which inputs the fitting equation into the cell database system, so that the database system automatically corrects the DCR of each battery at the set temperature, and selects the DCR based on this.

[0019] In a third aspect, the technical solution adopted by the present invention is: a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, and when the instructions are executed by a computing device, the computing device executes any one of the above methods.

[0020] A computing device comprises: one or more processors, a memory and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any of the above methods.

[0021] The present invention adopts the above technical solution, which has the following advantages:

[0022] The present invention adopts a capacity division cabinet point, adds a DCR test step under 50% SOC in the capacity division step, fits and establishes a DCR and temperature relationship equation, automatically corrects and sorts the DCR at a set temperature through a database system, effectively eliminates the influence of uneven temperature distribution and SOC fluctuation on the DCR of lithium batteries in the capacity division workshop, improves the sorting accuracy, and reduces the DCR test equipment at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a flow chart of a method for correcting DCR of a lithium battery in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to solve the problem that the real DCR of the battery cannot be known in the prior art, the present invention provides a method, system, storage medium and computing device for DCR correction of lithium batteries. The use of capacity cabinet point test can reduce DCR testing equipment and solve the technical problem that the real DCR of the battery cannot be known. The present invention includes: adding a 50% SOC DCR test step in the capacity division step of the production line; the capacity division cell cabinet is subjected to capacity division test to obtain the DCR of the cell according to the capacity division step; the DCR data of the whole batch of lithium batteries and the corresponding single cell temperature data are extracted; the extracted DCR and the corresponding single cell temperature data are statistically analyzed and equation fitting is performed to obtain the corresponding relationship equation between the battery DCR and the temperature; the fitting equation is programmed and input into the cell database system; the system automatically corrects the DCR of each battery at the set temperature and selects the DCR based on this. The present invention automatically corrects the DCR of each lithium battery by equation fitting, and the equation formula is input into the cell database system, so as to improve the sorting accuracy for the subsequent lithium battery sorting and reduce the separate DCR equipment for the production line construction.

[0025] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] In one embodiment of the present invention, a method for DCR correction of a lithium battery is provided. In this embodiment, Figure 1 As shown, the method comprises the following steps:

[0028] 1) In the production line capacity division step, set a DCR test step under SOC with a preset percentage increase;

[0029] 2) According to the set test steps, the DCR of the cells is tested in the cell cabinet according to the capacity separation steps, and the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data are extracted;

[0030] 3) Perform data statistics on the extracted DCR and the corresponding single cell temperature data and perform equation fitting to obtain the corresponding relationship equation between the battery DCR and temperature;

[0031] 4) Input the fitting equation into the battery cell database system so that the database system can automatically correct the DCR of each battery at the set temperature and use it as a basis for DCR selection.

[0032] In the above step 1), the preset percentage of SOC is: 50% SOC; the SOC of the DCR test is carried out under the condition of 50% SOC, under which the DCR fluctuates little with the SOC. Among them, the DCR test step is set during the discharge process of the battery cell.

[0033] Specifically, the cell test process step is compiled in the computer control software interface of the capacity division cabinet. The cell is first fully charged and then left to stand for 30 minutes. Then, the cell SOC is adjusted to 50% SOC and left to stand for 30 minutes. The DCR test process step is set, and 1C discharge is performed for 10 seconds. After standing for 5 minutes, the cell continues to undergo capacity division test.

[0034] Since the SOC of the DCR test is under 50% SOC conditions, the DCR fluctuation of the battery cell under the measured SOC is relatively small as the SOC fluctuates, reducing the impact of SOC fluctuations on DCR.

[0035] In this embodiment, a 50% SOC DCR test step is added to the production line capacity division step, and the DCR test step can be appropriately adjusted according to the current carrying capacity of the production line capacity division equipment.

[0036] In the above step 2), extracting the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data includes the following steps:

[0037] 2.1) The temperature data of the corresponding single battery is collected by the temperature sensor installed on the top of each battery core aluminum shell;

[0038] Specifically, the battery cells to be divided are bound by scanning the code, and the materials are automatically put into the capacity division cabinet for capacity division test according to the capacity division process set in step 1). At the same time, there is a temperature sensor on the top of the aluminum shell of each battery cell for temperature detection.

[0039] 2.2) Extract the valid DCR data and the corresponding temperature data of the same batch completed within 24 hours.

[0040] In this embodiment, the effective DCR data is calculated by collecting voltage and current data through the database system, and the temperature data of the single battery is the temperature data corresponding to the first second of the DCR test of the battery cell. Among them, the DCR test cabinet point is the production line capacity division equipment.

[0041] In this embodiment, the overall range of the extracted temperature data is 20°C to 45°C.

[0042] In the above step 3), the corresponding relationship equation between battery DCR and temperature is a linear equation:

[0043] R=C+K×T,

[0044] Where R is the DCR value, C and K are fixed values, and T is the temperature value.

[0045] In this embodiment, a linear fitting equation is used, but other forms of fitting equations are not excluded.

[0046] In the above step 4), the DCR of each battery at the set temperature is automatically corrected, specifically: the relationship between the battery DCR and the temperature is determined according to the corresponding relationship equation between the battery DCR and the temperature, and the DCR of each battery at the specific temperature is corrected according to the relationship.

[0047] In this embodiment, the correction of the DCR of each battery at a set temperature is:

[0048] R 修正 =R 原 +K(T 设 -T 原 )

[0049] In the formula, R 修正 is the corrected value of DCR, R 原 is the original DCR value, T 设 is the set temperature value, T 原 is the original temperature value.

[0050] Enter the above formula into the database system to achieve the battery cell R 修正 Automatically generated.

[0051] In this embodiment, T 设 The temperature is selected between 20-45°C, preferably 25°C.

[0052] In one embodiment of the present invention, a lithium battery DCR correction system is provided, comprising:

[0053] Conditional addition module, set to add a preset percentage of SOC DCR test step in the production line capacity division step;

[0054] The DCR and temperature data acquisition module performs capacity tests on the capacity-based battery cabinet according to the set test steps to obtain the DCR of the battery cells, and extracts the DCR data of the entire batch of lithium batteries and the corresponding single battery temperature data;

[0055] The fitting module performs data statistics and equation fitting on the extracted DCR and the corresponding single cell temperature data to obtain the corresponding relationship equation between the battery DCR and the temperature;

[0056] The correction module inputs the fitting equation into the battery cell database system so that the database system automatically corrects the DCR of each battery at the set temperature and selects the DCR based on this.

[0057] In the above embodiment, the preset percentage of SOC is: 50% SOC; the SOC of the DCR test is performed under the condition of 50% SOC.

[0058] In the above embodiment, extracting the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data includes:

[0059] The temperature data of the corresponding single battery is collected by the temperature sensor installed on the top of each battery core aluminum shell;

[0060] Extract the valid DCR data and the corresponding temperature data of the same batch completed within 24 hours.

[0061] In this embodiment, the effective DCR data is calculated by collecting voltage and current data through the database system, and the single cell temperature data is the temperature data corresponding to the first second of the DCR test of the battery cell.

[0062] In the above embodiment, the corresponding relationship equation between the battery DCR and the temperature is a linear equation:

[0063] R=C+K×T,

[0064] Where R is the DCR value, C and K are fixed values, and T is the temperature value.

[0065] In the above embodiment, automatically correcting the DCR of each battery at a set temperature includes: determining the relationship between the battery DCR and the temperature according to the corresponding relationship equation between the battery DCR and the temperature, and correcting the DCR of each battery at a specific temperature according to the relationship.

[0066] Among them, the correction of DCR of each battery at the set temperature is:

[0067] R 修正 =R 原 +K(T 设 -T 原 )

[0068] In the formula, R 修正 is the corrected value of DCR, R 原 is the original DCR value, T 设 is the set temperature value, T 原is the original temperature value.

[0069] The system provided in this embodiment is used to execute the above-mentioned method embodiments. Please refer to the above-mentioned embodiments for specific processes and detailed contents, which will not be repeated here.

[0070] In summary, the present invention tests the DCR of the battery cell under the condition of 50% SOC at the capacity distribution cabinet point, determines the real DCR of the lithium battery by the temperature compensation method, improves the accuracy of DCR sorting, and ensures the consistency of the battery cell.

[0071] A computing device provided in one embodiment of the present invention may be a terminal, which may include: a processor, a communications interface, a memory, a display screen, and an input device. The processor, the communications interface, and the memory communicate with each other through a communication bus. The processor is used to provide computing and control capabilities. The memory includes a non-volatile storage medium and an internal memory, wherein the non-volatile storage medium stores an operating system and a computer program, and the computer program is executed by the processor to implement the methods in the above embodiments; the internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through WIFI, a management network, NFC (near field communication) or other technologies. The display screen may be a liquid crystal display screen or an electronic ink display screen, and the input device may be a touch layer covered on the display screen, or a key, trackball or touchpad provided on the housing of the computing device, or an external keyboard, touchpad or mouse, etc. The processor may call the logic instructions in the memory.

[0072] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0073] In one embodiment of the present invention, a computer program product is provided, wherein the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the methods provided by the above-mentioned method embodiments.

[0074] In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided, wherein the non-transitory computer-readable storage medium stores server instructions, and the computer instructions enable a computer to execute the methods provided in the above embodiments.

[0075] The above embodiment provides a computer-readable storage medium, whose implementation principle and technical effect are similar to those of the above method embodiment, and will not be repeated here.

[0076] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0077] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for correcting DCR of a lithium battery, characterized in that: include: In the production line capacity division step, set a DCR test step under SOC with a preset percentage increase; According to the set test steps, the DCR of the cells is tested in the cell cabinet according to the capacity separation steps, and the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data are extracted; The extracted DCR and the corresponding single cell temperature data are statistically analyzed and fitted with equations to obtain the corresponding relationship equation between battery DCR and temperature. The fitting equation is input into the battery cell database system so that the database system can automatically correct the DCR of each battery at the set temperature and use it as a basis for DCR selection.

2. The method for correcting DCR of a lithium battery as claimed in claim 1, characterized in that: The preset percentage of SOC is: 50% SOC; the SOC of the DCR test is performed under the condition of 50% SOC.

3. The method for DCR correction of a lithium battery as claimed in claim 1, characterized in that: Extract the DCR data of the entire batch of lithium batteries and the corresponding single cell temperature data, including: The temperature data of the corresponding single battery is collected by the temperature sensor installed on the top of each battery core aluminum shell; Extract the valid DCR data and the corresponding temperature data of the same batch completed within 24 hours.

4. The method for correcting DCR of a lithium battery as claimed in claim 3, characterized in that: The effective DCR data is calculated by collecting voltage and current data through the database system. The single cell temperature data is the temperature data corresponding to the first second of the DCR test of the battery cell.

5. The method for correcting DCR of a lithium battery as claimed in claim 1, characterized in that: The corresponding relationship equation between battery DCR and temperature is a linear equation: R=C+K×T, Where R is the DCR value, C and K are fixed values, and T is the temperature value.

6. The method for correcting DCR of a lithium battery as claimed in claim 1, characterized in that: Automatically correcting the DCR of each battery at a set temperature includes: determining the relationship between the battery DCR and the temperature according to a corresponding relationship equation between the battery DCR and the temperature, and correcting the DCR of each battery at a specific temperature according to the relationship.

7. The method for correcting DCR of a lithium battery as claimed in claim 6, characterized in that: The correction of DCR of each battery at a set temperature is: R 修正 =R 原 +K(T 设 -T 原 ) In the formula, R 修正 is the corrected value of DCR, R 原 is the original DCR value, T 设 is the set temperature value, T 原 is the original temperature value.

8. A lithium battery DCR correction system, characterized in that: include: Conditional addition module, set to add a preset percentage of SOC DCR test step in the production line capacity division step; The DCR and temperature data acquisition module performs capacity tests on the capacity-based battery cabinet according to the set test steps to obtain the DCR of the battery cells, and extracts the DCR data of the entire batch of lithium batteries and the corresponding single battery temperature data; The fitting module performs data statistics and equation fitting on the extracted DCR and the corresponding single cell temperature data to obtain the corresponding relationship equation between the battery DCR and the temperature; The correction module inputs the fitting equation into the battery cell database system so that the database system automatically corrects the DCR of each battery at the set temperature and selects the DCR based on this.

9. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform any one of the methods of claims 1 to 7.

10. A computing device, characterized in that: include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any one of the methods described in claims 1 to 7.

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