Lithium battery manufacturing method and manufacturing device

Abstract

The invention provides a lithium battery manufacturing method and a lithium battery manufacturing device. The lithium battery manufacturing method comprises the following steps: determining an environment cleanliness grade required by current production of a lithium battery; and selecting a diaphragm material with corresponding puncture-resistant strength according to the environmental cleanliness grade. By means of the scheme, the upper limit of the requirement for cleanliness in lithium battery production is improved, diaphragms with different characteristics can be matched according to different manufacturing environments, the cleanliness and dust control requirements of the lithium battery manufacturing environments are reduced, it is avoided that many dust removal devices are adopted, and the control complexity in the lithium battery manufacturing process is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery manufacturing, and in particular to a lithium battery manufacturing method and manufacturing device. BACKGROUND

[0002] The manufacturing process of a lithium ion battery involves various chemicals and precise processes, and has strict requirements for environmental cleanliness. Dust particles and other pollutants in the air can adversely affect the performance of the battery.

[0003] In related technologies, a filtration system is used to remove pollutants in the air, and a clean room is constructed to ensure the cleanliness of the manufacturing environment. However, the cleanliness level of a lithium battery clean room is usually required to reach ISO 7 (ten thousand level) or ISO 8 (hundred thousand level), and the filtration system designed for a cleanliness of ten thousand level (ISO 7) may need to set an air exchange frequency of 20-30 times / hour, which undoubtedly increases the control complexity of the battery manufacturing process and increases the cost and expense. SUMMARY

[0004] Embodiments of the present application provide a lithium battery manufacturing method and manufacturing device to solve the problem of complex control process of cleanliness in the lithium battery manufacturing process in related technologies.

[0005] To solve the above problems, the technical solutions provided by the present application are as follows:

[0006] In a first aspect, the present application provides a lithium battery manufacturing method, comprising: determining the required environmental cleanliness level for current lithium battery production; and selecting a corresponding puncture-resistant diaphragm material according to the environmental cleanliness level.

[0007] In an embodiment, the lithium battery manufacturing method further comprises: collecting real-time particle concentration data of the lithium battery production area, and dividing the environmental cleanliness level according to the particle concentration data according to a preset standard; and constructing a relationship database of the environmental cleanliness level and the diaphragm puncture strength according to the required environmental cleanliness level for lithium battery production.

[0008] In an embodiment, the real-time collection of the particle concentration data of the lithium battery production area and the division of the environmental cleanliness level according to the particle concentration data according to a preset standard comprises: collecting the number of particles of a specific particle size per unit volume in the lithium battery production area in real time, and dividing the environmental cleanliness level into multiple environmental cleanliness levels according to the number of particles.

[0009] In an embodiment, the construction of the relationship database of the environmental cleanliness level and the diaphragm puncture strength comprises: matching a diaphragm material with a higher puncture resistance according to an increase in the environmental cleanliness level value.

[0010] In an embodiment, the environmental cleanliness level comprises: ISO class 4, ISO Class 5, ISO Class 7, ISO Class 8 and ISO Class 9, corresponding to the puncture resistance of the separator material in turn ≥ 0.13 N / μm, ≥ 0.20 N / μm, ≥ 0.5 N / μm, ≥ 0.7 N / μm and ≥ 1.2 N / μm respectively.

[0011] In an embodiment, after selecting the separator material corresponding to the puncture resistance according to the environmental cleanliness level, the lithium battery manufacturing method comprises: adjusting the process parameters of the lithium battery production equipment according to the puncture resistance of the currently selected separator material, assembling the separator, the positive electrode sheet and the negative electrode sheet to form a roll core, and then performing welding, baking, liquid injection and activation processes to complete the assembly of the lithium battery.

[0012] In an embodiment, the lithium battery manufacturing method further comprises: analyzing historical environmental data to predict the change trend of the environmental cleanliness in the future production period; in the case of predicting that the environmental cleanliness has a downward trend, preloading a separator with higher puncture resistance and triggering a pre-command to adjust the process parameters of the lithium battery production equipment.

[0013] In an embodiment, the lithium battery manufacturing method further comprises: performing quality detection on the assembled lithium battery, and in the case of detecting that the separator is punctured or short-circuited due to particulate pollution, determining the target process in which the puncture event occurs according to the production time stamp of the abnormal battery; tracing the historical environmental cleanliness level of the target process at the time period when the puncture event occurs based on the production time stamp; counting the puncture rate of the separator under the historical environmental cleanliness level in the historical database; in the case that the puncture rate reaches a preset threshold, improving the puncture resistance of the separator corresponding to the environmental cleanliness level; correcting the relationship database between the environmental cleanliness and the puncture resistance of the separator based on the improved puncture resistance of the separator; and reloading the separator material adapted to the current environmental cleanliness according to the corrected relationship database.

[0014] In an embodiment, the lithium battery manufacturing method further comprises: in a parallel production scenario, dividing the priority of the separator material according to the cleanliness requirement difference of each process; and in the case that the cleanliness requirements of different processes conflict, adjusting the separator supply distribution strategy according to the order of electrode preparation, cell assembly and formation detection.

[0015] In a second aspect, the application provides a lithium battery manufacturing device, comprising: a control module configured to determine the environmental cleanliness level required for the current production of lithium batteries; and a supply module configured to select a separator material corresponding to the puncture resistance according to the environmental cleanliness level.

[0016] In an embodiment, the lithium battery manufacturing device further comprises a monitoring module configured to collect particle concentration data of a lithium battery production area in real time, and divide an environmental cleanliness level according to the particle concentration data according to a preset standard; the control module is further configured to construct a relational database of the environmental cleanliness level and the puncture strength of the diaphragm according to the environmental cleanliness level required by the lithium battery production.

[0017] In an embodiment, the lithium battery manufacturing device further comprises an execution module configured to assemble the diaphragm, the positive electrode sheet and the negative electrode sheet to form a roll core, and then perform welding, baking, liquid injection and activation processes to complete the assembly of the lithium battery; the control module is further configured to adjust the process parameters of the execution module according to the puncture resistance of the diaphragm material currently selected by the feeding module.

[0018] The embodiments of the present application provide a lithium battery manufacturing method and a manufacturing device. The lithium battery manufacturing method comprises: determining an environmental cleanliness level required by a current production process of a lithium battery; and selecting a diaphragm material with a corresponding puncture resistance according to the environmental cleanliness level. Through the scheme, the present application improves the upper limit of the cleanliness requirement in the production of the lithium battery, and can match diaphragms with different characteristics according to different manufacturing environments, reduces the cleanliness and dust control requirements of the manufacturing environment of the lithium battery, avoids the use of more dust removal equipment, and reduces the control complexity in the manufacturing process of the lithium battery. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] FIG. 1 is a flowchart of a lithium battery manufacturing method according to an embodiment of the present application; Figure 1 FIG. 2 is a relationship curve between the puncture resistance of a diaphragm and the environmental cleanliness ISO according to an embodiment of the present application; FIG. 3 is a relationship diagram between a filter and a filtering frequency according to an embodiment of the present application;

[0021] FIG. 4 is a relationship diagram between an environmental cleanliness level and a dust removal wind speed according to an embodiment of the present application; Figure 2 FIG. 5 is a module schematic diagram of a lithium battery manufacturing device according to an embodiment of the present application.

[0022] FIG. 6 is a relationship diagram between a filter and a filtering frequency according to an embodiment of the present application; Figure 3 FIG. 7 is a relationship diagram between an environmental cleanliness level and a dust removal wind speed according to an embodiment of the present application;

[0023] FIG. 8 is a module schematic diagram of a lithium battery manufacturing device according to an embodiment of the present application. Figure 4 FIG. 9 is a relationship diagram between an environmental cleanliness level and a dust removal wind speed according to an embodiment of the present application.

[0024] FIG. 10 is a module schematic diagram of a lithium battery manufacturing device according to an embodiment of the present application. Figure 5 FIG. 11 is a module schematic diagram of a lithium battery manufacturing device according to an embodiment of the present application.

[0025] The reference signs in the drawings indicate:

[0026] 100, lithium battery manufacturing device; 110, monitoring module; 120, control module; 130, feeding module; 140, execution module. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] It will be understood that the terms "include" and / or "contain" used herein specify the presence of a feature or component, but do not exclude the presence or addition of one or more other features or components.

[0029] The production process of lithium ion batteries involves various chemicals and precise processes, and has strict requirements on environmental cleanliness. Dust particles, fine particles and other pollutants in the air can adversely affect battery performance. In the related art, a lithium battery plant uses a filter combination of one or more of a primary filter, a medium filter, a high-efficiency particulate air (HEPA) filter or an ultra low penetration air filter (ULPA) to effectively remove particulate matter with a particle size of 0.3 μm and above in the air, ensuring that the concentration of airborne particles meets the standard. Based on differential pressure monitoring, cleanliness testing and actual environment, the primary filter needs to be replaced every 1 to 3 months, the medium filter needs to be replaced every 2 to 6 months, and the high-efficiency filter needs to be replaced every 6 to 12 months, which undoubtedly increases the cost of battery manufacturing.

[0030] In key processes such as electrode slurry preparation and liquid injection, it may be necessary to achieve ISO 5 level of environmental cleanliness in the production environment, which requires the use of high-efficiency filters and control of cross-sectional air speed (vertical laminar flow ≥ 0.25 m / s, horizontal laminar flow ≥ 0.35 m / s) to achieve, which increases the control complexity and difficulty in the production process of lithium batteries, and also increases the manufacturing cost. In addition to the space gas cleaning of the large environment, the cleaning and dust collection of the dust production area in the local equipment also require complex control, such as high-risk dust production processes such as laser die cutting, dust collection pipelines need to meet different wind speed gradients, the wind speed in the laser dust removal suction pipe requires more than 23 m / s, and the wind speed in other interface pipes requires more than or equal to 15 m / s of end dust removal speed. Similarly, this also increases the manufacturing cost of lithium batteries.

[0031] ReferenceFigure 1 According to the first aspect of the present application, the present application provides a lithium battery manufacturing method, comprising:

[0032] Step S10: Real-time collection of particle concentration data in the lithium battery production area, and division of the environmental cleanliness level according to the particle concentration data according to a preset standard;

[0033] Specifically, this step includes: real-time collection of the number of particles of a specific particle size per unit volume in the lithium battery production area, and division of the environmental cleanliness into a plurality of environmental cleanliness levels (ISO Class level) according to the number of particles. The sensitivity of each process of lithium battery production to particle pollution and the dust production amount are significantly different, and even in the same process, the environmental cleanliness may change in real time due to equipment operation, personnel activities, or air conditioning system fluctuations, etc. Therefore, the number of particles of a specific particle size per unit volume in the lithium battery production area in each different production process needs to be collected, so that the influence of each process on the environmental cleanliness can be grasped while grading the environmental cleanliness according to the number of particles, and the optimization of material cost, energy consumption and production efficiency can be realized under the premise of controllable quality risk.

[0034] It should be noted that the environmental cleanliness level is the level of air cleanliness in a clean room (area) and related controlled environment according to the only index of suspended particle concentration in the international standard ISO14644, and only considers the particle group with cumulative distribution of particle size limit (lower limit) in the range of 0.1um-5.0um. According to the particle size, it can be divided into conventional particles (0.1um-5.0um), ultrafine particles (<0.1um) and macro-particles (>5.0um). That is, the environmental cleanliness level represents the number of particles of a specific particle size per unit volume, so the smaller the number in the level name of ISOClass4 to ISOClass9, the higher the cleanliness. Referring to Table 1, the maximum concentration limit of particles of a specific particle size corresponding to different environmental cleanliness levels.

[0035] Table 1 Maximum concentration limit of particles of a specific particle size corresponding to different environmental cleanliness levels

[0036]

[0037] In some embodiments of the present application, the collection of the number of particles can be realized by a dust particle counter. It can be understood that the particles referred to in the embodiments of the present application refer to all dust and other particulate pollutants suspended in the air, not just one kind of pollutant.

[0038] Step S20: According to the environmental cleanliness level required for lithium battery production, a relational database of environmental cleanliness level and membrane puncture strength is constructed;

[0039] Specifically, in the process of constructing the relational database, referring to Figure 2 As shown in the figure, with the increase of the environmental cleanliness level value, a higher puncture-resistant membrane material needs to be matched, that is, the more the number of particles suspended in the air, the higher the puncture-resistant strength of the membrane material needs to be. Among them, according to the environmental cleanliness of assembly and welding, the required puncture-resistant strength of the membrane corresponding to different environmental cleanliness is shown in Table 2. According to different puncture-resistant strength, the application also provides some specific embodiments.

[0040] Table 2 Environmental cleanliness corresponding to membrane puncture-resistant strength table

[0041]

[0042] It can be seen that the environmental cleanliness level at least includes: ISO class4, ISO Class5, ISO Class7, ISO Class8 and ISO Class9, and the corresponding puncture-resistant strength of the membrane material is ≥0.13N / μm, ≥0.20N / μm, ≥0.5N / μm, ≥0.7N / μm and ≥1.2N / μm, respectively. Among them, in the case of environmental cleanliness level Class4, the membrane material can be polypropylene (PP) polymer formed by dry single-drawing process; in the case of environmental cleanliness level Class5, the membrane can be polyethylene (PE) membrane manufactured by wet process; in the case of environmental cleanliness level Class7, the membrane material can be a composite material of metallocene polyethylene (m-PE) and ceramic; in the case of environmental cleanliness level Class8, the membrane material can be a composite material of metallocene polyethylene (m-PE), polyethylene terephthalate (PET) and ceramic coating; in the case of environmental cleanliness level Class9, the membrane material can be polyimide (PI).

[0043] In addition, it can also be seen that between part of the environmental cleanliness, the selection of the membrane is increased, for example, when the environmental cleanliness level is between Class4-5, the membrane can be a three-layer composite membrane of polypropylene (PP)-polyethylene (PE)-polypropylene (PP); when the environmental cleanliness level is between Class8-9, the membrane material can be a high molecular polymer of polyethylene terephthalate (PET).

[0044] Step S30: Determine the environmental cleanliness level required for current lithium battery production;

[0045] Optionally, in some embodiments of the present application, the number of particles in the area corresponding to each production process of the lithium battery can also be counted by the dust particle counter, so as to obtain the environmental cleanliness level of the area corresponding to each production process, and the most stringent environmental cleanliness level among them is taken as the environmental cleanliness level required for the current production.

[0046] Step S40: according to the environmental cleanliness level, the separator material corresponding to the puncture strength is selected.

[0047] Specifically, after determining the environmental cleanliness level required for the current production, the database of the relationship between the environmental cleanliness level and the puncture strength of the separator is called, so as to determine the required separator material.

[0048] Optionally, in some embodiments of the present application, an automatic feeding system can be used, and a double-station or multi-station feeding can be used at the feeding end of the lithium battery production. Different feeding stations are placed with different separator materials, and when the required separator material is determined, the automatic feeding mode can be used to quickly replace the separator material.

[0049] Step S50: according to the puncture strength of the currently selected separator material, the process parameters of the lithium battery production equipment are adjusted, the separator, the positive electrode sheet and the negative electrode sheet are assembled to form a roll core, and then the welding, baking, liquid injection and activation processes are performed to complete the assembly of the lithium battery.

[0050] Specifically, in this step, since the winding and welding processes will have certain influence on the puncture strength of the separator, the process parameters of the lithium battery production equipment to be adjusted include at least one of the winding tension of the separator in the winding process and the welding energy density in the welding process.

[0051] Optionally, in some embodiments of the present application, the lithium battery manufacturing method of the present application can further include: analyzing historical environmental data, predicting the change trend of the environmental cleanliness in the future production period, and in the case that it is predicted that the environmental cleanliness has a downward trend, preloading a separator with higher puncture strength and triggering a pre-command for adjusting the process parameters of the lithium battery production equipment. It should be noted that when the relevant control system has selected the separator material according to the current environmental cleanliness, but the actual separator material has not been put into production, in the case that the system also predicts that the environmental cleanliness will have a downward trend, it is necessary to determine whether the currently selected separator material meets the future cleanliness requirement. If yes, there is no need to load a separator with higher puncture strength, and if not, a separator with higher puncture strength is loaded.

[0052] In this embodiment, by analyzing historical environmental data, the future period of cleanliness decline trend can be predicted in advance, and the high-strength diaphragm can be switched to actively before the pollution event actually occurs, and the corresponding process parameters can be adjusted to avoid batch defects caused by environmental mutations. Based on this embodiment, in some more specific embodiments of the present application, during the preloading stage of the diaphragm, material buffering can be performed through double-station feeding, and the diaphragm roll can be prepared for splicing within a preset time before the current diaphragm roll is used up, avoiding material loss caused by emergency roll change.

[0053] In the foregoing method, as in step 20, according to the actual use, the relational database may need to be updated and further divided, so that the diaphragm material can meet the process needs. Optionally, in some embodiments of the present application, the updating process of the relational database is as follows:

[0054] Step S21: Quality detection is performed on the assembled lithium battery, and in the case of detecting diaphragm breakdown or short circuit caused by particulate pollution, the target process of the breakdown event is determined according to the production time stamp of the abnormal battery;

[0055] Optionally, in some embodiments of the present application, the quality of the lithium battery can be detected by X-ray, which can realize real-time imaging without contact and damage, and intuitively present the internal defects of the battery. When diaphragm breakdown defects are found in the lithium battery, the time stamp of the abnormal battery is extracted through the manufacturing execution system (MES) and combined with the production management system to trace the production log to determine the specific process of the defect, i.e. the target process. Through this way, the problem process can be quickly locked, avoiding time-consuming full-process troubleshooting.

[0056] Step S22: Based on the production time stamp, the historical environmental cleanliness level of the target process during the breakdown event period is traced;

[0057] In this step, the production management system queries the environmental cleanliness level corresponding to the breakdown event period according to the target process, so as to determine the approximate particulate concentration data, assist in judging the particle type of pollution, and further determine the cause of pollution.

[0058] Step S23: Statistics the diaphragm breakdown rate in the historical database under the historical environmental cleanliness level;

[0059] It should be noted that even if the cause of the pollution is determined in the foregoing step S22, it cannot be completely determined whether the pollution is an occasional incident or a normal event caused by a device problem, and therefore, the membrane rupture rate under the historical environmental cleanliness level in the historical database needs to be counted. For example, the total production of the battery in the past fixed period is M, and the number of abnormal batteries detected is N, and the membrane rupture rate is N / M*100%.

[0060] When the membrane rupture rate under the target process at the historical environmental cleanliness level is counted, the membrane rupture rate is compared with the preset threshold value, and in the case where the membrane rupture rate reaches the preset threshold value, it can be basically judged that the cause of the rupture event is not an occasional event, and the production process needs to be adjusted accordingly.

[0061] Step S24: In the case where the membrane rupture rate reaches the preset threshold value, the membrane puncture strength corresponding to the environmental cleanliness level is improved;

[0062] In some embodiments of the present application, the cause of the membrane rupture rate reaching the preset threshold value may be a misjudgment of the environmental cleanliness caused by sensor drift, and in this case, the sensor needs to be calibrated.

[0063] In some embodiments of the present application, the initially set membrane puncture strength may not be suitable for the corresponding environmental cleanliness level, and then the membrane puncture strength corresponding to the environmental cleanliness level needs to be improved; and since the production environment of the lithium battery is in a dynamic change, with the production, the suspended particles in the air may increase, but the environmental cleanliness level is divided according to the number of particles, and in some orders of magnitude, the particles can already affect the battery production, but the environmental cleanliness level has not changed, and then the corresponding membrane set according to the environmental cleanliness level may not be suitable for the current environment, and therefore, the membrane puncture strength corresponding to the environmental cleanliness level needs to be improved.

[0064] After a period of adjustment, the upper limit value of the membrane puncture strength under different environmental cleanliness levels can be obtained, and in the subsequent production process, the membrane material is selected according to the upper limit value of the membrane puncture strength, which can avoid the interference of occasional abnormal data to a certain extent.

[0065] Step S25: Correcting the relationship database between the environmental cleanliness level and the membrane puncture strength based on the improved membrane puncture strength;

[0066] Correspondingly, in the case where it is judged that the membrane puncture strength corresponding to the environmental cleanliness level needs to be improved, the relationship database between the environmental cleanliness level and the membrane puncture strength is updated synchronously, and the revision log is recorded.

[0067] Step S26: reload the membrane material adapted to the current environment cleanliness according to the revised relational database.

[0068] The updating of the relational database through the feedback mechanism of steps S21-S26 can accurately and quickly locate the pollution process, and based on historical data analysis, the adaptability of the membrane material can be continuously improved, and the reliability and economy of the lithium battery manufacturing can be improved.

[0069] Optionally, in some embodiments of the present application, there can be multiple production processes in parallel in the production of lithium batteries, and in these parallel production scenarios, the lithium battery manufacturing method of the present application further comprises: dividing the priority of the membrane material according to the cleanliness requirement difference of each process, and adjusting the membrane supply distribution strategy according to the order of electrode preparation-cell assembly-formation detection in the case of conflict between the cleanliness requirements of different processes. It should be noted that in the parallel production process, the sensitivity of different processes to airborne particulate matter is not the same, and the priority needs to be divided according to the sensitivity of the process to the environmental cleanliness level and the economic value, for example, the electrode preparation process is most sensitive to particulate pollution, and needs to match high-strength membranes to ensure that the electrode interface is defect-free, while the formation detection process has the highest tolerance to particulate pollution, so relatively low-strength membranes can be used, and the cell assembly process has a tolerance to particulate pollution between electrode preparation and formation detection, so membranes with a puncture strength between the two required membranes can be used. Through this scheme, the material can be distributed according to the demand, the abuse of high-strength membranes is reduced, the production cost is reduced, the quality of the core process is preferentially guaranteed, defects in the battery are avoided, and both economy and reliability are achieved.

[0070] In the related art, the required filter type and filtering times corresponding to different environmental cleanliness levels are shown in Figure 3 , wherein the higher the required environmental cleanliness level, the more filter combinations used, and the more filtering times required. Similarly, the required dust removal wind speed controlled by different environmental cleanliness levels is shown in Figure 4 , the higher the required environmental cleanliness level, the higher the dust removal wind speed to be controlled. Compared with the related art, the present application can dynamically switch the type of membrane used according to the requirement of environmental cleanliness level, greatly reducing the control complexity of the lithium battery production process, and greatly reducing the manufacturing cost of lithium battery production due to the reduction of the use of filters and dust removal equipment.

[0071] Referring to Figure 5 , according to the second aspect of the present application, a lithium battery manufacturing device 100 is provided for implementing the lithium battery manufacturing method of the preceding embodiments, which has all the beneficial effects of the lithium battery manufacturing method of the preceding embodiments, which will not be repeated here.

[0072] The lithium battery manufacturing device 100 comprises a monitoring module 110, a control module 120, a feeding module 130 and an execution module 140.

[0073] Specifically, the monitoring module 110 is configured to collect the particle concentration data of the lithium battery production area in real time and divide the environmental cleanliness level according to the preset standard. The divided environmental cleanliness level related information will be sent to the control module 120. The control module 120 is also configured to construct the relationship database of the environmental cleanliness level and the puncture strength of the diaphragm according to the environmental cleanliness level required by the lithium battery production. Optionally, in some embodiments of the present application, the monitoring module 110 can use a dust particle counter to collect the number of particles of a specific particle size per unit volume in the lithium battery production area in real time. According to the number of particles, the environmental cleanliness is divided into multiple environmental cleanliness levels.

[0074] On the basis of establishing the relationship database of the environmental cleanliness level and the puncture strength of the diaphragm, the control module 120 will determine the environmental cleanliness level required by the current lithium battery production according to the real-time monitoring of the monitoring module 110, and generate a diaphragm selection instruction matched with the current environmental cleanliness according to the relationship database of the environmental cleanliness and the puncture strength of the diaphragm. The diaphragm selection instruction will be sent to the feeding module 130. The feeding module 130 is configured to store multiple diaphragm materials with different puncture resistance strengths. After receiving the diaphragm selection instruction, the feeding module 130 will select the diaphragm material with the corresponding puncture resistance strength according to the current environmental cleanliness.

[0075] In addition, the execution module 140 is configured to complete other procedures in the complete lithium battery production scene. Specifically, the execution module 140 is configured to assemble the diaphragm, the positive plate and the negative plate to form a roll core, and then perform welding, baking, liquid injection and activation procedures to complete the assembly of the lithium battery. According to the difference of the diaphragm material, the required process parameters may be different in the specific production process. Therefore, the control module 120 is also configured to adjust the process parameters of the execution module 140 according to the puncture resistance strength of the diaphragm material currently selected by the feeding module 130.

[0076] Optionally, in some embodiments of the present application, the control module 120 is further configured to analyze historical environment data, predict the variation trend of the environment cleanliness in the future production period, and in the case of predicting a downward trend of the environment cleanliness, control the supply module 130 to pre-load the separator with higher puncture resistance, and trigger a pre-command to adjust the process parameters of the lithium battery production equipment, which will be sent to the execution module 140 to complete the corresponding adjustment. It should be noted that when the supply module 130 has selected the separator material according to the current environment cleanliness, but the actual separator material has not yet been put into production, in the case of the control module 120 also predicting that the environment cleanliness will have a downward trend, it is necessary to determine whether the currently selected separator material meets the future cleanliness requirement. If it meets, there is no need to load the separator with higher puncture resistance, and if it does not meet, the separator with higher puncture resistance is loaded.

[0077] Optionally, in some embodiments of the present application, the assembled battery also needs to be subjected to quality detection and other processes, which are implemented by the control module 120. Specifically, the control module 120 is further configured to: perform quality detection on the assembled lithium battery, in the case of detecting that the separator is punctured or short-circuited due to particulate pollution, determine the target process of the puncture event according to the production time stamp of the abnormal battery; trace the historical environment cleanliness level of the target process at the puncture event occurrence period based on the production time stamp; count the separator puncture rate at the historical environment cleanliness level in the historical database; in the case that the separator puncture rate reaches a preset threshold, improve the puncture strength of the separator corresponding to the environment cleanliness level; correct the relationship database between the environment cleanliness level and the puncture strength of the separator based on the improved puncture strength of the separator; and reload the separator material adapted to the current environment cleanliness according to the corrected relationship database. In these embodiments, the quality detection is performed by the control module 120, the relationship database is updated, which is conducive to improving the reliability and economy of lithium battery manufacturing.

[0078] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application. Those skilled in the art can make various modifications and decorations without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application is defined by the scope of the claims.

Claims

1. A method for manufacturing a lithium battery, characterized in that: include: Determine the environmental cleanliness level required for current lithium battery production; According to the environmental cleanliness level, a diaphragm material with corresponding puncture resistance strength is selected.

2. The lithium battery manufacturing method according to claim 1, characterized in that: The lithium battery manufacturing method further includes: Collecting particle concentration data in the lithium battery production area in real time, and classifying the environmental cleanliness level according to preset standards based on the particle concentration data; According to the environmental cleanliness level required for lithium battery production, a relational database corresponding to the environmental cleanliness level and the diaphragm puncture strength is constructed.

3. The lithium battery manufacturing method according to claim 2, characterized in that: The real-time collection of particle concentration data in the lithium battery production area and the classification of environmental cleanliness levels according to preset standards based on the particle concentration data include: The number of particles of a specific particle size per unit volume in the lithium battery production area is collected in real time, and the environmental cleanliness is divided into multiple environmental cleanliness levels according to the number of particles.

4. The method for manufacturing a lithium battery according to claim 2, wherein: The relational database corresponding to the cleanliness level of the constructed environment and the puncture resistance strength of the diaphragm includes: As the value of the environmental cleanliness level increases, a diaphragm material with higher puncture resistance is matched.

5. The lithium battery manufacturing method according to claim 1, characterized in that: The environmental cleanliness levels include: ISO class 4, ISO Class 5, ISO Class 7, ISO Class 8 and ISO Class 9, and the corresponding puncture resistance strength of the diaphragm material is ≥0.13N / μm, ≥0.20N / μm, ≥0.5N / μm, ≥0.7N / μm and ≥1.2N / μm respectively.

6. The lithium battery manufacturing method according to claim 2, characterized in that: After selecting a diaphragm material having a corresponding puncture resistance strength according to the environmental cleanliness level, the lithium battery manufacturing method includes: According to the puncture resistance of the currently selected diaphragm material, the process parameters of the lithium battery production equipment are adjusted, the diaphragm, positive electrode sheet and negative electrode sheet are assembled to form a roll core, and then welding, baking, liquid injection and activation processes are carried out to complete the assembly of the lithium battery.

7. The method for manufacturing a lithium battery according to claim 2, wherein: The lithium battery manufacturing method further includes: Analyze historical environmental data and predict the trend of environmental cleanliness changes during future production periods; When it is predicted that the environmental cleanliness will tend to decline, a diaphragm with higher puncture resistance is preloaded, and pre-instructions for adjusting the process parameters of the lithium battery production equipment are triggered.

8. The lithium battery manufacturing method according to claim 6, characterized in that: The lithium battery manufacturing method further includes: Perform quality inspection on assembled lithium batteries. If a diaphragm breakdown or short circuit caused by particulate contamination is detected, the target process where the breakdown event occurred is determined based on the production timestamp of the abnormal battery. Tracing back the historical environmental cleanliness level of the target process during the period when the breakdown event occurred based on the production timestamp; Calculate the breakdown rate of all diaphragms in the historical environmental cleanliness level in the historical database; When the diaphragm breakdown rate reaches a preset threshold, the diaphragm puncture strength corresponding to the environmental cleanliness level is increased; Correcting the relationship database between the environmental cleanliness level and the diaphragm puncture strength based on the improved diaphragm puncture strength; The diaphragm material adapted to the current environmental cleanliness level is reloaded according to the revised relational database.

9. The lithium battery manufacturing method according to claim 1, characterized in that: The lithium battery manufacturing method further includes: In parallel production scenarios, diaphragm material priorities are divided according to the cleanliness requirements of each process; When there is a conflict in the cleanliness requirements of different processes, the diaphragm feed distribution strategy is adjusted according to the hierarchical order of electrode preparation - battery cell assembly - formation testing.

10. A lithium battery manufacturing device, characterized in that: include: a control module configured to determine a required environmental cleanliness level for current lithium battery production; The feeding module is configured to select a diaphragm material with corresponding puncture resistance strength according to the environmental cleanliness level.

11. The lithium battery manufacturing device according to claim 10, characterized in that: The device further comprises: A monitoring module configured to collect particle concentration data of the lithium battery production area in real time, and classify the environmental cleanliness level according to preset standards based on the particle concentration data; The control module is further configured to construct a relational database corresponding to the environmental cleanliness level and the diaphragm puncture strength according to the environmental cleanliness level required for lithium battery production.

12. The lithium battery manufacturing device according to claim 10, characterized in that: The device further comprises: an execution module configured to assemble the separator, the positive electrode sheet, and the negative electrode sheet into a coil core, and then perform welding, baking, liquid injection, and activation processes to complete the assembly of the lithium battery; The control module is further configured to adjust the process parameters of the execution module according to the puncture resistance strength of the diaphragm material currently selected by the feeding module.

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