Electrolyte infiltration method and system
By sorting the cores by weight and arranging them in a gradient manner, combined with intelligent static setting process and electrolyte replenishment, the problem of inconsistent electrolyte wetting effect was solved, thereby improving battery capacity and cycle life.
Patent Information
- Application Number
- CN202511701517.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-01-27
AI Technical Summary
In existing technologies, the electrolyte wetting effect is affected by batch differences in the core, resulting in poor battery capacity consistency and cycle life. Furthermore, the settling process cannot meet the needs of cells with both small and large porosities.
Before electrolyte injection, the cores are sorted by weight and divided into gradient groups. Intelligent tray assembly and static process matching are performed according to the weight groups. After the cycle is completed, weighing and electrolyte replenishment are performed to ensure that the electrolyte content meets the standard.
It achieves consistent control of electrolyte wetting effect, improves battery capacity consistency and cycle life, and solves the problem of batch differences between individual batteries.
Smart Images
Figure CN121416632A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery manufacturing technology, and specifically to an electrolyte wetting method and system. Background Technology
[0002] This application relates to the post-filling settling process in the field of battery cell manufacturing. After one filling, the battery cavity contains electrolyte. The settling cycle process accelerates the wetting of the electrolyte in the electrode gaps and separator gaps by differential pressure or equal pressure. Poor wetting effect will affect the formation of SEI in the battery, and affect the battery capacity consistency, cycle life, etc.
[0003] In the manufacturing process of lithium-ion batteries, the electrolyte wetting effect is a key process node that determines the electrochemical performance.
[0004] In existing technologies, the post-injection settling process generally uses fixed process parameters, which has two key drawbacks: (1) Ignore the batch differences in the micropore structure of the core; after the previous coating, rolling and slitting processes, the key parameters such as electrode surface roughness and membrane porosity of different cores are subject to process fluctuations, resulting in significant differences in electrolyte diffusion coefficient. (2) When the same batch of cells adopts the same static parameters, cells with smaller porosity are prone to forming wettable dead zones due to insufficient capillary force, which directly affects the uniformity of the SEI film; while cells with larger porosity cause redundant electrolyte retention time due to oversaturated adsorption, which seriously affects the production line cycle. Summary of the Invention
[0005] The technical problem to be solved by this invention is: how to solve the impact of batch differences in core material on the electrolyte wetting effect.
[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: An electrolyte wetting method includes the following steps: S1. Deploy a high-precision weight sorting module at the pre-injection station to model the weight spectrum of the core and divide the core into different weight groups according to the corresponding gradient units. S2. Intelligently group the battery cells of the same weight group, and send them into the liquid injection device for liquid injection after the full group is filled. S3. After one injection, the cells are sent into the bell jar settling chamber according to their weight group and the corresponding settling cycle process is matched for operation. S4. After standing, the cells are weighed again, and cells with low electrolyte levels are replenished to ensure that the electrolyte content of the cells entering the formation process meets the standard.
[0007] This invention marks the core weight of the battery cells before electrolyte injection, classifies them according to different weight gradients, and reassembles the cells of different gradients. After electrolyte injection, the cells are sent to the corresponding static chamber for circulation. After circulation, they are weighed again, and cells with insufficient electrolyte are replenished to ensure that the electrolyte content of the battery entering the formation process meets the standard. This method achieves full-dimensional consistency control from macroscopic electrolyte injection volume to microscopic pore filling, providing process assurance for battery interface stability. It also solves the problem of batch differences between individual batteries affecting electrolyte wetting effect, improving battery capacity consistency and cycle life.
[0008] As a further aspect of the present invention, the specific process of step S1 is as follows: S11. A weight sensor is used to weigh the battery cells at the cutting and unloading station and mark the cores to facilitate core pairing and weight tracking when they are put into the casing. S12. Perform data analysis on a predetermined number of qualified battery cells, establish a batch weight normal distribution model, divide the cores into several weight groups according to each predetermined weight as a gradient unit, and bind the data of the duplicate groups to the battery code.
[0009] As a further aspect of the present invention, the specific process of step S2 is as follows: S21. Scan the barcode of qualified incoming batteries before liquid injection and group them by weight. S22. Use a robotic arm to grab the cells in the same group and place them into the same tray. Assign the tray a grouping data for cell weight. Once the tray is full, send it to the liquid injection machine for one liquid injection.
[0010] As a further aspect of the present invention, the specific process of step S3 is as follows: S31. After the liquid injection is completed, the full tray flows into the liquid injection bell jar settling chamber through the logistics line. The bell jar scanning device scans the tray and reads the weight grouping data of the battery cells loaded on the tray. S32. Based on the read group data, issue the corresponding static cycle process; The difference between the static cycling process corresponding to S33 and the repeating group lies in the difference in cycle time and vacuum degree. The actual parameters set need to be verified on-site according to the specific cell model before input.
[0011] As a further aspect of the present invention: the core resting and cycling process in step S33 is as follows: S331. Vacuum evacuation inside the bell jar ≤ -80±10kPa, pressure holding time is 90~120s; S332. The bell jar is pressurized in three stages: the first stage is pressurized at 100±10 kPa and held for 4 to 6 seconds; the second stage is pressurized at 200±10 kPa and held for 4 to 6 seconds; the third stage is pressurized at 300±10 kPa and held for 220 to 300 seconds. S333, the rear bell jar is vented to the atmosphere at 0±5 kPa; S334, Repeat steps S331-S333 three times; S335, then pressurize the bell jar to 200±10kpa and hold the pressure for 100~120s; S336, the rear bell jar is vented to the atmosphere at 0±5 kPa.
[0012] As a further aspect of the present invention, the specific process in step S4 is as follows: S41. After settling, a second weighing is performed using a high-precision quality detection module, and the data is recorded to assess the actual electrolyte content. S42. If the electrolyte content deviation is greater than the preset value, the cell will start a quantitative electrolyte replenishment program. The replenishment accuracy will be controlled within the preset accuracy to ensure that the electrolyte addition amount meets the process standard. S43. After replenishing the electrolyte, re-inspect the quality of the battery cells. Only after confirming that the electrolyte level meets the standard can the cells be transferred to the formation process.
[0013] This invention also discloses an electrolyte wetting system based on the weight gradient of battery cores, comprising: Core sorting module: This module is used to deploy a high-precision weight sorting module at the pre-injection station. It performs weight spectrum modeling on the core weight and divides the core into different weight groups according to the corresponding gradient units. The tray assembly module is used to intelligently assemble cells of the same weight group into trays. Once the tray is full, it is sent to the electrolyte injection device for one electrolyte injection. Liquid injection module: After a single liquid injection, the battery cells are sorted by weight group and sent into the bell jar for operation, matching the corresponding static cycle process. Re-weighing and electrolyte replenishment module: used to weigh the cells again after they have been left to stand, and to replenish the electrolyte in cells with low electrolyte levels, so as to ensure that the electrolyte content of the cells entering the formation process meets the standard.
[0014] As a further aspect of the present invention: the core sorting module includes: Weight marking unit: Using a weight sensor, the battery cells are weighed at the cutting and unloading station and the cores are marked to facilitate core pairing and weight tracking when they are put into the casing. Grouping Unit: Used to perform data analysis on a preset number of qualified battery cells, establish a normal distribution model of batch weight, divide the cores into several weight groups according to each preset weight as a gradient unit, and bind the data of duplicate groups to the battery code.
[0015] As a further aspect of the present invention: the disk assembly module includes: Scanning and grouping unit: Used to scan the barcodes of qualified incoming batteries before liquid filling and group them by weight; Liquid injection unit: The same group of cells is picked up by a robotic arm and placed into the same tray. The tray is assigned a grouping data of cell weight. Once the tray is full, it is sent to the liquid injection machine for liquid injection.
[0016] As a further aspect of the present invention: the injection module includes: Reading unit: After the liquid injection is completed, the full tray flows into the liquid injection bell jar settling chamber from the logistics line. The bell jar barcode scanning device scans the tray and reads the group data of the cell weight loaded on the tray. Based on the read group data, the corresponding settling cycle process is issued. Pre-processing unit before cyclic operation: used for the static cyclic process corresponding to the repetitive group. The difference lies in the cycle time and vacuum degree. The actual parameters set need to be verified on-site according to the specific cell model before input.
[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention marks the core weight of the battery cells before electrolyte injection, classifies them according to different weight gradients, and reassembles the cells of different gradients. After electrolyte injection, the cells are sent to a bell jar for circulation in the corresponding settling process. After circulation, the cells are weighed again, and cells with insufficient electrolyte are replenished to ensure that the electrolyte content of the battery entering the formation process meets the standard. This method achieves full-dimensional consistency control from macroscopic electrolyte injection volume to microscopic pore filling, providing process assurance for battery interface stability. It also solves the problem of batch differences between individual batteries affecting the electrolyte wetting effect, improving the consistency of battery capacity and the cycle life of the battery. Attached Figure Description
[0018] Figure 1 This is a flowchart of an embodiment of the intelligent static control method based on battery core weight gradient of the present invention; Figure 2 This is a schematic diagram illustrating the normal distribution analysis of core weight according to an embodiment of the present invention; Figure 3 This is a diagram of an intelligent static control system based on the weight gradient of battery cores, as described in an embodiment of the present invention. Detailed Implementation To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] Example 1 Reference Figure 1 An electrolyte wetting method, specifically a dynamic gradient adaptation static settling process based on core weight spectrum analysis, includes the following steps: S1. Deploy a high-precision weight sorting module at the pre-injection station to perform weight spectrum modeling on the core weight and divide the core into different weight groups according to the corresponding gradient units.
[0020] It should be noted that the specific process of step S1 is as follows: S11. A dual-channel MEMS resonant weight sensor is used to weigh the battery cells at the cutting and unloading station and mark the cores to facilitate core pairing and weight tracking when the cores are put into the casing. S12. Analyze the data from 1000 consecutive qualified battery cells and establish a batch weight normal distribution model (refer to...). Figure 2 The cores are divided into three weight groups (A, B, and C) in increments of 6g, and the group data (A / B / C) is bound to the battery code; that is, each battery has its own battery code during the production process, which is used to record relevant information about the battery during the manufacturing process.
[0021] Figure 2 The graph shows the normal distribution of the core weight, with the horizontal axis representing weight and the vertical axis representing the probability density function, i.e., the probability of each possible value. The middle bars represent the probability density function being constant within the interval, and the bars are rectangular. The black dashed lines in the graph represent the weight grouping mentioned in S12, which divides the core into three groups: A, B, and C, each consisting of 6g of weight. The curve is the fitted curve of the normal distribution.
[0022] S2. Intelligently group the battery cells of the same weight group, and send them into the liquid injection device for liquid injection after the tray is full.
[0023] It should be noted that the specific process of step S2 is as follows: S21. Scan the barcode of qualified incoming batteries before liquid injection and group them by weight. S22. Use a robotic arm to grab the cells in the same group and place them into the same tray. Assign the tray a grouping data for cell weight. Once the tray is full, send it to the liquid injection machine for one liquid injection.
[0024] S3. After one injection, the cells are sent into the bell jar according to their weight group and matched with the corresponding static cycle process for operation.
[0025] It should be noted that the specific process of step S3 is as follows: S31. After the liquid injection is completed, the full tray flows into the liquid injection bell jar settling chamber through the logistics line. The bell jar scanning device scans the tray and reads the weight grouping data of the battery cells loaded on the tray. S32. Based on the read group data, issue the corresponding static cycle process; The differences between the static cycling processes corresponding to groups S33 and A / B / C lie in the cycle time (i.e., the holding time mentioned below) and the vacuum degree. The actual parameters set need to be verified on-site according to the specific cell model before input.
[0026] Among them, the static circulation process corresponding to A / B / C is: Group A cores are lightweight with large gaps between them, allowing for shorter cycle times under the same pressure as Groups B and C, thus ensuring complete electrolyte wetting. Group B cores are of medium weight and constitute the majority, requiring a medium settling time. Group C cores are of the highest weight with small gaps, necessitating a longer positive pressure holding time to ensure complete electrolyte wetting.
[0027] Specifically, the static cycle process for quality group A core is as follows:
[0028] Specifically, the static cycle process for quality group B cores is as follows:
[0029] Specifically, the static cycle process for quality group C core is as follows:
[0030] S4. After standing, the cells are weighed again, and cells with low electrolyte levels are replenished to ensure that the electrolyte content of the cells entering the formation process meets the standard.
[0031] It should be noted that the specific process in step S4 is as follows: S41. After settling, a second weighing is performed using a high-precision quality detection module (resolution ±0.01g), and the data is recorded to assess the actual electrolyte content. Note that there will be a weighing before electrolyte injection, and the actual content is calculated by the weight difference before and after electrolyte injection. S42. For electrolyte levels deviating by >1.5%, initiate a quantitative electrolyte replenishment procedure for the battery cell, with replenishment accuracy controlled within ±0.05ml. Ensure the electrolyte addition amount meets process standards. Regarding the electrolyte replenishment procedure: For cells with low electrolyte levels, they are transferred to the electrolyte replenishment unit for automatic replenishment. The replenishment unit is equipped with a weighing sensor to weigh the low-electrolyte cells and a barcode scanner to obtain weight information by scanning the battery code. It automatically calculates the weight difference and replenishes the electrolyte accordingly. After replenishment, the weight is retested. For cells with high electrolyte levels, excess electrolyte is manually squeezed out of the large surface area and wiped clean in time. Then, the cells are manually weighed and put into the electrolyte replenishment machine for processing according to the "replenishment procedure for low-electrolyte cells".
[0032] S43. After replenishing the electrolyte, re-inspect the quality of the battery cell. Only after confirming that the electrolyte level meets the standard can the cell be transferred to the formation process to avoid affecting the subsequent performance or safety of the battery cell due to abnormal electrolyte level.
[0033] Example 2 This invention also discloses an electrolyte wetting system based on the weight gradient of battery cores, comprising: Core sorting module: This module is used to deploy a high-precision weight sorting module at the pre-injection station. It performs weight spectrum modeling on the core weight and divides the core into different weight groups according to the corresponding gradient units. The core sorting module includes a weight marking unit and a grouping unit; The weight marking unit uses a weight sensor to weigh the battery cells at the cutting and unloading station and mark the cores to facilitate core pairing and weight tracking when they are put into the casing. The grouping unit is used to perform data analysis on a consecutive preset number of qualified battery cells, establish a batch weight normal distribution model, divide the core into several weight groups according to each preset weight as a gradient unit, and bind the data of the duplicate groups to the battery code.
[0034] The tray assembly module is used to intelligently assemble cells of the same weight group into trays. Once the tray is full, it is sent to the electrolyte injection device for one electrolyte injection. The tray assembly module includes a barcode scanning and grouping unit and a liquid injection unit; Scanning and grouping unit: Used to scan the barcodes of qualified incoming batteries before liquid filling and group them by weight; Liquid injection unit: The same group of cells is picked up by a robotic arm and placed into the same tray. The tray is assigned a grouping data of cell weight. Once the tray is full, it is sent to the liquid injection machine for liquid injection.
[0035] Liquid injection module: After a single liquid injection, the battery cells are sorted by weight group and sent into the bell jar for operation, matching the corresponding static cycle process. The injection module includes a reading unit and a pre-processing unit for cyclic operations; Reading unit: After the liquid injection is completed, the full tray flows into the liquid injection bell jar settling chamber from the logistics line. The bell jar barcode scanning device scans the tray and reads the group data of the cell weight loaded on the tray. Based on the read group data, the corresponding settling cycle process is issued. Pre-processing unit before cyclic operation: used for the static cyclic process corresponding to the repetitive group. The difference lies in the cycle time and vacuum degree. The actual parameters set need to be verified on-site according to the specific cell model before input.
[0036] Re-weighing and electrolyte replenishment module: used to weigh the cells again after they have been left to stand, and to replenish the electrolyte in cells with low electrolyte levels, so as to ensure that the electrolyte content of the cells entering the formation process meets the standard.
[0037] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. An electrolyte wetting method, characterized in that, Includes the following steps: S1. Deploy a high-precision weight sorting module at the pre-injection station to model the weight spectrum of the core and divide the core into different weight groups according to the gradient unit. S2. Intelligently group the cells of the same weight group into a tray, and after the tray is full, send it into the liquid injection device for liquid injection. S3. After one injection, the battery cells are sent into the bell jar according to their weight group and matched with the corresponding static circulation process for operation. S4. After standing, the cells are weighed again, and cells with low electrolyte levels are replenished to ensure that the electrolyte content of the cells entering the formation process meets the standard.
2. The electrolyte wetting method according to claim 1, characterized in that, The specific process of step S1 is as follows: S11. A weight sensor is used to weigh the battery cells at the cutting and unloading station and mark the cores to facilitate core pairing and weight tracking when they are put into the casing. S12. Perform data analysis on a predetermined number of qualified battery cells, establish a batch weight normal distribution model, divide the cores into several weight groups according to each predetermined weight as a gradient unit, and bind the data of the duplicate groups to the battery code.
3. The electrolyte wetting method according to claim 1, characterized in that: The specific process of step S2 is as follows: S21. Scan the barcode of qualified incoming batteries before liquid injection and group them by weight. S22. Use a robotic arm to grab the cells in the same group and place them into the same tray. Assign the tray a grouping data for cell weight. Once the tray is full, send it to the liquid injection machine for one liquid injection.
4. The electrolyte wetting method according to claim 1, characterized in that: The specific process of step S3 is as follows: S31. After the liquid injection is completed, the full tray flows into the liquid injection bell jar settling chamber through the logistics line. The bell jar scanning device scans the tray and reads the weight grouping data of the battery cells loaded on the tray. S32. Based on the read group data, issue the corresponding static cycle process; The difference between the static cycling process corresponding to S33 and the repeating group lies in the difference in cycle time and vacuum degree. The actual parameters set need to be verified on-site according to the specific cell model before input.
5. The electrolyte wetting method according to claim 4, characterized in that, The core resting and cycling process is as follows: S331. Vacuum evacuation inside the bell jar ≤ -80±10kPa, pressure holding time is 90~120s; S332. The bell jar is pressurized in three stages: the first stage is pressurized at 100±10 kPa and held for 4 to 6 seconds; the second stage is pressurized at 200±10 kPa and held for 4 to 6 seconds; the third stage is pressurized at 300±10 kPa and held for 220 to 300 seconds. S333, the rear bell jar is vented to the atmosphere at 0±5 kPa; S334, Repeat steps S331-S333 three times; S335, then pressurize the bell jar to 200±10kpa and hold the pressure for 100~120s; S336, the rear bell jar is vented to the atmosphere at 0±5 kPa.
6. The electrolyte wetting method according to claim 1, characterized in that, The specific process in step S4 is as follows: S41. After settling, a second weighing is performed using a high-precision quality detection module, and the data is recorded to assess the actual electrolyte content. S42. If the electrolyte content deviation is greater than the preset value, the cell will start a quantitative electrolyte replenishment program. The replenishment accuracy will be controlled within the preset accuracy to ensure that the electrolyte addition amount meets the process standard. S43. After replenishing the electrolyte, re-inspect the quality of the battery cells. Only after confirming that the electrolyte level meets the standard can the cells be transferred to the formation process.
7. An electrolyte wetting system based on the weight gradient of battery cores, characterized in that, include: Core sorting module: This module is used to deploy a high-precision weight sorting module at the pre-injection station. It performs weight spectrum modeling on the core weight and divides the core into different weight groups according to gradient units. The tray assembly module is used to intelligently assemble cells of the same weight group into trays. Once the tray is full, it is sent to the electrolyte injection device for one electrolyte injection. Liquid injection module: After a single liquid injection, the battery cells are sorted by weight group and sent into the bell jar for operation, matching the corresponding static cycle process. Re-weighing and electrolyte replenishment module: used to weigh the cells again after they have been left to stand, and to replenish the electrolyte in cells with low electrolyte levels, so as to ensure that the electrolyte content of the cells entering the formation process meets the standard.
8. The electrolyte wetting system based on the weight gradient of the battery core according to claim 7, characterized in that, The core sorting module includes: Weight marking unit: Using a weight sensor, the battery cells are weighed at the cutting and unloading station and the cores are marked to facilitate core pairing and weight tracking when they are put into the casing. Grouping Unit: Used to perform data analysis on a preset number of qualified battery cells, establish a normal distribution model of batch weight, divide the cores into several weight groups according to each preset weight as a gradient unit, and bind the data of duplicate groups to the battery code.
9. The electrolyte wetting system based on the weight gradient of the battery core according to claim 7, characterized in that, The disk assembly module includes: Scanning and grouping unit: Used to scan the barcodes of qualified incoming batteries before liquid filling and group them by weight; Liquid injection unit: The same group of cells is picked up by a robotic arm and placed into the same tray. The tray is assigned a grouping data of cell weight. Once the tray is full, it is sent to the liquid injection machine for liquid injection.
10. The electrolyte wetting system based on the weight gradient of the battery core according to claim 7, characterized in that, The injection module includes: Reading unit: After the liquid injection is completed, the full tray flows into the liquid injection bell jar settling chamber from the logistics line. The bell jar barcode scanning device scans the tray and reads the group data of the cell weight loaded on the tray. Based on the read group data, the corresponding settling cycle process is issued. Pre-processing unit before cyclic operation: used for the static cyclic process corresponding to the repetitive group. The difference lies in the cycle time and vacuum degree. The actual parameters set need to be verified on-site according to the specific cell model before input.