Repair method of power battery

Abstract

The invention relates to the field of power battery disassembly, and discloses a power battery repair method which comprises the following steps: confirming repair content, and confirming an accessory disassembly path, welding repair parameters and glue repair parameters according to the repair content; when welding repair is carried out, electrical paths among the modules are cut off, whole package protection and a to-be-repaired module are carried out, then pole bar pieces are drilled and milled according to welding repair parameters, CCS or bar pieces and pole hole repair are dismantled, and finally pole grinding is carried out; when glue repair is executed, battery peripheral accessories are disassembled, a problem module is separated, whole package protection treatment is carried out, and glue on the bottom surface of the box body and glue on the side face of the bottom of the box body are removed according to glue repair parameters. According to the invention, the problems of difficult disassembly, low disassembly efficiency, easy short circuit and low yield of a glue bonding part and a welding connection part when the battery is repaired in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the field of power battery disassembly, and in particular to a power battery repair method. Background Art

[0002] With the rapid development of the new energy vehicle industry, power batteries, as core components, are receiving increasing attention for their reliability and maintainability. In the manufacturing process of power batteries, two common fixing methods are glue bonding and welding. For example, the power battery module and cold plate, as well as the power battery module and the casing, are both bonded with glue. This glue-based connection method, relying on the intermolecular forces of high-molecular polymers, forms a high-strength connection interface after curing, offering high structural strength and good insulation properties. However, it is not conducive to later repairs. The CCS (flexible circuit collection board) and the battery cell are fixedly connected to the battery cell by welding, which provides relatively high structural strength.

[0003] However, in actual applications, the above connection method has the following problems during the subsequent repair process: 1. Problems with glue bonding repair: (1) Uncontrollable regional diffusion: For glue bonding locations, existing technologies mainly use disassembly by soaking in a disassembly agent. The disassembly agent is a fluid and conductor with low surface tension. It will diffuse along the bonding gap under capillary action. Due to the lack of effective control measures, the disassembly agent can easily spread to areas that do not require rework, causing diffusion to affect areas that do not require rework; (2) There are electrical safety risks: In extreme cases, short circuits or other abnormal conditions may occur due to poor control of the disassembly agent; (3) Poor process compatibility: The disassembly agent requires a long soaking time (usually >4 hours) and is only applicable to the overall disassembly of the battery pack. It cannot achieve module-level local rework, which greatly increases the repair cost.

[0004] 2. Problems with repair using welded connections: (1) Difficulty in disassembly: Due to the high strength of welded joints, mechanical stripping with tools such as pliers is required for disassembly. This operation is not only cumbersome and time-consuming, but also results in slow repair progress and low battery repair efficiency. (2) Safety risks: Because the operating force and angle are difficult to control accurately, tools such as pliers can easily damage the battery cell poles or CCS lines during the forceful stripping process, and may even cause safety risks such as short circuits.

[0005] The present invention aims to provide a power battery repair method to solve the problems in the prior art of difficult disassembly, low disassembly efficiency, easy short circuit and low yield of glue-bonded parts and welded connection parts during battery repair.

[0006] To solve the above-mentioned problem, the present invention adopts the following technical solution: A method for repairing a power battery, comprising the following steps: Step S100: confirm the repair content; Step S200: confirming an accessory removal path and repair parameters according to the repair content, wherein the accessory removal path includes a welding repair path and a glue repair path, and the repair parameters include welding repair parameters and glue repair parameters; Step S300: performing the removal operation of the welding repair path, including the following steps: Step S310: Remove the output copper busbar and the module series copper busbar in sequence, cut off the electrical path between the modules, and separate the single module or part of the module to be repaired from the overall circuit; Step S320: Using insulating tape to protect the entire module to be repaired, then hoisting the module to be repaired to the drilling machine, and defining the position of the module to be repaired by using a positioning fixture; Step S330: Based on the welding repair parameters, the disassembly operation is performed using a drill press and a grinding gun on the same set of equipment. When disassembling the problematic battery, the drilling and milling of the drill press and the grinding gun are used to collaboratively remove the terminal tabs, remove the CCS or tabs, and clean the aluminum shavings to expose the specific location to be repaired. Step S340: Performing a whole-package protective treatment on the unrepaired parts, obtaining grinding data, repairing the pole hole and grinding the pole according to the grinding data, and cleaning the debris to complete the removal of the welding repair path; Step S400: performing accessory disassembly of the glue rework path; which includes the following steps: Step S410: dismantling the basic accessories around the power battery to expose the module; Step S420: dismantling the modules and separating the modules with glue bonding problems; Step S430: Using insulating tape to protect the non-repaired parts, the module to be repaired is then hoisted onto the drilling machine workbench and the position of the module to be repaired is defined by a positioning fixture; Step S440: According to the glue repair parameters, use the drill press and grinder on the same set of equipment to perform disassembly operations; when performing the disassembly operation of the problem battery, the drill press and the grinder are used to collaboratively remove the glue on the bottom surface of the box and the glue on the bottom side of the box to complete the removal of the glue repair path.

[0007] The principle of this solution is: first, the returned power battery is inspected to confirm the repair content, and the accessory removal path and repair parameters are confirmed based on the repair content, and the returned battery is removed in a regional manner. Among them, for the positions connected by welding connection, the output copper bus and the module series copper bus are first removed in turn to cut off the electrical path between the modules, so that the single module or part of the module to be repaired is separated from the overall circuit; then, the module to be repaired is protected as a whole with insulating tape, and the module to be repaired is hoisted and fixed on the drilling machine workbench. After that, the welding repair parameters are flexibly adjusted according to the actual connection structure and material thickness, and the drilling and milling of the drilling machine and the grinding gun are used to collaboratively remove the pole bar and remove the CCS or bar. That is, the drilling machine is first used to preliminarily separate the connection parts. After drilling and milling are completed, the remaining welding slag and metal burrs are finely ground with a grinding gun to ensure effective separation of the connection parts, and make the surface smooth and flat, eliminating the safety hazards caused by sharp edges. After that, the aluminum chips are cleaned to expose the specific position to be repaired. Finally, the unrepaired part is protected as a whole, and the grinding data is obtained. The pole hole is repaired and the pole is ground according to the grinding data, and the debris is cleaned, thereby completing the removal of the welding repair path.

[0008] For the locations connected by glue bonding, first remove the basic accessories around the power battery in turn to expose the module, then remove the module and separate the module where the glue bonding problem occurs. Next, use insulating tape to protect the non-repaired parts to prevent unnecessary damage during operation. Then flexibly adjust the glue repair parameters according to the actual connection structure and material thickness. First, use a drill press to drill and mill the glue on the bottom surface of the box and the glue on the bottom side of the box to preliminarily remove the main glue layer; after drilling and milling, use a grinding gun to finely grind the remaining glue to ensure effective separation of the connecting parts, and make the surface smooth and flat, eliminating the safety hazards caused by sharp edges, and finally clean up the aluminum chips to complete the removal of the glue repair path.

[0009] The advantages of this solution are: (1) This solution breaks the technical prejudice that "welding repair and glue repair must use different treatment methods". It innovatively proposes the use of "drilling and milling + grinding gun grinding". Through the reasonable selection of tools, process parameters and protective treatment, the use of physical processing methods can also efficiently handle the two different types of connection repairs, welding and glue, and realize the integrated treatment of welding repair and glue repair. It not only solves the inefficiency problem of traditional methods, but also improves the repair quality.

[0010] (2) This solution provides a universal solution that can handle welding rework and glue rework with the same set of equipment (drilling machine + grinding gun), which greatly simplifies the rework process, improves rework efficiency, and facilitates standardized operations, achieving process repeatability and controllability, thereby improving the consistency and yield rate of rework quality.

[0011] (3) This solution not only solves the problems of low efficiency, large damage and high risk in existing repair technologies through the coordinated operation of drilling, milling and grinding as well as dynamic parameter adjustment, but also demonstrates obvious advantages in energy saving, environmental protection and maintainability.

[0012] (4) This solution achieves controllable demolition areas by dividing the welding and gluing areas according to the repair content.

[0013] (5) This solution effectively prevents foreign matter contamination and damage by implementing whole-package protection treatment during the repair process, and achieves controllable foreign matter during the demolition process; at the same time, it reduces the risk of short circuits and achieves controllable safety risks during the demolition process; in addition, it controls the spread of pollutants at the source, significantly reduces the subsequent cleaning intensity and time cost, and makes the repair process more efficient and neat.

[0014] Preferably, as an improvement, the rework content includes rework type and rework location; the rework type includes welding rework and glue rework; the welding rework includes FPC rework and welding defect rework, and the glue rework includes heating film defect rework and battery cell defect rework; the rework location refers to the internal area of ​​the battery pack where the rework operation is specifically required.

[0015] Beneficial effects: Breaking down the repair content into "type + location" helps to quickly identify the cause of the fault and the scope of impact, allowing maintenance personnel to prepare tools, materials and process parameters in a targeted manner, reducing invalid operations and improving the accuracy and efficiency of repair work.

[0016] Preferably, as an improvement, step S100 includes the following steps: Step S110: performing fault detection on the returned battery and obtaining the fault detection result; Step S120: confirming the repair type and repair location of the battery to be repaired according to the fault detection result.

[0017] Beneficial effects: Through fault detection, specific problems with the battery can be accurately identified, avoiding blind disassembly or misjudgment of faults; based on the fault detection results, the type of repair (such as welding repair or glue repair) and the specific repair location (such as FPC, heating film, etc.) are clearly defined, which helps maintenance personnel quickly formulate repair strategies and reduce unnecessary process switching and resource waste.

[0018] Preferably, as an improvement, step S330 includes the following steps: Step S331: First, drill and mill the pole tab at a high speed until the remaining thickness of the drilled and milled surface is 1mm-2mm. Then, drill and mill at a slow speed until a clear gap appears on the drilled and milled surface. At this point, stop drilling and milling, use a grinding gun to remove residual welding slag and metal burrs, and clean up the generated aluminum chips. Step S332: Repeat step S331, remove the CCS or the bar, and clean the aluminum chips to expose the specific location to be repaired.

[0019] Beneficial effects: (1) Rapid drilling and milling can efficiently remove most of the material, and then switching to slow drilling and milling helps to accurately control the processing depth, avoid excessive milling and damage to the pole, and thus achieve efficient and safe separation operations; (2) Staged drilling and milling combined with grinding can accurately separate components, avoid damage to surrounding battery cells, modules or electrical connection components caused by violent disassembly, and ensure the overall structural stability and safety of the battery system; (3) Aluminum chips and welding slag are cleaned up in time to prevent residual metal debris from causing internal short circuits or poor contact; grinding eliminates sharp edges and burrs, further improving the safety of the rework process and reducing the risk of short circuits and safety hazards.

[0020] Preferably, as an improvement, step S340 includes the following steps: Step S341: Remove the FPC or other components with poor welding; Step S342: repairing the pole hole; Step S343: using a grinding gun to grind the pole; Step S344: Clean the box and the poles.

[0021] Beneficial effects: Step S341 safely removes the faulty or poorly welded FPC (flexible circuit board) or other connecting components from the module, ensuring that subsequent repair and assembly are not affected; Step S342 repairs the damage to the pole hole caused by welding, drilling or rework operations, restores its structural integrity and assembly accuracy, and provides a reliable basis for subsequent welding or connection; Step S343 uses a grinding gun to finely grind the pole surface to remove the oxide layer, burrs and residual solder joints, ensure that the pole surface is flat and clean, and improve the conductive performance and assembly consistency; Step S344: Thoroughly remove grinding residues, metal debris and other foreign matter from the box and pole to ensure the cleanliness of the working area and prevent pollution from affecting electrical connections or causing short circuit risks.

[0022] Preferably, as an improvement, the polishing effect and the pole height need to be checked in real time during the pole polishing process; wherein the surface flatness of the polished pole is 0-0.5 mm; and the pole height is greater than the pole insulation sleeve height.

[0023] Beneficial effects: Setting the pole surface flatness can significantly reduce contact surface resistance, improve conductivity, and avoid local overheating or energy loss due to poor contact; the pole height requirement can ensure that when assembling copper buses or other connectors, metal parts will not directly contact the insulating sleeve or shell, thereby effectively preventing safety hazards such as short circuits and leakage.

[0024] Preferably, as an improvement, step S420 includes the following steps: Step S421: removing the binding belt, using an angle grinder to cut off the binding belt of the fixed module; Step S422: Remove the module end plate, insert a wedge plate into the gap between the battery cell and the end plate, and then use a hammer to gently tap the wedge plate, gradually applying force to separate the end plate from the battery cell; Step S423: Remove the module cells by inserting a wedge plate into the gap between adjacent cells and then gently tapping the wedge plate with a hammer until the cells are separated; Step S424: removing the heating film; Step S425: cleaning foreign matter.

[0025] Beneficial effect: Steps S421 to S425, through Pack protection, insulation treatment and standardized disassembly process, not only the faulty part is effectively removed, but also short circuit, battery cell damage and personnel operation risks are prevented, ensuring the safety and controllability of the entire repair process; using general tools such as wedge plates + hammers for non-destructive disassembly, the operation is simple and efficient.

[0026] Preferably, as an improvement, step S440 further includes the following steps: Step S441: Pack the package for glue removal protection, and wrap and cover the area where glue removal is required with insulating tape; Step S442: Remove glue from the bottom surface of the box body. First, perform low-speed milling on the bottom surface of the box body with a feed depth of 0.2mm-0.5mm. After the milling is completed, switch to a grinding gun to grind and clean the residual glue and remove glue chips. Step S443: Remove the glue on the bottom side of the box body. First, perform low-speed milling on the glue on the bottom side of the box body until the remaining thickness of the glue surface is 1.0mm-1.2mm. Then, switch to the grinding gun to grind and clean the residual glue until the remaining thickness of the glue surface is 0.8mm-1.0mm. Then stop grinding and clean the glue scraps. Step S444: Remove the insulating tape.

[0027] Beneficial effect: Through the setting of steps S441 to S444, the effectiveness and safety of glue removal are ensured.

[0028] Preferably, as an improvement, step S400 further includes the following steps: Step S450: Gluing the bottom of the box; Step S460: The module is put into the box.

[0029] Preferably, as an improvement, it further comprises: Step S500: After the accessory removal path is completed, CCS / bar welding is performed; Step S600: Assembling, which includes online material inspection, replacement of new FPC or other components, copper busbar installation, completion of battery pack assembly and assembly torque recording; Step S700: Perform testing and verification, including OQC full inspection, insulation withstand voltage test, EOL test and charge and discharge test.

[0030] Beneficial Effects: Steps S500 to S700 form a closed-loop system of "repair → assembly → verification" in the power battery repair process. This not only improves repair efficiency and quality, but also enhances the professional level of power battery maintenance from multiple dimensions such as safety, consistency, and traceability. It is a key guarantee for achieving efficient, high-quality, and high-reliability repairs.

[0031] The beneficial effects of this solution are as follows: (1) This solution realizes that the demolition area is controllable, the safety risks of the demolition process are controllable, foreign matter in the demolition process is controllable, and the demolition process is time-saving and labor-saving, and the demolition area will not damage other parts.

[0032] (2) This solution significantly shortens the rework cycle by optimizing more than 100 processes from step 100 to step 700 in parallel. The welding rework time is compressed from 1 hour to 20 minutes, and the glue rework time is reduced from several hours to 10 minutes. At the same time, the rework quality and yield rate are greatly improved: the welding yield rate is increased from 30% to 99%, and the glue yield rate is increased from 40% to 99%. In addition, this solution enhances connection reliability, effectively guarantees assembly accuracy and process consistency, reduces the risks of short circuits and poor contact, and comprehensively improves rework efficiency and product stability.

[0033] (3) This solution adopts a purely physical repair method that does not rely on chemical reagents, which not only reduces pollution to the environment but also reduces the cost of repair.

[0034] (4) This solution cleverly combines machining precision with flexible surface treatment technology through the innovative design of "drilling machine + grinding gun" in steps 100-700. The high-precision cutting capability of the drilling machine is used to precisely remove welding defects and cured glue, while the flexible operation characteristics of the grinding gun are used to finely treat the remaining welding surface and cured glue surface. While taking into account the internal structural safety of the power battery and the protection of sensitive materials, it achieves a multi-dimensional breakthrough in rework efficiency, cost control, quality assurance, and process standardization. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention provides a flowchart of a method for repairing a power battery. DETAILED DESCRIPTION

[0036] The embodiment is basically as follows Figure 1Shown: A method for repairing a power battery, comprising: Step S100: confirm the repair content; Repair details include the repair type and repair location. Repair types include soldering repair and glue repair. Soldering repair includes FPC repair and defective soldering repair. Glue repair includes heater film repair and defective battery cell repair. The repair location refers to the specific area inside the battery pack that requires repair.

[0037] The specific steps include: Step S110: performing fault detection on the returned battery and obtaining the fault detection result; Specifically, fault information is collected and visual inspections are performed on returned batteries to obtain fault detection results. Fault information collection involves reading fault codes from the battery management system (BMS) to troubleshoot problems such as cell overvoltage / undervoltage, abnormal temperatures, and insulation failures. Charge and discharge cycle data is also analyzed to determine whether the battery has experienced performance degradation (e.g., a capacity drop >20%) due to long-term use. Furthermore, feedback records are used to identify the direct cause of the battery return (e.g., "sudden drop in battery life," "abnormal charging," "alarm prompts," etc.).

[0038] The appearance inspection includes both an overall inspection and a module / cell-level inspection. The overall inspection checks the battery pack casing for deformation, damage, leakage, or rust. High-voltage and low-voltage connectors are also inspected for oxidation or looseness. The module / cell-level inspection involves observing the battery cell's exterior to check for bulging, leakage, or terminal corrosion. It also examines the busbars and sampling cables (FPCs) within the module for breakage or corrosion.

[0039] Step S120: confirming the repair type and repair location of the repaired battery according to the fault detection result; Specifically, based on the fault detection results, a comprehensive analysis of the fault phenomenon is conducted to determine the repair type and repair location of the returned battery. If an FPC circuit is detected to be blocked, a solder joint has a cold solder joint, a desoldering phenomenon, or a short circuit or open circuit is detected at the weld, it is determined to be a welding repair. If the heating film is found to be cracked, detached, or heating unevenly, or if the battery cell is abnormal, leaking, damaged in appearance, deformed in the shell, or a foreign object in the glue punctures the battery cell, and the repair requires the removal of the battery cell, it is determined to be a glue repair.

[0040] Welding rework includes FPC rework and defective welding rework.

[0041] FPC repair: When the fault is concentrated on the FPC (flexible printed circuit), such as FPC burnout, broken circuits on the FPC surface, blocked vias, or problems with the solder joints connecting the FPC to the battery cell or module, affecting battery data collection and signal transmission functions, it is determined to be an FPC repair. In this case, further inspection of the specific location of the FPC damage is required to mark the exact location of the broken circuit or poor solder joint.

[0042] Welding Defect Repair: If the fault occurs in the cell connector soldering, module busbar soldering, or other areas, and is manifested by insufficient solder strength, excessive solder resistance, or uneven solder joint surfaces, it is considered a welding defect repair. Through visual inspection, solder strength testing, and resistance measurement, the location of the defective solder joint, such as the connecting solder joints between certain cells or the busbar solder joints between modules, can be precisely located. Glue repair includes defective heating film repair and defective battery cell repair.

[0043] Defective heating film repair: If abnormal battery heating function is detected, and inspection reveals separation or bubbles between the heating film and the battery surface, or poor contact of the conductive circuit within the heating film due to aging or cracking of the glue, or abnormalities such as heating film damage or heating film circuit disconnection, the heating film is determined to be defective and needs repair. Carefully inspect all parts of the heating film and mark the specific locations of debonding, cracking, and poor circuit contact. Defective Cell Repair: When a cell exhibits abnormalities, leaks, shakes, is damaged, has a deformed casing, or has foreign matter punctured the cell, inspection reveals failure of the sealant between the cell casing and the terminal, or loosening of the cell securing glue. This is considered a defective cell repair. The battery module is disassembled to identify the specific cell with the problem and the location of the glue failure, such as the cell top seal or the securing point between the cell and the module bracket.

[0044] Step S200: confirming the accessory removal path and repair parameters according to the repair content, the accessory removal path includes a welding repair path and a glue repair path, and the repair parameters include welding repair parameters and glue repair parameters; Specifically, the accessory removal path and repair parameters are determined based on the repair type and repair location. The soldering repair path is the path for removing accessories connected by soldering, and the glue repair path is the path for removing accessories bonded by glue.

[0045] Rework parameters include drill bit model, rotation speed and feed depth. Rework parameters are divided into welding rework parameters and glue rework parameters. The most suitable drill bit model, rotation speed and feed depth can be dynamically selected according to different situations, thereby significantly improving the demolition efficiency and avoiding slow processing or repetitive operations due to parameter mismatch. At the same time, it can achieve controllable demolition area and controllable safety risks of the demolition process, effectively avoiding damage to the pole body, battery cell or other surrounding structures, reducing the risks of short circuit, structural deformation, etc., and ensuring the safety of the rework process.

[0046] Step S300: performing a removal operation of the welding repair path; which includes the following steps: It includes the following steps: Step S310: Remove the output copper busbar and the module series copper busbar in sequence, cut off the electrical path between the modules, and separate the single module or part of the module to be repaired from the overall circuit; The output copper busbar and the module series copper busbar (collectively referred to as the "jumper copper busbar"). Specifically, according to the single torque standard for the line, select a matching torque gun. Then, use the torque gun to remove the jumper copper busbar to cut the electrical path between the modules and isolate the single module or part of the module to be repaired from the overall circuit. During the disassembly process, be careful to control the force to avoid deformation or damage to the copper busbar due to improper operation. After disassembly, the disassembled copper busbars should be uniformly labeled and placed, clearly marked with the corresponding battery pack number to prevent damage and material mixing, and facilitate subsequent use.

[0047] Step S320: Using insulating tape to protect the entire module to be repaired, then hoisting the module to be repaired to the drilling machine, and defining the position of the module to be repaired by using a positioning fixture; Specifically, after the output copper busbar and the module series copper busbar are removed, the module to be repaired is wrapped with insulating tape for protection, and a blue pen is used to mark the points that need to be processed, that is, the drilling and milling points. For example, taking "FPC rework" as an example, the FPC processing surface is completely covered and extended to the edge of the box, and a blue pen is used to mark the points that need to be processed. In this embodiment, the whole package protection treatment must be completed before all drilling and milling operations to ensure the safety of the drilling and milling process and the stability of the operating environment, and to prevent aluminum chips generated by drilling and milling from entering the module to be repaired. And in this embodiment, the whole package protection treatment is not limited to the use of insulating tape for wrapping protection, and other suitable protective materials or methods can also be selected according to actual needs to meet different application scenarios and process requirements.

[0048] Step S330: Based on the welding repair parameters, the disassembly operation is performed using a drill press and a grinding gun on the same set of equipment. When disassembling the problematic battery, the drilling and milling of the drill press and the grinding gun are used to collaboratively remove the terminal tabs, remove the CCS or tabs, and clean the aluminum shavings to expose the specific location to be repaired. It specifically includes the following steps: Step S331: First, drill and mill the pole tab at a high speed until the remaining thickness of the drilled and milled surface is 1mm-2mm. Then, drill and mill at a slow speed until a clear gap appears on the drilled and milled surface. At this point, stop drilling and milling, use a grinding gun to remove residual welding slag and metal burrs, and clean up the generated aluminum chips. In this embodiment, the drilling machine used is composed of a workbench, a drill bit clamping device and a control system.

[0049] The workbench is used to place and support the workpiece to be repaired. It is also equipped with several fixtures that can firmly clamp the workpiece to be processed from the left and right sides, enabling rapid clamping of the workpiece and providing a basis for subsequent precise processing.

[0050] The drill bit clamping device is used to install and fix the drill bit. It adopts a self-tightening three-jaw drill chuck (or Morse taper interface), which can adapt to drill bits of different diameters and is easy to install and disassemble.

[0051] The control system includes various control components and a digital display panel for starting, stopping, and adjusting the drilling machine's speed. These components include a locking button, fine-adjustment handle, unlocking button, position control board, drill crank, drill speed adjustment, and drill feed rate. The locking button secures the spindle position; the unlocking button releases the mechanical spindle lock. The unlocking button and locking button are used in conjunction. Before changing the drill bit, press the locking button to secure the spindle to prevent accidental rotation. After changing the drill bit, press the unlocking button to restore free spindle rotation. The fine-adjustment handle precisely controls the vertical feed rate of the drill bit to ensure machining accuracy. The position control board accurately controls and monitors key machining parameters and positioning data. The drill crank locks and releases the drill bit. The drill speed adjustment adjusts the drill speed to suit different machining requirements. The drill feed rate adjustment uses a mechanical dial or digital display (DRO) to set the feed depth, preventing through-hole drilling and ensuring machining safety and quality. The digital display panel features a reset keypad for resetting the currently displayed value or parameter to zero, allowing for quick reference position setting. For example, when the drill bit reaches the surface of the blade, pressing the reset keypad will use the blade surface as the reference position, allowing subsequent feed depth calculations to restart from zero, facilitating precise control of machining dimensions.

[0052] Specifically, drilling and milling the tab refers to using a drill press to drill and mill the tab's weld area. In this embodiment, the tab's weld ring is used as an example of the weld area. The tab's weld ring refers to the annular weld area in the battery module that connects the tab to the pole. Drilling and milling the tab's weld ring can separate the weld between the tab and the pole.

[0053] The entire package of protectively treated modules to be repaired is hoisted onto the drill press's workbench using a lifting device. Clamps are then used to securely clamp the modules from both sides, enabling rapid workpiece assembly and ensuring precise machining. This prevents offset or displacement during machining. Next, a ceramic knife is used to remove the insulating tape marking the drilling and milling points. The opening in the tape is larger than the diameter of the blade weld ring, fully exposing the blade weld ring.

[0054] Afterwards, operate the drilling machine to drill and mill the corresponding area: First, select the appropriate drill bit on the drilling machine. Next, align the drill bit with the center of the bar weld ring and slowly lower the drill bit to the surface of the bar weld ring; operate the fine-adjustment handle to gently rotate; when aluminum chips are observed, the fine-adjustment handle immediately stops turning, and click the "zero" keyboard on the digital display panel to reset the currently displayed value or parameter to zero. At this time, the surface of the bar weld ring is the reference position. Next, set the drill bit's rotation speed and feed depth by adjusting the drill bit speed and drill bit feed amount. Afterwards, operate the fine-adjustment handle on the drilling machine to perform fast drilling and slow drilling and milling in sequence. Taking a 2mm thick bar welding ring as an example, the fast milling feed depth is controlled at 1.6mm, the rotation speed is 200r / min, and the fast milling downward feed speed is: 0.04mm / s; if the bar welding ring thickness is 1.5mm, the fast milling feed depth is adjusted to 1.2mm. When the remaining thickness of the drilling and milling surface is 1mm-2mm, the fast milling is completed and the operation is stopped. The aluminum chips attached to the drill bit are promptly removed, and a vacuum cleaner is used to remove the residual aluminum chips around to prevent secondary contamination or damage. Subsequently, the fine-tuning handle is operated again to enter the slow drilling and milling stage. The slow drilling and milling feed depth is 2mm-4mm, the rotation speed is 80r / min, and the slow milling downward feed speed is 0.02mm / s. Precise control is performed according to the scale on the digital display panel. When the drilling and milling reaches the set depth, the operation is stopped until a clear gap appears on the drilling and milling surface. At this time, the drilling and milling is stopped and a grinding gun is used to remove residual welding slag and metal burrs. The welding point is clean, flat and smooth, which is convenient for subsequent reconnection and installation. Finally, the generated aluminum chips are cleaned. In this embodiment, the remaining thickness tolerance of the workpiece after drilling and milling is ±0.1 mm.

[0055] In this embodiment, during the entire drilling and milling process, special attention should be paid to the following two points: (1) When the milling depth reaches 1.5mm, the aluminum chips on the drill bit must be thoroughly cleaned to avoid damage to the pole due to accumulation of aluminum chips; (2) When entering the slow milling stage, the fine-tuning handle must be turned slowly and evenly to ensure processing accuracy and safety.

[0056] (3) Finally, the total drilling and milling depth of the bar welding ring is 1.8-2.3mm, which can effectively separate the bar from the pole without causing damage to the pole body, thereby ensuring the quality of repair and operational safety.

[0057] Step S332: Repeat step S331 to remove the CCS or the bar by drilling and milling, and clean the aluminum chips to expose the specific location to be repaired; Specifically, step S331 is repeated until the CCS (flexible circuit collection board) or remaining pieces in the battery pack are removed, exposing the FPC or welding points that need to be repaired; Step S340: performing a whole-package protective treatment on the unrepaired parts, and obtaining grinding data, repairing the pole hole and grinding the pole according to the grinding data, cleaning the debris, and completing the removal of the welding repair path; It includes the following steps: Step S341: Remove the FPC or other components with poor welding; Specifically, when removing an FPC (which is part of FPC rework), the operator grasps one end of the FPC and slowly peels it off the module along its length, avoiding damage caused by rough pulling. During the removal process, special care must be taken to prevent the aluminum tabs from touching each other to avoid short circuits. If the FPC is tightly adhered and difficult to peel off, use needle-nose pliers to assist in peeling, but be careful to avoid direct contact with the aluminum tabs to prevent the risk of short circuits. After disassembly, use a vacuum cleaner to thoroughly clean the module surface, thoroughly removing any remaining aluminum chips and debris, and confirming that there are no aluminum chips on the module surface to ensure the safety and reliability of the rework process.

[0058] When removing other poorly welded parts (which belong to poor welding repair), since the other poorly welded parts are fixed with bolts, during the removal process, the operator uses a tightening gun to remove the bolts one by one to complete the separation and replacement of the parts.

[0059] Step S342: repairing the pole hole; Pole hole repair refers to the process of repairing or reprocessing the damaged or failed pole holes of power battery poles. Specifically, except for the pole grinding area, all areas are covered with insulating tape, and the tape is extended to the edge of the box to prevent metal debris from being generated during grinding or drilling, which may cause short circuits. When the original pole hole is blurred due to deformation or residual foreign matter (such as colloids, metal chips) (i.e., the pole hole is not obvious), use a 2.5mm diameter drill bit with a feed depth of 0.5-1mm and a rotation speed of 200r / min. Lightly drill at the center of the estimated hole position to remove the metal abnormality covering the pole hole.

[0060] During operation, keep the drill bit perpendicular to the pole surface to avoid deviation and ensure the accuracy of the subsequent repair hole position.

[0061] Step S343: using a grinding gun to grind the pole; Specifically, use a grinding gun to polish the pole surface to remove oxide layers, burrs, and other surface defects to ensure a smooth and reliable contact surface. During the polishing process, the polishing effect and pole height should be checked in real time. The polished pole surface flatness should be 0-0.5mm to ensure good electrical connection performance. The pole height should be greater than the height of the pole insulation sleeve to prevent poor contact or insulation failure due to insufficient height after assembly.

[0062] After completing the grinding operation of all poles, first use a vacuum cleaner to remove the metal dust and debris generated by grinding. Then, remove the protective tape to avoid residual colloid contamination. Finally, use a dust-free cloth soaked in alcohol to thoroughly wipe the surface of the pole to ensure that there is no dirt or foreign matter on the surface and keep it clean.

[0063] Step S344: Clean the box and the poles; Specifically, use a vacuum cleaner to thoroughly clean the inside of the battery box and the poles, and completely remove residual debris, oxides or stains generated during the drilling and milling process to ensure that the surface of the welding area is clean and flat without any foreign matter attached, so as to improve the reliability of subsequent welding or assembly processes and ensure the safe and stable operation of the battery system.

[0064] Step S400: performing accessory disassembly of the glue rework path; It includes the following steps: Step S410: dismantling the basic accessories around the power battery to expose the module; Specifically, execute steps S310 to S330, remove the output copper busbar, the module series copper busbar, drill, mill and grind to remove the pole tabs, remove the CCS or tabs, so that the internal battery module is completely exposed to facilitate subsequent repair operations.

[0065] Step S420: dismantling the modules and separating the modules with glue bonding problems; That is, disassemble the modules in the battery pack and separate the module where the heating film or battery cell that needs to be repaired is located.

[0066] Specifically, the following steps are included Step S421: removing the strapping tape; Specifically, an angle grinder is used to cut the binding straps that hold the module in place. During operation, the operator holds the corneal machine tightly with both hands to ensure stable control of the equipment and prevent the tool from falling due to improper operation, thereby avoiding possible safety accidents.

[0067] Step S422: removing the module end plate; Specifically, insert the wedge into the gap between the battery cell and the end plate. Then, gently tap the wedge with a hammer, gradually applying force to separate the end plate from the battery cell until it is completely detached and removed. During this operation, care should be taken to avoid damaging adjacent modules and prevent safety hazards such as short circuits, ensuring a safe and controllable operation.

[0068] Step S423: removing the module battery cells; Specifically, when removing battery cells, a wedge-shaped plate is inserted into the gap between adjacent battery cells, and then a hammer is used to gently tap the wedge-shaped plate to gradually separate the battery cells until the battery cells are peeled off, thereby separating the battery cells that need to be repaired.

[0069] Step S424: removing the heating film; Specifically, when removing the heating film, since the heating film is usually pasted on the surface of the module, the module can only be removed and replaced with a new module with a normal heating film pasted on it. However, whether the heating film or the module battery is damaged, during the module removal process, only the module is removed, and the heating film will be damaged during the removal process, and it is impossible to remove the heating film alone intact. Therefore, when removing the heating film, there are two ways: the first is to slowly tear off the heating film along the edge before removing the module battery; the second is that during the removal of the module battery, the operator removes the battery cells one by one in the order of the battery cells, and then removes the heating film.

[0070] Safety precautions: 1. Avoid affecting surrounding undisassembled modules during operation to prevent safety accidents such as short circuits caused by collisions or scratches; 2. The removed battery cells should be placed neatly, and the positive and negative poles of each battery cell should be wrapped and shielded with insulating tape to prevent short circuits caused by exposed electrodes, further ensuring the safety of the working environment.

[0071] Step S425: cleaning foreign matter; Specifically, use a vacuum cleaner to thoroughly clean the inside of the box to remove residual debris, dust and other foreign matter, ensure that the environment inside the box is clean and tidy, and provide good working conditions for subsequent assembly or repair work.

[0072] Step S430: Using insulating tape to protect the non-repaired parts; Step S440: Based on the glue repair parameters, a disassembly operation is performed using a drill press and a grinder on the same set of equipment. When disassembling the problematic battery, the drill press and the grinder are used to collaboratively remove the glue on the bottom surface and the sides of the box, completing the removal of the glue repair path. Specifically, remove the residual adhesive at the bottom of the box to facilitate re-fixing the module when replacing the heating film or battery cell later.

[0073] It includes the following steps: Step S441: removing glue from the pack; Specifically, the area where glue needs to be removed is wrapped and covered with insulating tape to prevent the spread of debris and dust generated during the subsequent glue removal process, which could cause short circuits or damage other components. This improves operational safety, reduces secondary contamination, and ensures controllability and cleanliness during the repair process.

[0074] Step S442: Remove glue from the bottom surface of the box body. First, perform low-speed milling on the bottom surface of the box body with a feed depth of 0.2mm-0.5mm. After the milling is completed, switch to a grinding gun to grind and clean the residual glue and remove glue chips. Specifically, after completing the protective measures, begin removing the glue from the bottom surface of the battery case. This involves initial treatment of the glue on the bottom surface using low-speed milling. The drill press rotates at a speed of 100 r / min and a feed depth of 0.2mm-0.5mm. Once milling is complete, switch to a grinding gun to clean any remaining glue. When removing the entire bottom glue layer, only a thin layer needs to be removed; complete removal is not necessary. Typically, the total thickness of the bottom glue removed is 0.2mm-0.5mm, which can vary depending on actual conditions, but it must be ensured that the surrounding modules and the case structure are not damaged during the removal process.

[0075] In addition, when removing the glue from the bottom, the drill bit's downward pressure height must be flexibly adjusted according to the glue thickness to avoid damaging the metal structure at the bottom of the box due to excessive feeding. The equipment must be operated smoothly during the glue cleaning process to avoid shaking or accidental touch to prevent milling damage to surrounding undisassembled modules or affect other components. At the same time, after completing the glue cleaning of a small area, the generated glue and metal debris should be immediately cleaned with a vacuum cleaner to prevent accumulation that affects subsequent operations or causes safety hazards.

[0076] Step S443: Remove the glue on the bottom side of the box body. First, perform low-speed milling on the glue on the bottom side of the box body until the remaining thickness of the glue surface is 1.0mm-1.2mm. Then, switch to the grinding gun to grind and clean the residual glue until the remaining thickness of the glue surface is 0.8mm-1.0mm. Then stop grinding and clean the glue scraps. Specifically, after completing the glue removal on the bottom surface, continue to remove the glue on the bottom side of the box. First, perform low-speed milling on the glue on the bottom side of the box. The rotation speed of the drill press is 100r / min, and the feed depth is 2-3mm. When the remaining thickness of the glue surface is 1.0mm-1.2mm, switch to the grinding gun to grind and clean the residual glue until the remaining thickness of the glue surface is 0.8mm-1.0mm. Stop grinding and clean the glue chips. When removing glue, only a thin layer needs to be removed, and all of it does not need to be removed. Remove the glue from the bottom side of the box. Normally, the thickness of the side glue removal is controlled at 2-4mm, which can vary according to actual conditions, but it must be ensured that the surrounding modules and box structure are not damaged during the removal process.

[0077] When milling the glue on the bottom, pay attention to the drilling depth of the drill bit. Reasonably set the cutting depth of the drill bit according to the thickness of the side glue to avoid damage to the box body caused by excessive milling. In addition, the status of the surrounding modules should be observed at all times during the glue cleaning process to prevent accidental contact or damage due to vibration or excessive milling force. At the same time, after each glue cleaning is completed, the remaining debris should be cleaned immediately to ensure that the working area is clean for subsequent inspection and assembly.

[0078] Step S444: removing the insulating tape; Specifically, after removing the glue, peel the tape slowly and evenly to avoid residual glue contamination or damage to the protected surface caused by rapid tearing. If any residual tape residue is found, it should be wiped clean with a special cleaner or a dust-free cloth to ensure that the covered area is clean and free of foreign matter.

[0079] Step S450: Gluing the bottom of the box; Specifically, after removing the adhesive from the bottom of the cabinet, removing faulty components like the old heating film or battery cells, and cleaning, the new adhesive application to the bottom of the cabinet begins. During this process, the components that need to be replaced, such as the new heating film or battery cells, are first replaced based on the repair requirements, and their correct installation position is confirmed. The new adhesive is then evenly applied to the bottom of the cabinet to provide support and insulation for module installation.

[0080] Step S460: Modules are put into boxes; Specifically, use a sling to reinstall the processed module (after replacing the heating film or battery cell) into the battery box, and ensure that it is positioned accurately and firmly fixed.

[0081] Step S500: After the accessory removal path is completed, CCS / bar welding is performed; Specifically, thoroughly clean the welding area and use a dust-free cloth dipped in alcohol to remove any dust, oxide layer, or residual flux that may exist on the surface and surrounding areas of the pole. Next, check whether the CCS and the bar to be welded are intact, and confirm that their models and specifications are consistent with the original design. Finally, accurately place the CCS or bar on the pole according to the assembly drawing requirements, and weld according to the welding process requirements.

[0082] Step S600: Assembling, which includes online material inspection, replacement of new FPC or other components, copper busbar installation, completion of battery pack assembly and assembly torque recording; Specifically, after the rework is completed, the normal process will be followed for reassembly and testing; the assembly includes online material inspection, replacement of new FPC or other components, copper busbar installation, completion of battery packaging assembly and assembly torque recording.

[0083] (1) Inspection of online materials: Confirm the appearance and specifications of all parts returned for repair and replacement (such as FPC, CCS, panels, insulation materials, etc.) to ensure that they are free of damage, pollution, and meet technical requirements. At the same time, record the batch number of all materials and the information of the parts returned for repair and replacement to achieve traceability of the entire process; (2) Replace the FPC or other components with a new one: Take "FPC" as an example. When replacing the FPC with a new one for welding, first fix one end of the FPC, adjust the alignment, and then weld the other end to avoid misalignment.

[0084] (3) Copper busbar installation: Before installing the copper busbar, make sure that the contact surface with the pole is flat, apply conductive paste as needed, and tighten according to the torque specification; then check the insulation resistance between the copper busbar and the shell to ensure good electrical isolation.

[0085] (4) Complete the battery packaging: install the top cover and sealing ring, test the overall sealing performance, and paste the repair label in the designated location, indicating the repair content, date and operator.

[0086] (5) Assembly torque record: When installing key fasteners such as copper busbar connecting bolts, module fixing screws, cover screws, etc., the specified torque must be applied strictly in accordance with the process requirements, and the torque data of each fastening point must be recorded and archived to facilitate subsequent quality tracking and analysis; Step S700: Testing and verification, which includes OQC full inspection, insulation withstand voltage test, EOL test and charge and discharge test; Specifically, in order to ensure the stable, safe and reliable performance of the battery pack after repair, a series of systematic tests and verifications are required, mainly including OQC full inspection, insulation withstand voltage, EOL test and charge and discharge test.

[0087] OQC full inspection: After assembly, the entire package is 100% inspected, including: a. Post-soldering appearance cleaning and inspection: Use a dust-free cloth dipped in alcohol or a special cleaner to remove solder residue, flux, and metal debris; the solder joints should be smooth, free of burrs, cold solder joints, or solder balls; the FPC should be free of creases and damage; the insulating tape should be flat and not warped; b. Structural and electrical function testing: Verify whether all components are assembled in place and whether the electrical connections are normal; Insulation withstand voltage test: Voltage is applied between the positive and negative poles of the battery and the shell for testing. No breakdown or flashover should occur during the test.

[0088] EOL test: including voltage consistency detection, BMS function verification: communication, SOC calibration, fault code reading is normal.

[0089] Charge and discharge test: Perform a complete charge and discharge cycle, monitor the voltage and temperature curves to see if they are normal, and record capacity attenuation.

[0090] After testing, this solution adopts a purely mechanical rework method of "drilling machine + grinding gun", which significantly improves rework efficiency, rework quality and cost. In terms of welding rework, compared with the traditional manual stripping of 1 hour, this solution shortens the single rework time to 20 minutes; the welding yield rate is increased from 30% to 99%; in terms of gluing rework, compared with the traditional chemical immersion of at least 4 hours, this solution shortens the rework time to 10 minutes; the glue yield rate is increased from 40% to 99%. In addition, the flatness and levelness after stripping by "drilling machine + grinding gun" of this solution cannot be achieved by traditional rework methods. This solution effectively reduces the material cost in the rework process, while having higher process stability and repeatability, and the rework pass rate is significantly improved to more than 99%.

[0091] The current repair process for power batteries is fraught with problems. Typically, a localized repair is performed after a problem is discovered, meaning the problem is identified first and then addressed. Problems often arise unexpectedly. In most cases, when a power battery fails to operate properly, performs below performance standards, or fails to pass test indicators, it is identified as a "problem battery" and requires repair. However, the exact cause of the problem is unclear, and the only option is to repair and investigate the cause.

[0092] That is, the current repair means "find the problem first - solve the cause - repair successfully". Among them, for common cause of the problem, a routine is needed to troubleshoot the problem. Currently, there are two common troubleshooting steps: the first type of welding detection: performance testing and position detection of components and parts formed by welding in battery modules or battery cells to determine whether there are abnormalities; the second type of glue detection: performance testing and position detection of components and parts formed by glue in battery modules or battery cells to determine whether there are abnormalities. Based on existing experience and corresponding existing equipment and components, following these two troubleshooting steps, most of the causes of the problem can be found, which can meet the repair needs of most problem batteries.

[0093] However, with the increase in battery capacity and the diversification of battery technology, new battery structures and material systems are constantly being introduced. The causes of problem batteries are becoming increasingly complex, and troubleshooting them is becoming increasingly time-consuming, which not only reduces repair efficiency but also significantly increases repair costs. This solution breaks away from the traditional framework and proposes a new battery repair method that can systematically troubleshoot problem batteries regardless of their cause, achieving the goals of efficient, high-quality, and low-cost repairs.

[0094] In existing technology, technicians are limited by the traditional mindset of "welding rework uses mechanical tools, glue rework uses chemical reagents." This is because traditionally, technicians believe that welds are physical connections requiring mechanical separation, while glue bonds are chemical and can only be broken with chemical reagents. These two rework methods have completely different, independent, and irreplaceable repair mechanisms. When faced with rework problems, due to the distinct repair mechanisms of welding and gluing, technicians instinctively seek solutions within their respective fields and avoid easily crossing boundaries. For example, they wouldn't consider applying a drill press to glue rework (as they don't traditionally cut objects). The creative combination of a drill press and a grinder, two seemingly unrelated pieces of equipment, for welding and glue rework defies conventional wisdom. Furthermore, drill presses and grinders are typically used primarily in machining and manufacturing, not rework. Expanding their capabilities to rework scenarios requires a deep understanding of equipment performance and process parameters, as well as extensive experimentation and optimization, something that simply can't be achieved through conventional thinking or simple experimentation. This solution breaks the technical preconception that solder rework and glue rework must utilize different treatment methods. Instead, it innovatively proposes a combination of drilling and milling with a drill press and polishing with a grinder. By properly selecting tools, process parameters, and protective treatments, physical processing can effectively handle both solder and glue repairs. This integrated approach not only addresses the inefficiencies of traditional methods but also improves repair quality. For solder rework, drilling and milling precisely remove solder and the connecting layer from the weld by adjusting the drill press's speed, drill bit type, and feed parameters. For solder joints of varying sizes and materials, the appropriate degree of milling and polishing can be selected to achieve efficient solder stripping, avoiding the excessive damage to surrounding components that can occur with traditional mechanical stripping methods. For glue rework, a drill press can quickly remove most of the glue layer from the surface, followed by fine polishing with a grinder until the residual glue is essentially removed. Compared with soaking in a degumming agent, this physical method does not require waiting for chemical reactions and can complete the glue removal work in a short time. It does not introduce chemical reagents, avoids the risk of chemical corrosion to the material, and ensures the original performance of the material.

[0095] In addition, this solution achieves controllable demolition area, controllable safety risks during the demolition process, controllable foreign matter during the demolition process, and the demolition process is time-saving and labor-saving, and the demolition area will not damage other components.

[0096] Specifically, this solution targets the locations connected by welding or gluing, and the drilling machine performs drilling and milling on the target area. The drilling and milling speed and feed depth can be flexibly adjusted according to the actual connection structure and material thickness to ensure the effective separation of the connected components. After drilling and milling, a grinding gun is used to finely grind the remaining welding slag and metal burrs to ensure the effective separation of the connected components, as well as to make the surface smooth and flat, eliminating the safety hazards caused by sharp edges. In addition, during the entire rework process, insulating tape must be used to cover and protect the unrepaired areas to prevent accidental damage to other battery components. A vacuum cleaner is also used to remove metal debris and foreign matter to keep the working environment clean and tidy to avoid short circuits or other quality risks caused by foreign matter.

[0097] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A method for repairing a power battery, characterized in that: The following steps are involved: Step S100: confirm the repair content; Step S200: confirming an accessory removal path and repair parameters according to the repair content, wherein the accessory removal path includes a welding repair path and a glue repair path, and the repair parameters include welding repair parameters and glue repair parameters; Step S300: performing the removal operation of the welding repair path, including the following steps: Step S310: Remove the output copper busbar and the module series copper busbar in sequence, cut off the electrical path between the modules, and separate the single module or part of the module to be repaired from the overall circuit; Step S320: Using insulating tape to protect the entire module to be repaired, then hoisting the module to be repaired to the drilling machine, and defining the position of the module to be repaired by using a positioning fixture; Step S330: Based on the welding repair parameters, the disassembly operation is performed using a drill press and a grinding gun on the same set of equipment. When disassembling the problematic battery, the drilling and milling of the drill press and the grinding gun are used to collaboratively remove the terminal tabs, remove the CCS or tabs, and clean the aluminum shavings to expose the specific location to be repaired. Step S340: Performing a whole-package protective treatment on the unrepaired parts, obtaining grinding data, repairing the pole hole and grinding the pole according to the grinding data, and cleaning the debris to complete the removal of the welding repair path; Step S400: performing accessory disassembly of the glue rework path; comprising the following steps: Step S410: dismantling the basic accessories around the power battery to expose the module; Step S420: dismantling the modules and separating the modules with glue bonding problems; Step S430: Using insulating tape to protect the non-repaired parts; Step S440: According to the glue repair parameters, use the drill press and grinder on the same set of equipment to perform disassembly operations; when performing the disassembly operation of the problem battery, the drill press and the grinder are used to collaboratively remove the glue on the bottom surface of the box and the glue on the bottom side of the box to complete the removal of the glue repair path.

2. A power battery repair method according to claim 1, characterized in that: The rework content includes the rework type and rework location; the rework type includes welding rework and glue rework; the welding rework includes FPC rework and welding defect rework, and the glue rework includes heating film defect rework and battery cell defect rework; the rework location refers to the specific area inside the battery pack that requires rework operation.

3. A power battery repair method according to claim 2, characterized in that: Step S100 includes the following steps: Step S110: performing fault detection on the returned battery and obtaining the fault detection result; Step S120: confirming the repair type and repair location of the battery to be repaired according to the fault detection result.

4. The power battery repair method according to claim 1, characterized in that: Step S330 includes the following steps: Step S331: First, drill and mill the pole tab at a high speed until the remaining thickness of the drilled and milled surface is 1mm-2mm. Then, drill and mill at a slow speed until a clear gap appears on the drilled and milled surface. At this point, stop drilling and milling, use a grinding gun to remove residual welding slag and metal burrs, and clean up the generated aluminum chips. Step S332: Repeat step S331, remove the CCS or the bar, and clean the aluminum chips to expose the specific location to be repaired.

5. The power battery repair method according to claim 1, characterized in that: Step S340 includes the following steps: Step S341: Remove the FPC or other components with poor welding; Step S342: repairing the pole hole; Step S343: using a grinding gun to grind the pole; Step S344: Clean the box and the poles.

6. A power battery repair method according to claim 5, characterized in that: During the pole grinding process, the grinding effect and pole height need to be checked in real time; the surface flatness of the pole after grinding is 0-0.5mm; the pole height is greater than the pole insulation sleeve height.

7. The power battery repair method according to claim 1, characterized in that: Step S420 includes the following steps: Step S421: removing the binding belt, using an angle grinder to cut off the binding belt of the fixed module; Step S422: Remove the module end plate, insert a wedge plate into the gap between the battery cell and the end plate, and then use a hammer to gently tap the wedge plate, gradually applying force to separate the end plate from the battery cell; Step S423: Remove the module cells by inserting a wedge plate into the gap between adjacent cells and then gently tapping the wedge plate with a hammer until the cells are separated; Step S424: removing the heating film; Step S425: cleaning foreign matter.

8. The power battery repair method according to claim 1, characterized in that: Step S440 further includes the following steps: Step S441: Pack the package for glue removal protection, and wrap and cover the area where glue removal is required with insulating tape; Step S442: Remove glue from the bottom surface of the box body. First, perform low-speed milling on the bottom surface of the box body with a feed depth of 0.2mm-0.5mm. After the milling is completed, switch to a grinding gun to grind and clean the residual glue and remove glue chips. Step S443: Remove the glue on the bottom side of the box body. First, perform low-speed milling on the glue on the bottom side of the box body until the remaining thickness of the glue surface is 1.0mm-1.2mm. Then, switch to the grinding gun to grind and clean the residual glue until the remaining thickness of the glue surface is 0.8mm-1.0mm. Then stop grinding and clean the glue scraps. Step S444: Remove the insulating tape.

9. The power battery repair method according to claim 1, characterized in that: Step S400 further includes the following steps: Step S450: Gluing the bottom of the box; Step S460: The module is put into the box.

10. The power battery repair method according to claim 1, characterized in that: Also includes: Step S500: After the accessory removal path is completed, CCS / bar welding is performed; Step S600: Assembling, which includes online material inspection, replacement of new FPC or other components, copper busbar installation, completion of battery pack assembly and assembly torque recording; Step S700: Perform testing and verification, including OQC full inspection, insulation withstand voltage test, EOL test and charge and discharge test.

Images