Electrode sheet cutting (especially for lithium-ion battery positive/negative electrodes) is a critical step in new energy battery production. However, dust (such as active material powder and metal debris) and burrs (tiny protrusions on the cutting edge) generated during cutting directly affect battery performance: dust may cause short circuits between positive and negative electrodes, while burrs can pierce separators, leading to safety hazards. Additionally, they increase equipment wear and workshop environmental pressure. Eliminating these issues cannot rely on a single measure; a comprehensive solution must be built around four dimensions: optimized cemented carbide tools, precise cutting parameter control, equipment accuracy assurance, and coordinated dust removal and deburring auxiliary systems. Among these, the selection and maintenance of cemented carbide tools are core (directly determining the initial generation of dust and burrs). This article details specific operational methods for each link, providing actionable solutions to help reduce dust during electrode sheet cutting by over 80% and control burrs within 0.1mm.
1. First, Identify the Root Causes: Main Sources of Dust and Burrs in Electrode Sheet Cutting
Before developing solutions, it is essential to clarify the root causes to avoid "blind measures." Dust and burrs in electrode sheet cutting (taking lithium-ion battery electrodes as an example, with substrates mostly aluminum foil/copper foil and coated active materials) mainly stem from the following four factors:
- Inappropriate Tool Selection and Condition: Using ordinary cemented carbide tools (e.g., YG6) to cut positive electrode sheets with hard-coated active materials leads to rapid tool wear and metal debris (dust). Alternatively, unpassivated cutting edges cause stress concentration during cutting, resulting in active material detachment (dust) and burrs on the substrate edge.
- Unreasonable Cutting Parameter Settings: Excessively high cutting speed (e.g., over 30m/min) causes friction-induced heat between the tool and electrode sheet, leading to active material detachment. Excessively large feed rate (e.g., over 0.2mm/r) over-squeezes the electrode substrate, creating burrs on the edge.
- Insufficient Equipment Accuracy: Excessive spindle runout (e.g., over 0.01mm) causes uneven force on the tool during cutting, leading to local overload and burrs. Poor workbench positioning accuracy (e.g., over 0.02mm) shifts the cutting path, resulting in irregular dust and burrs on the edge.
- Lack of Effective Auxiliary Systems: No targeted dust removal device is configured to expel generated dust in a timely manner. There is no in-line deburring process after cutting, leaving tiny initial burrs unremoved.
2. Core Solutions: A Systematic Approach Across Four Dimensions
1. Optimization of Cemented Carbide Tools: Minimize Dust and Burrs at the Source
Electrode sheet cutting has high requirements for tool "wear resistance, edge smoothness, and toughness." Priority must be given to selecting suitable cemented carbide tools and maintaining them properly—this is the foundation for reducing dust and burrs.
(1) Tool Material Selection: Prioritize "Wear Resistance + Chipping Resistance" to Match Electrode Sheet Characteristics
Different electrode substrates (aluminum foil/copper foil) and coating hardness require precise tool material matching:
- Lithium-Ion Battery Positive Electrodes (aluminum foil substrate + hard active materials, e.g., ternary materials): Recommend a cemented carbide formula of fine-grain WC (1-2μm) + 6%-8% Co + 5% TiC. Fine-grain WC enhances wear resistance, reducing metal dust from tool wear. TiC improves high-temperature stability, preventing active material detachment due to frictional heat during cutting. 6%-8% Co balances toughness, avoiding edge chipping and burrs.
- Lithium-Ion Battery Negative Electrodes (copper foil substrate + soft active materials, e.g., graphite): Recommend a cemented carbide formula of medium-grain WC (2-3μm) + 8%-10% Co. Copper foil is soft and prone to sticking to tools; medium-grain WC reduces dust caused by tool sticking. High Co content enhances toughness, preventing wrinkling and burrs on the copper foil edge during cutting.
(2) Tool Edge Treatment: Reject "Sharper = Better" and Focus on "Smoothness + Passivation"
Many assume "the sharper the tool edge, the better," but in electrode sheet cutting, overly sharp edges are prone to chipping (especially when cutting hard coatings), which actually generates more burrs and dust. The correct edge treatment methods are:
- Edge Polishing: Use a diamond grinding wheel for precision grinding to achieve an edge surface roughness of Ra ≤ 0.2μm. This reduces friction between the edge and electrode sheet, lowering active material detachment (dust reduction by over 40%).
- Edge Passivation: Control edge sharpness to 0.01-0.02mm (not absolutely sharp). Use a dedicated passivation machine to slightly round the edge, avoiding chipping and burrs (burr rate reduced from 5% to below 0.5%).
(3) Tool Maintenance: Regular Wear Checks to Avoid "Cutting with Defects"
When tool flank wear exceeds 0.1mm, the tool must be re-sharpened or replaced promptly (electrode sheet cutting is more sensitive to tool wear—while the wear threshold for general metal cutting is 0.3mm, this must be strictly controlled here):
- Use a diamond grinding wheel (grain size 200-400 mesh) for re-sharpening to ensure edge accuracy meets initial standards.
- Clean the spindle and tool positioning surface before installing the tool each time to avoid tool tilting caused by iron chips (tilting exacerbates local wear and generates irregular burrs).
2. Precise Cutting Parameter Control: Avoid "Overload Cutting" to Reduce Dust and Burrs
Parameters must be adjusted based on electrode sheet thickness (typically 0.1-0.3mm) and substrate material to avoid "excessive friction" or "over-squeezing" caused by improper settings. The following are parameter references for common electrode sheets (using cemented carbide circular knives for cutting):
| Electrode Sheet Type | Cutting Speed (m/min) | Feed Rate (mm/r) | Cutting Depth (mm) | Common Incorrect Parameters & Consequences |
|---|---|---|---|---|
| Lithium-ion positive electrode (0.2mm) | 15-25 | 0.08-0.12 | 0.25-0.3 | Speed = 30m/min: Frictional heat increases active material detachment by 50% |
| Lithium-ion negative electrode (0.15mm) | 20-30 | 0.1-0.15 | 0.2-0.25 | Feed rate = 0.2mm/r: Copper foil deformation causes burr rate to exceed 3% |
| Sodium-ion battery positive electrode (0.25mm) | 12-20 | 0.07-0.1 | 0.3-0.35 | Depth = 0.4mm: Over-cutting causes dust on the substrate edge |
Parameter Setting Principles:
- Hard Materials (positive electrodes): Low speed + small feed rate to avoid tool overload and wear.
- Soft Materials (negative electrodes): Medium-high speed + moderate feed rate to reduce dust from tool sticking.
- Cutting Depth: Only 0.05-0.1mm greater than the electrode sheet thickness—no over-cutting (over-cutting increases substrate fragmentation risk and generates more dust).
3. Equipment Accuracy Assurance: Reduce "Mechanical Errors" to Avoid Additional Issues
Even with proper tools and parameters, insufficient equipment accuracy can still cause dust and burrs. Two key accuracy indicators must be prioritized:
(1) Coaxiality of Spindle and Tool
Spindle runout must be ≤ 0.005mm (measured with a micrometer at the spindle end). Excessive runout (e.g., over 0.01mm) causes the tool to rotate "eccentrically" during cutting, leading to over-cutting (dust) or under-cutting (residual burrs) on local areas of the electrode sheet.
- Solution: Regularly clean spindle bearings and replace worn bearings. Use locating pins to position the tool during installation, ensuring coaxiality between the tool and spindle.
(2) Workbench Positioning Accuracy
The X/Y-axis positioning accuracy of the workbench must be ≤ 0.01mm, and repeatability accuracy ≤ 0.005mm. This prevents cutting path deviation and irregular dust/burrs on the electrode edge.
- Solution: Calibrate workbench accuracy with a laser interferometer monthly. Conduct test cuts with standard templates before mass production to confirm positioning accuracy.
4. Dust Removal and Deburring Auxiliary Systems:彻底清除残留问题
Even if dust and burrs are minimized at the source, auxiliary systems are still needed for "secondary treatment" to ensure final product quality.
(1) Dust Removal Systems: Combine "Dry + Wet" Methods Based on Scenarios
- Dry Dust Removal (for dry electrode sheets, e.g., uncoated substrates): Adopt a "local sealing + negative pressure suction" design. Install a sealed cover around the cutting area, with 3-4 directional air ducts (positioned 5-10mm above the cutting point). Control suction air speed at 8-12m/s to collect over 90% of dry dust.
- Wet Dust Removal (for coated electrode sheets sensitive to static electricity): Install a spray device (using deionized water to avoid electrode contamination) below the cutting point. Combine with negative pressure suction to collect the water mist-dust mixture, which is filtered for recycling. This effectively prevents dust dispersion (especially suitable for lithium-ion battery positive electrodes, where active material dust is flammable—wet methods are safer).
(2) Deburring Systems: "In-Line + Off-Line" Dual Protection
- In-Line Deburring (process immediately after cutting to avoid burr deformation): Install an "elastic brush + hot air drying" module after the cutting station. Use nylon brushes (hardness 50-60 Shore A) rotating at 300-500r/min, with light contact pressure (0.1-0.2MPa) on the electrode edge. This removes over 80% of tiny burrs. Follow with hot air drying (40-60℃) to remove residual moisture.
- Off-Line Deburring (for high-precision requirements, e.g., power battery electrodes): Use laser deburring technology. Focus a 1064nm fiber laser on burrs at the electrode edge (spot diameter 0.05mm), melting burrs with high temperature. This achieves accuracy up to 0.001mm without damaging the electrode substrate (suitable for scenarios requiring burr rates ≤ 0.05mm).
3. Clarifying Common Misconceptions: Avoid the Trap of "Single Measures"
Many enterprises struggle to solve these issues because they fall into the trap of "prioritizing single measures," leading to poor results. The following three common mistakes require attention:
Misconception 1: "As long as the tool is sharp enough, burrs can be avoided."
Fact: Tool edges for electrode sheet cutting need "moderate sharpness." Overly sharp edges are prone to chipping (especially when cutting hard coatings), generating more burrs. A battery manufacturer used unpassivated cemented carbide tools to cut positive electrodes—edges chipped within 2 hours, with a burr rate of 5%. After switching to passivated tools (edge 0.015mm), edges lasted 8 hours without chipping, and the burr rate dropped to 0.08mm.
Misconception 2: "Dust removal only requires high-suction suction—sealing is unnecessary."
Fact: Suction without sealing causes dust dispersion (only ~60% collected). A factory without a sealed cover still had large amounts of dust floating in the workshop despite a suction speed of 15m/s. After adding a sealed cover, dust collection rate increased to 95% even with the suction speed reduced to 10m/s, while reducing contamination of other equipment.
Misconception 3: "Manual grinding is more accurate for deburring."
Fact: Manual grinding is inefficient (50-100 sheets processed per person per hour) and easily damages electrodes (uneven pressure causes substrate deformation). A factory using manual grinding had an electrode scrap rate of 3%. After switching to in-line brush deburring, efficiency increased to 5,000 sheets per hour, scrap rate dropped to 0.1%, and overall costs decreased by 60%.
4. Implementation Results: Key Indicator References
After implementing the above comprehensive solution, core indicators for electrode sheet cutting (taking lithium-ion battery electrodes as an example) can reach the following levels:
- Dust Level: Dust residue ≤ 5mg per square meter of electrode sheet (85% reduction compared to pre-optimization).
- Burr Rate: Edge burr length ≤ 0.1mm, with a pass rate of over 99.5%.
- Tool Life: Continuous cutting life of cemented carbide tools increased from 500,000 sheets to 1,200,000 sheets (reducing tool changes and gap pollution from dust).
- Workshop Dust Concentration: Complies with the Battery Industry Pollutant Emission Standard (GB 30484-2013), with workshop air dust concentration ≤ 3mg/m³.
5. Conclusion: Comprehensive Solutions Are Key, Source Control Is Core
Eliminating dust and burrs in electrode sheet cutting cannot rely on "symptom-based" single measures—optimization of cemented carbide tools is the source (reducing initial generation), parameters and equipment accuracy are guarantees (avoiding additional issues), and dust removal/deburring systems are supplements . For professionals in the tungsten carbide industry, tool recommendations should include "material formula + edge treatment + maintenance advice" tailored to specific electrode characteristics (e.g., substrate, coating hardness), rather than just general models.
If your enterprise still struggles with dust and burrs in electrode sheet cutting, or needs customized tool and parameter solutions for specific electrodes (e.g., sodium-ion battery, solid-state battery electrodes), feel free to communicate. We can provide cemented carbide tool sample testing and cutting parameter adjustment guidance to help you implement the solution quickly.