Why Pulsed Laser Cleaning Becomes the Preferred Process for Power Battery Production Lines

Introduction: With the rapid expansion of the new energy vehicle industry, power batteries serve as the core component of vehicles. Every pre-treatment and welding auxiliary process directly determines battery safety, cruising range and mass production cost. Traditional processes including pickling, sandblasting, manual polishing and ultrasonic cleaning expose obvious defects on thin-walled aluminum parts, precision poles and sealed water-cooled plates. Featuring low heat input, dry operation without consumables and selective substrate peeling, pulsed laser cleaning has formed stable application solutions in key lithium battery processes, and has been widely adopted by leading battery manufacturers and PACK factories.

I. Common Cleaning Pain Points of Lithium Battery Factories (Traditional Processes Fail to Solve)

After field research on dozens of power battery and energy storage PACK manufacturers, front-line process engineers are troubled by four major pain points:

1. Aluminum Battery Tray & Water-cooled Plate: Thin Plate Deformation & Anti-corrosion Coating Damage

Battery trays and water-cooled plates are mostly thin-walled aluminum alloy structures with dense internal flow channels, sealing planes and threaded holes.
  • Chemical Pickling: Corrodes aluminum substrates, residual ions cause later sealing failure, generates massive hazardous waste, and increases annual environmental disposal costs;
  • Sandblasting: Particle impact deforms thin plates, blocks tiny water-cooled flow channels, and wears off electrophoretic anti-corrosion coatings, shortening the service life of battery packs;
  • Manual Polishing: Dead corners such as rib grooves and threaded holes cannot be cleaned thoroughly, damaging the flatness of sealing planes and causing leakage risks after assembly.

2. Cell Poles & Copper-aluminum Busbars: Oxide Layer Causes Cold Welding & Heat Accumulation Risks

Micron-scale alumina film and tiny electrolyte residue on pole surfaces will increase contact resistance. Long-term charge and discharge of modules will lead to local overheating, bringing hidden safety hazards.
  • Solvent Soaking Cleaning: Electrolyte ions cannot be completely removed, causing potential short-circuit risks in long-term operation;
  • Manual Sanding: Uneven force scratches pole coatings, poor batch consistency and high welding defect rate;
  • Dry Ice Cleaning: Fails to clean tiny gaps thoroughly, residual dust adheres to conductive parts and increases inspection rework volume.

3. Battery Shells, Sealing Nails & Module Connectors: High Dimensional Tolerance Requirements, No Substrate Loss Allowed

Stamping oil stains on battery shells, electrolyte residue on liquid injection holes, and oxidized black spots on busbars require fixed-point partial cleaning. Traditional contact cleaning changes workpiece dimensions, leaves scratches and deformation on thin-walled parts, failing to meet the strict dimensional tolerance standards of power batteries.

4. Dual Pressure from Environmental Compliance & Mass Production Cost

Pickling produces waste water and hazardous waste; sandblasting leads to excessive workshop dust and frequent environmental inspection restrictions. Multiple manual cleaning procedures consume massive labor resources, and rework & scrappage bring rising hidden production costs.

II. Core Application Scenarios of Pulsed Laser Cleaning in Full Lithium Battery Production Process

Based on nanosecond pulsed instantaneous vaporization principle, this process brings ultra-small heat-affected zone, only peels off surface contaminants, and retains original substrate materials and protective coatings, covering front, middle and back-end lithium battery production procedures:

Scenario 1: Pre-welding & Post-welding Cleaning for Battery Trays and Water-cooled Plates

Accurately removes CMT welding oxide scale, rolling oil stains and stamping oxide layers, covering dead corners including deep rib grooves, micro holes and threaded holes.
Mass Production Test Data: Stable cleaning cleanliness, no scratches or deformation on substrates, complete retention of original electrophoretic anti-corrosion coatings; reduced welding contact resistance and improved heat dissipation uniformity of battery packs; lower welding rework rate, several times higher cleaning efficiency than traditional processes, compatible with 6-axis robot integration for 24-hour automatic production.

Scenario 2: Pre-welding Treatment for Cell Poles and Copper-aluminum Busbars

Cooperated with CCD visual positioning and laser galvanometer, it removes surface alumina film and tiny electrolyte residue on poles in fixed points. The cleaning area is controlled within micron scale without damaging peripheral insulating coatings.
Core Advantages: Uniform surface cleanliness after cleaning, stable welding bonding strength and reduced production defect rate. Full dry operation without liquid residue eliminates battery short-circuit risks, compatible with prismatic, cylindrical and pouch cell mass production lines.

Scenario 3: Cleaning for Battery Shells, Sealing Nails and Liquid Injection Holes

Removes stamping lubricant on shells and electrolyte residue on sealing nails to avoid welding spatter and black spots. Slightly roughens shell surfaces to enhance adhesion of insulating film and sealant, reducing bubble and wrinkling defects. No soaking or medium residue, meeting cleanliness standards of power battery dust-free workshops.

Scenario 4: Maintenance & Rework Cleaning for Energy Storage Modules and Battery Packs

Performs localized rust and oxide removal for disassembled module connectors and rusted busbars. Equipped with lightweight handheld cleaning heads, it operates flexibly in narrow assembly spaces without integral module disassembly, greatly shortening reworking time.

III. Five Core Advantages of Pulsed Laser Cleaning vs. Traditional Processes (Compliant Expression)

1. Substrate-friendly, High Adaptability for Thin-walled Precision Parts

Pulsed laser releases energy instantly with low overall workpiece temperature rise. No mechanical impact or chemical corrosion occurs. The dimension, coating and metallographic structure of aluminum alloy, copper, thin shell and precision conductive parts remain unchanged, fitting all thin-walled precision components of power batteries.

2. Selective Layered Peeling, Retain Original Anti-corrosion Coatings

Laser energy can be precisely adjusted to remove oxide, oil stains and welding spatter only, while keeping tray electrophoretic coatings and pole protective coatings intact. No secondary anti-corrosion treatment is required, simplifying production procedures.

3. Eco-friendly Dry Process, Lower Environmental Compliance Pressure

No chemical agents, waste water or waste residue generated in the whole process. Only simple dust collection system is equipped to collect tiny dust. It cuts expenditure on hazardous waste and sewage treatment, improves workshop dust and liquid pollution, and meets strict environmental regulations worldwide.

4. Controllable Long-term Operation Cost, Suitable for Large-scale Mass Production

No consumables such as sand materials, cleaning agents and sandpaper are required, only regular optical component maintenance. The equipment can connect with workshop MES system to call cleaning parameters for different workpieces with one click. Automated operation replaces manual work, cutting labor cost and bringing comprehensive cost advantages in long-term mass production.

5. Flexible Compatibility for Multi-spec Production, Support Old Production Line Renovation

One device supports process switching for trays, poles and shells, with dual modes of handheld operation and robot automatic operation. Old production lines can be renovated without large layout adjustment, integrating into existing welding and assembly procedures quickly, applicable for power battery, energy storage and battery swap production lines.

IV. Verified Mass Production Cases & Practical Improvement Effects

A leading PACK manufacturer in East China originally adopted pickling + polishing for battery tray welding treatment, facing problems including thin plate deformation, high hazardous waste cost and high welding defect rate.
After introducing automatic 300W pulsed laser cleaning production line, the practical improvements are as follows:
  1. Complete removal of welding oxide layer, no substrate damage and complete retention of electrophoretic coatings;
  2. Decreased welding defect rate, rework proportion and workpiece scrappage;
  3. Pickling procedure cancelled, annual hazardous waste disposal cost reduced, all environmental inspections passed;
  4. Shorter single tray cleaning time, optimized production line rhythm and stable 24-hour continuous production.
After adopting pole laser cleaning procedures, multiple energy storage cell manufacturers report fewer local overheating feedbacks during module charge-discharge cycles, higher factory inspection pass rate and fewer after-sales safety complaints.

V. Recommended Application Conditions for Pulsed Laser Cleaning in Power Battery Industry

Pulsed laser cleaning delivers stable production performance if meeting any of the following conditions:
  1. Thin-walled aluminum/copper precision parts that forbid deformation, scratch and substrate corrosion;
  2. Layered cleaning required: only remove surface contaminants while retaining anti-corrosion/insulating coatings;
  3. Dust-free workshop management, no liquid or chemical medium residue allowed (cell & pole procedures);
  4. Strict environmental supervision, need to reduce waste water and hazardous waste output;
  5. Multi-spec workpieces co-produced on one line, requiring fast flexible process switching;
  6. Automatic production line upgrading, needing integrated cleaning process with minimal manual intervention.

VI. Conclusion: Cleaning Process Upgrade Trend of Lithium Battery Manufacturing

With tightening power battery safety standards and environmental policies, the defects of pickling, sandblasting and other traditional processes are increasingly prominent. Featuring non-damage, dry operation, automation and low operation cost, pulsed laser cleaning is popularized among leading lithium battery factories, becoming the mainstream cleaning process for battery trays, poles and water-cooled plates.
Essentially, manufacturing process upgrading balances production yield, operational safety, environmental compliance and production cost. If you are troubled by welding defects, workpiece loss, environmental rectification and high manual cleaning cost, pulsed laser cleaning is worthy of sample testing to verify application effects matching your production line conditions.
What cleaning process does your production line adopt currently? What unsolvable pain points do you meet? Leave a comment for communication.

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