Application Principles and Mechanisms of Laser Cleaning in Battery Production

Laser cleaning technology plays a crucial role in battery manufacturing. With its high efficiency, environmental friendliness, and non-contact nature, it has become a key process in modern battery production. This article analyzes the application of laser cleaning in battery manufacturing from multiple perspectives: core working principles, technical features and advantages, typical application scenarios, comparisons with traditional cleaning methods, key parameter control, and future development trends.

I. Core Working Principles of Laser Cleaning

Laser cleaning is a non-contact process that uses a high-energy-density laser beam to irradiate material surfaces. Through the interaction between light and matter, surface contaminants are removed. In battery production, its mechanisms can be summarized as follows:

1. Photothermal Decomposition and Vaporization Effect

• Principle: The contaminant (e.g., organics, oxides) absorbs laser energy, which is rapidly converted into heat. The contaminant temperature rises sharply to its decomposition or vaporization point, causing it to detach from the substrate.
• Application: Removal of electrolyte residues, binder overflow, or carbon particles from electrode surfaces.
• Example: After electrode cutting, residual binder or burrs can be decomposed or evaporated by laser irradiation.

2. Photoablation and Shock Wave Effect

• Principle: Short-pulse lasers (e.g., nanosecond or picosecond) rapidly deposit energy, causing contaminants to expand and produce shock waves that strip them from the substrate. Plasma-induced explosions can also provide mechanical force to remove pollutants.
• Application: Removing oxide layers from copper/aluminum foils or surface pretreatment before welding.
• Example: Before tab welding, laser cleaning removes Al₂O₃ from aluminum foil to improve bonding strength.

3. Photochemical Decomposition Effect

• Principle: Specific laser wavelengths (e.g., UV) trigger photochemical reactions with contaminants, breaking molecular bonds and decomposing them into volatile molecules (e.g., CO₂, H₂O).
• Application: Removing organic contaminants such as oil or photoresist residues from cathode materials.
• Feature: Mild process that avoids thermal damage, suitable for high-precision cleaning.

4. Ablation and Melting Removal

• Principle: High-power lasers directly melt or vaporize contaminants (e.g., metal particles, welding spatter), which are then blown away by an assist gas.
• Application: Removing welding spatter or impurities from battery cases to ensure sealing integrity.

II. Why Is Laser Cleaning Suitable for Battery Manufacturing? — Technical Features and Advantages

III. Typical Application Scenarios in Battery Manufacturing

1. Electrode Surface Pretreatment
   Removes burrs, binder splashes, or oxides after cutting to ensure uniform density.
2. Pre-welding Surface Cleaning
   Eliminates oxide layers or contaminants to improve welding strength and conductivity.
3. Battery Case and Cap Cleaning
   Removes oil, spatter, or debris from stamping and welding to ensure sealing and insulation.
4. Separator and Coating Cleaning
   UV lasers gently remove dust or coating defects without damaging microporous structures.

IV. Comparison with Traditional Cleaning Methods

V. Key Parameter Control in Laser Cleaning

• Power density: Typically 10–100 W/mm². Excessive levels may damage substrates.
• Pulse frequency & width: Nanosecond pulses minimize heat effects; longer pulses for thicker layers.
• Scanning speed & overlap: 100–1000 mm/s with 50–70% overlap ensures uniformity.

VI. Case Studies

1. Integrated Cleaning and Welding Equipment
   A dedicated system combines pre-welding laser cleaning and laser welding for battery lids, achieving high efficiency and weld quality.
2. Anode Laser Cleaning
   Optimized parameters enable precise cleaning of anode surfaces, significantly improving weld reliability and overall battery quality.

VII. Summary

Laser cleaning offers high precision, non-contact operation, and customizable solutions, making it indispensable in battery production. By leveraging photothermal, photochemical, or mechanical effects, it ensures contaminant removal without damaging substrates. With growing demands for higher energy density and automation, laser cleaning is set to play an even greater role in electrode processing and sealing.

VIII. Laser Cleaning Equipment and Process Optimization

1. Laser Cleaning Equipment
   Standard systems include pulsed fiber lasers, control units, and cleaning heads. Configurations are customized for different contaminants and production requirements.
2. Process Optimization

• Low power and short pulses for light contaminants like oil.
• Higher power and longer pulses for thick oxide layers.
• Adjustments ensure precise and efficient removal without substrate damage.

IX. Industry Value and Advantages

1. Environmental Friendliness
   No chemicals, solvents, or wastewater. Prevents defects such as hydrogen embrittlement common in wet cleaning.
2. Economic Benefits
   Although initial investment is higher, long-term savings in consumables and labor reduce overall costs.
3. Process Compatibility
   Seamlessly integrates with automated production lines and roll-to-roll processes for continuous cleaning and monitoring.
4. Quality Improvement
   Improves electrode uniformity and welding yields, reducing defects and enhancing consistency and lifespan.

X. Challenges and Future Trends

1. Current Challenges

• Deep cleaning of thick contaminants (>100 μm) requires costly high-power lasers.
• Precision decreases on complex surfaces like battery housings.

2. Future Directions

• Multi-wavelength cleaning for different contaminants.
• AI-based parameter optimization to reduce trial-and-error.
• Flexible cleaning heads for complex geometries with micron-level accuracy.

XI. Conclusion

Laser cleaning, with its precision, non-contact nature, and adaptability, has become a core technology in battery manufacturing. It ensures contaminant removal without substrate damage, meeting stringent cleanliness and safety standards in lithium battery production. As automation and performance requirements increase, laser cleaning will continue to grow in importance, supporting efficient, sustainable, and high-quality battery manufacturing.