EUV 172nm Lamp for Surface Cleaning of Solid-State & Flexible Batteries
Core Role: 10–20μm Material Surface Modification for Enhanced Product Coupling
EUV 172nm excimer lamps (vacuum ultraviolet VUV light sources) are key technologies in the manufacturing of solid-state and flexible batteries, enabling deep cleaning and precise modification of the 10–20μm surface layer. Through high-energy photon photochemical reactions, they thoroughly remove organic contaminants and precisely activate surface structures, significantly improving interfacial bonding strength between electrodes, electrolytes, and encapsulation layers, as well as overall battery stability.
1. Core Technical Characteristics of 172nm Light Sources
The 172nm excimer lamp emits high-energy monochromatic vacuum ultraviolet light at 7.2eV. Different from conventional UV and extreme ultraviolet EUV (13.5nm), it combines high energy with moderate penetration, ideally matching surface modification requirements for battery materials:
High-energy bond breaking: Photon energy far exceeds the bond energy of organic bonds such as C–C, C–H, and C–O (2.5–4.5eV), enabling direct breakdown of contaminant molecular chains.
Precise penetration depth: In solid-state/flexible battery materials (sulfides, oxides, polymers, metal foils, flexible thin films), the effective treatment depth is accurately controlled at 10–20μm without damaging the internal bulk structure.
Strong reactive oxygen generation: Its absorption coefficient for O₂ is 20 times that of 185nm UV, efficiently producing ozone (O₃), highly reactive atomic oxygen (O*), and hydroxyl radicals (•OH), forming a dual "photolysis + oxidation" cleaning mechanism.
Low-temperature, damage-free processing: As a cold light source, it operates at room temperature with no thermal stress or mechanical damage, making it suitable for heat-sensitive and fragile materials such as solid electrolytes and flexible substrates.
2. Dual Core Functions for Solid-State & Flexible Batteries: Cleaning + Modification
2.1 Ultra-Clean Surface Cleaning (10–20μm): Complete Removal of Interfacial Contaminants
Interfacial contamination (release agents, oil, fingerprints, organic residues, micro-dust) is a major cause of high interfacial resistance, poor ion transport, and short cycle life in solid-state and flexible batteries. 172nm phot cleaning achieves molecular-level cleanliness:
Direct photolysis: 172nm photons directly break down large organic contaminant molecules within the 10–20μm surface layer into small fragments.
Oxidative volatilization: Reactive oxygen reacts with organic fragments to form volatile gases such as CO₂ and H₂O, which are completely removed from the surface.
Dry, residue-free process: No chemical reagents, no waste liquid, no secondary pollution, resulting in molecular-level surface cleanliness.
2.2 Deep Material Modification (10–20μm): Strengthening Interfacial Coupling and Performance
Cleaning is synchronized with precise modification of the 10–20μm surface layer, optimizing interfacial properties at the molecular level to solve the industry pain point of "weak interlayer coupling":
Surface hydrophilization and activation: Introduction of polar groups such as –OH (hydroxyl) and –COOH (carboxyl) increases surface energy from <30 dynes/cm to >70 dynes/cm and reduces contact angle from 75° to <15°, greatly improving wettability and adhesion between electrodes and electrolytes.
Microstructure optimization: Formation of a nano-scale rough activated surface within the 10–20μm layer increases interfacial contact area by 30–50%, enhancing physical interlocking and ion transport channel density.
Enhanced interfacial chemical bonding: Active sites formed on the activated surface promote stable covalent/ionic bonding between electrodes and electrolytes and between multilayer films. Interfacial bonding strength is improved by 2–5 times, suppressing the increase of interfacial resistance in solid-state batteries and interlayer delamination in flexible batteries.
Thin-film stress relief: Mild modification eliminates internal stress in battery films (current collectors, solid electrolytes, encapsulation films), improving bending and tensile stability of flexible batteries and reducing crack formation during cycling.
3. Key Process Application Scenarios (Solid-State & Flexible Batteries)
3.1 Core Interface Treatment for Solid-State Batteries
Cathode / Anode thin electrodes: Clean residual binders and agglomerated carbon powder, activate the 10–20μm surface layer, and improve wettability and bonding with sulfide/oxide solid electrolytes.
Solid electrolyte sheets: Remove processing oil and dust, modify the surface layer to reduce interfacial resistance, and improve dense contact with electrodes to minimize the space charge layer effect.
Composite cathodes (cathode + electrolyte): Activate particle surfaces, strengthen solid–solid interfacial contact, and improve ion transport efficiency and cycle stability.
3.2 Full-Process Adaptation for Flexible Batteries
Flexible current collectors (Cu foil / Al foil / flexible films): Clean surface passivation layers and organic residues, perform 10–20μm modification to improve adhesion of active materials and prevent peeling during bending.
Multilayer flexible film encapsulation: Activate PET/PI/Al composite film surfaces to improve interlayer lamination/adhesion strength and prevent leakage and gas permeability.
Ultra-thin electrodes / electrolytes (<50μm): Damage-free cleaning and modification maintain film integrity, supporting rolling and folding processes.
4. Technical Advantages vs. Conventional Processes
| Process | Cleaning Depth | Modification Effect | Material Damage | Environmental Performance | Interfacial Coupling Improvement |
|---|---|---|---|---|---|
| 172nm Excimer Cleaning | 10–20μm, precisely controllable | Hydrophilization + polar groups + micro-roughening | No thermal/mechanical damage, low-temperature dry process | No chemicals, zero pollution | Significant (2–5×) |
| Conventional wet chemical cleaning | Uncontrollable, easy over-etching | Weak, easy residue formation | Corrosion/swelling, surface damage | High waste liquid, environmental burden | Moderate |
| Plasma cleaning | <5nm, too shallow | Surface activation, insufficient depth | Easy bombardment damage, defects | Requires vacuum, high cost | Limited |
| Mechanical polishing | Uneven, easy structural damage | Physical roughening, no chemical activation | Severe, micro-cracks generated | High dust, pollution | Low, easy peeling |
5. Conclusion
The EUV 172nm excimer lamp is a critical surface treatment technology for solid-state and flexible battery manufacturing. With its dual functions of 10–20μm deep ultra-cleaning and precise surface modification, it fundamentally solves core problems including interfacial contamination, weak coupling, high resistance, and poor stability. By improving interfacial bonding, ion transport efficiency, and structural reliability, it directly enhances battery energy density, cycle life, and safety performance, making it an essential enabling technology for the industrialization of next-generation advanced batteries.
