Application Of Ultrasonic Atomization Spraying Equipment in Battery Film Electrode Spraying
Apr 22, 2026
120kHz high-frequency ultrasound is the preferred process for ultra-thin, ultra-low platinum catalyst layers in PEM hydrogen fuel cells. The droplets are 15–25μm, without coffee rings, and the platinum utilization rate is ≥95%, which can precisely create membrane electrodes with high ECSA, long life and low loading.
I. Membrane Electrode Structure & Spraying Method
MEA Three-Layer Core
Proton Exchange Membrane (Nafion 211/212) → Cathode Pt/C Catalyst Layer CL → Anode IrO₂/RuO₂ Catalyst Layer → GDL Gas Diffusion Layer
Two Mainstream Spraying Routes
1. CCM Direct Spraying (Mainstream): Catalyst slurry is directly sprayed onto the proton exchange membrane, then hot-pressed onto the GDL layer.
Advantages: Extremely low interfacial resistance, optimal three-phase interface, suitable for ultra-low platinum mass production.
2. GDE Spraying Diffusion Layer: Spraying carbon paper/carbon cloth, then bonding the proton exchange membrane.
Advantages: Membrane is less prone to damage, suitable for large-area mass production.
II. Pt/C Cathode Paste Formulation (120kHz Dedicated)
* Ratio: Pt/C : Nafion binder = 2 : 1
* Solid content: 8–12 wt% (golden range)
* Viscosity: 15–30 cP, strictly prohibited >35 cP to prevent nozzle clogging
* Solvent: Ethanol + deionized water mixture, ultrasonically dispersed for 30 min + multi-stage filtration
* Contraindications: Solid content <5% easily leads to agglomeration and sagging; Solid content >15% extremely easily causes nozzle clogging and porosity deterioration
III. 120kHz MEA Standard Process Parameters
* Ultrasonic Frequency: 120 kHz
* Ultrasonic Power: 40–60 W (>60W strictly prohibited as it will damage the proton exchange membrane)
* Slurry Flow Rate: 0.05–0.3 mL/min (for ultra-low platinum ultrathin layers)
* Nozzle Distance: 50–80 mm
* Scanning Speed: 8–20 mm/s, serpentine reciprocating cross path
* Carrier Gas (N₂): 0.02–0.04 MPa, low-pressure shaping to prevent membrane damage
* Substrate Heating: 50–70℃, rapid drying, inhibiting platinum migration and agglomeration
* Target Platinum Loading: 0.05–0.2 mg/cm², CV Uniformity <3%