Tsingyan Powder-into-Film (PIF) Technology - Dry Electrode Coating Technology

• Incubated by Research Institute of Tsinghua University in Shenzhen, boasting advanced technology.

• Professional team with substantial strength.

• Patented technology for outstanding performance for energy storage in China.

• Diverse products are available to provide one-stop solutions.

1. Raw Material Preparation

The dry electrode processing begins with the dry blending of three core components:

Active material (e.g., NCM for cathodes, graphite for anodes) determines energy density.

Conductive additives (carbon black, CNTs) compensate for PTFE’s insulation.

PTFE binder (3–5% by weight) replaces solvents, forming a fibrillated network.

Critical requirement: Homogeneous mixing to prevent agglomeration, typically using high-shear planetary mixers.

2. PTFE Fibrillation

During blending or subsequent roller shearing, mechanical force induces PTFE fibrillation—where the binder forms a 3D fibrous mesh. This:

Enhances electrode mechanical strength.

Eliminates the need for solvents (unlike wet slurry processes).

Maintains thermal stability (−200°C to +260°C).

3. Calendering: Dry Powder Compression

The dry mixture is fed into a calender (heated rollers at 80–120°C) under high pressure (10–50 tons) to:

Compress the powder into a freestanding electrode film.

Optimize density (e.g., ~3.4 g/cm³ for anodes).

Challenge: Balancing pressure to avoid cracking the Al/Cu current collectors.

4. Lamination to Current Collectors

The calendered film is thermally bonded to:

Aluminum foil (10–20 µm, cathodes) or copper foil (anodes).

Surface treatments (e.g., laser texturing) improve adhesion.

Key parameter: Precise temperature/pressure control to prevent delamination.

5. Final Assembly & Validation

The dry electrodes are:

Slit to required dimensions.

Integrated into battery cells (e.g., stacked or wound).

Validated for conductivity, porosity, and cycling performance.