电池技术手册5

Coating process
 Process equipment
 Quality control
 Key control points

Coating and slurry delivery system
Film quality control
 Uniformity (Thickness, weight/area)
 Film impedance
 Pull strength
 Appearance
 Film dryness

Factors to film uniformity
 Stability of slurry delivery speed.
 Stability of Mylar speed.
 Slurry pressure inside slot die
 Slot die size: width, thickness, gap, chamber.
 Slurry particle size distribution.
 Slurry property: Viscosity, density, stability, etc.
 Others

How can we obtain desired film
 Well-mixed slurry with desired particle size distribution.
 Digital motor for precision gear pump.
 Precision service motor for Mylar rolling.
 Slot die size: width, thickness, gap, chamber.
 Stirring the slurry to guarantee its stability.
Real time monitor the pressure inside the slot die.
 Real time monitor film thickness

An example of uniformity control















Conclusion
 Special mixing workheads and procedures to obtain desired mixing slurry with ideal particle size distribution, which is very important for the coating quality and product performance.
 Systematic process control to obtain a perfect film quality, especially the uniformity.







第三章 包装基本知识
Content
Material status
- Foil melting temp(DSC)
- Sealant melting temp(DSC)
- Suitable sealing temp range
Top sealing conflict
- Different temp curve: foil-sealant and foil-foil

• Rubber: Poor heat conductive

Solution and evaluation result
- Bare battery heating or tab heating
- Evaluation result

I. Material status
Foil & sealant DSC






II. Top sealing conflict

1. Different temp curve at different area

- Foil-foil is easy to be melt and sealed

• Foil-sealant need more heat to be melt

1. Root cause

- Bare battery will absorb amount of heat
- Poor heat conductive of rubber

1. Peel strength compare

- Foil-foil can be sealed from 180deg/0.4Mpa/2s
- Foil-sealant(rubber side) has no strength even 190deg/0.4Mpa/4s






III. Solution

1. Resolve method

- Bare battery heating or tab heating