UV Curable Separator Coatings

What is a Li-ion Battery Separator? – The separator serves a very important function in the Li-ion battery in terms of safety. It acts as a barrier to isolate, or separate, the anode and cathode to prevent them from making electrical contact with each other. If the separator shrinks due to thermal events, the anode and cathode will make electrical contact which can result in a fire. The thermal stability of Li-ion Battery Separators is enhanced by applying a ceramic coating to the separator film. Applying a ceramic coating on one side will raise the temperature stability however, coating on both sides provides the highest possible temperature rating.

Conventional Technology Challenge: Uncoated separators rapidly shrink when the temperature in the battery elevates causing fires. Ceramic coated separators, which are designed to operate at higher battery temperatures, are costly to manufacture because they require long, slow drying ovens that utilize a significant amount of energy.

The Miltec UV Solution: Miltec UV’s proprietary process involves the use of high-powered UV light to instantly cure the ceramic coating applied to the separator film. Miltec manufacturers a UV Light curable binder for the ceramic coating on separators. Our process replaces conventional binders with UV light curable binders. This eliminates the need for slow, energy intensive thermal drying and will save separator manufacturers time, space, and money.

Miltec’s UV technology coats the separator with a ceramic coating that acts as an electrical insulator. The industry standard kiss gravure coating process is used to apply a ceramic coating to separator film. Water is flashed off in a small IR dryer while the film temperature is maintained by a chill roll. The ceramic coating is cured instantly under the UV lamp.

Benefits of UV Ceramic Coated Separator

  • Reduction in Separator Manufacturing Costs
  • Reduced Energy Consumption
  • Faster Line Speeds
  • Lower Carbon Footprint
  • Improved Safety
  • Short Drying Oven
  • Improved Battery Performance
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