Roll-to-Roll Gravure Coating of PVDF on a Battery Separator for the Enhancement of Thermal Stability.

The polyethylene lithium-ion battery separator is coated with a polymer by means of a roll-to-roll (R2R) gravure coating scheme to enhance the thermal stability. The polyvinylidene fluoride (PVDF) or polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) is gravure-coated, and the pores are fabricated based on online nonsolvent-induced phase separation (NIPS). N-methylpyrrolidone is used as a solvent, and deionized water or a methanol mixture thereof is exploited as a nonsolvent in NIPS. Scanning electron microscopy confirms that the polymer film is formed and that the pores are well developed. The thermal shrinkage decreased by 20.0% and 23.2% compared to that of the bare separator due to the coating of PVDF and PVDF-HFP, respectively. The R2R gravure coating scheme is proven to be fully functional to tailor the properties of lithium-ion battery separators.

A review on intense pulsed light process as post-treatment for metal oxide thin films and nanostructures for device application.

The intense pulsed light (IPL) post-treatment process has attracted great attention in the device fabrication due to its versatility and rapidity particularly for solution process functional structures in devices, flexible/printed electronics, and continuous manufacturing process. The metal oxide materials inherently have multi-functionality and have been widely used in form of thin films or nanostructures in device application such as thin film transistors, light emitting diodes, solar cells, supercapacitors, etc. The IPL treatment enhances the physical and/or chemical properties of the functional metal oxide through photothermal effects. However, most metal oxides are transparent to most range of visible light and require more energy for post-treatment. In this review, we have summarized the IPL post-treatment processes for metal oxide thin films and nanostructures in device applications. The sintering and annealing of metal oxides using IPL improved the device performances by employing additional light absorbing layer or back-reflector. The IPL process becomes an innovative versatile post-treatment process in conjunction with multi-functional metal oxides in near-future device applications.