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Iowa State University and Ames National Laboratory scientists have discovered a new method for producing synthetic graphite with the use of picosecond pulsed lasers.

 

Synthetic graphite is needed for applications such as electrodes in electric arc furnaces or anodes in lithium-ion batteries. Traditional production relies on carbonization and subsequent graphitization of petroleum products, requiring temperatures of up to 3,000°C. 

Polyimide resin is first dissolved in solvent and solution cast onto a glass substrate. Once cured, the polymer film is subject to picosecond pulsed laser irradiation that induces graphitization. The laser-treated polymer is then heat treated up to 1,000°C in inert environment to remove any non-converted material, yielding a material with a 90% degree of graphitization as verified by Raman, EDS, and XRD characterization.

Beyond polyimide, the process has also been shown to work on the epoxy of recycled printed circuit boards. The synthetic graphite produced from this technology has been shown to work as the battery anode in Li-Ion batteries.

• Lower processing temperature

• Reduced reagent requirements

• Applicable beyond polyimide - effective on the epoxy of recycled printed circuit boards

Synthetic graphite production

Noh et al., "Direct Writing of graphene/graphitic foam through picosecond pulsed laser-induced transformation of soluble polyimide suspension"

Patent(s) applied for