Different bulk structures of graphite oxide were systematically investigated using density functional theory (DFT). Our model consisted of a hexagonal in-plane structure of graphene with hydroxyl and epoxide groups, and different oxidation levels and water content. The graphitic AB stacking order was stable in anhydrous graphite oxide, independent of oxidation levels. The hydrogen bonding inter...

Fine-grained isotropic graphite is the material of choice for the production target and the beam catchers at the planned Super-FRS fragment separator at FAIR. Heavyion irradiation studies of graphite are needed, as radiation damage will ultimately limit the lifetime of these components. Polycrystalline graphite and highly-oriented pyrolytic graphite (HOPG) were irradiated with energetic ions an...

Boron strongly modifies electronic and diffusion properties of graphite. We report the first ab initio study of boron interaction with the point defects in graphite, which includes structures, thermodynamics, and diffusion. A number of possible diffusion mechanisms of boron in graphite are suggested. We conclude that boron diffuses in graphite by a kick-out mechanism. This mechanism explains th...

Graphite is an excellent material for bipolar plates used in Proton Exchange Membrane (PEM) fuel cell due to its great chemical resistance, but the brittle nature makes it difficult to manufacture. Selective Laser Sintering (SLS) based on layer-by-layer manufacturing technology can fabricate graphite bipolar plates with complex gas flow channels. To improve the performance of bipolar plates inc...

Electrochemical impedance spectroscopy, EIS, has been applied for characterization of electrochemically modified graphite electrodes in the sulphuric acid solution. Graphite modifications were performed by potential cyclization between potentials of graphite oxide formation/reduction, different number of cycles, and prolonged reduction steps after cyclization. Impedance spectra measured at two ...

We report the synthesis of tubular graphite cones using a chemical vapor deposition method. The cones have nanometer-sized tips, micrometer-sized roots, and hollow interiors with a diameter ranging from about 2 to several tens of nanometers. The cones are composed of cylindrical graphite sheets; a continuous shortening of the graphite layers from the interior to the exterior makes them cone-sha...

Selective Laser Sintering (SLS) provides a way to fabricate graphite composite bipolar plates, which significantly reduces time and cost at the research and development stage of bipolar plates, as compared with the conventional fabrication methods of compression molding and injection molding. Different graphite materials (natural graphite, synthetic graphite, carbon black, and carbon fiber) wer...

Over the history of carbon, it is generally acknowledged that Bernal AB stacking of the sp2 carbon layers is the unique crystalline form of graphite. The universal graphite structure is synthesized at 2,600~3,000 °C and exhibits a micro-polycrystalline feature. In this paper, we provide evidence for a metastable form of graphite with an AA' structure. The non-Bernal AA' allotrope of graphite is...

Lithium evaporation treatments in the National Spherical Torus Experiment (NSTX) have shown dramatic improvements in plasma performance increasing the viability of lithium as a Plasma Facing Component (PFC) material. In order to understand the complex system of lithiated ATJ graphite, chemical sputtering measurements of plain and lithiated ATJ graphite are conducted in our upgraded IIAX (Ion Su...

The basal plane cleavage energy (CE) of graphite is a key material parameter for understanding many of the unusual properties of graphite, graphene and carbon nanotubes. Nonetheless, a wide range of values for the CE has been reported and no consensus has yet emerged. Here we report the first direct, accurate experimental measurement of the CE of graphite using a novel method based on the self-...