Microstructure of Graphite-Mo2N Composite Coatings Produced by Solution Precursor Plasma Spray for Supercapacitor Electrodes

High porosity fine grain size graphite-Mo­₂N coatings can be produced by solution precursor plasma spray (SPPS) deposition of MoO₃ followed by a conversion heat treatment. This study examined the parameters of SPPS that had the largest impact on the post-deposition graphite content. More specifically, the following parameters were investigated: the standoff distance, the number of passes, the current, the spray injection system, and the graphite suspension concentration. Upon completion of the SPPS deposition, the microstructure was characterized by scanning electron microscopy and x-ray photoelectron spectroscopy. At short standoff distances, the graphite does not appear to reach the substrate. Conversely, the microstructures produced using a high graphite suspension concentration and a large standoff distance displayed the most graphite content out of all the manufactured electrodes.