Graphitization of anthracite catalyzed by single metal oxides and its enhanced electrical conductivity

Abstract

ABSTRACT A series of synthetic graphite was fabricated through metal oxide catalytic graphitization using purified anthracite (TYC). The effects of graphitization temperature, catalyst type and its addition methods on structure and properties of graphite products were investigated through the methods of XRD, Raman spectra, SEM, TEM, FTIR and resistivity tester. Increasing graphitization temperature favors the enhancement of order and size of graphite microcrystals, graphitization degree, and conductivity of graphitized products. TiO2 exhibited the best catalytic effects in catalytic graphitization. Compared to directly graphitized TYC at 2800°C (TYC-28), the graphite catalyzed by TiO2 added physically (TYC-28-TiO2) and added chemically (TYC-28-C-TiO2) demonstrated a 13.0 and 16.7% increase in graphitization degree, respectively. Meanwhile, chemical addition method (0.61 × 10−4 Ω·m) outperformed physical addition method (1.21 × 10−4 Ω·m) in improving the electrical conductivity of graphitized products. Moreover, at 2400°C, TYC catalyzed by TiO2 added physically and added chemically presented a graphitization degree of 73.7 and 77.6%, respectively, both exceeding that of TYC-28 (70.7%). Therefore, metallic oxides can enhance the graphitization degree while lowering the required graphitization temperature. This method holds promise for cost-effective and energy-efficient production of high-conductivity graphitized anthracite for batteries, supercapacitors, conductive coatings, and conductive adhesives.