Investigation of the characteristics of crushed graphite refined from Yen Bai ore for the purpose of production anodes in redox flow battery systems

Abstract

Graphite is taken from Yen Bai coal mine then crushed and purified to investigate its properties by using measurements such as: Raman shift; TGA–FTIR; BET and SEM. The results show that after grinding graphite for a maximum of 1000 hours in vacuum, a highly reactive carbon will form, which is: capable of chemically absorbing large amounts of carbon dioxide after exposure to air; the area covered by the chemisorbed gas is approximately 40 times larger than the measured BET area, resulting in an increase in actual surface area of ​​∼1175 m².g⁻¹ after 100-1000 h of grinding; Raman spectrum of graphite powder shows that the crystallinity of graphite decreases with grinding time, increasing sp³ bonds diamond-like and fullerene-like in the sample; SEM determined that graphite has a layered structure with a layer thickness of up to 20 nm and a length of 50 nm. Investigating the properties of crushed graphite with such highly reactive properties will be oriented to use in investigating anode fabrication in redox flow battery systems in our near future research.