Effects of Temperature and Gas Atmosphere during Coal Tar Pitch Emulsification on The Characteristics of Mesocarbon Microbeads (MCMB) as Battery Anode Precursor

Mesocarbon microbeads (MCMB) are spherical carbon materials characterized by their high crystallinity and excellent electrochemical properties, making them attractive for energy storage applications. This study investigates the effects of temperature and gas atmosphere during coal tar pitch (CTP) emulsification on the characteristics of MCMB as precursors for battery anodes. Coal tar (CT) was distilled under vacuum and atmospheric conditions to produce CTP-V and CTP-A, respectively. The pitches were characterized for ash, quinoline insolubles (QI), toluene insolubles (TI), softening point, and ultimate composition. Emulsification was performed by mixing CTP with silicone oil, heating at 290 °C or 360 °C under air, N2, or CO2 flow, followed by mesophase (MP) separation and carbonization at 900 °C to obtain MCMB. Results showed that CTP-V, with a higher softening point (151 °C) and QI (5.02%), was more suitable for MCMB synthesis than CTP-A, although its high TI content contributed to irregular morphologies. Increasing the emulsification temperature in N2 and CO2 atmospheres improved carbon crystallinity and produced larger MCMB particles, while air at 360 °C prevented MCMB formation due to crosslinking reactions. The most promising sample (M-290A) exhibited improved crystallinity (Lc = 2.178 nm, N = 7.148).