Continuous synthesis of graphite with tunable interlayer distance

Abstract

A study was carried out to produce graphite with controlled interlayer distance synthesized from methane using hydrogen as modifying agent. The synthesis was carried out in radio frequency (r.f.) thermal plasma where the methane-to-hydrogen ratio varied systematically over a wide range. The synthesized materials were investigated in terms of structure, morphology and the interlayer distance. It is found that there is a critical fraction of hydrogen, around half of that of methane flow rate, up to which it is possible to control the interlayer distance as well as the number of layers making up the platelet in the synthesized material. The number of layers which were around 25 in the granular graphite obtained with methane only was modified into a flaky graphite of 10 mu m in size with as few as 12 layers yielding a surface area of 300 m(2)/g. The result combined with data from literature show that it is possible to adjust the interlayer distance in graphite from Lc = 0.334 to 0.369 nm even up to 0.416 nm. The significance of this was discussed within the context of the use of graphite as anode in rechargeable batteries.