Stoichiometric Study on Magnesium and Cerium Curling Effect of DPG’s Derivatives : Carbon Nanotubes and Fullerenes

DPG artificial graphite which precipitated from molten cast iron is a novel method to produce carbon nanotubes and fullerenes owing to boron-triggering machanochemical effect and chlorine ion doping effect proposed in our previous study. Magnesium oxide and cerium dioxide added into the process to enhance the curling effect by circumferential growth mode of graphene sheets. BET specific surface area data shows indirect evidence of increase of carbon nanotubes and fullerenes. And tubular microstructures in nanoscale of graphite are also confirmed in SEM microscopy observation.

C60 and CNT-containing DPG applied on anodic active material of lithium ion secondary batteries. Most samples first charging capacity show the amaaing capacities over 1000 mAh/g which exceed much more than the sample without MgO in the DPG process. Similar situation was also discoverd in CeO2 system. Besides, ICP-MS results proved that the structural influence in nano-scale is the most probable reason to cause the great promotion of first charging capacity of lithium ion secondary battery.

Furthermore, peaks at around 410-450°C in DTA curves are attributed to the decomposition of CNT in air atmosphere. The calculation of peak area could be a possible method to evaluate the content of CNT in DPG directly. The maximum value of peak area is corresponded with the minimum value of graphitization dgree and maximum value of Raman R ratio whether in MgO sytem or in CeO2 system. Therefore, there might be some relationship between the effet of MgO or CeO2 addition and the special nano-scale structure formation in DPG.