Preparation And Electrochemical Properties Of Tectonically Deformed Coal-based Alkene

Tectonic coal is the metamorphism product of coal seam being ruptured,deformed,pulverized by geological tectonism.Because most of the tectonic coal mined is powdery coal,how to improve the quality and efficiency of these large number of cheap powdery coal has become an urgent and hard problem.In this paper,a pair of symbiotic tectonic coals（the metamorphic degree of tectonic coals before tectonic movement is the same as that of primary structural coal）and primary structural coals are selected as the comparative research objects.The feasibility of preparing coal-based graphene from Tectonic coal was discussed by means of redox method.TEM,XRD,FT-IR,Raman and other coal structure analysis and testing methods were used to explore the structure of coal-based graphene.The electrochemical performance test methods were used to analyze the storage capacity of lithium ions in tectonic coal-based graphene.The results showed that the preparation of graphene from the studied tectonic coal was feasible,and the performance of the assembled lithium battery was superior.The main results and conclusions are as follows:（1）Tectonic coal can be used for the preparation of coal-based graphene,and the microcrystalline size and order degree of tectonic coal-based graphene are better than those of primary structural coal-based graphene.After high temperature graphitization,coal was used for the preparation of coal-based graphene.Under transmission electron microscopy,it was found that the tectonic coal-based graphene was transparent,and the XRD results showed that the microcrystalline size of tectonic coal-based graphene in Tanjiachong（La=6.672nm,Lc=1.150nm）was larger than that of the primary structural coal-based graphene（La=5.855nm,Lc=1.050nm）.Raman results show that the lattice order of tectonic coal-based graphene（I_D/I_G=0.91）is higher than that of primary structural coal-based graphene（I_D/I_G=1.03）,and the crystal surfaces of graphene prepared from tectonic coal tend to be more perfect.In addition,coal-based graphene prepared at graphitization temperatures of 2600℃and 2400℃,as well as graphene prepared from coal with different sedimentary phases followed the same law.（2）Tanjiachong coal based graphene prepared at graphitization temperature of 2800℃for lithium ion battery anode material has excellent lithium storage performance,the reversible capacity of 200 cycles at the current density of 0.2A.g^-1 reaches 612.8 m Ah.g^-1.It can be maintained at 258.6 m Ah.g^-1 at a high current density of 1.6A.g^-1.Its excellent lithium storage performance is closely related to the large size of microcrystalline,abundant nano-pores,and a moderate amount of Si element on the surface.（3）The electrochemical performance of Tanjiachong coal-based graphene prepared at2600℃is better than Tanjiachong coal-based graphene prepared at 2800℃.The lower reduction graphitization temperature is conducive to energy conservation.In conclusion,it is feasible for tectonic coal to prepare graphene,which provides a broad prospect for the comprehensive utilization of tectonic coal with high extra profit.Compared with the primary structural coal,the structure and electrochemical properties of the tectonic coal-based graphene are better.