Advantages of Structure and Electrochemical Properties of Graphene Prepared from Tectonically Deformed Coal

Asa low-cost carbon-richresource, coal has been widelyused toprepare excellent electrochemical energy-storage carbon materialssuch as graphene. However, the different structures of carbon sourcewill affect the performance of carbon materials. To explore the feasibilityof preparing high-performance graphene from the carbon source affectedby tectonic stress in coal, in this paper, series products of coal-basedgraphene are prepared by tectonically deformed coal (TDC) and normalstructural coal (NSC). The structural parameters are characterizedby HRTEM, XRD, Raman, and low-temperature CO2 and N-2 adsorption, and the electrochemical performance of coal-basedgraphene lithium battery is tested by galvanostatic charge-dischargeand cyclic voltammetry. The results show that tectonic stress makesthe proportion of the medium-long aromatic fringes, preferred orientationdegree (POD), and multilayer stacking in TDC aromatic fringes slightlyhigher than those in NSC. At the same temperature, the relativelylarge microcrystalline size, the high order degree, and more porestructures make the local molecular oriented (LMO) domain verticalheight (d) and graphitization degree (G) of the coal-based graphite microcrystalline structure preparedby TDC better than those of NSC, which indicates that the carbon sourcein TDC contains more graphitizable carbon structures. This makes thegraphene prepared by TDC not only possess perfectly ordered crystalplanes but also relatively abundant nanochannels. High lithium-storagecapacity and low charge-transfer resistance make the electrochemicalperformance of graphene prepared by TDC as an anode electrode materialfor lithium-ion batteries superior to that by NSC.