Zhang Hang, Zhang Yugui, Li Jian, Ma Zhangnan
School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, P.R. China.
State Key Laboratory Cultivation Base for Gas Geology and Gas Control of Henan Province, Jiaozuo 454003, P.R. China.
ACS Omega. 2023 Jul 3;8(28):25142-25154. doi: 10.1021/acsomega.3c02073. eCollection 2023 Jul 18.
Asa low-cost carbon-rich resource, coal has been widely used to prepare excellent electrochemical energy-storage carbon materials such as graphene. However, the different structures of carbon source will affect the performance of carbon materials. To explore the feasibility of preparing high-performance graphene from the carbon source affected by tectonic stress in coal, in this paper, series products of coal-based graphene are prepared by tectonically deformed coal (TDC) and normal structural coal (NSC). The structural parameters are characterized by HRTEM, XRD, Raman, and low-temperature CO and N adsorption, and the electrochemical performance of coal-based graphene lithium battery is tested by galvanostatic charge-discharge and cyclic voltammetry. The results show that tectonic stress makes the proportion of the medium-long aromatic fringes, preferred orientation degree (POD), and multilayer stacking in TDC aromatic fringes slightly higher than those in NSC. At the same temperature, the relatively large microcrystalline size, the high order degree, and more pore structures make the local molecular oriented (LMO) domain vertical height () and graphitization degree () of the coal-based graphite microcrystalline structure prepared by TDC better than those of NSC, which indicates that the carbon source in TDC contains more graphitizable carbon structures. This makes the graphene prepared by TDC not only possess perfectly ordered crystal planes but also relatively abundant nanochannels. High lithium-storage capacity and low charge-transfer resistance make the electrochemical performance of graphene prepared by TDC as an anode electrode material for lithium-ion batteries superior to that by NSC.
作为一种低成本的富碳资源,煤炭已被广泛用于制备石墨烯等优异的电化学储能碳材料。然而,碳源结构的差异会影响碳材料的性能。为探究利用受构造应力影响的煤炭碳源制备高性能石墨烯的可行性,本文采用构造变形煤(TDC)和正常结构煤(NSC)制备了系列煤基石墨烯产品。通过高分辨透射电子显微镜(HRTEM)、X射线衍射(XRD)、拉曼光谱以及低温CO和N吸附对结构参数进行表征,并采用恒电流充放电和循环伏安法测试了煤基石墨烯锂电池的电化学性能。结果表明,构造应力使TDC芳香条纹中的中长芳香条纹比例、择优取向度(POD)以及多层堆叠略高于NSC。在相同温度下,相对较大的微晶尺寸、较高的有序度以及更多的孔隙结构使得TDC制备的煤基石墨微晶结构的局部分子取向(LMO)域垂直高度()和石墨化程度()优于NSC,这表明TDC中的碳源含有更多可石墨化的碳结构。这使得TDC制备的石墨烯不仅具有完美有序的晶面,还具有相对丰富的纳米通道。高储锂容量和低电荷转移电阻使得TDC制备的石墨烯作为锂离子电池负极材料的电化学性能优于NSC。