Abstract:
The development of new carbon nanomaterials from coal has great application potential in enhancing the electrochemical performance of transition metal oxides to fabricate electrode materials for lithium-ion batteries (LIBs) with high specific capacity and high stability.Herein,the coal-based graphene oxide (CGO) was developed through a combined strategy of high temperature graphitization and chemical oxidation using Taixi anthracite as a carbon precursor,and then the coal-based graphene/ferric oxide (CG/Fe2O3) structures were constructed via electrochemical deposition method with nickel foam as substrate.With the composites directly served as a free-standing anode of LIBs,the high reversible capacity of 1156 mAh/g can be achieved at a high current density of 1.0 A/g,and the capacity retention is 88.9%,when the current density is increased to 5.0 A/g,the capacity can still be maintained at about 1 074 mAh/g,showing a better rate performance and cycling stability than Fe2O3.The analysis of the charge storage mechanism shows that the capacitance of the CG/Fe2O3-1 is mainly contributed by the electric double-layer capacitance generated by CG and the pseudocapacitance generated by the Fe2O3 redox reaction during the charging and discharging process.The remarkable lithium storage capacity of CG/Fe2O3 can be ascribed to the exquisite design of three-dimensional hierarchical architecture,which endows it with a highly interpenetrated porous conductive network and more stable spatial structure,provide more accessible electrode/electrolyte interfaces for effective Li+ and charge transport,accelerating the kinetics of lithiation/delithiation.Overall,the present study provides a useful insight into the development of coal-based graphene composites used as advanced electrode materials for LIBs.