Sulfur-doped porous carbon derived by metal-organic framework (MOF-5) for high lithium/sodium storage performance

Metal-organic framework (MOF-5) material was synthesized by solvothermal method. Porous carbon (C) and sulfur-doped porous carbon (S/C) were fabricated by calcining and vulcanization of MOF-5. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Raman spectroscopy were used to characterize the crystal structure and morphology of the samples. The electrochemical performance of C and S/C materials were tested as anode materials for lithium ion batteries (LIBs) and sodium ion batteries (SIBs). The S/C exhibits the high reversible capacity (1114.8 mAh g−1 after 100 cycles at 0.1 A g−1 and 485 mAh g−1 after 500 cycles at 2.0 A g−1), as anode for LIBs. It behaves a reversible discharge capacity of 268.8 mAh g−1 after 100 cycles at 0.1 A g−1 and a capacity of 157 mAh g−1 after 1000 cycles at 2.0 A g−1, as anode for SIBs. Compared with C, the electrochamical performance of S/C material is significantly improved. This is mainly because the bigger specific surface area and the doping of sulfur atoms increases the layer spacing and facilitates the kinetics of the intercalation and deintercalation of Li+ and Na+ ions, especially Na+ ions.