Synthesis and characterization of porous monodisperse carbon spheres/selenium composite for high-performance rechargeable Li-Se batteries

In order to find the appropriate material to load selenium for higher performance of rechargeable Li-Se batteries, the resorcinol-formaldehyde resins derived monodisperse carbon spheres (RFCS)/Se composites were fabricated by the melting- diffusion method. The RFCS were obtained from initial carbonization of resorcinol-formaldehyde resins and subsequent KOH activation. Three kinds of samples of the RFCS/Se composites with different mass ratios were characterized by XRD, Raman spectroscopy, SEM, BET and EDS tests, which demonstrate that the samples with diverse mass fractions of selenium have distinct interior structure. The most suitable RFCS/Se composite is found to be the RFCS/Se-50 composite, which delivers a high reversible capacity of 643.9 mA center dot h/g after 100 cycles at current density of 0.2C.