Resumen
A novel technique to prepare carbon/sulfur composites as cathode materials for Li/S batteries is proposed, which we call the ?solution evaporation concentration crystallization? method. Three composites with different S loadings were prepared, subject to two different solvent evaporation rates from acetylene black (AB)/sulfur in carbon disulfide solutions. X-ray diffraction, environmental scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller measurements all show that the porous AB structure is well-filled with S. Composites prepared at a lower solvent evaporation rate with 50 wt % S content, had good electrochemical properties, with 1609.67 mAh g-1 after 100 cycles. Composites with better dispersibility at a low solvent evaporation rate can effectively prevent polysulfide from dissolving in the electrolyte, and serve to stabilize the structure of the S cathode during the charge-discharge process.