The insulating nature and complex redox reaction of elemental sulfur mandates their encapsulation inside an electronic conductor such as carbon. We discuss here a sulfur/microporous carbon aerogel (S/CA) composite as an efficient, low-cost, high-performance cathode for rechargeable lithium-sulfur (Li/S) battery. The S/CA cathode with varying ratios of sulfur:CA is prepared using pressure induced melt diffusion technique. Of the four different ratios, (sulfur:CA= 70:30) exhibited the best performance. The Li/S cell with (sulfur:CA= 70:30) cathode shows a first discharge capacity of 1308 mAhg ^-1 at a current rate C/10 and the cell is stable up to 300 cycles with a discharge capacity ≈750 mAhg ^-1. This composition also exhibits good rate capability over the current density range (0.1-2)C. Post cycling UV-Visible absorbance spectroscopy is carried out to ascertain the dissolution of lithium polysulfides in various S/CA cathodes. UV-Visible results confirm that among the various sulfur:CA compositions, the one with the (sulfur:CA= 70:30) has the optimum retention of polysulfides leading to a superior Li/S battery performance.