A bimodal porous carbon with high surface area supported selenium cathode for advanced Li–Se batteries

A novel bimodal porous carbon (BPC) with high surface area was prepared by a simple hydrothermal route and KOH activation process , and the Se–BPC composite was synthesized for lithium–selenium batteries by the melt-diffusion method. It is found that the elemental selenium was dispersed inside the pores of BPC based on the analyses. Electrochemical tests reveal that the Se–BPC composite has a large reversible capacity and high rate performance as cathode materials . The Se–BPC (45.1   wt.% Se) composite displays an initial discharge capacity of 552   mAh   g −   1 and a reversible discharge capacity of 264   mAh   g −   1 after 80   cycles at 1   C charge/discharge rate. In particular, the Se–BPC composite presents a durable cycling performance at high rate of 2   C. These outstanding electrochemical features of Se–BPC composite cathode should be attributed to the uniform BPC with high surface area and bimodal porous structure . The bimodal porous carbon would be a promising carbon matrix to develop high performance lithium–selenium batteries.