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 potous carbon would be a promising carbon matrix to develop high performance lithium-selenium batteries. (C) 2015 Elsevier B.V. All rights reserved.