Enhanced Performance of Lithium Sulfur Batteries with Sulfur Embedded in Sm2O3-Doped Carbon Aerogel as Cathode Material

A Sm 2 O 3 decorated carbon aerogel (CA-Sm) was successfully synthesized through a sol-gel from resorcinol , phloroglucinol (P), formaldehyde and catalyst of oxalic acid and doping compound with Sm 2 O 3 strategies. The small amount of active reactant phloroglucinol promotes synthesis of carbon aerogel (CA) and formation of uniform and porous carbon spheres. The CA-Sm composites present an interlinked porous structure and high specific surface area. The CA-Sm with sulfur loading (CA/S-Sm) from the composite via molten sulfur technique exhibits an enhanced performance with long-term cycling stability and high rate capacity. In particular, the cathode of CA/S-Sm-2 with Sm/C molar ratio of 2/400 achieved a high initial discharge capacity of 1347 and 976   mAh   g −1 at 0.2C and 2C, respectively. And the cathode exhibited a nice long-term cycling stability with a high initial discharge capacity of 1175   mAh   g −1 and maintained 861   mAh   g −1 after 300 cycles at 0.5C. The excellent electrochemical performance of the battery is attributed to interrelated nanospheres , porous carbon structure, large specific surface area of Sm 2 O 3 -doped CA composites and improved electronic and ionic transport at the cathode.