Encapsulation of S/SWNT with PANI web for enhanced rate and cycle performance in lithium sulfur batteries.

ABSTRACT: Lithium-sulfur batteries show great potential to compete with lithium-ion batteries due to the fact that sulfur can deliver a high theoretical capacity of 1672?mAh/g and a high theoretical energy density of 2500?Wh/kg. But it has several problems to be solved in order to achieve high sulfur utilization with high Coulombic efficiency and long cycle life of Li-S batteries. These problems are mainly caused by the dissoluble polysulfide species, which are a series of complex reduced sulfur products, associating with shuttle effect between electrodes as well as side reactions on lithium metal anode. To alleviate these challenges, we developed a sulfur-carbon nanotube (S/SWNT) composite coated with polyaniline (PANI) polymer as polysulfide block to achieve high sulfur utilization, high Coulombic efficiency, and long cycle life. The PANI coated S/SWNT composite showed a superior specific capacity of 1011?mAh/g over 100 cycles and a good rate retention, demonstrating the synergic contribution of porous carbon and conducting polymer protection to address challenges underlying sulfur cathode.

SUBMITTER: Kim JH 

PROVIDER: S-EPMC4354035 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature