Lithium-sulfur (Li/S) battery is a promising electrochemical system that has the possibility to achieve high-energy (theoretical capacity of 1675 mAh/g). However, the system suffers from several drawbacks including dissolution of intermediate polysulphide reaction species into electrolyte. In response to this challenge, novel advances in materials design such as new electrolytes1,2
polymer coated sulfur nanosphere core/cell structure3
and conductive mesoporous/nano carbon framework for constraining sulfur have been proposed4,5
. These techniques significantly improve the cycling performance of Li/S batteries but falls short of completely controlling polysulphide dissolution. Recently, a new concept of embedding small fraction of porous silica particles (SBA-15) within carbon-sulfur nanocomposites and acted as an internal polysulfide reservoir has been proposed by Nazar et al. to stabilize the system6
. In line with this concept, here we report the use of porous Fe2
doped sulfur cathode to improve the performance of Li/S batteries. A doping of 5% Fe2
shows improved cycling performance with highly stable reversible discharge capacity of ca. 574 mAh/g after 50 cycles.
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(2) Wang, J.; Chew, S. Y.; Zhao, Z. W.; Ashraf, S.; Wexler, D.; Chen, J.; Ng, S. H.; Chou, S. L.; Liu, H. K. Carbon 2008, 46, 229.
(3) Li, W. Y.; Zheng, G. Y.; Yang, Y.; Seh, Z. W.; Liu, N.; Cui, Y. P Natl Acad Sci USA 2013, 110, 7148.
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