Porous Fe2O3 Doped Cathodes for Lithium-Sulfur Batteries

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 electrolytes^1,2 polymer coated sulfur nanosphere core/cell structure³ and conductive mesoporous/nano carbon framework for constraining sulfur have been proposed^4,5. 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 Fe₂O₃ doped sulfur cathode to improve the performance of Li/S batteries. A doping of 5% Fe₂O₃shows improved cycling performance with highly stable reversible discharge capacity of ca. 574 mAh/g after 50 cycles.

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