The lithium-sulphur battery relies on the reversible conversion between sulphur and ​Li₂S and is highly appealing for energy storage owing to its low cost and high energy density. Porous ​carbonsare typically used as sulfur hosts, but they do not adsorb the hydrophilic polysulphide intermediates or adhere well to ​Li₂S, resulting in pronounced capacity fading. Here we report a different strategy based on an inherently polar, high surface area metallic oxide cathode host and show that it mitigates polysulphide dissolution by forming an excellent interface with ​Li₂S. Complementary physical and electrochemical probes demonstrate strong polysulphide/​Li₂S binding with this ‘sulphiphilic’ host and provide experimental evidence for surface-mediated redox chemistry. In a lithium-sulphur cell, Ti₄O₇/​S cathodes provide a discharge capacity of 1,070 mAh g⁻¹ at intermediate rates and a doubling in capacity retention with respect to a typical conductive ​carbonelectrode, at practical sulphur mass fractions up to 70 wt%. Stable cycling performance is demonstrated at high rates over 500 cycles.

http://www.nature.com/ncomms/2014/140826/ncomms5759/full/ncomms5759.html

Nature Communications 5, Article number: 4759 doi:10.1038/ncomms5759