Hierarchical hydrogenated TiO2 spheres (HTSs) constructed by ultrathin nanosheets of highly exposed (001) facet are smartly designed, and fabricated after hydrogenation in H2 atmosphere. They are then further utilised as an efficient encapsulating host for sulfur species, benefiting from its inherently appealing merits required for advanced S cathodes.

A multidisciplinary team, which includes researchers from Anhui University of Technology, and Xiamen University in China, carry out systematical experimental measurements and theoretical calculations. The researchers find a distinct interaction of the Sn4- with different crystal planes including fresh and reduced (001), and (101) facets. The hybrid S/HTSs cathode exhibits high Coulombic efficiency, exceptional long cycling performance, and large reversible capacity at high C rates. This is thanks to better electronic conductivity, smaller charge transfer resistance and stronger chemical bonding between Sn2- and reduced (001) facet of HTSs.

In-depth understandings of the intrinsic physicochemical mechanism involved in the enhanced electrochemical properties of hybrid S/HTSs favour future rational design and purposeful fabrication of other metal oxide-based matrixes with specific exposed crystalline facets as attractive hosts for high-performance LSBs.

More information about this research can be found in the journal Nanotechnology 04 045403.

Further reading

Lithium ion batteries: nanostructured composites improve storage properties (Apr 2014)
Li-ion batteries benefit from hierarchical LiFePO4/C (Nov 2012)
Etched holes increase speed of graphene electrodes (Jun 2015)