Lychee-like TiO2@TiN dual-function composite material for lithium–sulfur batteries |
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Authors: | Wei Xu Huimei Pang Heliang Zhou Zhixu Jian Riming Hu Yalan Xing Shichao Zhang |
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Institution: | School of Materials Science and Engineering, Beihang University, Beijing 100191 P. R. China, Fax: +861082338148, +861082339319 |
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Abstract: | Lithium–sulfur (Li–S) batteries are promising candidates for next generation rechargeable batteries because of their high energy density of 2600 W h kg−1. However, the insulating nature of sulfur and Li2S, the “shuttle effect” of lithium polysulfides (LiPSs), and the volumetric change of sulfur electrodes limit the practical application of Li–S batteries. Here, lychee-like TiO2@TiN hollow spheres (LTTHS) have been developed that combine the advantages of high adsorption TiO2 and high conductivity TiN to achieve smooth adsorption/spread/conversion of LiPSs and use them as a sulfur host material in Li–S batteries for the first time. The cathode exhibits an initial specific capacity of 1254 mA h g−1 and a reversible capacity of 533 mA h g−1 after 500 cycles at 0.2C, which corresponds to an average coulombic efficiency up to 99%. The cell with the LTTHS@S cathode achieved an extended lifespan of over 1000 cycles. Such good performance can be assigned to the good adsorption and catalysis of the dual-function TiO2@TiN composite. This work proved that the TiO2@TiN composite can be an attractive matrix for sulfur cathodes.Lithium–sulfur (Li–S) batteries are promising candidates for next generation rechargeable batteries because of their high energy density of 2600 W h kg−1. |
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