ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Enhancing lithium–sulphur battery performance by copper oxide@graphene oxide nanocomposite-modified cathode

Seyyed Taher Seyyedin, Mohammad Reza Sovizi, and Mohammad Reza Yaftian

Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, University of Zanjan, 45371-38791, Zanjan, Iran (Islamic Republic of)

E-mail: mrsovizi@yahoo.com

Abstract: Nanosheet structures of copper oxide@graphene oxide (CuO@GO) composite were developed as a host material to embed sulphur nanoparticles for use as cathodes in lithium–sulphur (Li-S) batteries. The homogeneous immobilisation of sulphur in the conductive matrix of CuO@GO within a strong chemical bond between carbon and polysulphide intermediates through the Lewis acid function of CuO provides a high specific discharge capacity of the CuO@GO/S electrode in comparison with the GO/S nanocomposite. The CuO@GO/S cathode delivers a discharge capacity of 1048.95 mA h g^-1, 841.74 mA h g^-1, 736.49 mA h g^-1, 695.17 mA h g^-1, 643.86 mA h g^-1, and 457.08 mA h g^-1 at different current rates of 0.1 C, 0.4 C, 0.7 C, 0.8 C, 1 C, and 2 C, respectively. The application of CuO@GO/S maintains the average coulombic efficiency of 96 % after 300 cycles at 1 C rate with a capacity retention of approximately 55.8 %. The rapid ion transportation within the efficient physicochemical confinement of polysulphides confirmed the role of the CuO@GO/S nanocomposite as a promising cathode material for the next generation of high-energy density Li-S batteries.

Keywords: lithium–sulphur battery; nanocomposite; sheet-like structures; metal oxide; sulphur cathode

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0088

Chemical Papers 70 (12) 1590–1599 (2016)