Carbon nanofiber–sulfur composite cathode materials with different binders for secondary Li/S cells

Abstract

A sulfur-coated carbon nanofiber (CNF–S) composite cathode material was prepared by a chemical deposition method in an aqueous solution. This CNF–S material was evaluated as the cathode material in lithium/sulfur cells with three different binders. The results of the SEM and TGA measurements reveal that CNF–S has a typical core–shell structure, containing 75.7 w/o sulfur coated uniformly on the surface of the CNFs. The effects of different binders on the potential profiles, electrode capacity and capacity retention with cycling were investigated. The electrode prepared with CMC+SBR binder has the best performance compared with PVdF and PEO binders, exhibiting a specific capacity of up to 1313mAhg−1S at the initial discharge and a specific capacity of 586mAhg−1S after 60 cycles.