A novel molecular synthesis route to Li2S loaded carbon fibers for lithium–sulfur batteries

Abstract

The synthesis of a novel air-stable molecular precursor (LiSC₂H₄)₂NMe enables the formation of the desired 1D lithium sulfide (Li₂S) via the electrospinning method under ambient conditions. The solubility of the precursor in polar solvents combined with a common polymer (PVP) allowed a suitable spinning solution to obtain ideal green Li₂S loaded fibers. 3D fiber mats of the calcined homogeneous 1D electrospun Li₂S/C fibers were characterized by electron microscopy and X-ray powder diffraction analysis. Direct integration of Li₂S in an electronically conductive carbon matrix as the cathode obviates the need of elemental lithium as the anode, which is a great advantage against the reported lithium–sulfur batteries. An initial capacity of about 870 mA h g⁻¹ at C/20, a capacity retention of 73% after 100 cycles at C/10 and a capacity of about 400 mA h g⁻¹ at 1C were observed for the presented system.