All solid-state room-temperature lithium-sulfur (Li-S) batteries have gained increasing attention due to their ability to eliminate the polysulfides shuttle effects and the safety dangers associated with the liquid electrolytes. Herein, a novel composite solid-state electrolyte, which is nickel-tungsten carbides (NiWC) over mesoporous silica (SBA-15) filled polyethylene oxide (PEO), was developed and investigated for Li-S batteries. The filler minimizes the crystallinity of the PEO and increases the ionic conductivity of the electrolyte, resulting in lowering the AC impedance of electrolyte composite from 26,256 ohm to 2416 ohm and to 5734 ohm after adding the electrolyte material with Ni/W ratios of 1:1 and 9:1, respectively. A high initial specific capacity of 1305 mAh g⁻¹ and a capacity retention of 66.7% after 8 cycles at C/10 was obtained at room temperature after adding NiWC/SBA-15 with a Ni/W ratio of 1:1. This novel composite solid-state electrolyte shows a remarkable long-term performance at high current rates (1, 2, 4, and 5C) and rate capabilities at 0.1, 0.2, 0.5, 1, 2, 4 and back to 0.1C. The battery was able to recover 77% of the initial specific capacity at 0.1C. The materials were characterized by XRD and SEM-EDX to study the crystallinity and elemental distributions, respectively.

Lithium–sulfur batteries suffer from a reduced cycle life and diminished coulombic efficiency, which is attributed to the polysulfide shuttle effect. We herein present a process for the fabrication of lithium–sulfur battery cathode material via the recrystallization of dissolved sulfur inside self-assembled carbon nanospheres synthesized through the carbonization of d-glucose. Trapping sulfur in the carbonaceous matrix lessens the rapid dissolution of polysulfides and minimizes the loss of active sulfur, thus extending the cycling stability of these batteries. The carbon–sulfur composite material was characterized via X-ray diffraction (XRD), field emission scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Electrochemical analysis of the material and its functionality as an electrode for lithium–sulfur battery systems was evaluated in a coin cell format using impedance spectroscopy and a life cycle study. The as-prepared cathode has shown remarkable electrochemical performance with a specific capacity of 781 mA/g at 0.1 C after 500 charge/discharge cycles and 83.4% capacity retention.