Elemental sulfur was successfully impregnated in an activated carbon (AC) matrix obtained from sisal fibers. The impregnation of sulfur in the activated carbon (S-AC) matrix was confirmed by XRD, SEM and Raman analyses. The sulfurized activated carbon (S-AC) composite electrode was employed as a cathode material for lithium–sulfur (Li–S) cell. The Li–S cell delivered a discharge capacity of 950 mA h g⁻¹ at 0.1C-rate. The electrochemical impedance spectroscopy measurements were carried out for the Li–S cell before and after cycling and also at different depth of discharge and depth of charge. A stable cycling was achieved at 1C-rate.

Hybrid solid polymer electrolytes (HSPE) comprising poly(ethylene oxide) (PEO), LiTFSI, barium titanate (BaTiO₃), and viologen are prepared by a facile hot press. The physical properties of the HSPE membranes are studied by using small-angle and wide-angle X-ray scattering, thermogravimetric analysis, differential scanning calorimetry, and tensile strength. The prepared hybrid solid polymer electrolytes are also investigated by means of ionic conductivity and transport number measurements. The employed analyses collectively reveal that each additive in the PEO host contributes to a specific property: LiTFSI is essential in providing ionic species, while BaTiO₃ and viologen enhance the thermal stability, ionic conductivity, and transport number. The enhanced value in the Li⁺-transport number of HSPE are presumably attributed to the electrostatic attraction of TFSI anions and the positive charges of viologen. Synergistically, the added BaTiO₃ and viologen improve the electrochemical properties of HSPE for the applications in all-solid-state-lithium polymer batteries.

Sodium-ion batteries (SIBs) are promising alternatives to lithium-based energy storage devices for large-scale applications, but conventional lithium-ion battery anode materials do not provide adequate reversible Na-ion storage. In contrast, conversion-based transition metal sulfides have high theoretical capacities and are suitable anode materials for SIBs. Iron sulfide (FeS) is environmentally benign and inexpensive but suffers from low conductivity and sluggish Na-ion diffusion kinetics. In addition, significant volume changes during the sodiation of FeS destroy the electrode structure and shorten the cycle life. Herein, we report the rational design of the FeS/carbon composite, specifically FeS encapsulated within a hierarchically ordered mesoporous carbon prepared via nanocasting using a SBA-15 template with stable cycle life. We evaluated the Na-ion storage properties and found that the parallel 2D mesoporous channels in the resultant FeS/carbon composite enhanced the conductivity, buffered the volume changes, and prevented unwanted side reactions. Further, high-rate Na-ion storage (363.4 mAh g⁻¹ after 500 cycles at 2 A g⁻¹, 132.5 mAh g⁻¹ at 20 A g⁻¹) was achieved, better than that of the bare FeS electrode, indicating the benefit of structural confinement for rapid ion transfer, and demonstrating the excellent electrochemical performance of this anode material at high rates.