Investigation of NiO/CNF Coating on Glass Fiber Separator as Polysulfide Migration Inhibitors for High-Energy Lithium–Sulfur Batteries

In the current study, nickel oxide (NiO) nanoparticles have been synthesized via sucrose-derived carbon sphere as a soft template derived from the hydrothermal treatment of sucrose. The size of the carbon sphere template is around 2–4 µm, and the derived NiO varied in size between 40 and 100 nm. The derived NiO-coated CNF has been used to coat glass fiber separator which works by effectively blocking and activating the lithium polysulfide thus resulting in the high capacity as well as high Columbic efficiency. The modified NiO/CNF employed cells provided a reversible capacity of 461.11 mAh g−1 along with the high Columbic efficiency of 92% at the end of 50 cycles. The cells also displayed high reversible capacities of 1105.74 mAh g−1, 800 mAh g−1, 603.92 mAh g−1, 415.49 mAh g−1 and 742.9 mAh g−1 at the end of 0.05C, 0.2C, 0.5C, 1C and 0.05C, respectively. The modified separator with its electrostatic interactions of lithium polysulfide with functional groups of CMC binder and electronegative part of NiO nanoparticles combined with the high surface area of carbon nanofibers provides a promising design for developing high-energy lithium–sulfur batteries.