Efficient Polysulfides Conversion Kinetics Enabled by Ni@CNF Interlayer for Lithium Sulfur Batteries

Abstract

Recent advances in the development of lithium-sulfur batteries (Li-S) demonstrated their high effectiveness owing to their tremendous theoretical specific capacity and high theoretical gravimetrical energy. Nevertheless, the potential commercialization of Li-S is significantly held by the insulating nature of sulfur and complicated RedOx reactions during the electrochemical charge-discharge processes. This paper presents nickel nanoparticles embedded carbon nanofibers interlayer (Ni@CNF) between a cathode and a separator as an additional physical barrier against lithium polysulfides shuttle for their efficient conversion during the charge-discharge cycling. Furthermore, the interlayer provides an auxiliary electron pathway with subsequent lowering of the charge transfer resistance. The electrochemical analysis of a Li-S cell with the Ni@CNF interlayer demonstrated high initial discharge capacities of 1441.2 mAh g-1 and 1194.2 mAh g-1 at 0.1 and 1.0 C rates, respectively, with remarkable capacity retention of ~83% after 100 cycles. This study revealed the advantageous impact of Ni@CNF towards solving the major issues of lithium-sulfur batteries, i.e., sluggish kinetics and the shuttle effect.