MnO₂-Coated Sulfur-Filled Hollow Carbon Nanosphere-Based Cathode Materials for Enhancing Electrochemical Performance of Li-S Cells

Abstract

When comes to very high energy density energy storage systems, the prospect of lithium-sulfur battery (LSB) technology is very promising. The major problem that prevents the commercial production of LSBs is their poor cycling life caused by the migration of polysulfide intermediates from the cathode structure to the anode. Confining sulfur and the discharged polysulfide intermediates inside conductive porous carbon matrices is regarded as a promising and effective strategy to overcome this problem. In this study, a new class of MnO 2 -coated sulfur-filled hollow carbon nanosphere (HCN)-based cathode materials has been prepared to improve the electrochemical performance of Li-S Cells. The cathode materials constructed with silica nanoparticle hard templates displayed a high initial capacity of 834 mAh g −1 with a capacity fading rate of 0.080% per cycle. This material also showed superior redox kinetics, which enabled the Li-S cells to run at a higher charging-discharging current density.

Enhancement in Electrochemical Performance of Lithium‐Sulfur Cells through Sulfur Encapsulation in Hollow Carbon Nanospheres Coated with Ultra‐Thin Aluminum Fluoride Layer

“…Between cycles 100 and 500, the AlF 3 ‐coated electrode has the excellent capacity retention of 88.9%, in contrast with 83.4% capacity retention for S@HCS. The long‐term cycling data is comparable and even better than the previous results obtained from S@HCS@MnO 2 nanocomposites …”

Synthesis and Electrochemical Properties of Lignin-Derived High Surface Area Carbons

“…Figure 3 shows the result of the TGA analysis used to quantify the amount of infiltrated sulfur in the cathode. We targeted ~60 wt.% of sulfur loading because if too much sulfur was added, it could cover the outer surface of the carbon host and block the flow of Li + ions through the cathode structure [48]. TGA showed that sulfur was completely evaporated from the sample in the range of 150-400 • C in the amount of 63.4% of the mass of the sulfur-carbon composite.…”

Advanced Current Collectors with Carbon Nanofoams for Electrochemically Stable Lithium—Sulfur Cells

“…The hosted active materials then possess smooth charge transfer capabilities and high material stability in the cathode [ 10 , 13 ]. The two main features of the carbon nanofoam, i.e., the conductive matrix that improves the reaction kinetics of sulfur [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ] and the porous network that enhances the electrochemical stability of the polysulfides [ 14 , 15 , 16 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], are optimized by surface coating the carbon nanofoam with a layer of functional coating through chemical vapor deposition. This results in the formation of the graphene-coated and MoS 2 -coated carbon nanofoams that have a nanocoating attached on the carbon nanofoam substrates ( Figure 1 b,c).…”

“…To address these scientific issues, mainstream lithium–sulfur technologies are currently focused on optimizing the sulfur cathode [ 14 , 15 , 16 ] by the addition of conductive additives for high electrochemical utilization [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ] and by the inclusion of porous substrates for strong polysulfide stabilization [ 14 , 15 , 16 , 20 , 21 , 22 , 23 , 24 , 25 ]. One of the most promising methods is the synthesis of sulfur-based nanocomposites that have various conductive and porous substrates and can easily form composites with sulfur.…”