Rational Synthesis of Fern Leaf-like FeS₂@Sulfur-Doped Carbon as an Anode for Superior Lithium-Ion Batteries

Abstract

Fern leaf-like FeS2@sulfur-doped carbon (SC) composites are synthesized through a sulfuration process using fern leaf-like γ-Fe2O3@C as the raw material. The design of combining fern leaf-like FeS2 with SC layers is favorable to enhancing the electronic conductivity of FeS2 and buffering the severe volume change associated with the pulverization issue that exists in most metal sulfide-based electrodes. When the fern leaf-like FeS2@SC composite serves as an anode for lithium-ion batteries, it can deliver high first discharge capacities of 1656.6 and 1364.7 mA h g–1 at a low density of 0.1 A g–1 and a high current density of 5 A g–1. Besides, benefiting from the structural advantages, the FeS2@SC composite shows superior rate capability (442.5 mA h g–1 at 5 A g–1) and cyclability (848.9 mA h g–1 at 1 A g–1 after 300 cycles, corresponding to 89.14% of the second discharge specific capacity). The enhanced electrochemical performance of FeS2@SC can be ascribed to the synergistic effect of the hierarchical fern leaf-like FeS2 microstructure and the sulfur-doped carbon coating layer.

Progress of transition metal sulfides used as lithium-ion battery anodes

“…can effectively enhance the interface stability, electronic conductivity, and lithium-ion diffusion kinetics. 39,40 Carbon materials are often used as the coating of FeS 2 because of excellent conductivity. The carbon-coated FeS 2 composite material were synthesized via the solid-phase method by Zhang et al 41 The carbon coating can reduce the corrosion of active materials by HF, slow down the dissolution of sulfides, and improve the cycle performance of FeS 2 .…”

Perspective of Vanadium Disulfide: A Rising Star Finds Plenty of Room in Single and Multielectron Energy Storage

“…Inorganic Materials. Integrating two different twodimensional materials enables forming heterostructures and achieving strong interaction between different material interfaces, 84,193 while maintaining the advantages of the twodimensional structures, eliminating the related disadvantages, and providing an opportunity to construct high-performance electrodes. 194 More recently, the unique two-dimensional stacked nanosheet VS 2 /MoS 2 heterostructure was synthesized.…”

Overview of the Latest Developments and Perspectives about Noncarbon Sulfur Host Materials for High Performance Lithium–Sulfur Batteries

“…Also, the Coulombic efficiency is low, and the self-discharge phenomenon is serious. Third, during the charge and discharge process, LiPSs will diffuse to the lithium anode, and parts of the long-chain LiPSs can be reduced to short-chain LiPSs and re-enter the cathode electrode under the action of the electric field to convert into long-chain LiPSs . The phenomenon is called the “shuttle effect”. ,, On the one hand, this phenomenon will cause the uneven distribution of elemental sulfur on the surface of the cathode, which will cause serious passivation to increase the internal impedance of the batteries .…”

“…Third, during the charge and discharge process, LiPSs will diffuse to the lithium anode, and parts of the long-chain LiPSs can be reduced to short-chain LiPSs and re-enter the cathode electrode under the action of the electric field to convert into long-chain LiPSs . The phenomenon is called the “shuttle effect”. ,, On the one hand, this phenomenon will cause the uneven distribution of elemental sulfur on the surface of the cathode, which will cause serious passivation to increase the internal impedance of the batteries . On the other hand, long-chain LiPSs will diffuse to the lithium anode and react with them to form short-chain LiPSs covering the surface of the lithium sheet, thereby hindering the diffusion of lithium ions. , …”

“…5,9,23 On the one hand, this phenomenon will cause the uneven distribution of elemental sulfur on the surface of the cathode, 42 which will cause serious passivation to increase the internal impedance of the batteries. 41 On the other hand, long-chain LiPSs will diffuse to the lithium anode and react with them to form short-chain LiPSs covering the surface of the lithium sheet, thereby hindering the diffusion of lithium ions. 35,43 Of course, a lithium anode also has many problems that need to be solved.…”