Artificially Layered CoSe₂ Nanosheets by a Dual-Templating Strategy for High-Performance Lithium–Sulfur Batteries

Abstract

Owing to the attractive merits of layered transition metal dichalcogenides (LTMDs) with van der Waals interactions, it is significant to modulate electronic structures and endow them with fascinating physiochemical properties by converting a nonlayered metal dichalcogenide into an atomic layered one. Herein, a dual-templating strategy is designed to prepare artificially layered CoSe2 nanosheets on carbon fiber cloth (L-CoSe2/CFC). It is found that not only the nanosheet morphology but also the layered structure is well inherited from the precursor of layered Co(OH)2 nanosheets through a wet-solution ion-exchange approach. The as-prepared L-CoSe2/CFC serves as an efficient multifunctional interlayer to solve the challenges of “shuttling effect” and slow multistep reaction kinetics in lithium–sulfur batteries (LSBs), thus dramatically improving their electrochemical performance. Benefiting from the L-CoSe2 nanosheets with large interlayer spacing, strong chemical adsorption, and superior catalytic activity, L-CoSe2/CFC promotes the anchoring of lithium polysulfides (LiPSs) and their catalytic conversion. Consequently, the L-CoSe2/CFC cell yields a large reversible capacity of 1584 mAh g–1 at 0.2C and a high rate capability of 987 mAh g–1 at 4C. A high areal capacity of 4.38 mAh cm–2 after 100 cycles at 0.2C is achieved for the high-S-loading LSB (4.6 mg cm–2) using the L-CoSe2/CFC interlayer.

CoSe2 Nanoparticles with Multienzymic Activities for Antibacterial Applications

“…The Se 3d 5/2 and 3d 3/2 doublet at 54.20 and 55.14 eV, respectively, corresponds to Se 2 2– in CoSe 2 . The large peak at 59.03 eV can be related to a structure of selenium–oxygen bonding …”

Defect Engineering Activates Schottky Heterointerfaces of Graphene/CoSe2 Composites with Ultrathin and Lightweight Design Strategies to Boost Electromagnetic Wave Absorption

“…The XPS total spectrum in Figure 3b 3c). [37,38] The O element may be introduced by the oxygen-containing functional group in RGO. The 3d spectrum of Se can be divided into three main peaks located at 58.8, 54.8, and 53.6 eV, corresponding to Se-O-Se, Se-Se, and Co-Se, respectively (Figure 3d).…”

Three-Dimensional Carbon Networks Decorated with Co Nanocatalysts as Multifunctional Interlayers for a High-Performance Lithium–Sulfur Battery

“…Therefore, the introduction of transition metal-modified carbon materials or hetero-atom doping is an important strategy for interlayer design. For example, Xu et al . proposed a strategy for the preparation of layered CoSe 2 nanosheets on CF cloth to suppress the shuttle effect of LiPS.…”

“…Therefore, the introduction of transition metal-modified carbon materials or hetero-atom doping is an important strategy for interlayer design. For example, Xu et al 31 proposed a strategy for the preparation of layered CoSe 2 nanosheets on CF cloth to suppress the shuttle effect of LiPS. The transition metal compounds with high catalytic sites facilitate the catalytic conversion of polysulfides, resulting in improved LSBs performance.…”