Fabrication of Assembled FeS₂ Nanosheet and Application for High-Performance Supercapacitor Electrodes

Abstract

To overcome the low-energy-density limitation of supercapacitors, we aimed to achieve a material with a high specific capacitance by manipulating the nanostructure of FeS2, which comprises the most abundant and affordable elements. In this study, nanosheet-assembled FeS2 (NSA-FeS2) was fabricated using a novel method. Sub-micron droplets of sulfur particles stabilized with polyvinylpyrrolidone were formed in silicone oil medium, and Fe(CO)5 was absorbed and reacted on the surface to form core-shell particles, ES/[Fe], with a sulfur core and an iron-containing outer shell. The high temperature treatment of ES/[Fe] produced NSA-FeS2, in which pyrite FeS2 nanosheets grew and were partially interconnected. In a three-electrode system, the as-prepared NSA-FeS2 and NSA-FeS2/polyaniline (PANI) composites exhibited specific capacitances of 763 and 976 Fg–1, respectively, at a current density of 0.5 Ag–1, with corresponding capacitance retentions of 93 and 96% after 3000 charge–discharge cycles. The capacitance retention of the NSA-FeS2/PANI composites was 49% when the current density was increased from 0.5 to 5 Ag–1. Notably, the obtained specific capacitances exhibited the highest values in pure FeS2 and FeS2-based composites, indicating the significant potential for the utilization of iron sulfide in pseudocapacitive electrode materials.

Two-Dimensional Synergistic Interfacial Orientation on Tin Oxide-Reinforced Cobalt Carbonate Hydroxide Heterostructures for High-Performance Energy Storage

“…The urea molecules play a crucial part in promoting a growth-directing agent that influences the crystalline nature and allows for the inclusion of interlayer CO 3 2– ions. The corresponding reaction − occurs in the CED process as an electric current flow through the electrolyte − CO false( normalN H 2 false) 2 + 3 H 2 normalO → normalC O 2 + 2 normalO H − + 2 false( normalN H 4 false) + normalC O 2 + H 2 normalO → normalC O 3 2 − + 2 H + normalC o 2 + + normalC O 3 2 − + 2 normalO H − → Co ( C normalO 3 ) false( OH false) 2 …”

“…The urea molecules play a crucial part in promoting a growth-directing agent that influences the crystalline nature and allows for the inclusion of interlayer CO 3 2– ions. The corresponding reaction − occurs in the CED process as an electric current flow through the electrolyte − …”

“…A two-dimensional transition metal hydroxides (2D-TMHs)-based aqueous supercapacitor electrodes have been employed in a diverse range of metal cations (Ni, Co, Mn, Fe, Cd, and Cu) to easily access more OH – in aqueous systems . It should be clear that the material properties of TMHs have notable attributes such as simple fabrication techniques, large surface regions, significantly ample electroactive sites, and integration with heterogeneous electrocatalyst supports. − Meanwhile, the emergence of effective morphological architecture with battery-type electrochemical profile has gained recognition for the TMHs electrode, which will enable further advances in the energy density of supercapacitors (SC). − In general, each charge/discharge process can cause transition of at least one phase toward the high/low valence substances, which tends to rise in the charge storage behavior of the battery-type material. Owing to the apparent battery-type charge storage process, these materials have high electrochemical activity with excellent kinetics almost equivalent or even superior to the capacitor-type counterparts. , Furthermore, the choice of the electrode is primarily governed by the energy storage mechanisms and centered on kinetic behaviors endorsement depending on either diffusion-controlled or intercalation-controlled charge storage performance of the electrode materials. , The cobalt hydroxides-based battery-type electrodes have drawn interest owing to their 2D layered structure, rich electroactive sites, multiple oxidation states, and high theoretical capacity. − In view of the environmental convenience, synthesis flexibility, and theoretical capacity, cobalt carbonate hydroxides have spurred interest as high-performance battery-type electrodes.…”

Development of PANI/FeS2/MnO2 Composite Electrode Materials for High‐Performance Supercapacitors

“…In addition, the researchers have attempted to combine FeS 2 with a conducting polymer to improve its electrochemical properties. Azimov et al [15] prepared nanosheet-assembled FeS 2 (NSA-FeS 2 ) and subsequently synthesized polyaniline on the surface of NSA-FeS 2 to obtain NSA-FeS 2 /PANI composites. In the threeelectrode test, the specific capacitance of NSA-FeS 2 and NSA-FeS 2 /PANI at 0.5 A/g was 763 and 976 F/g, respectively.…”

Robust MOF-on-MOF heterostructures as efficient cathode candidates for next-generation supercapacitors

“…Despite these advantages, there are some limitations in SCs, such as a low energy density, high self-discharge rate and manufacturing cost, which hinder its wide application toward meeting the global energy demand. 9,10 However, progress in research can address these limitations by manufacturing advanced materials for efficient SCs as they are expected to be essential for transitioning to a more sustainable energy future.…”