Co₉S₈ embedded into N/S doped carbon composites: in situ derivation from a sulfonate-based metal–organic framework and its electrochemical properties

Abstract

Co9S8/NSC was synthesized via an in situ transformation from a sulfonate-based Co-MOF without additional sulfur source, delivering long-term cycling stability.

Bimetal‐organic Framework‐derived Co9S8/ZnS@NC Heterostructures for Superior Lithium‐ion Storage

“…To evaluate the superior electrochemical performance of the hetero‐structural composites, Figure a showed the cyclic voltammetry profiles of Co 9 S 8 /ZnS@NC at a scan rate of 0.2 mV s −1 between 0.01 V and 3.0 V with multiple redox peaks. In the initial scan, the broad peak around 0.50–1.30 V attributed to the conversion of Co 9 S 8 and ZnS, the alloying reaction of Zn (FigureS7a), and the formation of solid electrolyte interface (SEI) film . Afterwards, the redox peaks at around 1.30/2.0 V is corresponded to conversion reaction between Co 9 S 8 and Co/Li 2 S, and the another couple of redox peak at around 0.80/1.58 V can be ascribed to the conversion reaction between ZnS and Zn/Li 2 S, and alloying/dealloying transformation Zn and Li x Zn .…”

“…the k 1 v and k 2 v 1/2 indicate the current response from surface capacitive contribution and diffusion contribution, respectively . Just as shown in Figure c, the surface capacitive contribution of the Co 9 S 8 /ZnS@NC electrode at 1.4 mV s −1 is about 78.4%.…”

“…Nevertheless, the commercial LIBs with graphite‐based anode used could not meet the demands of higher energy and power delivery with the development of the electric and hybrid electric vehicles and large‐scale energy storage systems . Developing alternative anode materials with excellent electrochemical performance is meaningful and urgent for the next generation LIBs, transition metal sulfides have been explored widely owing to their high theoretical capacity, low cost and easy fabrication . While the intrinsic poor electronical conductivity, huge volume change of these electrodes during charging/discharging process and sluggish Li + diffusion kinetics impede their practical applications …”

“…So far, many strategies including downsizing the particle size to fabricate hierarchical nanostructures, constructing composites with conductive carbon matrix, and integration with heterogeneous hybrids to shorten electronic and ionic transport paths, alleviate the internal strain, improve the electrical conductivity, and accommodate the volume changes during cycling, have been devoted to promote the lithium storage performance of metal sulfides. Among these effective approaches, construction of heterostructures consisted of different components with bandgaps difference, is an effective way to promote the electrochemical performance, which could generate a strong built‐in electric field ( E ‐field), promote interface charge transport of ions and electrons, thus improving the reaction kinetics .…”

Metallic Co9S8 Coupled Hollow N‐Doped Carbon Sphere with Synergistic Interface Structure for Efficient Electricity Generation in Microbial Fuel Cells

“…Raman spectrum of Co 9 S 8 /NHCS was exhibited in comparison with NHCS (Figure S9). Distinct D peak and G peak centered at 1370 and 1570 cm −1 resulted from carbonaceous materials, while a sharp Raman peak below 750 cm −1 was assigned to Co 9 S 8 /NHCS . Besides, a larger ratio of I D /I G revealed a greater number of defects or disordered sites of Co 9 S 8 /NHCS than NHCS …”