Designing a Copper‐ and Silver‐Sulfide Composite with Co₃O₄ for High‐Performance Electrochemical Supercapacitors

Abstract

Electronic devices have driven modern lifestyle demands for efficient and environmentally friendly energy storage appliances. This paper reports the simple design of an efficient, cost‐effective pseudocapacitor electrode based on copper sulfide (Cu2S) and silver sulfide (Ag2S) composites with cobalt oxide (Co3O4) for high‐performance energy storage devices. A simple one‐pot approach was used to synthesize hexagonal sheets of Co3O4 and a successive ionic layer adsorption and reaction method was exploited to coat these sheets with nanostructures of Cu2S and Ag2S. The resulting three‐dimensional (3D) Co3O4/Cu2S and Co3O4/Ag2S composite electrode contained a high loading of Cu2S and Ag2S nanoparticles (metal sulfides) on the hexagonal sheets of Co3O4 (metal oxide), which offers a highly conductive network assisting in rapid charge‐transfer reactions and reduces the internal resistance of the electrode. A symmetrical supercapacitor based on Co3O4/Cu2S//Co3O4/Cu2S showed a high areal capacitance of 1080 mF cm−2, which was significantly higher than that of the Co3O4/Ag2S//Co3O4/Ag2S symmetric supercapacitor (645 mF cm−2). These results show that the Co3O4/Cu2S composite heterostructure is a promising electrode architecture for high performance pseudocapacitors.

Highly stable binary composite of nickel silver sulfide ( NiAg 2 S ) synthesized using the hydrothermal approach for high‐performance supercapattery applications

“…The peaks at (101), (021), (211), (131), and (401) are correlated to JCPDF-00-002-0693-NiS, which confirms the formation of nickel sulfide. Moreover, the XRD pattern of silver sulfide shows peaks at (012), (111), (À112), (À121), (121), (031), and (023), which correlates to JCPDF-089-3840-Ag 2 S. 61,62 The XRD was also used to analyze the binary compound of nickel sulfide and silver sulfide. All the peaks of the composite samples correspond to the peaks of nickel sulfide and silver sulfide, confirming the formation of nickel silver sulfide.…”

High Performance of Electrochemically Deposited NiCo2S4/CNT Composites on Nickel Foam in Flexible Asymmetric Supercapacitors

“…Many transition-metal sulfides based on multivalent ions such as Co, , Ni, , Mn, , Fe, , etc., present outstanding performance in energy storage capability and have become a class of important Faradic electrode materials for supercapacitors . Previous reports have shown that, compared with single-metal sulfide, bimetallic or polymetallic sulfides can significantly boost the conductivity of the material, which can be attributed to the synergistic effect of different metal cations. − Li et al successfully prepared Co 2+ -doped Ni 3 S 4 nanosheets by a two-step solid-state reaction under mild conditions and demonstrated that Co doping could ameliorate the cycling stability and rate capability of the electrode material. Chen et al prepared vanadium-modified NiCo 2 S 4 coated with graphene sheets, which displayed outstanding rate capability and significantly improved cycle performance.…”

Hybrid solid state supercapacitors (HSSC’s) for high energy & power density: an overview

“…[19] EDLC electrode materials are basically carboneous materials like activated carbon (AC), [20] carbon nanofibers, [21] graphene, [22][23][24] and carbon nanotubes (CNT's). [25] On the other hand, metal oxides, [26][27][28][29][30][31] and conducting polymers [32][33][34] are pseudocapacitive materials due to their redox charge storage mechanism. In the case of the hybrid system, it provides an advantage of both, by combining the energy source of the battery-like electrode with a power source of the capacitor-like electrode in a single device.…”