Layered ternary sulfide CuSbS₂ nanoplates for flexible solid-state supercapacitors

Abstract

Layer-structured materials are advantageous for supercapacitor applications owing to their ability to host a variety of atoms or ions, large ionic conductivity and high surface area. In particular, ternary or higher-order layered materials provide a unique opportunity to develop stable supercapacitor devices with high specific capacitance values by offering additional redox sites combined with the flexibility of tuning the interlayer distance by substitution. CuSbS 2 is a ternary layered sulfide material that is composed of sustainable and less-toxic elements. We report the results of a systematic study of CuSbS 2 nanoplates of varying thickness (4.3 ± 1.4 to 105 ± 5.5 nm) for use as supercapacitors along with the effect of ionic size of electrolyte ions on the specific capacitance and long-term cycling performance behavior. We have obtained specific capacitance values as high as 120 F/g for nanoplates with thickness of 55 ± 6.5 nm using LiOH electrolyte. Electronic structure calculations based on density functional theory predict that with complete surface coverage by electrolyte ions a specific capacitance of over 1160 F/g is achievable using CuSbS 2 , making it a very attractive layer-structured material for supercapacitor applications. Additionally, the calculations indicate that lithium ions can be intercalated between the van der Waals layers without significantly distorting the CuSbS 2 structure, thereby further enhancing the specific capacitance by 85 F/g. Quasi-solid-state flexible supercapacitor devices fabricated using CuSbS 2 nanoplates exhibit an aerial capacitance value of 40 mF/cm 2 with excellent cyclic stability and no loss of specific capacitance at various bending angles. Moreover, the supercapacitors are operable over a wide temperature range. We have further compared the electrochemical behavior of CuSbS 2 with other non-layered phases in the system, namely Cu 3 SbS 3 , Cu 3 SbS 4 and Cu 12 Sb 4 S 13 that clearly highlight the importance of the layered structure for enhancing charge storage. Abstract" Supercapacitor devices using nanoplates of ternary layered sulfide CuSbS 2 exhibit very good performance with excellent cyclic stability, flexibility and can be operated over a wide temperature range.

Effect of sulfonating agent and ligand chemistry on structural and optical properties of CuSbS2particles prepared by heat-up method

“…Among these CuSbS2 is particularly interesting, but less explored material. Recent studies show that an indium-free CuSbS2 is a promising p-type material for solar cell and supercapacitor applications [10][11][12][13][14][15] . Yang et al 12 confirmed the ptype conductivity theoretically and experimentally by using density functional theory calculations and Hall effect measurements.…”

Solvent-controlled morphology of bismuth sulfide for supercapacitor applications

“…In turn, the electron propagation mechanism in Bi 2 S 3 micro-and nanospheres is expected to be more random, i.e., without a preferential direction, resulting in insufficient utilization of the electroactive sites for redox reactions at high current densities. Ramasamy et al [52] also confirmed the advantage of a nanoplate-like morphology over other morphologies for supercapacitor applications and indicated that a layered nanoplate structure ensures effective insertion and extraction of electrolyte ions.…”

Mixed Metal Sulfides for Electrochemical Energy Storage and Conversion

“…In contrast, low-temperature and energy-saving solution-based methods have been demonstrated to be very powerful to obtain desired MMSs. In this regard, many solution-based synthesis methods including coprecipitation, [29,48] hot injection, [49][50][51][52][53][54] refluxing, [55][56][57][58][59] hydro/ solvothermal, [60][61][62][63][64] electrodeposition, [65][66][67][68][69] and self-template methods [27,28,31,32] have been well established to synthesize high-quality MMSs.…”

“…However, similar to LIBs, the cycling performance of CuSbS 2 for SIBs is also very poor. [52] Copyright 2015, Royal Society of Chemistry. Panels (c-e): Reproduced with permission.…”

“…[52,53] Ramasamy et al synthesized CuSbS 2 nanoplates with varied thickness ranging from 3 to 120 nm by employing the hotinjection method. [52] The TEM images of the nanoplates with a thickness of around 19 nm are shown in Figure 13a,b. Among all the nanoplates with different thickness, the 55 ± 6.5 nm nanoplates display the highest specific capacitance in the KOH electrolyte.…”