Constructing a “Pizza‐Like” MoS₂/Polypyrrole/Polyaniline Ternary Architecture with High Energy Density and Superior Cycling Stability for Supercapacitors

Abstract

the charge separation at the electrode/ electrolyte interface, and (b) the reversible faradaic reaction where the pseudocapacitance arises from reversible faradic reaction occurring at the electrode/electrolyte interface. [6][7][8] Among various electrode materials, conducting polymers such as polypyrrole (PPy) and polyaniline (PANI), [9][10][11] are receiving specifi c attentions due to their intrinsic characteristics including low cost, easy preparation, remarkable storage capacity, good conductivity, and broad voltage window. [12][13][14][15] Basically, the utilization of conducting polymers as electrode materials usually shows a considerable enhancement in specifi c energy density, but those electrodes may exhibits a poor cycling stability due to serious volumetric swelling and shrinking of conducting polymers during cycles. [16][17][18][19] An emerging solution to overcome the challenges facing conducting polymers including poor electroactive stability and weak mechanical properties is to grow conducting polymers on the surfaces of various supporting materials such as graphene, metal oxides, metal dichalcogenide, etc. [20][21][22][23][24][25] The superiority of using those supporting materials is evident because they can offer a uniform and large-surface-area substrate to immobilize conducting polymers for effi cient energy storage. [ 26,27 ] Molybdenum disulfi de (MoS 2 ) is a typical 2D layered transition metal dichalcogenide which possesses unique structure features with large interlayer distance of 1.24 Å, high electrochemical activity, and good chemical stability. Therefore, MoS 2 has become a particularly promising candidate for applications in supercapacitors [28][29][30] and lithium ion batteries. [31][32][33] Meanwhile, the weak van der Waals interaction and relative large interlayer distance between MoS 2 layers facilitates the intercalation of positive ions (H + , K + , and Li + ), resulting in enlarged effective surface area which could be used as a 2D template for growing conducting polymers or other functional nanoparticles. [34][35][36][37][38][39][40] Herein, we developed a simple and effi cient strategy to construct MoS 2 /PPy/PANI ternary hybrids via two successive polymerizations of PPy and PANI on few-layer MoS 2 (f-MoS 2 ) templates. Surprisingly, a rational design of such ternary nanocomposites enables greatly improved specifi c capacitance as Polypyrrole (PPy) and polyaniline (PANI) are most promising candidates for high energy and power density supercapacitors. However, their relative low surface area and poor cyclic stability greatly limit their practical applications. Morphology-and size-controlled micro/nanostructure formation of such materials may lead to enhanced performance. Here, the solvent-exchange method is proposed for the preparation of high-concentration few-layer MoS 2 (f-MoS 2 ) suspension in an ethanol-water mixed solvent. PPy layers with high surface coverage are formed on the resultant dispersible f-MoS 2 by in situ polymerization of pyrrole. The MoS 2 /PPy hybrid is...

Solvent exfoliation stabilizes TiS2 nanosheets against oxidation, facilitating lithium storage applications

“…Two-dimensional (2D) materials have generated much interest in recent years partly due to their potential for use in a range of applications, including supercapacitors [1][2][3] and battery electrodes. [4][5][6][7][8][9] Although graphene 10,11 is undoubtedly the most well-known and widely used 2D material, many others exist, with transition metal dichalcogenides (TMDs) being probably the most known family of inorganic 2D materials.…”

Conducting polymers: a comprehensive review on recent advances in synthesis, properties and applications

“…Performance is maintained at 83% aer 3000 charge-discharge cycles with high cycle retention. 153 A summary of studies on the use of conjugated polymers in supercapacitor applications is given in Table 1.…”

An ultrahigh‐energy density and wide potential window aqueous electrolyte supercapacitor built by polypyrrole/aniline 2‐sulfonic acid modified carbon felt electrode

“…They obtained a specific capacitance value of 1273 F g −1 at 0.5 A g −1 . In addition, high cyclic performance was obtained that maintains 83% after 3000 charge/discharge cycles 33 . In our work, aniline‐2‐sulfonic acid was used as a dopant material during the hydrothermal synthesis of PPy for the first time in the literature.…”

“…Furthermore, the energy density (E) and the power density (P) can be calculated using the following Equations () and (), respectively 6,15‐42 : …”