Development of SnS₂/RGO nanosheet composite for cost-effective aqueous hybrid supercapacitors

Abstract

The development of low cost supercapacitor cells with unique capacitive properties is essential for many domestic and industrial purposes. Here we report the first ever application of SnS-reduced graphene oxide (SnS/RGO) layered nanocomposite as a superior electrode material for symmetric aqueous hybrid supercapacitors. We synthesized SnS/RGO nanocomposite comprised of nanosheets of SnS and graphene oxide via a one-pot hydrothermal approach. in situ as-synthesized SnS/RGO is devised for the first time to give high specific capacitance 500 Fg, energy density 16.67 Wh kg and power density 488 W kg. The cell retains 95% charge/discharge cycle stability up to 1000 cycles. In-short, the SnS/RGO nanosheet composite presented is a novel and advanced material for application in high stability moderate value hybrid supercapacitors. All the currently available surveys in literature state the potential applicability of SnS as the anode material for reversible lithium/sodium ion batteries (LIBs/NIBs) but there is a lack of equivalent studies on electrochemical capacitors. We filled up this knowledge gap by the use of the same material in a cost-effective, highly active hybrid supercapacitor application by utilizing its pseudocapacitance property combined with the layered capacitance property of graphene sheets.

2D/2D SnS2/MoS2 layered heterojunction for enhanced supercapacitor performance

“…Figure A, exhibits the typical CV curves of the prepared SnS 2 and SnS 2 /MoS 2 composites at the scan rate of 10mvs ‐1 with the potential window from 0.1V to 0.6V. It can obviously find typical redox peaks in each CV curves from 0.1 V to 0.6 V, which indicated a typical pseudocapacitance behavior that can be ascribed to the insertion of K + ions in the interlayer of SnS 2 and MoS 2 and reversible redox reactions occurring in SnS 2 and MoS 2 , which demonstrated that the capacitance of supercapacitor mainly originate from the faradaic redox reaction. Besides that, due to the different mole ratios of MoS 2 in the prepared composites that the redox peaks of the CV are not at the same position, which effectively indicates that MoS 2 plays an important role in the electrochemical reaction process and makes a great contribution to the capacity improvement.…”

Emergent Pseudocapacitance of 2D Nanomaterials

“…The emerging properties (e.g., ultrafast charge transfer between van der Waals-coupled layers and tunable optoelectronic properties) [180] and new physical features (e.g., superlattice Dirac points [181] and Hofstadter butterfly in magnetic field [182] ) of 2D hetero-nanosheets are originates from interlayer interactions between different nanosheets. [66,67,103,104,[184][185][186][187] Park and co-workers fabricated RGO/MoS 2 hybrid films via vacuum filtration of a mixture of GO and MoS 2 and subsequent heat-treatment. [183] Some of the 2D nanomaterials are redox active, but charge transfer is too slow to achieve the pseudocapacitance at the specific rate.…”

Recent progress and future prospects of sodium-ion capacitors

“…Transition metal sulfides (MoS 2 and SnS 2 ) with layered structure and large interplanar distance have been applied in energy storage devices in recent years [67][68][69][70]. However, the poor inherent electronic conductivity causes serious polarization and low electrode utilization efficiency.…”

“…For example, the layered SnS 2 has a large interlayer spacing of 0.59 nm in favor of the insertion/extraction of Na + . In 2016, Chauhan et al [68] synthesized , respectively. Due to superior electronic conductivity and high pseudocapacitance, the transition metal nitrides are considered as promising electrodes, especially, the VN and TiN [74][75][76].…”

“…Additionally, ionic liquid electrolytes with nonflammability, low-volatility and high ignition temperature (>300°C) other than low conductivity and high viscosity can provide large potential windows and stable solid electrolyte interphase (SEI) film with the absence of dendrites when applied in electrochemical storage systems [123]. Generally, the aqueous systems including acid-based, alkali-based and neutral electrolytes are often involved in recent years [47,68,84,117,[124][125][126]. For example, the reported Na 4 Mn 9 O 18 //AC hybrid capacitor system [127] in 1 mol L −1 NaCl aqueous solution displayed stable cycling performance ( Fig.…”