High-performance flexible transparent micro-supercapacitors from nanocomposite electrodes encapsulated with solution processed MoS2 nanosheets

Sci Technol Adv Mater. 2021 Oct 13;22(1):875-884. doi: 10.1080/14686996.2021.1978274. eCollection 2021.

Abstract

Two-dimensional molybdenum disulfide (MoS2) nanosheets have emerged as a promising material for transparent, flexible micro-supercapacitors, but their use in electrodes is hindered by their poor electrical conductivity and cycling stability because of restacking. In this paper, we report a novel electrode architecture to exploit electrochemical activity of MoS2 nanosheets. Electrochemically exfoliated MoS2 dispersion was spin coated on mesh-like silver networks encapsulated with a flexible conducting film exhibiting a pseudocapacitive behavior. MoS2 nanosheets were electrochemically active over the whole electrode surface and the conductive layer provided a pathway to transport electrons between the MoS2 and the electrolyte. As the result, the composite electrode achieved a large areal capacitance (89.44 mF cm-2 at 6 mA cm-2) and high energy and power densities (12.42 µWh cm-2 and P = 6043 µW cm-2 at 6 mA cm-2) in a symmetric cell configuration with 3 M KOH solution while exhibiting a high optical transmittance of ~80%. Because the system was stable against mechanical bending and charge/discharge cycles, a flexible micro-supercapacitor that can power electronics at different bending states was realized.

Keywords: 103 Composites; 105 Low-Dimension (1D/2D) materials; 201 Electronics / Semiconductor / TCOs; 207 Fuel cells / Batteries / Super capacitors; 50 Energy Materials; Micro-supercapacitor; flexible transparent electrode; molybdenum disulfide; nanocomposite; pseudocapacitance.

Grants and funding

This work was supported by a Korea Basic Science Institute (KBSI) National Research Facilities & Equipment Center (NFEC) grant, funded by the Korea government (Ministry of Education) (No. 2019R1A6C1010031).