6 research outputs found
Co<sub>3</sub>O<sub>4</sub> Nanowires on Flexible Carbon Fabric as a Binder-Free Electrode for All Solid-State Symmetric Supercapacitor
Developing portable, lightweight,
and flexible energy storage systems
has become a necessity with the advent of wearable electronic devices
in our modern society. This work focuses on the fabrication of Co<sub>3</sub>O<sub>4</sub> nanowires on a flexible carbon fabric (CoNW/CF)
substrate by a simple cost-effective hydrothermal route. The merits
of the high surface area of the prepared Co<sub>3</sub>O<sub>4</sub> nanostructures result in an exceptionally high specific capacitance
of 3290 F/g at a scan rate of 5 mV/s, which is close to their theoretical
specific capacitance. Furthermore, a solid-state symmetric supercapacitor
(SSC) based on CoNW/CF (CoNW/CF//CoNW/CF) was fabricated successfully.
The device attains high energy and power densities of 6.7 Wh/kg and
5000 W/kg. It also demonstrates excellent rate capability and retains
95.3% of its initial capacitance after 5000 cycles. Further, the SSC
holds its excellent performance at severe bending conditions. When
a series assembly of four such devices is charged, it can store sufficient
energy to power a series combination of five light-emitting diodes.
Thus, this SSC device based on a three-dimensional coaxial architecture
opens up new strategies for the design of next-generation flexible
supercapacitors
Novel Quaternary Chalcogenide/Reduced Graphene Oxide-Based Asymmetric Supercapacitor with High Energy Density
In this work we have
synthesized quaternary chalcogenide Cu<sub>2</sub>NiSnS<sub>4</sub> (QC) nanoparticles grown in situ on 2D reduced
graphene oxide (rGO) for application as anode material of solid-state
asymmetric supercapacitors (ASCs). Thorough characterization of the
synthesized composite validates the proper phase, stoichiometry, and
morphology. Detailed electrochemical study of the electrode materials
and ASCs has been performed. The as-fabricated device delivers an
exceptionally high areal capacitance (655.1 mF cm<sup>–2</sup>), which is much superior to that of commercial micro-supercapacitors.
Furthermore, a remarkable volumetric capacitance of 16.38 F cm<sup>–3</sup> is obtained at a current density of 5 mA cm<sup>–2</sup> combined with a very high energy density of 5.68 mW h cm<sup>–3</sup>, which is comparable to that of commercially available lithium thin
film batteries. The device retains 89.2% of the initial capacitance
after running for 2000 cycles, suggesting its long-term capability.
Consequently, the enhanced areal and volumetric capacitances combined
with decent cycle stability and impressive energy density endow the
uniquely decorated QC/rGO composite material as a promising candidate
in the arena of energy storage devices. Moreover, Cu<sub>2</sub>NiSnS<sub>4</sub> being a narrow band gap photovoltaic material, this work
offers a novel protocol for the development of self-charging supercapacitors
in the days to come