29 research outputs found
Perovskite materials as superior and powerful platforms for energy conversion and storage applications
No full textAvailable online 1 November 2020In order to meet the continuously growing demand for clean energy, a plethora of advanced materials have been exploited for energy storage applications. Among these materials, perovskites belong to a relatively new family of compounds with the structural formula of ABX3. These compounds exhibit a variety of electrical, optical, and electronic properties to adopt them for a variety of energy conversion and storage applications. The present review highlights the multifaceted nature of perovskite materials by covering a brief background, common crystallographic structures, and the importance of doping with different elements. Our discussion is extended further on the strategic energy applications of perovskites in modern devices such as fuel cells, lithium batteries, supercapacitors, LEDs, and solar cells.Priyanshu Goel, Shashank Sundriyal, Vishal Shrivastav, Sunita Mishra, Deepak P. Dubal, Ki-Hyun Kim, Akash Dee
Human Hair-Derived Porous Activated Carbon as an Efficient Matrix for Conductive Polypyrrole for Hybrid Supercapacitors
No full textThe
electric double layer capacitor (EDLC) mechanism
offered by
carbon frameworks alone cannot suffice the unprecedented demand for
energy. Hence, including a pseudocapacitive material (conducting polymer)
in the carbon framework can impart additional pseudocapacitance to
the material, thereby improving its electrochemical performance. Herein,
human hair as a biowaste resource with inherent heteroatoms has been
subjected to chemical activation at 800 °C to yield human hair-derived
activated carbon (HHAC). Subsequently, an in situ chemical oxidation
technique has been employed to generate the composite of HHAC and
polypyrrole (HHAC/PPy). The HHAC/PPy composite when tested in 1 M
H2SO4 outperforms pristine HHAC and PPy, with
a higher specific capacitance of 358 F/g compared to 274 and 53 F/g
obtained for individual materials, respectively (at 0.5 A/g). Moreover,
the HHAC/PPy composite also solved the problem of low cyclic stability
in the conducting polymers by maintaining 84.2% of the initial capacitance
after 5000 charge–discharge cycles. In addition, a HHAC/PPy//HHAC
asymmetrical supercapacitor device was assembled in an aqueous electrolyte
(1 M H2SO4), which delivered an ultrahigh energy
density of 53.3 W h/kg with a respectable power density of 408.5 W
h/kg that can help in avoiding costly and toxic organic electrolytes.
Our study achieved an electroactive carbon material with the synergy
of both EDLC and pseudocapacitance materials, which has great potential
for supercapacitor applications
Improved electrochemical performance of rGO/TiO2 nanosheet composite based electrode for supercapacitor applications
No full textEnhanced electrochemical performance of nickel intercalated ZIF-67/rGO composite electrode for solid-state supercapacitors
No full textPerformance Comparison Between InP-ON and SON MOSFET at Different Nanotechnology Nodes Using 2-D Numerical Device Simulation
No full textWS2/Carbon Composites and Nanoporous Carbon Structures Derived from Zeolitic Imidazole Framework for Asymmetrical Supercapacitors
No full textTransition
metal dichalcogenides (TMDs) are generating immense
research interest in the field of supercapacitors owing to their 2D
morphology and other existing material properties. Nonetheless, more
research efforts are needed to address their low conductivity and
relatively poor cycle stability. In the present work, an asymmetrical
supercapacitor (ASC) is assembled using a WS2/carbon composite
as a positive electrode and nanoporous carbon (NPC) (derived from
zeolitic imidazolate framework (ZIF-8)) as a negative electrode. In
the presence of 1 M H2SO4 aqueous electrolyte,
the above ASC has yielded excellent electrochemical performance due
to the efficient combination of the feature of redox active WS2 nanorods and highly conductive NPC. In individual studies,
the WS2/Z8-800 (positive) and Z8-800 (negative) electrodes
have delivered specific capacitances of 248.7 and 437.6 F/g, respectively.
The full ASC has been charged-balanced to fabricate a 1.4 V device,
which has delivered an energy density of 25 Wh/kg upon discharging
at a power rate of 801 W/kg. The study should also open up future
opportunities to explore other sulfide based TMDs in conjugation with
nanoporous carbon for the development of advanced supercapacitors
High-Performance Symmetrical Supercapacitor with a Combination of a ZIF-67/rGO Composite Electrode and a Redox Additive Electrolyte
No full textThe synthesis of
a highly porous composite of ZIF-67 and reduced
graphene oxide (rGO) using a simple stirring approach is reported.
The composite has been investigated as an electrode to be assembled
in a supercapacitor. In the presence of an optimized redox additive
electrolyte (RAE), that is, 0.2 M K3[Fe(CN)6] in 1 M Na2SO4, the ZIF-67/rGO composite electrode
has combined the properties of improved conductivity, high specific
surface area, and low resistance. The proposed composite electrode
in the three-electrode system shows an ultrahigh specific capacitance
of 1453 F g–1 at a current density of 4.5 A g–1 within a potential window of −0.1 to 0.5 V.
Further, the ZIF-67/rGO composite electrode was used to fabricate
a symmetrical supercapacitor whose operation in the presence of the
RAE has delivered high values of specific capacitance (326 F g–1 at a current density of 3 A g–1) and energy density (25.5 W h kg–1 at a power
density of 2.7 kW kg–1). The device could retain
about 88% of its initial specific capacitance after 1000 repeated
charge–discharge cycles. The practical usefulness of the device
was also verified by combining two symmetrical supercapacitors in
series and then lighting a white light-emitting diode (illumination
for 3 min). This study, for the first time, reports the application
of a ZIF-based composite (ZIF-67/rGO) in the presence of an RAE to
design an efficient supercapacitor electrode. This proposed design
is also scalable to a flexible symmetric device delivering high values
of specific capacitance and energy density
