scispace - formally typeset
Search or ask a question
Author

Debasis Ghosh

Bio: Debasis Ghosh is an academic researcher from Jain University. The author has contributed to research in topics: Graphene & Supercapacitor. The author has an hindex of 25, co-authored 101 publications receiving 2494 citations. Previous affiliations of Debasis Ghosh include Government of India & KAIST.


Papers
More filters
Journal ArticleDOI
TL;DR: The high utility of the pseudocapacitive NiMoO4 · nH2O was achieved in its graphene based composite, which exhibited a high specific capacitance at 5 A g(-1) current density and a high energy density accompanied with long term cyclic stability.
Abstract: One-dimensional NiMoO4·nH2O nanorods and their graphene based hybrid composite with good electrochemical properties have been synthesized by a cost effective hydrothermal procedure. The formation of the mixed metal oxide and the composite was confirmed by XRD, XPS and Raman analyses. The morphological characterizations were carried out using FESEM and TEM analyses. The materials were subjected to electrochemical characterization through cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) studies with 6 M KOH as the supporting electrolyte. For NiMoO4·nH2O, a maximum specific capacitance of 161 F g−1 was obtained at 5 A g−1 current density, accompanied with an energy density of 4.53 W h kg−1 at a steady power delivery rate of 1125 W kg−1. The high utility of the pseudocapacitive NiMoO4·nH2O was achieved in its graphene based composite, which exhibited a high specific capacitance of 367 F g−1 at 5 A g−1 current density and a high energy density of 10.32 W h kg−1 at a power density of 1125 W kg−1 accompanied with long term cyclic stability.

226 citations

Journal ArticleDOI
TL;DR: An advanced aqueous asymmetric (AAS) supercapacitor has been fabricated by exploiting the as-prepared Ni@rGO-Co3S4 as a positive electrode and Ni@ rGO-Ni3S2 as a negative electrode, and promising energy densities and cycle stability indicate that it could be a potential candidate in the field ofsupercapacitors.
Abstract: Ni foam@reduced graphene oxide (rGO) hydrogel–Ni3S2 and Ni foam@rGO hydrogel–Co3S4 composites have been successfully synthesized with the aid of a two-step hydrothermal protocol, where the rGO hydrogel is sandwiched between the metal sulfide and Ni foam substrate. Sonochemical deposition of exfoliated rGO on Ni foam with subsequent hydrothermal treatment results in the formation of a rGO-hydrogel-coated Ni foam. Then second-time hydrothermal treatment of the dried Ni@rGO substrate with corresponding metal nitrate and sodium sulfide results in individual uniform growth of porous Ni3S2 nanorods and a Co3S4 self-assembled nanosheet on a Ni@rGO substrate. Both Ni@rGO–Ni3S2 and Ni@rGO–Co3S4 have been electrochemically characterized in a 6 M KOH electrolyte, exhibiting high specific capacitance values of 987.8 and 1369 F/g, respectively, at 1.5 A/g accompanied by the respective outstanding cycle stability of 97.9% and 96.6% at 12 A/g over 3000 charge–discharge cycles. An advanced aqueous asymmetric (AAS) superc...

210 citations

Journal ArticleDOI
TL;DR: It was observed that the removal of fluoride was better for bipolar connection than for monopolar connection, which might be useful in order to treat the fluoride contaminated water for drinking.

203 citations

Journal ArticleDOI
TL;DR: The EC process for removing Fe(II) from tap water is expected to be adaptable for household use and at the optimum total cost was 6.05 US$/m3.

197 citations

Journal ArticleDOI
TL;DR: In this paper, an in-situ hydrothermal method is employed to synthesize graphene/zirconium oxide composite from respective precursors graphene oxide and ZIRconium oxy-nitrate, which leads to high surface area (207.1 m2 g−1), high electrical conductivity (70.8 S cm−1, high specific capacitance (1359.99 Fg−1 at 1 mV s−1) and high electrochemical performances as supercapacitor electrode materials.
Abstract: In-situ hydrothermal method is employed to synthesize graphene/zirconium oxide composite from respective precursors graphene oxide and zirconium oxy-nitrate. In this method, the graphene oxide is reduced itself to graphene and simultaneously metal oxide gets anchor on the graphene sheets. A novel method is also developed for the preparation of vertically aligned tunable polyaniline on the graphene/zirconium oxide nanocomposite, which leads to achieve high surface area (207.1 m2 g−1), high electrical conductivity (70.8 S cm−1), high specific capacitance (1359.99 Fg−1 at 1 mV s−1), and high electrochemical performances as supercapacitor electrode materials. This vertically aligned conducting polymer gets easy contact with electrolyte ions and provides numerous redox active sites during charging and discharging. Moreover, such a simple and low cost assembly approach can be a pioneer for the large-scale production of various functional architectures for energy storage and conversions.

152 citations


Cited by
More filters
01 Nov 2000
TL;DR: In this paper, the authors compared the power density characteristics of ultracapacitors and batteries with respect to the same charge/discharge efficiency, and showed that the battery can achieve energy densities of 10 Wh/kg or higher with a power density of 1.2 kW/kg.
Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

2,437 citations

01 Jan 2016

1,907 citations

Journal ArticleDOI
TL;DR: The state-of-the-art advancements in FSSCs are reviewed to provide new insights on mechanisms, emerging electrode materials, flexible gel electrolytes and novel cell designs.
Abstract: Flexible solid-state supercapacitors (FSSCs) are frontrunners in energy storage device technology and have attracted extensive attention owing to recent significant breakthroughs in modern wearable electronics In this study, we review the state-of-the-art advancements in FSSCs to provide new insights on mechanisms, emerging electrode materials, flexible gel electrolytes and novel cell designs The review begins with a brief introduction on the fundamental understanding of charge storage mechanisms based on the structural properties of electrode materials The next sections briefly summarise the latest progress in flexible electrodes (ie, freestanding and substrate-supported, including textile, paper, metal foil/wire and polymer-based substrates) and flexible gel electrolytes (ie, aqueous, organic, ionic liquids and redox-active gels) Subsequently, a comprehensive summary of FSSC cell designs introduces some emerging electrode materials, including MXenes, metal nitrides, metal–organic frameworks (MOFs), polyoxometalates (POMs) and black phosphorus Some potential practical applications, such as the development of piezoelectric, photo-, shape-memory, self-healing, electrochromic and integrated sensor-supercapacitors are also discussed The final section highlights current challenges and future perspectives on research in this thriving field

1,210 citations

Journal ArticleDOI
TL;DR: Asymmetric supercapacitors assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density, with the main focus on an extensive survey of the materials developed for ASC electrodes.
Abstract: The world is recently witnessing an explosive development of novel electronic and optoelectronic devices that demand more-reliable power sources that combine higher energy density and longer-term durability. Supercapacitors have become one of the most promising energy-storage systems, as they present multifold advantages of high power density, fast charging-discharging, and long cyclic stability. However, the intrinsically low energy density inherent to traditional supercapacitors severely limits their widespread applications, triggering researchers to explore new types of supercapacitors with improved performance. Asymmetric supercapacitors (ASCs) assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density. Recent progress made in the field of ASCs is critically reviewed, with the main focus on an extensive survey of the materials developed for ASC electrodes, as well as covering the progress made in the fabrication of ASC devices over the last few decades. Current challenges and a future outlook of the field of ASCs are also discussed.

901 citations

Journal ArticleDOI
TL;DR: In this article, a review article gives an overview of recent advances in the development of hybrid supercapacitors, storage mechanism, criteria of formation, components, different electrode and electrolyte materials, electrochemical profile assessment, design fabrication and their applications.
Abstract: Hybrid supercapacitors with their improved performance in energy density without altering their power density have been in trend since recent years. The hybrid supercapacitor delivers higher specific capacitance in comparison to the existing electric double layer capacitor (EDLC) and pseudocapacitors. Generally, the asymmetric behavior of hybrid supercapacitors which is the combination of EDLC and pseudocapacitor acts as an enhancer in its respective capacitance values. This asymmetric approach marks a new beginning towards the much-needed pollution free, long lasting and proficient energy-storing performance. Corresponding to their utilization in hybrid electric vehicles and similar sort of power necessity based devices; the research in developing new advanced storage devices finds an enormous and vast future ahead. The most significant factor for the energy efficient applications demands a considerably higher ratio of surface to the volume by incorporation of new materials. This review article gives an overview of recent advances in the development of hybrid supercapacitors, storage mechanism, criteria of formation, components, different electrode and electrolyte materials, electrochemical profile assessment, design fabrication and their applications.

862 citations