A novel synthesis of ultra thin graphene sheets for energy storage applications using malonic acid as a reducing agent

2014 ◽  
Vol 2 (47) ◽  
pp. 20345-20357 ◽  
Author(s):  
Anil Kumar ◽  
Mahima Khandelwal

Novel ultrathin graphene sheets (0.41 ± 0.03 nm) with increased sp2 character, high specific capacitance and charge–discharge capability have been synthesized and demonstrated to have potential energy storage applications.

2018 ◽  
Vol 15 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Dipanwita Majumdar

Ruthenium oxides owing to their high specific capacitance have been widely identified as promising materials for electrochemical charge storage devices. However, high priced ruthenium precursors restrict their commercial usage. Accordingly, numerous explorations investigated the influences on capacitive behavior of ruthenium oxide on blending with varied materials like other metal oxides, activated carbons, conducting polymers, CNTs and functionalized graphene systems as composites. The aim had been to optimize the material cost without compromising with but improving the composite electrochemical performances. The scientific explorations reveal that the overall specific capacitance of composites is a strongly related to the ruthenium oxide (RuO2) present in the system since it is the main electro-active material providing the Faradaic pseudocapacitances besides the electrical double layer contributions from the base carbon component of the composite. Major progress in the theoretical and practical research and development in this particular field has enviced a large number of research articles and technical reports in the recent past. The current investigations focus on utilizing minimum amount of metal in the composite; upholding the synergistic effect from the metal oxide and the support (carbon materials generally) to obtain better electrochemical signatures. Optimization of important factors leading to reduced nanostructure agglomeration, minimum electrostatic resistance and ultrafast proton/electrons diffusion through the hollow porous structures may ultimately result to the theoretically expected specific capacitance. Nonetheless, to the best of knowledge of the author, there is no systematic review available pertaining to recent advancement of the composites of RuO2. Thus, this overview categorically narrates recent progresses on the fabrication, performances and achievements of ruthenium oxide composite as electrode material in energy storage applications which will be beneficial especially to the newcomers in this field of research.


2017 ◽  
Vol 5 (3) ◽  
pp. 925-930 ◽  
Author(s):  
Bingjie Wang ◽  
Qingqing Wu ◽  
Hao Sun ◽  
Jing Zhang ◽  
Jing Ren ◽  
...  

A graphene/(molybdenum disulfide) hybrid fiber with an intercalated nanostructure is designed to effectively combine the high electrical conductivity from graphene sheets and high pseudocapacitance from molybdenum disulfide sheets. It has been demonstrated to fabricate a flexible fiber-shaped supercapacitor with a high specific capacitance of 368 F cm−3.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1143 ◽  
Author(s):  
Anil Yedluri ◽  
Tarugu Anitha ◽  
Hee-Je Kim

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.


2015 ◽  
Vol 44 (19) ◽  
pp. 9221-9229 ◽  
Author(s):  
K. Bhattacharya ◽  
P. Deb

Here, the novel Fe3O4-C hybrid nanocomposite demonstrates high specific capacitance (S.C.) than the pristine Fe3O4nanospheres due to the presence of the highly conducting carbon quantum dots.


RSC Advances ◽  
2020 ◽  
Vol 10 (38) ◽  
pp. 22836-22847
Author(s):  
P. Nagaraju ◽  
M. Arivanandhan ◽  
A. Alsalme ◽  
A. Alghamdi ◽  
R. Jayavel

Nanoparticles of α-molybdenum oxide (α-MoO3) are directly grown on graphene sheets using a surfactant-free facile one step ultrafast in situ microwave irradiation method.


RSC Advances ◽  
2015 ◽  
Vol 5 (64) ◽  
pp. 51773-51778 ◽  
Author(s):  
Jinfeng Sun ◽  
Jinqing Wang ◽  
Zhangpeng Li ◽  
Zhigang Yang ◽  
Shengrong Yang

3D hierarchical bismuth (Bi)-based compounds with controllable sizes and morphologies exhibit high specific capacitance and superior rate capability.


2020 ◽  
Vol 4 (3) ◽  
pp. 1320-1331 ◽  
Author(s):  
Rohit G. Jadhav ◽  
Devraj Singh ◽  
Shaikh M. Mobin ◽  
Apurba K. Das

A binder-free electrodeposited organic–inorganic multifunctional nanohybrid electrode exhibits high specific capacitance with electrocatalytic water splitting performance.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2718
Author(s):  
Shujahadeen B. Aziz ◽  
M. A. Brza ◽  
Iver Brevik ◽  
M. H. Hamsan ◽  
Rebar T. Abdulwahid ◽  
...  

In this work, plasticized polymer electrolyte films consisting of chitosan, ammonium nitrate (NH4NO3) and glycerol for utilization in energy storage devices was presented. Various microscopic, spectroscopic and electrochemical techniques were used to characterize the concerned electrolyte and the electrical double-layer capacitor (EDLC) assembly. The nature of complexation between the polymer electrolyte components was examined via X-ray diffraction analysis. In the morphological study, field emission scanning electron microscopy (FESEM) was used to investigate the impact of glycerol as a plasticizer on the morphology of films. The polymer electrolyte (conducting membrane) was found to have a conductivity of 3.21 × 10−3 S/cm. It is indicated that the number density (n), mobility (μ) and diffusion coefficient (D) of ions are increased with the glycerol amount. The mechanism of charge storing was clarified, which implies a non-Faradaic process. The voltage window of the polymer electrolyte is 2.32 V. It was proved that the ion is responsible for charge-carrying via measuring the transference number (TNM). It was also determined that the internal resistance of the EDLC assembly lay between 39 and 50 Ω. The parameters associated with the EDLC assembly are of great importance and the specific capacitance (Cspe) was determined to be almost constant over 1 to 1000 cycles with an average of 124 F/g. Other decisive parameters were found: energy density (18 Wh/kg) and power density (2700 W/kg).


Nanoscale ◽  
2015 ◽  
Vol 7 (46) ◽  
pp. 19705-19713 ◽  
Author(s):  
Suman Kumari Jhajharia ◽  
Kaliaperumal Selvaraj

A rapid, inexpensive and safely scalable nanoperforation process for graphene sheets at ambient conditions is reported herein. The holey graphene exhibits retainable high specific capacitance due to perforation. DFT calculations provide direct clues about the nanoscopic perforation.


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