scholarly journals Europium oxide nanorod-reduced graphene oxide nanocomposites towards supercapacitors

RSC Advances ◽  
2020 ◽  
Vol 10 (30) ◽  
pp. 17543-17551 ◽  
Author(s):  
Parisa Aryanrad ◽  
Hamid Reza Naderi ◽  
Elmira Kohan ◽  
Mohammad Reza Ganjali ◽  
Masoud Baghernejad ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Europium Oxide ◽  
Fast Charge ◽  
Reduced Graphene ◽  
Charge Discharge

Fast charge/discharge cycles are necessary for supercapacitors applied in vehicles including, buses, cars and elevators.

scholarly journals Assembly of Na3V2(PO4)2F3@C nanoparticles in reduced graphene oxide enabling superior Na+ storage for symmetric sodium batteries

RSC Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 2958-2962 ◽  
Author(s):  
Ye Yao ◽  
Lu Zhang ◽  
Yu Gao ◽  
Gang Chen ◽  
Chunzhong Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Full Cell ◽  
Discharge Cycle ◽  
Reduced Graphene ◽  
Sodium Batteries ◽  
Charge Discharge

Symmetrical full cell of NVPF@C@rGO as both cathode and anode could light the LED lamp successfully after the 25th charge–discharge cycle at 1C.

scholarly journals From Thermal to Electroactive Graphene Nanofluids

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4545 ◽  
Author(s):  
Daniel Rueda-García ◽  
María del Rocío Rodríguez-Laguna ◽  
Emigdio Chávez-Angel ◽  
Deepak P. Dubal ◽  
Zahilia Cabán-Huertas ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Thermal Studies ◽  
Hybrid Nanofluid ◽  
Hybrid Cells ◽  
Organic Electrolytes ◽  
Flow Cells ◽  
Reduced Graphene ◽  
Distinct Line ◽  
Charge Discharge

Here, we describe selected work on the development and study of nanofluids based on graphene and reduced graphene oxide both in aqueous and organic electrolytes. A thorough study of thermal properties of graphene in amide organic solvents (N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone) showed a substantial increase of thermal conductivity and specific heat upon graphene integration in those solvents. In addition to these thermal studies, our group has also pioneered a distinct line of work on electroactive nanofluids for energy storage. In this case, reduced graphene oxide (rGO) nanofluids in aqueous electrolytes were studied and characterized by cyclic voltammetry and charge-discharge cycles (i.e., in new flow cells). In addition, hybrid configurations (both hybrid nanofluid materials and hybrid cells combining faradaic and capacitive activities) were studied and are summarized here.

scholarly journals Novel Synthesis of Holey Reduced Graphene Oxide/Polystyrene (HRGO/PS) Nanocomposites by Microwave Irradiation as Anodes for High-Temperature Lithium-Ion Batteries

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2248 ◽  
Author(s):  
Yazeed Aldawsari ◽  
Yasmin Mussa ◽  
Faheem Ahmed ◽  
Muhammad Arsalan ◽  
Edreese Alsharaeh
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
High Temperature ◽  
Microwave Irradiation ◽  
Reduced Graphene Oxide ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
Reduced Graphene ◽  
Discharge Capacities ◽  
Charge Discharge

To overcome the risk of exothermic lithium-ion battery overheating reactions, we fabricated a novel, high-temperature-stable anode material composed of holey reduced graphene oxide/polystyrene (HRGO/PS) nanocomposites synthesized through in situ bulk polymerization in the presence of HRGO via microwave irradiation. The HRGO/PS nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and electron microscopy analyses including field-emission scanning electron microscopy and transmission electron microscopy. All characterization studies demonstrated homogenous dispersion of HRGO in the PS matrix, which enhanced the thermal and electrical properties of the overall nanocomposites. These novel HRGO/PS nanocomposites exhibited excellent electrochemical responses, with reversible charge/discharge capacities of 92.1/92.78 mA·h/g at a current density of 500 mA/g with ~100% capacity retention and ~100% coulombic efficiency at room temperature. Furthermore, an examination of the electrochemical properties of these nanocomposites at 110 °C showed that HRGO/PS nanocomposites still displayed good charge/discharge capacities with stable cycle performances for 150 cycles.

scholarly journals Simple synthesis of nanosheets of rGO and nitrogenated rGO

2020 ◽  
Vol 11 ◽  
pp. 68-75 ◽  
Author(s):  
Pallellappa Chithaiah ◽  
Madhan Mohan Raju ◽  
Giridhar U Kulkarni ◽  
C N R Rao
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Large Scale ◽  
Cyclic Voltammograms ◽  
Hydrogen Treatment ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Reduced Graphene ◽  
High Yields ◽  
Charge Discharge

A green and facile approach has been developed for the large-scale synthesis of nanosheets of reduced graphene oxide (rGO) and nitrogenated reduced graphene oxide (N-rGO). This has been achieved by direct thermal decomposition of sucrose and glycine at 475 °C in ca. 7 minutes, respectively. The present protocols for synthesizing rGO and N-rGO are simple and environmentally friendly as we do not use any harmful reagents, metal catalysts and solvents. Along with that, this method offers an inexpensive route with high yields to prepare rGO with a high nitrogen content (20–25 atom %). To further improve the properties of the synthesized rGO sheets, hydrogen treatment has been carried out to reduce the oxygen functional groups. Cyclic voltammograms and charge–discharge experiments have been carried out to understand the supercapacitor behavior of rGO and hydrogen treated (H-rGO) samples.

scholarly journals Sustainable Desalination by 3:1 Reduced Graphene Oxide/Titanium Dioxide Nanotubes (rGO/TiONTs) Composite via Capacitive Deionization at Different Sodium Chloride Concentrations

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1319 ◽  
Author(s):  
John Paolo L. Lazarte ◽  
Liza Bautista-Patacsil ◽  
Ramon Christian P. Eusebio ◽  
Aileen H. Orbecido ◽  
Ruey-an Doong
Keyword(s):  
Titanium Dioxide ◽  
Graphene Oxide ◽  
Energy Consumption ◽  
Reduced Graphene Oxide ◽  
Contact Angles ◽  
Capacitive Deionization ◽  
Titanium Dioxide Nanotubes ◽  
Charging Time ◽  
Reduced Graphene ◽  
Charge Discharge

The capability of novel 3:1 reduced graphene oxide/titanium dioxide nanotubes (rGO/TiONTs) composite to desalinate using capacitive deionization (CDI) employing highly concentrated NaCl solutions was tested in this study. Parameters such as material wettability, electrosorption capacity, charge efficiency, energy consumption, and charge-discharge retention were tested at different NaCl initial concentrations—100 ppm, 2000 ppm, 15,000 ppm, and 30,000 ppm. The rGO/TiONTs composite showed good material wettability before and after CDI runs with its contact angles equal to 52.11° and 56.07°, respectively. Its two-hour electrosorption capacity during CDI at 30,000 ppm NaCl influent increased 1.34-fold compared to 100 ppm initial NaCl influent with energy consumption constant at 1.11 kWh per kg with NaCl removed. However, the percentage discharge (concentration-independent) at zero-voltage ranged from 4.9–7.27% only after 30 min of desorption. Repeated charge/discharge at different amperes showed that the slowest charging rate of 0.1 A·g−1 had the highest charging time retention at 60% after 100 cycles. Increased concentration likewise increases charging time retention. With this consistent performance of a CDI system utilizing rGO/TiONTs composite, even at 30,000 ppm and 100 cycles, it can be a sustainable alternative desalination technology, especially if a low charging current with reverse voltage discharge is set for a longer operation.

Encapsulation of NiCo2O4 in nitrogen-doped reduced graphene oxide for sodium ion capacitors

2018 ◽  
Vol 6 (29) ◽  
pp. 14146-14154 ◽  
Author(s):  
Dongfang Yang ◽  
Qinglan Zhao ◽  
Liqing Huang ◽  
Binghui Xu ◽  
Nanjundan Ashok Kumar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electronic Conductivity ◽  
Sodium Ion ◽  
Volume Changes ◽  
Nitrogen Doped ◽  
Reduced Graphene ◽  
Charge Discharge

The graphene framework guarantees good electronic conductivity and provides space for accommodating the volume changes of NiCo2O4 particles during charge/discharge.

scholarly journals FeNb2O6/reduced graphene oxide composites with intercalation pseudo-capacitance enabling ultrahigh energy density for lithium-ion capacitors

RSC Advances ◽  
2021 ◽  
Vol 11 (51) ◽  
pp. 32248-32257
Author(s):  
Shuying Kong ◽  
Xu Zhang ◽  
Binbin Jin ◽  
Xiaogang Guo ◽  
Guoqing Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Density ◽  
Reduced Graphene Oxide ◽  
Hybrid Material ◽  
Lithium Ion ◽  
Ultrahigh Energy ◽  
Fast Charge ◽  
Reduced Graphene ◽  
Oxide Composites

FeNb2O6/reduced graphene oxide (FNO/rGO) hybrid material as a fast charge anode for LICs that provides a solution to overcome the discrepancy in kinetics between battery-type anodes and capacitive cathodes.

Analysis of Deposition Methods for Lithium-Ion Battery Anodes Using Reduced Graphene Oxide Slurries on Copper Foil

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
James Garofalo ◽  
John Lawler ◽  
Daniel Walczyk ◽  
Nikhil Koratkar
Keyword(s):  
Graphene Oxide ◽  
Lithium Ion Battery ◽  
Reduced Graphene Oxide ◽  
Copper Foil ◽  
Lithium Ion ◽  
High Volume ◽  
Discharge Rates ◽  
Reduced Graphene ◽  
Deposition Height ◽  
Charge Discharge

Graphene oxide (GO) slurries were deposited onto copper foil for use in lithium-ion battery anodes to determine the best deposition method(s) for research or high-volume manufacturing. Four deposition methods were tested: doctor blade, Mayer rod, slot die, and low volume low pressure (LVLP) spray. Analytical models that link tooling and process characteristics to mass flow rate of slurry and the resulting dry deposition height are developed and validated experimentally. While all methods successfully produced functioning batteries, a number of different qualitative and quantitative metrics from experimental results identified the best method for both situations. Observations were recorded on adhesion, deposition consistency, usability, and cleanability. Data on specific discharge capacity were recorded to show performance over the anode lifetime and at different charge/discharge rates. The data indicate that anodes produced using reduced graphene oxide (rGO) deliver a specific charge storage capacity of 50 to 400 mAh/g at charge–discharge rates of 1 C to 0.05 C. Doctor blading proved to be best for laboratory setups because of its adjustability, while the Mayer rod shows promise for high-volume manufacturing due to better performance and the use of nonadjustable, dedicated tooling. All methods, analysis, and metrics are discussed.

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