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 ◽  
...  

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.

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 ◽  
...  

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.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2248 ◽  
Author(s):  
Yazeed Aldawsari ◽  
Yasmin Mussa ◽  
Faheem Ahmed ◽  
Muhammad Arsalan ◽  
Edreese Alsharaeh

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.


2020 ◽  
Vol 11 ◽  
pp. 68-75 ◽  
Author(s):  
Pallellappa Chithaiah ◽  
Madhan Mohan Raju ◽  
Giridhar U Kulkarni ◽  
C N R Rao

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.


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

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.


RSC Advances ◽  
2020 ◽  
Vol 10 (30) ◽  
pp. 17543-17551 ◽  
Author(s):  
Parisa Aryanrad ◽  
Hamid Reza Naderi ◽  
Elmira Kohan ◽  
Mohammad Reza Ganjali ◽  
Masoud Baghernejad ◽  
...  

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


2018 ◽  
Vol 6 (29) ◽  
pp. 14146-14154 ◽  
Author(s):  
Dongfang Yang ◽  
Qinglan Zhao ◽  
Liqing Huang ◽  
Binghui Xu ◽  
Nanjundan Ashok Kumar ◽  
...  

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


2018 ◽  
Vol 140 (9) ◽  
Author(s):  
James Garofalo ◽  
John Lawler ◽  
Daniel Walczyk ◽  
Nikhil Koratkar

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.


RSC Advances ◽  
2016 ◽  
Vol 6 (101) ◽  
pp. 98581-98587 ◽  
Author(s):  
Na Xu ◽  
Jiaqi Liang ◽  
Tao Qian ◽  
Tingzhou Yang ◽  
Chenglin Yan

2D hybrid sheets of V2O5 and reduced graphene oxide (rGO/V2O5) have been synthesized using a hydrothermal method.


2018 ◽  
Vol 6 (47) ◽  
pp. 24256-24266 ◽  
Author(s):  
Jiage Yu ◽  
Hui Huang ◽  
Yongping Gan ◽  
Yang Xia ◽  
Chu Liang ◽  
...  

Building a rational nanoarchitecture of TiO2 nanowires/RGO composite is a promising method to satisfy the demands of excellent Li+/Na+ storage performance.


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