scholarly journals Synthesis of Reduced Graphene Oxide-Modified LiMn0.75Fe0.25PO4 Microspheres by Salt-Assisted Spray Drying for High-Performance Lithium-Ion Batteries

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Myeong-Seong Kim ◽  
Hyun-Kyung Kim ◽  
Suk-Woo Lee ◽  
Dong-Hyun Kim ◽  
Dianbo Ruan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Properties ◽  
Reduced Graphene Oxide ◽  
Spray Drying ◽  
Electrode Materials ◽  
High Energy ◽  
Mixed Solution ◽  
Phase Purity ◽  
Reduced Graphene ◽  
Tap Density

Abstract Microsized, spherical, three-dimensional (3D) graphene-based composites as electrode materials exhibit improved tap density and electrochemical properties. In this study, we report 3D LiMn0.75Fe0.25PO4/reduced graphene oxide microspheres synthesized by one-step salt-assisted spray drying using a mixed solution containing a precursor salt and graphene oxide and a subsequent heat treatment. During this process, it was found that the type of metal salt used has significant effects on the morphology, phase purity, and electrochemical properties of the synthesized samples. Furthermore, the amount of the chelating agent used also affects the phase purity and electrochemical properties of the samples. The composite exhibited a high tap density (1.1 g cm−3) as well as a gravimetric capacity of 161 mA h g−1 and volumetric capacity of 281 mA h cm−3 at 0.05 C-rate. It also exhibited excellent rate capability, delivering a discharge capacity of 90 mA h g−1 at 60 C-rate. Furthermore, the microspheres exhibited high energy efficiency and good cyclability, showing a capacity retention rate of 93% after 1000 cycles at 10 C-rate.

scholarly journals Synthesis of Polypyrrole/Reduced Graphene Oxide Hybrids via Hydrothermal Treatment for Energy Storage Applications

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2273 ◽  
Author(s):  
Adam Moyseowicz ◽  
Krzysztof Pająk ◽  
Katarzyna Gajewska ◽  
Grażyna Gryglewicz
Keyword(s):  
Graphene Oxide ◽  
Chemical Composition ◽  
Electrochemical Properties ◽  
Reduced Graphene Oxide ◽  
Hydrothermal Treatment ◽  
Hybrid Materials ◽  
Electrode Materials ◽  
Conductive Polymer ◽  
Surface Areas ◽  
Reduced Graphene

Herein, we propose hydrothermal treatment as a facile and environmentally friendly approach for the synthesis of polypyrrole/reduced graphene oxide hybrids. A series of self-assembled hybrid materials with different component mass ratios of conductive polymer to graphene oxide was prepared. The morphology, porous structure, chemical composition and electrochemical performance of the synthesized hybrids as electrode materials for supercapacitors were investigated. Nitrogen sorption analysis at 77 K revealed significant changes in the textural development of the synthesized materials, presenting specific surface areas ranging from 25 to 199 m2 g−1. The combination of the pseudocapacitive polypyrrole and robust graphene material resulted in hybrids with excellent electrochemical properties, which achieved specific capacitances as high as 198 F g−1 at a current density of 20 A g−1 and retained up to 92% of their initial capacitance after 3000 charge–discharge cycles. We found that a suitable morphology and chemical composition are key factors that determine the electrochemical properties of polypyrrole/reduced graphene oxide hybrid materials.

Simple construction of GdBiVO4 assembled on reduced graphene oxide for selective and sensitive electrochemical detection of chloramphenicol in food samples

2021 ◽  
Author(s):  
G. Praveen Kumar ◽  
Srinithi Subburaj ◽  
Shen-Ming Chen ◽  
Chandan Hunsur Ravikumar
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Properties ◽  
Hydrothermal Method ◽  
Reduced Graphene Oxide ◽  
Electrochemical Detection ◽  
Food Samples ◽  
Simple Construction ◽  
Facile Hydrothermal Method ◽  
Phase Purity ◽  
Reduced Graphene

In the present study, the influence of phase purity and crystallinity on the electrochemical properties of well-designed GdBiVO4@rGO nanocomposite has been fabricated by the facile hydrothermal method for the detection...

Hybrid Supercapacitors Based on Self-Assembled Electrochemical Deposition of Reduced Graphene Oxide/Polypyrrole Composite Electrodes

2021 ◽  
Vol 16 (6) ◽  
pp. 949-956
Author(s):  
Jun Ma ◽  
Junaid Ali Syed ◽  
Dongyun Su
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Electrochemical Deposition ◽  
High Energy ◽  
Carbon Cloth ◽  
Discharge Process ◽  
Rate Performance ◽  
Reduced Graphene ◽  
Self Assembled

Conductive polymers (CPs) have potential application to commercial energy storage because of their high electrochemical activity and low cost. However, an obstacle in developing CP-based supercapacitors is the degradation in their capacitance during the charge-discharge process that leads to poor rate performance. This study fabricates layers of a high-performance self-assembled polypyrrole/reduced graphene oxide (PPY/RGO) composite material on a carbon cloth through electrochemical deposition. The layered graphene improved the electrochemical properties of PPY. Carbon fiber rods were coated with the PPY/RGO composite layer, the thickness of which depends on the deposition time. Adequate capacitive behaviors were achieved by using 16 layers of polypyrrole/reduced graphene oxide, with a specific capacitance of 490 F g−1 (0.6 A g−1) and good rate performance. The results here provide a novel means of preparing graphene-based nanocomposites films for a variety of functions. A symmetric device was subsequently assembled by using electrodes featuring 16 layers of the polypyrrole/reduced graphene oxide composite. It yielded a specific capacitance of 205 F g−1 and a high energy density of 16.4 Wh kg−1. It also exhibited good cycle stability, with a capacitance retention rate of 85% for 5,000 cycles.

Sign in / Sign up

Export Citation Format

Share Document