High-performance reduced graphene oxide – red phosphorous composites anodes for lithium batteries and soft X-ray near-edge structure studies

2017 ◽  
Vol 95 (11) ◽  
pp. 1178-1182
Author(s):  
Dongniu Wang ◽  
Lucia Zuin ◽  
David Muir
Keyword(s):  
Electronic Structure ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Solid Electrolyte Interphase ◽  
Three Dimensional ◽  
Lithium Storage ◽  
Edge Structure ◽  
X Ray ◽  
Reduced Graphene

A solution method was developed to synthesize reduced graphene oxide (RGO) – red phosphorous (RP) composites. The uniform distribution of RP particles into three-dimensional conductive RGO network was obtained. Due to both improved electronic structure and mechanical properties, the hybrids delivered a high lithium storage capacity with superior rate performance. For the first time, the electronic structure, as revealed by phosphorous (P) L-edge and lithium (Li) K-edge X-ray absorption near-edge structure (XANES), provides spectroscopic evidence to identify the lithiated products and solid electrolyte interphase. Charge distribution in between RP and RGO was also found by XANES, facilitating the anchoring of active RP into RGO surface.

Simplified Synthesis of 3D Flexible Reduced Graphene Oxide-Wrapped NiCo2O4 Nanowires for High-Performance Supercapacitor

2018 ◽  
Vol 10 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Chao Pan ◽  
Hongyu Sun ◽  
Jingyi Gao ◽  
Yucai Hu ◽  
Jing Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Current Density ◽  
Three Dimensional ◽  
Simple Method ◽  
X Ray ◽  
Reduced Graphene

We introduced a simple method to construct novel three-dimensional (3D) flexible hierarchical nanocomposites by combining (1D) NiCo2O4 nanowires with 2D reduced graphene oxide (rGO) sheets. The hierarchical nanocomposite structure of rGO-wrapped NiCo2O4 (rGO-NiCo2O4) was confirmed by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The results indicated that NiCo2O4 nanowires were successfully wrapped in rGO and the morphology of the rGO-NiCo2O4 showed a three-dimensional porous structure with NiCo2O4 being homogeneously distributed in the rGO. Given their apparent advantages, these two different nanostructures were evaluated as electrodes for high-performance supercapacitors. These electrodes exhibited a high capacitance of 1824.8 F·g–1 at a current density of 0.5 A·g–1, and an excellent cycling performance extending to 5000 cycles at a high current density of 4 A·g–1. Our results clearly demonstrate that rGO sheets on NiCo2O4 nanowires can substantially improve the capacitive performance of materials and ultimately increase the cycling stability of supercapacitors. The hierarchical binary nanocomposites show excellent electrochemical properties for energy storage applications, evidencing their potential application as supercapacitors.

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