scholarly journals Investigation on the Mass Distribution and Chemical Compositions of Various Ionic Liquids-Extracted Coal Fragments and Their Effects on the Electrochemical Performance of Coal-Derived Carbon Nanofibers (CCNFs)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 664
Author(s):  
Shuai Tan ◽  
Theodore John Kraus ◽  
Mitchell Ross Helling ◽  
Rudolph Kurtzer Mignon ◽  
Franco Basile ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Electrochemical Performance ◽  
Carbon Nanofibers ◽  
Mass Distribution ◽  
Electrode Materials ◽  
Gas Chromatography Mass Spectrometry ◽  
Electrochemical Performances ◽  
Diffusion Resistance ◽  
Chemical Compositions ◽  
Holistic Understanding

Coal-derived carbon nanofibers (CCNFs) have been recently found to be a promising and low-cost electrode material for high-performance supercapacitors. However, the knowledge gap still exists between holistic understanding of coal precursors derived from different solvents and resulting CCNFs’ properties, prohibiting further optimization of their electrochemical performance. In this paper, assisted by laser desorption/ionization (LDI) and gas chromatography–mass spectrometry (GC–MS) technologies, a systematic study was performed to holistically characterize mass distribution and chemical composition of coal precursors derived from various ionic liquids (ILs) as extractants. Sequentially, X-ray photoelectron spectroscopy (XPS) revealed that the differences in chemical properties of various coal products significantly affected the surface oxygen concentrations and certain species distributions on the CCNFs, which, in turn, determined the electrochemical performances of CCNFs as electrode materials. We report that the CCNF that was produced by an oxygen-rich coal fragment from C6mimCl ionic liquid extraction showed the highest concentrations of quinone and ester groups on the surface. Consequentially, C6mimCl-CCNF achieved the highest specific capacitance and lowest ion diffusion resistance. Finally, a symmetric carbon/carbon supercapacitor fabricated with such CCNF as electrode delivered an energy density of 21.1 Wh/kg at the power density of 0.6 kW/kg, which is comparable to commercial active carbon supercapacitors.

scholarly journals Advances in sodium secondary batteries utilizing ionic liquid electrolytes

2019 ◽  
Vol 12 (11) ◽  
pp. 3247-3287 ◽  
Author(s):  
Kazuhiko Matsumoto ◽  
Jinkwang Hwang ◽  
Shubham Kaushik ◽  
Chih-Yao Chen ◽  
Rika Hagiwara
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Electrochemical Performance ◽  
Electrode Materials ◽  
Liquid Electrolytes

This review summarizes the use of ionic liquids in Na secondary batteries and discusses their electrochemical performance with various electrode materials.

scholarly journals Waxberry-Like Nanosphere Li4Mn5O12 as High Performance Electrode Materials for Supercapacitors

2018 ◽  
Vol 8 (3) ◽  
pp. 32
Author(s):  
Peiyuan Ji ◽  
Yi Xi ◽  
Chengshuang Zhang ◽  
Chuanshen Wang ◽  
Chenguo Hu ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
High Performance ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Diffusion Path ◽  
Electrochemical Performances ◽  
Wet Chemistry ◽  
First Time ◽  
Charge Discharge

Porous materials have superior electrochemical performance owing to its their structure, which could increase the specific and contact area with the electrode. The spinel Li4Mn5O12 has a three-dimensional tunnel structure for a better diffusion path, which has the advantage of lithium ion insertion and extraction in the framework. However, multi-space spherical materials with single morphologies are rarely studied. In this work, waxberry-like and raspberry-like nanospheres for Li4Mn5O12 have been fabricated by the wet chemistry and solid-state methods for the first time. The diameter of a single waxberry- and raspberry-like nanosphere is about 1 μm and 600 nm, respectively. The specific capacitance of Li4Mn5O12 was 535 mF cm−2 and 147.25 F g−1 at the scan rate of 2 mV s−1, and the energy density was 110.7 Wh kg−1, remaining at 70% after 5000th charge-discharge cycles. Compared with raspberry-like nanosphere Li4Mn5O12, the waxberry-like nanoporous spinel Li4Mn5O12 shows the better electrochemical performance and stability; furthermore, these electrochemical performances have been improved greatly compared to the previous studies. All these results indicate that the waxberry-like nanoporous spinel Li4Mn5O12 could provide a potential application in high performance supercapacitors.

scholarly journals Revisit Electrolyte Chemistry of Hard Carbon in Ether for Na Storage

2021 ◽  
Author(s):  
Jun Pan ◽  
Yi-Yang Sun ◽  
Yehao Yan ◽  
Lei Feng ◽  
Yifan Zhang ◽  
...  
Keyword(s):  
Rational Design ◽  
Electrode Materials ◽  
Solid Electrolyte Interphase ◽  
Underlying Mechanism ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Ex Situ ◽  
Gas Chromatography Mass Spectrometry ◽  
Electrochemical Performances ◽  
Practical Applications ◽  
Sei Film

Abstract Hard carbons (HC) as an anode material in sodium ion batteries, present enhanced electrochemical performances in ether-based electrolytes, making them promising potential in practical applications. However, the underlying mechanism behind the excellent performances is still in question. Here, ex-situ nuclear magnetic resonance, gas chromatography-mass spectrometry and high-resolution transmission electron microscope were used to clarify the insightful chemistry of ether- and ester-based electrolytes in terms of solid-electrolyte-interphase (SEI) on hard carbons. The results confirm the marked electrolyte decomposition and the formation of a SEI film in EC/DEC, but no SEI film in the case of diglyme. In-situ electrochemical quartz crystal microbalance and molecule dynamics support that ether molecules have been co-intercalated into hard carbons likely. To our knowledge, these results are reported for the first time. It might be very useful for us to rational design advanced electrode materials based HC in future.

Electrochemical Performance of Graphene Nanosheets as Electrode Material for Supercapacitors

2013 ◽  
Vol 873 ◽  
pp. 581-586
Author(s):  
Liang Yu Li ◽  
Dong Lin Zhao ◽  
Dong Dong Zhang
Keyword(s):  
Electrochemical Performance ◽  
Electrode Materials ◽  
Graphene Nanosheets ◽  
Rate Capability ◽  
Nitrogen Adsorption ◽  
Rapid Expansion ◽  
Electrochemical Performances ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Coating Method

Graphene nanosheets (GNSs) were prepared from flake natural graphite by oxidation, rapid expansion and ultrasonic treatment. The morphology, structure and electrochemical performance of GNSs as electrode materials for supercapacitors were systematically investigated via high-resolution transmission electron microscopy, X-ray diffraction, nitrogen adsorption and desorption isotherms and a variety of electrochemical testing techniques. The electrodes with freestanding GNSs prepared by coating method exhibited good rate capability and reversibility at high scan rates in electrochemical performances. GNS electrode with specific surface area of 243 m2 g1 maintained a stable specific capacitance of 200 F g1 under specific current of 0.1 A g1 for 500 cycles of charge/discharge.

Electrospun carbon nanofibers surface-grown with carbon nanotubes and polyaniline for use as high-performance electrode materials of supercapacitors

RSC Advances ◽  
2014 ◽  
Vol 4 (45) ◽  
pp. 23622-23629 ◽  
Author(s):  
Zhengping Zhou ◽  
Xiang-Fa Wu ◽  
Haoqing Hou
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Performance ◽  
Carbon Nanofibers ◽  
Electrode Material ◽  
High Performance ◽  
Electrode Materials

This paper reports the synthesis and electrochemical performance of carbon nanofibers (CNFs) surface-grown with carbon nanotubes (CNTs) and nanostructured polyaniline (PANI) films, i.e., PANI/CNT/CNF, for use as a high-performance electrode material of pseudosupercapacitors.

Separator modified by Ketjen black for enhanced electrochemical performance of lithium–sulfur batteries

RSC Advances ◽  
2016 ◽  
Vol 6 (17) ◽  
pp. 13680-13685 ◽  
Author(s):  
Di Zhao ◽  
Xinye Qian ◽  
Lina Jin ◽  
Xiaolong Yang ◽  
Shanwen Wang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Cathode Side ◽  
Electrochemical Performances ◽  
Lithium Sulfur Batteries ◽  
Enhanced Electrochemical Performance ◽  
Lithium Sulfur

A routine separator modified by a Ketjen black (KB) layer on the cathode side has been investigated to improve the electrochemical performances of Li–S batteries.

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