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Author

Chengyang Wang

Other affiliations: Chinese Ministry of Education
Bio: Chengyang Wang is an academic researcher from Tianjin University. The author has contributed to research in topics: Carbon & Anode. The author has an hindex of 33, co-authored 141 publications receiving 3191 citations. Previous affiliations of Chengyang Wang include Chinese Ministry of Education.


Papers
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Journal ArticleDOI
TL;DR: In this article, the effects of the PAN/RL mass ratios varying from 9/1,7/3 to 5/5 and heat-treatment temperatures (HTTs) in the range from 800, 1000 to 1300 °C on morphology and structure of carbon nanofibrous webs (CNFs) are systematically studied.

229 citations

Journal ArticleDOI
TL;DR: In this paper, a series of hard carbon nanofiber-based electrodes derived from electrospun polyacrylonitrile (PAN-CNFs) have been fabricated by stabilization in air at about 280 °C and then carbonization in N 2 at heat treatment temperatures (HTT) between 800 and 1500 °C.

156 citations

Journal ArticleDOI
TL;DR: In this article, Hierarchical porous carbon (HPC) has been synthesized using sulfonated pitch as a precursor with a simple KOH activation process and the effect of the activation agent to precursor ratio on the porosity and the specific surface area is studied by nitrogen adsorption-desorption.

142 citations

Journal ArticleDOI
Youyu Zhu1, Mingming Chen1, Qi Li1, Chao Yuan1, Chengyang Wang1 
01 Apr 2018-Carbon
TL;DR: In this paper, a pyrolysis process and a reductive strategy were used to synthesize high-performance hard carbons from waste apricot shell, which inherit the unique architecture of the apricots, delivering a large interlayer spacing and a well-connected structure, which are beneficial for Na+ intercalation and transport.

123 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of pre-lithiation degrees on the crystal structure of MCMB electrode and the electrochemical capacitance behavior of LIC are investigated by X-ray diffraction (XRD) and the charge-discharge test of three-electrode cell.

111 citations


Cited by
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Journal ArticleDOI
TL;DR: In order to further improve the power and energy densities of the capacitors, carbon-based composites combining electrical double layer capacitors (EDLC)-capacitance and pseudo-Capacitance have been explored and show not only enhanced capacitance, but as well good cyclability.
Abstract: Carbon materials have attracted intense interests as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost. Activated carbons produced by different activation processes from various precursors are the most widely used electrodes. Recently, with the rapid growth of nanotechnology, nanostructured electrode materials, such as carbon nanotubes and template-synthesized porous carbons have been developed. Their unique electrical properties and well controlled pore sizes and structures facilitate fast ion and electron transportation. In order to further improve the power and energy densities of the capacitors, carbon-based composites combining electrical double layer capacitors (EDLC)-capacitance and pseudo-capacitance have been explored. They show not only enhanced capacitance, but as well good cyclability. In this review, recent progresses on carbon-based electrode materials are summarized, including activated carbons, carbon nanotubes, and template-synthesized porous carbons, in particular mesoporous carbons. Their advantages and disadvantages as electrochemical capacitors are discussed. At the end of this review, the future trends of electrochemical capacitors with high energy and power are proposed.

2,497 citations

01 Nov 2000
TL;DR: In this paper, the authors compared the power density characteristics of ultracapacitors and batteries with respect to the same charge/discharge efficiency, and showed that the battery can achieve energy densities of 10 Wh/kg or higher with a power density of 1.2 kW/kg.
Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

2,437 citations

Journal ArticleDOI
TL;DR: By critically analysing state-of-the-art technologies, this work aims to address the benefits and issues of graphene-based materials, as well as outline the most promising results and applications so far.
Abstract: Since its first isolation in 2004, graphene has become one of the hottest topics in the field of materials science, and its highly appealing properties have led to a plethora of scientific papers. Among the many affected areas of materials science, this 'graphene fever' has influenced particularly the world of electrochemical energy-storage devices. Despite widespread enthusiasm, it is not yet clear whether graphene could really lead to progress in the field. Here we discuss the most recent applications of graphene - both as an active material and as an inactive component - from lithium-ion batteries and electrochemical capacitors to emerging technologies such as metal-air and magnesium-ion batteries. By critically analysing state-of-the-art technologies, we aim to address the benefits and issues of graphene-based materials, as well as outline the most promising results and applications so far.

2,148 citations

Journal ArticleDOI
TL;DR: In this article, the textural properties and surface chemistry of KOH-activated carbons depend on not only the synthesis parameters, but also different carbon sources employed including fossil/biomass-derived materials, synthetic organic polymers, and various nanostructured carbons (e.g. carbon nanotubes, carbon nanofibers, carbon aerogels, carbide-derived carbons, graphene, etc.).
Abstract: Because of their availability, adjustable microstructure, varieties of forms, and large specific surface area, porous carbon materials are of increasing interest for use in hydrogen storage adsorbents and electrode materials in supercapacitors and lithium–sulfur cells from the viewpoint of social sustainability and environmental friendliness. Therefore, much effort has been made to synthesize and tailor the microstructures of porous carbon materials via various activation procedures (physical and chemical activation). In particular, the chemical activation of various carbon sources using KOH as the activating reagent is very promising because of its lower activation temperature and higher yields, and well-defined micropore size distribution and ultrahigh specific surface area up to 3000 m2 g−1 of the resulting porous carbons. In this feature article, we will cover recent research progress since 2007 on the synthesis of KOH-activated carbons for hydrogen and electrical energy storage (supercapacitors and lithium–sulfur batteries). The textural properties and surface chemistry of KOH-activated carbons depend on not only the synthesis parameters, but also different carbon sources employed including fossil/biomass-derived materials, synthetic organic polymers, and various nanostructured carbons (e.g. carbon nanotubes, carbon nanofibers, carbon aerogels, carbide-derived carbons, graphene, etc.). Following the introduction to KOH activation mechanisms and processing technologies, the characteristics and performance of KOH-activated carbons as well as their relationships are summarized and discussed through the extensive analysis of the literature based on different energy storage systems.

2,046 citations

Journal ArticleDOI
TL;DR: In this article, a review highlights the recent research advances in active nanostructured anode materials for the next generation of Li-ion batteries (LIBs), and the effect of nanoscale size and morphology on the electrochemical performance is presented.

1,796 citations