Mingming Chen

Bio: Mingming Chen is an academic researcher from Tianjin University. The author has contributed to research in topic(s): Carbon & Carbonization. The author has an hindex of 30, co-authored 88 publication(s) receiving 4889 citation(s). Previous affiliations of Mingming Chen include Oita University.

Supercapacitor devices based on graphene materials

Abstract: Graphene materials (GMs) as supercapacitor electrode materials have been investigated. GMs are prepared from graphene oxide sheets, and subsequently suffer a gas-based hydrazine reduction to restore the conducting carbon network. A maximum specific capacitance of 205 F/g with a measured power density of 10 kW/kg at energy density of 28.5 Wh/kg in an aqueous electrolyte solution has been obtained. Meanwhile, the supercapacitor devices exhibit excellent long cycle life along with ∼90% specific capacitance retained after 1200 cycle tests. These remarkable results demonstrate the exciting commercial potential for high performance, environmentally friendly and low-cost electrical energy storage devices based on this new 2D graphene material.

Electrochemical Performances of Nanoparticle Fe3O4/Activated Carbon Supercapacitor Using KOH Electrolyte Solution

Abstract: In this study, activated carbon (AC)-Fe3O4 nanoparticles asymmetric supercapacitor cells have been assembled and characterized in 6 M KOH aqueous electrolyte for the first time. The nanostructure Fe3O4 was prepared by the microwave method. It only cost several minutes to prepare magnetite nanoparticles with average particle size of 35 nm. The electrochemical performances of the hybrid AC-Fe3O4 supercapacitor were tested by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge−discharge tests. The results show that the asymmetric supercapacitor has electrochemical capacitance performance within potential range 0−1.2 V. The supercapacitor delivered a specific capacitance of 37.9 F/g at a current density of 0.5 mA/cm2. The result of cyclic characteristic test showed that it also can keep 82% of initial capacity over 500 cycles.

Recent development of ceria-based (nano)composite materials for low temperature ceramic fuel cells and electrolyte-free fuel cells

Abstract: In the last ten years, the research of solid oxide fuel cells (SOFCs) or ceramic fuel cells (CFC) had focused on reducing the working temperature through the development of novel materials, especially the high ionic conductive electrolyte materials. Many progresses on single-phase electrolyte materials with the enhanced ionic conductivity have been made, but they are still far from the criteria of commercialization. The studies of ceria oxide based composite electrolytes give an alternative solution to these problems because of their impressive ionic conductivities and tunable ionic conduction behaviors. Significant advances in the understanding the ceria based composite material and construction of efficient fuel cell systems have been achieved within a short period. This report reviews recent developments of ceria-based composite from different aspects: materials, fundamentals, technologies, fabrication/construction parameters, electrochemistry and theoretical studies. Particular attention is given to ceria-carbonate (nano)composite, including its fuel cell performance, multi-ionic transport properties, advanced applications, corresponding electrode material and stability concerning. Besides, several novel fuel cell (FC) concepts like nanowire FC, all-nanocomposite FC and single-component/electrolyte-free fuel cell (SC-EFFC) are presented. This mini-review emphasizes the promise of ceria-based composites for advanced FC application and highlights the breakthrough of SC-EFFC research for high efficient energy conversion.

Hierarchical porous carbon derived from sulfonated pitch for electrical double layer capacitors

Abstract: Hierarchical porous carbon (HPC) has been synthesized using sulfonated pitch as a precursor with a simple KOH activation process. Sulfonated pitch has a high content of oxygen-containing groups which enable it to be easily wetted in KOH solution and facilitate the activation process. The effect of the activation agent to precursor ratio on the porosity and the specific surface area is studied by nitrogen adsorption–desorption. A maximum specific surface area of 3548 m 2 g −1 is achieved with a KOH to sulfonated pitch ratio of 3 and this produces a structure with micro-, meso- and macropores. Among the various HPC samples, the sample prepared with an activation agent to precursor ratio of 1.5 exhibits the best electrochemical performance as an electrode in an electrical double layer capacitor (EDLC) in 6 M KOH electrolyte. Its gravimetric specific capacitance is 157 F g −1 at a current density of 100 A g −1 and it has a capacitance retention ratio of 98.4% even after 10,000 cycles. The sample also presents outstanding electrochemical performance in 1 M Li 2 SO 4 and 1 M TEA BF 4 /PC electrolytes. Thus, HPC derived from sulfonated pitch is a promising electrode material for EDLCs.

Samarium doped ceria–(Li/Na)2CO3 composite electrolyte and its electrochemical properties in low temperature solid oxide fuel cell

Abstract: A composite of samarium doped ceria (SDC) and a binary carbonate eutectic (52 mol% Li2CO3/48 mol% Na2CO3) is investigated with respect to its morphology, conductivity and fuel cell performances. Th ...

Graphene and Graphene Oxide: Synthesis, Properties, and Applications

Abstract: There is intense interest in graphene in fields such as physics, chemistry, and materials science, among others. Interest in graphene's exceptional physical properties, chemical tunability, and potential for applications has generated thousands of publications and an accelerating pace of research, making review of such research timely. Here is an overview of the synthesis, properties, and applications of graphene and related materials (primarily, graphite oxide and its colloidal suspensions and materials made from them), from a materials science perspective.

Carbon-based Supercapacitors Produced by Activation of Graphene

Abstract: Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp 2 -bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

Laser Scribing of High-Performance and Flexible Graphene-Based Electrochemical Capacitors

Abstract: Although electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, charge and discharge faster than batteries, they are still limited by low energy densities and slow rate capabilities. We used a standard LightScribe DVD optical drive to do the direct laser reduction of graphite oxide films to graphene. The produced films are mechanically robust, show high electrical conductivity (1738 siemens per meter) and specific surface area (1520 square meters per gram), and can thus be used directly as EC electrodes without the need for binders or current collectors, as is the case for conventional ECs. Devices made with these electrodes exhibit ultrahigh energy density values in different electrolytes while maintaining the high power density and excellent cycle stability of ECs. Moreover, these ECs maintain excellent electrochemical attributes under high mechanical stress and thus hold promise for high-power, flexible electronics.

Graphene-based composites

Abstract: Graphene has attracted tremendous research interest in recent years, owing to its exceptional properties. The scaled-up and reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of possibilities to synthesize graphene-based functional materials for various applications. This critical review presents and discusses the current development of graphene-based composites. After introduction of the synthesis methods for graphene and its derivatives as well as their properties, we focus on the description of various methods to synthesize graphene-based composites, especially those with functional polymers and inorganic nanostructures. Particular emphasis is placed on strategies for the optimization of composite properties. Lastly, the advantages of graphene-based composites in applications such as the Li-ion batteries, supercapacitors, fuel cells, photovoltaic devices, photocatalysis, as well as Raman enhancement are described (279 references).

Graphene based materials: Past, present and future

Abstract: Graphene, a two dimensional monoatomic thick building block of a carbon allotrope, has emerged as an exotic material of the 21st century, and received world-wide attention due to its exceptional charge transport, thermal, optical, and mechanical properties. Graphene and its derivatives are being studied in nearly every field of science and engineering. Recent progress has shown that the graphene-based materials can have a profound impact on electronic and optoelectronic devices, chemical sensors, nanocomposites and energy storage. The aim of this review article is to provide a comprehensive scientific progress of graphene to date and evaluate its future perspective. Various synthesis processes of single layer graphene, graphene nanoribbons, chemically derived graphene, and graphene-based polymer and nano particle composites are reviewed. Their structural, thermal, optical, and electrical properties were also discussed along with their potential applications. The article concludes with a brief discussion on the impact of graphene and related materials on the environment, its toxicological effects and its future prospects in this rapidly emerging field.