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Template method has been used as an important method to prepare porous materials. However, there are few reports about template method employing potassium chloride as template. Here, potassium chloride is employed as a template to prepare the porous carbon, and transition metal nitrates (Fe(NO3)2,d Co(NO3)2, Ni(NO3)2) are introduced to catalyze graphitization and to result different carbon structure...
Pseudocapacitive materials with high capacitance are promising for enabling high energy density supercapacitors (SCs). Herein, 1, 4, 5, 8 tetrahydroxy anthraquinone (THAQ) with rich carbonyl groups is explored as a novel redox-active electrode material for SCs. THAQ is uniformly anchored on conductive reduced graphene oxide (rGO) sheets by π-π aromatic interactions and a robust, flexible THAQ/graphene...
Silicon-embedded porous carbon microspheres with an exceptional conductive framework for ions and electrons were obtained by electrospraying a mixed polymer solution of polystyrene and polyvinylpyrrolidone, containing silicon nanoparticles, carbon nanotubes and carbon blacks, and subsequent heat treatment. In the composite microspheres, silicon particles were embedded in the porous carbon framework...
Nitrogen-doped microporous carbon spheres (NPCSs) with a high surface area (1958 m2 g−1), large micropore volume and a high nitrogen content were synthesized by a simple one-step polymerization and subsequent ZnCl2 activation. The NPCSs can host a large number of small sulfur molecules, and restrict the reaction between the carbonate-based electrolytes and polysulfides. As a result, the NPCSs-sulfur...
This work demonstrates how a very low fraction of graphene greatly enhances the usage efficiency of carbon-based conductive additive in LiCoO2-based lithium ion batteries (LIB) and develops a strategy using binary conductive additive to have a high performance battery, especially with excellent rate performance. With a much lower fraction of carbon additive for a commercial LIB, only 0.2 wt% graphene...
The silicon/carbon (Si/C) hybrid fibers with a hierarchical core–shell structure are prepared by encapsulating Si nanoparticles in the interconnected hollow carbon fibers (Si@IHCFs) based on a dual coaxial electrospinning technique. For the hierarchical structure, Si nanoparticles are embedded in the honeycomb-like carbon framework in the fiber core, which is further wrapped by the interlocked cobweb-like...
Graphene and other carbon materials have been combined with various silicon (Si) nanostructures to accommodate the volume change of Si and enhance their electrical conductivity. However, for most of the formed hybrids, their low initial Coulombic efficiency (CE), fragile structures and poor stability cannot meet the practical application of battery. In this work, inspired by the structure and composition...
Because of high electrical conductivity, graphene has been widely investigated as conductive additive in lithium-ion batteries. Whereas, it is found that graphene has quite different influences on the rate performance in diverse evaluation systems, such as commercial soft-packed cells and coin half-cells. It has been proved that the coin cells show better high-rate performance with the increase of...
N-doped porous carbon sheets are produced by a one-step carbonization of a selected biomass precursor, eggplant. Such a carbon synergistically inherits sheet-like microstructure and naturally rich nitrogen in eggplant and shows excellent rate performance as a supercapacitor electrode due to the short ion diffusion paths.
Fe3O4 nanoparticles encapsulated in porous carbon fibers (Fe3O4@PCFs) as anode materials in lithium ion batteries are fabricated by a facile single-nozzle electrospinning technique followed by heat treatment. A mixed solution of polyacrylonitrile (PAN) and polystyrene (PS) containing Fe3O4 nanoparticles is utilized to prepare hybrid precursor fibers of Fe3O4@PS/PAN. The resulted porous Fe3O4/carbon...
Silicon (Si) has been regarded as one of the most attractive anode materials for the next generation lithium-ion batteries because of its large theoretical capacity, high safety, low cost and environmental benignity. However, the architecture of Si-based anode material still needs to be well designed to overcome the structure degradation and instability of the solid-electrolyte interphase caused by...
A porous tin peroxide/carbon (SnO2/C) composite electrode coated with an amorphous carbon layer is prepared using a facile method. In this electrode, spherical graphite particles act as supporter of electrode framework, and the interspace among particles is filled with porous amorphous carbon derived from decomposition of polyvinylidene fluoride and polyacrylonitrile. SnO2 nanoparticles are uniformly...
We report a novel monolithic porous carbon constructed by the hydrothermal self-assembly of graphene oxide sheets with poly (vinyl alcohol) as the linker in the formation process of a three-dimensional (3D) structure. All the pores in this carbon have circular cross-sections and range from micropores to mesopores to macropores and are formed by the gradual removal of trapped water. This 3D graphene...
Graphene wrapping is used to experimentally understand how a carbon coating works in improving the electrochemical performance of the LiFePO 4 cathode for a lithium ion battery. A full wrapping of LiFePO 4 by graphene is realized by a self-assembly driven by the electrostatic interaction in a graphene oxide suspension. Results indicate that a partial graphene wrapping provides a balance...
Enhancement of thermal conductivity of natural flake graphite/polymer (NFG/polymer) composite sheets, prepared with tape casting method, was studied by adding carbon-based nano-fillers including carbon black, carbon nanotube (CNT) and graphene. The in-plane thermal conductivities of the composites, i.e., the thermal conductivities along the tape casting plane, were measured. The improvement of thermal...
Natural flake graphite/polymer composite sheets were prepared using tape casting method. The in-plane thermal conductivities, i.e. the thermal conductivities along the tape casting plane, of the composites were measured and the results compared to the predictions by the Maxwell and Agari models. The comparison indicated that both models cannot predict the thermal conductivity of the natural flake...
Graphene decorated with manganese dioxide nanoparticles are prepared by electrostatic adsorption. The manganese dioxide is synthesized by a microemulsion route using the cationic surfactant hexadecyltrimethyl ammonium bromide, which dispersed in water is converted to be positively charged. The surface charge of graphene in water is negative, allowing two forms of manganese dioxide-decorated graphene...
We demonstrate a pH-mediated fine-tuning method for the transmittance and optical properties of graphene oxide membranes (GOMs) which are assembled at liquid/air interface starting from graphene oxide (GO) hydrosols. The transmittance of GOM continuously decreases with the increase of the pH value of the parent hydrosol. The size and surface chemistry of GO nanosheets are discussed to how to influence...
Porous graphitic carbons were prepared by combining chemical activation (ZnCl 2 ) with catalytic graphitization (metal Fe and Ni). The activating agent ZnCl 2 increased the surface area of porous carbon, and the catalyst (Fe, Ni) accelerated the graphitization. With increasing heat treatment temperature (600–900°C), metal Fe and Ni promoted the degree of graphitization which was characterized...
Bamboo-shaped carbon nanotubes (BCNTs), which were synthesized through chemical vapor deposition by using cresol as the carbon source, were explored as Pt catalyst support in comparison with conventional carbon nanotubes (CNTs) and Vulcan XC carbon blacks. The pyrolysis of cresol produced a large amount of pentagon defects introduced in the walls of BCNTs, which could possess higher chemical activity...
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