Papers by Keyword: MCMB

Abstract: Mesocarbon microbeads (MCMB) were prepared from medium coal tar pitch by hot-treatment under certain conditions. The TG, SEM, EDX, Laser Particle Size Analysis and XRD methods were used to characterize the MCMB. The results have been shows that the pre-oxidation treatment before carbonization has a considerable effect on the morphology of MCMB; compared with the MCMB which have no pre-oxidation treatment, the surface of MCMB with pre-oxidation treatment became smoother and the surface defects decreased obviously. Pre-oxidation treatment have been narrowed the particle size distribution of MCMB. Briefly, the average particle size of MCMB with pre-oxidation is 19.751 μm, slightly larger than the untreated MCMB which has the average particle size of 18.442 μm.

Abstract: Most of the carbon foams’ preparation is conducted under either high temperature or high pressure which consumes much energy. Aimed at this problem, we proposed a novel preparation technology which utilized the albumen as the foaming agent under normal temperature and pressure. The carbon foams had a bulk density of between 0.38 and 0.44 g/cm³. Analysis of scanning electron micrographs indicated that the cells had spherical cavity, small transom, and ligament which connected spherical cavity and provided high mechanical properties. The compressive strengths ranged from 0.4 to 2.1MPa and the thermal conductivity stayed still when the content of the meso-carbon micro-beads (MCMB) varied between 0 and 10%. It is one of our method’s features that the content of MCMB has litter effect on the thermal conductivity of the carbon foams.

Abstract: A new tubular cathode support for Direct Ethanol Fuel Cell (DEFC) was prepared by the gelcasting process using mesocarbon microbead(MCMB) and graphite as the main raw materials. Through the tubular cathode electrical property test, the advantages and disadvantages of cathode tube performance are studied at different graphite proportion. The results showed that when the graphite is more than 30 percent, the charge transmission ability has become extremely close. When the graphite ratio is 40 and 50 percent, the electrical performance is the best. With the graphite doping ratio of 40 percent, the electrode electrochemical reaction will have been reinforced when the temperature is high. When the air flow is 100 ml/min, the electricity capacity is better.

Abstract: A new tubular cathode support for Direct Ethanol Fuel Cell (DEFC) was prepared by the gelcasting process using mesocarbon microbead(MCMB) and graphite as the main raw materials. The effects of different graphite doping ratios on tensile strength, bending strength, crushing strength, volume resistivity and shrinkage rate for the prepared tubular cathode support were studied by experimental test. The result showed that the prepared tubular cathode support had very good comprehensive performance. The tubular cathode support with 10% graphite exhibits the best performance such as bending strength 25MPa and resistivity30µΩ•m, and it satisfied the DEFC cathode working conditions and performance requirements.

Abstract: By using the mesocarbon microbead (MCMB) and graphite as raw material, the tubular cathode green bodies of a direct ethanol fuel cell（DEFC）are shaped by the gelcasting technology and the tubular cathode is prepared by spraying the diffusion layer and the Pt/C catalyst layer after the sintering process. Through the tubular cathode physical performance and electrical property test, the advantages and disadvantages of cathode tube performance are studied at different graphite proportion. The results showed that with the increase of graphite, the ratio porosity of cathode tube support body increases at first and then decreases. However, the density has a converse trend. While the maximum porosity of the cathode tube is more than 0.5 and the corresponding density is 0.95g/cm3. Strength test showed that the cathode tube strength is better with the graphite ratio from 0 to 40 percent and can meet the actual needs. Electrical property tests showed that the cathode tube has higher current density with the graphite ratio of 40 and 50 percent.

Abstract: Si-Cu alloys have been prepared by electroless depositions with different process. Si-Cu/MCMB materials have been prepared by carbonization of the mixture of Si-Cu, MCMB and mesophase pitch. The influences of electroless deposition condition and heat-treatment temperature on the anodic performance of Cu-Si/MCMB have been studied. Compared with Si/MCMB, Si-Cu/MCMB has more stable cyclical performance. Furthermore, the Si-Cu/MCMB sample produced by cleaning and then electroless deposition on Si shows the better anodic performance than the Si-Cu/MCMB sample produced by direct electroless deposition on Si, because the former sample has more Cu contents than the latter sample.

Abstract: Tubular cathode and plate anode were prepared by gel-casting process and coating process, which used mesocarbon microbead(MCMB) as raw materials, then cathode and anode were assembled to prepare single fuel cell. The generation performance for single tubular direct methanol fuel cell was tested under different electrolyte temperatures, methanol concentrations and oxygen flow rates, and the factors that affected the cell performance were discussed. The results showed that temperature and oxygen flow rate were the important factors of the generation performance in tubular direct methanol fuel cell (TDMFC), but the methanol concentration had a relatively smaller impact on the cell performance. The stability test of the cell after working for 100h shows that the tubular MCMB cathode had a perfect stability.