The thermal fatigue behavior of C/C composites coated with the SiC/MBAS glass (MoSi2 particle-containing boron aluminosilicate glass) coating, prepared by the two-step process of the pack cementation and procoating-sintering, was investigated in present paper. The experimental results indicated that the SiC/MBAS glass coating had an excellent thermal shock resistance in air at temperature up to 1873 K. During quick thermal cycle between 1873K and room temperature in air, the decrease of mass and mechanical property of the coated C/C composites was all slight. After thermal cycle for 50 times, the mass loss of the SiC/MBAS glass coated sample was only 0.22%; additionally, the remaining ratio of strength and modulus was no less than 95.2% and 99.4%, respectively. The decrease of the mechanical property during the thermal cycle was primarily due to the damnification of the fiber/matrix interfaces and the oxidation of the coated samples with oxygen.
Li LongZeng XierongLi HejunXiong XinboXie ShenghuiZou Zizhao
One of the most important factors that limits the use of LiFePO 4 as cathode material for lithium ion batteries is its low electronic conductivity.In order to solve this problem,LiFePO 4 in situ vapor-grown carbon fiber (VGCF) composite cathode material has been prepared in a single step through microwave pyrolysis chemical vapor deposition.The phase,microstructure,and electrochemical performance of the composites were investigated.Compared with the cathodes without in situ VGCF,the initial discharge capacity of the composite electrode increases from 109 to 144 mA h g-1 at a 0.5-C rate,and the total electric resistance decreases from 538 to 66.The possible reasons for these effects are proposed.
DENG FeiZENG XieRongZOU JiZhaoHUANG JianFengSHENG HongChaoXIONG XinBoQIAN HaiXiaLI XiaoHua
