Zhenjun ZHOU
,
Zhiguo XIAO
,
Wei PAN
,
Zhipeng XIE
,
Xixian LUO
,
Lei JIN
材料科学技术（英）
Concrete containing short carbon-coated-nylon fibers (0.4~2.0 vol. pct) exhibited quasi-ductile response by developing a large damage zone prior to fracture localization. In the damage zone, the material was microcracked but continued to local strain-harden. The carbon-coated-nylon-fiber-reinforced concrete composites (NFRC) were found to be an intrinsically smart concrete that could sense elastic and inelastic deformation, as well as fracture. The fibers served to bridge the cracks and the carbon coating gave the conduction path. The signal provided came from the change in electrical resistance, which was reversible for elastic deformation and irreversible for inelastic deformation and fracture. The resistance decrease was due to the reduction of surface touch resistance between fiber and matrix and the crack closure. The resistance irreversible increase resulted from the crack opening and breakage of the carbon coating on nylon fiber.
关键词:
Concrete
,
null
,
null
,
null
李海
,
吕春祥
新型炭材料
石墨烯、柠檬酸和硅纳米颗粒的乙醇混合物经超声分散、乙醇挥发和热处理(800℃1 h)制备出炭涂层硅/石墨烯(Si@ C/ G)纳米复合材料。透射电镜表明,Si 纳米颗粒的表面形成了一层厚度约为2 nm 的均匀炭涂层,石墨烯片层支撑着 Si@ C 纳米粒子,且两者具有较强的相互作用。作为锂离子电池负极材料,Si@ C/ G 电极具有较高的库仑效率,在500 mA·g-1的电流密度下,100卷循环后比容量为1431 mAh·g-1,表现出优越的循环稳定性。 Si@ C/ G 优异的电化学性能归因于石墨烯片层的高导热率、高导电率和优良的机械柔韧性。
关键词:
硅纳米颗粒
,
石墨烯
,
炭涂层
,
锂离子电池
康飞宇
,
马俊
,
李宝华
新型炭材料
doi:10.1016/S1872-5805(11)60073-5
通过综述碳质材料对磷酸铁锂(LiFePO4)电极材料物理和电化学性能的影响,评述了碳质材料在不同LiFePO4/C复合电极材料中的作用及其优缺点.指出:炭膜的原位包覆和模板炭的引入,限制了LiFePO4晶粒的生长,进而提高了电极材料的电导率;而导电炭和石墨烯的引入,则是直接提高了电极材料的电导率;有机结合这两种碳质材料的复合方式将会极大改善电极材料的电化学性能.但是,为了提高电极材料的体积能量密度及其振实密度,应该最大限度地降低碳质材料在LiFePO4/C复合电极材料中的含量.
关键词:
磷酸铁锂
,
炭包覆
,
炭基体
,
导电炭
,
碳纳米管
,
石墨烯
