1503results about How to "Good electrical conductivity" patented technology

The invention relates to a composite silicon negative electrode material. The composite silicon negative electrode material comprises nanometer silicon, a nanometer composite layer coating the surface of nanometer silicon and a conductive carbon layer uniformly coating the nanometer composite layer, wherein the nanometer composite layer is silicon oxide and metal alloy. According to the composite silicon negative electrode material with a three-layer structure, the nanometer composite layer composed of the silicon oxide and the metal alloy coating the surface of the silicon oxide effectively reduces volume expansion of the nanometer silicon, maintains the characteristic of high conductivity of the silicon material, improves mobility of lithium ions, prevents direct contact between a silicon negative electrode and an electrolyte, and can form a hard SEI film on the surface of the composite silicon negative electrode material, thereby allowing the cycle performance of the material to be substantially enhanced. The composite silicon negative electrode material has the characteristics of high capacity (greater than 1500 mAh / g), long cycle life (with a capacity retention ratio of more than 90% after 300 cycles) and high conductivity. The preparation method for the composite silicon negative electrode material is simple, easily controllable, and applicable to industrial production.

The invention relates to a cement-based material of carbon nano tube fiber and a preparation method thereof, in particular to a toughened cement-based material and a preparation method thereof. The invention solves the problems of relatively low anti-bending and anti-breaking intensity and toughness of the existing fiber toughened cement-based material. The material is produced by a fiber dispersant, an organic solvent, carbon fibers, carbon nano tubes, deionized water, a superplasticizer, a polymer emulsion, mineral admixture and cement. The preparation method of the invention is as follows: the fiber dispersant is added into mixed slurry of the cement and stirred; the primarily mixed slurry is fed into a high shearing colloid mill for shearing at high speed for 5 to 30min; the evenly stirred slurry is poured into a test mould which is moved to a vacuum drying case for pressure reducing and bubble-removing and heated for evaporation of the solvent for 0.5 to 3 hours; after 24 hours, and the material is obtained after tearing the mould and maintained in water at room temperature. The fracture energy GF and the fracture toughness of the material obtained by using the method of the invention respectively are 106.3N question mark m and 0.998Mpa / m<-1 / 2>, which are respectively 112.6 percent and 33.1 percent higher than the fracture energy and the fracture toughness of the existing fiber toughened cement-based material.