31results about How to "High first reversible capacity" patented technology

The invention discloses a preparation method of spherical graphite by natural crystalline flake graphite with a median diameter of 3 to 10 mu m. A five-level powder refining machine set consisting of an air-flow vortex powder refining machine and a cyclone separator is sequentially connected with a fourteen-level nodulizing machine set consisting of an air-flow vortex nodulizing machine and a nodulizing classifier in series; the graphite material enters from the first powder refining machine set and then flows through the five powder refining machine sets and the fourteen nodulizing machine sets in turn and finally out of the last nodulizing machine set; and by refining and nodulizing the powder, the spherical graphite product is obtained. The spherical graphite product has a surface closed end part structure, is spherical, and has the specific surface area of 8.0 to 12m2 / g. The number of openings on the surface of the graphite powder is 9-80 per mu m. The sphericity of the product is high; the battery capacity, the standby time and the service life are effectively increased; moreover, the preparation method can improve the yield by over 80 percent, lower the cost by 40 to 50 percent, save the power consumption by 55 percent and realize the dust recovery rate up to 100%.

The invention relates to a carbon-carbon multi-component negative electrode material. The carbon-carbon multi-component negative electrode material is mainly composed of flexible graphite, nanometer silicon and amorphous carbon which respectively account for 30-60%, 30-50% and 10-30% based on mass percent, the amorphous carbon is obtained through high-temperature pyrolyzation of an organic carbon source, and the flexible graphite is obtained by applying pressure to expanded graphite. A preparation method of the product comprises the steps of: firstly, preparing an expanded graphite / silicon-silicon dioxide / carbon composite negative electrode material through high-temperature pyrolyzation; secondly, pouring the expanded graphite / silicon-silicon dioxide / carbon composite negative electrode material into a mould and applying pressure to obtain a flexible graphite / silicon-silicon dioxide / carbon composite negative electrode material; thirdly, processing silicon dioxide to obtain a flexible graphite / silicon / carbon composite negative electrode material through etching by a corrosive liquid; and finally, using asphalt to permeate a gap inside the flexible graphite / silicon / carbon composite negative electrode material in a protective atmosphere, and obtaining the product after high-temperature heat treatment and repetition. The carbon-carbon multi-component negative electrode material has the advantages of high capacity, high coulombic efficiency, good cycle performance, structure stability, high reversible capacity and the like.

The invention discloses a silicon-cobalt-carbon composite material for a negative electrode of a lithium ion battery and a preparation method of the silicon-cobalt-carbon composite material. The preparation method comprises the following steps of uniformly dispersing nanometer silicon powder in water to obtain a nanometer silicon powder dispersing solution; adding a cobalt source into the nanometer silicon powder dispersing solution, dissolving the cobalt source, adding citric acid monohydrate, dissolving the citric acid monohydrate, adding graphite, and uniformly mixing the graphite to obtain a mixed solution; adjusting pH of the obtained mixed solution to be 2-5, precipitating a metal cobalt complex wrapping nanometer silicon powder particles from the surface of graphite powder particles to obtain a colloidal solution; carrying out drying and thermal processing on the obtained colloidal solution to obtain the silicon-cobalt-carbon composite material, wherein the mass ratio of the nanometer silicon powder to the cobalt source is (1:1) to (1:2), the mass ratio of the citric acid monohydrate to the cobalt source is (1:1) to (1:2), and the mass ratio of the nanometer silicon powder to graphite is (1:3) to (1:10). The silicon-cobalt-carbon composite material is environmental-friendly and is low in cost, the initial reversible capacity of the battery also can be effectively improved, and the cycle lifetime of the battery can be effectively prolonged.

The invention belongs to the field of new energy materials, and relates to a silicon-carbon composite negative electrode material and a negative electrode sheet, a preparation method thereof, and a lithium ion battery. The preparation method of the silicon-carbon composite negative electrode material includes: S1, dispersing phenol and / or aminophenol, formaldehyde and silicon precursor material in an alcohol-amine mixed aqueous solution, vigorously stirring the reaction at 20-90 ° C for at least 20 minutes, solid-liquid Separating and drying to obtain a silica / phenolic composite with a fractal structure; S2, calcining the silica / phenolic composite in the presence of magnesium powder and / or aluminum powder to obtain a silicon-carbon composite material with a fractal structure. When the silicon-carbon composite material is used as a negative electrode material for lithium-ion batteries, it can well overcome the failure caused by the volume change during charging and discharging, maintain a good conductive network, reduce volume expansion, improve the first reversible capacity and the first Coulomb efficiency, reduce the First cycle capacity loss and improved cycle stability.

The invention discloses a preparation method of spherical graphite with a median diameter of 6 to 14 mu m. A five-level powder refining machine set consisting of an air-flow vortex powder refining machine and a cyclone separator is sequentially connected with a fourteen-level nodulizing machine set consisting of an air-flow vortex nodulizing machine and a nodulizing classifier in series; the graphite material enters from the first powder refining machine set and then flows through the five powder refining machine sets and the fourteen nodulizing machine sets in turn and finally out of the last nodulizing machine set; and by refining and nodulizing the powder, the spherical graphite product is obtained. The spherical graphite product has a surface closed end part structure, is spherical, and has the actual density of 2.28 to 2.3g / cm<3>. The number of openings on the surface of the graphite powder is 9-80 per mu m. The sphericity of the product is high, the electrochemical performance is obviously improved, and the battery capacity, the standby time and the service life are effectively increased; moreover, the preparation method can improve the yield by over 85 percent, lower the cost by 45 percent, save the power consumption by 40 percent and realize the dust recovery rate up to 100%.

The invention belongs to the field of new energy materials, and relates to a silicon-carbon composite negative electrode material and a negative electrode sheet, a preparation method thereof, and a lithium ion battery. The preparation method of the silicon-carbon composite negative electrode material includes: S1, dispersing hollow silica microspheres or carbon particle materials coated with silica layers, phenol and / or aminophenol, formaldehyde and silicon precursor materials in In the mixed aqueous solution of alkanolamine, the reaction is vigorously stirred at 20 to 90 ° C for at least 20 minutes, the solid-liquid is separated, and dried to obtain a silica / phenolic composite material with a fractal structure on the surface; S2, the silica / phenolic composite material is placed in magnesium calcined in the presence of powder and / or aluminum powder. When the silicon-carbon composite material is used as a negative electrode material for a lithium-ion battery, it can well overcome the failure caused by the volume change during charging and discharging, maintain a good conductive network, reduce volume expansion, improve the first reversible capacity and the first Coulomb efficiency, and reduce the first time Cycling capacity loss and improved cycling stability.

The preparation method of spherical graphite with a median diameter of 3-10 μm adopts a five-stage powder refinement unit composed of an airflow vortex powder refiner and a cyclone separator, and an airflow vortex spheroidizer and spheroidizer The fourteen-stage spheroidizing units composed of the device are connected in series in sequence. The graphite raw material enters from the first powder refining unit, flows through five powder refining units and fourteen spheroidizing units in turn, and is finally The unit flows out, and the spherical graphite product is obtained through the powder refinement and spheroidization process, which has a closed end structure on the surface. The shape of the graphite powder is spherical, and its specific surface area is 8.0-12m2 / g. The number of openings is 6-65 / μm. The sphericity of the product is good, and the electrochemical performance is significantly improved; the battery capacity, standby time and service life are effectively improved; the preparation method can increase the yield by more than 90%, reduce the cost by 50%, save power consumption by 60%, and recover dust Rate 100%.