54results about How to "Control specific surface area" patented technology

The invention discloses a lithium ion battery conductive additive and a preparation method thereof, and solves the technical problems of improving the conductive performance and cycle life of anode and cathode materials of a lithium ion battery. The lithium ion battery conductive additive is graphene, is black powder with grain size distribution of between 10 nanometers and 100 microns, and is a carbonaceous material consisting of single or 1,000 parallel or approximately parallel graphene lamellae. The preparation method comprises oxidization and stripping reduction. Compared with the prior art, the additive has higher electric conductivity; when the additive is applied to the electrode material, the performance of the conventional battery can be greatly improved only by a little amount; the material serving as the conductive additive has good conductive performance, is easy for dispersion, and can effectively enhance the conductive performance and the magnification charging and discharging performance of the electrode material of the lithium ion battery and prolong the cycle life; and the preparation method has low requirements for raw materials and equipment, is easy to control the process, and is suitable for industrialized production.

The invention discloses a preparation method of a porous silicon / carbon composite material. The preparation method comprises the following steps: mixing decomposable silicide and a carbon source by a ball mill, carrying out heat treatment for 4-6 hours at 300-400 DEG C first, and then carrying out heat treatment for 12-20 hours at 600-800 DEG C, wherein the heat treatment process is carried out in a mixture of a protective gas and air and the volume ratio f the protective gas to the air is (10-50): 1; and treating a product obtained after heat treatment for 1-8 hours in an acid mixture of hydrochloric acid and hydrofluoric acid, and then centrifuging and drying to obtain the porous silicon / carbon composite material. The preparation method disclosed by the invention has the advantages that the preparation process is simple and convenient, a template or reduction treatment by metals is not required, and the used raw materials are industrial finished-products, thus being convenient for industrial production; the porous silicon / carbon composite material prepared by using the preparation method is adjustable in pore and size, and has relatively high coulombic efficiency and cycle stability when being used as a cathode material of a lithium ion battery.

The invention relates to a preparation method for a nitrogen-doped porous carbon / graphene two-dimensional composite electrode material. The steps are as follows: (1) dispersing graphene oxide in a solvent in an ultrasonic manner to obtain a suspension, adding organic monomers, mechanically stirring and mixing the suspension, adding initiators to initiate the polymerization reaction, and obtaining a polymer / graphene oxide two-dimensional composite material via pumping filtration, washing, and drying after the completion of the reaction; and (2) mixing the product obtained by the step (1) with potassium hydroxide via a dry method according to a proportion and arranging the mixture into a tube furnace, performing high-temperature activation under the protection of nitrogen, and obtaining a target product via acid elution, deionized water washing, and drying of the activated product. The composite material prepared by the method is a two-dimensional structure, the pore channels of micropores are short, electrolyte ions can be rapidly diffused into the pore channels in the material from external electrolytic liquid phase, the conductivity of the composite material can be improved by graphene, and the thickness of a porous carbon layer in the composite material is adjustable.

The invention discloses a method for preparing a magnesium silicate-based composite adsorption material by a multi-element co-precipitation method. The method uses a silicate solution and a magnesium salt solution as raw materials to prepare a magnesium silicate slurry; further adding the magnesium silicate slurry to the magnesium silicate slurry Adding carbonate solution to obtain magnesium silicate magnesium carbonate composite slurry; aging, filtering and washing to obtain magnesium silicate magnesium carbonate composite filter material; finally performing drying and molding treatment to obtain magnesium silicate-based composite adsorption material. The invention adds other active ingredients to expand the application range of the material; the method of pulping can improve the uniformity and structural integrity of the composite material. The magnesium silicate-based composite adsorption material microspheres and the hollow magnesium silicate-based composite adsorption material microspheres prepared by the spray drying method have significantly improved specific surface area and adsorption performance. The specific surface area of ​​the material is further improved by adopting the rolling ball granulation method, and the obtained spherical particles of the composite adsorption material are convenient for industrial application due to their complete structure and morphology.

The invention belongs to the technical field of material preparations, and particularly relates to a treatment method of a porous carbon carrier for noble metal catalysts. The method treats the porous carbon carrier by using an oxidation reduction process, and comprises the following steps: firstly, treating the porous carbon carrier by using strong acid, then, adding a strong oxidant for oxidizing the treated porous carbon carrier to obtain oxidized form porous carbon, and at last, reducing the oxidized form porous carbon by using a reducing agent to obtain surface treatment porous carbon. By adopting the method, the specific surface area, pore passage structure and pore diameter of the carbon carrier can be improved and controlled, and meanwhile the hydrophilcity of the carbon carrier and the binding ability of the carbon carrier for the noble metal catalyst can be enhanced. By using the porous carbon loaded noble metal treated by the method, a carbon loaded noble metal catalyst with excellent comprehensive performance can be obtained. The processing method is simple, and low in cost, and can be used for scale production, and the yield is high.