533results about How to "Improve Capacitive Performance" patented technology

The invention discloses a lithium-sulfur battery cathode material and a preparation method thereof. The cathode material is formed by in-situ compositing of a mesoporous metal-organic framework and elemental sulfur. The mesoporous metal-organic frame is of a laminated pore structure consisting of a macro pore, a meso pore and a micro pore, wherein the pores are communicated with one another. The structure can adsorb more elemental sulfur and can simultaneously inhibit the dissolution of sulfur elementary substance and multi-sulfur compounds in electrolyte, so that the cycle performance of a lithium-sulfur battery is improved and high utilization rate of an active substance of the cathode material is kept. A sulfur and metal-organic framework material composite cathode material is prepared by a two-step process of low-temperature liquid phase composition and sulfur extraction, a composite material precursor with homogeneously dispersed high load sulfur content can be obtained through in-situ compositing at a low temperature with a liquid-phase preparation method, redundant sulfur on the surface of the precursor and in pore passages is extracted by an organic solvent, the aperture of the composite material can be further effectively adjusted and controlled, selective distribution of sulfur is realized, and the composite material with excellent electrochemical performance is obtained. By adopting the preparation method, the distribution of the sulfur in the composite material can be effectively improved, and the electrochemical performance of the composite material is optimized. Meanwhile, the preparation method is simple and is easy to perform industrially, and mass production is facilitated.

Nitrided valve metals are described, such as nitrided tantalum and nitrided niobium. The nitrided valve metals preferably have improved flow properties, higher Scott Densities, and / or improved pore size distribution which leads to improved physical properties of the valve metal and improved electrical properties once the valve metal is formed into a capacitor anode. Processes for preparing a nitrided valve metal are further described and involve nitriding the valve metal at a sufficient temperature and pressure during a heat treatment that is prior to the deoxidation step. Capacitor anodes and other products incorporating the valve metals of the present invention are further described.

The invention discloses a method for preparing a stannic oxide battery anode material on a carbon nano tube by using an electro-deposition process. The method comprises the steps of: making electro-deposition solution, treating the solution with water bath, preparing the carbon nano tube pole piece, pressing on a foam nickel base, putting the base carrying the carbon nano tube pole piece into the electro-deposition solution so as to perform vacuum treatment, and then perform the electro-deposition treatment under a constant current on the vacuumized pole piece so as to acquire the battery anode material on the carbon nano tube carrying the stannic oxide. The battery anode material prepared by using the method has higher power property and has a quality specific capacity kept between 350 and 450 F / g under a high scanning speed of 200 mV / s. The material applied in a super capacitor has higher volumetric properties, excellent cycling stability and long cycling life, first discharging specific capacity ranged between 410 and 588 F / g under a constant current density of 15 A / g, cycling times more than 5000 times and specific capacity retention rate ranged between 90 to 95 percent.

The invention provides a method for preparing a graphene / nanocarbon particle composite. The method comprises the steps that (1) graphite is oxidized to prepare oxidized graphene, and the acquired oxidized graphene is added to water to prepare suspension liquid; (2) nanocarbon particles are added to water solution with a surface active agent to acquire suspension liquid of the nanocarbon particles; (3) the suspension liquid of the oxidized graphene is mixed with the suspension liquid of the nanocarbon particles, and then mixed suspension liquid is acquired; (4) the uniformly mixed suspension liquid is spray-dried to acquire powder; (5) reduction treatment is conducted on the powder acquired in the step (4), or the powder acquired in the step (4) is placed in an inert gas atmosphere, thermal pretreatment is conducted on the powder acquired in the step (4), then reduction reaction is conducted in a reducing atmosphere, and eventually the graphene composite loading the nanocarbon particles is prepared. The invention further relates to the graphene / nanocarbon particle composite acquired by the method and application of the graphene / nanocarbon particle composite being used as materials of supercapacitors, catalyst carriers and infrared optical materials.

The invention relates to a graphene hollow nano fiber and a preparation method thereof. The external diameter of the graphene hollow nano fiber is 7-700nm, the internal diameter is 6-698nm, the length-diameter ratio is 20:1-2000:1, and the specific area is 300-2600 m<2> / g. The preparation method comprises the following steps: by using an inorganic fiber as a template, heating to 400-1000 DEG C in a carrier gas, introducing a carbon source, and decomposing at the same temperature to directly form the graphene hollow fiber or form a carbon-inorganic template composition fiber; and cooling the composition fiber, treating with acid or alkali, filtering, washing and drying. The preparation method is simple; and the product has the advantages of high purity, complete structure and high mechanical strength, and is suitable to be used as a separation or adsorbing material, an electrode material for electrochemical energy storage or a conducting agent.

The invention discloses a carbon compound cathode material for an ultracapacitor battery, comprising a nuclear layer and a shell layer, wherein the shell layer accounts for the total weight of 10-40 percent; the nuclear layer is made of graphite materials subjected to surface nanometer treatment; and the shell layer is made of a porous carbon material. The surface nanometer treatment of the nuclear layer is to form a nano carbon fiber, a cabon nanotube or a nano hole on the surface of natural graphite, artificial graphite or an in intermediate phase carbon microsphere material in situ; and the porous carbon material comprises a three-dimensional structure that millipores are distributed on a carbon organism. Metal elements are doped in the shell layer. The component formula is reasonable; the prepared material has the nuclear and shell structures in which the metal elements are doped; meanwhile, the invention has favorable characteristics of energy accumulation by using double electric layers and lithium ion stripping / embedding, can effectively improve the high multiplying power and the power density of a lithium ion battery, meets the double requirements of the ultracapacitor battery on energy accumulation by using the lithium ion and double electric layers of the cathode material, can be used as a cathode of a high-performance lithium ion battery, and has favorable high multiplying power charge-discharge performances and industrial prospect.

The invention discloses a high-performance silicon monoxide / amorphous carbon / graphite composite negative electrode material. The high-performance silicon monoxide / amorphous carbon / graphite composite negative electrode material comprises the following components in parts by weight: 5-7 parts of silicon monoxide, 1-2 parts of carbohydrate and 1-4 parts of natural flake graphite. The preparation method of the composite negative electrode material comprises the following steps of: mixing the materials; carrying out high-energy ball milling and high-temperature pyrolysis; and grinding and sieving to obtain the composite material. The composite negative electrode material is excellent in cycle performance and capacity performance, so that a certain feasibility choice is provided for practicability of the SiO negative electrode material. Moreover, the preparation method is simple to operate, environment-friendly, pollution-free and easy to popularize.

The invention provides a method for preparing a grapheme / carbon composite material. The method comprises steps of mixing and reacting aniline monomer, an oxidant and mesomorphic grapheme oxide, obtaining a grapheme oxide / polyaniline compound, mixing and reacting the obtained grapheme oxide / polyaniline compound and an activating agent and obtaining the grapheme / carbon composite material. The aniline monomer and the mesomorphic grapheme oxide serve as raw materials and are mixed completely, polyaniline is produced among layers of grapheme oxide, the agglomeration phenomenon during the grapheme activating process can be avoided effectively, the polyaniline attached to grapheme surfaces forms a multi-hole carbon material through the activating treatment, and the prepared grapheme / carbon composite material has good capacitive and cycle performance.