32results about How to "Limit dissolution" patented technology

The invention relates to a carbon-sulphur composite used for a cathode material of a lithium sulphur battery as well as a preparation method and application thereof. The carbon-sulphur composite comprises a carbon material and elemental sulphur, wherein the carbon material is formed by doping mesoporous carbon with the aperture of 2-5nm and electroconductive carbon with the aperture of 30-70nm, and the electroconductive carbon with the aperture of 30-70nm contains micropores with the aperture of 0.5-1.7nm; and the elemental sulphur accounts for 10-90wt% of the total quantity of the composite. Abundant micropores guarantee that the carbon material has larger specific surface, adsorption capacity to polysulphide is stronger, and dissolution of the polysulphide can be effectively limited, so that stability of a sulphur electrode is improved. Meso pores in porous distribution can load more sulphur active substances, electrochemical capacity of a composite material is improved, and diffusion and transmission of lithium ions and electrolyte solution can be facilitated, so that reduction polarization of the elemental sulphur is reduced and discharge plateau of the elemental sulphur is improved.

Processes and apparatuses for micro-treating iron-based alloys to transform and / or shape them and the resulting materials obtained by treating low, medium, and high carbon steel and other iron-based alloys to form at least a mixed microstructure that may contain martensite, bainite and un-dissolved carbides, and may also contain complex steel microstructures including portions of bainite, coalesced bainite, acicular ferrite, retained austenite and / or martensite along with combinations thereof by micro-treating said iron based alloy.

The invention relates to a sodium-sulfur battery positive electrode material and a preparation method thereof. The sodium-sulfur battery positive electrode material is a sulfur-titanium dioxide-carboncomposite material, and the preparation method includes the following steps: firstly, preparing a metal organic framework material MIL-125, spray-drying and compounding the metal organic framework material MIL-125 with graphene, performing carbonization treatment to obtain a titanium dioxide-carbon composite material, and then doping sulfur to prepare a sulfur-titanium dioxide-carbon composite sodium-sulfur battery positive electrode material by using a ball milling method and a hot melting method. The composite material prepared by using the method has a larger specific surface area and porosity, can limit the 'shuttle effect' of polysulfide, reduces the dissolution of intermediate products, can improve the electrochemical activity of elemental sulfur, shortens the transmission paths ofelectrons and ions, limits the dissolution of polysulfide, and improves the electrochemical reaction speed of active materials adsorbed on the surface of a carrier.

The invention discloses a carbon-sulfur composite positive electrode material of a lithium-ion battery and a preparation method of the material. The positive electrode material comprises a shell layer and a nuclear layer, wherein the shell layer comprises a conducting polymer layer; the nuclear layer comprises a sulfur layer; and a nano conducting material is uniformly distributed in the sulfur layer and comprises more than one dotted nano conducting particles and more than one linear and / or piece-shaped conducting nano materials. The preparation process comprises the following steps of: (1) after uniformly mixing the nano conducting material and the sublimed sulfur, carrying out insulating treatment in closed environments with the temperatures of being 120-300 DEG C and 300-500 DEG C in sequence, and then naturally cooling to obtain the powder; and (2) carrying out ball-milling treatment on the powder obtained by the step (1), wrapping the powder by the conducting polymer, then cleaning, and drying under the condition with the temperature of being 80-120 DEG C, thus obtaining a target product. The invention has the advantages that the service life of the sulfur positive electrode material of the lithium battery can be effectively prolonged, the cycling performance of the sulfur positive electrode material can be improved, the single carrying amount of the sulfur can be improved, and the preparation process is simple and high-efficiency, and is low in cost and easy in large-scale production.

The invention belongs to the technical field of lithium-sulfur batteries and particularly relates to a high-sulfur-content carbon-sulfur material and a preparation method thereof; the carbon-sulfur material has three-dimensional porous structure and has sulfur content up to 85%; the preparation method of the carbon-sulfur material comprises the steps of I, mixing well a water-soluble sulfate, a water-soluble carbon source and water in a preset proportion to obtain mixed solution; II, adsorbing the mixed solution with foam material, and lyophilizing to obtain a precursor; III, thermally treating the precursor at high temperature to obtain an intermediate product; IV, adding the intermediate product into the solution with trivalent iron ions, allowing full reaction to obtain an initial reaction product; V, filtering the initial reaction product, washing, and drying to obtain the high-sulfur-content carbon-sulfur material. Compared with the prior art, the high-sulfur-content carbon-sulfur material has high sulfur content and good structural stability and may be used in lithium-sulfur battery cathodes to provide significant improvement in the cycle performance and rate performance of batteries.

The invention relates to a carbon-sulfur composite for positive electrodes of lithium-sulfur batteries and its preparation and application. The composite includes carbon materials and elemental sulfur, wherein the carbon materials have a gradient ordered tertiary pore structure, and the pore diameter of the tertiary channels is The distribution range is that micropores less than 2nm are used as primary pores, small mesopores around 3-10nm are used as secondary pores, and large mesopores of 10-30nm are used as tertiary pores. The secondary pores are located on the pore wall of the tertiary pores. The primary pores are located on the pore wall of the secondary pores; the elemental sulfur is filled in the pores of the carbon material, and the elemental sulfur accounts for 10-80wt% of the total amount of the compound. The carbon-sulfur composite is used in lithium-sulfur secondary batteries, exhibits high sulfur utilization rate and good cycle stability, and has the advantages of simple preparation process, good repeatability, low cost and microscopic controllability.