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.

The invention relates to a preparation method of a graphene-grafted polypyrrole nanotube/sulfur composite material for a positive electrode of a lithium-sulfur battery. The method includes the following steps of: step 1, preparing a graphene oxide-grafted polypyrrole (GOppy) nanotube; step 2, preparing a graphene-grafted polypyrrole (Gppy) nanotube; and step 3, preparing a graphene-grafted polypyrrole (Gppy) nanotube/sulfur composite material, wherein the step 3 specifically includes the following process of: placing the Gppy nanotube prepared in the step 2 and nano-sulfur powder in a ball mill, performing ball milling treatment for 2-4h, and then placing a mixture obtained by ball milling in a reaction kettle that takes polytetrafluoroethylene as a substrate under the protection of an argon atmosphere, and performing reaction for 1-20h at 100-200 DEG C to prepare a graphene-grafted polypyrrole (Gppy) nanotube/sulfur composite lithium-sulfur battery positive electrode material. The lithium-sulfur battery positive electrode material prepared by the invention can effectively inhibit the shuttle effect, and can further generally improve the electrochemical performance and cycle stability of the lithium-sulfur battery.

The invention relates to a carbon-sulfur compound for a positive electrode of a lithium-sulfur battery and a preparation and an application of the carbon-sulfur compound. The compound comprises a carbon material and elemental sulfur, wherein the carbon material has a gradient ordered three-level pore structure; the pore diameter distribution intervals of three-level pore channels are that micropores which are smaller than 2nm are taken as first-level pores, small mesopores which are about 3-10nm are taken as second-level pores and large mesopores which are 10-30nm are taken as three-level pores; the second-level pores are located in the walls of the third-level pores; the first-level pores are located in the walls of the second-level pores; pore channels of the carbon material are filled with the elemental sulfur; and the elemental sulfur accounts for 10-80wt% of total mass of the compound. The carbon-sulfur compound is applied to the lithium-sulfur secondary battery, is quite high in sulfur utilization rate and cycling stability and has the advantages of being simple in preparation process, good in repeatability, low in cost and micro-controllable.

The invention discloses a novel high-energy secondary aluminum battery. The novel high-energy secondary aluminum battery comprises a positive electrode, a negative electrode and electrolyte, wherein a positive electrode active material is a sulfur-based composite material coated with a carbon material, wherein the sulfur-based composite material is vulcanized polyacrylonitrile; the negative electrode is an aluminium-containing negative electrode, and the electrolyte is non-aqueous aluminium-containing electrolyte. The secondary aluminum battery disclosed by the invention is high in specific capacity and circulating performance; and a preparation process is simple and the novel high-energy secondary aluminum battery is suitable for industrial production.

The invention relates to a metal atom-doped porous carbon nano composite material, as well as the preparation method and the application of the metal atom-doped porous carbon nano composite material,which belongs to the technical field of lithium-sulfur batteries. The composite material comprises a porous carbon nano material matrix and metal atoms loaded on the porous carbon nano material matrix. The metal is doped in an atomic form, so that the adsorption of a host material to polysulfide can be improved. The shuttle effect of polysulfide is weakened. The composite material is used as a positive electrode material of a lithium-sulfur battery. Compared with the prior art, the lithium-sulfur battery has the advantages that the discharge rate of the battery can be improved. The excellent cycle life can still be kept during high-power discharging. The charge-discharge specific capacity and coulombic efficiency of the lithium-sulfur battery and the cycle stability of the battery are greatly improved. The purpose of manufacturing the high-power, high-capacity and long-service-life lithium-sulfur battery is achieved. In the method, the carbon source and the metal salt are wide in source and low in price. The preparation method is simple, convenient, environment-friendly, pollution-free and suitable for industrial 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 provides a lithium-sulfur battery composite positive electrode and a preparation method thereof. The lithium-sulfur battery composite positive electrode mainly comprises a mixed spraying layer of a ferroelectric material and graphene, a carbon/sulfur paste scrapping layer and a ferroelectric material spraying layer. The volume expansion of the positive electrode material during the charge-discharge process can be reduced by the two spraying layers, and the structural stability is maintained; and a long-chain polysulfide is doubly absorbed by the two spraying layers, the dissolution of the polysulfide is limited, a shuttle flying effect is effectively solved, the specific capacity of the lithium-sulfur battery is improved, and the cycle lifetime of the lithium-sulfur battery is prolonged. By a simple spraying process, a thin film layer with a controllable thickness is sprayed, and the spraying process is suitable for wide production.

The invention discloses a novel and high-energy secondary aluminum battery and a preparation method thereof. The secondary aluminum battery comprises an anode, a cathode and electrolyte, wherein the anode is made of a conducting polymer/carbon sulfur composite material, and specifically, the anode is made of a three-element composite material of graphene aerogel, conducting polymer and sulfur; the cathode adopts an aluminum-containing cathode and comprises aluminum metal or aluminum alloy; and the electrolyte adopts non-water aluminum-containing electrolyte. The secondary aluminum battery is simple and convenient to prepare and has higher energy density and longer service life.

The invention belongs to the technical field of electrode materials, in particular relates to a three-dimensional selenium/graphene foam meshed porous self-supporting flexible electrode material, a preparation method and an application. The three-dimensional selenium/graphene foam meshed porous self-supporting flexible electrode material is prepared by using a simple chemical vapor deposition technique and an impregnation method. The obtained positive electrode material is composed of elemental selenium and graphene foams; the elemental selenium is an active substance and is coated in the graphene foams to provide an active site; the electrical conductivity of the composite material is improved by the graphene foams so as to alleviate the shuttle of polyselenides; the synergistic action ofthe two components makes the self-supporting flexible electrode material exhibit high capacity and high cycle stability. The chemical vapor deposition technique and the impregnation method utilized by the invention are easy and effective, and the large-scale preparation and low-cost industrialization of the three-dimensional selenium/graphene foam meshed porous self-supporting flexible electrodematerial are easily realized.

The invention relates to a preparation method of an N/O double-doped metal carbon coated carbide nanoparticle composite material. The preparation method comprises the following steps: (1) dissolving urea in deionized water, regulating the pH value to 4-7, stirring uniformly, and drying; (2) placing the urea obtained by drying in the step (1) in a nitrogen atmosphere, annealing at high temperature,and cooling to obtain g-C3N4; (3) dissolving a metal atom precursor in deionized water to obtain a solution A, dissolving g-C3N4 in the solution A, performing ultrasonic treatment, and performing freeze drying to obtain a carbide precursor; and (4) finally, uniformly mixing and grinding the carbide precursor and zinc powder, and performing high-temperature annealing and cooling in a nitrogen atmosphere to obtain a target product. Compared with the prior art, the nitrogen-oxygen double-doped graphitized carbon in the catalytic material has the advantages that the conductivity of the catalyst is greatly improved, and dissolution of metal ions in the catalyst can be inhibited so that the catalytic performance, the cycling stability and the like of the catalyst can be greatly improved.

The present invention provides a metal sulfur battery electrolyte, which comprises a non-aqueous organic solvent, a metal salt, a first additive and a second additive. The first additive is LiNO3, andthe second additive comprises one or a plurality of compounds represented by structural formulas I-IV. The invention also provides a metal-sulfur battery, especially a lithium-sulfur battery, containing the metal-sulfur battery electrolyte. The first additive is used for protecting the metal cathode; the coulombic efficiency of the battery is improved. The second additive compound is reduced anddecomposed on the surface of the positive electrode of the battery to form a layer of positive electrode-electrolyte interface (CEI) film in the use process of the battery. The CEI membrane can effectively isolate contact between lithium polysulfide (Li2Sn, 3 < = n < = 8) generated by a battery positive electrode and an electrolyte, limit dissolution of lithium polysulfide in the electrolyte, reduce the shuttle effect of lithium polysulfide on a diaphragm and inhibit corrosion of shuttle lithium polysulfide to a lithium negative electrode, thereby improving the cycle stability of the battery.

The invention discloses a lithium-sulfur battery positive electrode composite material based on a biomass carbon source and a preparation method and application thereof, and belongs to the technical field of lithium-sulfur battery positive electrodes. Comprising a porous carbon body prepared on the basis of biomass and nano transition metal phosphide/phosphorus oxide grown on the porous carbon body in situ. The positive electrode composite material can be used for preparing a positive electrode of a lithium-sulfur battery after being subjected to sulfur loading, a precursor prepared after biomass pretreatment is soaked in a solution containing transition metal salt or a mixed solution of transition metal salt and phosphorus-containing salt, and a solid product is separated out after the precursor reacts with the solution; and performing high-temperature carbonization, pore forming and partial atmosphere treatment on the solid product to obtain the porous carbon composite material embedded with the nano transition metal phosphide.