115results about How to "Increase sulfur load" patented technology

The invention provides a preparation method of an S/TiO2 composite material for an anode of a sodium-sulfur battery. The preparation method comprises the following steps: dissolving butyl titanate, a template agent and a hydrolysis inhibitor into absolute ethyl alcohol; adding a mixed solution of de-ionized water and the absolute ethyl alcohol to form semi-transparent sol; transferring the sol into a high-pressure reaction kettle to react; calcining a solid product in air to remove the template agent to obtain meso-porous titanium dioxide; dispersing the meso-porous titanium dioxide into a sodium thiosulfate solution dissolved with a surfactant; adding hydrochloric acid to react; washing the solid product by a lot of the de-ionized water and drying; and eating under the protection of an inert atmosphere to obtain the S/TiO2 composite material. The meso-porous titanium dioxide prepared by the preparation method is large in specific surface area, high in porosity and strong in adsorption capability; the electrical conductivity of sulfur can be improved and a lot of nano sulfur and polysulfide can be contained; the polysulfide can be effectively prevented from being dissolved and diffused in electrolyte, and the utilization rate of the sulfur is improved; meanwhile, the structure of the meso-porous titanium dioxide is stable and a pore channel cannot be easily damaged, so as to have buffering effects on volume expansion and retraction in a charging/discharging process of a sulfur electrode.

Compositions and methods of producing composite materials for use as a cathode in electrochemical cells. Elemental sulfur is mixed with tungsten sulfide (WS₂) to form a composite mixture. Organic comonomers may be added to the composite mixture. The composite mixture is reacted to form the composite material. Electrochemical cells with cathodes containing the composite material demonstrated improved battery performance.

The invention discloses an S@NPC/CNT composite material and a preparation method and application thereof. The S@NPC/CNT composite material is obtained from an NPC/CNT composite material by sulfur loading. The NPC/CNT composite material is composed of nitrogen doped porous carbon and carbon nanotubes in the interweaving mode. The nitrogen doped porous carbon is a carbon material derived from a Zn/Co-bimetallic organic framework. The nitrogen doped carbon material is obtained by stirring, drying, calcining and acid treatment of a methyl alcohol and water mixed solution containing zinc and/or cobalt transition metal salt, organic ligand and a carbon material, and finally the high sulfur loaded S@NPC/CNT composite material is prepared by a melt diffusion method. The material exhibits extremelyhigh sulfur content. In addition, the invention also discloses the application of the high sulfur loaded nitrogen doped carbon material prepared by the method in a lithium sulfur battery. The composite material is used for an anode material of the lithium sulfur battery. The obtained battery has high area capacity and good electrochemical performance. The efficient method for preparing the nitrogen doped carbon material with high performance and high sulfur content is provided.

The invention belongs to the field of electrochemistry and discloses multiwalled carbon nanotube/sulphur/polyaniline composite cathode material, a preparation method thereof, and the application thereof to the preparation of lithium sulphur batterypositive plates. The material adopts multiwalled carbon nanotube/sulphur/polyaniline composite cathode material and a sandwich structure; multiwalled carbon nanotube/sulphur composite material is coated with conductive polyaniline through in-situ polymerization, so that the multiwalled carbon nanotube/sulphur/polyaniline composite cathode material is formed; the multiwalled carbon nanotube/sulphur composite material is prepared through chemical co-deposition. The method is simple in technology, low in cost and high in consistency and stability of products. The material is high in electronic and ionic conductivity and high in sulphur carrying capacity, and can be applied to the preparation of lithium battery composite positive plates; the positive plate is high in cycling stability and capacity retention ratio.

The invention discloses a lithium-sulfur battery composite cathode material, a preparation method thereof and a lithium-sulfur battery. The composite cathode material is formed by compositing raw materials comprising an elemental sulfur, metal-nonmetal element co-doped conductive graphitized carbon material and a lithium-conducting polymer; during the preparation process, the metal-nonmetal co-doped conductive graphitized carbon material, the lithium-conducting polymer and the solution with the elemental sulfur are stirred and mixed, then the solvent is volatilized, and heat-treated, thereby obtaining the composite cathode material having high conductivity and capable of improving the utilization rate of an active substance sulfur. The preparation method is simple, the process conditions are mild, the production cost of the lithium-sulfur battery cathode material is greatly reduced, and industrial production requirements are met; the lithium-sulfur battery made of the composite cathodematerial has a high discharge specific capacity, a stable cycle performance and a high safety performance, without the need for a current collector, and without need to add a conductive agent and a binder.

The invention relates to high-efficiency sulfurizing hydrargyrum-removing porous nanometer carbon and a preparation method thereof, belonging to the field of chemistry. The preparation method comprises the following steps of: mixing porous nanometer carbon and sulfur, and then placing into a closed pressure vessel with dry ice or liquid carbon dioxide together; heating the closed pressure vessel to 31-200 DEG C to make the carbon dioxide reach a supercritical state, keeping for 1-48 hours, or heating the carbon dioxide to the supercritical state, then injecting into the closed pressure vesselcontaining a mixture of the porous nanometer carbon and the sulfur, and keeping for 1-48 hours; and then cooling to room temperature, and evacuating the carbon dioxide so as to prepare the sulfurizing porous nanometer carbon, wherein the mass percent of the sulfur contained in the sulfurizing porous nanometer carbon is 2-50 percent. According to the invention, high sulfurizing quantity and the quantity as well as the specific surface area of the sulfur available during hydrargyrum removal are furthest ensured by tactfully adopting the gas-liquid dual property of the supercritical carbon dioxide, and therefore an optimal hydrargyrum removing effect is achieved; in addition, the advantages of simple process, high efficiency, environment friendliness and low cost are achieved.

The invention belongs to the field of electrochemical energy and discloses a nitrogen doped porous carbon/sulfur composite positive material as well as a preparation method and an application thereof in preparation of a lithium-sulfur battery positive plate. The nitrogen doped porous carbon/sulfur composite positive material disclosed by the invention is prepared by adopting a sulfur-ammonium chemical precipitation method; three-dimensional wedged nitrogen-containing porous carbon and sulfur particles form a core-shell structure, so that the electronic and ionic conductivity of the composite positive material are improved; meanwhile, the sulfur bearing capacity is also improved, dissolution and diffusion of polysulfides are limited, and thus the circulation stability and the capacity retention rate of a composite electrode prepared from the nitrogen doped porous carbon/sulfur composite positive material disclosed by the invention can be effectively increased. The preparation method can be used for accurately controlling the content of loaded sulfur without complex pretreatment and post-treatment procedures, so that the process cost is greatly lowered, the process operation is simplified, and the consistency and the stability of the composite material are improved as well.

The invention discloses a thin-wall local graphitization porous carbon sphere material, a preparation method thereof and application thereof in a lithium sulfur battery. The porous carbon sphere material is a local graphitization porous carbon nanosphere with thin wall holes; the preparation method of the thin-wall local graphitization porous carbon sphere material comprises the steps that water-base resin, water-soluble inorganic salt, a surface active agent and transition metal salts are dissolved into water to obtain a spraying solution; the spraying solution is sprayed and dried to obtaina local graphitization porous carbon nanosphere precursor; the local graphitization porous carbon nanosphere precursor is subjected to pyrolysis to obtain the thin-wall local graphitization porous carbon sphere material. The preparation method is simple in technology and good in repeatability, the prepared thin-wall local graphitization porous carbon sphere material has the advantages of being good in electrical conductivity, large in aperture, high in specific surface area and the like, the thin-wall local graphitization porous carbon sphere material is applied to a lithium sulfur battery sulfur carrier, the high specific capacity, long cycling stability and high rate capability are achieved, and the wide application prospect is achieved.

The invention belongs to the technical field of new energy materials, and particularly relates to a zinc sulfide/rGO (reduced graphene oxide) composite material as well as a preparation method and application thereof. The preparation method of the zinc sulfide/rGO composite material containing the sulphur vacancy comprises the following steps: ZnS/GO is prepared as follows: carbon disulfide is added into a ethylenediamine water solution drop by drop, and the mixture is named as a solution A; graphene oxide GO is added into an ethylene glycol solution to be subjected to ultrasonic treatment, and the mixture is named as a solution B; the solution B is added into the solution A and continuously stirred, and then a mixed solution is obtained; a zinc nitrate solution is added dropwise into themixture while stirring; the mixed product is heated and cooled to room temperature, and then subjected to centrifuging and washing, and the dried product is ZnS/GO; then the ZnS/GO prepared in the step (1) is reduced at high temperature under the condition of argon-hydrogen combination gas, and ZnS<1-x>/rGO containing the sulphur vacancy is obtained. The invention adopts a simple and safe one-potwet chemical sulphur loading method and abandons a traditional fusing diffusing method, the loss is reduced, and the loading capacity of active sulphur is as high as 90%.

The invention relates to the technical field of nanometer materials, in particular to a sulfur/tin oxide/graphene battery cathode material, a preparation method and a lithium sulfur battery. The invention discloses a preparation method of a sulfur/tin oxide/graphene battery cathode material, comprising the following steps: Step 1, nitrogen doped graphene and a tin salt solution are hydrothermallyreacted to obtain a graphene-tin oxide nano-composite material; and Step 2: the graphene-tin oxide nano-composite material and elemental sulfur are mixed to obtain a mixture, and a vacuum melting diffusion reaction is carried out on the mixture to obtain a sulfur/tin oxide/graphene battery cathode material. The invention also discloses a sulfur/tin oxide/graphene battery cathode material preparedby the method and a lithium sulfur battery thereof. The invention solves the technical problems that the elemental sulfur in the prior art cannot be effectively utilized in the cathode material of thelithium sulfur battery, thereby leading to short service life, and poor conductivity, cycle stability and safety performance of the lithium sulfur battery.

The invention relates to a positive electrode material for a lithium-sulfur secondary battery and a preparation method of the positive electrode material. Particularly, an activated carbon material with ultra-high specific surface area and large pore volume is prepared by adopting biomass waste mangosteen peel as a raw material through pre-carbonization and potassium hydroxide activation methods;and a carbon/sulfur composite material is further prepared by adopting the activated carbon material as a carrier through a melting diffusion method. A test result shows that the initial discharge specific capacity of a positive electrode prepared from the carbon/sulfur composite material with the sulfur bearing capacity of 65% under the current of 0.5C is 870.5mAhg<->, the discharge specific capacity of the positive electrode after 100 cycles is 599.6mAhg<-1> and the discharge capacity after 100 cycles under the current of 2C is 569.2mAhg<->. The carbon/sulfur composite positive electrode material prepared by adopting the biomass waste mangosteen peel as the raw material is high in sulfur bearing capacity, good in chemical stability, high in specific capacity, good in rate capability, simple in preparation method and suitable for the lithium-sulfur secondary battery.

The invention provides a preparation method of a lithium-sulfur battery positive electrode. The preparation method comprises the following steps: uniformly mixing an active substance sulfur, a conductive agent and a binder to obtain a mixture, then adding a dispersing solvent into the mixture, and uniformly mixing to obtain electrode slurry; uniformly coating a positive electrode current collectorwith the electrode slurry to obtain a wet electrode coated with the slurry; freezing the wet electrode coated with the slurry in a low-temperature environment of -80 to -5 DEG C for 1-5 hours until the wet electrode is frozen and formed, so that the dispersing solvent in the wet electrode is solidified and crystallized to obtain a solidified electrode; placing the solidified electrode in a vacuumenvironment with the vacuum degree of 0.1-100Pa for 1-5 hours, so that solid-phase sublimation of ice crystals in the solidified electrode is carried out to obtain a solid-phase sublimated electrode;and carrying out rolling treatment on the solid-phase sublimated electrode, and controlling the porosity of the electrode to be 50-70% to obtain the lithium-sulfur battery positive electrode. The preparation method is simple, and the problem of electrode cracking in the preparation of a high-sulfur-carrying positive electrode by adopting a traditional hot drying method is effectively solved.

The invention discloses a carbon-sulfur composite positive electrode for a lithium-sulfur battery and a preparation method of the carbon-sulfur composite positive electrode, and belongs to the technical field of lithium-sulfur batteries. The carbon-sulfur composite positive electrode consists of a carbon-sulfur composite layer and a conductive carbon layer which are sequentially coated on the current collector; the carbon-sulfur composite layer is composed of a sulfur material, a carbon material I and an aqueous binder, and the conductive carbon layer is composed of a carbon material II and anorganic binder. According to the double-layer carbon-sulfur composite positive electrode prepared by the method, the construction of a high-sulfur-capacity, high-sulfur-content, high-specific-capacity and long-cycle-life high-energy-density lithium-sulfur battery can be realized. The preparation method of the composite positive electrode is simple and convenient to operate, low in cost and easy to amplify, the design and preparation of the positive electrode of the lithium-sulfur battery are effectively promoted, and a new possibility is provided for the practicability of the lithium-sulfur battery with high energy density.

The invention relates to a spherical-like nitrogen-doped reduced graphene oxide material and an application thereof, and belongs to the field of battery materials. The preparation method comprises thefollowing steps of carrying out diluting on a graphene oxide water solution and then performing ultrasonic homogenization treatment, and carrying out spray drying treatment to obtain spherical-like graphene oxide powder; and next, performing grinding and mixing with a nitrogen source, and carrying out heat preserving for 0.5-6 hours at the temperature of 600-1,200 DEG C to obtain the product. Thespherical-like nitrogen-doped reduced graphene oxide material has the advantages of high conductivity, high wrinkle, large specific surface area and hierarchical pore structure; rich functional groups can be introduced by virtue of doped nitrogen atoms, so that the adverse effects caused by serious stacking of the graphene are avoided. The material and the sulfur are compounded to serve as a positive electrode material of a lithium sulfur battery, so that the uniform dispersion of the active substance can be realized, the sulfur carrying amount can be increased, the conductivity of the electrode can be improved, the " shuttle effect " can be reduced, and finally the electrochemical performance of the sulfur positive electrode is improved.

The invention relates to a preparation method of single-crystal mesoporous Mo3N2 for a positive electrode material of a lithium-sulfur battery, wherein the preparation method comprises the steps: preparing a single-crystal MoO3 nanowire by a hydrothermal method, and preparing a single-crystal mesoporous Mo3N2 nanostructure with high specific surface area by a topological reaction method by using the single-crystal MoO3 nanowire as a starting material. Molybdenum nitride has a large number of pores, the sulfur loading capacity is improved, and the shuttle effect is inhibited. The molybdenum nitride effectively solves the problem of the volume expansion effect of the lithium-sulfur battery while significantly improving the sulfur loading capacity of the positive electrode material. Non-toxicreactants and a hydrothermal method and a topological reaction method which are simple to operate are adopted, and non-toxic and harmless sublimed sulfur powder is loaded for preparing the positive electrode material of the lithium-sulfur battery, so that the method has remarkable advantages in the aspects of environmental protection, industrial production, products and application.

The invention relates to the technical field of nanometer materials, in particular to a sulfur/iron oxide/graphene battery cathode material, a preparation method and a lithium sulfur battery. The invention discloses a preparation method of a sulfur/iron oxide/graphene battery cathode material, comprising the following steps: step 1, the nitrogen doped graphene and the ferric salt solution are hydrothermally reacted to obtain graphene-iron oxide nanocomposites; Step 2: the sulfur/iron oxide/graphene battery cathode material is prepared by vacuum melt diffusion reaction from the mixture of graphene-iron oxide nanocomposite and elemental sulfur. The invention also discloses a sulfur/iron oxide/graphene battery cathode material prepared by the abovementioned method and a lithium sulfur batterythereof. The invention solves the technical problems that the elemental sulfur in the prior art cannot be effectively utilized in the lithium sulfur battery cathode material, thereby leading to shortservice life, and poor conductivity, cycle stability and safety performance of the lithium sulfur battery.

The invention relates to an anode material for a lithium-sulfur rechargeable battery and a preparation method of the anode material. According to the specific method, biomass waste, namely a durian shell is adopted as a raw material, and after pre-carbonization, potassium hydroxide activation and other methods are adopted, an activated carbon material with an ultrahigh specific surface area and alarge pore volume is prepared; and the activated carbon material is used as a carrier, and a fused diffusion method is further adopted to prepare a carbon/sulfur composite. It is shown by an electrochemical test that the first discharge specific capacity, under a 0.5C current, of an anode prepared from the carbon/sulfur composite with sulfur capacity of 60wt.% is 1,074.23mAhg<-1>; after 100 timesof circulation, the discharge specific capacity of the anode is still 724.74mAhg<-1>; and the carbon/sulfur composite anode material, which is prepared by using the biomass waste, namely the durian shell as the raw material, has the advantages of being high in sulfur capacity, good in chemical stability, high in specific capacity, excellent in rate capability, simple in preparation method and thelike and can be well applied to the lithium-sulfur rechargeable battery.

The invention provides a sulfur/dual layer titanium dioxide composite material and a preparation method and applications thereof. Dual layer titanium dioxide nano spheres are designed and then doped by sulfur to prepare the sulfur/dual layer titanium dioxide composite material. The obtained sulfur/dual layer titanium dioxide composite material can be used as a cathode material of a lithium-sulfurbattery; the amount of loaded sulfur of the cathode material is increased, the discharge-charge intermediate product can be adsorbed, thus the volume expansion and shuttling effect during the discharge-charge process can be reduced, and the electrochemical properties and circulation stability of the composite material are good.