39results about How to "Lower diffusion barrier" patented technology

Disclosed herein is a novel hydrogen-generating, solid fuel cartridge which may be used to provide hydrogen to a proton exchange membrane (PEM) fuel cell. The cartridge contains a mixture of the hydrogen-generating solid fuel and a catalyst. The solid fuel/catalyst mixture has a packing fraction greater than about 55 percent. Throughout the fuel/catalyst mixture is means for distributing the liquid reactant; there is also a network of hydrogen-collecting, gas permeable membranes for removing the hydrogen product from the cartridge. The hydrogen-generating solid fuel cartridge may further include a liquid reactant distribution plate for distributing the liquid reactant to the solid fuel/catalyst mixture in a substantially uniform manner. The distribution plate has distribution channels arranged in a fractal pattern.

The invention relates to a pressureless sintering preparation method for boron carbide ceramic, and coarse particle powder with the particle size larger than 2 micrometers is taken as raw materials. The method comprises the following steps that 70-80 wt % of boron carbide powder (D50>=2 micrometers), 4-8 wt% of carbon powder and 0.7-2 wt% of yttrium oxide powder are put into a ball mill mixing container, ball mill slurrying is performed after binding agents, dispersing agents and deionized water are added, and the solid phase content of obtained slurry is 25-45 wt%; the obtained slurry is prepared into granulating powder with a spray drying granulating machine; the granulating powder is pressed into green bodies by adopting a dry-pressing molding technology or isostatic cool pressing molding technology at 100-200 MPa; the green bodies are placed in a vacuum furnace, a vacuum or normal pressure sintering mode is adopted, heat preservation is performed for 0.5-5 h at the temperature of 2000 DEG C-2300 DEG C, sintering is completed, and then the boron carbide ceramic is obtained. According to the pressureless sintering preparation method for the boron carbide ceramic, due to the fact that the coarse particle boron carbide powder which is low in cost is adopted as the raw materials and the pressureless sintering technology capable of achieving scale production is adopted, the preparation cost of the boron carbide ceramic can be greatly lowered, and therefore the method is suitable for the fields of nuclear power, semiconductor equipment, armor protection and the like.

The invention discloses a cobalt-containing nickel plated steel strip serving as a lithium battery shell material and a preparation method thereof. The preparation method comprises the following procedures of: (1) pretreating a base material; (2) continuously electrodepositing a nickel-cobalt alloy plating layer on the pre-treated base material; (3) carrying out diffusion annealing treatment on the nickel-cobalt alloy plating layer under a protective atmosphere like high-purity nitrogen; (4) plating a nickel-cobalt alloy plating layer on the metal subjected to the diffusion annealing treatment again; and (5) rolling the plated nickel-cobalt alloy plating layer in a cold manner. The cobalt containing nickel plated steel strip disclosed by the invention is prepared by a special process of tightly combining the nickel-cobalt alloy plating layer and a low-carbon steel strip and then electroplating the nickel-cobalt alloy plating layer and the low-carbon steel strip, shows better corrosion resistance and can be used for shell materials of primary batteries, secondary batteries and lithium ion power cells such as 18650, 26650 and the like.

The invention relates to a pressureless sintering boron carbide ceramic preparation method of using more than 2 microns of coarse-grained powder as a raw material. The preparation method comprises the following steps: putting 70-80 wt% of boron carbide (D50 is greater than or equal to 2 microns), 4-8 wt% of powdered carbon, 0.7-2 wt% of yttrium oxide powder and the balance a binder and a dispersant into a mixing container of a ball mill, adding deionized water and ball-milling for pulping so as to obtain slurry with solid content being 25-45 wt%; preparing granulation powder from the slurry by using a spray drying granulating machine; pressing the granulation powder at 100-200 MPa by a dry pressing or isostatic cool pressing process to generate a green body; and putting the green body into a vacuum furnace, and carrying out thermal insulation at 200-2300 DEG C for 0.5-5h to finish sintering by a vacuum or pressureless sintering mode so as to obtain boron carbide ceramic. As the low-cost coarse-grained boron carbide powder is used as the raw material, manufacturing cost of the boron carbide ceramic can be reduced greatly by the pressureless sintering process for large-scale production. The boron carbide ceramic is suitable for fields of nuclear power, semiconductor equipment, armor protection and the like.

The invention provides a composite positive electrode active material and a lithium ion secondary battery. The composite positive electrode active material comprises positive electrode active material particles, and a coating material which is positioned on the external of the positive electrode active material particles for coating the positive electrode active material particles. The positive electrode active material particles are layered lithium composite oxide; the general formula of the layered lithium composite oxide is Li1+xNiaCobM (1-a-b)Y2, wherein x is greater than or equal to minus 0.1 and less than or equal to 0.2; a is greater than or equal to 0 and less than or equal to 1, b is greater than or equal to 0.05 and less than or equal to 1, and a+b is greater than or equal to 0.05 and less than or equal to 1; M is selected from one or more of Mg, Zn, Ga, Ba, Al, Fe, Cr, Sn, V, Mn, Sc, Ti, Nb, Mo or Zr; Y is selected from one or more of O, or F; the bulk structure of the coating material is P4/mbm space group; and the lithium ion secondary battery comprises the composite positive electrode active material. The lithium ion secondary battery is higher in energy density and better in cycle performance under high voltage.

The invention discloses a preparation method of a zirconium oxide-mullite porous ceramic material. The preparation method is characterized in that aluminum oxide and zircon sand are taken as main rawmaterials, yttrium oxide is taken as a stabilizer, aluminum fluoride is taken as an additive, a forming mode combining polyurethane foam dipping and gel solidification is adopted, and the zirconium oxide-mullite porous ceramic material with a needle-shaped mullite whisker structure is prepared through an in-situ synthesis technology; and a solvent in a blank is volatilized and organic substances are split at a high temperature to form a porous structure which has the characteristics of being high in porosity (greater than 80%), uniform in aperture distribution, excellent in high-temperature mechanical property and excellent in thermal impact resistance.

A method for activating two-dimensional host materials for a multivalent/polyatomic ion battery may include adding a pillaring salt in electrolyte. This process may be followed by in-situ electrochemically intercalating the pillaring ions, solvent molecules and multivalent ions into the van der Waals gap of host materials. After the activation process, the host material is transformed into an interlayer-expanded 2D material with significantly enhanced specific capacity and rate performance for multivalent ion intercalation.

The invention provides a method for preparing carbon quantum dot modified lithium-sulfur battery positive electrode materials, and belongs to the field of preparation of lithium-sulfur battery positive electrode materials. The method has the advantages that carbon quantum dots with functionalized polyethyleneimine surfaces are used for preparing lithium-sulfur battery positive electrodes, shuttling effects in battery charge and discharge procedures can be inhibited under polysulfide adsorption effects of polyethyleneimine, and accordingly the long cycle performance of lithium-sulfur batteriescan be guaranteed; the method for preparing the carbon quantum dot modified lithium-sulfur battery positive electrode materials includes simple and convenient processes, the capacity, the rates and the cycle performance of the lithium-sulfur batteries under working conditions of high load and high current density can be obviously improved, and accordingly the method has a potential application value in the field of lithium-sulfur batteries.

The invention provides an electrolyte for a metal battery and the metal battery, and belongs to the technical field of batteries. The electrolyte for the metal battery, provided by the invention, comprises a liquid electrolyte and an electrolyte additive added into the liquid electrolyte, wherein the electrolyte additive is any one or more of indium salt, tin salt, bismuth salt and germanium salt. Because metals such as indium, tin, bismuth and the like have higher electrode potential than lithium, the metal ions can be reduced on the surface of the negative electrode by the lithium, so that an SEI film containing metal components is formed on the surface of the lithium negative electrode in situ. In the circulation process, metal ions in the electrolyte have electrochemical activity, stability of a metal protective layer on the surface of the lithium negative electrode is promoted, the metal can store lithium in an alloy forming mode, and meanwhile, the formed alloy can reduce diffusion barriers during lithium deposition, promote rapid migration of the lithium ions and inhibit growth of lithium dendrites; therefore, the cycling stability of the lithium metal negative electrode is further improved.

The invention provides a composite positive electrode material with a spring-shaped lamellar structure as well as a preparation method and application of the composite positive electrode material. The composite positive electrode material comprises a carbon sheet layer and vanadium trioxide nanoparticles dispersed on the surface of the carbon sheet layer. The invention provides an aluminum ion battery composite positive electrode material with a spring-shaped lamellar structure. The composite positive electrode material adopts a carbon sheet layer as a support skeleton, and is compounded with vanadium trioxide nanoparticles, so the diffusion path of aluminum ions is reduced, and the conductivity of the composite positive electrode material is enhanced; meanwhile, a precursor material is prepared by utilizing a hydrothermal method, and is calcined at high temperature to finally obtain the composite material with the spring-shaped lamellar structure.