6results about How to "Many defects" patented technology

The invention belongs to the technical field of secondary battery negative electrode materials, and particularly relates to a silicon-based negative electrode material and a preparation method and application thereof. The silicon-based negative electrode material comprises a silica frame main body structure, doped metal elements and a surface carbon coating layer. The method comprises the following steps: mixing a silicon-based compound, a metal oxide, a template agent and water, stirring at high temperature, roasting and activating at high temperature to obtain a precursor, and performing surface carbon coating on the precursor to obtain the silicon-based negative electrode material. The negative electrode material is applied to preparation of lithium ion batteries and sodium ion batteries. The silicon-based negative electrode material is nanoparticles, has a relatively large outer surface area and relatively high surface activity and is more beneficial to storage of lithium ions and sodium ions, meanwhile, the nanoparticles have a shorter diffusion path in size and are beneficial to diffusion of the lithium ions and the sodium ions, and the conductivity of the electrode material can be improved by doping metal elements and coating the surface with carbon. The material has zero strain characteristic, high energy density and excellent cycle performance in lithium ion batteries and sodium ion batteries.

The invention discloses a carbon nanotube simultaneously doped with nitrogen and phosphorus and a preparation method and application thereof, the preparation method comprises the following steps: (1) preparing a reaction liquid: adding acetonitrile into absolute ethyl alcohol, uniformly mixing, then adding triphenyl phosphate, uniformly mixing, then adding a catalyst, and finally performing ultrasonic treatment to obtain the reaction liquid; (2) air replacement: argon is introduced into the quartz tube reactor for air replacement; (3) heating reaction: after the replacement is completed, heating and introducing carrier gas, pumping the obtained reaction liquid into the quartz tube reactor after the temperature is increased to the reaction temperature, and starting the reaction; and (4) after the reaction is completed, stopping pumping the reaction liquid, maintaining the reaction temperature, reacting for a period of time, finally cooling to room temperature, and taking out the reactant, thereby obtaining the carbon nanotube product. The carbon nanotube doped with nitrogen and phosphorus elements prepared on the basis of the floating catalytic chemical vapor deposition method has excellent electrochemical performance; and the preparation process is easy for large-scale production and has an excellent application prospect.

This invention discloses a type of steel for hydropower engineering and its preparation method. The steel comprises the following chemical components: C, Mn, Si, Alt, Nb, V, Ti, Cr, Ni, Mo, Cu, and B. Its yield strength is ≥950 MPa, tensile strength is ≥1000 MPa, and it exhibits excellent load-bearing capacity, meeting the structural material requirements for high-stress conditions in large-scale hydropower projects. Its impact value at -40℃ is ≥200 J, and its aging impact value at -40℃ is ≥200 J, demonstrating excellent low-temperature toughness and aging stability. It exhibits outstanding resistance to low-temperature brittle fracture and long-term service embrittlement, providing strong service safety and durability. It is suitable for critical load-bearing structures in hydropower projects operating in cold, high-stress, and long-term service conditions.

The invention discloses a bimetal organic gel electrode material suitable for wide power fluctuation and a preparation method and application thereof.The preparation method of the bimetal organic gel electrode material comprises the following steps that transition metal nickel salt and transition metal cobalt salt are dissolved in ethyl alcohol, and transition metal salt mixed liquid is obtained; under the atmosphere of nitrogen or inert gas, dropwise adding the transition metal salt mixed solution into the terephthalic acid mixed solution at the temperature of 70-90 DEG C, continuously performing solvothermal reaction at the temperature of 70-90 DEG C to obtain a colloidal suspension, centrifuging to obtain a precipitate, washing, and performing vacuum drying to obtain the bimetallic organic gel electrode material, the bimetallic organic gel electrode material has excellent electro-catalytic hydrogen evolution and oxygen evolution activity, has low overpotential in the HER process in an alkaline environment, has the lowest overpotential of 28 mV, still keeps good stability under different large current densities, and has good electrochemical activity and wide power stability.

The invention provides a method for preparing a flat ultrathin lithium foil negative electrode based on ultrasonic rolling, and belongs to the technical field of lithium battery negative electrodes, and the method comprises the following steps: carrying out primary ultrasonic rolling treatment on a lithium strip to form a lithium foil with the thickness of not more than 20 microns; compounding the lithium foil and a current collector through a cold pressing method to form a lithium foil negative electrode A; performing secondary ultrasonic rolling treatment on the lithium foil negative electrode A to obtain a lithium foil negative electrode B; the lithium foil negative electrode B is immersed in acetone for ultrasonic vibration aging treatment, and a lithium foil negative electrode C is obtained; and immersing the lithium foil negative electrode C in acetone for cleaning, and carrying out vacuum drying to obtain the flat ultrathin lithium foil negative electrode. A two-stage ultrasonic rolling technology of first high-amplitude impact and second low-amplitude impact is introduced, the technology utilizes an energy converter to efficiently convert alternating voltage into high-frequency mechanical vibration, the double advantages of ultrasonic impact and static pressure rolling are ingeniously fused, and the defects that in the prior art, the relative error of effective thickness is large, the surface roughness is high, and the machining precision is high are overcome. And therefore, the technical defects of poor film forming effect and poor battery cycle performance are overcome.

The application provides a silicon-doped titanium lithium ion sieve and a preparation method and application thereof, and particularly relates to the technical field of ion sieve preparation. 1‑x Si x O3; wherein 0 The silicon-doped titanium lithium ion sieve provided by the application introduces silicon elements in the crystal structure, uses the high-electronegativity tetravalent silicon atoms to replace a small part of low-electronegativity tetravalent titanium atoms, breaks the regularity of rapid formation of titanium-oxygen bonds and rapid growth of [TiO6] octahedrons on one hand, controls the crystal growth speed, perfects the crystal defects at high temperature, and obtains a small-particle-size titanium lithium ion sieve precursor beta-Li2TiO3 at high temperature, and uses the higher stability of Si-O bonds than Ti-O bonds, so that the synthesized lithium ion sieve has higher acid resistance and lower titanium dissolution loss rate.