46results about How to "Coulombic efficiency is stable" patented technology

The invention discloses a preparation method of hollow spherical negative electrode material vanadium phosphate / carbon for a lithium ion battery. The preparation method comprises the following steps:(1) adding a vanadium source into water, heating and stirring, then adding a high molecular surfactant, heating and stirring to obtain a precursor solution; (2) carrying out spray drying to obtain a precursor of a vanadium phosphate / carbon material; and (3) carrying out heat treatment under an inert atmosphere to obtain the material. In the hollow spherical vanadium phosphate / carbon obtained by the method, vanadium phosphate is a pure phase, the particle morphology is uniform, and the particles are spherical; according to the assembled lithium ion battery, under 0 to 3 V and 100 mA / g, the first discharge gram volume reaches up to 1073.47 mAh / g, and the coulombic efficiency is high; the first reversible specific capacity reaches 551.41 mAh / g, and the capacity retention ratio after 83 timesof circulations is 80.0%; and the method is simple in operation and low in cost, and is applicable to industrial production.

Lithium-ion battery composite negative electrode material vanadium trioxide / graphene and its preparation method. The vanadium trioxide / graphene is made by the following method: (1) adding vanadium source into an oxidation solvent, heating and stirring continuously until dissolved , to obtain solution A; (2) Add graphene oxide into solution A, and then ultrasonically disperse graphene oxide uniformly to obtain liquid B; (3) heat, perform hydrothermal reaction, wash, centrifuge, and dry to obtain a precursor; (4) Carry out heat treatment under reducing atmosphere, and it is ready. In the vanadium trioxide / graphene composite negative electrode material of the lithium ion battery of the present invention, the vanadium trioxide is a nano particle with a particle diameter of 100 to 200 nm anchored on the surface of the graphene, and the vanadium trioxide is a pure phase; the assembled lithium The ion battery has high specific capacity and excellent cycle stability, and has remarkable economic value; the method of the invention is simple in operation, low in cost, strong in controllability and good in repeatability, and is suitable for industrialized production.

A method for preparing a porous copper current collector, comprising the following steps: providing a copper foil; attaching a sulfur-containing dispersion to the surface of the copper foil; performing a vulcanization reaction on the copper foil to which the sulfur-containing dispersion is attached; The copper foil is placed in an oxygen-containing atmosphere for oxidation heat treatment; the oxidized heat-treated copper foil is placed in a hydrogen-containing atmosphere for reduction heat treatment to obtain a porous copper current collector. The porous copper current collector prepared by this preparation method has a three-dimensional porous structure, and porous copper current collectors with different pore sizes and thicknesses can be prepared by changing the preparation parameters. The porous copper current collector prepared by the present invention is used as the negative electrode current collector. The battery has higher and more stable Coulombic efficiency and longer cycle life. The three-dimensional porous copper can effectively inhibit the formation and growth of dendrites in the negative electrode, and can achieve deep discharge.

The invention provides a hollow porous tin dioxide-cuprous oxide-copper or hollow porous tin dioxide-copper integrated lithium battery negative electrode and a preparation method thereof. The lithium battery negative electrode is composed of a three-dimensional porous skeleton and a hollow column of a porous structure. There are nano-copper particles in the hollow space of the column, and the nano-copper particles divide the hollow space of the hollow column into a porous structure. Nano-copper particles, the composition of the three-dimensional porous framework is copper and cuprous oxide, or the composition of the three-dimensional porous framework is copper, and the hollow columns are evenly distributed on the surface of the three-dimensional porous framework and integrated with the three-dimensional porous framework. The three-dimensional porous and hollow space of the lithium battery negative electrode can buffer the volume expansion during charging and discharging, and the integrated structure formed by in-situ growth can effectively reduce the possibility of powdering and peeling of active particles, thereby improving the lithium storage capacity of the lithium battery negative electrode. performance.

A ternary precursor with a spherical pyramid-like structure, a positive electrode material, and a preparation method thereof, wherein the cone of the ternary precursor is long strip-shaped primary particles that grow radially, and the top of the sphere is an orderly stacked block-shaped primary particle , and form secondary aggregates; the chemical formula of the ternary precursor is Ni x co y mn (1‑x‑y) (OH) 2 , wherein, 0.3<x<0.9, 0.05<y<0.50, 0.05<1-x-y<0.50. The invention also discloses a preparation method of the ternary precursor with a radial spherical cone-like structure, an anode material and a preparation method. The ternary precursor and the positive electrode material of the present invention have regular morphology and uniform distribution, which is beneficial to the transportation of lithium ions during charge and discharge, and has stable discharge specific capacity, charge and discharge performance and Coulombic efficiency, and good cycle performance. The method of the invention has the advantages of simple process, low reaction temperature and low cost of raw materials, and is suitable for industrialized production.

The invention provides a preparation method of a stannic oxide and grapheme lamella composite material. The preparation method comprises the following steps of mixing at least one organic solvents, graphene oxide lamella hydrosol and at least one tin salt, heating the mixture at a temperature of 60 to 200 DEG C for 0.5 to 12 hours to obtain a solid substance, and heating the solid substance in the inert gas atmosphere at a temperature of 400 to 700 DEG C for 0.5 to 10 hours. The invention also provides a preparation method of a metallic tin and grapheme lamella composite material. The preparation method comprises the following step of preparing a stannic oxide and grapheme lamella composite material through the preparation method of a stannic oxide and grapheme lamella composite material, and heating the prepared stannic oxide and grapheme lamella composite material in the reducing gas atmosphere at a temperature of 400 to 1000 DEG C for 0.5 to 4 hours. The preparation methods of the invention can improve a structural stability and an electrochemical performance of a material and is beneficial to improve a high-speed charging and discharging performance and a conductivity of a composite material. The preparation methods have the characteristics of cheap and easily available raw materials, simple process, and good applicability for industrial continuous production.