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

The invention relates to a magnesium ion doped gradient nickel cobalt lithium manganate anode material and a preparation method thereof. The chemical formula of the anode material is LiNixCoyMnzMg (1-x-y-z) O2, wherein x is more than 0.5 and less than 0.9, y is more than 0.05 and less than 0.20, z is more than 0.05 and less than 0.30, and 1-x-y-z is more than 0; the nickel content is gradually reduced from the center to the surface of the anode material particles, the manganese content is gradually increased from the center to the surface of the anode material particles, and the contents of cobalt and magnesium are uniformly distributed in the anode material. The invention also discloses a preparation method of the anode material. The anode material has the advantages that the structure and the cycle performance are stable in the charging and discharging process, the capacity is higher, and the charging and discharging reaction is highly reversible. The method has the advantages of simple process, low reaction temperature and low raw material cost, and is suitable for industrial production.

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 discloses a preparation method of a lithium-sulfur battery anode material, and relates to the technical field of lithium-sulfur batteries. The preparation method comprises the following steps of 1 cotton dipping , wherein cotton is soaked in a hydrochloric acid solution containing zinc chloride for sealed heat preservation, the redundant solution is removed, and a mixture is dried and subjected to heat preservation treatment to obtain gray or brown solids; 2 porous carbon matrix preparing, wherein carbonization treatment and acidification treatment are conducted on the solids in sequence, and then washing, drying and calcining are conducted to obtain a porous carbon matrix; 3 carbon-sulfur composite material preparing, wherein the porous carbon matrix and elemental sulfur are heated together to synthesize the lithium-sulfur battery anode material. The invention further discloses the lithium-sulfur battery anode material prepared through the method and a lithium-sulfur battery. Compared with the prior art, the lithium-sulfur battery anode material obtained through the method has the advantages of being high in sulfur loading amount and capacity, good in cycle performance, simple in process and low in cost.

The invention discloses an anode material for a non-aqueous electrolyte secondary battery, and a preparation method and application thereof. The anode material is prepared from a silicon oxide one-dimensional nano material or a carbon-coated one-dimensional silicon oxide/carbon composite material. The anode material has good electrochemical performance such as higher capacity and good multiplying and circulating performance, and has a good application prospect in the field of energy storage devices such as lithium ion batteries. During a charging/discharging process of the anode material, expansion mainly occurs in the radial direction of the one-dimensional nano material, and the expansion rate of a battery pole piece containing the active material can be reduced to 20 percent or less. According to the one-dimensional nano material provided by the invention, a synthesis technology and a carbon coating technology are simple and practical, the source of raw materials is wide, the device requirements are low, the preparation efficiency is high, and the one-dimensional nano material is suitable for large-scale popularization and application.

The invention discloses a method for preparing a porous copper current collector, and the method comprises the following steps: providing copper foil; attaching sulfur-containing dispersion liquid tothe surface of the copper foil; performing the vulcanization reaction on the copper foil to which the sulfur-containing dispersion liquid is attached; and placing the copper foil in an oxygen-containing atmosphere for oxidation thermal treatment after the sulfurization reaction; placing the copper foil in a hydrogen-containing atmosphere for reduction thermal treatment after the oxidation thermaltreatment to obtain the porous copper current collector. The porous copper current collector prepared by the preparation method has a three-dimensional porous structure, and the porous copper currentcollectors having different pore sizes and thicknesses values can be prepared by changing the preparation parameters. The battery which takes the porous copper current collector prepared by the present invention as a negative current collector has higher and more stable coulombic efficiency and a longer cycle life. The three-dimensional porous copper can effectively inhibit the formation and growth of the negative dendritic crystals and can realize deep discharge.

The invention discloses a preparation method of a lithium ion battery negative electrode material high-entropy oxide. The preparation method comprises the following steps: S1, carrying out oil removal, polishing and rust removal, distilled water washing, alcohol solution secondary washing and vacuum drying on a high-entropy alloy Cr<0.2>Fe<0.2>Mn<0.2>Ni<0.2>Co<0.2> solid; S2, conducting melting, carrying out gas atomization granulation, and conducting cooling and sieving; and S3, taking the high-entropy alloy powder, and conducting oxidation treatment under flowing oxygen, so as to obtain the required (Cr<0.2>Fe<0.2>Mn<0.2>Ni<0.2>Co<0.2>)<3>O<4> high-entropy oxide lithium ion electrode material. The lithium battery negative electrode material (Cr<0.2>Fe<0.2>Mn<0.2>Ni<0.2>Co<0.2>)<3>O<4> high-entropy oxide obtained through the method is a pure phase, the particle morphology is uniform, the particle size is 0.1-2 microns, namely, the material performance is more stable, a battery assembled by the lithium battery negative electrode material high-entropy oxide has very high specific capacity and very good cycle stability and has remarkable economic value, and the method is short in process, easy to operate, low in cost and suitable for industrial production. The method is high in controllability, good in repeatability, wide in applicability and suitable for industrial production.

The invention discloses a preparation method of an integrated all-solid-state lithium ion battery. The preparation method comprises the following steps: preparation of a solid-state inorganic electrolyte, preparation of an organic-inorganic hybrid electrolyte and preparation of the all-solid-state lithium ion battery. The method has the advantages that a certain amount of electrolyte is added intothe electrode, and the electrode is artificially infiltrated into the electrolyte, so that the active contact sites of the electrode and the electrolyte are increased, and the mutual infiltration degree of the interface of the electrode and the solid electrolyte of the all-solid-state lithium ion battery after annealing treatment is deepened; more channels are provided for lithium ion conduction,and the interface internal resistance between the prepared all-solid-state lithium ion battery electrode and the electrolyte is reduced.

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.

The invention provides a layered metal organic phosphate frame sodium ion cathode material and a preparation method thereof. The cathode material is a layered material formed by doping a carbon conductive agent in a metal organic phosphate frame sodium ion cathode material. The single crystal molecular formula of the metal organic phosphate frame sodium ion cathode material is C2H10Na2O16P2V2, andthe molecular structure belongs to a structure of the monoclinic system with the space group being a chiral non-center space group. The method is comprises the following steps: (1) adding a vanadiumsource to water, performing dispersing, adding phosphoric acid, oxalic acid dihydrate, performing stirring, adding a sodium source, and performing dispersing uniformly; (2) performing the hydrothermalreaction, performing filtering, washing and precipitating and drying to obtain an Na-MOF material; (3) mixing the Na-MOF material with a carbon conductive agent, performing grounding to obtain the cathode material. The cathode material of the invention has a large discharge gram volume, is good in rate performance, and is stable in cycle performance and coulombic efficiency. The method of the invention is low in synthesis temperature, is simple in operation, is low in cost, is high in controllability, is good in repeatability, and is suitable for industrial production.

The invention provides a carbon quantum dot and graphene composite material, and a preparation method and an application thereof. The CQD/CF composite material is synthesized by taking anhydrous citric acid as a carbon source and ferric trichloride hexahydrate as a catalyst through a simple and convenient catalytic graphite method; the CQD/CF composite material is composed of a large-specific-surface-area ultrathin graphene-shaped carbon plate and a large number of carbon quantum dots, and porous structures are distributed on the surface of the graphene-shaped carbon plate; the carbon quantum dots are distributed on the graphene-shaped carbon plate; and according to the mixed potassium double-ion capacitor, the carbon quantum dot and graphene composite material is used as a positive electrode, nano-graphite is used as a battery behavior negative electrode, 0.8 M potassium hexafluorophosphate KPF6 is used as an electrolyte, and cellulose paper is used as a diaphragm. The preparation method is simple, and the obtained carbon quantum dot and graphene composite material has excellent an anion storage capacity, excellent structural stability and excellent capacitor performance.

The invention relates to a room temperature sodium-sulfur battery positive electrode material and a preparation method and an application thereof. The preparation method comprises the steps of S1, blending polyacrylonitrile and sulfur powder, ball milling and calcining to obtain a sulfurized polyacrylonitrile precursor material; S2, polymerizing pyrrole monomers on the precursor material in situ to obtain a polypyrrole (PPy) nanolayer; S3, annealing the material obtained in the step S2 to obtain the room temperature sodium-sulfur battery positive electrode material. The surface of sulfurized polyacrylonitrile is coated with an N-doped carbon layer, thereby being capable of well playing a role of protecting and stabilizing the electrode. Meanwhile, the doping of the element N can acceleratethe kinetic process of the electrochemical reaction, reduce the polarization in the electrochemical reaction process, improve the discharge voltage platform of the battery and thus improve the energydensity of the battery. Furthermore, the positive electrode material is carbonized at a low temperature, thereby avoiding the loss of sulfur; and the obtained positive electrode material has excellent cycle performance, stable Coulomb efficiency, high specific capacity and excellent electrochemical performance.

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.

The invention discloses an iron and nickel-doped activated carbon-sulfur material. The iron and nickel-doped activated carbon-sulfur material is obtained by activating an inorganic nickel salt, an inorganic iron salt, activated carbon and sulfur as raw materials through a hydrothermal method, a liquid-phase in-situ composite method and a melting method. The preparation method comprises the following steps of (1) preparing iron and nickel-doped activated carbon powder through the hydrothermal method; (2) preparing an unactivated iron and nickel-doped activated carbon-sulfur material through theliquid-phase in-situ composite method; and (3) activating the iron and nickel-doped activated carbon-sulfur material. The iron and nickel-doped activated carbon-sulfur material is used as a positiveelectrode of a lithium-sulfur battery; when the current density is 167.5mA/cm<2>, the initial specific discharge capacity is 1,000-1100mAh/g; and after 100 cycles, the specific capacity is reduced to500-550mAh/g. The iron and nickel-doped activated carbon-sulfur material has the advantages that (1) the sulfur content is greatly improved; (2) dissolution of one part of polysulfide is successfullyinhibited; and (3) component distribution is uniform, negative electrode corrosion and internal resistance increase of the battery caused by the shuttle effect are effectively inhibited, and the effects of providing the specific discharge capacity, reducing the battery capacity attenuation rate and improving the cycle performance are achieved.

The invention discloses a preparation method of a vertical graphene/nano-silver composite material, and the method comprises the following steps: S1, spraying a graphene oxide solution on a substrate to form a horizontal graphene arrangement layer; S2, spraying a template solution and a graphene oxide solution on the horizontal graphene arrangement layer at the same time to obtain a precursor; S3, performing heat treatment on the precursor material, and then performing cleaning and drying to form an upright graphene array layer to obtain a columnar upright graphene array material; S4, dipping the columnar upright graphene array material in a nano-silver solution, and then performing drying to remove a solvent; S5, carrying out heat treatment on the columnar upright graphene array material impregnated with the nano-silver in an inert atmosphere to obtain the upright graphene/nano-silver composite material. The invention also discloses the upright graphene/nano-silver composite material prepared by the method and application thereof. The application comprises the following two aspects: application as a current collector material and application in preparation of a battery.

The invention provides application of a LiI-KI eutectic salt in a low-temperature liquid state molten salt lithium battery, and a low-temperature liquid state molten salt lithium battery and a preparation method thereof, belonging to the field of lithium batteries. The present invention provides the application of the LiI-KI eutectic salt in the low-temperature liquid state molten salt lithium battery. The eutectic temperature of the LiI-KI eutectic salt taken as an electrolyte is 260-265 DEG C so that it is achieved that the whole liquid state molten salt lithium battery can work at an operation temperature below 300 DEG C. The experiment result shows that: The low-temperature liquid state molten salt lithium battery has good charge-discharge cycles, the open-circuit voltage is 0.76V, thedischarge platform voltage is stabilized at 0.5-0.6V, the discharge platform voltage is 0.8-0.9V, and the coulombic efficiency is basically stabilized at about 97%.

The invention discloses a preparation method of a high-voltage positive electrode material with a core-shell structure. The preparation method comprises the following steps of (1) ultrasonically dispersing a nickel source, a manganese source and a lithium source in an organic solvent, stirring and dissolving to form a solution containing nickel, manganese and lithium, (2) ultrasonically dispersing the ternary positive electrode material in an organic solvent, then gradually adding the nickel-manganese-lithium-containing solution into the ternary positive electrode material solution, stirring, heating and evaporating to dryness to obtain a powder precursor, (3) drying the powder precursor, heating and sintering in an oxidizing atmosphere, and cooling to obtain a sintered material, and (4) carrying out electric activation treatment on the sintered material to obtain the high-voltage positive electrode material with the core-shell structure. The preparation process is simple and easy to implement, and the prepared high-voltage positive electrode material has the advantages that the structure is stable, the coating layer is not easy to peel off, and the electrochemical performance under high voltage is good.