18results about How to "Lower diffusion barrier" patented technology

The invention relates to the technical field of electrochemistry, in particular to a high-entropy Prussian blue analogue positive electrode material, a preparation method and application. Preparing manganese source, iron source, cobalt source, nickel source and copper source solutions; the preparation method comprises the following steps: dispersing a potassium ferrocyanide precursor and a potassium citrate chelating agent in deionized water, adding quantitative manganese source, iron source, cobalt source, nickel source and copper source solutions after uniformly dispersing, and continuously stirring in the adding process until all the solutions are dropwise added; centrifugally washing the obtained mixed solution by using deionized water and absolute ethyl alcohol; drying the centrifugally washed colloid in a vacuum drying box; the obtained solid particles are ground into uniform powder, and the high-entropy Prussian blue analogue positive electrode material is prepared by adopting the preparation method; the material can be used as a sodium ion battery positive electrode material. The content of crystal water is reduced, and side reactions in the electrochemical process are reduced. Excessive crystal defects are improved; the structural stability is improved; and the sodium ion diffusion barrier is reduced.

The invention belongs to the technical field of lithium cobalt oxide positive electrodes, and discloses a high-entropy doped lithium cobalt oxide positive electrode material as well as a preparation method and application thereof. The molecular formula of the high-entropy doped lithium cobalt oxide positive electrode material is LiCo (1-y) MgxAlyPrzTi (0.0025) O2 or LiCo (1-y) MgxAlyNdzTi (0.0025) O2, x is greater than or equal to 0.001 and less than or equal to 0.01, y is greater than or equal to 0.001 and less than or equal to 0.01, and z is greater than or equal to 0.001 and less than or equal to 0.01. The high-entropy doped lithium cobalt oxide positive electrode material disclosed by the invention is formed by combining a surface integration layer and bulk phase doping, so that irreversible transformation of a material structure from an O3 phase to an O1-O3 blended phase (H1-3) is inhibited, and slippage of a transition metal layer and collapse and irreversible phase transformation of an O3 lattice structure are prevented; the stability of a surface interface and a bulk phase structure of the lithium cobalt oxide positive electrode material under high voltage is improved, and the lithium cobalt oxide positive electrode material can be applied to a lithium ion battery.

The invention discloses a preparation method and application of a two-dimensional composite material. The preparation method comprises the following steps: adding MXene into formamide, carrying out ultrasonic dispersion to obtain an MXene formamide dispersion liquid, then adding MgAl LDH into the MXene formamide dispersion liquid, carrying out magnetic stirring, washing with absolute ethyl alcohol, and carrying out vacuum drying to obtain a two-dimensional composite material which is marked as MgAl LDH / MXene. The two-dimensional composite material is used for a lithium-sulfur battery diaphragm barrier layer so as to inhibit the shuttle effect of polysulfide. The preparation method is simple and environment-friendly, and the prepared MgAl LDH / MXene two-dimensional composite material is high in specific surface area, has strong affinity to polysulfide, can promote rapid transmission of lithium ions, can provide an instant electron conduction way for adsorbed polysulfide, is applied to a diaphragm barrier layer of a lithium-sulfur battery, and has a good application prospect. The wettability of the electrolyte on the diaphragm and the conversion of polysulfide are enhanced, the problem of volume expansion in the cycle process of the lithium-sulfur battery is relieved, and the redox reaction kinetics is accelerated.

The invention provides a molybdenum-niobium-tungsten-oxygen fast-charging negative electrode material and a preparation method and application thereof.The preparation method includes the steps that a molybdenum source, a niobium source, a tungsten source and an organic solution are subjected to dehydration treatment to obtain an organic-inorganic mixed solid, and the molybdenum-niobium-tungsten-oxygen fast-charging negative electrode material and micron-sized secondary particles composed of nano-particles are prepared through a high-temperature calcination method. The conductivity and the ion diffusion rate are improved by utilizing a low-crystallinity crystal structure, the capacity retention rate is 87% after 2000 cycles at the high rate of 50C, and meanwhile, the problem of low compaction density of nanoparticles is avoided. The method is simple in process, low in energy consumption and loose in preparation condition, avoids harsh conditions, and has practical application value.

The application belongs to the technical field of lithium batteries, and discloses a gel electrolyte taking a functionalized two-dimensional MXene material as a dispersant as well as a preparation method and application of the gel electrolyte. The gel electrolyte comprises a functionalized MXene material and a basic electrolyte; the functionalized MXene material is obtained by the following method: 1) treating a MAX phase material with a solution containing HCl and LiF, intercalating, peeling off, and then reacting with a diazonium salt solution to obtain a sulfonic acid functionalized MXene material. The application further discloses a preparation method of the gel electrolyte. The application reconstructs a lithium ion solvation structure, reduces a desolvation energy barrier, homogenizes a bulk phase electric field and ion flow, cooperatively induces formation of a stable SEI interface rich in inorganic species, significantly inhibits lithium dendrite growth, and improves interface kinetic stability. The method is simple and low in cost. The electrolyte is used in a lithium metal battery and exhibits excellent cycle performance.

The invention relates to the technical field of semi-solid batteries, in particular to a negative electrode, a preparation method of the negative electrode and a battery. The negative electrode comprises a current collector, a negative electrode active material layer arranged on the current collector and a polymer layer arranged on the side, away from the current collector, of the negative electrode active material layer, the polymer layer comprises an inorganic compound and a polymer, the chemical formula of the inorganic compound is Ax-ByFz, x is larger than or equal to 1, y is larger than or equal to 1, z is larger than or equal to 3, and x is larger than or equal to 1. A is at least one of magnesium, aluminum and zinc, B is at least one of lithium or sodium, and F is fluorine. According to the invention, the polymer is combined with the inorganic compound with the chemical formula of Ax-ByFz, so that cracks generated by the interfacial film due to the change of the volume of the negative electrode in the use process can be avoided, the service life is prolonged, the cycle performance is improved, and meanwhile, the lithium / sodium ion transfer number is increased, so that the electrochemical performance of the battery is remarkably improved.

This invention discloses a method for preparing hard carbon materials for high-rate cycling sodium-ion battery anodes and their applications, relating to the field of energy storage materials technology. The invention uses phenolic resin prepolymer and melamine-formaldehyde prepolymer with a specific degree of polymerization as precursors, constructs a three-dimensional cross-linked network via a solvothermal method, and employs a stepped variable-temperature carbonization process including low-temperature polycondensation, medium-temperature pore-forming, and high-temperature reforming stages. This method utilizes a structure-directing agent to form a closed-pore structure through in-situ decomposition and precisely controls the carbon interlayer spacing. The prepared hard carbon material possesses short-range ordered pseudo-graphite microcrystals and a suitable interlayer spacing (0.38nm-0.42nm). When used as a sodium-ion battery anode, it exhibits a reversible specific capacity higher than 400mAh / g, an initial coulombic efficiency exceeding 92%, and a capacity retention rate greater than 90% after 1000 cycles at 5C high rate. This invention solves the problems of poor rate performance and low initial efficiency of existing hard carbon materials, making it suitable for high-power energy storage devices.

The invention provides a method for prolonging the cycle life of a conversion reaction positive electrode battery based on large-current pulse activation. According to the invention, a conventional low-current constant-current activation mode is replaced by a specific charge-discharge system activation method for the conversion reaction positive electrode battery; a conversion reaction positive electrode is repeatedly stimulated, a product is regulated and controlled to be uniformly nucleated, a stable reaction interface is formed, a homogeneous reaction of the product is smoothly realized, a diffusion barrier of a two-phase product reaction is reduced, and a discharge product is promoted to be fully converted into an active substance material; and the volume expansion of the pole piece is effectively inhibited, so that the problems of capacity attenuation and unstable cycle performance of a conversion reaction positive electrode battery caused by inactivation, falling and passivation of active substances are improved. Besides, compared with a traditional low-current activation system, the charging and discharging system provided by the invention shortens the time and can promote the battery to quickly reach the optimal performance state, so that the commercialization value is further improved for the application of the battery.

The invention provides a P2 type sodium ion battery positive electrode material and a preparation method thereof, the P2 type sodium ion battery positive electrode material is of a core-shell structure and comprises a NaaNixMn2xGdyBazO2 material as a matrix core and a conductor coating layer coating the surface of the matrix core material, the conductor coating layer material is a mixture of Ti (HPO4) 2 and MgHPO4, 0.6 < = a < = 0.7, 0.005 < = y < = 0.02, 0.001 < = z < = 0.01, and 3x + y + z = 1. The P2 type sodium ion battery positive electrode material has excellent rate capability and cycle performance under high voltage.

The application provides a GaN-based light-emitting diode epitaxial structure and a preparation method thereof, wherein a Zn source is introduced as a surface activator during the growth of a P-type AlGaN electron blocking layer, a P-type AlGaN electron blocking layer structure with a gradient distribution of Zn concentration along the direction of the P-type AlGaN electron blocking layer is constructed, and specifically, through the core role of the Zn surface activator and the innovative design of the gradient distribution of the Zn concentration, the valence band Ev is smoothly and non-peaked along the whole process, and the hole injection is smooth along the whole process under the premise of ensuring that the conduction band Ec is smoothly and non-peaked and the strong electron blocking capability is not lost.

The present application relates to the technical field of battery materials, and in particular to a negative electrode material and a preparation method thereof and a sodium ion battery. The negative electrode material comprises a transition metal sulfide and nitrogen ions and selenium ions doped in the transition metal sulfide. The present application improves the intrinsic conductivity of the transition metal sulfide by nitrogen doping, and the introduction of selenium can expand the ion transmission channel. Through the advantages of the two anions of nitrogen and selenium, the rate performance and cycle stability of the transition metal sulfide negative electrode material are improved without reducing its capacity. Therefore, the negative electrode material has a good application prospect.

This invention relates to the field of batteries and discloses a method for preparing nickel disulfide / copper sulfide / carbon composite hollow spheres and their applications. The invention uses hollow spherical Ni-MOF as a precursor, combined with subsequent ion exchange, PDA coating, glucose coating, carbonization, and sulfidation to prepare nickel disulfide / copper sulfide / carbon composite hollow spheres. This material inherits the porous hollow structure of Ni-MOF, providing a high-speed and efficient transport channel for ion diffusion in electrode materials, while mitigating volume change effects and improving the cycle life of sodium-ion batteries. Furthermore, the controllable introduction of appropriate amounts of copper ions through ion exchange to form a nickel-copper bimetallic sulfide heterostructure can accelerate ion diffusion kinetics, reduce the ion diffusion barrier, and enhance structural stability. Finally, the nitrogen-doped carbon derived from polydopamine carbonization in the middle layer improves the conductivity of the composite material and increases sodium storage active sites, while the outermost carbon layer derived from glucose carbonization further enhances the structural stability of the composite material.

The invention relates to the technical field of membrane separation, and discloses a preparation method of a high-performance solid electrolyte membrane Joule hot pressed sintering. According to the method, a Joule hot pressing sintering process is adopted, solid electrolyte powder is taken as a raw material, a proper amount of powder is weighed and put into a mold of Joule hot pressing equipment, and pressure is applied to an upper graphite plate and a lower graphite plate in a vacuum or inert gas environment. Through the synergistic effect of external pressure and Joule heat, the temperature of the material can be rapidly increased to 800-1500 DEG C in an extremely short time, and heat-preservation sintering is completed, so that the sintering period is remarkably shortened, the preparation efficiency is improved, and a compact and high-performance solid electrolyte membrane is obtained. Compared with a traditional heating furnace which needs at least more than 3 hours in heating time and Joule hot pressing is controlled within 1 minute, the heating time can be effectively shortened by at least 90% or more, and the prepared solid electrolyte membrane has high density and low defects, shows excellent ion separation performance and is suitable for industrial production. And a reference thought is provided for related fields such as efficient recovery and extraction of lithium resources.

The present invention provides a lithium ion battery biomass-based hard carbon negative electrode material and a preparation method thereof, the preparation method comprising the following steps: S1. cutting balsa wood into wood blocks, immersing the wood blocks in a sodium chloroacetate alkaline solution, taking them out and repeatedly washing them with deionized water, freeze-drying them to obtain an absolutely dry pre-treated wood block; S2. vacuum-immersing the pre-treated wood block in a ferrous ion solution, keeping it at a constant temperature for 2-4 hours, and then transferring it to a potassium nitrate alkaline solution, reacting it at a constant temperature for 5-7 hours, repeatedly washing the reactant with deionized water, freeze-drying it to obtain a magnetic Fe3O4-modified wood block; S3. vacuum-immersing the magnetic Fe3O4-modified wood block in a precursor solution, placing it in a magnetic field for magnetic induction heating, repeatedly washing the reactant, freeze-drying it to obtain a precursor; S4. carbonizing the precursor. The lithium ion battery biomass-based hard carbon negative electrode material prepared by the present invention has excellent rate performance, cycle performance and high specific capacity.

This invention belongs to the field of electrochemical power source technology, and relates to a multi-metal ion-substituted V site M x V₂O₅ materials, their preparation methods, and applications. The preparation steps are as follows: Citric acid monohydrate, anhydrous oxalic acid, and ammonium metavanadate are sequentially added to deionized water and stirred until completely dissolved to obtain a first solution; citric acid monohydrate and a salt containing metal cation M are added to deionized water and stirred until the salt containing metal cation M is completely dissolved to obtain a second solution; the two solutions are mixed evenly and reacted under a preset temperature to form a gel-like product; the gel-like product is dried to obtain a precursor dry gel; then, after grinding and high-temperature annealing, M is obtained. x V₂O₅ material. The M x When V2O5 is used as a cathode material for lithium-ion secondary batteries, it exhibits excellent reversible capacity and cycle stability, and eliminates the problems of voltage drop and poor cycle stability of traditional V2O5 during discharge.

The invention provides a preparation method of a lithium ion battery negative electrode material. The method comprises the following steps: preparing an MXene material and CoNi-MOF; and synthesizing the MXene material and the CoNi-MOF into the negative electrode material of the lithium ion battery. The obtained lithium ion battery negative electrode material can be used as a lithium ion battery negative electrode material, the cycling stability of the battery is improved, and the cycling life of the battery is prolonged; when the material is used as a lithium ion battery negative electrode material, the lithium ion transmission path is shortened, and the material conductivity is improved; the prepared lithium ion battery has the advantages of high stability, long cycle life, high rate performance, simple preparation process, cheap and easily available raw materials, low cost, environmental friendliness and the like, and can effectively meet the actual application requirements of the high-energy-density lithium ion battery.

The present application relates to the technical field of energy storage materials, and in particular to a metal electrode with a rare earth alloy protective layer, and a preparation method and application thereof; the metal electrode comprises a metal electrode material and a rare earth alloy protective layer wrapped on the surface of the metal electrode material, wherein the thickness of the rare earth alloy protective layer is 5nm to 10μm; the method comprises: polishing the metal electrode material and the rare earth metal respectively; under preset temperature and preset pressure conditions, physically contacting the polished metal electrode material and the rare earth metal to realize in-situ generation of a rare earth alloy protective layer on the surface of the metal electrode to obtain a metal electrode; by covering the surface of the metal electrode with a rare earth alloy protective layer and limiting the thickness of the rare earth total protective layer, the purpose of improving the rate performance of the metal electrode while solving the problem of dendrite growth of the metal electrode is achieved.

A nitrogen-sulfur dual-doped and zinc-loaded ultra-thin carbon-walled carbon sphere and its preparation method and application, using zinc acetate dihydrate, thiourea, ethylenediamine, deionized water, and dimethylimidazole as raw materials, through the steps of hydrothermal synthesis of wurtzite zinc sulfide nanosphere precursor, carbonization and etching, to obtain radial carbon spheres stacked by fully closed mesopores. The internal mesopores of the carbon sphere are dense and connected, and the carbon wall is ultra-thin, only at the atomic level. The method provided by the present invention has a reference value for the regulation of zinc sulfide nanostructures, and when the ultra-thin carbon-walled carbon spheres synthesized based on this are used as negative electrode materials for sodium metal batteries, the ultra-thin carbon wall is conducive to the rapid penetration and transmission of sodium, and can achieve nano-encapsulation of sodium metal, thereby effectively limiting the deposition of sodium metal and inhibiting the generation of sodium dendrites, so that the metal battery has good electrochemical cycle performance.