10 results about "Electrochemical intercalation" patented technology

The invention belongs to the technical field of two-dimensional material preparation, and particularly relates to a preparation method of a Zr2N2X two-dimensional material. The preparation method comprises the following steps: firstly, by taking layered ZrNCl as a working electrode, applying constant current into an electrolyte containing organic ammonium salt, and carrying out electrochemical intercalation reaction to prepare an intercalated ZrNCl two-dimensional nanosheet; and mixing the ZrNCl subjected to electrochemical intercalation treatment with anhydrous Na2X (X = S, Se or Te), carrying out sealed reaction in a protective atmosphere, and carrying out solid-phase topological chemical conversion to generate the Zr2N2X two-dimensional material. Through the synergistic effect of electrochemical intercalation pretreatment and topological chemical conversion, the harsh degree of reaction conditions is reduced, meanwhile, the product quality and the process controllability are comprehensively improved, and a solid foundation is laid for industrial application of the two-dimensional semiconductor material.

A membrane-stacked electrolytic bath for lithium extraction from salt lakes by electrochemical intercalation / deintercalation includes a positioning supporting plate as well as a first compressing plate, a first rubber gasket, at least one electrochemical intercalation / deintercalation unit, a second rubber gasket, and a second compressing plate which are sequentially arranged in an overlapped manner; a compressing apparatus for abutting against the second compressing plate is arranged on one side of the second compressing plate to enable peripheral edges of the first compressing plate, the first rubber gasket, the electrochemical intercalation / deintercalation unit, the second rubber gasket, and the second compressing plate to be sealed; the first compressing plate is provided with water outlet pipes communicated with the electrochemical intercalation / deintercalation unit; and the second compressing plate is provided with water inlet pipes communicated with the electrochemical intercalation / deintercalation unit.

Methods for synthesizing layered lithium transition metal oxides from layered sodium transition metal oxides are provided. Also provided are electrodes for lithium-ion batteries that include the layered lithium transition metal oxides. Similarly, methods for the synthesis of layered sodium transition metal oxides from layered lithium transition metal oxides and electrodes for sodium-ion batteries that include the layered sodium transition metal oxides are provided. The methods couple electrochemical intercalation of alkali ions (Li+ or Na+) with ion-exchange to overcome the kinetic limitation of ion-exchange in the layered alkali transition metal oxides at low vacancy concentrations.

The present disclosure provides methods of producing isolated graphene sheets from graphite. Isolated graphene sheets produced by said methods, as well as articles and devices containing said isolated graphene sheets, are also provided. Electrochemical intercalation reactors for performing said methods are also provided.

This invention discloses a method for the electrochemical preparation of amorphous hydroxyferric phosphate electrode materials. The method uses ferric phosphate as a raw material to prepare the working electrode. Then, in an aqueous three-electrode system, an electrochemical method is used to induce periodic intercalation and deintercalation of metal ions to drive the collapse and rearrangement of the ferric phosphate lattice. Simultaneously, the hydroxyl groups in the aqueous electrolyte replace the phosphate groups in the ferric phosphate under the drive of the electrochemical intercalation and deintercalation reaction, thereby achieving the preparation of the amorphous hydroxyferric phosphate electrode material. This invention uses an electrochemical method for in-situ conversion to prepare amorphous hydroxyferric phosphate, eliminating the need for high-temperature, high-pressure hydrothermal reactions. The process is simple, requires minimal equipment, and the controllable synthesis of amorphous hydroxyferric phosphate can be achieved by adjusting the electrochemical parameters.

The application relates to the technical field of graphene, in particular to a graphene material and a preparation method and a preparation device thereof, the preparation method comprises the following steps: preparing an electrolysis system, including an anode, a cathode and an electrolyte, a first extension direction of the anode intersects with a second extension direction of the cathode; graphite is used as the anode to perform an electrolysis reaction, and the graphite is driven to move along the first extension direction to adjust the distance between the anode and the cathode; as the distance between the anode and the cathode decreases, the current density on the surface of the graphite gradually increases; the graphite is first subjected to electrochemical intercalation and then subjected to electrolytic exfoliation to obtain a graphene dispersion liquid; the graphene dispersion liquid is subjected to purification treatment to obtain graphene. In the preparation method, the electrochemical intercalation and the electrolytic exfoliation reaction on the graphite are performed in sequence, the prepared graphene material has a high few-layer (carbon layer number is less than or equal to 5) rate, and the types and contents of oxygen-containing functional groups can be controlled.

A method for preparing graphene by formic acid electrochemical intercalation and ultrasonic exfoliation belongs to the field of graphene preparation technology. The method includes the following steps: using graphite material as the working electrode, immersing it in a high-concentration formic acid aqueous solution as the electrolyte and intercalating agent, applying a constant voltage to carry out an electrochemical intercalation reaction, obtaining an expanded graphite intercalation precursor; washing and drying the precursor, dispersing it in a liquid medium, and performing ultrasonic exfoliation treatment to obtain a graphene dispersion; finally, obtaining the graphene material through solid-liquid separation and drying. This invention uses formic acid as the intercalation medium, avoiding the use of traditional strong acids and oxidants, significantly improving the cleanliness of the process. The combination of mild electrochemical intercalation conditions and subsequent ultrasonic treatment achieves efficient exfoliation of graphene and high fidelity of the lattice structure. The prepared graphene material has low defect density and excellent structural integrity and intrinsic properties. This invention has a simple process flow, mild operating conditions, and is environmentally friendly, suitable for the large-scale preparation of high-quality graphene.

Methods for synthesizing layered lithium transition metal oxides from layered sodium transition metal oxides are provided. Also provided are electrodes for lithium-ion batteries that include the layered lithium transition metal oxides. Similarly, methods for the synthesis of layered sodium transition metal oxides from layered lithium transition metal oxides and electrodes for sodium-ion batteries that include the layered sodium transition metal oxides are provided. The methods couple electrochemical intercalation of alkali ions (Li+ or Na+) with ion-exchange to overcome the kinetic limitation of ion-exchange in the layered alkali transition metal oxides at low vacancy concentrations.

The invention relates to the field of preparation of expandable graphite, in particular to a low-energy-consumption green expandable graphite processing method which comprises the following steps: firstly, carrying out microwave irradiation treatment on natural flake graphite to generate thermal stress cracks; and then the treated graphite serves as an anode and is placed in a composite electrolyte for constant-voltage electrochemical intercalation treatment. The electrifying duration and the initial voltage are adjusted in real time by detecting the settling velocity and the interlayer spacing of the intercalated graphite. Then, the intercalated graphite reaching the standard is placed in an organic solvent to be subjected to solvent replacement and auxiliary ultrasonic treatment, wormlike precursor graphite is obtained, and the preheating power of microwave expansion equipment is adjusted according to the turbidity of the replaced solution; and finally, determining the expansion duration by detecting the specific surface area of the precursor graphite. According to the method, the problem that in the prior art, the product quality is unstable due to the fact that the low-energy-consumption green expandable graphite electrolyte is prone to being excessively oxidized is solved through the process parameter adjusting procedure for detecting the expandable graphite.

The invention discloses a graphene composite lubricating additive and a preparation method thereof.The preparation method comprises the steps that a graphite rod serves as an anode, molybdenum disulfide serves as a cathode, and electrochemical intercalation is conducted in a fluorine-containing electrolyte solution; the mixture obtained through electrolysis is subjected to high-pressure homogenization treatment, and stripping and superfine grinding are achieved; and after washing and freeze-drying, calcining in an inert atmosphere to finally obtain the product. The preparation of nano graphene and molybdenum disulfide, fluorine functional group surface modification and composite assembly are realized in one step through a synergistic process of electrochemical intercalation, high-pressure homogenization and calcination; the method is simple in process, green, environment-friendly and pollution-free; in the prepared composite lubricating additive, the molybdenum disulfide nanosheets are loaded on the surface of the fluorine-functionalized graphene, the molybdenum disulfide nanosheets and the fluorine-functionalized graphene have a synergistic effect, and the obtained additive has excellent friction performance and high temperature resistance and is suitable for lubrication under severe working conditions such as high speed, heavy load and high temperature.