79 results about "Metal dissolution" patented technology

The invention provides a preparation method of a nickel-based composite oxygen evolution anode for alkalescent electrolyte. According to the invention, nickel-based alloy is used as substrates, two same substrates are respectively used as a working electrode and an auxiliary electrode, two-electrode system electrochemical oxidation reduction treatment at room temperature is carried out in a mixed solution of phosphate, carbonate and chloride, and two reconstructed nickel-based composite oxygen evolution electrodes are obtained at the same time. In the electrochemical oxidation process, nickel ions and other metal (Fe, Co, Cr and Mn) ions are dissolved out from the nickel-based alloy under the etching assistance of chloride ions; in the electrochemical reduction process, water on the electrode is reduced to form hydroxyl. Under continuous oxidation reduction, substance reconstruction is carried out to generate a composite catalyst layer of phosphate, carbonate and hydroxide of nickel and other metals, so that not only can the oxygen evolution activity be improved, but also metal dissolution and corrosion passivation when the catalyst is used in a weakly alkaline solution can be inhibited, and the durability of the electrode is greatly improved.

The invention relates to the technical field of electro-catalysis and hydrogen energy, in particular to a modified LDH-based catalyst and a preparation method and application thereof. The preparation method comprises the following steps: mixing trimesic acid, water, an organic solvent, a nickel salt, a cobalt salt and an iron salt, carrying out electro-deposition, washing and drying to obtain a NiFeCo-LDH (TA) catalyst; the preparation method comprises the following steps: soaking a NiFeCo-LDH (TA) catalyst in a silver salt solution, washing and drying to obtain the modified LDH-based catalyst. The modified LDH-based catalyst provided by the invention can effectively resist chloride ion corrosion and inhibit dissolution of active metals in layered double hydroxides (LDH) under high current density in seawater, can reach industrial grade current density under relatively low overpotential, and can stably run for more than 1000 hours.

The invention relates to a water treatment and membrane separation technology, and provides an integrated catalytic separation membrane, a preparation method thereof, and a water treatment method and system. According to the membrane, polyvinylidene fluoride is used as a continuous phase to form a porous matrix, and cerium dioxide is embedded and fixed in a mode of uniform dispersion in a membrane body in a phase inversion membrane forming process; in the presence of illumination and peroxysulfate, active species are generated through in-situ activation on a membrane-water interface, and membrane separation is completed synchronously. The water treatment method comprises the following steps: adding peroxymonosulfate or peroxydisulfate into a water body to be treated, and filtering through the membrane under illumination; the photothermal effect generated by organic matter degradation intermediates in operation inhibits membrane pollution and maintains flux. According to the invention, short-range coupling of active sites and mass transfer channels is realized, the medicament and energy utilization rate is improved, the coating stripping and metal dissolution risk is reduced, and the method is suitable for drinking water pretreatment, reclaimed water deep treatment and treatment of water containing natural organic matters / humic acid.

The invention discloses a tetrathiomolybdate intercalated ternary iron-magnesium-zinc layered double hydroxide catalyst, a preparation method thereof and an application of the tetrathiomolybdate intercalated ternary iron-magnesium-zinc layered double hydroxide catalyst in degrading azo dyes by activating peroxymonosulfate. According to the method, a carbonate intercalated ternary LDH precursor is synthesized through a hydrothermal reaction, interlayer anions are replaced with nitrate and tetrathiomolybdate through ion exchange, and the target catalyst is obtained. In the catalyst, a unique Fe-Mg-Zn ternary metal laminate and a MoS < 2-> intercalation structure cooperatively construct a multi-active center, and MoS < 2-> is used as an electron donor to promote cyclic regeneration of Fe < 3 + > / Fe < 2 + >. The catalyst keeps ultrahigh activity in a wide range of pH (potential of hydrogen) of 3-9, can completely degrade 10 mg / L of acid orange 7 within 5 minutes, and is stable in structure and low in metal dissolution risk. The problems of low activity, slow Fe < 3 + > reduction, metal ion dissolution and the like under neutral and alkaline conditions in an advanced oxidation technology based on peroxymonosulfate are solved, and the method has important application value in the field of printing and dyeing wastewater treatment.

The invention provides a NiMoO4-coated NiSe2-PA core-shell nanowire electrocatalyst as well as a preparation method and application thereof, and belongs to the technical field of electrocatalytic materials. The preparation method comprises the following steps: dissolving a Mo source, a Ni source and urea in water, and then mixing with a Ni matrix for hydrothermal reaction to obtain a NiMoO4 precursor; taking the NiMoO4 precursor and selenium powder as raw materials, and preparing NiSe2-coated NiMoO4 by adopting a chemical vapor deposition method; the NiSe2 (at) NiMoO4 is subjected to a self-assembly reaction in a phytic acid solution, and the NiMoO4 (at) NiSe2-PA core-shell nanowire electrocatalyst is obtained. According to the electrocatalyst, the industrial-grade current density and the high-stability alkaline seawater OER performance are achieved, the problem of metal dissolution in the selenide electrooxidation process is solved, and a simple and effective strategy is provided for reasonably designing the high-activity and corrosion-resistant industrial-grade seawater electrolysis catalyst.

The invention belongs to the technical field of inorganic nano materials and electro-catalysis, and particularly relates to a cobalt-based spinel oxide nano material as well as a preparation method and application thereof. The cobalt-based spinel oxide nano material comprises a conductive substrate and cobalt-based spinel oxide grown on the surface of the conductive substrate, the molecular formula of the cobalt-based spinel oxide is MxCo1-xO4, and M is transition metal or P-region metal and is selected from one or more of titanium, vanadium, chromium, manganese, iron, nickel, aluminum, cerium and neodymium. Multiple metal elements are doped into a cobaltosic oxide lattice, and the intrinsic structure of spinel is not changed by metal doping. Multiple metal elements are highly uniformly dispersed in the material, so that active sites are comprehensively regulated and controlled, the material shows excellent thermodynamic and chemical stability under harsh conditions of high temperature, large current, concentrated alkali and the like, is suitable for various electrolysis modes, has no metal dissolution risk in long-term operation, can effectively avoid the problems of membrane poisoning and membrane degradation, and has good application prospects. Wide application prospects are shown.

The invention discloses a fuel cell dry membrane electrode and a preparation method thereof, a catalyst and an ionomer are mixed in an aqueous solution, in the directly used catalyst, platinum black particles and a carbon carrier are anchored through a surface functional group, platinum nanoparticles are good in dispersity, and in the aqueous solution, the platinum black particles and the carbon carrier are uniformly dispersed. The negative-SO3H group from the ionomer particles can attract the positively-charged Pt particles, so that the ionomer can uniformly cover the surfaces of the Pt particles, an ionomer / Pt particle interface is spontaneously formed, the ionomer can be uniformly distributed on metal active sites, on one hand, the transfer of protons to the active sites can be accelerated, the reaction kinetics can be improved, and on the other hand, the reaction efficiency can be improved; on the other hand, metal dissolution or poisoning is reduced, and membrane electrode performance and service life are improved. The use of toxic and expensive organic solvents is avoided, a more environment-friendly and lower-cost dry preparation process is adopted, proton membrane swelling in the preparation process is avoided, and the proton conductivity is improved.

The invention relates to the technical field of wastewater treatment, in particular to an iron-based nano-enzyme coupled photocatalytic system and application thereof in organic wastewater degradation, and the iron-based nano-enzyme coupled photocatalytic system comprises the following components in percentage by weight: 10-20% of iron-based nano-enzyme, 15-25% of a modified photocatalyst, 25-35% of a porous carrier, 3-8% of an electron mediator, 1-3% of a pH regulator and 0.5-2% of a rare earth element dopant; the iron-based nano-enzyme is nitrogen-doped iron-copper-cobalt trimetal nano-enzyme, the molar ratio of Fe to Cu to Co is (6: 1: 1)-(8: 1: 1), the doping amount of N is 3-6at%, the particle size is 20-50nm, and the peroxidase activity is 120-150U / mg; the modified photocatalyst is graphene quantum dot-carbon dot co-modified titanium dioxide, the total loading capacity is 2-5 wt%, and the forbidden bandwidth is 2.8-3.0 eV; the porous carrier is a mesoporous silica-carbon nanotube-montmorillonite composite material. According to the invention, the synergistic degradation effect is excellent, refractory pollutants can be decomposed, and no toxic intermediates exist; the catalyst is suitable for high-salt and high-turbidity wastewater with different acidity and alkalinity, is good in stability, can be recycled, and is less in metal dissolution; the energy consumption is low, the operation is simple and convenient, the treated wastewater reaches the standard and can be recycled, and the environmental and economic benefits are remarkable.

The application discloses a method for recycling valuable metals in black powder in waste lithium batteries based on a Na2EDTA-malic acid mixed system, which comprises the following steps: 1) discharging, disassembling, crushing and screening the waste lithium batteries to obtain the black powder; 2) dispersing the black powder in a primary leaching liquid, adjusting the pH value of the primary leaching liquid to 3.0-4.5, and performing leaching in a water bath under stirring conditions, wherein the water bath temperature is controlled to be 50-90 DEG C, and the reaction is performed for 1-4 h, so that the metals in the black powder are dissolved into the liquid phase to form leaching slurry; and 3) performing liquid-solid separation on the leaching slurry obtained in the step 2) to obtain a leaching liquid containing Li, Ni, Co and Mn and leaching residue. The application has small corrosion, is green and environment-friendly, has high leaching efficiency, and is suitable for large-scale application.

The invention discloses an electrolyte of a ternary lithium ion battery, a preparation method of the electrolyte and the ternary lithium ion battery. The ternary lithium ion battery comprises an organic solvent system, a lithium salt system and an additive system, the organic solvent system is composed of at least one cyclic carbonate and at least one chain carbonate; the additive system comprises a cyclic compound, and the cyclic compound has the following structural formula; wherein X is any one of P, B and P = O; y is a C1-C6 carbon chain group containing an alkylene group, a carbonyl group, a sulfinyl group, a sulfonyl group or a fluoroalkylene group; the flame-retardant and anti-overcharge fabric has flame-retardant and anti-overcharge And moreover, by regulating and controlling the composition of the SEI film, the growth of lithium dendrites can be inhibited, the dissolution of transition metal can be reduced, the stability of the ternary lithium ion positive electrode material is improved, and the cycle life of the ternary lithium ion battery is prolonged.

Disclosed is a metal element recovery method which comprises: a step (1) for obtaining an acidic first solution by dissolving a metal in a crushed product of a lithium ion battery in an acidic aqueous solution; a step (2) for changing divalent iron ions in the first solution to trivalent iron ions; a step (3) for obtaining a second solution and a first precipitate that contains an iron compound or the like by adjusting the pH of the first solution to fall within the range of 3.0 to 5.0; a step (4) for obtaining a third solution and a second precipitate that contains copper sulfide by adding a sulfurizing agent to the second solution and adjusting the pH of the second solution to fall within the range of 4.0 to 5.0; a step (5) for obtaining a fourth solution and a third precipitate that contains nickel hydroxide or the like by adjusting the pH of the third solution to fall within the range of 7.0 to 8.5; and a step (6) for obtaining a fifth solution and a fourth precipitate that contains a lithium compound by concentrating the fourth solution while injecting a carbon dioxide gas thereinto.

The invention relates to the technical field of water treatment, and provides a composite material for water treatment, which comprises: a porous base material; the catalyst layer is formed on the surface of the porous base material; the biological affinity layer is formed on the surface of the catalyst layer; the enhancement layer is formed on the surface of the biological affinity layer, and the enhancement layer is graphene quantum dots. The invention further provides a preparation method of the composite material in the technical scheme and water treatment equipment. According to the composite material provided by the invention, through'metal oxide-biological affinity layer-graphene quantum dot 'ternary synergy, deep coupling of ozone oxidation and biodegradation is realized, the ozone removal rate is increased, the microbial biofilm formation rate is increased, the biofilm formation period is shortened to 3-5 days, and the biofilm density is increased by 30%; and the COD (Chemical Oxygen Demand) removal rate is relatively high. Moreover, the composite material provided by the invention is relatively stable, the metal dissolution rate in a high-humidity environment is less than or equal to 1%, and the service life is prolonged to more than 3 years.

The application relates to the technical field of electrolytic polishing, and discloses a stainless steel cavity surface treatment device with an electrolytic polishing function, which comprises an electrolytic machine and an electrolytic tank arranged on the electrolytic machine, and linear driving mechanisms are arranged on the two sides of the electrolytic machine and extend along the height direction of the electrolytic machine. The stainless steel cavity surface treatment device with the electrolytic polishing function is provided with a pumping pipe at the top end of a limiting pipe and is equipped with a pump body, so that the electrolyte in the stainless steel container can be pumped and circulated, the flowability and the updating speed of the electrolyte on the inner wall of the container are effectively improved, the bubble adhesion is reduced, the problem of uneven metal dissolution caused by slow electrolyte updating is avoided, the generation of surface defects such as pitting, mottling and scratches is reduced, the uniformity of the surface color of the workpiece is ensured, the quality of the electrolytic polishing is improved, and meanwhile, the electrolyte is filtered after being pumped through a return pipe and is then delivered back to the electrolytic tank, so that the electrolyte can be recycled.

The structure is simplified, and the molten metal flows more smoothly, allowing for efficient dissolution and heating. [Solution] The furnace body 10 has heating chambers 12 and 13 that communicate with an input port 11 for non-ferrous metal materials, and a tapping chamber 14 that can receive a portion of the molten metal heated to a predetermined temperature in the heating chambers 12 and 13 and from which the molten metal can be removed, and a rotating blade 20 for circulation that is provided in the center of the heating chambers 12 and 13 to circulate the molten metal, and a plurality of electric heaters 30 and 40 provided in the heating chambers 12 and 13 to raise the molten metal to a predetermined temperature.

The invention relates to a diamond electrolytic purification method, and relates to the technical field of diamond purification, the diamond electrolytic purification method comprises a raw material screening step, a pretreatment step, an electrolytic purification step and a separation and purification step, the temperature of the electrolyte is 40-50 DEG C, the flow velocity of the electrolyte is 0.5-1.5 m / s, the diamond particles are washed, energized electrolysis is carried out for 8-12 h, the current density is 20-30 mA / cm, ultrasonic treatment is carried out while electrolysis is carried out, the ultrasonic frequency is 10-20 kHz, and mixed slurry is obtained. According to the diamond obtained through the electrolytic purification method, efficient metal dissolution can be achieved, the metal dissolution efficiency is improved, the diamond structure is protected, and the diamond purity is improved.

The application discloses a lithium ion battery and a preparation method thereof. The positive electrode material contains boron elements, and the distribution amount of the element B meets the following characteristics: the content of boron in the positive electrode material is less than or equal to 20% of the total mass of boron elements, the content of boron elements in the negative electrode is less than or equal to 20% of the total mass of boron elements, and the content of B elements in the electrolyte is greater than or equal to 60% of the total mass of boron elements. The method improves the accumulation orientation of the transition metal layer, improves the charge density distribution of oxygen elements, cooperatively improves the stability of the negative electrode SEI film, reduces the electrolyte consumption and metal dissolution, and improves the mechanical compression resistance.

The invention discloses a Co-Cu / rGO-Ti electrode and a preparation method and application thereof, and belongs to the technical field of sewage electrochemical treatment.The preparation method comprises the following steps that a Ti net is pretreated, and the pretreated Ti net is obtained; gO is dispersed in deionized water, and a GO dispersion liquid is obtained; co salt and Cu salt are mixed in deionized water, and a Co-Cu mixed salt solution is obtained; immersing the pretreated Ti net into the GO dispersion liquid, taking out the Ti net, and drying the Ti net to obtain dried GO-Ti; dipping in a Co-Cu mixed salt solution at a constant temperature, taking out and drying to obtain a dipped and dried electrode; and putting the GO into a muffle furnace for calcination, reducing the GO into rGO by adopting a high-temperature calcination method, and decomposing the Co-Cu salt into metal oxide nanoparticles, thereby finally obtaining the Co-Cu / rGO-Ti electrode. According to the invention, agglomeration of Co-Cu particles can be avoided, uniform distribution and long-term stability of active sites are ensured, cyclic utilization of the electrode is ensured, dissolution of Co-Cu metal can be reduced, and secondary pollution is avoided.

A copper electrolyte comprising (a) a water-soluble copper salt; (b) a complexing agent; (c) a leveling agent; (d) optionally, a polar solvent; (e) optionally, a pH adjusting agent; and (f) the balance of water. The copper electrolyte has a pH in the range of from about 8 to about 11, preferably from about 8.2 to about 9.5. The copper electrolyte can be used to deposit ultra-thin copper layers on conductive substrates that are free of pinholes and other defects and inhibit metal dissolution.

A composite lithium replenisher, its preparation method, and a secondary battery are disclosed. The composite lithium replenisher includes an active lithium unit and a functional unit. The active lithium unit contains a complexing group; the functional unit contains a self-healing group, which is connected to the active lithium unit. The composite lithium replenisher can self-repair through the self-healing group. This composite lithium replenisher can form a dense SEI film on the positive electrode surface, thereby inhibiting the problem of metal dissolution catalysis and reducing the electrolyte oxidation decomposition rate. The self-healing group can undergo reversible breakage-recombination during charge-discharge cycling, regulating and repairing the damaged SEI film after cycling, making the SEI film more stable, and inhibiting lithium dendrite growth and uncontrolled lithium deposition caused by local polarization. The synergistic effect of both improves the problem of metal dissolution catalysis during the delithiation process of the lithium replenisher, which further exacerbates the SEI film rupture.

This invention discloses a highly efficient and low-cost method for preparing g-C3N4-supported Fe and Mn bimetallic catalysts, belonging to the field of catalyst technology. This invention uses manganese ferrite as the bimetallic source, combined with a one-step calcination method using melamine, to simultaneously achieve the synthesis of g-C3N4 and the loading of Fe and Mn. During calcination, manganese ferrite decomposes into FeO. x and MnO x Nanoparticles form strong coordination bonds with the nitrogen sites of g-C3N4, enabling atomic-level dispersion of metals and inhibiting metal ion migration. Through the bimetallic synergistic effect of Fe and Mn, the redox capacity of the catalyst can be significantly improved. Manganese ferrite, through its unique thermal decomposition characteristics, bimetallic synergistic effect, and strong chemical bond with g-C3N4, achieves efficient exposure of active sites, significant improvement of redox capacity, and effective inhibition of metal dissolution. It also has the advantages of high efficiency, low cost, and low risk of secondary pollution.

The invention discloses a method for extracting metal salts and metals from polymetallic ores or polymetallic materials. The method comprises the following steps: 1) raw material pretreatment: crushing and grinding raw materials into particles; 2) full-wet dissolution extraction: leaching corresponding acid, a corresponding oxidant, a corresponding catalyst and water from the product obtained in the step 1) by using the required metal, stirring and heating to boiling until the required metal in the raw materials is dissolved in the liquid; (3) carrying out solid-liquid separation on the leached product in the previous step, and carrying out mother liquor cooling on the mother liquor subjected to the solid-liquid separation to separate metal elements which can be subjected to alum formation and metal elements which cannot be subjected to alum formation; and (4) sequentially separating out salts of metal elements capable of forming vitriol from the metals capable of forming vitriol according to a sequence from strong vitriol forming capability to weak vitriol forming capability of the metals. The problems that in the prior art, cost is high, and pollution to the environment is large are solved.

[Problem] The purpose of the present disclosure is to provide a cleaning agent composition that has an aroma tone similar to that of a floral fragrance compound containing linalool and ethyl maltol, and that can suppress discoloration and metal dissolution occurring over time. [Solution] A cleaning agent composition according to the present disclosure is characterized by containing a floral fragrance compound containing linalool and 2,3-dihydrofarnesal, and a quaternary ammonium salt. [Selected figure] None

To provide a detergent composition that exhibits a fragrance similar to that of a floral blended fragrance containing linalool and ethyl maltol, while suppressing time-dependent discoloration and metal dissolution.SOLUTION: The detergent composition of the present disclosure comprises a floral blended fragrance containing linalool and 2,3-dihydrofarnesal, and a quaternary ammonium salt.SELECTED DRAWING: None

The invention relates to the technical field of analysis and detection, and discloses a rapid detection method for low-content silicon in magnesium and magnesium alloy. According to the method, a hydrogen peroxide solution with the concentration of 1-1.2 g / mL and hydrochloric acid with the concentration of 0.54-0.6 g / mL are used for dissolving a silicon-containing magnesium source. The hydrogen peroxide solution enhances oxidability and promotes metal dissolution, the dissolution speed of the sample can be effectively increased, a large amount of salt and new silicon element cannot be introduced into the solution to be detected, the pretreatment of the sample is simple and rapid, and the detection result is accurate; meanwhile, hydrogen peroxide is firstly added and then hydrochloric acid is added, so that the generation of silane is effectively inhibited, and the reaction with impurity ions in a magnesium source can be realized to prevent interference; the hydrogen peroxide is heated, boiled and decomposed at low temperature lower than 280 DEG C, so that the hydrogen peroxide is effectively removed, silicon compounds in the solution are prevented from being evaporated and polymerized, the acidity of the solutions is kept basically consistent, and the detection accuracy is further ensured.

The present application relates to a kind of methods for electrolytic purification of diamond, it relates to diamond purification technical field, the method for electrolytic purification of diamond includes raw material screening step, pretreatment step, electrolytic purification step, separation and purification step, wherein, electrolytic purification step includes the pretreated diamond particles are placed on anode, electrolyte temperature is 40-50 ℃, electrolyte flow rate is at 0.5-1.5 m / s speed to flush the diamond particles, and power electrolysis 8-12 h, current density is 20-30 mA / cm², while electrolysis is carried out ultrasonic treatment, and the ultrasonic frequency is 10-20 kHz, obtain mixed slurry. The diamond obtained by the electrolytic purification method of the present application can realize efficient dissolution of metal, improve metal dissolution efficiency, protect diamond structure and improve diamond purity.

A process of recovering at least one dissolved metal from metals laden water is provided which includes introducing oxygen nanobubbles into the metals laden water, wherein each nanobubble is a size in a range of from 1 nanometer to 900 nanometers; oxidizing the at least one dissolved metal with the oxygen nanobubbles; and precipitating out oxidized metal from the metals laden water for recovering a treated liquid stream and metal particulate. The metals laden water may be for example acid-mine drainage, process streams and wastewaters generated from mining and metals refining operations, process streams and wastewaters generated from metals recycling streams and any other process stream or wastewater generated by an industrial or naturally-occurring process in which metals are dissolved into water.

The application discloses a method for electrochemically assisted green leaching of retired lithium ion batteries, and belongs to the technical field of key metal recycling of retired lithium batteries and retired battery recycling, and specifically comprises the following steps: disassembling a retired ternary lithium battery, taking out a positive electrode material, cleaning, drying and grinding the positive electrode material, and placing the positive electrode material in a reaction container together with a weak acid solution to form a leaching system; installing an inert electrode in the reaction container, connecting an external direct current power supply, gradually adjusting the voltage according to the potential requirement of metal ion dissolution, and making nickel ions, cobalt ions and manganese ions be leached respectively to obtain a multi-metallic noble liquid; adding a precipitant to the obtained solution to perform precipitation, generating lithium carbonate precipitate, and recycling the lithium carbonate precipitate through filtration, washing and drying to obtain a high-purity lithium compound. The application not only reduces the use of strong acid and complex chemical reagents, significantly reduces the complexity of waste liquid treatment, and realizes efficient recycling of target metals through step-by-step control of the metal dissolution process.

The invention belongs to the technical field of secondary batteries, and particularly relates to a positive pole piece, a lithium ion secondary battery and electric equipment. According to the invention, a specific amount of soluble solid organic phosphonate is directly added into the positive electrode active layer, the soluble solid organic phosphonate can be dissolved in an electrolyte to complex metal ions (such as manganese ions and the like) dissolved out from the positive electrode side, the complexing capacity is high, the complexing stability constant is large, and the metal ions and the like are not easy to dissociate after being complexed; moreover, chemical stability is good, an obvious effect can be achieved by using a small amount of the material, metal dissolution dynamic balance on the positive electrode side is achieved, further dissolution of the metal is limited, and the cycle performance is improved; meanwhile, after the selected soluble solid organic phosphonic acid or salt thereof is dissolved in the electrolyte, the porosity of the positive pole piece can be increased, the wettability of the electrolyte on the positive pole piece is improved, the rate capability is improved, and the cycle performance and the rate capability are both considered.

The present invention provides a metal melting method for a manufacturing process of metal components having a desired shape, using metallic materials unaffected by oxygen and the constituent materials of the crucible. [Solution] In the manufacturing of a metal member, the first step is to prepare a crucible having an opening formed on its bottom surface to control the cross-sectional shape of the metal member to be manufactured; the second step is to bring the bottom surface of the crucible having the opening below the freezing point of the metal material constituting the metal member, thereby creating a melt-containing state in which the molten metal material is contained within the crucible; and the third step is to draw out the molten metal material from the opening in the melt-containing state so that a solid-liquid interface is formed inside the opening, thereby manufacturing a metal member whose cross-sectional shape is the shape of the opening. In this manufacturing method, the melt-containing state is achieved by using high-frequency induction heating to create the molten metal material, and the crucible is a double crucible or a crucible whose entire body is lined or coated with metal.

The invention relates to the technical field of lithium ion batteries, in particular to a positive electrode material and a preparation method thereof, a positive plate, a lithium ion battery and electric equipment. The positive electrode material comprises a spinel lithium nickel manganese oxide matrix material and a coherent coating layer, the coherent coating layer comprises a first coating material and / or a second coating material; the chemical formula of the first coating material is LiALO4, the chemical formula of the second coating material is LiZ0. 5L1. 5O4, A comprises Fe and / or Co, L comprises at least one of Mn, Zr, Ti and Si, and Z comprises at least one of Mg, Zn and Cu. The coherent coating layer has high stability under the high voltage of 5V, can resist erosion of acidic substances in an electrolyte, avoids side reaction with the electrolyte, protects the surface structure of the spinel lithium nickel manganese oxide matrix material, reduces metal dissolution, and improves the specific capacity and the cycle retention rate of the positive electrode material.