511 results about "Aluminum element" patented technology

The invention discloses a corrosion-resistant and anti-aging plastic packaging film and a preparation method thereof, and is used for solving the technical problem that the corrosion resistance and ultraviolet aging resistance of a packaging film in the prior art need to be further improved. The polypropylene composite material comprises the following raw materials in parts by weight: 60-80 parts of modified polypropylene resin, 1-2 parts of a compound nucleating agent, 10-15 parts of a modified filler, 1-2 parts of an antioxidant, 1-2 parts of an ultraviolet light absorber, 1-2 parts of a light stabilizer and 3-5 parts of a plasticizer, the tensile property of the material is improved through crystal form remolding, and the flame retardant property of the material is improved through synergistic cooperation of an internal phosphate structure, an aluminum element and thiocyanuric acid and siloxane chain segments in the material; and the ultraviolet light absorber cross-linked by the compound nucleating agent, the modified filler and the siloxane chain segment are synergistically matched, so that the ultraviolet aging resistance of the material is remarkably improved.

The invention relates to a magnetron sputtering system and a coating method thereof, the system comprises a pair of twin silicon target material and aluminum target material which are arranged in a coating chamber, the aluminum target material is located in the middle of a horizontal line where the twin silicon target material is located, the twin silicon target material is electrically connected with a medium-frequency power supply, and the aluminum target material is electrically connected with a direct-current power supply. According to the structural design, on one hand, the uniform deposition range can be expanded, the deposition difference of wide workpieces can be reduced, and the whole surface insulation consistency can be ensured, and on the other hand, the aluminum target realizes uniform doping of the aluminum element and stable control of the content, so that the toughness and binding force of the coating are improved, the influence on insulation is avoided, and the comprehensive performance of the non-conductive coating is remarkably improved.

The invention relates to the technical field of batteries, and discloses a battery, a battery pack and electric equipment, and the battery comprises a pole assembly arranged on a shell; the battery cell comprises a battery cell body and a tab part extending from the battery cell body, and the tab part is welded with the pole assembly to form a first welding printing area; wherein the tab part comprises an aluminum element, a manganese element and / or a silicon element, and the mass ratio of the manganese element and / or the silicon element is a%; a resistance test point is formed on the non-welding area of the tab part, the first welding printing area is located between the pole assembly and the resistance test point, and the resistance between the pole assembly and the resistance test point is b; the tab part comprises a plurality of tab layers which are stacked, and the thickness of each tab layer is c; a, b, and c satisfy 0.004 < = b * a / c < = 15. The lithium separation risk of the battery is reduced while the over-current capability between the pole component and the tab part is ensured and the voltage jump of the battery is avoided, so that the reliability of the battery is ensured.

The invention provides aluminum-doped hematite, a preparation method of the aluminum-doped hematite and application of the aluminum-doped hematite in catalyzing peroxides to degrade organic pollutants or remove pathogenic bacteria. The preparation method of the aluminum-doped hematite comprises the following steps: adding ferric iron salt and aluminum salt into deionized water, reacting, precipitating to separate out a product, washing, drying and grinding to obtain a precursor; calcining the precursor, and then washing and drying to obtain the aluminum-doped hematite. The preparation method is simple, cheap and easily available in raw materials, low in cost, green, safe and environment-friendly; the aluminum element is introduced into the hematite, so that the catalytic activity of the hematite is improved, and the catalytic condition is easy to realize; the aluminum-doped hematite disclosed by the invention has excellent capability of activating peroxide, so that the aluminum-doped hematite shows excellent performance in the aspects of removing environmental organic pollutants and sterilizing.

The invention belongs to the field of coal gangue resource utilization, and particularly discloses a method for separating and recovering silicon and aluminum elements from coal gangue. The coal gangue is used as a raw material, and efficient resource utilization of the coal gangue is realized through crushing and ball milling, high-temperature roasting activation and acid-base combined treatment. The coal gangue is subjected to high-temperature fluorination roasting by adopting an activating auxiliary agent fluorinating agent to form soluble fluosilicate (H2SiF6) and a fluorine-aluminum compound (AlF3), so that the subsequent silicon-aluminum separation is obviously promoted. The method comprises the following steps: desiliconizing through alkali treatment, leaching and converting silicon in the coal gangue into sodium silicate, and carrying out solid-liquid separation to obtain sodium silicate filtrate and aluminum-rich leaching residues; and then acid treatment is conducted on the aluminum-rich leaching residues, aluminum salt or aluminum hydroxide is prepared, and finally efficient separation of silicon and aluminum is achieved. According to the method, through high-temperature activation roasting, the normal-pressure alkaline leaching desiliconization effect is improved, the acid extraction aluminum efficiency is remarkably improved, the advantages of an acid method and an alkaline method are effectively combined, and the problems that coal gangue resources are difficult to utilize and the resource recovery rate is low are solved.

The invention discloses a recycling method of a positive plate of a waste lithium ion battery, and relates to the technical field of resource recycling of the waste lithium ion battery. The method comprises the following steps: (1) pretreatment of the waste lithium ion battery: discharging, disassembling and crushing the waste lithium ion battery to obtain positive plate scraps; (2) catalytic leaching of the positive plate chippings: preparing a leaching agent solution from acid, an iron-containing compound and a chlorine-containing compound, adding the positive plate chippings into the leaching agent solution for reaction, and filtering to obtain a leaching solution; (3) iron and aluminum in the leachate are separated, specifically, an alkali solution is added to increase the pH of the leachate to precipitate iron and aluminum, and precipitates containing iron and aluminum and a valuable metal solution are obtained through filtering separation; and (4) recovery of the catalyst: putting the iron-aluminum precipitate into an alkali solution, dissolving an aluminum element, and filtering to obtain an iron precipitate. The process flow is simple, no extra reducing agent needs to be added, and recovery of all metal elements in the positive plate is achieved.

The invention provides a high-temperature-resistant iron-chromium black pigment as well as a preparation method and application thereof, and belongs to the technical field of pigments. The preparation method comprises the following steps: preparing porous SiO2 / Al2O3 nanospheres, modifying the surfaces of the porous SiO2 / Al2O3 nanospheres by using tannic acid, depositing iron-containing and chromium-containing precipitates in situ, impregnating zirconium, calcining to obtain a precursor, and modifying the surfaces of the porous SiO2 / Al2O3 nanospheres by using polydopamine to obtain the high-temperature-resistant iron-chromium black pigment. The high-temperature-resistant iron-chromium black pigment prepared by the preparation method disclosed by the invention contains an aluminum element, so that the high-temperature-resistant, heat-resistant and flame-retardant properties of a prepared precursor are greatly improved, and the high-temperature-resistant iron-chromium black pigment contains silicon oxide, so that the temperature resistance and the wear resistance are obviously improved, and the high-temperature-resistant iron-chromium black pigment is relatively uniform in black, uniform in particle size, good in weather resistance and light resistance, good in dispersity and wide in application prospect.

The invention discloses a ternary positive electrode material, a preparation method thereof and an electrochemical device. The preparation method comprises the following steps: mixing a continuous ternary precursor, a lithium source and an aluminum source, and carrying out first sintering to obtain a first sintered product; the primary sintering product is subjected to secondary sintering and dispersion, a single-crystal base material is obtained, the base material comprises a plurality of primary particles, the average size of the primary particles ranges from 2 micrometers to 3 micrometers, and the median particle size Dv50 of the primary particles ranges from 3 micrometers to 5 micrometers; mixing the matrix material with an aqueous solution of lithium phosphate, and carrying out wet coating to obtain a coated product; and sintering the coated product for the third time, so that the lithium phosphate forms a coating layer on the surface of the matrix material, and the ternary positive electrode material is obtained. According to the invention, through two-parameter control of the average size and the median particle size of the matrix material and simultaneous aluminum element internal doping and lithium phosphate surface coating of the matrix material, the structural stability and the cycle performance of the ternary positive electrode material are improved and the service life of the ternary positive electrode material is prolonged through a synergistic effect.

The invention relates to the technical field of metal powder injection molding, in particular to an MIM titanium alloy binder and application of the MIM titanium alloy binder to preparation of high-plasticity TC4 parts. The MIM titanium alloy binder comprises polyformaldehyde, aluminum stearate, polyethylene, queen bee wax and high-density polyethylene. According to the MIM titanium alloy binder, polyformaldehyde serves as a main component, high-melting-point bee wax and aluminum stearate are introduced, the bee wax can improve the thermal stability of a lubricant, aluminum stearate can inhibit volatilization of Al element, the rheological property and sintering behavior of feeding are remarkably optimized, the number of titanium alloy feeding cycles and the density after sintering can be increased, and the O content can be reduced.

The invention discloses an in-situ synthesis Al2O3 reinforced low-density steel-based composite material and a preparation method of the in-situ synthesis Al2O3 reinforced low-density steel-based composite material. The in-situ synthesis Al2O3 reinforced low-density steel-based composite material comprises a steel matrix and an Al2O3 reinforced phase distributed in the steel matrix, the steel substrate is made of high-aluminum steel; the Al2O3 reinforced phase is generated by an in-situ reaction of an oxygen element in the metal oxide molten salt and an aluminum element in the high-aluminum steel melt in the smelting process, and the volume percent of the Al2O3 reinforced phase in the steel matrix is 10-20%. In the casting process, Al2O3 reinforced phase particles are generated in a steel matrix through in-situ reaction, good combination of the Al2O3 reinforced phase particles and the steel matrix is achieved, and the overall performance of the material is improved under the condition that the low density of the steel-based composite material is guaranteed.

The invention belongs to the technical field of wastewater treatment, and particularly relates to multi-element doped synergistically modified ferrihydrite as well as a preparation method and application thereof, and the ferrihydrite is doped with at least one rare earth element and at least one of an aluminum element and a silicon element; the doping amount of the rare earth elements in the ferrihydrite is 0.5-20wt%; the doping amount of the aluminum element in the ferrihydrite is 0-20wt%; the doping amount of the silicon element in the ferrihydrite is 0-20wt%. Compared with the prior art, the method solves the problems that in ferrihydrite single-element modification in the prior art, although stability is improved through Al / Si doping, element modification in the same period is limited in improvement of the adsorption capacity, and the specific recognition capacity on phosphate radicals cannot be improved; and the anti-interference performance of the rare earth doped in the complex water matrix still needs to be improved. According to the scheme, rare earth and Al / Si doping are combined, so that improvement of phosphorus adsorption stability, adsorption capacity, specific recognition capability and anti-interference performance of ferrihydrite is realized synergistically.

The invention provides a solid electrolyte and a preparation method thereof, a diaphragm, a battery and power-related equipment, and relates to the technical field of lithium batteries. The solid electrolyte is of a core-shell composite structure with LATP as a core and Mg-Sn alloy as a shell wrapping the outer surface of the core. According to the solid electrolyte with the core-shell structure, the LATP serves as the core, the Mg-Sn alloy serves as the shell, air stability is enhanced, Li2CO3 impurities are prevented from being generated, high ionic conductivity and a wide electrochemical window are kept, and stability and mechanical strength are improved. The corrosion resistance and tear resistance of the alloy enhance the safety of the battery, and the aluminum element in the LATP improves the strength of the alloy and optimizes the performance and charge-discharge efficiency of the battery.

The invention discloses a method for achieving titanium-aluminum alloy additive manufacturing through an electron beam spot melting process. The method comprises the steps that firstly, after a three-dimensional CAD model of a target product is established, layering slicing is conducted; 2, preheating and heat preservation of the substrate; 3, spreading powder and preheating a powder bed; 4, additive manufacturing process parameters are set, powder melting and solidification are carried out point by point, and a single-layer solid sheet layer is obtained; 5, carrying out secondary preheating treatment on the powder bed and descending the forming platform; and 6, repeating the process to obtain the titanium-aluminum alloy. A discrete point melting technology is adopted to replace a traditional line scanning continuous melting technology, point melting and solidification are carried out on a target area in a powder bed one by one, the size of a molten pool is reduced, the cooling speed of the molten pool is increased, the heat affected zone range of the edge of the molten pool is reduced, the influence time of the heat affected zone is shortened, and the uneven structure caused by aluminum element volatilization and phase change is avoided; and meanwhile, single-process printing of the titanium-aluminum alloy complex part is achieved, the difficulty and cost of the additive manufacturing process are reduced, and the method is suitable for the field of titanium-aluminum alloy additive manufacturing.

The invention relates to high-aluminum-content basic cobalt carbonate and a preparation method thereof. The method comprises the following steps: 1) preparing a mixed solution from cobalt salt and aluminum salt; (2) adding a small amount of ammonium bicarbonate solution into a reaction kettle, starting heating, adding the mixed solution into the reaction kettle while stirring, controlling the pH value, and reacting to obtain a seed crystal dispersion liquid; and (3) adding the mixed solution and an ammonium bicarbonate solution into the seed crystal dispersion liquid, controlling the pH value, continuously reacting under heating and stirring until the particle size of the basic cobalt carbonate reaches a set value, stopping the reaction, and carrying out filter pressing, washing and drying to obtain the basic cobalt carbonate with high aluminum doping amount. The aluminum doping in the basic cobalt carbonate provided by the invention is as high as 7767-8357ppm, and the aluminum element is uniformly distributed and does not segregate.

According to one aspect of the present invention, a method for preparing a zirconium-doped ternary positive electrode material is provided, comprising the following steps: S1. According to the stoichiometric ratio of each element in the zirconium-doped ternary positive electrode material, a first precursor is prepared by a first coprecipitation reaction using a soluble nickel salt, a soluble cobalt salt and a soluble salt containing the M element, wherein the first precursor contains nickel element, cobalt element and M element, wherein the M element includes at least one of manganese element and aluminum element; S2. A zirconium-containing compound is deposited on the surface of the first precursor by a second coprecipitation reaction to obtain a second precursor; S3. According to the stoichiometric ratio of each element in the zirconium-doped ternary positive electrode material, the second precursor is mixed with a lithium source to obtain a third precursor, and the third precursor is calcined by a high-temperature solid phase method to obtain the zirconium-doped ternary positive electrode material.

The invention discloses an improvement method of sludge soft soil layer shield muck, and belongs to the technical field of shield tunnel construction muck improvement. Metakaolin, blast furnace slag, lignosulfonate and nano silicon dioxide powder are mixed to prepare a mixed raw material, the mixed raw material is pumped into a muck bin, then an alkali-activated solution is pumped into the muck bin, and the mixed raw material is stirred to be uniform; and after mixing and stirring, adding anionic polyacrylamide powder and bentonite, and continuously stirring until a gel system is generated, thereby completing muck improvement. According to the invention, sodium hydroxide and sodium silicate are used as alkali-activated solutions to activate a gel system, blast furnace slag provides a large amount of silicon elements and aluminum elements, and metakaolin contains silicon, aluminum and calcium elements to improve the strength of the gel system; during use, the two raw materials are separated, so that the two raw materials are prevented from reacting in advance before reaching a muck bin to generate gel, and pipeline blockage is avoided; the anionic polyacrylamide and the bentonite are matched, so that the permeability is improved, the drainage of water is facilitated, and the occurrence of spewing is effectively prevented.

The invention discloses a micro-arc oxidation surface modified biomedical titanium alloy with good friction corrosion resistance and a preparation method of the micro-arc oxidation surface modified biomedical titanium alloy. The micro-arc oxidation surface modified biomedical titanium alloy comprises a titanium alloy base material and a micro-arc oxidation coating located on the surface of the titanium alloy base material. The micro-arc oxidation coating comprises a compact layer and a sparse layer which are sequentially connected with the titanium alloy base material. EDS element analysis shows that the micro-arc oxidation coating contains a sodium element, an oxygen element, an aluminum element, a phosphorus element, a potassium element, a titanium element and a niobium element. The preparation method comprises the following steps: preparing a micro-arc oxidation electrolyte, wherein the micro-arc oxidation electrolyte comprises sodium titanate, potassium hydroxide, sodium hexametaphosphate and niobium particles; the titanium alloy base material serves as an anode, a stainless steel sheet serves as a cathode, the micro-arc oxidation electrolyte is loaded into an electrolytic cell, then a micro-arc oxidation electrolytic reaction is conducted, and the micro-arc oxidation coating is generated on the surface of the titanium alloy base material.

The invention provides a laser welding method for a metal workpiece with an aluminum coating on the surface. The laser welding method comprises the following steps that (1) a first metal workpiece and a second metal workpiece which are used for welding and a laser beam used for laser welding are provided; the first metal workpiece and the second metal workpiece are respectively provided with a top surface and a bottom surface, and at least one workpiece surface is provided with an aluminum coating; the first metal workpiece and the second metal workpiece are in butt joint to form a to-be-welded assembly and a butt joint line; and (2) a laser beam advances in the direction of the butt joint line of the to-be-welded assembly so as to melt the butt joint position of the first metal workpiece and the second metal workpiece, and a welding seam is formed after cooling and solidification. According to the method, multiple laser beams are provided to act on laser welding of butt joint of the steel with the aluminum coating, so that the aluminum element is uniformly distributed in a welding seam, the influence of aluminum on a welding joint is weakened, the method is low in cost and simple to operate, and the laser welding joint with excellent performance can be obtained.

The invention provides a functional filler, a preparation method thereof, an inorganic thermal control coating and application, and belongs to the technical field of coatings. The preparation method of the functional filler comprises the following steps: by taking a zinc acetate aqueous solution as a raw material, adding indium nitrate and aluminum nitrate, stirring and dissolving, then sequentially adding a complexing agent and a stabilizer, heating in a water bath to form transparent gel, and finally sintering at high temperature. According to the preparation method, a sol-gel method and a high-temperature sintering process are adopted to dope an indium element and an aluminum element into zinc oxide to prepare indium-aluminum co-doped zinc oxide, and then the indium-aluminum co-doped zinc oxide is used as a functional filler to be added into inorganic silicate resin to prepare the inorganic thermal control coating. The aluminum element and the indium element can synergistically act to improve the temperature resistance of the coating, so that the inorganic silicate coating with protection and thermal control effects is obtained, can be used on the surface of a spacecraft and has good thermal control and temperature resistance effects.

The invention discloses a high-temperature-resistant composite coating and a preparation method thereof.According to the high-temperature-resistant composite coating, a first high-temperature-resistant coating is prepared on the surface of a base material through a plasma spraying method, and the first high-temperature-resistant coating is a composite coating composed of Al / Al2O3 with excellent high-temperature resistance; on the basis, a high-entropy alloy is introduced to serve as a second high-temperature-resistant coating, the high-temperature-resistant coating takes an aluminum element as a core element and can form good metallurgical bonding with the first high-temperature-resistant coating, and the second high-temperature-resistant coating is prepared through a laser cladding method, so that the bonding property with the first high-temperature-resistant coating is further enhanced. The high-entropy high-temperature alloy is used as the outermost coating, the porosity is low, the components are uniform, and certain mechanical properties are achieved while high temperature resistance is achieved. According to the composite coating disclosed by the invention, special powder components and a preparation process are adopted, so that the coating is difficult to deform or peel off in a long-time high-temperature environment, a base material is effectively protected, and the service life of the base material is prolonged.

Disclosed in the present invention is a radiation-insensitive single-mode optical fiber, comprising a core, a first cladding, and a second cladding which are sequentially arranged from inside to outside, or comprising a core, a first buffer layer, a first cladding, a second buffer layer, and a second cladding which are sequentially arranged from inside to outside. The core, the first buffer layer, the first cladding, the second buffer layer, and the second cladding are all made of quartz glass doped with a cerium element, an aluminum element, and a fluorine element. The contents of the cerium element, the aluminum element, and the fluorine element are constant in the radial directions of the core, the first cladding, and the second cladding, respectively, and linearly vary in the first buffer layer and the second buffer layer, respectively. In the present invention, by regulating and controlling the contents of the cerium element, the aluminum element, and the fluorine element in the core, the first cladding, and the second cladding of the optical fiber, the stress distribution of the optical fiber is optimized, the residual stress is reduced, and the generation of fatigue bonds and wire drawing defects in the optical fiber is reduced, thereby improving the radiation resistance of the optical fiber.

The invention discloses a production method for reducing flaw detection defects of wind power gear steel, and belongs to the technical field of ferrous metallurgy. According to the method, an electric furnace-LF-VD-continuous casting process route is adopted, the mass fraction of an aluminum element Al in molten steel is controlled to be not lower than 0.018% in the LF refining process, and the mass fraction of [Al] is controlled to be higher than 0.010% all the time in the VD vacuum treatment process. And after VD vacuum breaking, aluminum is supplemented in time, the mass fraction of Al is increased to 0.015%-0.020%, calcium treatment is reasonably carried out, and the mass fraction of Ca in molten steel is controlled to be 0.0006%-0.0009%. By accurately controlling the component change of the molten steel in the VD process, the formation of CaO-MgO-Al2O3-SiO2 inclusions with high SiO2 content is effectively inhibited, the large-size ultrasonic flaw detection defects in the wind power gear steel are remarkably reduced, and the internal quality of the steel is improved. The method is simple in process and remarkable in effect, and has a good industrial application prospect.

The invention relates to the technical field of aluminum sulfate, in particular to a method for preparing aluminum sulfate. According to the method, the process of leaching the aluminum element from the aluminum ash and removing impurities in the prior art is optimized, the leaching rate of the aluminum element in the aluminum ash is greatly increased by two steps of alkaline leaching and ultrasonic-assisted alkaline leaching in the alkaline leaching process, the reaction conditions are mild, high temperature and high pressure are not needed, the nitrogen removal efficiency is high, meanwhile, the aluminum loss in the aluminum leaching process is reduced, and the method is suitable for industrial production. The organic complexing impurities are precipitated, and the precipitate generated by the complexing impurities is adsorbed by using the hydrogel as a carrier, so that the difficulty of impurity removal, precipitation and filtration is reduced, and the prepared aluminum sulfate is high in purity.

The invention discloses a preparation method of a near-stoichiometric aluminum-doped silicon carbide fiber, which comprises the following steps: doping PMS with an aluminum element, blending with PCS, and sequentially carrying out melt spinning, non-melting treatment, high-temperature pyrolysis, high-temperature sintering and the like to obtain the aluminum-doped silicon carbide fiber with a C / Si atomic ratio close to an ideal value. And the near-stoichiometric ratio regulation and control of the silicon carbide fiber components are realized.

The invention provides a magnesium alloy, a magnesium alloy shell and electronic equipment. The magnesium alloy comprises the following components in percentage by weight: 2.5%-4.5% of aluminum, 0.5%-1.0% of zinc, 0.2%-0.8% of manganese, 0.01%-1.0% of titanium, 0.01%-0.5% of antimony and the balance of magnesium, additive elements and inevitable impurities, the additive element is a lanthanum-cerium mixed element, and the total weight percentage of the lanthanum element and the cerium element is 0.5%-1.5%. The magnesium alloy can be applied to a magnesium alloy shell, a small amount of low-price mixed rare earth (La / Ce) is added into an alloy of an Mg-Al-Zn system with the low Al content, the refining effect of trace Ti and Sb elements is matched, the corrosion resistance of the magnesium alloy can be greatly improved, meanwhile, the use amount of the rare earth element and the aluminum element is reduced, the manufacturing cost is reduced, and the service life of the magnesium alloy is prolonged. The method is suitable for mass production of electronic products.

A toner including: a toner particle; and an inorganic fine particle, wherein the inorganic fine particle contains a strontium titanate fine particle, a Si-containing protrusion portion is present at a surface of the strontium titanate fine particle, and the toner contains an amorphous polyester resin and an aluminum element at a surface of the toner particle.

The invention provides a laser welding method for a metal workpiece with an aluminum coating on the surface, at least two laser beams are symmetrically arranged in the welding advancing direction in the laser welding process, the quality factor M2 of the laser beams is smaller than 1.5, each laser beam irradiates a welding assembly, and the welding assembly is welded with the aluminum coating on the surface of the metal workpiece. More than two deep melting small holes and molten metal surrounding the small holes are formed; under the irradiation of laser beam energy, the welding zone of the assembly is melted to form an overall slender molten pool, and the front edge of the molten pool tends to the vertical advancing direction to form a nearly rectangular morphology front end; the multiple deep penetration small holes drive surrounding liquid metal to flow and enable an aluminum coating on the surface of the weldment assembly to be melted, and distribution of aluminum in a molten pool tends to be uniform. According to the method, multiple laser beams are provided to act on laser welding of butt joint of the steel with the aluminum coating, so that the aluminum element is uniformly distributed in a welding seam, the influence of aluminum on a welding joint is weakened, the method is low in cost and simple to operate, and the laser welding joint with excellent performance can be obtained.

The invention provides lightweight high-strength ceramsite and a preparation method thereof, and relates to the technical field of metallurgical industry solid waste recycling. According to the lightweight high-strength ceramsite provided by the invention, the steel slag is taken as a main raw material, the smelting slag and the coal gangue are taken as auxiliary materials, after reasonable proportioning and mixing, grinding and screening are performed, a ceramsite green body is prepared, after drying, the green body is put into a high-temperature kiln to be roasted, and finally a cooled ceramsite product is obtained. In the process, the smelting slag is used as a material which is rich in silicon and aluminum elements and has certain viscosity, so that the problem of poor plasticity of the steel slag can be solved, the quality of the ceramsite can be effectively improved, and the strength of the ceramsite green body can be improved; the coal gangue provides carbon elements and can provide heat for a roasting section, so that the reduction of energy consumption is facilitated. Due to the addition of silicon and aluminum elements, the final mineral phase is ordinary pyroxene, the cylinder compressive strength of the sintered ceramsite is increased, and the water absorption rate of the sintered ceramsite is reduced.

Provided are a positive electrode active material and a preparation method, an electrode sheet, an energy storage device, and an electric device. The positive electrode active material comprises LiMnaFe1-a-b-cM1bM2cPO4, wherein 0＜a≤0.8, 0＜b≤0.1, 0＜c≤0.1, M1 comprises titanium element, and M2 comprises aluminum element. The positive electrode active material is granular; and the doping amount of titanium element in the central region of a positive electrode active material particle is greater than that in the surface layer of the positive electrode active material particle, and the doping amount of aluminum element in the central region of a positive electrode active material particle is less than that in the surface layer of the positive electrode active material particle. The positive electrode active material has both relatively high structural thermal stability and relatively low impedance, and is beneficial to considering both the safety performance and electrochemical performance of a battery.

The invention discloses an in-situ synthesis Al2O3 reinforced low-density iron-based composite material and a preparation method thereof. The low-density iron-based composite material comprises an iron matrix and an Al2O3 reinforced phase distributed in the iron matrix, the Al2O3 reinforced phase is generated by an in-situ reaction of an oxygen element in Fe2O3 and an aluminum element in a melt in a smelting process, and the Al2O3 reinforced phase accounts for 1-5% of the iron matrix in volume percentage. According to the method, Al2O3 reinforced particles are produced in situ in an iron matrix by utilizing an in-situ synthesis technology, so that the wettability of Al2O3 and the iron matrix is effectively improved, metallurgical bonding is formed, the overall mechanical property and durability of the material are favorably improved, and the prepared iron-based composite material has the characteristic of low density and is suitable for industrial production. The requirements on light-weight materials in modern engineering are met.