152results about How to "Improve electrochemical activity" patented technology

A novel nanocarbon composite structure is provided having trapped ruthenium oxide. By using Ketjen black, and through chemical-mechanical effect utilizing an ultracentrifugal reaction field, both the specific surface area of ruthenium oxide and space of electrode material are expanded to have nanoparticles of ruthenium oxide highly dispersed in a graphene layer. This nanocarbon composite structure having trapped ruthenium oxide exhibits high electrochemical activity and is suitable for use as an electrical energy storing device, such as a large-capacity capacitor.

The invention relates to the field of battery manufacturing and energy storage, in particular to a preparation method of a bismuth-base catalyst/carbon nanofiber combination electrode for an all-vanadium redox flow battery. Firstly, spinning solution required for an experiment is prepared and then bismuth salt and the spinning solution are uniformly mixed. According to an electrostatic spinning method, a required nanofiber film is prepared and then the nanofiber film is pre-oxidized in the air and is carbonized in an inert atmosphere tube furnace so as to obtain the required bismuth-base electrocatalyst/carbon nanofiber combination electrode. After the obtained electrode material is cleaned and dried, testing of related electrochemical performance representation and charge-discharge properties can be carried out on the electrode material. The carbon fiber diameter, which is prepared according to the preparation method, is in the nano class; compared with a specific surface area of a conventionally used electrode material, the specific surface area of the bismuth-base catalyst/carbon nanofiber combination electrode is greatly increased. Moreover, the carbon nanofibers are compounded with a high-activity bismuth-base electrocatalyst, and thus, electrochemical activity of the electrode can be greatly improved, so that energy efficiency of the all-vanadium redox flow battery is greatly improved.

The invention discloses a preparation method and application of a non-enzymatic electrochemical immunosensor based on dopamine biomemetic modification and relates to the fields of nano-science, biological immune technology, electrochemical sensing and the like. An electrode is functionalized by utilizing dopamine biomemetic modification, and platinum, silver, palladium and other metal nanoparticles with enzymatic activity are synthesized in situ by utilizing the reduction characteristic of a poly-dopamine modification layer; an antibody is immobilized on the surface of the electrode by means of the interaction of the metal nanoparticles and poly-dopamine modification layer; electrochemical immunoassay on a tumor marker can be realized based on the electrocatalytic effect of the metal nanoparticles to an H2O2 reduction reaction and the identification effect of the antibody molecule to an antigen. The method is simple in steps, easy to operate and low in cost, has a high electrochemical activity and excellent response performance, can solve the problem of difficult nano-material synthesis in a conventional method and lack of simple and effective method, is applicable to preparation of multiple tumor marker immunosensor electrodes, and has a wide application prospect in scientific research and clinical application.

The invention discloses a super-wide-temperature-range nickel-hydrogen battery. The battery comprises an iron shell as well as a nickel electrode, a hydrogen electrode, a diaphragm and an electrolyte solution mounted in the iron shell, wherein the nickel electrode takes foam nickel as a substrate material; the space in foam nickel is filled with a positive electrode active substance Ni(OH)2, a conductive agent, an additive and a binder; the hydrogen electrode takes a porous nickel-plated steel belt, a copper net or foam nickel as a substrate material; the porous nickel-plated steel belt, the copper net or foam nickel is coated with a negative electrode active substance, namely, hydrogen storage alloy powder, the conductive agent, the additive or the binder; and the electrolyte solution is a mixture of a potassium-rich alkaline aqueous solution and sodium tungstate or tungstic acid crystals. The invention furthermore discloses a manufacturing method for the super-wide-temperature-range nickel-hydrogen battery. According to the super-wide-temperature-range nickel-hydrogen battery disclosed by the invention, the ratio of 0.2C discharge capacity to normal-temperature capacity maximally can reach 70-80% in an environment with the temperature of -45 DEG C; and the ratio of 0.2C discharge capacity to normal-temperature capacity of the nickel hydrogen battery maximally can reach 85-95% in an environment with the temperature of 70 DEG C. Moreover, the manufacturing method is simple and suitable for large-scale production.

The invention belongs to the technical field of a nanomaterial, and specifically relates to an iron-nitrogen-doped graphene porous material with dual-site catalytic oxygen reduction activity, and a preparation method and an application therefor. The porous material is formed by embedding graphite-carbon-coated iron carbide into a nitrogen-doped porous graphene band network structure; the preparation method for the iron-nitrogen-doped graphene porous material comprises the steps of preparing a graphene oxide solution; adding a proper amount of conductive macromolecular pyrrole to the graphene oxide solution; obtaining uniform hydrogel through a hydrothermal process; performing oxidative polymerization on the hydrogel by ferric iron; then dispersing the hydrogel into a fresh ferric iron solution to complete adsorption; then performing drying and high-temperature carbonization thermal processing; and finally removing non-active and free iron phase from the reaction system by dilute acid so as to obtain the iron-nitrogen-doped graphene porous material. The porous material can be used as the negative electrode catalyst for a fuel cell, and shows quite high catalytic oxygen reduction activity, so that the porous material has quite important research meaning and bright application prospects.

The invention relates to the technical field of preparation of nanometer materials, and discloses a functionalized polydopamine derived carbon layer coated carbon substrate preparation method and application. The preparation method comprises the following steps: 1) immersing a carbon substrate into a trihydroxymethyl aminomethane aqueous solution, the pH value of which is adjusted to be alkaline, and then, reacting with dopamine hydrochloride to obtain a polydopamine coated carbon substrate; 2) carrying out high-temperature carbonization on the obtained polydopamine coated carbon substrate to obtain a polydopamine derived carbon layer coated carbon substrate; and 3) enabling the obtained polydopamine derived carbon layer coated carbon substrate to react with a bimetallic saline solution to obtain a functionalized polydopamine derived carbon layer coated carbon substrate. The functionalized polydopamine derived carbon layer coated carbon substrate is stable in structure, is high in electrochemical activity, and has a series of advantages of high specific capacitance and good rate capability and the like when serving as the electrode material of a super capacitor; and the preparation method thereof is simple and easy to operate.

The invention relates to a preparing method of a sodium-ion battery cathode material, and particularly relates to a preparing method of a manganese-based sodium cathode material. The preparing method includes mixing a sodium-containing compound and a manganese-containing compound according to a ratio that the molar ratio of Na to Mn is larger than 1; sintering at 600-1000 DEG C for 6-20 h; cooling to the room temperature to obtain a sintered product; smashing the sintered product; performing washing/solid liquid separation repeatedly for a plurality of times; and drying to obtain a final product. According to the method, the excess sodium-containing compound is adopted to increase the solid phase reaction speed between the sodium-containing compound and the manganese-containing compound and to increase the conversion rate. Modification of an alkaline intermediate is utilized to enhance the electrochemical activity of the product. Excess sodium-containing by-products after the reaction is finished can be removed in the washing/solid liquid separation step.

The invention discloses a silicon-based cathode composite material for a lithium ion battery and a preparation method thereof. The cathode composite material is a Si/CuOx/C composite material (0<=x<=1) with a porous structure. Silicon with a porous structure is used as a base, and CuOx particles are inserted in the pores, and carbons with different forms are distributed on a surface and pore walls of the silicon-based material. The preparation method of the cathode composite material comprises steps that silicon material realizes pore-forming through an in situ catalytic reaction between silicon and halogenated hydrocarbon, and reaction condition parameters are regulated to control pore size, distribution and amount of porosity of the silicon material; a post-modification technology is employed to carry out modifications on the surface and the pore walls of the porous silicon, so as to obtain the Si/CuOx/C composite material with a porous structure. The porous silicon-based cathode composite material has low production costs, simple process and no pollution, and is suitable for industrialized production; besides the porous silicon-based cathode composite material has high charge and discharge capacity, small initial irreversible capacity and good cycle performance.

The invention provides a preparation method of a supported platinum-based alloy catalyst. The catalyst can be used as a low temperature fuel cell catalyst. The preparation method comprises the steps of taking ethylene glycol as a solvent and stabilizer, dispersing a carrier in the solvent, and reducing platinum and non-platinum precursors by strong reducing agents such as borohydride, hydrazine hydrate and tetrabutyl borohydride to obtain supported platinum-based alloy nanoparticles. The preparation method adopted by the invention is simple, effective and free of a problem of difficult removalof the stabilizer. The prepared alloy catalyst has a small particle size and uniform particle size distribution, and has good dispersion on the carrier at the same time. In addition, the catalyst canshow high area specific activity and unit mass Pt specific activity for oxygen reduction reaction, can effectively reduce the platinum consumption and has potential application prospects in the low temperature fuel cell.

A method for producing gas diffusion electrodes, in particular for use in electrolysis cells, as well as electrodes and their uses are described. A method of the present invention involves first, a sheet-like structure is produced by means of a pair of rolls by rolling a powder mixture containing at least one catalyst or a catalyst mixture and a binder, and then the sheet-like structure is connected to an electrically conductive catalyst support by rolling by means of a pair of rolls. In one embodiment the clamping force of the rolls is preferably kept constant in the range from 0.2 kN/cm to 15 kN/cm.

The preparation method for nano composite anode material of V2O5-carbon-sulphur and LiVO3-carbon-sulphur comprises: using NH4VO3 or V2O5 as material to prepare V2O5 sol; grinding and mixing the carbon material (acetylene black, acetylene black or active carbon) and elemental sulfur; dispersing the said mixture into V2O5 sol; drying and thermal treating to obtain the nano V2O5-carbon-sulphur composite material; or dispersing the mixture into V2O5 sol contained LiOH to final obtain another LiVO3-carbon-sulphur composite material. Both the products have high electrochemical activity and high density. This invention has simple process and low cost.

The invention discloses a preparation method of molybdenum carbide microspheres. The method comprises the following steps of: (1) adding strongly alkaline anion exchange resin to a molybdate solution, carrying out stirring reaction at a room temperature, obtaining a molybdenum ion-resin compound through washing and suction filtration, and drying the molybdenum ion-resin compound to obtain ion exchange resin microspheres containing a molybdenum element; and (2) putting the ion exchange resin microspheres containing the molybdenum element obtained in the step (2) into a ceramic crucible, roasting the microspheres at 700-1,000 DEG C in the presence of an inert gas for 1-4 hours, and naturally cooling the product to a room temperature to obtain the molybdenum carbide microspheres. The invention further discloses application of the molybdenum carbide microspheres in hydrogen production through electrolysis of water. The preparation conditions are low in demands; the raw materials are cheap and available; the prepared molybdenum carbide microspheres have electrochemical activity of catalytic low overpotential and good stability.

The invention discloses a rare-earth-modified aluminium alloy anode plate and a preparation method thereof. The anode plate is prepared from raw materials such as an aluminium block, a magnesium block, a bismuth granule, a tin granule, a gallium granule, an indium granule, a lanthanum granule and a cerium granule in the mass ratio of (96.6-99.31):(0.5-2):(0.1-1):(0.05-0.2):(0.01-0.1):(0.01-0.05):(0.01-0.03):(0.01-0.02). Proper amounts of various alloy elements are weighed according to the formula during alloy casting and molten in a resistance furnace crucible at the temperature of 750-800 DEG C, and then alloy melt is poured into a water-cooling steel mold for use. The solid solution temperature in alloy solid solution heat treatment is in a range of 500-560 DEG C, and the solid solution time is in a range of 5-8 h. The single-pass rolling temperature in an alloy rolling machining technology is in a range of 400-450 DEG C, and the single-pass deformation is in a range of 35-45%. The rare-earth-modified aluminium alloy anode plate is low in self-corrosion speed and high in electrochemical activity during high-current-density discharging and meets performance requirements of high current efficiency, stable discharging and small hydrogen evolution amount during movement of an alkaline aluminum battery.

The invention discloses a titanium-based carbon nanotube supported copper/palladium bimetallic catalyst and a preparation method thereof. The catalyst is characterized in that double metals (namely copper and palladium) are used as catalytic active components, a carbon nanotube is used as a supporter, and a titanium plate is used as a substrate. The preparation method comprises the following steps: respectively pretreating the titanium plate and the carbon nanotube; taking the treated titanium plate as an anode, taking dispersed carbon nanotube suspension as a deposition solution, and depositing the carbon nanotube on the titanium plate through electrophoresis; and taking a dried titanium-based carbon nanotube film as a supporter, and synchronously depositing the double metals (namely copper and palladium) through electrochemical reduction in a plating solution containing the double metal elements (namely copper and palladium), thus obtaining the titanium-based carbon nanotube supported copper/palladium bimetallic catalyst. The titanium-based carbon nanotube supported copper/palladium (Ti-CNT-CuPd) bimetallic catalyst prepared by the invention has high and stable electrochemical reduction activity, and can be used as a reduction catalyst for ions such as nitrate, bromate and the like in a water body.

The invention relates to the field of battery manufacturing and energy source storage, in particular to a preparation method of a nano graphite powder/carbon nanofiber composite electrode for an all-vanadium redox flow battery. Firstly, a spinning solution required by an experiment is prepared, and then nano graphite powder with different particle sizes and the spinning solution are uniformly mixed. By an electrospinning technology, a required nanofiber membrane is prepared, and then is pre-oxidized in the air and is carbonized in an inert atmosphere tubular atmosphere furnace to obtain a required nano graphite powder/carbon nanofiber composite electrode. According to the all-vanadium redox flow battery composite electrode prepared by the method provided by the invention, the carbon fiber diameter is at the nanoscale, and the carbon fiber is compounded with nano graphite powder with high electrical conductivity, so that the roughness of the fiber is substantially increased, and thus the specific surface area of the electrode is two orders of magnitude larger than that of the conventionally used electrode material. Meanwhile, the high-activity nano graphite powder enables the electrochemical activity of the electrode to be improved, so that the energy efficiency of the all-vanadium redox flow battery is greatly improved.

The invention discloses preparation method and application of a polyaniline nanometer flower-modified carbon cloth electrode, and belongs to the technical field of an electrode material. Carbon clothis used as a substrate, in-situ polymerization of polyaniline is performed on a surface of the carbon cloth by controlling a proportion between an aniline monomer and ammonium persulfate, and the polyaniline nanometer flower-modified carbon cloth electrode is obtained after washing and drying. The polyaniline nanometer flower-modified carbon cloth electrode obtained by preparation can be used as amicrobial fuel cell positive electrode and is endowed with extremely high current density and power density compared with a carbon cloth electrode which is not modified. The preparation process is simple and is low in cost, a microbial fuel cell is good in power generation performance, and the preparation method has very important significance to practical application of the microbial fuel cell.

The invention relates to a method for hydrothermally repairing an invalid lithium cobalt oxide material in a lithium ion battery by ultrasonic field enhancement. The method comprises the concrete steps as follows: disassembling the lithium ion battery to obtain an anode aluminum foil; calcining for 2-3 h at the temperature of 400-450 DEG C, and vibrating to enable lithium cobalt oxide to drop from a current collector foil so as to obtain lithium cobalt oxide powder; immersing the lithium cobalt oxide powder into a lithium hydroxide solution, mixing, pouring a mixed solution into an ultrasonic reaction kettle, heating to 150-180 DEG C, applying ultrasonic waves, and radiating for 6-12 h; and cooling the ultrasonic reaction kettle, taking out the mixed solution from the ultrasonic reaction kettle, washing, filtering and drying to obtain the repaired lithium cobalt oxide material. According to the method, lithium cobalt oxide can more easily drop from the current collector foil, organic matters attached on the surface of lithium cobalt oxide can be effectively removed, the content of lithium ions in the invalid lithium cobalt oxide material is remarkably increased, the electrochemical performance of lithium cobalt oxide is remarkably improved, and the repaired lithium cobalt oxide material can again serve as an anode material for producing the lithium ion battery. In addition, the lithium cobalt oxide material in the waste lithium ion battery can be effectively treated, so that considerable economic benefits are obtained while the environmental pollution is reduced.

The invention discloses a graphene coated lithium titanate cathode and a preparation method thereof. The graphene coated lithium titanate cathode is prepared from the following components including lithium titanate and flake graphite according to the ratio of 50 to 1-400 to 1, and preferentially, 100 to 1. The preparation method comprises the following steps: soaking the flake graphite with N-methyl pyrrolidone, serving as a solvent, softening by infiltration, then putting a lithium titanate cathode material after softening by infiltration into a mixed solution of the flake graphite and the N-methyl pyrrolidone, then putting the mixed solution of the lithium titanate cathode material after softening by infiltration, the flake graphite and the N-methyl pyrrolidone into a sand mill, grinding with a zirconia ball, serving as a sand milling medium, filtering to remove the N-methyl pyrrolidone solvent, evaporating, drying, completely removing the residual N-methyl pyrrolidone solvent, and thus preparing the graphene coated lithium titanate cathode. According to the graphene coated lithium titanate cathode and the preparation method disclosed by the invention, proved by charge-discharge cycle tests by assembling batteries, the capacity of the graphene coated lithium titanate cathode is increased, and the phenomenon of gas expansion is improved.

The invention discloses a composite graphene aerogel electrode. Aerogel is doped with at least two kinds of elements of nitrogen, boron and sulfur; a C-B bond, an N-B bond and a C-S bond are formed ina graphene structure, so that the aerogel electrode forms an atomic bridging layered porous structure; the mass specific capacitance of the aerogel electrode can be as high as 450F.g<-1>; the preparation method comprises the steps of 1) cleaning of an electrode substrate; 2) preparation of graphene hydrogel; 3) dialysis of graphene hydrogel; 4) preparation of graphene aerogel; and 5) preparationof the graphene aerogel electrode. The composite graphene aerogel electrode disclosed in the invention has high electrochemical activity; in addition, the graphene porous structure has very high elasticity recovery, so that the graphene aerogel has high mechanical stability. When the graphene aerogel electrode is used for a current collector of a supercapacitor, the mass specific capacitance can reach 450F.g<-1> at the current density of 2A.g<-1>, so that the composite graphene aerogel electrode has wide application prospect.

The invention provides an anode material for an aluminum-air cell and a preparation method thereof. The anode material comprises, by mass, 0.1-0.2% of Ga, 0.05-0.15% of Pb, 0.01-0.05% of Bi, 0.005-0.015% of Ti, 0.001-0.003% of B, less than or equal to 0.003% of Fe, less than or equal to 0.003% of Si, less than or equal to 0.005% of Cu, and the balance Al and other inevitable impurities. The preparation method of the anode material comprises the steps of melting and preparing of aluminum alloy melt, furnace injection blowing and refining, online grain refinement, online degassing and filtration, ultrasonic stirring and semicontinuous casting, cast ingot homogenization, and heating and extrusion. Through optimization to the compositions of the anode material and the preparation method thereof, the cleanliness and composition homogenization of the material are improved, the compactness and continuity of an oxidation film are destroyed, the electrochemical activity of the material is improved, and the hydrogen evolution self-corrosion rate is reduced. The anode material for the aluminum-air cell, provided by the invention, has the advantages of high electrochemical activity, low hydrogen evolution self-corrosion rate and high material utilization rate.

This invention relates to an electrode active material used in Li ionic batteries and its preparation method, in which, the material is prepared by depositing a nm compound film made up of Li₂S and a transition metal element Co with pulse laser and the size of the compound is smaller than 50nm, the specific volume is varied in the sphere of 400-650mAh/g along with the difference of Co and presents very good stability in the repeated charge/discharge process.

The invention discloses a preparation method of a graphene-ceramic composite material. The preparation method comprises the following steps of: (1), penetrating cerate (or zircon salt), auxiliaries and graphene oxide through alcohol dissolving auxiliaries, ultrasonically dispersing the materials uniformly for co-decomposing into metal oxides to obtain a composite material; (2), adding organic adhesive solvent to the graphene-metal oxide composite material for sufficiently mixing and grinding; pressing the mixture into a strip-shaped composite sample by adopting a dry-press process, placing the composite sample in a vacuum tube furnace; and controlling the sintering condition by ventilating a gas mixture of a certain proportion, cooling to the room temperature to obtain the graphene-ceramic composite material. The preparation method of the graphene-ceramic composite material disclosed by the invention can be used for improving the dispersibility and cycling stability of ceramic oxide particles, increasing a three-phase interface among the ceramic oxide particles and improving the electrochemical activity of the composite material, so that the ceramic material has the advantages of being low in density, high in strength, excellent in oxidation resistance, thermal scouring resistance, corrosion resistance and the like.

The invention belongs to the technical field of biomass materials and discloses a lignin-based bimetallic functionalized carbon material as well as a preparation method and application thereof. The invention provides the preparation method of the lignin-based metal functionalized carbon material. The method carrying out carboxylation modification on lignin, coordinating with transition metal to form a metal carboxylated lignin-based supramolecular precursor, co-doping with nonmetal heteroatoms, and carrying out high-temperature carbonization. The method comprises the following steps: S1, coordinating and combining carboxylated lignin with an iron and cobalt metal salt solution to obtain a bimetal carboxylated lignin-based supramolecular precursor; and S2, carrying out non-metal doping andhigh-temperature carbonization treatment on the metal lignin-based supramolecular precursor to obtain the modified lignin-based metal functionalized carbon material. An electrocatalytic oxygen evolution electrode prepared from the carboxylated lignin-based metal functionalized carbon material prepared by the preparation method disclosed by the invention shows excellent catalytic activity.

The invention discloses a selenium-doped ferrous disulfide carbon-coated composite material. The composition of the selenium-doped ferrous disulfide carbon-coated composite material is FeSe*S2-*@C, wherein x is 0.1-1.9. When applied to sodium ion batteries, the selenium-doped ferrous disulfide carbon-coated composite material can effectively inhibit volume expansion effects and increase actual specific capacity, rate capability and cycling performance. The invention also discloses preparation and application methods of the selenium-doped ferrous disulfide carbon-coated composite material.

The invention relates to a preparation method of nanometer nickel sulfide. The method comprises steps as follows: evenly mixing nickel acetate and sodium thiosulfate according to certain proportion, dissolving in deionized water, obtaining mixed solution; adding the mixed solution in an autoclave, reacting for certain period of time at certain temperature; cooling, carrying out centrifugal washing, drying, obtaining black solid matter, namely nanometer banding NiS with hexagonal phase, wherein the particle diameter is 10-500 nanometers. The invention has advantages that the preparation material is low in cost and price and is green and environment protective, the preparation method is simple and easy in operation, the prepared product is nanometer material, is even in appearance and particle and has good electrochemical activity, when being taken as the cathode material of the aluminium ion battery, the battery specific capacity of the product reaches 100 mAh/g, and the product can circulate stably.

The invention discloses a biosensor based on an aptamer and a manufacturing method and application thereof and belongs to the field of biochemical technique. According to the biosensor based on the aptamer, n-octadecyl mercaptan is automatically assembled on a gold film, the n-octadecyl mercaptan is combined with carboxyl group graphene oxide through intermolecular force, activating treatment is carried out on the carboxyl group graphene oxide to enable carboxyl to be converted into an active ester group, and an amido bond is formed through the active ester group and amino acid on molecule of the aptamer to enable the aptamer to be fixed on the surface of the carboxyl group graphene oxide. According to the biosensor based on the aptamer, the electrochemical activity is good, the aptamer can be well fixed, and the biosensor can be used for detection of various kinds of target protein and can be applied to the fields such as biomedicine, food safety and environmental monitoring. The manufacturing method of the biosensor based on the aptamer is simple and easy to operate. Due to the fact that hydroxyl and epoxy group which are on the graphene oxide are converted into the carboxyl due to the adoption of NaOH and ClCH2COONa, the COOH functional group content is high, the good electrochemical activity is achieved, and the aptamer can be well fixed.

The present invention relates to a preparation process of a phosphorus-and-nitrogen-doped graphene porous carbon composite material. The preparation process comprises the following steps: (1) hydrothermal reaction: dissolving a nitrogen source into deionized water, adding a graphene oxide solution and performing ultrasound for a pre-set time, adding a phosphorus source and performing ultrasound for a pre-set time to obtain a mixed solution, and then transferring the mixed solution to a high pressure reactor and performing the hydrothermal reaction to obtain a hydrogel, wherein the nitrogen source is one or more of aromatic polyamines, and the phosphorus source is phosphoric acid or phosphate; (2) oxidative polymerization: adding the hydrogel in step (1) into a ferric chloride solution after the hydrogel is cooled, and sealing and standing the mixed solution under a predetermined temperature for a pre-set time to obtain a composite hydrogel; and (3) carbonization activation. The preparation method has the advantages of simplicity, low cost and high production efficiency, no pollutants generate, and the prepared phosphorus-and-nitrogen-doped graphene porous carbon composite materialhas excellent specific capacitance value, high cycle stability, high energy density and excellent electrochemical performance when the material is applied to super capacitor electrodes.

The invention discloses a method for recycling a lithium iron phosphate positive electrode material in a waste lithium ion battery, belonging to the field of recovery technologies for lithium iron phosphate positive electrode materials in waste lithium ion batteries and the field of alkaline secondary batteries. According to a technical scheme in the invention, the lithium iron phosphate positive electrode material in the waste lithium ion battery is used as a raw material and uniformly mixed with a ferric salt and an organic additive so as to obtain a mixture; then the mixture is subjected to calcining in an inert atmosphere so as to prepare a lithium iron phosphate-based composite material; and the lithium iron phosphate-based composite material is used for preparation of the negative electrode of an alkaline secondary battery. The method provided by the invention can efficiently recycle waste lithium ion battery positive electrode materials and apply the recycled waste lithium ion battery positive electrode materials to the negative electrode of an alkaline secondary battery, so cyclic regeneration and utilization of the waste lithium iron phosphate material are realized.

The invention discloses relates to a preparation method and application of a f nanometer nickel sulfide-graphene composite electrode material, belonging to the field of electrochemistry. The materialis prepared by loading graphene oxide on carbon fiber cloth, reducing graphene oxide while depositing nanometer nickel hydroxide on the surface of the graphene oxide/carbon fiber cloth by a potentiostatic deposition method, so as to obtain a nickel hydroxide-graphene composite material, and finally reacting with sodium sulfide to obtain nanometer nickel sulfide-graphene composite material. The present invention is mainly used in the field of electrochemical energy storage and electrochemical sensors.

The invention discloses a preparation method of hydroxyapatite-coated lithium titanate. The method comprises the following steps: respectively preparing a lithium source solution of a certain concentration and a titanium source solution of a certain concentration; adding the lithium source solution and the titanium source solution to sol with a certain ratio of hydroxyapatite, and carrying out water bath and magnetic stirring to form gel; drying the gel to prepare a precursor; and grinding, crushing and calcining the precursor to obtain a hydroxyapatite-coated lithium titanate anode material. According to the preparation method of the hydroxyapatite-coated lithium titanate, the hydroxyapatite can effectively coat the surface of the lithium titanate, inhibits growth of particles, and shows relatively high electrochemical activity. The pH value of the material can be lowered; and the hygroscopic property of the material is inhibited. According to the preparation method, the required raw materials are low in price; the operation is simple and feasible; and the prepared lithium titanate anode material has excellent electrochemical properties.