148 results about "Cobalt oxyhydroxide" patented technology

The invention discloses a preparation method for spherical cobalt oxyhydroxide. Prepared spherical cobalt oxyhydroxide can be directly used as a raw material for preparation of lithium cobalt oxide. According to the invention, wet processing and doping of trace metal elements are adopted to improve related performance like cycle and voltage of the product; the method is simple and produces no pollution; and the product has the advantages of uniform distribution of doped elements, high density and a good sphericity degree.

The invention relates to a preparation method for nickel hydroxide, which is used as a Ni-H storage battery positive material, coated with gamma hydroxy cobalt oxide. The preparation includes that the sphere surface of nickel hydroxide is coated with a layer of cobalt hydroxide firstly; then, under the conditions of high-density sodium hydroxide and oxygen, the cobalt hydroxide layer coated on the surface is oxidized the gamma hydroxy cobalt oxide, or the treatment of embedding doped metals is exerted on the gamma hydroxy cobalt oxide layer. By controlling the coating layer to be the cobalt hydroxide presenting a shape of flake, the method makes the resulted conducting network coated with the coating layer of gamma hydroxy cobalt oxide more uniform, more integrated and better conductive, and thus attributes the nickel hydroxide positive active material coated with gamma hydroxy cobalt oxide with some characteristics of high recovering rate of over-discharging capacity, good performance of big current discharging, low self-discharging, long lifetime of cycling use and so on.

The invention discloses a preparation method of cobalt oxyhydroxide. In the method, a cobalt salt solution is used as a raw material; precipitation and oxidation reaction are performed at the same time in an alkaline solution in the presence of an oxidant; and the precipitate is subjected to washing, impurity removal, drying, granulation, mixing and screening to obtain cobalt oxyhydroxide of which D50 is 10-20 microns. Compared with lithium cobaltate prepared by taking cobaltosic oxide as the raw material traditionally, the compaction density of the lithium cobaltate prepared from cobalt oxyhydroxide disclosed by the invention can be obviously improved by 0.2-0.3g/cm<3>, and the capacity and cycling performance are also obviously improved. Meanwhile, compared with the traditional preparation technology of the battery positive material raw material cobaltosic oxide, the technology disclosed by the invention is low in cost and low in energy consumption, is more environment-friendly and realizes economic and social benefits.

The invention discloses a method for producing hydroxy cobalt oxide, comprising the following steps of: firstly, preparing a cobaltous sulfate solution with cobalt content of 75-85g/l; adjusting a pH value of the solution to be 3.0-4.5; adding EDTA (Ethylene Diamine Tetraacetic Acid) into the solution according to the proportion of cobalt to EDTA of 100:(1-3); preparing sodium hydroxide solution with alkali concentration of 7-9mol; performing cocurrent flow on two solutions and flowing into a reaction groove; introducing the air for performing synthetic reaction; controlling the reaction temperature to be between 50 and 70 and a pH value to be between 10.0 and 12.0 for reacting for 15-25 hours; flowing into an aging groove for aging for 50-60 minutes; and finally, filtering, washing and slurrying to prepare a hydroxy cobalt oxide solid product. According to the method, the production process is controllable, particles of the product are uniformly distributed with good consistency, the shape is spherical and the product has good dispersibility; and the production process is free of ammonia nitrogen pollution, so that continuous production is realized, and the equipment utilization rate and the production efficiency are improved.

A method of preparation of spherical tricobalt tetraoxide, including at least oxidizing a bivalent cobalt salt in a wet environment and in the presence of a precipitant, a complexing agent, and an oxidant to yield spherical cobalt oxyhydroxide.cobalt hydroxide according to the following equation Co²⁺+3OH⁻+O→CoOOH.Co(OH)₂; oxidizing the spherical hydroxy cobalt oxyhydroxide.cobalt hydroxide to yield spherical tricobalt tetraoxide according to the following equation 6 CoOOH.Co(OH)₂+O→4 Co₃O₄+9 H₂O; and roasting the spherical tricobalt tetraoxide at low or intermediate temperature to yield a black powder. The method is easily practiced and suitable for mass production, and the resultant spherical tricobalt tetraoxide has stable structure, reliable properties, and high activity.

The invention provides a process for preparing lithium cobalt oxide of lithium-ion secondary battery cathode materials. The process includes that cobalt oxide or hydroxyl cobalt oxide powders and lithium carbonate powders are mixed according to a lithium/cobalt molar ratio of 1.0-1.1 and calcined in an atmosphere containing oxygen at the temperature of 850-1100 DEG C; obtained mixture is calcined for 5-55 hours in the atmosphere containing oxygen at the temperature of 850-1100 DEG C; calcined products are naturally cooled to reach room temperature and then grinded; laser scattered grain size distribution measuring device is used for classifying; lithium cobalt oxide semi-finished products are obtained by selecting an average grain diameter D50 of 8-20 micrometers; and a device with high-speed shear strength function is used for conducting coating composition treatment process on the surfaces of the lithium cobalt oxide semi-finished products. The process has the advantages of low raw material cost, high volume energy density, good safety, fine charge-discharge cycle performance, high pressurizing density and superior productivity.

The invention relates to a color developing agent and a preparation method and an application thereof. The color developing agent is prepared by mixing a CoOOH nano sheet suspension with 3, 3', 5,5'-tetramethyl benzidine water solution according to the molar ratio CoOOH nano sheets to 3, 3', 5,5'-tetramethyl benzidine of 2:1. The color developing agent is used for detecting ascorbic acid, and has high sensitivity and low detection limit.

This invention refers to cobalt hydroxide and preparation thereof, which is used to be coated on the surface of spherical nickel hydroxide of alkaline cell, wherein the cobalt is 1.0-10 % of total weight, the spherical nickel hydroxide contains 0-10 % of co-sinks of Co, Zn or hydroxide of Co and Zd. The preparation contains surface covering, filtering, washing, dewatering and drying. The spherical nickel hydroxide is oxidized to cobalt hydroxide with high conductivity in charge process, which effectively improves the conductivity of active substance, raises the availability of active substance, increases cell capacity, discharge capacity, reduces cell internal resistance, increases cycle service life and greatly raises the quality of cell positive active substance.

The invention relates to a lithium secondary battery cathode active material, a manufacturing method thereof and a lithium secondary battery. Even if an inexpensive cobalt raw material is used for the cathode active material of the lithium secondary battery, the cycle characteristics of the lithium secondary battery can be improved, and the battery capacity at low temperature can be improved. The positive electrode active material of the lithium secondary battery is a mixed powder of the following powders (A) and (B): (A) lithium cobalt oxide particles with an average particle size of 5-30 μm formed by sintering a mixture of cobalt oxyhydroxide and lithium compound Powder; (B) Lithium cobaltate particle powder with an average particle diameter of 0.1-10 μm and an average particle diameter smaller than the average particle diameter of the above-mentioned (A) obtained by sintering a mixture of tricobalt tetroxide and a lithium compound, wherein the above-mentioned (A) The compounding ratio with (B) is (A):(B)=95:5~60:40 by weight ratio, and the tap density is 1.8~3.0g/cm3.

The invention provides a method for preparing large particle size doped tricobalt tetroxide. The method takes a cobalt solution with a certain concentration as a cobalt source, a sodium carbonate solution is taken as a precipitant, an ammonia solution is taken as a complexing agent, a hydrazine hydrate solution is taken as a reducing agent, a mixed solution of a doping element solution and the complexing agent is taken as a dopant, and cobalt carbonate having a particle size of 20-30 [mu]m is synthesized in the shortest time through modes such as the reduction of the amount of crystal nucleusformed in the initial stage of synthesis. In the reaction process, the appropriate time is selected to add the doped solution into a reaction kettle to participate in the reaction; after the synthesiscomes to an end, under a certain pH value condition, a hydrogen peroxide solution with a certain solubility is utilized to oxidize the synthetic product into the hydroxyl cobaltous oxide, and the mixture is washed, dried and calcined to obtain the large particle size doped tricobalt tetroxide. The synthesis time of the process is short and is only 10-15 h, the product physicochemical index is good, the laser particle size is 15-25 [mu]m, the tap density is more than 2.0 g/cm3, the specific surface area is 1.0-3.0 m<2>/g, and the doping elements include Ni, Mn, Al, Cu, Ce, Y, Nb and Mg.

The invention relates to a preparation method of spherical hydroxy cobalt oxide. The preparation method comprises the following steps of: providing a control crystallization kettle; feeding a buffer agent which is used for controlling the reaction speed of reactants into the control crystallization kettle; feeding a cobalt salt solution and an alkaline solution into the control crystallization kettle with the buffer agent, wherein a cobalt salt solution and an alkaline solution are used as the reactants; and only stirring the reactants within the bottom area of the kettle body of the control crystallization kettle while the reactants react with each other, so as to prepare the spherical hydroxy cobalt oxide by means of control crystallization method.

The invention discloses a method for preparing a hydroxyl cobaltous oxide nanotube electrode. The method comprises the following steps: (1) mixing soluble cobalt salt, urea and foamed nickel in water, enabling the components to react sufficiently by using a hydrothermal method, washing, and drying so as to obtain a basic carbonate precursor; and (2) by taking the basic carbonate precursor as a supercapacitor electrode piece, performing cyclic voltammetry tests on the electrode piece, wherein ion exchange is generated in the test process so as to generate cobaltous hydroxide nanotubes, thereby obtaining hydroxyl cobaltous oxide nanotubes along with circulation. The method for preparing the hydroxyl cobaltous oxide nanotube electrode, which is disclosed by the invention, is simple in preparation process, and materials for ion exchange can be generated while the precursor is subjected to electrochemical testes, so that regulation and control on solution concentration, reaction time and reaction temperature are avoided, repeatability of the preparation process is improved, and prepared hydroxyl cobaltous oxide is good in stability and excellent in property.

The invention discloses a preparation method of a precursor of a positive material for a lithium ion battery, namely a spherical hydroxyl cobaltous oxide-cobaltosic oxide composite material. Existing lithium cobalt oxide precursor cobaltosic oxide is low in compaction and loose and cannot satisfy strong structural stability required by high cutoff voltage. The preparation method comprises the following steps: adding a complexing agent and an auxiliary into a cobalt salt solution at the same time; stirring uniformly to obtain a mixed solution; flowing the solution with alkaline liquor in parallel into a reaction kettle; adding a proper amount of an oxidizing agent; and synthesizing spherical hydroxyl cobaltous oxide with a certain pH value and at a reaction temperature and a stirring rotating speed.

The present invention provides a non-sintered type positive electrode for alkaline storage battery whose drop out of active material powder is suppressed while maintaining favorable charging-discharging properties such as utilization factor. A non-sintered type positive electrode constituted by an electrically conductive support, a nickel hydroxide powder coated by cobalt oxyhydroxide (COH), an additive made of COH powder, and a binder, in which the average particle size of the nickel hydroxide powder coated by COH is greater than that of the additive made of COH powder.

This invention relates to a method for covering alkyl Co2O on the surface of Ni(OH)2 including: 1, stocking: preparing Co2SO4: 0.5-2mol/L, NaOH solution:3-8mol/L, ammonia:6-10mol/L, 2, adding one portion of ball Ni(OH)2 in a reaction kettle with 6-12 portions of deionized water in it already to be mixed and control the temperature at 30-70deg.C, then adding 1 of Co2SO4 solution, 2-2.5 of NaOH solution and 0.8-1.5 ammonia in a reaction kettle to be reacted for 3-8 hours with the PH value at 10-11, then stopping feeding in the Co2SO4 solution and adding NaOH solution so that the PH value rises to 12-13.6, then adding chloros in 1-5% weight of Ni(OH)2 after the temperature rises to 80-90deg.C to be mixed for 30-60 minutes, 3, carrying out separation of the solid and liquid to be dried.

The invention relates to a method for fabricating an active substance of alkaline secondary battery positive pole, wherein, the invention comprises the steps that a bivalent cobalt salts solution is used to moisten a nickel hydroxide which is dried to get the nickel hydroxide containing the bivalent cobalt salts, the nickel hydroxide containing bivalent cobalt salts is contacted with an alkaline solution, the nickel hydroxide deposited with Co(OH)2 to be made under an oxidizing condition is contacted with an oxidizer, so the nickel hydroxide containing the cobalt oxy-hydroxide is made out, the weight ratio between the bivalent cobalt salts solution and the nickel hydroxide is 0.05-0.25:1; the cobalt oxy-hydroxide layer of the nickel hydroxide made by the invention is uniform, the granule shape of the nickel hydroxide is regular, which are all separately independent individual, the agglomeration problem can not occur, therefore, after the nickel hydroxide granule containing the cobalt oxy-hydroxide is fabricated into a battery, the performance of the batter is favorable; furthermore, the equipment used for the invention is simple, the reaction process does not have the conditions which need to be strictly controlled, the operation is easy and feasible.

The invention belongs to the technical field of preparing precursor of battery positive electrode material, in particular to a preparation method of doped cobalt tetroxide, and provides a preparationmethod of aluminum-magnesium-nickel-manganese doped spherical cobalt tetroxide. Cobalt liquid containing doped elements is prepared, EDTA is used as a complexing agent and synthesis is performed at acertain pH and temperature. Meanwhile, the doped elements are uniformly and fully precipitated, and finally the high-density spherical cobalt hydroxide with uniform doping is obtained and the doped cobalt tetroxide is obtained through centrifugation and calcination. The aluminum-magnesium-nickel-manganese doped spherical cobalt tetroxide prepared by the method has uniform particle size, good compactness, complete precipitation and uniform distribution of doped elements and stable and controllable process.

The method for producing a positive electrode active material for an alkaline storage battery is disclosed. The method includes a first oxidation treatment of a raw material powder comprising a nickel hydroxide solid solution and cobalt hydroxide to oxidize the cobalt hydroxide to a cobalt oxyhydroxide; and a second oxidation treatment of the powder obtained in the first oxidation treatment to oxidize the nickel hydroxide solid solution to a nickel oxyhydroxide solid solution.

The invention discloses a method for preparing bulk phase aluminum-doped cobaltosic oxide and belongs to the technical field of lithium ion batteries. The method comprises the following step: by taking a cobalt solution of a certain solution as a cobalt source, a sodium hydroxide solution as a precipitant, an ammonia water solution as a complexing agent, a hydrazine hydrate solution as a reducingagent, and an aluminum salt ethanol solution as a doping agent, carrying out a synthesis reaction, and putting an aluminum salt absolute ethyl alcohol solution into a reaction kettle to be subjected to reactions in a dispersion liquid addition mode a reaction process; after the synthesis reaction is completed, under a condition of a certain pH value, oxidizing a synthesis product into hydroxyl cobaltous oxide by using a hydrogen peroxide solution, washing a mixture, drying, and calcining, thereby obtaining a bulk phase aluminum-doped cobaltosic oxide product of which an aluminum element is uniformly distributed. The method is high in production efficiency. The bulk phase aluminum-doped cobaltosic oxide product prepared by using the method has an aluminum doping amount of 0.5-1%, comprisesthe aluminum element which is uniformly distributed, has laser granularity of 15-20mu m, a tap density greater than or equal to 2.5g/cm<3>, a specific surface area of 1.0-3.0m<2>/g, and has a blockyor sphere-like morphology.

The invention discloses a nickel cobalt oxyhydroxide-doped graphene oxide composite catalyst, and preparation and application thereof. The transition metal oxyhydroxide-doped graphene oxide compositecatalyst comprises graphene oxide and Ni<x>Co<1-x>OOH, wherein x is in a range of 0.5 to 0.9. The Ni-Co transition metal oxyhydroxide-doped graphene oxide shows superior oxidizability, photoelectrochemical properties and electrocatalytic activity due to its special structure, high specific surface area and high activity.

The invention discloses a preparation method of niobium, tungsten and tantalum-doped cobalt trioxide and belongs to the technical field of lithium ion batteries. The preparation method is characterized in that the synthetic reaction is performed by taking a certain concentration of cobalt solution as a cobalt source, a sodium hydroxide solution as a precipitating agent, an ammonia aqueous solutionas a complexing agent, a hydrazine hydrate solution as a reducing agent and a niobium, tungsten and tantalum chloride anhydrous alcohol solution as a doping agent; in the reaction process, the niobium, tungsten and tantalum chloride anhydrous alcohol solution is added in a reaction kettle in a dispersive liquid adding manner to participate in the reaction; after the end of the synthetic reaction,a synthetic product is oxidized into hydroxyl cobalt oxide by utilizing a hydrogen peroxide solution under the condition of a certain pH value, and then a mixture is washed, dried and calcined to obtain a niobium, tungsten and tantalum-doped cobalt trioxide product with uniformly-distributed doped elements; the production efficiency is high. The niobium, tungsten and tantalum-doped cobalt trioxide product prepared by the preparation method disclosed by the invention has a doping amount of 0.5-1 percent, has the uniformly-distributed doped elements, has a laser particle size of 15-20 mum, a tap density of more than or equal to 2.5 g/cm<3> and a specific surface area of 1.0-3.0 m<2>/g and has a massive or nearly-spherical appearance.

The present invention provides alkaline storage batteries high in energy density and excellent in overdischarge resistance, and, besides, less in decrease of capacity even if charging and discharging cycle is repeated at high temperatures. There is used a positive electrode comprising a foamed nickel substrate having the number of pores of 80-160 pores/inch (PPI2D) and a thickness of skeleton of 30-60 mum in which spherical nickel hydroxide solid solution particles having an average particle size of 5-20 mum and a cobalt oxide conductive agent having an average particle size of 1 mum or less and mainly composed of gamma-cobalt oxyhydroxide having a cobalt valence of higher than 3.0 are held and the total occupying ratio of the spherical nickel hydroxide solid solution particles and the cobalt oxide conductive agent based on the whole electrode plate is in the range of 75-85 vol %.

This invention discloses an electrochemical device having a multilayer structure and methods for making such a device. Specifically, this invention discloses a multilayer electrochemical device having nano-sized cobalt oxyhydroxide conductive agents and/or active materials within the polymer layers.