764results about "Nickel oxides/hydroxides" patented technology

The invention provides a method for precipitating nickel and cobalt in a solution containing nickel and cobalt and a cobalt nickel hydroxide product. The method comprises the following steps: step S100, carrying out a seed crystal pretreatment reaction on a nickel-cobalt-containing solution by adopting first nickel-cobalt precipitation underflow to form pretreated nickel-cobalt ore pulp; step S200, adding an alkaline precipitation inducer into the second nickel-cobalt precipitation underflow or the first nickel-cobalt precipitation overflow to carry out alkali conversion reaction to form alkali conversion crystal mush; s300, the pretreated nickel-cobalt ore pulp and alkali conversion crystal mush are continuously introduced into a reactor for a nickel-cobalt precipitation reaction, and nickel-cobalt precipitated ore pulp is obtained; step S400, continuously performing dense separation treatment on the ore pulp subjected to nickel-cobalt precipitation; s500, the third nickel-cobalt precipitation underflow is filtered and washed in sequence, a nickel-cobalt hydroxide product is obtained, and the problems that in the prior art, when nickel and cobalt are precipitated through a nickel-cobalt-containing solution, MHP is small in particle size and not prone to sedimentation, the water content of a filter cake is high, or the precipitation rate is poor, and the magnesium content is high before technical improvement are solved.

The present invention relates to a positive electrode active material, and to a positive electrode active material including a lithium transition metal composite oxide in a form of a single particle which contains nickel, cobalt, and manganese, wherein the lithium transition metal composite oxide contains 60 mol% or more of the nickel among total transition metals and has a D50 of 5 µm or more, and a positive electrode and a lithium secondary battery which include the same.

The invention discloses a method for recovering lithium, nickel cobalt manganese composite hydroxide and aluminum copper powder from a waste ternary lithium ion battery pole piece. The method comprises the following steps: treating waste pole pieces of a ternary plant or a mixture of positive and negative pole pieces by using a Fenton technology, leaching by using a mixed ferric salt solution, and filtering to obtain lithium-containing leachate and slag; adjusting the pH value of the leachate, oxidizing and filtering to obtain a purified solution and ferric hydroxide precipitate, and adding the purified solution and a lithium hydroxide solution into a reactor for coprecipitation to obtain a deeply purified solution and the nickel-cobalt-manganese composite hydroxide. And dissolving the ferric hydroxide precipitate with dilute acid, adding a reducing agent to generate a ferrous salt solution, and returning the ferrous salt solution for Fenton reaction and leaching reaction. And adding the sodium carbonate saturated solution into the deep purification solution, and crystallizing and precipitating to obtain the battery-grade lithium carbonate. And performing hydrodynamic screening on the leaching residues to obtain an aluminum-copper mixture and graphite residues, and performing grinding and specific gravity separation on the aluminum-copper mixture to obtain high-purity aluminum powder and copper powder. According to the method, the iron salt is directly leached from the pole piece, the used iron salt can be recycled, and the method is suitable for large-scale recovery of the waste ternary lithium ion battery.

The present disclosure discloses a multilayer annular pore nickel-cobalt-aluminum precursor and a preparation method and a positive electrode material thereof. The precursor D50 is 8 to 20 μm. It may be seen from a section diagram that there is a plurality of layers of annular pores in a secondary spherical particle structure, and a average porosity value of the section with a single particle or a plurality of particles is 6% to 14%. A co-precipitation reaction of nickel-cobalt mixed salt solution, alkali-aluminum solution, a complexing agent, and a precipitating agent is performed, a pH value and a concentration of aluminum solution at each stage are strictly controlled, and then working procedures of solid-liquid separating, washing, drying, mixing, sieving, and demagnetizing are performed to obtain the multilayer annular pore nickel-cobalt-aluminum precursor.

The invention relates to a low-temperature graphite negative electrode material and a preparation method thereof, and belongs to the technical field of high polymer materials. According to the prepared low-temperature graphite negative electrode material, firstly, the surface of graphite is pre-oxidized through potassium persulfate, phosphorus pentoxide and concentrated sulfuric acid, and then under the action of sodium nitrate, potassium permanganate and hydrogen peroxide, graphite oxide is prepared; then, ammonium molybdate hydrate and thioacetamide are used as a molybdenum source and a sulfur source, graphite oxide is used as a supporting material, a molybdenum disulfide-graphite compound is synthesized, and the conductivity and the cycling stability are improved; secondly, the surface of the negative electrode is coated with amorphous resin carbon / nickel oxide, so that the ion diffusion efficiency of the low-temperature graphite negative electrode material is enhanced, and the electrochemical lithium storage performance is improved in a low-temperature environment; and finally, the surface of the amorphous resin carbon / nickel oxide is coated with a layer of polythiophene film, so that the rate capability of the negative electrode material is improved due to large surface area and high pores.

A method of forming a cathode material precursor is provided. The method is an ethanol-assisted, hydrothermal synthesis and includes dissolving a nickel nitrate hydrate in ethanol to obtain a first mixture. The first mixture is then heated at a first temperature for a first period of time. Subsequently, the first mixture is cooled, filtered, washed, and dried to obtain a nickel hydroxide hydrate precipitate that is the cathode material precursor. In the method, the first mixture is free of ammonia. The cathode material precursor obtained may be α-3Ni(OH)2·2H2O. A method of forming a cobalt-free, nickel-rich cathode material from the cathode material precursor is also provided. The resulting cathode material may be LiNi0.9Mn0.05Al0.05 O2 (NMA9055).

The invention relates to an electrolytic fluorine-making nickel-containing waste electrolyte treatment method which comprises the following steps: heating a fluorine-making electrolytic cell to 80-95 DEG C, completely melting the electrolyte, standing for layering, and taking out the colorless electrolyte on the upper layer; excessive fluorine gas is introduced into the electrolytic cell, and ferrous ions in the remaining electrolyte are converted into iron ions; electrolyte in the electrolytic bath is guided into an anti-corrosion container, deionized water is added into the anti-corrosion container, and the electrolyte is completely dissolved; adjusting the pH value of the solution in the container to 3-4, fully precipitating, and carrying out solid-liquid separation to obtain a solid A and a filtrate A; adjusting the pH value of the filtrate A to 9-11, fully precipitating, and carrying out solid-liquid separation to obtain a solid B and a filtrate B; and adjusting the ion molar ratio of F <-> to K < + > in the filtrate B to be 2: 1, then carrying out evaporative crystallization, and drying obtained crystals to obtain products of potassium hydrogen difluoride and potassium fluoride. The waste electrolyte can be effectively treated, and resources are efficiently recycled and reutilized.

The invention discloses a carbon-material-doped titanium-based tin-antimony-nickel composite coating electrode and a preparation method and application thereof.The specific process includes the steps that a titanium sheet is pretreated, the treated titanium sheet is placed in electro-deposition liquid to be subjected to constant-temperature pulse electro-deposition, the titanium sheet is dried through a drying oven and then roasted in a muffle furnace, and a carbon-material-doped middle layer is obtained; and then the carbon material doped titanium-based tin-antimony-nickel composite coating electrode is obtained through cyclic thermal oxidation and quenching processes. According to the preparation scheme provided by the invention, the electrode surface is thick and rough, has a large number of defects and is excellent in electrocatalytic activity. Compared with a single coating, the composite coating has longer service life and higher ozone generation efficiency in the application of preparing ozone by electrolyzing water.

The invention discloses a lithium iron manganese phosphate positive electrode material and a preparation method thereof, and belongs to the technical field of lithium ion batteries, the lithium iron manganese phosphate positive electrode material at least comprises lithium iron manganese phosphate particles and a coating layer coating the lithium iron manganese phosphate particles; the raw material of the coating layer comprises an aluminum fluoride embedded poly (ethylenedioxythiophene)-lithium polystyrene sulfonate compound. And the coating layer can be used as a physical barrier to form dynamic interface protection, so that dissolution of manganese and erosion of electrolyte are directly inhibited, and side reaction between the electrolyte and the positive electrode material is reduced. Meanwhile, a more flexible transmission channel is provided for lithium ions and electrons, the conductivity of the positive electrode material is enhanced while the transmission efficiency of the lithium ions is improved, and the lithium manganese iron phosphate positive electrode material with stable structure, high rate capability and cycling stability is obtained.

The invention relates to a method and a system for preparing a battery metal oxide precursor through nitrate spray pyrolysis. The method comprises the following steps: preparing a metal nitrate mixed solution; atomizing and spraying the metal nitrate mixed solution into a reaction furnace, and performing pyrolysis through different heating temperature zones in the reaction furnace to obtain a metal oxide mixture and high-temperature flue gas; the high-temperature flue gas is subjected to waste heat recovery treatment and then enters a regeneration device to be recovered, and regenerated nitric acid is obtained; the metal oxide mixture is subjected to secondary heating at the bottom of the reaction furnace. The metal oxide precursor is prepared through spray pyrolysis, and compared with a traditional coprecipitation calcination process, the method is more economical and lower in operation cost; and different heating temperature zones are adopted for pyrolysis, so that the application range is wider, and the device can be suitable for metal nitrate at different pyrolysis temperatures.

The invention relates to the technical field of wave-absorbing materials, in particular to a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material. The invention provides a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material, which comprises the following steps of: etching titanium aluminum carbide powder through a LiF / HCl mixture, and performing ultrasonic stripping to prepare a uniform dispersion of MXene nanosheets; the preparation method comprises the following steps: dispersing MXene nanosheets in a solution of water and absolute ethyl alcohol, and adding a pyrrole monomer and a FeCl3. 6H2O aqueous solution for reaction; after the reaction, washing is performed to obtain a PPy-MXene composite material; the preparation method comprises the following steps: by taking NiCl2. 6H2O as a nickel source and sodium oxalate as a precipitator, preparing NiO nanowires by adopting a hydrothermal method combined with a calcining process; the invention discloses a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material.According to the method, the MXene-NiO-PPy ternary composite wave-absorbing material with rich heterogeneous interfaces and a porous micro-nano structure is constructed, cooperation of dielectric loss, magnetic loss and interface polarization loss is achieved, and finally the light, efficient and broadband wave-absorbing performance is obtained.

The invention discloses a rare earth element doped hydrogen evolution electrocatalyst and a preparation method and application thereof. The rare earth element doped hydrogen evolution electrocatalyst comprises rare earth element doped nickel oxide serving as a carrier and ruthenium atoms anchored on the carrier. According to the rare earth element-doped hydrogen evolution electrocatalyst provided by the invention, the adsorption of hydroxyl is enhanced by doping the oxyphilic rare earth element with NiO, the hydrogen conversion on the surface of Ru is promoted by a rare earth element / NiO carrier, and the rare earth element / NiO and Ru generate a definite synergistic effect to jointly promote the dissociation of water, so that the rare earth element-doped hydrogen evolution electrocatalyst shows very high catalytic activity in alkaline HER; a new thought is provided for accelerating alkaline HER reaction kinetics. In an alkaline HER test, the rare earth element doped hydrogen evolution electrocatalyst provided by the invention can reach the current density of 10mA cm <-2 > by only needing the overpotential of 38mV; and after a stability test is carried out for 50 hours, the overpotential is not attenuated.

The invention provides a graphene-based hydrogen sulfide gas sensor and a preparation method thereof, and relates to the technical field of gas sensors. The preparation method of the graphene-based hydrogen sulfide gas sensor comprises the following steps: soaking the wood substrate in a mixed metal salt solution containing a water-soluble silver salt and a water-soluble transition metal salt; irradiating the soaked wood substrate by using a laser beam at room temperature under the condition of no shielding gas, so that lignin and cellulose in the wood substrate are cracked and reconstructed to form graphene; meanwhile, the mixed metal salt immersed in the wood substrate is decomposed to form bimetallic oxide nanoparticles including silver oxide nanoparticles and transition metal oxide nanoparticles, and the bimetallic oxide nanoparticles are dispersed on the surface of each layer of graphene to obtain a sensitive layer; and coating conductive materials on the wooden substrate and on the two sides of the sensitive layer to form a connecting electrode in contact with the sensitive layer, thereby obtaining the graphene-based hydrogen sulfide gas sensor.

The invention belongs to the technical field of nano material heterojunctions, and particularly relates to a NiO / Ag / ZnIn2S4 heterojunction nanosheet array, a preparation method thereof and a room temperature gas sensor. The device comprises a substrate and a NiO / Ag / ZnIn2S4 heterojunction nanosheet array which grows on the surface of the substrate in situ, the NiO / Ag / ZnIn2S4 heterojunction nanosheet array is composed of NiO porous nanosheets, Ag nanoparticles and ZnIn2S4 nanosheets, the NiO nanosheets are of an array structure growing vertically in a staggered mode, the Ag nanoparticles are evenly dispersed on the surfaces of the NiO porous nanosheets, and the ZnIn2S4 nanosheets wrap the NiO porous nanosheets. The preparation process is simple, the cost is low, the NiO / Ag / ZnIn2S4 heterojunction nanosheet array has good heterogeneous interface contact, electron transfer between NiO and ZnIn2S4 is promoted due to existence of Ag nanoparticles, and the specific surface area of the material is increased due to wrapping of ZnIn2S4. The NiO / Ag / ZnIn2S4 heterojunction nanosheet array can be applied to a room-temperature gas sensor, and specifically, room-temperature high-selectivity detection of triethylamine under excitation of white light can be realized.

Provided are a cathode active material having a suitable particle size and high uniformity, and a nickel composite hydroxide as a precursor of the cathode active material. When obtaining nickel composite hydroxide by a crystallization reaction, nucleation is performed by controlling a nucleation aqueous solution that includes a metal compound, which includes nickel, and an ammonium ion donor so that the pH value at a standard solution temperature of 25° C. becomes 12.0 to 14.0, after which, particles are grown by controlling a particle growth aqueous solution that includes the formed nuclei so that the pH value at a standard solution temperature of 25° C. becomes 10.5 to 12.0, and so that the pH value is lower than the pH value during nucleation. The crystallization reaction is performed in a non-oxidizing atmosphere at least in a range after the processing time exceeds at least 40% of the total time of the particle growth process from the start of the particle growth process where the oxygen concentration is 1 volume % or less, and with controlling an agitation power requirement per unit volume into a range of 0.5 kW / m3 to 4 kW / m3 at least during the nucleation process.

A positive electrode active material includes a layered lithium nickel-based composite oxide, wherein, based on 100 mol% of a total mole of metals of the layered lithium nickel-based composite oxide excluding lithium, a nickel content is greater than or equal to about 60 mol%, an aluminium content is about 0.8 mol% to about 1.5 mol%, a zirconium content is about 0.1 mol% to about 0.3 mol%, a ratio of the aluminium content relative to the zirconium content (AI / Zr) is greater than or equal to about 5, and the positive electrode active material is in a form of a single particle with an average particle diameter (D50) of about 1 µm to about 4 µm. Also disclosed are a positive electrode comprising a positive electrode current collector having a layer of said positive electrode active material located thereon, and a rechargeable lithium battery comprising said positive electrode, a negative electrode and an electrolyte. Further disclosed is a method of preparing the positive electrode active material.

The present exemplary embodiments relate to a positive electrode active material, its manufacturing method, and a lithium secondary battery including the same. The positive electrode active material according to an exemplary embodiment is a metal oxide particle including:a metal oxide particle comprising a central portion and a surface portion located on the surface of the central portion, wherein, the metal oxide particle includes nickel, cobalt, manganese, and doping elements and is composed of a single particle, and the metal oxide particle includes a crystal phase of layered structure belonging to the R-3m space group on the surface, and an average grain size is 1550 Å or more.

The present application belongs to the field of new energy, and discloses a waste lithium ion battery crushing, sorting, and recycling method, comprising the following steps: step 1, crushing a lithium ion battery and heating, to obtain a first solid; step 2, removing a housing, to obtain a second solid; step 3, sieving the second solid, to obtain a first undersize product and a first oversize product; step 4, performing airflow sorting on the first oversize product to remove a separator, to obtain a third solid; step 5, pyrolyzing the first undersize product and the third solid, to obtain a fourth solid; step 6, sieving the fourth solid, to obtain a second undersize product and a second oversize product; and step 7, crushing and sieving the second oversize product, to obtain a third undersize product and a third oversize product. By means of collecting black powder before and after crushing in step 7, the present method implements black powder grading, thereby facilitating targeted treatment of black powder of different grades. The black powder recovery rate and the collection efficiency of the present application are high, and a separator is efficiently removed. Furthermore, the present application also discloses a system suitable for said method.

The invention provides spherical nickel hydroxide as well as a preparation method and application thereof, and relates to the technical field of lithium ion battery precursors. The spherical nickel hydroxide comprises secondary particles; the secondary particles are formed by stacking primary particles on the surface of the crystal nucleus, the primary particles are spindle-shaped, the average length of the primary particles is 600-900 nm, and the average width of the primary particles is 150-250 nm. By limiting the morphology and size of the primary particles, both the energy density and the lithium ion transmission efficiency can be improved.

The invention provides a method for recovering valuable elements from slurry bed catalyst discharged oil residues, and relates to the technical field of solid waste treatment. The method comprises the following steps: sequentially carrying out medium-temperature oxidizing roasting and high-temperature reduction cracking on slurry bed catalyst discharged oil residues to obtain cracking residues; the cracking residues and an alkaline oxidation leaching agent are mixed for leaching, and nickel-containing leaching residues and molybdenum and vanadium-containing leaching liquid are obtained; the leachate containing molybdenum and vanadium is mixed with ammonium salt for vanadium precipitation, and an ammonium metavanadate product and vanadium precipitation tail liquid are obtained; the vanadium precipitation tail liquid and an acid reagent are mixed for neutralization molybdenum precipitation, and crude molybdic acid is obtained; the crude molybdic acid is sequentially subjected to calcination, alkali dissolution, ion exchange impurity removal and neutralization, and a molybdic acid product is obtained. According to the method, the leaching rates of molybdenum, vanadium and nickel can be greatly increased, comprehensive recovery of valuable elements is achieved, the comprehensive recovery rates of molybdenum, vanadium and nickel in the whole process are all larger than 99%, and the product purity is high and meets the quality requirements of corresponding standards.

The present invention discloses a silicon-carbon negative electrode material modified with a magnetic transition metal oxide and a preparation method thereof, and belongs to the technical field of lithium-ion battery micro-nano materials. The preparation method provided by the present invention has readily available raw materials, low prices, a simple preparation process flow, easy operation, low energy consumption, and environmental friendliness in the preparation process. The prepared silicon-carbon negative electrode material has a uniform and dense modified layer containing a magnetic transition metal oxide, which can effectively improve the conductivity, high specific capacity, and cycle stability of the silicon-carbon negative electrode material. The first coulomb efficiency reaches more than 80%, and the specific capacity can be stabilized to a maximum of 1127mAh / g after 100 cycles, which is much higher than the current average level of this type of material. In addition, the prepared silicon-carbon negative electrode material has excellent mechanical flexibility and can be directly used in the assembly of lithium-ion batteries, and has strong application potential in flexible wearable electronic devices in the future.

The invention discloses a nickel-vanadium oxide catalyst, a preparation method thereof and a method for preparing propylene by catalyzing oxidative dehydrogenation of propane. The invention aims to provide the preparation method of the nickel-vanadium oxide catalyst, and the nickel-vanadium oxide catalyst has relatively high selectivity for catalyzing oxidative dehydrogenation of propane to prepare propylene under a low-temperature condition. The technical scheme is as follows: (1) preparing a vanadium trichloride aqueous solution; (2) adding nickel chloride hexahydrate and urea into the vanadium trichloride aqueous solution, and stirring for 1 hour at normal temperature; (3) putting the obtained solution into a reaction kettle for hydrothermal reaction; (4) centrifuging, washing with deionized water, and drying in vacuum to obtain a solid product; and (5) calcining the solid product at 600 DEG C for 4 hours to obtain a finished product. Belongs to the technical field of thermocatalytic materials and environmental protection.

A particulate nanocomposite material comprising, as determined by X-ray diffraction (XRD): elemental carbon (C); elemental nickel (Ni) in a cubic crystalline phase; a cubic nickel oxide (NiO) crystalline phase; an orthorhombic calcium borate (CaB2O4) crystalline phase; and, a magnesium borate (MgB2O4) crystalline phase. The porous particulate nanocomposite is characterized in that, based on the total number of atoms in the particulate nanocomposite material: the atomic concentration of carbon is from about 1 atomic percent (at. %) to about 10 at. %; the atomic concentration of nickel is from about 1 at. % to about 10 at. %; the atomic concentration of boron (B) is from about 1 at. % to about 10 at. %; the atomic concentration of magnesium (Mg) is from about 5 at. % to about 15 at. %; and, the atomic concentration of calcium (Ca) is from about 1 at. % to about 10 at. %.

The invention provides a method for improving main components in a cobalt nickel hydroxide intermediate product. The lifting method comprises the following steps: step S100, carrying out first activation on cobalt nickel hydroxide intermediate product slurry by adopting an alkaline substance to obtain first activated product slurry; step S200, adjusting the solid content of the first activated product slurry; s300, activating the first activated product slurry for the second time by adopting a reducing agent to obtain second activated product slurry; step S400, adjusting the solid content of the second activated product slurry; and step S500, adding the second activated product slurry into a nickel-cobalt-containing solution for conversion reaction to obtain nickel cobalt hydroxide and a converted solution. According to the method disclosed by the invention, the total content of nickel and cobalt in cobalt nickel hydroxide can be remarkably increased and reaches a level exceeding 50%. The problems that the content of impurities such as magnesium and manganese in the nickel cobalt hydroxide intermediate product is too high, the content of sulfate radicals is too high, and consequently the subsequent refining production cost is increased are solved.

The invention provides chlorine-doped nickel oxide, a preparation method and application thereof and a photoelectric device, and relates to the field of photoelectric materials.The preparation method of the chlorine-doped nickel oxide comprises the following steps that S10, an aqueous solution of nickel salt and chlorine salt is obtained, an alkaline solution is dropwise added, centrifugation is conducted, and a coprecipitate is obtained; s20, washing, drying and roasting the coprecipitate to obtain chlorine-doped nickel oxide; wherein the molar ratio of the nickel salt to the chlorine salt is (10-20): (1-4). In the technical scheme provided by the invention, the nickel salt and the chlorine salt are co-precipitated to generate a co-precipitate of nickel hydroxide and chloride, and then the co-precipitate is washed, dried and roasted to prepare the chlorine-doped nickel oxide, so that the hole mobility of the chlorine-doped nickel oxide is improved; the alkaline solution is dropwise added for coprecipitation, so that the particle size of the coprecipitate can be reduced, and the nanoscale chlorine-doped nickel oxide is prepared, so that the dispersity of the chlorine-doped nickel oxide in a mobile phase is improved, and the chlorine-doped nickel oxide can be applied to preparation of a hole transport film and improvement of the uniformity of the hole transport film.

A process for the production of a mixed metal hydroxide material for use as a cathode active material precursor is described, wherein the process utilizes cavitation to produce high quality materials through elimination of some processing steps and ingredients. In particular, a method of producing a mixed metal hydroxide material combining a first metal, a second metal, an oxidant and a liquid to form a reaction slurry is disclosed. The method may include applying cavitation to the liquid prior to the formation of the reaction slurry and / or applying cavitation to the liquid when the liquid is part of the reaction slurry. A method of forming an active material and a mixed metal hydroxide material for use as an active material precursor is also disclosed.

The invention discloses a nickel-manganese binary precursor material with a multilayer core-shell structure as well as a preparation method and application of the nickel-manganese binary precursor material. The core-shell structure of the precursor material comprises an inner core, shell layers, middle layers and an outermost layer from inside to outside, the shell layers and the middle layers are alternately distributed, and the secondary outer layer is the shell layer; wherein the inner core structure is loose, and the shell structure is compact; the middle layer and the outermost layer are the same in structure and are both loose and porous needle-shaped structures. According to the invention, a coprecipitation method is used, and a multi-layer core-shell structure with alternated density and density is formed by different processes in stages during synthesis. The material can effectively solve the problem that a common core-shell structure material is prone to structural stripping and collapse under the high-voltage condition, the stability of the material is improved, the ion transmission efficiency is improved, and the battery capacity and the service life are guaranteed.

The present invention relates to a positive electrode active material, and a positive electrode and a lithium secondary battery comprising the same, and relates to a positive electrode active material comprising a lithium transition metal composite oxide in a single particle form, the lithium transition metal composite oxide in the single particle form containing nickel, cobalt and manganese, the lithium transition metal composite oxide contains 60 mol% or more of nickel with respect to the total transition metal, and has a D50 of 5 [mu] m or more.

The present disclosure relates to methods for recovering metals from used lithium-ion batteries and related electronic wastes. The methods provide modular, inexpensive, and energy efficient means for recovering up to 99.9% pure lithium, nickel, cobalt, and manganese in the form of various oxides or salts, e.g., phosphates, sulfates, or hydroxides. The methods produce nearly zero waste, as many of the recovered waste products can be purified and / or recycled.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a composite positive electrode material for a lithium ion battery and a preparation method of the composite positive electrode material. The composite positive electrode material is composed of a positive electrode base material, a lithium supplementing material and a catalytic material. The preparation method comprises the following steps: (1) preparing a composite material of the positive electrode base material and the lithium supplementing material in situ; and (2) dispersing the catalytic material on the surface of the composite material of the positive electrode base material and the lithium supplementing material, and forming a stable interface layer between the catalytic material and the lithium supplementing material. According to the method disclosed by the invention, the lithium supplementing material has double functions of surface modification of a positive electrode base material and lithium supplementing of a negative electrode, and meanwhile, the first effect and the cycling stability of the battery are improved; a catalytic material is introduced to the surface of the lithium supplementing material, free O generated by the lithium supplementing material Li is fixed in situ, the bag expansion phenomenon of the battery is relieved, and the cycling stability and safety of the battery are further improved; the preparation process is simple, raw materials are cheap and easy to obtain, the production cost is low, and industrial production and popularization are easy.