Preparation method of liquid-phase microemulsion medium coated ternary positive electrode material

Abstract

The invention relates to a preparation method of a liquid-phase microemulsion medium coated ternary positive electrode material, which comprises the following steps of: 1, fully mixing a ternary precursor material with a lithium source to form a mixed material; step 2, putting the mixed material into a sagger, and fully sintering to form a ternary positive electrode material; 3, performing coarse crushing and crushing on the ternary positive electrode material, and sieving to form a treated ternary positive electrode material; step 4, adding the solution into a reaction kettle; adding an emulsifier, continuously stirring in the adding process, and accelerating stirring after pre-stirring to form a microemulsion; step 5, adding the treated ternary positive electrode material and the coating additive into the reaction kettle; after stirring, micro-emulsion containing the coated ternary positive electrode material is added into a closed filter press; and step 6, adding the filter-pressed ternary positive electrode material into a measuring bin of a roller kiln, loading the filter-pressed ternary positive electrode material into a sagger for cladding and sintering, and packaging after sieving and demagnetizing. The problems that in an existing scheme, coating uniformity is poor, and the surface of the positive electrode material is exposed much are solved.

Description

Technical Field

[0001] The invention relates to the field of battery materials, and in particular to a method for preparing a liquid microemulsion medium coated ternary positive electrode material. Background Art

[0002] There are several problems with high-nickel and ultra-high-nickel ternary positive electrode materials: 1. Generation of residual lithium compounds: During sintering, excess lithium will react with oxygen, carbon dioxide, etc. to form residual lithium compounds on the surface; the highly active Ni3+ in the high-nickel ternary positive electrode material will be enriched on the surface of the positive electrode material, causing lattice oxygen to precipitate from the inside and react with surface lithium to form residual lithium compounds. 2. Cation mixing: During the battery charge and discharge cycle, the mixing of lithium ions and transition metal ions in the nickel-rich layered positive electrode will hinder the migration of lithium ions. 3. Surface side reactions: Residual lithium compounds on the surface of nickel-rich positive electrode materials will react with the electrolyte, bringing the risk of gas release; the contact between the surface of the positive electrode material and the electrolyte will cause surface reorganization and phase change, resulting in obstructed lithium ion diffusion and serious interface side reactions, affecting the performance of the battery. 4. Intracrystalline and intercrystalline cracks and impaired mechanical integrity: lattice collapse, phase change, cation mixing, lattice oxygen loss, surface reconstruction and uneven lithiation / delithiation can all lead to cracks, resulting in poor charge and discharge cycle performance of the positive electrode material. 5. Poor thermal stability: The increase in nickel content causes serious lithium-nickel mixing and more oxygen vacancies, leading to structural changes.

[0003] By adding oxidants during sintering, the overoxidation of high-nickel and ultra-high-nickel positive electrode materials can be achieved, which can effectively reduce the phase change during the synthesis process. The polycrystalline ternary positive electrode material can also be sintered into a single-crystal positive electrode material with the corresponding nickel content to reduce the grain boundary stress. Due to the high crystallinity and equidirectionality of the single-crystal positive electrode material, higher mechanical strength can be achieved, thereby showing better cycle performance at the battery end. Doping or coating additives can improve the various properties of NCM. Electrochemically inert ions can replace unstable nickel ions, thereby reducing the degree of mixing between Ni and Li, inhibiting the irreversible phase change during the lithium removal process and the phase change during the cycle. Ion doping is divided into cation doping and anion doping. Anion doping is a doping that stabilizes the structure by replacing oxygen ions in the NCM ternary positive electrode material to form a stronger chemical bond with the transition metal ion. Surface coating modification is usually achieved by physical or chemical methods to attach a "protective layer" to the surface of the high-nickel ternary positive electrode material particles, and combined with the subsequent heat treatment process to make the protective layer more closely bonded to the electrode material. The presence of the protective layer can effectively prevent the direct contact between the electrode material and the electrolyte, reduce the corrosion of HF on the electrode material, and effectively reduce the occurrence of interfacial side reactions; at the same time, the protective layer will also react with the alkaline substances remaining on the surface of the high-nickel ternary positive electrode material during the formation process, reducing the alkaline residue on the surface of the electrode material; the electrochemically active protective layer can also greatly improve the interfacial transfer impedance of the electrode material.

[0004] Coating is an important method for surface modification of high-nickel ternary cathode materials. Coating materials can not only protect the surface of materials and improve the structural stability of materials, but also improve the transmission capacity of ions or electrons and the electrochemical performance of materials. Traditional methods cannot achieve the formation of a thin and uniform coating layer under ideal conditions.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a preparation method for liquid microemulsion medium coated ternary positive electrode material to solve the problems of poor coating uniformity and excessive exposure of the positive electrode material surface in the prior art.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] A method for preparing a ternary positive electrode material coated with a liquid microemulsion medium;

[0009] The following methods are included:

[0010] Step 1, fully mixing the ternary precursor material and the lithium source to form a mixed material;

[0011] Step 2: Place the mixed material into a sagger and use a roller kiln to fully sinter it to form a ternary positive electrode material;

[0012] Step 3, the ternary positive electrode material is coarsely broken and crushed and then sieved to form a processed ternary positive electrode material;

[0013] Step 4, adding the solution to the reaction kettle; adding the emulsifier, stirring continuously during the addition process, the speed is 500-800 rpm / min, and after pre-stirring for 5 minutes, the stirring is accelerated and the speed is increased to 1500-2000 rpm / min until the solution becomes milky white and can maintain the milky state without stratification, so as to form a microemulsion;

[0014] Step 5, adding the treated ternary cathode material and the coating additive into the reactor; adding the microemulsion containing the coated ternary cathode material into the closed filter press after stirring; the moisture content of the ternary cathode material after filtration is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor;

[0015] Step 6: After the filtration, the ternary positive electrode material is added to the metering bin of the roller kiln, and then loaded into the sagger for coating and sintering. The sintering temperature is 300-800° C. and the sintering time is 4-11 hours. The sintered material is sieved and demagnetized before packaging.

[0016] A further technical solution is that in step 1: the chemical formula of the ternary precursor material is Ni a Co b Mn (1-a-b) (OH) 2 (a+b+c=1); the molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:(1.01-1.08); the purity of the lithium source is greater than 98%; the lithium source is battery-grade lithium carbonate, battery-grade lithium bicarbonate, battery-grade lithium hydroxide, industrial-grade lithium carbonate, industrial-grade lithium bicarbonate, industrial-grade lithium hydroxide, lithium nitrate, lithium sulfate, lithium chloride or lithium fluoride; the ternary precursor material and the lithium source are mixed using a planetary ball mill, a high-speed mixer or a plowshare mixer.

[0017] A further technical solution is that in step 2: the sintering temperature is 700-1000°C, and the sintering time is 10-15h; the sintering heating rate is 1°C / min, 2°C / min, 3°C / min, 4°C / min or 5°C / min; the sagger material is corundum or mullite.

[0018] A further technical solution is that in step 3: after the ternary positive electrode material is naturally cooled to 70-100°C, it is coarsely broken and crushed and then sieved; the coarse breaking is carried out using a jaw crusher and a double-roller mill, and the double-roller mill is single-layer or double-layer; the crushing is carried out using a powder mill, a jet mill or a mechanical mill; the mesh number of the sieve is 200-400 mesh.

[0019] A further technical solution is that in step 4: the solution concentration is 80% to 90%; the solution is one of ethanol solution, methanol solution, acetone solution, methyl ether solution, and dimethyl ether solution; the emulsifier is one of Span 60, Tween 60, Span 80, Tween 80 aminocarboxylate, aminosulfate, phosphate, sodium allyl sulfonate, reactive emulsifier COPS1, allyloxy nonylphenoxy propanol polyoxyethylene ether ammonium sulfate, allyloxy nonylphenoxy propanol polyoxyethylene ether, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), sodium α-olefin sulfonate (AOS), SVS surfactant, (meth) acrylic acid polymerizable emulsifier, styrene polymerizable emulsifier, acrylamide polymerizable emulsifier, maleic acid polymerizable emulsifier, allyl polyether sulfonate, sodium allyl alkyl succinate sulfonate, and allyl alcohol polyoxyethylene ether series; the emulsifier accounts for 1% to 5% of the solution.

[0020] A further technical solution is that in step 4: adding the ethanol solution into the reaction kettle; adding Span80 and Tween80 as emulsifiers to ensure that the molar concentration after adding the ethanol solution is 2%.

[0021] A further technical solution is that in step 5: the type of the coating additive is a nano-scale metal oxide, a nano-scale metal phosphate or a nano-scale ion conductive material; the nano-scale metal oxide is Al 2 O 3 、ZrO 2 、TiO 2 or WO 3 ; Nano-scale metal phosphate is AlPO 4 、MnPO 4 ; The nano-scale ion conductive material is LiAlO 2 , Li 2 TiO 3 .

[0022] A further technical solution is that in step 5: the treated ternary positive electrode material and the coating additive are added to the reactor, the addition ratio of the coating additive is 500-5000ppm, and the ratio of the treated ternary positive electrode material to the microemulsion is 1:1-3; after stirring, the microemulsion containing the coated ternary positive electrode material is added to a closed filter press; the stirring time is 3-60min, and the stirring speed is 800-2000rmp / min.

[0023] A further technical solution is that in step 5: after stirring, the microemulsion containing the coated ternary positive electrode material is added to a closed filter press; the closed filter press has a discharge port and a liquid receiving port for collecting the microemulsion, and the microemulsion is collected and refluxed into the reactor; an inert gas can be introduced into the closed filter press; the inert gas is nitrogen.

[0024] A further technical solution is that in step 6: the amount of the sagger filled is 3-6 kg.

[0025] Compared with the prior art, the beneficial technical effects of the present invention are as follows: (1) The present invention uses an oily liquid to add an emulsifier and then stir to form a large number of extremely small microspheres of microemulsions, the diameter of the dispersed droplets is between 5nm and 100nm, the system is transparent, the fluidity is good, and the centrifugal acceleration separation for 5 minutes does not separate, and the thermodynamic stability is excellent. The microemulsion in the present application will not evaporate easily like the traditional liquid phase coating medium-ethanol, and the medium can be collected and reused after filter pressing.

[0026] (2) After the first sintering, there are defects on the surface of the ternary positive electrode material or the particles are not round. The microemulsion used in this application promotes the growth of droplets in the microemulsion by adjusting the ratio and concentration of surfactants. When the positive electrode material is rapidly stirred in the reactor, the droplets of the microemulsion will modify the surface of the positive electrode material particles through surface forces, repair the defects and make the particle surface round and smooth.

[0027] (3) Due to the high activity of Ni3+ in high-nickel ternary positive electrode materials, the positive electrode material surface will be enriched, resulting in the precipitation of lattice oxygen from the inside and reaction with surface lithium to form residual lithium compounds. This application uses the surface functional groups of microemulsion droplets and the principle of like dissolves like to remove excess impurities and carbonate and hydroxide on the high-nickel ternary positive electrode; compared with removing excess impurities and carbonate and hydroxide on the surface by washing with water, the drying step is omitted.

[0028] (4) The microemulsion droplets of the present application are hydrophilic inside and lipophilic outside. The hydrophilic additive used in the coating can be completely isolated outside the oil phase liquid and coated on the surface of the positive electrode material with almost no loss. Through repeated friction between extremely small droplets, the coating additive can be evenly coated on the surface of the positive electrode material as much as possible, thereby solving the problem of uneven coating and reducing the DCR of the positive electrode material.

[0029] (5) After the high nickel polycrystalline ternary positive electrode material is sintered once, a water washing process is usually required, but the water washing process will cause surface damage to the single crystal material, resulting in capacity loss. The microemulsion droplets of the present application are of the oil-in-water type, and will not cause the lattice lithium inside the positive electrode material to precipitate, resulting in capacity loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The schematic diagram of the process flow of the present invention is shown.

[0031] Figure 2 A schematic diagram comparing the coating of the ternary positive electrode material of the present invention and the coating of the ternary positive electrode by the traditional process is shown.

[0032] Figure 3 The EDS graph after coating with the liquid microemulsion medium of the present invention is shown.

[0033] Figure 4 The figure shows the capacity and cycle comparison after the liquid phase microemulsion medium coating and non-microemulsion coating of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present invention clearer, the device proposed by the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings adopt a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated by the accompanying drawings of this specification are only used to match the content disclosed in the specification, so that people familiar with this technology can understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0035] Figure 1 The schematic diagram of the process flow of the present invention is shown. Figure 2 A schematic diagram comparing the coating of the ternary positive electrode material of the present invention and the coating of the ternary positive electrode by the traditional process is shown. Figure 3 The EDS graph after coating with the liquid microemulsion medium of the present invention is shown. Figure 4 The figure shows the capacity and cycle comparison of the present invention after the liquid phase microemulsion medium coating and non-microemulsion coating. Figure 1-Figure 4 As shown, the present invention discloses a method for preparing a liquid microemulsion medium coated ternary positive electrode material.

[0036] The preparation method of the liquid microemulsion medium coated ternary positive electrode material includes the following method:

[0037] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0038] In step 1: the chemical formula of the ternary precursor material is Ni a Cob Mn (1-a-b) (OH) 2 (a+b+c=1). The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:(1.01-1.08). The purity of the lithium source is greater than 98%. The lithium source is battery-grade lithium carbonate, battery-grade lithium bicarbonate, battery-grade lithium hydroxide, industrial-grade lithium carbonate, industrial-grade lithium bicarbonate, industrial-grade lithium hydroxide, lithium nitrate, lithium sulfate, lithium chloride or lithium fluoride. The ternary precursor material and the lithium source are mixed using a star ball mill, a high-speed mixer or a plowshare mixer.

[0039] Step 2: Place the mixed material into a sagger and use a roller kiln to fully sinter it to form a ternary positive electrode material.

[0040] In step 2: the sintering temperature is 700-1000°C, the sintering time is 10-15h; the sintering heating rate is 1°C / min, 2°C / min, 3°C / min, 4°C / min or 5°C / min; the sagger material is corundum or mullite.

[0041] Step 3: The ternary positive electrode material is coarsely broken and crushed and then sieved to form a processed ternary positive electrode material.

[0042] In step 3: after the ternary positive electrode material is naturally cooled to 70-100°C, it is coarsely broken and crushed before screening. The coarse breaking is carried out by a jaw crusher and a roller mill, and the roller mill is a single-layer or double-layer mill. The crushing is carried out by a powder mill, a jet mill or a mechanical mill. The mesh number of the sieve is 200-400 meshes.

[0043] Step 4: Add the solution to the reactor. Add the emulsifier and continue stirring during the addition process at a speed of 500-800 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500-2000 rpm / min until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0044] In step 4: the concentration of the solution is 80% to 99%. The solution is one of ethanol solution, methanol solution, acetone solution, methyl ether solution, and dimethyl ether solution; the emulsifier is one of Span 60, Tween 60, Span 80, Tween 80 aminocarboxylate, aminosulfate, phosphate, sodium allyl sulfonate, reactive emulsifier COPS1, allyloxy nonyl phenoxy propanol polyoxyethylene ether ammonium sulfate, allyloxy nonyl phenoxy propanol polyoxyethylene ether, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), sodium α-olefin sulfonate (AOS), SVS surfactant, (meth) acrylic polymerizable emulsifier, styrene polymerizable emulsifier, acrylamide polymerizable emulsifier, maleic acid polymerizable emulsifier, allyl polyether sulfonate, sodium allyl alkyl succinate sulfonate, and allyl alcohol polyoxyethylene ether series. The emulsifier accounts for 1% to 5% of the solution.

[0045] In step 4: add the ethanol solution into the reactor. Add Span80 and Tween80 as emulsifiers to ensure that the molar concentration after adding the ethanol solution is 2%.

[0046] If water is used as the medium for liquid phase coating, the surface structure of the ternary positive electrode material will be destroyed during rapid stirring, and the lithium inside the structure will precipitate from the inside of the lattice, resulting in capacity loss of the material. This application uses oily substances such as ethanol as coating media, uses surfactants / dispersants as emulsifiers, and uses the principle of oil-in-water microemulsion to add hydrophilic ternary positive electrode materials and coating additives to oily ethanol. After adding the emulsifier, high-speed rotation is used to mix them together, which can achieve a more uniform and dense coating, avoid water erosion and damage to the surface of the positive electrode material, and at the same time, the surface morphology of the ternary positive electrode material can be modified by high-speed rotation to make it more rounded and smooth.

[0047] Step 5: Add the treated ternary cathode material and the coating additive into the reactor. After stirring, add the microemulsion containing the coated ternary cathode material into a closed filter press. After filtration, the moisture content of the ternary cathode material is not higher than 1500 ppm. The microemulsion is collected and refluxed into the reactor.

[0048] In step 5: the type of coating additive is nano-scale metal oxide, nano-scale metal phosphate or nano-scale ion conductive material; the nano-scale metal oxide is Al 2 O 3 、ZrO 2 、TiO 2 or WO 3 ; Nano-scale metal phosphate is AlPO 4 、MnPO 4 ; The nano-scale ion conductive material is LiAlO 2 , Li2 TiO 3 .

[0049] In step 5: the treated ternary cathode material and the coating additive are added to the reactor, the coating additive is added in an amount of 500 to 5000 ppm, and the ratio of the treated ternary cathode material to the microemulsion is 1:1 to 3. After stirring, the microemulsion containing the coated ternary cathode material is added to a closed filter press. The stirring time is 3 to 60 minutes, and the stirring speed is 800 to 2000 rpm / min.

[0050] In step 5: after stirring, the microemulsion containing the coated ternary cathode material is added to a closed filter press. The closed filter press has a discharge port and a liquid receiving port for collecting the microemulsion, and the microemulsion is collected and refluxed into the reactor. The closed filter press can be fed with an inert gas. The inert gas is nitrogen.

[0051] Step 6: After the filtration, the ternary positive electrode material is added to the metering bin of the roller kiln, and then put into the sagger for coating and sintering. The sintering temperature is 300-800°C and the sintering time is 4-11 hours. The sintered material is sieved and demagnetized before packaging.

[0052] In step 6: the amount of the sagger is 3 to 6 kg.

[0053] The coating using the traditional dry method of ball milling, high-speed mixer, etc. requires a second calcination process to finally form a tightly bound coating layer. Even nano-level coating additives cannot achieve uniform coating. The present application adopts a liquid phase coating method to ensure uniform coating.

[0054] After using water as a coating medium, the coated ternary cathode material is usually separated from the medium by filtering, filter pressing or centrifugation, and then dried and sintered, which consumes a large amount of water. The present application uses ethanol as a coating medium. Due to the volatile nature of ethanol itself, a large amount of steam will be generated during the evaporation and separation of materials, causing danger and waste. The microemulsion medium used in the present invention can be reused and is green and environmentally friendly. After coating, the ternary cathode material and the microemulsion are input into a closed filter press. After filter pressing, the microemulsion is recycled and reused through a pipeline.

[0055] There is too much residual lithium on the surface of high-nickel positive electrode materials. Dry coating cannot eliminate a large amount of residual lithium on the surface of positive electrode materials. It can only neutralize with carbonate and hydroxide during high-temperature sintering through coating additives, but the residual lithium that can be reduced is limited. This application can remove the residual lithium on the surface during the liquid phase coating process, while eliminating the washing, filter pressing, and drying processes of ternary high-nickel polycrystalline positive electrode materials.

[0056] The present application is described below through a number of embodiments and comparative examples:

[0057] Embodiment 1:

[0058] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0059] In step 1: the ternary precursor material is Ni with a particle size of 10 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0060] Step 2: Place the mixed material into a corundum sagger, heat it to 750°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0061] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0062] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 2% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0063] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3 The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 5 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0064] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0065] Finally, 2% R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary positive electrode material, wherein R is the liquid coating medium which is a microemulsion, and 2% is the amount of emulsifier added.

[0066] 2% R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0067] like Figure 3 As shown in the figure, after the new liquid microemulsion medium is coated, the elements are evenly distributed, showing an excellent coating effect. Figure 4 As shown, the capacity and cycle of the new liquid phase microemulsion medium coating are compared with those of non-microemulsion coating. Both the capacity and cycle are superior to those of non-microemulsion coating with traditional process.

[0068] Embodiment 2:

[0069] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0070] In step 1: the ternary precursor material is Ni with a particle size of 10 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0071] Step 2: Place the mixed material into a corundum sagger, heat it to 750°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0072] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0073] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 3% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0074] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3 The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 5 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0075] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0076] Finally, 3% R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary positive electrode material. R is the liquid coating medium which is microemulsion, and 3% is the amount of emulsifier added.

[0077] 3% R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0078] Embodiment 3:

[0079] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0080] In step 1: the ternary precursor material is Ni with a particle size of 10 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0081] Step 2: Place the mixed material into a corundum sagger, heat it to 750°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0082] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0083] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 4% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0084] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 5 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0085] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0086] Finally, 4% R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary cathode material, wherein R is the liquid coating medium which is a microemulsion, and 4% is the amount of emulsifier added.

[0087] 4% R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0088] Embodiment 4:

[0089] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0090] In step 1: the ternary precursor material is Ni with a particle size of 10 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0091] Step 2: Place the mixed material into a corundum sagger, heat it to 750°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0092] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0093] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 2% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0094] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3 The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 10 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0095] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0096] Finally, 2% R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 -10-T ternary positive electrode material. Among them, R is the liquid coating medium which is a microemulsion, 2% is the amount of emulsifier added, and -10-T is 10 minutes of stirring.

[0097] 2% R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2The button battery assembled with -10-T ternary positive electrode material was subjected to capacity test (3~4.3V, 0.1C / 0.1C), cycle test (3~4.3V, 1C / 1C) 50 cycles and rate test (3~4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25℃, and the test nominal capacity was 200mAh / g.

[0098] Embodiment 5:

[0099] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0100] In step 1: the ternary precursor material is Ni with a particle size of 10 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0101] Step 2: Place the mixed material into a corundum sagger, heat it to 750°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0102] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0103] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 2% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0104] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 40 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0105] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0106] Finally, 2% R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 -40-T ternary positive electrode material. Among them, R is the liquid coating medium which is a microemulsion, 2% is the amount of emulsifier added, and -40-T is 40 minutes of stirring.

[0107] 2% R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button battery assembled with -40-T ternary positive electrode material was subjected to capacity test (3~4.3V, 0.1C / 0.1C), cycle test (3~4.3V, 1C / 1C) 50 cycles and rate test (3~4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25℃, and the test nominal capacity was 200mAh / g.

[0108] Embodiment 6:

[0109] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0110] In step 1: the ternary precursor material is Ni with a particle size of 4 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0111] Step 2: Place the mixed material into a corundum sagger, heat it to 850°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0112] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0113] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 2% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0114] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3 The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 5 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0115] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0116] Finally, SC-2%R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary cathode material. R is the liquid coating medium which is microemulsion, 2% is the amount of emulsifier added, and SC is single crystal particle.

[0117] SC-2%R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O2 The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0118] Embodiment 7:

[0119] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0120] In step 1: the ternary precursor material is Ni with a particle size of 4 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0121] Step 2: Place the mixed material into a corundum sagger, heat it to 850°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0122] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0123] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 3% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0124] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 5 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0125] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0126] Finally, SC-3%R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary cathode material. R is the liquid coating medium which is microemulsion, 3% is the amount of emulsifier added, and SC is single crystal particle.

[0127] SC-3%R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0128] Embodiment 8:

[0129] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0130] In step 1: the ternary precursor material is Ni with a particle size of 4 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0131] Step 2: Place the mixed material into a corundum sagger, heat it to 850°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0132] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0133] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 4% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0134] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3 The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 5 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0135] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0136] Finally, SC-4%R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary cathode material. R is the liquid coating medium which is microemulsion, 2% is the amount of emulsifier added, and SC is single crystal particle.

[0137] SC-4%R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0138] Embodiment 9:

[0139] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0140] In step 1: the ternary precursor material is Ni with a particle size of 4 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0141] Step 2: Place the mixed material into a corundum sagger, heat it to 850°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0142] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0143] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 2% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0144] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 10 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0145] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0146] Finally, SC-2%R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 -10-T ternary positive electrode material. Among them, R is the liquid coating medium is microemulsion, 2% is the amount of emulsifier added, SC is single crystal particles, and -10-T is 10 minutes of stirring.

[0147] SC-2%R-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button battery assembled with -10-T ternary positive electrode material was subjected to capacity test (3~4.3V, 0.1C / 0.1C), cycle test (3~4.3V, 1C / 1C) 50 cycles and rate test (3~4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25℃, and the test nominal capacity was 200mAh / g.

[0148] Embodiment 10:

[0149] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0150] In step 1: the ternary precursor material is Ni with a particle size of 4 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0151] Step 2: Place the mixed material into a corundum sagger, heat it to 850°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0152] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0153] Step 4: Add 99% ethanol solution to the reactor at a volume ratio of 50%. Add 2% Span80 and Tween80 emulsifiers at a ratio of 1:1. Stir continuously during the addition process at a speed of 500 rpm / min. After pre-stirring for 5 minutes, accelerate the stirring and increase the speed to 1500 rpm / min for 30 minutes until the solution becomes milky white and can maintain the milky state without stratification to form a microemulsion.

[0154] Step 5: Mix the treated ternary cathode material and 1000ppm Al 2 O 3 The coating additive is added to the reactor. The ratio of the treated ternary cathode material to the microemulsion is 1:1. After stirring, the stirring time is 40 minutes and the stirring speed is 1000rmp / min. The microemulsion containing the coated ternary cathode material is added to the closed filter press. After filtration, the water content of the ternary cathode material is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor.

[0155] Step 6: After the filtration, the ternary cathode material is added to the metering bin of the roller kiln, and then placed in a sagger for coating and sintering. The temperature is raised to 350°C at a rate of 1°C / min, and the sintering time is 6 hours. The sintered material is packaged after screening and demagnetization.

[0156] Finally, SC-2%R-Al@Li was obtained 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 -40-T ternary positive electrode material. Among them, R is the liquid coating medium is microemulsion, 2% is the amount of emulsifier added, SC is single crystal particles, and -40-T is 40 minutes of stirring.

[0157] SC-2%R-Al@Li 2 Ni 0.83 Co0.12 Mn 0.05 O 2 The button battery assembled with -40-T ternary positive electrode material was subjected to capacity test (3~4.3V, 0.1C / 0.1C), cycle test (3~4.3V, 1C / 1C) 50 cycles and rate test (3~4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25℃, and the test nominal capacity was 200mAh / g.

[0158] Comparative Example 1:

[0159] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0160] In step 1: the ternary precursor material is Ni with a particle size of 10 microns 0.83 Co 0.12 Mn 0.05 (OH) 2 The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0161] Step 2: Place the mixed material into a corundum sagger, heat it to 750°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0162] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0163] Step 4: Ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The positive electrode material is passed into the water-washing reactor and washed, filtered and dried using traditional processes. The water-to-material ratio is 1:1 and the washing time is 5 minutes. The filter pressure is 0.6Mpa and the filter time is 180 seconds. The drying machine is used for drying at a drying temperature of 170°C and a drying time of 90 minutes. A 99% ethanol solution is added to the reactor at a volume ratio of 50%.

[0164] Step 5: Dry the ternary layered Li 2 Ni0.83 Co 0.12 Mn 0.05 O 2 Cathode materials and Al 2 O 3 The coating additives were added into the reactor. 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Cathode materials and Al 2 O 3 The ratio of the coating additive was 1: 1. The stirring time was 5 min, the stirring speed was 1000 rpm, and the ethanol solvent was evaporated at 80°C.

[0165] Step 6: The ternary layered Li treated in step 5 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The positive electrode material is added to the metering bin of the roller kiln, loaded into the sagger for coating and sintering, and the temperature is raised to 350°C at a rate of 1°C / min. The sintering time is 6 hours, and the sintering atmosphere is oxygen. Finally, 1-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary positive electrode material.

[0166] 1-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0167] Comparative Example 2:

[0168] Step 1: Fully mix the ternary precursor material and the lithium source to form a mixed material.

[0169] In step 1: the ternary precursor material is Ni with a particle size of 4 microns 0.83 Co 0.12 Mn 0.05 (OH) 2The lithium source is industrial grade lithium hydroxide. The ternary precursor material and the lithium source are mixed in a high speed mixer at 50 Hz for 25 minutes. The molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:1.01.

[0170] Step 2: Place the mixed material into a corundum sagger, heat it to 850°C at a rate of 1°C / min, sinter it for 12 hours, and use a roller kiln to fully sinter it to form a ternary positive electrode material. The sintering atmosphere is a mixture of nitrogen and oxygen.

[0171] Step 3: After the ternary cathode material is roughly broken and crushed by a roller mill and a powder mill, it is sieved through a 400-mesh vibration screen. After demagnetization, the treated ternary cathode material is obtained, which is the ternary layered Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Positive electrode material.

[0172] Step 4: Add 99% ethanol solution into the reactor at a volume ratio of 50%. 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The positive electrode material is passed into the reactor and washed, filtered and dried using traditional processes. The water-to-material ratio is 1:1 and the washing time is 5 minutes. The filter pressure is 0.6Mpa and the filter time is 180 seconds. The drying machine is used for drying at a drying temperature of 170°C and a drying time of 90 minutes.

[0173] Step 5: Dry the SC-Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Cathode materials and Al 2 O 3 The coating additives are added into the reactor. 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Cathode materials and Al 2 O 3 The ratio of the coating additive was 1: 1. The stirring time was 5 min, the stirring speed was 1000 rpm, and the ethanol solvent was evaporated at 80°C.

[0174] Step 6: SC-Li processed in step 5 2 Ni 0.83 Co 0.12 Mn0.05 O 2 The positive electrode material is added to the metering bin of the roller kiln, loaded into the sagger for coating and sintering, and the temperature is raised to 350°C at a rate of 1°C / min. The sintering time is 6 hours, and the sintering atmosphere is oxygen. Finally, 2-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 Ternary positive electrode material.

[0175] 2-Al@Li 2 Ni 0.83 Co 0.12 Mn 0.05 O 2 The button batteries assembled with ternary positive electrode materials were subjected to capacity test (3-4.3V, 0.1C / 0.1C), cycle test (3-4.3V, 1C / 1C) 50 cycles and rate test (3-4.3V, 1C / 1C+2C / 2C+3C / 3C). All tests were carried out at room temperature of 25°C, and the test nominal capacity was 200mAh / g.

[0176] Table 1 shows the electrochemical performance comparison of the embodiment and the comparative example:

[0177]

[0178] Table 1

[0179] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0180] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a liquid microemulsion medium coated ternary cathode material, characterized in that: The following methods are included: Step 1, fully mixing the ternary precursor material and the lithium source to form a mixed material; Step 2: Place the mixed material into a sagger and use a roller kiln to fully sinter it to form a ternary positive electrode material; Step 3, the ternary positive electrode material is coarsely broken and crushed and then sieved to form a processed ternary positive electrode material; Step 4, adding the solution to the reaction kettle; adding the emulsifier, stirring continuously during the addition process, the speed is 500-800 rpm / min, and after pre-stirring for 5 minutes, the stirring is accelerated and the speed is increased to 1500-2000 rpm / min until the solution becomes milky white and can maintain the milky state without stratification, so as to form a microemulsion; Step 5, adding the treated ternary cathode material and coating additive into the reactor; After stirring, the microemulsion containing the coated ternary cathode material is added to a closed filter press; the moisture content of the ternary cathode material after filtration is not higher than 1500ppm; the microemulsion is collected and refluxed into the reactor; Step 6: After the filtration, the ternary positive electrode material is added to the metering bin of the roller kiln, and then loaded into the sagger for coating and sintering. The sintering temperature is 300-800° C. and the sintering time is 4-11 hours. The sintered material is sieved and demagnetized before packaging.

2. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 1, characterized in that: In step 1: the chemical formula of the ternary precursor material is Ni a Co b Mn (1-a-b) (OH)2(a+b+c=1); the molar ratio of the sum of nickel, cobalt and manganese in the ternary precursor material to the lithium source is 1:(1.01-1.08); the purity of the lithium source is greater than 98%; the lithium source is battery grade lithium carbonate, battery grade lithium bicarbonate, battery grade lithium hydroxide, industrial grade lithium carbonate, industrial grade lithium bicarbonate, industrial grade lithium hydroxide, lithium nitrate, lithium sulfate, lithium chloride or lithium fluoride; the ternary precursor material and the lithium source are mixed using a planetary ball mill, a high speed mixer or a plowshare mixer.

3. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 1, characterized in that: In step 2: the sintering temperature is 700-1000°C, the sintering time is 10-15h; the sintering heating rate is 1°C / min, 2°C / min, 3°C / min, 4°C / min or 5°C / min; the sagger material is corundum or mullite.

4. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 1, characterized in that: In step 3: after the ternary positive electrode material is naturally cooled to 70-100°C, it is coarsely broken and pulverized and then sieved; the coarse breaking adopts a jaw crusher and a roller mill, and the roller mill is a single-layer or double-layer; the pulverization adopts a powder machine, a jet mill or a mechanical pulverizer; the mesh number of the sieve is 200-400 mesh.

5. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 1, characterized in that: In step 4: the concentration of the solution is 80% to 90%; the solution is one of ethanol solution, methanol solution, acetone solution, methyl ether solution, and dimethyl ether solution; the emulsifier is one of Span 60, Tween 60, Span 80, Tween 80 aminocarboxylate, aminosulfate, phosphate, sodium allyl sulfonate, reactive emulsifier COPS1, allyloxy nonyl phenoxy propanol polyoxyethylene ether ammonium sulfate, allyloxy nonyl phenoxy propanol polyoxyethylene ether, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), sodium α-olefin sulfonate (AOS), SVS surfactant, (meth) acrylic acid polymerizable emulsifier, styrene polymerizable emulsifier, acrylamide polymerizable emulsifier, maleic acid polymerizable emulsifier, allyl polyether sulfonate, sodium allyl alkyl succinate sulfonate, and allyl alcohol polyoxyethylene ether series; the emulsifier accounts for 1% to 5% of the solution.

6. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 5, characterized in that: In step 4: adding the ethanol solution into the reaction kettle; adding Span80 and Tween80 as emulsifiers to ensure that the molar concentration after adding the ethanol solution is 2%.

7. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 1, characterized in that: In step 5: the type of coating additive is nano-scale metal oxide, nano-scale metal phosphate or nano-scale ion conductive material; the nano-scale metal oxide is Al2O3, ZrO2, TiO2 or WO3; the nano-scale metal phosphate is AlPO4, MnPO4; the nano-scale ion conductive material is LiAlO2, Li2TiO3.

8. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 7, characterized in that: In step 5: the treated ternary positive electrode material and the coating additive are added to the reactor, the addition ratio of the coating additive is 500-5000ppm, and the ratio of the treated ternary positive electrode material to the microemulsion is 1:1-3; after stirring, the microemulsion containing the coated ternary positive electrode material is added to the closed filter press; the stirring time is 3-60min, and the stirring speed is 800-2000rmp / min.

9. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 8, characterized in that: In step 5: after stirring, the microemulsion containing the coated ternary positive electrode material is added to a closed filter press; the closed filter press has a discharge port and a liquid receiving port for collecting the microemulsion, and the microemulsion is collected and refluxed into the reactor; the closed filter press can be introduced with an inert gas; the inert gas is nitrogen.

10. The method for preparing a liquid microemulsion medium coated ternary cathode material according to claim 1, characterized in that: In step 6: the amount of the sagger is 3 to 6 kg.

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