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CN109546123B - Vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material and preparation method thereof - Google Patents

Vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material and preparation method thereof Download PDF

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CN109546123B
CN109546123B CN201811408690.9A CN201811408690A CN109546123B CN 109546123 B CN109546123 B CN 109546123B CN 201811408690 A CN201811408690 A CN 201811408690A CN 109546123 B CN109546123 B CN 109546123B
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nickel
manganese
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童汇
周其杰
王旭
姚赢赢
张宝
喻万景
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Central South University
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    • H01—ELECTRIC ELEMENTS
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    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
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    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
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    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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Abstract

五氧化二钒包覆核壳结构梯度镍钴锰正极材料及制备方法，所述正极材料由五氧化二钒包覆层包覆核壳结构梯度镍钴锰正极材料而成；其化学式为V2O5@ LiNixCoyMn(1‑x‑y)O2，其中，0.5≤x≤0.85，0.05≤y≤0.4，1‑x‑y＞0；所述核壳结构梯度镍钴锰正极材料由核壳结构梯度镍钴锰正极材料前驱体混锂烧结所得。所述制备方法为：（1）将正极材料前驱体陈化，过滤，洗涤，干燥；（2）加入锂源，研磨，预烧后，烧结；（3）与钒源在醇溶液中混合，超声，加热反应；（4）在含氧气氛下，热处理，即成。本发明正极材料组装的电池放电比容量高、循环及倍率性能好；本发明方法简单、成本低、适于工业化生产。

Figure 201811408690

Vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material and preparation method, the positive electrode material is made of vanadium pentoxide coating layer coating core-shell structure gradient nickel-cobalt-manganese positive electrode material; its chemical formula is V 2 O 5 @ LiNi x Co y Mn (1‑x‑y) O 2 , wherein, 0.5≤x≤0.85, 0.05≤y≤0.4, 1‑x‑y>0; the core-shell structure gradient nickel-cobalt-manganese positive electrode The material is obtained by sintering a precursor of a core-shell structure gradient nickel-cobalt-manganese cathode material mixed with lithium. The preparation method is as follows: (1) ageing, filtering, washing and drying the positive electrode material precursor; (2) adding a lithium source, grinding, pre-sintering, and then sintering; (3) mixing with a vanadium source in an alcohol solution, Ultrasonic, heating reaction; (4) under oxygen-containing atmosphere, heat treatment, and serve. The battery assembled with the positive electrode material of the invention has high discharge specific capacity, good cycle and rate performance; the method of the invention is simple, low in cost, and suitable for industrial production.

Figure 201811408690

Description

Vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material and preparation method thereof
Technical Field
The invention relates to a nickel-cobalt-manganese positive electrode material and a preparation method thereof, in particular to a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material and a preparation method thereof.
Background
In the twenty-first century, the problems of large-scale energy shortage and environmental pollution are becoming more serious worldwide, forcing people to find green power systems capable of replacing traditional fossil energy and storing new energy (solar energy, wind energy, nuclear energy and the like). Lithium ion batteries are widely used in devices such as mobile phones, digital cameras, and portable personal computers due to their excellent energy density, rate capability, and long service life, and their application targets are shifting from small-sized mobile devices to large-sized electric vehicle battery series (batteries for vehicles such as pure electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles) and energy storage systems. The key points of whether the lithium ion battery can be applied to a large-scale power battery and an energy storage battery are five factors such as energy density, power density, service life, safety, price and the like. In order to solve these problems, it is necessary to optimize the battery assembly process and the battery management system, and to strengthen the constituent components (positive electrode material, negative electrode material, separator, electrolyte, etc.) of the lithium ion battery system. In a lithium ion battery system, a positive electrode material restricts the development of the overall performance of the battery, and a ternary material serving as one of the positive electrode materials of the lithium ion battery has the advantages of high voltage, high specific capacity, low cost and the like, so that the ternary material is one of the positive electrode materials of the lithium ion battery which has the acknowledged most development prospect.
CN102637871A discloses a lithium ion active oxide V2O5The method for coating the lithium ion battery anode material comprises the steps of dissolving a vanadium source in a medium to form a solution, adding the lithium ion battery anode material or a precursor thereof, drying and sintering at a low temperature to obtain the modified lithium ion battery anode material. However, the method needs a spray drying method, the preparation process is complicated, the initial discharge is only 170mAh/g of specific capacity at the rate of 2C, and the performance at high rate is not good.
CN106654201A discloses a composite ternary material and a preparation method thereof, wherein a vanadium source is added into an oxalic acid solution, then a phosphorus source and a lithium source are added, then the ternary material is added and uniformly stirred, then ethylene glycol and ethylenediamine are dropwise added, low-temperature heating is carried out to obtain a precursor, and then high-temperature sintering is carried out to obtain the ternary material with a coating layer. Although the coating layer slows down the catalytic reaction of the ternary material to the electrolyte, relieves the instant accumulation of heat and can inhibit the dangerous state of the battery. However, the sintering temperature of the method is 800-860 ℃, the temperature is high, the energy consumption is large, the 1C first discharge capacity is only 169mHh/g, and the capacity is low.
CN107230771A discloses a method for coating lithium ion battery positive electrode material nickel cobalt lithium manganate with vanadium phosphate, which comprises mixing a vanadium source, phosphate and a reducing agent in deionized water according to a certain proportion, carrying out hydrothermal reaction, filtering, washing and drying to obtain vanadium phosphate, mixing the prepared vanadium phosphate and a ternary material according to a certain proportion, and sintering to obtain a target product. Although the method can effectively improve the capacity and the cycle performance of the lithium ion battery, the method firstly needs to synthesize a coating, has complex processes, needs 20-48 hours in the process of synthesizing the coating, consumes overlong time, has low efficiency, is not beneficial to industrial production, and has the capacity retention of 20 cycles of cyclic discharge at 0.1C rate of only 91.92 percent and poor cycle performance.
CN103700825A discloses a doping and coating method of a ternary positive electrode material, which is to mix a ternary material precursor, lithium carbonate and vanadium pentoxide, sinter the mixture, mix lithium fluoride into the mixture to perform secondary sintering, dissolve the mixture in alcohol, add isopropanol into the alcohol, dry the mixture, and finally put the mixture into a muffle furnace to preserve heat. Although the method can improve the efficiency of the material and further improve the cyclicity and high-temperature stability of the battery, the method needs three times of sintering, not only has complex working procedures, but also is not beneficial to energy conservation and industrial production, and the specific capacity after 100 cycles of cyclic discharge at 0.2C multiplying power is only 176mAh/g, and the cyclicity is not good.
Therefore, a ternary material is urgently needed to be found, and the rate and the cycle performance of the ternary material are optimized while high specific discharge capacity is obtained.
Disclosure of Invention
The invention aims to solve the technical problem of overcoming the defects in the prior art and providing the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material which is high in assembled battery discharge specific capacity and good in cycle and rate performance.
The invention further aims to solve the technical problem of overcoming the defects in the prior art and provides a preparation method of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material, which is simple in process, low in cost and suitable for industrial production.
The technical scheme adopted by the invention for solving the technical problems is as follows: the vanadium pentoxide coating core-shell structure gradient nickel-cobalt-manganese cathode material is formed by coating the core-shell structure gradient nickel-cobalt-manganese cathode material with a vanadium pentoxide coating layer; the chemical formula of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material is V2O5@ LiNixCoyMn(1-x-y)O2Wherein x is more than or equal to 0.5 and less than or equal to 0.85, y is more than or equal to 0.05 and less than or equal to 0.4, and 1-x-y is more than or equal to 0; the core-shell structure gradient nickel-cobalt-manganese cathode material is prepared by sintering a core-shell structure gradient nickel-cobalt-manganese cathode material precursor mixed with lithium. The core is nickel cobalt lithium manganate prepared by taking hydroxide precipitate of nickel cobalt manganese as a precursor, the structure is compact, the compaction density of the material can be ensured, and the shell is nickel cobalt lithium manganate prepared by taking nickel cobalt manganese carbonate as a precursor and has micropores, so that the lithium ions can be conveniently de-intercalated in the charging and discharging reaction process, and the structural change of the material caused by the volume change in the charging and discharging reaction process can be prevented; the coating layer of vanadium pentoxide can provide a lithium ion channel in the charge and discharge process to improve the ionic conductivity, the coating layer can provide a protective shell to inhibit the material structure change in the charge and discharge process, and simultaneously, the surface V is2O5The coating layer has good stability in air and electrolyte, and can better isolate CO in the air2/H2And O and electrolyte greatly improve the air storage performance of the material and the electrochemical cycling stability of the material.
Preferably, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material is spherical particles with the average particle size of 3-12 microns.
Preferably, the thickness of the coating layer of the vanadium pentoxide is 3-10 nm, and the mass percentage of the vanadium pentoxide is 1-7% (more preferably 2-5%). Too thick or too much coating results in too great a loss of initial capacity of the material, while too thin or too little coating results in insufficient coating material to achieve the desired modification effect.
Preferably, the content of nickel is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the content of manganese, cobalt and vanadium is uniformly distributed in the center of the core-shell structure particles and the shell layer. Because the core-shell structure gradient nickel-cobalt-manganese cathode material has micropores or fine gaps, a vanadium source can permeate to the inner diameter of particles along the micropores or the gaps in the wrapping process, and is diffused in the sintering process to generate vanadium pentoxide which is retained in the gaps.
Preferably, the core of the core-shell structure gradient nickel-cobalt-manganese positive electrode material is nickel-cobalt lithium manganate obtained by mixing and sintering nickel-cobalt-manganese hydroxide precipitate as a precursor, and the shell is nickel-cobalt lithium manganate obtained by mixing and sintering nickel-cobalt-manganese carbonate as a precursor.
Preferably, the diameter of the inner core is 2.5-9.0 μm, and the thickness of the shell layer is 0.3-3.0 μm.
Preferably, the preparation method of the core-shell structure gradient nickel-cobalt-manganese cathode material precursor comprises the following steps:
1) pumping the low-nickel-content nickel-cobalt-manganese solution into a container filled with the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution, stirring, simultaneously pumping the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution continuously pumped into the reaction kettle filled with the ammonia solution, simultaneously adjusting the ammonia concentration of the reaction system by using the ammonia water, adjusting the pH value of the reaction system by using a hydroxide precipitator solution, stirring for coprecipitation reaction until the average particle size of particles grows to 2.5-9.0 mu m, obtaining a precursor nuclear material, continuing to perform the above operation, only replacing the hydroxide precipitator solution by a carbonate precipitator solution for adjusting the pH value of the reaction system, stirring for coprecipitation reaction until the low-nickel-content nickel-cobalt-manganese solution and the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution are completely fed, and obtaining a solution containing a core-shell material;
2) and (2) stirring the solution containing the precursor core-shell material obtained in the step (1) for aging, filtering, washing and drying to obtain the core-shell structure gradient nickel-cobalt-manganese cathode material precursor.
Preferably, in the step 1), the feeding speed of the low-nickel-content nickel-cobalt-manganese solution is 20-60 mL/h, and the feeding speed of the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution continuously pumped into the low-nickel-content nickel-cobalt-manganese solution is 50-100 mL/h.
Preferably, in the step 1), in the low-nickel-content nickel-cobalt-manganese solution, the concentration of metal ions is 1 to 3mol/L, the mol percentage of Ni in the total metal ions is 40 to 70%, the mol percentage of Co in the total metal ions is 10 to 40%, the mol percentage of Mn in the total metal ions is 20 to 50%, and the sum of the Ni, Co, and Mn ions is 100%.
Preferably, in the step 1), in the high nickel content nickel-cobalt or nickel-cobalt-manganese solution, the concentration of metal ions is 1 to 3mol/L, the mol percentage of Ni in the total metal ions is 60 to 90%, the mol percentage of Co in the total metal ions is 10 to 40%, the mol percentage of Mn in the total metal ions is 0 to 30%, and the total of the Ni, Co, and Mn ions is 100%.
Preferably, in step 1), in the same reaction system, the nickel content of the low nickel content nickel-cobalt-manganese solution is lower than that of the high nickel content nickel-cobalt or nickel-cobalt-manganese solution.
Preferably, in the step 1), the volume ratio of the ammonia water solution, the low nickel content nickel cobalt manganese solution and the high nickel content nickel cobalt or nickel cobalt manganese solution in the reaction kettle is 0.1-10: 0.8-1.2: 1 (more preferably 0.5-2.5: 0.8-1.2: 1).
Preferably, in the step 1), the molar concentration of the ammonia water solution is 0.3-0.5 mol/L.
Preferably, in the step 1), ammonia water is used for adjusting the ammonia water concentration of the reaction system to be kept at 0.3-0.5 mol/L.
Preferably, in the step 1), the mass concentration of the ammonia water for adjusting the ammonia water concentration of the reaction system is 25-28%.
Preferably, in the step 1), the pH value of the reaction system is adjusted to be 10.5-11.5 by using a hydroxide precipitator solution.
Preferably, in the step 1), the molar concentration of the hydroxide precipitant solution is 5-10 mol/L.
Preferably, in step 1), the hydroxide precipitant is one or more of sodium hydroxide, potassium hydroxide or lithium hydroxide.
Preferably, in the step 1), the pH value of the reaction system is adjusted to be 8.5-10.5 by using a carbonate precipitant solution.
Preferably, in the step 1), the molar concentration of the carbonate precipitant solution is 0.5-1.5 mol/L.
Preferably, in step 1), the carbonate precipitant is one or more of sodium carbonate, potassium carbonate, lithium carbonate, sodium bicarbonate or potassium bicarbonate.
Preferably, in the step 1), in the coprecipitation reaction of the precursor core material and the precursor core-shell layer material, the stirring speed is 600-1200 r/min, and the temperature is 50-70 ℃.
Preferably, in step 1), the low nickel content nickel cobalt manganese solution and the high nickel content nickel cobalt or nickel cobalt manganese solution are mixed solutions of soluble nickel salt and soluble cobalt salt or soluble nickel salt, soluble cobalt salt and soluble manganese salt.
Preferably, the soluble nickel salt is one or more of nickel sulfate, nickel nitrate, nickel acetate or nickel chloride.
Preferably, the soluble cobalt salt is one or more of cobalt sulfate, cobalt nitrate, cobalt acetate or cobalt chloride.
Preferably, the soluble manganese salt is one or more of manganese sulfate, manganese nitrate, manganese acetate or manganese chloride.
Preferably, in the step 2), the stirring speed is 400-800 r/min.
Preferably, in the step 2), the aging temperature is 50-80 ℃ and the aging time is 5-15 h.
Preferably, in the step 2), the drying temperature is 50-100 ℃ and the drying time is 5-15 h.
The core-shell structure gradient nickel-cobalt-manganese cathode material precursor can also be prepared by other prior art.
The technical scheme adopted for further solving the technical problems is as follows: the preparation method of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material comprises the following steps:
(1) aging, filtering, washing and drying the precursor of the core-shell structure gradient nickel-cobalt-manganese cathode material to obtain an aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor;
(2) adding a lithium source into the aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor obtained in the step (1), grinding, pre-sintering and sintering to obtain a core-shell structure gradient nickel-cobalt-manganese cathode material;
(3) mixing the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in the step (2) with a vanadium source in an alcohol solution, performing ultrasonic treatment, heating, stirring and reacting until the mixture is evaporated to dryness, and obtaining mixed powder;
(4) and (4) carrying out heat treatment on the mixed powder obtained in the step (3) in an oxygen-containing atmosphere to obtain the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material.
Preferably, in the step (1), the aging temperature is 50-80 ℃, the rotation speed is 600-1200 r/min, and the time is 5-15 h. The aging is more beneficial to the more uniform growth of the particles. If the aging temperature is too high or the aging time is too long, side reactions occur, and if the aging temperature is too low or the aging time is too short, the purpose of aging is difficult to achieve.
Preferably, in the step (1), the drying temperature is 50-100 ℃ and the drying time is 5-15 h. The drying is intended to remove the solvent, and some drying temperatures that are too high or too long may cause side reactions, some drying temperatures that are too low may cause too long a drying time that affects efficiency, and some drying times that are too short may cause the material to contain residual solvent.
Preferably, in the step (2), the molar ratio of the lithium element in the lithium source to the sum of the mole numbers of the nickel, cobalt and manganese elements in the core-shell structure gradient nickel-cobalt-manganese cathode material precursor is 1.01-1.07: 1. If the addition amount of the lithium element is too low, the lithium element is insufficient, so that the discharge specific capacity is too low; if the amount of the added lithium element is too high, the ratio of the active material decreases, and the specific discharge capacity also decreases.
Preferably, in step (2), the lithium source is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate or lithium acetate, and hydrates thereof.
Preferably, in the step (2), the rotation speed of the grinding is 600-1000 r/min, and the time is 5-10 min. If the grinding speed is too low or the grinding time is too short, the material mixing is not uniform, and if the grinding speed is too high or the grinding time is too long, the core-shell structure of the material is damaged.
Preferably, in the step (2), the pre-sintering temperature is 350-550 ℃ and the time is 3-6 h. The pre-sintering is to remove the residual moisture in the precursor of the nickel-cobalt-manganese anode material, realize dehydration, melt the lithium source at the same time, and mix the materials more uniformly on a microscopic level. If the pre-sintering temperature is too low or the time is too short, the material mixing is not uniform, and if the pre-sintering temperature is too high or the time is too long, the energy waste is caused.
Preferably, in the step (2), the sintering temperature is 650-950 ℃, and the time is 8-24 h. During sintering, Li2And reacting the O with the grain boundary of the metal oxide to gradually generate the layered nickel cobalt lithium manganate material. If the sintering temperature is too low or the sintering time is too long, the material reaction is incomplete, the crystal form is incomplete, and the performance of the material is affected.
Preferably, in the step (3), the molar ratio of the vanadium element in the vanadium source to the sum of the mole numbers of the nickel, cobalt and manganese elements in the core-shell structure gradient nickel-cobalt-manganese cathode material is 0.01-0.10: 1 (more preferably 0.015-0.055: 1). If the amount of the vanadium source used as the raw material of the coating material is too large, the initial capacity of the material is lowered, and if the amount of the vanadium source used as the raw material of the coating material is too small, the desired modification effect is hardly obtained.
Preferably, in the step (3), the vanadium source is one or more of vanadium acetylacetonate, vanadyl acetylacetonate, ammonium metavanadate and the like. The vanadium source is easily dissolved in the alcohol solution and can be uniformly mixed with the base material.
Preferably, in the step (3), the volume-to-mass ratio (mL/g) of the alcoholic solution to the total mass of the core-shell structure gradient nickel-cobalt-manganese cathode material and the vanadium source is 10-60: 1 (more preferably 36-56: 1). The alcohol solution is used for ultrasonic dispersion, so that the vanadium source serving as the raw material of the coating can be dissolved, and the vanadium source can be uniformly mixed with the base material. If the amount of the alcohol solution is too low, the mixing is not uniform, and if the amount of the alcohol solution is too high, unnecessary waste is generated.
Preferably, in the step (3), the alcohol solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol.
Preferably, in the step (3), the frequency of the ultrasonic dispersion is 30-40 kHz, and the time is 4-8 h. If the ultrasonic frequency is too low or the ultrasonic time is too short, the dispersion is not complete enough, and if the ultrasonic frequency is too high or the ultrasonic time is too long, the integrity of the core-shell structure of the material is affected.
Preferably, in the step (3), the temperature of the heating and stirring reaction is 40-60 ℃, and the stirring speed is 100-200 r/min. The heating reaction is performed to improve the solubility of the vanadium source as the raw material of the coating material and further enhance the uniformity of the mixing. If the temperature of the heating/stirring reaction is too low, the dissolved starting material is crystallized, and if the temperature is too high, side reactions are likely to occur. If the stirring speed in the reaction process is too slow, the mixture is not uniform, and if the stirring speed is too fast, the integrity of the core-shell structure material is affected.
Preferably, in the step (4), the temperature of the heat treatment is 300-600 ℃ and the time is 4-8 h. And in the heat treatment process, the vanadium source can generate decomposition reaction, and vanadium pentoxide is generated on the surface of the substrate ternary material. If the temperature of the heat treatment is too low or the time is too short, the target material is difficult to be produced, and if the temperature of the heat treatment is too high or the time is too long, the core-shell structure and the clad structure of the material are destroyed, and a side reaction occurs.
Preferably, in the step (4), the oxygen-containing atmosphere is one or more of an air atmosphere, an oxygen atmosphere, an ozone atmosphere, or the like.
The invention has the following beneficial effects:
(1) the core-shell structure gradient nickel-cobalt-manganese cathode material is formed by coating a core-shell structure gradient nickel-cobalt-manganese cathode material with a vanadium pentoxide coating layer with the thickness of 3-10 nm, and the average particle size is 4-12 mu m; the core of the core-shell structure gradient nickel-cobalt-manganese positive electrode material is nickel-cobalt-lithium manganate obtained by mixing and sintering nickel-cobalt-manganese hydroxide precipitate as a precursor, the diameter of the nickel-cobalt-lithium manganate is 2.5-9.0 mu m, the shell layer is nickel-cobalt-lithium manganate obtained by mixing and sintering nickel-cobalt-manganese carbonate as a precursor, and the thickness of the shell layer is 1-3 mu m; the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the contents of manganese, cobalt and vanadium are uniformly distributed in the center of the core-shell structure particles and the shell layer; the core is compact, and the shell has a microporous structure, so that lithium ions can be more smoothly de-intercalated, the ionic conductivity of the material is improved, and the material performance is optimized;
(2) the positive electrode material is assembled into a battery, the first discharge capacity can reach as high as 195mAh/g under the current density of 0.1C (20 mA/g), the discharge specific capacity can reach as high as 151mAh/g under the current density of 10C (2000 mA/g), and the discharge specific capacity is high; under the current density of 1C (200 mA/g), after circulating for 100 circles, the discharge specific capacity is still kept at 165mAh/g, the capacity retention rate is 89.2%, and excellent circulation and rate performance is shown;
(3) the method has simple process and low cost, and is suitable for industrial production.
Drawings
FIG. 1 is an XRD (X-ray diffraction) diagram of a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material in example 1 of the invention;
FIG. 2 is an SEM image of a vanadium pentoxide coated core-shell structure gradient Ni-Co-Mn positive electrode material in example 1 of the present invention;
FIG. 3 is a TEM image of the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material in example 1 of the present invention;
FIG. 4 is a focused ion beam test chart of a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material in example 1 of the present invention;
FIG. 5 is a line-scan EDS plot of the four elements Ni, Co, Mn, V of the particle cross-section of FIG. 4;
FIG. 6 is a first-turn charge-discharge curve diagram of a battery assembled by the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material in embodiment 1 of the present invention;
FIG. 7 is a discharge cycle diagram of a battery assembled by the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material in embodiment 1 of the present invention;
FIG. 8 is a discharge rate diagram of a battery assembled with a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material in embodiment 1 of the present invention;
FIG. 9 is a first-turn charge-discharge curve diagram of a battery assembled by the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material in embodiment 2 of the present invention;
FIG. 10 is a first-turn charge-discharge curve diagram of a battery assembled by the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material in embodiment 3 of the present invention;
FIG. 11 is a discharge cycle diagram of a battery assembled by the core-shell structure gradient nickel-cobalt-manganese cathode material of comparative example 1.
Detailed Description
The invention is further illustrated by the following examples and figures.
The chemical reagents used in the examples of the present invention, unless otherwise specified, are commercially available in a conventional manner.
Core-shell structure gradient nickel-cobalt-manganese cathode material precursor reference example 1
1) Pumping 2L of low nickel content nickel cobalt manganese solution (mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate, wherein the molar percentages of Ni, Co and Mn in the total metal ions are 70%, 10% and 20% in sequence, and the metal ion concentration is 2 mol/L) into a container filled with 2L of high nickel content nickel cobalt solution (mixed solution of nickel sulfate and cobalt sulfate, wherein the molar percentages of Ni and Co in the total metal ions are 90% and 10% in sequence, and the metal ion concentration is 2 mol/L) at a feeding speed of 40mL/h, stirring, simultaneously pumping high nickel content nickel cobalt solution continuously pumped into the low nickel content nickel cobalt manganese solution into a reaction kettle filled with 2L of ammonia water solution with a molar concentration of 0.45mol/L and a volume of 5L, and simultaneously adjusting the ammonia water concentration of the reaction system to be 0.45mol/L by using ammonia water with a mass concentration of 25%, adjusting the pH value of a reaction system to be 11.4 by using 10mol/L sodium hydroxide solution, stirring the solution at 60 ℃ at 1000r/min to perform coprecipitation reaction until the average particle size of particles grows to 3.5 mu m to obtain a precursor core material, continuing to perform the operation, only replacing the sodium hydroxide solution with 1mol/L sodium carbonate solution for adjusting the pH value of the reaction system to be 9.5, stirring the solution at 60 ℃ at 1000r/min to perform coprecipitation reaction until the feeding of the low-nickel-content nickel-cobalt-manganese solution and the high-nickel-content nickel-cobalt solution is finished to obtain a solution containing a precursor core shell material;
2) stirring the solution containing the precursor core-shell material obtained in the step 1) at 600r/min and 60 ℃ for aging for 10h, filtering, washing with deionized water, and drying at 80 ℃ for 10h to obtain a core-shell structure gradient nickel-cobalt-manganese cathode material precursor Ni0.75Co0.12Mn0.13(OH)2。
Reference example 2 of core-shell structure gradient nickel-cobalt-manganese cathode material precursor
1) Pumping 1.6L of nickel-cobalt-manganese solution with low nickel content (mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the molar percentages of Ni, Co and Mn in the total metal ions are 40%, 30% and 30% in sequence, and the concentration of metal ions is 2.5 mol/L) into a container filled with 2L of nickel-cobalt-manganese solution with high nickel content (mixed solution of nickel nitrate, cobalt nitrate and manganese nitrate, wherein the molar percentages of Ni, Co and Mn in the total metal ions are 80%, 10% and 10% in sequence, and the concentration of metal ions is 2.5 mol/L) at a feeding speed of 30mL/h, stirring, simultaneously pumping high nickel-cobalt-manganese solution with low nickel content into a reaction kettle with a volume of 5L, and simultaneously adjusting the concentration of ammonia water of the reaction system to be 0.45mol/L by using ammonia water with a mass concentration of 25%, adjusting the pH value of a reaction system to be 11.0 by using a 5mol/L sodium hydroxide solution, stirring the solution at 55 ℃ at 800r/min to perform coprecipitation reaction until the average particle size of particles grows to 4 mu m to obtain a precursor core material, continuing to perform the operation, only replacing the sodium hydroxide solution with a 0.8mol/L sodium carbonate solution to adjust the pH value of the reaction system to be 9, stirring the solution at 55 ℃ at 800r/min to perform coprecipitation reaction until the feeding of the low-nickel-content nickel-cobalt-manganese solution and the high-nickel-content nickel-cobalt-manganese solution is finished to obtain a solution containing the precursor core-shell material;
2) the product obtained in the step (1) containsStirring the solution of the material of the core-shell body layer at the temperature of 70 ℃ at 500r/min for aging for 12h, filtering, washing with deionized water, and drying at the temperature of 60 ℃ for 8h to obtain a precursor Ni of the core-shell structure gradient nickel-cobalt-manganese ternary cathode material0.6Co0.2Mn0.2(OH)2。
Vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material embodiment 1
The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material is formed by coating a core-shell structure gradient nickel-cobalt-manganese positive electrode material with a vanadium pentoxide coating layer; the chemical formula of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material is V2O5@ LiNi0.75Co0.12Mn0.13O2(ii) a The core-shell structure gradient nickel-cobalt-manganese cathode material is prepared from a precursor Ni of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in reference example 10.75Co0.12Mn0.13(OH)2Mixed lithium is sintered; the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material is spherical particles with the average particle size of 4 mu m; the thickness of the coating layer of the vanadium pentoxide is 5nm, and the mass percent of the vanadium pentoxide is 3%; the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the contents of manganese, cobalt and vanadium are uniformly distributed in the center of the core-shell structure particles and the shell layer; the core of the core-shell structure gradient nickel-cobalt-manganese cathode material is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking hydroxide precipitation of nickel-cobalt-manganese as a precursor, and the shell layer is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking nickel-cobalt-manganese carbonate as a precursor; the diameter of the inner core is 3.5 μm, and the thickness of the shell layer is 0.5 μm.
Preparation method of vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material in embodiment 1
(1) 1g (0.01038 mol) of precursor Ni of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in reference example 10.75Co0.12Mn0.13(OH)2Aging at 60 ℃ and at a rotating speed of 800r/min for 10h, filtering, washing with deionized water, and drying at 80 ℃ for 10h to obtain an aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor；
(2) Adding 0.458g (0.0109 mol) of lithium hydroxide monohydrate (the molar ratio of the lithium element to the sum of the molar numbers of the nickel, cobalt and manganese elements is 1.05: 1) into the precursor of the aged core-shell structure gradient nickel-cobalt-manganese positive electrode material obtained in the step (1), grinding for 8min at 800r/min, presintering for 4h at 450 ℃, and sintering for 12h at 750 ℃ to obtain the core-shell structure gradient nickel-cobalt-manganese positive electrode material;
(3) mixing 1g of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in the step (2) and 0.087g (0.00033 mol) of vanadyl acetylacetonate in 50mL of anhydrous ethanol solution, carrying out ultrasonic treatment for 6h at 35kHz, heating, stirring and reacting at 50 ℃ and at the rotating speed of 150r/min until the mixture is evaporated to dryness, and obtaining mixed powder;
(4) carrying out heat treatment on the mixed powder obtained in the step (3) for 6h at 500 ℃ in the air atmosphere to obtain a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material V2O5@ LiNi0.75Co0.12Mn0.13O2。
As shown in FIG. 1, the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The nickel-cobalt-manganese ternary cathode material is a pure-phase nickel-cobalt-manganese ternary cathode material, and the crystal structure of the nickel-cobalt-manganese ternary cathode material is not changed after vanadium pentoxide is coated.
As shown in FIG. 2, the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2Is spherical particles with the particle size of 4 mu m and has uniform appearance.
As shown in FIG. 3, the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The outer layer of the particle is provided with a relatively uniform coating layer with the thickness of 5 nm.
As shown in fig. 4 and 5, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the present invention2O5@ LiNi0.75Co0.12Mn0.13O2The diameter of the inner core is 3.5 mu m, the thickness of the shell layer is 0.5 mu m, the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese anode material to the surface of the shell layer, and the manganese, cobalt and vanadium content is uniformly distributed in the center of the core-shell structure particles and the shell layer.
Assembling the battery: weighing 0.16 g of vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2Adding 0.02g of acetylene black serving as a conductive agent, 0.02g of polyvinylidene fluoride serving as a binder and N-methyl pyrrolidone serving as a dispersing agent, uniformly mixing, coating on an aluminum foil to prepare a negative plate, and assembling the negative plate into a CR2025 button cell by taking a metal lithium plate as a positive electrode, a pe and pp composite membrane as a diaphragm and 1mol/L lithium hexafluorophosphate/DMC: EC (volume ratio of 1: 1) as electrolyte in a vacuum glove box.
As shown in FIG. 6, the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The specific first discharge capacity at 0.1C (20 mA/g) rate was 195 mAh/g.
As shown in FIG. 7, the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2Under the multiplying power of 1C (mA/g), after 100 cycles, the discharge specific capacity is still kept at 165mAh/g, the capacity retention rate is 89.2%, and the excellent cycle performance is shown.
As shown in FIG. 8, the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The first discharge specific capacity under the multiplying power of 0.1C (20 mA/g) is 192mAh/g, after 10 cycles, the discharge specific capacity is still maintained at 194mAh/g, and the capacity retention rate is 101%; the first discharge specific capacity after switching to the multiplying power of 0.5C (100 mA/g) is 188mAh/g, after 10 cycles, the discharge specific capacity is still maintained at 188mAh/g, and the capacity is maintainedThe rate is 100%; after the discharge capacity is switched to 1C (200 mA/g) multiplying power, the first discharge specific capacity is 180mAh/g, after 10 cycles, the discharge specific capacity is still kept at 179.5mAh/g, and the capacity retention rate is 99.7%; after the discharge capacity is switched to 2C (400 mA/g) multiplying power, the first discharge specific capacity is 172.5mAh/g, after 10 cycles, the discharge specific capacity is still kept at 171mAh/g, and the capacity retention rate is 99.1%; after the discharge capacity is switched to 5C (1000 mA/g) multiplying power, the first discharge specific capacity is 167.5mAh/g, after 10 cycles, the discharge specific capacity is still kept at 164mAh/g, and the capacity retention rate is 97.9%; the first discharge specific capacity after switching to the high current density of 10C (2000 mA/g) is 151mAh/g, after 10 cycles, the discharge specific capacity is still kept at 146mAh/g, the capacity retention rate is 96.7%, and the rate capability is excellent.
Embodiment 2 of vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material
The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material is formed by coating a core-shell structure gradient nickel-cobalt-manganese positive electrode material with a vanadium pentoxide coating layer; the chemical formula of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material is V2O5@ LiNi0.6Co0.2Mn0.2O2(ii) a The core-shell structure gradient nickel-cobalt-manganese cathode material is prepared from a precursor Ni of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in reference example 20.6Co0.2Mn0.2(OH)2Mixed lithium is sintered; the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material is spherical particles with the average particle size of 4.6 mu m; the thickness of the coating layer of the vanadium pentoxide is 3nm, and the mass percent of the vanadium pentoxide is 2%; the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the contents of manganese, cobalt and vanadium are uniformly distributed in the center of the core-shell structure particles and the shell layer; the core of the core-shell structure gradient nickel-cobalt-manganese cathode material is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking hydroxide precipitation of nickel-cobalt-manganese as a precursor, and the shell layer is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking nickel-cobalt-manganese carbonate as a precursor; the diameter of the inner core is 4 μm, and the thickness of the shell layer is 0.6 μm.
Embodiment 2 of the method for preparing vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material
(1) 1g (0.01065 mol) of precursor Ni of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in reference example 20.6Co0.2Mn0.2(OH)2Aging at 50 ℃ and a rotation speed of 1000r/min for 12h, filtering, washing with deionized water, and drying at 100 ℃ for 8h to obtain an aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor;
(2) adding 1.163g (0.0114 mol) of lithium acetate dihydrate (the molar ratio of the lithium element to the sum of the molar numbers of the nickel, the cobalt and the manganese element is 1.07: 1) into the precursor of the aged core-shell structure gradient nickel-cobalt-manganese positive electrode material obtained in the step (1), grinding for 10min at 700r/min, pre-sintering for 5h at 400 ℃, and sintering for 8h at 800 ℃ to obtain the core-shell structure gradient nickel-cobalt-manganese positive electrode material;
(3) mixing 1g of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in the step (2) with 0.074g (0.00021 mol) of vanadium acetylacetonate in 60mL of anhydrous ethanol solution, carrying out ultrasonic treatment for 8h at 30kHz, heating and stirring at 40 ℃ and at the rotating speed of 200r/min until the mixture is evaporated to dryness, and obtaining mixed powder;
(4) carrying out heat treatment on the mixed powder obtained in the step (3) for 8 hours at 550 ℃ in the air atmosphere to obtain a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material V2O5@ LiNi0.6Co0.2Mn0.2O2。
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.6Co0.2Mn0.2O2The nickel-cobalt-manganese ternary cathode material is a pure-phase nickel-cobalt-manganese ternary cathode material, and the crystal structure of the nickel-cobalt-manganese ternary cathode material is not changed after vanadium pentoxide is coated.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.6Co0.2Mn0.2O2Is spherical particles with the particle size of 4.6 mu m and has uniform appearance.
Through detection, the vanadium pentoxide obtained in the embodiment of the inventionGradient nickel-cobalt-manganese cathode material V with coated core-shell structure2O5@ LiNi0.6Co0.2Mn0.2O2The outer layer of the particle is provided with a relatively uniform coating layer with the thickness of 3 nm.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.6Co0.2Mn0.2O2The diameter of the core is 4 μm, the thickness of the shell is 0.6 μm, the nickel content gradually decreases from the center of the core-shell structure gradient nickel-cobalt-manganese anode material to the surface of the shell, and the manganese, cobalt and vanadium content is uniformly distributed in the center of the core-shell structure particles and the shell.
Assembling the battery: the same as in example 1.
As shown in fig. 9, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the present invention2O5@ LiNi0.6Co0.2Mn0.2O2The specific first discharge capacity at 0.1C (20 mA/g) rate was 193 mAh/g.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.6Co0.2Mn0.2O2Under the multiplying power of 1C (mA/g), after circulating for 100 circles, the discharge specific capacity is still kept at 158mAh/g, the capacity retention rate is 88.3%, and the excellent circulating performance is shown.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.6Co0.2Mn0.2O2Under the high current density of 10C (2000 mA/g), the first discharge specific capacity is 144.5mAh/g, after 10 cycles, the discharge specific capacity is still maintained at 142.5mAh/g, the capacity retention rate is 98.6%, and the rate capability is excellent.
Vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material embodiment 3
The vanadium pentoxide coats the core-shell structure gradient nickel-cobalt-manganese positive electrode material, and the vanadium pentoxide coating coats the core-shell structure gradient nickel-cobalt-manganese positive electrode materialForming; the chemical formula of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material is V2O5@ LiNi0.75Co0.12Mn0.13O2(ii) a The core-shell structure gradient nickel-cobalt-manganese cathode material is prepared from a precursor Ni of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in reference example 10.75Co0.12Mn0.13(OH)2Mixed lithium is sintered; the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material is spherical particles with the average particle size of 3.9 mu m; the thickness of the coating layer of the vanadium pentoxide is 8nm, and the mass percent of the vanadium pentoxide is 3.5%; the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the contents of manganese, cobalt and vanadium are uniformly distributed in the center of the core-shell structure particles and the shell layer; the core of the core-shell structure gradient nickel-cobalt-manganese cathode material is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking hydroxide precipitation of nickel-cobalt-manganese as a precursor, and the shell layer is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking nickel-cobalt-manganese carbonate as a precursor; the diameter of the inner core is 3.5 μm, and the thickness of the shell layer is 0.4 μm.
Embodiment 3 of the method for preparing vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material
(1) 1g (0.01029 mol) of precursor Ni of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in reference example 10.75Co0.12Mn0.13(OH)2Aging at 70 ℃ and a rotation speed of 600r/min for 8h, filtering, washing with deionized water, and drying at 60 ℃ for 12h to obtain an aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor;
(2) adding 0.399g (0.0054 mol) of lithium carbonate (the molar ratio of the lithium element to the sum of the mole numbers of the nickel, cobalt and manganese elements is 1.05: 1) into the precursor of the aged core-shell structure gradient nickel-cobalt-manganese positive electrode material obtained in the step (1), grinding for 5min at 900r/min, presintering for 3h at 500 ℃, and sintering for 16h at 700 ℃ to obtain the core-shell structure gradient nickel-cobalt-manganese positive electrode material;
(3) mixing 1g of the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in the step (2) with 0.0432g (0.00037 mol) of ammonium metavanadate in 40mL of glycol solution, carrying out ultrasonic treatment for 4h at 40kHz, heating and stirring at 60 ℃ and at the rotating speed of 100r/min for reaction until the mixture is evaporated to dryness, and obtaining mixed powder;
(4) carrying out heat treatment on the mixed powder obtained in the step (3) for 4 hours at 450 ℃ in an oxygen atmosphere to obtain a vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material V2O5@ LiNi0.75Co0.12Mn0.13O2。
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The nickel-cobalt-manganese ternary cathode material is a pure-phase nickel-cobalt-manganese ternary cathode material, and the crystal structure of the nickel-cobalt-manganese ternary cathode material is not changed after vanadium pentoxide is coated.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The spherical particles with the particle size of 3.9 mu m are uniform in appearance.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The outer layer of the particle is provided with a relatively uniform coating layer with the thickness of 8 nm.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2The diameter of the inner core is 3.5 mu m, the thickness of the shell layer is 0.4 mu m, the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the contents of manganese, cobalt and vanadium are uniformly distributed in the center of the core-shell structure particles and the shell layer.
Assembling the battery: the same as in example 1.
As shown in fig. 10, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the present invention2O5@ LiNi0.75Co0.12Mn0.13O2The specific first discharge capacity at 0.1C (20 mA/g) rate was 192 mAh/g.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2Under the multiplying power of 1C (mA/g), after circulating for 100 circles, the specific discharge capacity is still kept at 155mAh/g, the capacity retention rate is 86.7 percent, and the excellent circulating performance is shown.
Through detection, the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material V obtained in the embodiment of the invention2O5@ LiNi0.75Co0.12Mn0.13O2Under the high current density of 10C (2000 mA/g), the first discharge specific capacity is 142.8mAh/g, after 10 cycles, the discharge specific capacity is still kept at 140.5mAh/g, the capacity retention rate is 98.4%, and the rate capability is excellent.
Comparative example 1
This comparative example differs from example 1 only in that: the steps (3) and (4) are removed, and the core-shell structure gradient nickel-cobalt-manganese cathode material is obtained, and the same as the embodiment 1.
Through detection, the core-shell structure gradient nickel-cobalt-manganese cathode material LiNi obtained by the comparative example0.75Co0.12Mn0.13O2The specific first discharge capacity at a current density of 0.1C (20 mA/g) was 199 mAh/g.
As shown in FIG. 11, the core-shell structure gradient Ni-Co-Mn positive electrode material LiNi obtained in the comparative example0.75Co0.12Mn0.13O2Under the multiplying power of 1C (mA/g), after 100 cycles, the discharge specific capacity is only 142mAh/g, and the capacity retention rate is only 78%.
Through detection, the core-shell structure gradient nickel-cobalt-manganese cathode material LiNi obtained by the comparative example0.75Co0.12Mn0.13O2Under the high current density of 10C (2000 mA/g), the first discharge specific capacity is 141mAh/g, and the capacity retention rate is only 70.8%.
As can be seen from the above, the vanadium pentoxide is not coated, and the improvement of the cycle performance and the rate capability of the core-shell structure gradient nickel-cobalt-manganese cathode material is greatly influenced.

Claims (29)

1. A vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material is characterized in that: the core-shell structure gradient nickel-cobalt-manganese cathode material is coated by a vanadium pentoxide coating layer; the chemical formula of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material is V2O5@ LiNixCoyMn(1-x-y)O2Wherein x is more than or equal to 0.5 and less than or equal to 0.85, y is more than or equal to 0.05 and less than or equal to 0.4, and 1-x-y is more than or equal to 0; the core-shell structure gradient nickel-cobalt-manganese cathode material is obtained by sintering a core-shell structure gradient nickel-cobalt-manganese cathode material precursor mixed with lithium; the thickness of the vanadium pentoxide coating layer is 3-10 nm, and the mass percentage of vanadium pentoxide is 2-7%; the nickel content is gradually reduced from the center of the core-shell structure gradient nickel-cobalt-manganese cathode material to the surface of the shell layer, and the contents of manganese, cobalt and vanadium are uniformly distributed in the center of the core-shell structure particles and the shell layer;
the preparation method of the vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material comprises the following steps:
(1) aging, filtering, washing and drying the precursor of the core-shell structure gradient nickel-cobalt-manganese cathode material to obtain an aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor;
(2) adding a lithium source into the aged core-shell structure gradient nickel-cobalt-manganese cathode material precursor obtained in the step (1), grinding, pre-sintering and sintering to obtain a core-shell structure gradient nickel-cobalt-manganese cathode material;
(3) mixing the core-shell structure gradient nickel-cobalt-manganese cathode material obtained in the step (2) with a vanadium source in an alcohol solution, performing ultrasonic treatment, heating, stirring and reacting until the mixture is evaporated to dryness, and obtaining mixed powder;
(4) carrying out heat treatment on the mixed powder obtained in the step (3) in an oxygen-containing atmosphere to obtain a vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material;
in the step (2), the rotation speed of the grinding is 600-1000 r/min, and the time is 5-10 min;
in the step (3), the molar ratio of vanadium element in the vanadium source to the sum of the mole numbers of nickel, cobalt and manganese elements in the core-shell structure gradient nickel-cobalt-manganese cathode material is 0.01-0.10: 1; the vanadium source is one or two of vanadium acetylacetonate or vanadyl acetylacetonate; the volume-mass ratio of the alcoholic solution to the total mass of the core-shell structure gradient nickel-cobalt-manganese cathode material and the vanadium source is 10-60: 1; the heating and stirring reaction temperature is 40-50 ℃, and the stirring speed is 100-200 r/min.
2. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1, which is characterized in that: the vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese positive electrode material is spherical particles with the average particle size of 3-12 mu m; the core of the core-shell structure gradient nickel-cobalt-manganese cathode material is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking hydroxide precipitation of nickel-cobalt-manganese as a precursor, and the shell layer is nickel-cobalt lithium manganate obtained by mixing and sintering lithium by taking nickel-cobalt-manganese carbonate as a precursor; the diameter of the inner core is 2.5-9.0 mu m, and the thickness of the shell layer is 0.3-3.0 mu m.
3. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1 or 2, characterized in that: the preparation method of the core-shell structure gradient nickel-cobalt-manganese cathode material precursor comprises the following steps:
1) pumping the low-nickel-content nickel-cobalt-manganese solution into a container filled with the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution, stirring, simultaneously pumping the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution continuously pumped into the reaction kettle filled with the ammonia solution, simultaneously adjusting the ammonia concentration of the reaction system by using the ammonia water, adjusting the pH value of the reaction system by using a hydroxide precipitator solution, stirring for coprecipitation reaction until the average particle size of particles grows to 2.5-9.0 mu m, obtaining a precursor nuclear material, continuing to perform the above operation, only replacing the hydroxide precipitator solution by a carbonate precipitator solution for adjusting the pH value of the reaction system, stirring for coprecipitation reaction until the low-nickel-content nickel-cobalt-manganese solution and the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution are completely fed, and obtaining a solution containing a core-shell material; in the low-nickel-content nickel-cobalt-manganese solution, the concentration of metal ions is 1-3 mol/L, and the molar percentage of Ni ions in the total metal ions is 40-70%; in the high nickel content nickel cobalt or nickel cobalt manganese solution, the concentration of metal ions is 1-3 mol/L, and the molar percentage of Ni ions in the total metal ions is 60-90%; in the same reaction system, the nickel content of the nickel-cobalt-manganese solution with low nickel content is lower than that of the nickel-cobalt or nickel-cobalt-manganese solution with high nickel content;
2) stirring the solution containing the precursor core-shell material obtained in the step 1), aging, filtering, washing and drying to obtain the core-shell structure gradient nickel-cobalt-manganese cathode material precursor.
4. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 3, wherein: in the step 1), the feeding speed of the low-nickel-content nickel-cobalt-manganese solution is 20-60 mL/h, and the feeding speed of the high-nickel-content nickel-cobalt or nickel-cobalt-manganese solution continuously pumped into the low-nickel-content nickel-cobalt-manganese solution is 50-100 mL/h; in the nickel-cobalt-manganese solution with low nickel content, the mole percentage of Co ions in the total metal ions is 10-40%, the mole percentage of Mn ions in the total metal ions is 20-50%, and the total of Ni ions, Co ions and Mn ions is 100%; in the high nickel content nickel cobalt or nickel cobalt manganese solution, the mole percentage of Co ions in the total metal ions is 10-40%, the mole percentage of Mn ions in the total metal ions is 0-30%, and the total of Ni ions, Co ions and Mn ions is 100%; the volume ratio of the ammonia water solution, the nickel-cobalt-manganese solution with low nickel content to the nickel-cobalt or nickel-cobalt-manganese solution with high nickel content in the reaction kettle is (0.1-10): 0.8-1.2): 1; the molar concentration of the ammonia water solution is 0.3-0.5 mol/L; adjusting the concentration of ammonia water in the reaction system to be 0.3-0.5 mol/L by using ammonia water; the mass concentration of the ammonia water for adjusting the ammonia water concentration of the reaction system is 25-28%; regulating the pH value of the reaction system to be 10.5-11.5 by using a hydroxide precipitant solution; the molar concentration of the hydroxide precipitant solution is 5-10 mol/L; the hydroxide precipitator is one or more of sodium hydroxide, potassium hydroxide or lithium hydroxide; adjusting the pH value of the reaction system to be 8.5-10.5 by using a carbonate precipitant solution; the molar concentration of the carbonate precipitant solution is 0.5-1.5 mol/L; the carbonate precipitator is one or more of sodium carbonate, potassium carbonate, lithium carbonate, sodium bicarbonate or potassium bicarbonate; in the coprecipitation reaction for generating the precursor core material and the precursor core-shell layer material, the stirring speed is 600-1200 r/min, and the temperature is 50-70 ℃; the low nickel content nickel-cobalt-manganese solution is a mixed solution of soluble nickel salt, soluble cobalt salt and soluble manganese salt; the high nickel content nickel-cobalt solution is a mixed solution of soluble nickel salt and soluble cobalt salt, and the high nickel content nickel-cobalt-manganese solution is a mixed solution of soluble nickel salt, soluble cobalt salt and soluble manganese salt; the soluble nickel salt is one or more of nickel sulfate, nickel nitrate, nickel acetate or nickel chloride; the soluble cobalt salt is one or more of cobalt sulfate, cobalt nitrate, cobalt acetate or cobalt chloride; the soluble manganese salt is one or more of manganese sulfate, manganese nitrate, manganese acetate or manganese chloride; in the step 2), the stirring speed is 400-800 r/min; the aging temperature is 50-80 ℃, and the aging time is 5-15 h; the drying temperature is 50-100 ℃, and the drying time is 5-15 h.
5. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1 or 2, characterized in that: in the step (1), the aging temperature is 50-80 ℃, the rotation speed during aging is 600-1200 r/min, and the time is 5-15 h; the drying temperature is 50-100 ℃, and the drying time is 5-15 h.
6. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 3, wherein: in the step (1), the aging temperature is 50-80 ℃, the rotation speed during aging is 600-1200 r/min, and the time is 5-15 h; the drying temperature is 50-100 ℃, and the drying time is 5-15 h.
7. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 4, wherein: in the step (1), the aging temperature is 50-80 ℃, the rotation speed during aging is 600-1200 r/min, and the time is 5-15 h; the drying temperature is 50-100 ℃, and the drying time is 5-15 h.
8. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1 or 2, characterized in that: in the step (2), the molar ratio of the lithium element in the lithium source to the sum of the mole numbers of the nickel, cobalt and manganese elements in the precursor of the core-shell structure gradient nickel-cobalt-manganese cathode material is 1.01-1.07: 1; the lithium source is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate or lithium acetate and hydrates thereof.
9. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 3, wherein: in the step (2), the molar ratio of the lithium element in the lithium source to the sum of the mole numbers of the nickel, cobalt and manganese elements in the precursor of the core-shell structure gradient nickel-cobalt-manganese cathode material is 1.01-1.07: 1; the lithium source is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate or lithium acetate and hydrates thereof.
10. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 4, wherein: in the step (2), the molar ratio of the lithium element in the lithium source to the sum of the mole numbers of the nickel, cobalt and manganese elements in the precursor of the core-shell structure gradient nickel-cobalt-manganese cathode material is 1.01-1.07: 1; the lithium source is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate or lithium acetate and hydrates thereof.
11. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 5, wherein: in the step (2), the molar ratio of the lithium element in the lithium source to the sum of the mole numbers of the nickel, cobalt and manganese elements in the precursor of the core-shell structure gradient nickel-cobalt-manganese cathode material is 1.01-1.07: 1; the lithium source is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate or lithium acetate and hydrates thereof.
12. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1 or 2, characterized in that: in the step (2), the pre-sintering temperature is 350-550 ℃, and the time is 3-6 h; the sintering temperature is 650-950 ℃, and the sintering time is 8-24 h.
13. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 3, wherein: in the step (2), the pre-sintering temperature is 350-550 ℃, and the time is 3-6 h; the sintering temperature is 650-950 ℃, and the sintering time is 8-24 h.
14. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 4, wherein: in the step (2), the pre-sintering temperature is 350-550 ℃, and the time is 3-6 h; the sintering temperature is 650-950 ℃, and the sintering time is 8-24 h.
15. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 5, wherein: in the step (2), the pre-sintering temperature is 350-550 ℃, and the time is 3-6 h; the sintering temperature is 650-950 ℃, and the sintering time is 8-24 h.
16. The vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 8, wherein: in the step (2), the pre-sintering temperature is 350-550 ℃, and the time is 3-6 h; the sintering temperature is 650-950 ℃, and the sintering time is 8-24 h.
17. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1 or 2, characterized in that: in the step (3), the alcoholic solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol; the frequency of the ultrasonic wave is 30-40 kHz, and the time is 4-8 h.
18. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 3, wherein: in the step (3), the alcoholic solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol; the frequency of the ultrasonic wave is 30-40 kHz, and the time is 4-8 h.
19. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 4, wherein: in the step (3), the alcoholic solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol; the frequency of the ultrasonic wave is 30-40 kHz, and the time is 4-8 h.
20. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 5, wherein: in the step (3), the alcoholic solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol; the frequency of the ultrasonic wave is 30-40 kHz, and the time is 4-8 h.
21. The vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 8, wherein: in the step (3), the alcoholic solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol; the frequency of the ultrasonic wave is 30-40 kHz, and the time is 4-8 h.
22. The vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 12, wherein: in the step (3), the alcoholic solution is one or more of absolute ethyl alcohol, ethylene glycol or methanol; the frequency of the ultrasonic wave is 30-40 kHz, and the time is 4-8 h.
23. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 1 or 2, characterized in that: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
24. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 3, wherein: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
25. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 4, wherein: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
26. The vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 5, wherein: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
27. The vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 8, wherein: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
28. The vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 12, wherein: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
29. The vanadium pentoxide coated core-shell structure gradient nickel-cobalt-manganese cathode material according to claim 17, wherein: in the step (4), the temperature of the heat treatment is 300-600 ℃, and the time is 4-8 h; the oxygen-containing atmosphere is one or more of air atmosphere, oxygen atmosphere or ozone atmosphere.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11855285B2 (en) * 2019-04-19 2023-12-26 Central South University Full-gradient nickel cobalt manganese positive electrode material, ruthenium oxide coated material and preparation method thereof

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102637871A (en) * 2012-04-19 2012-08-15 中南大学 A kind of preparation method of lithium ion active oxide V2O5 coated lithium ion positive electrode material
CN102637866A (en) * 2012-04-25 2012-08-15 中南大学 Method for preparing lithium ion battery anode material with concentration gradient
KR20170102293A (en) * 2014-12-31 2017-09-08 베이징 이스프링 머티리얼 테크놀로지 컴퍼니 리미티드 Multicomponent materials having a classification structure for lithium ion batteries, a method for manufacturing the same, an anode of a lithium ion battery and a lithium ion battery
CN108793268A (en) * 2018-06-19 2018-11-13 中南大学 Nucleocapsid gradient nickel-cobalt-manganternary ternary anode material presoma and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102637871A (en) * 2012-04-19 2012-08-15 中南大学 A kind of preparation method of lithium ion active oxide V2O5 coated lithium ion positive electrode material
CN102637866A (en) * 2012-04-25 2012-08-15 中南大学 Method for preparing lithium ion battery anode material with concentration gradient
KR20170102293A (en) * 2014-12-31 2017-09-08 베이징 이스프링 머티리얼 테크놀로지 컴퍼니 리미티드 Multicomponent materials having a classification structure for lithium ion batteries, a method for manufacturing the same, an anode of a lithium ion battery and a lithium ion battery
CN108793268A (en) * 2018-06-19 2018-11-13 中南大学 Nucleocapsid gradient nickel-cobalt-manganternary ternary anode material presoma and preparation method thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11855285B2 (en) * 2019-04-19 2023-12-26 Central South University Full-gradient nickel cobalt manganese positive electrode material, ruthenium oxide coated material and preparation method thereof

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