CN113184923A - Preparation method of niobium modified lithium-rich manganese-based material, positive electrode material and lithium ion battery - Google Patents
Preparation method of niobium modified lithium-rich manganese-based material, positive electrode material and lithium ion battery Download PDFInfo
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Abstract
The invention relates to a preparation method of a niobium modified lithium-rich manganese-based material, a positive electrode material and a lithium ion battery, wherein the preparation method of the niobium modified lithium-rich manganese-based material comprises the following steps: obtaining a nickel-cobalt-manganese precursor; mixing and presintering the nickel-cobalt-manganese precursor with a first part of lithium salt, cooling, and then mixing with a second part of lithium salt and a niobium-containing compound under a vacuum state to obtain a mixture; and carrying out normal-pressure high-temperature heat treatment on the mixture to obtain the niobium modified lithium-rich manganese-based material. The lithium-rich manganese-based material prepared by the method is applied to a positive electrode material and a lithium ion battery, and can obviously improve the initial efficiency and the cycle stability of the material and inhibit the oxygen precipitation of the structure and the voltage attenuation. The preparation method is simple, has obvious modification effect and has the potential of large-scale application.
Description
Technical Field
The invention belongs to the field of composite materials, and particularly relates to a preparation method of a niobium modified lithium-rich manganese-based material, a positive electrode material and a lithium ion battery.
Background
In recent years, the energy density of the lithium ion battery is promoted to be continuously improved due to explosive growth of the new energy automobile market and increase of the automobile endurance mileage, and the anode material is a core factor for restricting the specific capacity and the energy density of the lithium ion battery. The lithium-rich manganese-based positive electrode material is praised by researchers at home and abroad as one of the most promising positive electrode materials of the next generation, and is one of the key materials for realizing the 350Wh/kg target of the single battery cell in 2025. The lithium-rich manganese-based positive electrode material has the advantages of high specific capacity (more than 280mAh/g), high working voltage (more than 3.6V), low cost, environmental friendliness and the like, so that the lithium-rich manganese-based positive electrode material is widely concerned. However, Li in the transition metal layer during first cycle charging+With Li2The irreversible process after the elimination of the form of O causes a low coulombic efficiency. Due to Li2MnO3The phase has a low ionic/electronic conductivity, so that the lithium-rich manganese-based material has poor rate capability. The more key to the commercial process of the lithium-rich manganese base is the voltage attenuation problem and is also a hot problem for research in the scientific research community and the academic community at present. It is believed that the voltage decay is related to the transition of the transition metal TM and the structural phase change. TM moves from octahedral position to tetrahedral gap of metal lithium layer to occupy lithium octahedral position, and material gradually moves from layered structure in circulation processStep by step, the crystal is transited to a spinel structure.
Research is carried out on niobium doping or modification of the lithium-rich manganese-based material, and after the niobium doping or modification, the first efficiency of the material can be improved to a certain degree and voltage attenuation can be inhibited. In the related technology, a research is carried out on mixing a lithium-rich manganese-based material with a niobium carboxylic acid derivative, a lithium salt and other substances by a wet method, and then carrying out high-temperature heat treatment. In addition, studies have been made to combine lithium-rich manganese-based precursors with LiNbO3Or Nb2O5And Al2O3And (3) mixing by a wet method, evaporating to dryness in a water bath, and then carrying out high-temperature heat treatment to obtain the modified lithium-rich manganese-based material. The method also has the problems of price and environmental protection of the organic solvent, and is not beneficial to cost reduction due to a plurality of high-energy consumption process steps such as water bath evaporation, forced air drying, high-temperature heat treatment and the like.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a preparation method of a niobium modified lithium-rich manganese-based material, the lithium-rich manganese-based material prepared by the method can effectively inhibit voltage attenuation and improve first-time efficiency and rate capability, and the preparation method is simple in process, low in energy consumption, environment-friendly and high in large-scale industrialization value.
The second aspect of the present invention provides a positive electrode material.
The third aspect of the invention also provides a lithium ion battery.
According to a first aspect of the invention, a preparation method of a niobium modified lithium-rich manganese-based material is provided, which comprises the following steps: obtaining a nickel-cobalt-manganese precursor; mixing and presintering the nickel-cobalt-manganese precursor with a first part of lithium salt, cooling, and then mixing with a second part of lithium salt and a niobium-containing compound under a vacuum state to obtain a mixture; and carrying out normal-pressure high-temperature heat treatment on the mixture to obtain the niobium modified lithium-rich manganese-based material.
The preparation method of the lithium-rich manganese-based composite material provided by the embodiment of the invention at least has the following beneficial effects: the method comprises the steps of mixing a nickel-cobalt-manganese precursor with a part of lithium salt, then presintering for a period of time to form a certain layered structure, cooling, then mixing with a second part of lithium salt and a niobium-containing compound, and carrying out high-temperature heat treatment at normal pressure to obtain the niobium-modified lithium-rich manganese-based material. And in the heat treatment stage, niobium is doped into the surface of the material, and redundant niobium reacts with lithium salt or residual alkali on the surface of the lithium-rich manganese-based material to generate a lithium niobate coating layer. Because the Nb-O bond energy is higher than TM-O bond energy (TM represents transition metal), under high voltage, Nb doping can effectively inhibit oxygen precipitation, relieve voltage attenuation and improve cycle stability; the lithium niobate coating can reduce the corrosion of the electrolyte on the surface of the lithium-rich manganese-based material, reduce the dissolution of the transition metal TM, reduce the oxidation of the electrolyte under high voltage and improve the cycle stability. The preparation method has the advantages of short period, no need of adopting multiple steps of long time consumption such as evaporation to dryness, drying and the like, no need of using a large amount of organic solvent or complexing agent, low cost, environmental protection, simple preparation method, obvious modification effect and potential for large-scale application.
According to some embodiments of the invention, the pre-sintering temperature is 300-600 ℃, the pre-sintering time is 2-8 h, and the temperature rise rate is 2-8 ℃/min; preferably, the pre-sintering temperature is 400-550 ℃, the pre-sintering time is 4-6 h, and the heating rate is 3-5 ℃/min.
In some embodiments, the pre-firing temperature is any one of 300 ℃, 350 ℃, 380 ℃, 400 ℃, 450 ℃, 480 ℃, 500 ℃, 520 ℃ or 550 ℃.
The pre-sintering process is controlled within the range, a part of layered structure can be formed in advance, doping of niobium element in the subsequent normal-pressure high-temperature heat treatment stage is facilitated, and the uniformity of coating of the niobium-containing compound on the surface of the material is facilitated.
According to some embodiments of the invention, the mass ratio of the first part of lithium salt to the second part of lithium salt is 1: (1-9).
By controlling the mass ratio of the first part of lithium salt to the second part of lithium salt to be in the above range, if the amount of lithium salt added in the first step is too small, the preformed layered structure is incomplete, which is not beneficial to the subsequent niobium modification; if the lithium salt is added too much in the first step, the effect of sintering step by step cannot be achieved, and if the lithium salt is too little in the second step, the modification of the material by the niobium-containing compound is also not facilitated.
According to some embodiments of the invention, the normal-pressure high-temperature heat treatment is divided into two stages, the temperature of the first stage heat treatment is 350-650 ℃, the heating rate is 1-10 ℃/min, the sintering time is 2-8 h, the sintering temperature of the second stage is 750-1000 ℃, the heating rate is 1-10 ℃/min, and the sintering time is 6-24 h.
It should be noted that the two-stage sintering process adopted by the invention, combined with the pre-sintering process, can further facilitate the formation of a uniform coating layer on the surface of the lithium-rich manganese-based material by the niobium-containing compound. The layered structure and the crystallinity of the material can be more complete by two-step sintering, because the decomposition temperature of a plurality of lithium salts is distributed between 350 ℃ and 650 ℃, the temperature is kept in the temperature range for a period of time, the decomposition reaction of the lithium salts is facilitated, and the sintering is promoted.
In some embodiments of the present invention, the preparation method of the obtained nickel-cobalt-manganese precursor includes multiple methods, such as a coprecipitation method, a sol-gel method, a solid phase method, a hydrothermal method, and the like, and different preparation methods can be used according to different application scenarios, while the coprecipitation method is generally used in current industrial production.
According to some embodiments of the invention, the nickel cobalt manganese precursor is prepared by a co-precipitation method, the co-precipitation method comprising the steps of: dissolving metal salt containing nickel, cobalt and manganese in a first solvent to prepare a metal mixed solution; and mixing the metal mixed solution and the precipitant solution, carrying out coprecipitation reaction, and aging, separating and drying to obtain the nickel-cobalt-manganese precursor.
According to some embodiments of the invention, the metal salt of nickel comprises at least one of nickel sulfate, nickel nitrate, nickel chloride, and nickel acetate, the metal salt of cobalt comprises cobalt sulfate, cobalt nitrate, cobalt chloride, and cobalt acetate, and the metal salt of manganese comprises at least one of manganese sulfate, manganese nitrate, manganese chloride, and manganese acetate.
According to some embodiments of the invention, the precipitant in the precipitant solution comprises at least one of sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate.
According to some embodiments of the invention, the first solvent is at least one of deionized water, ethanol, ethylene glycol, propanol, isopropanol, butanetriol, acetone.
According to some embodiments of the invention, the precipitant solution may be formed by dissolving the precipitant in a second solvent. Further, the second solvent may be at least one of deionized water, ethanol, ethylene glycol, propanol, isopropanol, butanetriol and acetone.
According to some embodiments of the invention, in the coprecipitation reaction, the pH value is adjusted to 7.5-11.5, and the coprecipitation reaction is performed at 40-75 ℃ in a protective atmosphere, wherein the reaction time is 6-36 h.
According to some embodiments of the invention, the protective atmosphere comprises at least one of argon, nitrogen, helium, neon.
According to some embodiments of the invention, the molar ratio of the nickel cobalt manganese precursor to the niobium-containing compound is 100: (0.1-5); and/or the molar sum of nickel, cobalt and manganese metals in the precursor is as follows: the molar ratio of the first part of lithium salt to the second part of lithium salt is 1: 1.2-1.7.
In some embodiments, the molar ratio of the nickel-cobalt-manganese precursor to the niobium-containing compound may be any one of 100: 0.1, 100: 0.5, 100: 1, 100: 1.5, 100: 2, 100: 2.5, 100: 3, 100: 3.5, 100: 4, 100: 4.5, or 100: 5, etc.
It should be noted that, when the molar ratio of the nickel-cobalt-manganese precursor to the niobium-containing compound is controlled to 100: (0.1-5), niobium functions as a modifier, and when the ratio is too low, the modification effect is not significant, but the niobium compound is inactive and cannot provide a capacity, and when the ratio is too high, the specific capacity is reduced and the cost is increased.
According to some embodiments of the invention, the niobium-containing compound comprises at least one of niobium oxalate, ammonium niobium oxalate, niobium ethoxide, niobium pentoxide, lithium niobate; and/or, the lithium salt comprises at least one of lithium hydroxide, lithium carbonate, lithium acetate, lithium nitrate and lithium ethoxide.
According to some embodiments of the invention, the molar concentration of the total metal of nickel, cobalt and manganese in the metal mixed solution is 0.5-3 mol/L, and/or the molar concentration of the precipitant in the precipitant solution is 0.5-4 mol/L.
According to some embodiments of the present invention, the vacuum mixing process includes adding the pre-sintered and cooled product, the second part of lithium salt and the niobium-containing compound into a ball milling tank, vacuumizing, and performing mechanical ball milling to uniformly mix the pre-sintered and cooled product, the second part of lithium salt and the niobium-containing compound. It is understood that the evacuation operation is selected depending on the type of the niobium-containing compound. Specifically, some niobium-containing compounds are easily hydrolyzed, such as niobium ethoxide, which reduces the activity of the raw material and is not easily dispersed uniformly with the material after being directly exposed to air, so that a vacuum-pumping operation is required; and for the niobium-containing compound which is not easy to hydrolyze, the vacuum-pumping operation is not needed.
According to some embodiments of the invention, the rotation speed of the ball milling is 50-2000 r/min, and the ball milling time is 0.5-12 h.
In a second aspect of the invention, a cathode material is provided, which comprises the niobium modified lithium-rich manganese-based material prepared by the above preparation method of the niobium modified lithium-rich manganese-based material.
According to the positive electrode material disclosed by the embodiment of the invention, the lithium-rich manganese-based material obtained by modifying niobium is adopted, and niobium enters the crystal lattice on the surface of the material after the niobium-containing compound is modified, so that the structure of the lithium-rich manganese-based material can be stabilized, the cycle stability is improved, the oxygen release is reduced, a lithium niobate coating layer can be formed on the surface of the lithium-rich manganese-based material, and when the niobium-modified lithium-rich manganese-based material is used as a positive electrode active material, the first efficiency and the cycle stability of the material can be improved, and the oxygen precipitation and the voltage attenuation of the structure can be inhibited.
In a third aspect of the present invention, there is provided a lithium ion battery comprising a positive electrode, a negative electrode and a separator, wherein the positive electrode comprises the positive electrode material described above.
According to the lithium ion battery provided by the embodiment of the invention, the niobium-modified lithium-rich manganese-based material is adopted, so that the initial efficiency of the battery can be improved, and the cycle stability of the lithium ion battery can be improved.
Drawings
The invention is further described with reference to the following figures and examples, in which:
fig. 1 is SEM images of lithium-rich manganese-based positive electrode materials prepared in example of the present invention and comparative example 1 (wherein, a) represents the lithium-rich manganese-based positive electrode material prepared in comparative example 1, and b) represents the lithium-rich manganese-based positive electrode material prepared in example 1);
fig. 2 is a graph of the cycling performance of the button cells prepared in example 1 of the present invention and comparative examples 1-2 at room temperature of 0.5C.
Detailed Description
The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.
In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Specific examples of the present invention are described in detail below.
Example 1
The preparation process of the lithium-rich manganese-based cathode material comprises the following steps:
(1) weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 1: 4, dissolving in deionized water to prepare a 2mol/L metal salt mixed solution, and dissolving a sodium carbonate precipitator in the deionized water to form a 2mol/L solution;
(2) pumping the metal salt mixed solution and a sodium carbonate solution into a reaction base solution, adjusting the pH of the solution to 8.5 by using ammonia water, carrying out coprecipitation reaction for 24 hours at 55 ℃ under the protection of argon atmosphere, and carrying out aging, solid-liquid separation and drying to obtain Ni1/6Co1/6Mn4/ 6CO3A precursor;
(3) mixing 5g of the precursor prepared in the step (2) with 1.1364g (40 wt% of lithium salt) of lithium hydroxide monohydrate, heating to 525 ℃ at a heating rate of 3 ℃/min, preserving heat for 4h, cooling along with a furnace, and uniformly mixing with 1.7045g (60 wt% of lithium salt) of lithium hydroxide monohydrate and 0.2314g of niobium oxalate under a vacuum condition, wherein the ball milling rate is 250r/min, and the ball milling time is 2 h;
(4) and (4) heating the mixture prepared in the step (3) to 500 ℃ at a speed of 3 ℃/min, preserving heat for 5h, heating to 850 ℃ at a speed of 5 ℃/min, and preserving heat for 12h to obtain the niobium modified lithium-rich manganese-based positive electrode material.
The preparation process of the button type lithium ion battery comprises the following steps:
and (2) taking NMP (N-methyl pyrrolidone) as a solvent, homogenizing the prepared lithium-rich manganese-based positive electrode material, PVDF (polyvinylidene fluoride) and SP (conductive carbon black) according to the mass ratio of 90: 5, coating the obtained mixture on a current collector Al foil, drying to obtain a positive electrode piece, assembling the positive electrode piece and a metal lithium piece into a button cell, and testing the electrochemical performance of the button cell.
In addition, the prepared lithium-rich manganese-based positive electrode material, a negative electrode, an electrolyte, a diaphragm, an aluminum plastic film, a tab and the like can be assembled into a full cell according to a certain process, and the full cell can be finally applied to electric automobiles.
Example 2
The preparation process of the lithium-rich manganese-based cathode material comprises the following steps:
(1) weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 1: 4, dissolving in deionized water to prepare a 2mol/L metal salt mixed solution, and dissolving a sodium carbonate precipitator in the deionized water to form a 2mol/L solution;
(2) pumping the metal salt mixed solution and a sodium carbonate solution into a reaction base solution, adjusting the pH of the solution to 8.5 by using ammonia water, carrying out coprecipitation reaction for 24 hours at 55 ℃ under the protection of argon atmosphere, and carrying out aging, solid-liquid separation and drying to obtain Ni1/6Co1/6Mn4/ 6CO3A precursor;
(3) mixing 5g of the precursor prepared in the step (2) with 1.4204g (50 wt% of lithium salt) of lithium hydroxide monohydrate, heating to 450 ℃ at a heating rate of 3 ℃/min, preserving heat for 5h, cooling along with a furnace, and then uniformly mixing 1.4204g (50 wt% of lithium salt) of lithium hydroxide monohydrate and 0.3471g of niobium oxalate under a vacuum condition, wherein the ball milling rate is 250r/min, and the ball milling time is 2 h;
(4) and (4) heating the mixture prepared in the step (3) to 500 ℃ at a speed of 3 ℃/min, preserving heat for 5h, heating to 875 ℃ at a speed of 5 ℃/min, and preserving heat for 12h to obtain the niobium modified lithium-rich manganese-based positive electrode material.
The preparation process of the button type lithium ion battery comprises the following steps:
and (3) homogenizing the prepared lithium-rich manganese-based composite positive electrode material, PVDF and SP according to the mass ratio of 90: 5 by taking NMP as a solvent, coating the mixture on a current collector Al foil, drying to obtain a positive electrode piece, assembling the positive electrode piece and a metal lithium piece into a button cell, and testing the electrochemical performance of the button cell.
In addition, the prepared lithium-rich manganese-based composite positive electrode material, a negative electrode, an electrolyte, a diaphragm, an aluminum-plastic film, a tab and the like can be assembled into a full cell according to a certain process, and the full cell can be finally applied to electric automobiles.
Example 3
The preparation process of the lithium-rich manganese-based cathode material comprises the following steps:
(1) weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 1: 4, dissolving in deionized water to prepare a 2mol/L metal salt mixed solution, and dissolving a sodium carbonate precipitator in the deionized water to form a 2mol/L solution;
(2) pumping the mixed solution of the metal salt and the sodium carbonate solution into a reaction tankAdjusting the pH of the solution to 8.5 with ammonia water in the base solution, carrying out coprecipitation reaction for 24 hours at 55 ℃ under the protection of argon atmosphere, aging, carrying out solid-liquid separation, and drying to obtain Ni1/6Co1/6Mn4/ 6CO3A precursor;
(3) mixing 5g of the precursor prepared in the step (2) with 0.8522g (30 wt% of lithium salt) of lithium hydroxide monohydrate, heating to 450 ℃ at a heating rate of 3 ℃/min, preserving heat for 5h, cooling along with a furnace, and then uniformly mixing 1.9886g (70 wt% of lithium salt) of lithium hydroxide monohydrate and 0.2314g of niobium oxalate under a vacuum condition, wherein the ball milling rate is 200r/min, and the ball milling time is 1.5 h;
(4) and (4) heating the mixture prepared in the step (3) to 500 ℃ at a speed of 3 ℃/min, preserving heat for 5h, heating to 900 ℃ at a speed of 5 ℃/min, and preserving heat for 10h to obtain the niobium modified lithium-rich manganese-based composite positive electrode material.
The preparation process of the button type lithium ion battery comprises the following steps:
and (3) homogenizing the prepared lithium-rich manganese-based composite positive electrode material, PVDF and SP according to the mass ratio of 90: 5 by taking NMP as a solvent, coating the mixture on a current collector Al foil, drying to obtain a positive electrode piece, assembling the positive electrode piece and a metal lithium piece into a button cell, and testing the electrochemical performance of the button cell.
In addition, the prepared lithium-rich manganese-based composite positive electrode material, a negative electrode, an electrolyte, a diaphragm, an aluminum-plastic film, a tab and the like can be assembled into a full cell according to a certain process, and the full cell can be finally applied to electric automobiles.
Comparative example 1
The preparation process of the lithium-rich manganese-based cathode material comprises the following steps:
(1) weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 1: 4, dissolving in deionized water to prepare a 2mol/L metal salt mixed solution, and dissolving a sodium carbonate precipitator in the deionized water to form a 2mol/L solution;
(2) pumping the metal salt mixed solution and a sodium carbonate solution into a reaction base solution, adjusting the pH of the solution to 8.5 by using ammonia water, carrying out coprecipitation reaction for 24 hours at 55 ℃ under the protection of argon atmosphere, and carrying out aging, solid-liquid separation and drying to obtain Ni1/6Co1/6Mn4/ 6CO3A precursor;
(3) adding 5g of the precursor prepared in the step (2) and 2.8409g of lithium hydroxide monohydrate into a ball milling tank, vacuumizing, and mechanically milling for 2 hours at a speed of 250r/min to uniformly mix the precursor and the lithium hydroxide monohydrate;
(4) and (4) heating the mixture prepared in the step (3) to 500 ℃ at a speed of 3 ℃/min, preserving heat for 5h, heating to 850 ℃ at a speed of 5 ℃/min, and preserving heat for 10h to obtain the lithium-rich manganese-based cathode material.
The preparation process of the button type lithium ion battery comprises the following steps:
and (3) homogenizing the prepared lithium-rich manganese-based composite positive electrode material, PVDF and SP according to the mass ratio of 90: 5 by taking NMP as a solvent, coating the mixture on a current collector Al foil, drying to obtain a positive electrode piece, assembling the positive electrode piece and a metal lithium piece into a button cell, and testing the electrochemical performance of the button cell.
In addition, the prepared lithium-rich manganese-based positive electrode material, a negative electrode, an electrolyte, a diaphragm, an aluminum plastic film, a tab and the like can be assembled into a full cell according to a certain process, and the full cell can be finally applied to an electric automobile.
Comparative example 2
The preparation process of the lithium-rich manganese-based cathode material comprises the following steps:
(1) weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 1: 4, dissolving in deionized water to prepare a 2mol/L metal salt mixed solution, and dissolving a sodium carbonate precipitator in the deionized water to form a 2mol/L solution;
(2) pumping the metal salt mixed solution and a sodium carbonate solution into a reaction base solution, adjusting the pH of the solution to 8.5 by using ammonia water, carrying out coprecipitation reaction for 24 hours at 55 ℃ under the protection of argon atmosphere, and carrying out aging, solid-liquid separation and drying to obtain a Ni1/6Co1/6Mn4/6CO3 precursor;
(3) 5g of the precursor prepared in the step (2), 2.8409g of lithium hydroxide monohydrate and 0.2314g of niobium oxalate are added into a ball milling tank and vacuumized, and then mechanical ball milling is carried out for 2 hours at a speed of 250r/min, so that the two are uniformly mixed;
(4) and (4) heating the mixture prepared in the step (3) to 500 ℃ at a speed of 3 ℃/min, preserving heat for 5h, heating to 850 ℃ at a speed of 5 ℃/min, and preserving heat for 10h to obtain the niobium modified lithium-rich manganese-based composite anode material.
The preparation process of the button type lithium ion battery comprises the following steps:
and (3) homogenizing the prepared lithium-rich manganese-based composite positive electrode material, PVDF and SP according to the mass ratio of 90: 5 by taking NMP as a solvent, coating the mixture on a current collector Al foil, drying to obtain a positive electrode piece, assembling the positive electrode piece and a metal lithium piece into a button cell, and testing the electrochemical performance of the button cell.
In addition, the prepared lithium-rich manganese-based composite positive electrode material, a negative electrode, an electrolyte, a diaphragm, an aluminum-plastic film, a tab and the like can be assembled into a full cell according to a certain process, and the full cell can be finally applied to electric automobiles.
SEM images of the lithium-rich manganese-based positive electrode materials prepared in example 1 and comparative example 1 are shown in fig. 1. Wherein, the pictures a) and b) are respectively the appearance pictures of the lithium-rich manganese-based material before and after niobium modification, so that the surface of the material after niobium modification is more compact and smooth. After niobium modification, niobium enters crystal lattices on the surface of the material, the structure of the material can be stabilized, the cycling stability of the material when the material is used as a positive electrode material is improved, oxygen release is reduced, a uniform lithium niobate coating layer is formed on the surface of the lithium-rich manganese-based material, and the coating layer can improve the primary efficiency and cycling stability of the positive electrode material and inhibit oxygen precipitation and voltage attenuation of the structure.
In addition, the cycling performance of the button cells prepared in example 1 and comparative examples 1-2 at room temperature of 0.5C is shown in fig. 2. As can be seen in FIG. 2, the material cycle stability after niobium modification is significantly improved, and the effect is particularly obvious in 50 weeks. After being cycled for 100 weeks at normal temperature by 0.5C, compared with comparative example 1 which is not modified by niobium, comparative example 2 is modified by a niobium-containing compound, the capacity retention rate is obviously better than that of comparative example 1, in comparative example 2, the capacity retention rate is improved to 92.76% from 87.56% which is not modified, but compared with example 1 which adopts pre-sintering of a part of lithium salt and a precursor (the capacity retention rate is 95.83%), the precursor of comparative example 2 is not subjected to the pre-sintering process, and the capacity retention rate is relatively lower. Therefore, the precursor and part of lithium salt are preburnt to form a part of layered structure in advance, which is beneficial to forming a uniform coating layer on the lithium-rich manganese-based material, thereby improving the cycling stability of the lithium-rich manganese-based material as the anode material.
TABLE 1 electrochemical data for each of the examples and comparative examples
Table 1 shows electrochemical properties of examples 1 to 3 and comparative examples 1 to 2, and it can be seen that the initial discharge specific capacity, the initial coulombic efficiency and the discharge voltage-sharing retention rate after 100 cycles of the discharge voltage-sharing retention rate of examples 1 to 3 after niobium modification are improved to different degrees compared with those of unmodified comparative example 1, and compared with comparative example 2, the initial coulombic efficiency of examples 1 to 3 is also better, and the initial discharge specific capacity and the discharge voltage-sharing retention rate after 100 cycles of the discharge voltage-sharing retention rate are also obviously improved, and in combination with fig. 2 and table 1, compared with a one-step lithium salt adding method, the niobium-modified lithium-rich manganese-based material prepared by the step-by-step addition method has better cycle stability, smaller voltage attenuation and higher initial efficiency. The electrochemical properties of the niobium-modified lithium-rich manganese-based material prepared by the two methods are obviously better than those of an unmodified material.
While the embodiments of the present invention have been described in detail with reference to the specific embodiments, the present invention is not limited to the embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.
Claims (10)
1. A preparation method of a niobium modified lithium-rich manganese-based material is characterized by comprising the following steps:
obtaining a nickel-cobalt-manganese precursor;
mixing and presintering the nickel-cobalt-manganese precursor with a first part of lithium salt, cooling, and then mixing with a second part of lithium salt and a niobium-containing compound under a vacuum state to obtain a mixture;
and carrying out normal-pressure high-temperature heat treatment on the mixture to obtain the niobium modified lithium-rich manganese-based material.
2. The preparation method according to claim 1, wherein the pre-sintering temperature is 300-600 ℃, the pre-sintering time is 2-8 h, and the temperature rise rate is 2-8 ℃/min; preferably, the pre-sintering temperature is 400-550 ℃, the pre-sintering time is 4-6 h, and the heating rate is 3-5 ℃/min.
3. The method according to claim 1, wherein the mass ratio of the first lithium salt to the second lithium salt is 1 (1-9).
4. The preparation method according to claim 1, wherein the normal-pressure high-temperature heat treatment is divided into two stages, the temperature of the first stage heat treatment is 350-650 ℃, the heating rate is 1-10 ℃/min, the sintering time is 2-8 h, the sintering temperature of the second stage is 750-1000 ℃, the heating rate is 1-10 ℃/min, and the sintering time is 6-24 h.
5. The preparation method of claim 1, wherein the nickel-cobalt-manganese precursor is prepared by a coprecipitation method, and the coprecipitation method comprises the following steps:
dissolving metal salt containing nickel, cobalt and manganese in a first solvent to prepare a metal mixed solution;
and mixing the metal mixed solution and the precipitant solution, carrying out coprecipitation reaction, and aging, separating and drying to obtain the nickel-cobalt-manganese precursor.
6. The preparation method of claim 5, wherein in the coprecipitation reaction, the pH value is adjusted to 7.5-11.5, and the coprecipitation reaction is carried out at 40-75 ℃ in a protective atmosphere, and the reaction time is 6-36 h.
7. The method according to any one of claims 1 to 6, wherein the molar ratio of the nickel-cobalt-manganese precursor to the niobium-containing compound is 100: (0.1-5); and/or the molar sum of nickel, cobalt and manganese metals in the precursor is as follows: the ratio of the molar sum of the first portion of lithium salt to the second portion of lithium salt is 1: (1.2-1.7).
8. The preparation method according to claim 5, wherein the molar concentration of the total metal of nickel, cobalt and manganese in the metal mixed solution is 0.5-3 mol/L, and/or the molar concentration of the precipitant in the precipitant solution is 0.5-4 mol/L.
9. A positive electrode material, which is characterized by comprising the niobium-modified lithium-rich manganese-based material obtained by the preparation method of the niobium-modified lithium-rich manganese-based material according to any one of claims 1 to 8.
10. A lithium ion battery comprising a positive electrode, a negative electrode, and a separator, wherein the positive electrode comprises the positive electrode material according to claim 9.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113683122A (en) * | 2021-08-19 | 2021-11-23 | 蜂巢能源科技有限公司 | Iron-manganese-based positive electrode material, and preparation method and application thereof |
| CN114566625A (en) * | 2022-03-02 | 2022-05-31 | 重庆理英新能源科技有限公司 | Lithium-rich manganese-based positive electrode material with low pressure drop performance and preparation method and application thereof |
| CN114702082A (en) * | 2021-12-06 | 2022-07-05 | 宜宾锂宝新材料有限公司 | High-capacity low-pressure-drop lithium-rich manganese-based positive electrode material and preparation method thereof |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101117234A (en) * | 2006-08-04 | 2008-02-06 | 比亚迪股份有限公司 | Method for preparing doping lithium-enriching spinelle lithium manganese oxide |
| CN102306765A (en) * | 2011-08-18 | 2012-01-04 | 合肥国轩高科动力能源有限公司 | Preparation method for nickel-manganese-cobalt anode material of lithium ion battery |
| CN103441252A (en) * | 2013-08-12 | 2013-12-11 | 天津巴莫科技股份有限公司 | Method for preparing lithium-enriched manganese-based anode material of nano-oxide-coated lithium ion battery |
| US20160293952A1 (en) * | 2013-11-22 | 2016-10-06 | Sumitomo Metal Mining Co., Ltd. | Positive electrode active material for nonaqueous electrolyte secondary batteries and production method thereof, and nonaqueous electrolyte secondary battery |
| CN106654210A (en) * | 2016-12-22 | 2017-05-10 | 广州朝锂新能源科技有限公司 | High-temperature and long-cycle high-nickel positive electrode material for lithium-ion battery and preparation method of high-temperature and long-cycle high-nickel positive electrode material |
| CN106684323A (en) * | 2016-12-22 | 2017-05-17 | 广州朝锂新能源科技有限公司 | Ternary lithium-ion battery cathode material improved by active oxide multiply and preparation method thereof |
| CN107565122A (en) * | 2017-08-07 | 2018-01-09 | 复旦大学 | A kind of preparation method of doping type nickel-cobalt lithium manganate cathode material |
| CN110422890A (en) * | 2019-06-25 | 2019-11-08 | 当升科技(常州)新材料有限公司 | Anode material for lithium-ion batteries and preparation method thereof and lithium ion cell positive and lithium ion battery |
| CN110808371A (en) * | 2019-11-12 | 2020-02-18 | 中国科学院过程工程研究所 | Multi-element lithium-rich manganese-based positive electrode material and preparation method and application thereof |
| JP2020053383A (en) * | 2018-09-21 | 2020-04-02 | 住友金属鉱山株式会社 | Positive electrode active material for lithium ion secondary battery and method for producing the same, positive electrode mixture paste for lithium ion secondary battery, and lithium ion secondary battery |
-
2021
- 2021-04-29 CN CN202110473688.5A patent/CN113184923A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101117234A (en) * | 2006-08-04 | 2008-02-06 | 比亚迪股份有限公司 | Method for preparing doping lithium-enriching spinelle lithium manganese oxide |
| CN102306765A (en) * | 2011-08-18 | 2012-01-04 | 合肥国轩高科动力能源有限公司 | Preparation method for nickel-manganese-cobalt anode material of lithium ion battery |
| CN103441252A (en) * | 2013-08-12 | 2013-12-11 | 天津巴莫科技股份有限公司 | Method for preparing lithium-enriched manganese-based anode material of nano-oxide-coated lithium ion battery |
| US20160293952A1 (en) * | 2013-11-22 | 2016-10-06 | Sumitomo Metal Mining Co., Ltd. | Positive electrode active material for nonaqueous electrolyte secondary batteries and production method thereof, and nonaqueous electrolyte secondary battery |
| CN106654210A (en) * | 2016-12-22 | 2017-05-10 | 广州朝锂新能源科技有限公司 | High-temperature and long-cycle high-nickel positive electrode material for lithium-ion battery and preparation method of high-temperature and long-cycle high-nickel positive electrode material |
| CN106684323A (en) * | 2016-12-22 | 2017-05-17 | 广州朝锂新能源科技有限公司 | Ternary lithium-ion battery cathode material improved by active oxide multiply and preparation method thereof |
| CN107565122A (en) * | 2017-08-07 | 2018-01-09 | 复旦大学 | A kind of preparation method of doping type nickel-cobalt lithium manganate cathode material |
| JP2020053383A (en) * | 2018-09-21 | 2020-04-02 | 住友金属鉱山株式会社 | Positive electrode active material for lithium ion secondary battery and method for producing the same, positive electrode mixture paste for lithium ion secondary battery, and lithium ion secondary battery |
| CN110422890A (en) * | 2019-06-25 | 2019-11-08 | 当升科技(常州)新材料有限公司 | Anode material for lithium-ion batteries and preparation method thereof and lithium ion cell positive and lithium ion battery |
| CN110808371A (en) * | 2019-11-12 | 2020-02-18 | 中国科学院过程工程研究所 | Multi-element lithium-rich manganese-based positive electrode material and preparation method and application thereof |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113683122A (en) * | 2021-08-19 | 2021-11-23 | 蜂巢能源科技有限公司 | Iron-manganese-based positive electrode material, and preparation method and application thereof |
| CN113683122B (en) * | 2021-08-19 | 2022-12-09 | 蜂巢能源科技有限公司 | Iron-manganese-based positive electrode material, and preparation method and application thereof |
| CN114702082A (en) * | 2021-12-06 | 2022-07-05 | 宜宾锂宝新材料有限公司 | High-capacity low-pressure-drop lithium-rich manganese-based positive electrode material and preparation method thereof |
| CN114566625A (en) * | 2022-03-02 | 2022-05-31 | 重庆理英新能源科技有限公司 | Lithium-rich manganese-based positive electrode material with low pressure drop performance and preparation method and application thereof |
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