阅读说明：本技术 一种锂电池微纳米正极材料的制备方法 (Preparation method of micro-nano positive electrode material of lithium battery ) 是由 于志远 佘建峰 刘于航 于 2018-08-31 设计创作，主要内容包括：本发明为一种锂电池微纳米正极材料的制备方法。一种锂电池微纳米正极材料的制备方法,包括：(1)制备混合盐溶液；(2)制备碱溶液；(3)在10-80℃下,将混合盐溶液和碱溶液注入微通道反应器进行反应,再通过陈化管式反应器流入陈化罐常压搅拌陈化2-10h,得共沉淀反应混合物；(4)将沉淀反应混合物固液分离后,洗涤,干燥,得前驱体；(5)根据前驱体中锂盐的含量,对前驱体进行处理,再高温固化反应,得所述的锂电池微纳米正极材料。本发明所述的一种锂电池微纳米正极材料的制备方法,该制备方法基于微通道反应器,可连续制备锂电池正极材料前驱体微纳米粒子,条件温和、采用水相体系、工艺简单、锂电池正极材料前驱体形貌可控、过程连续。(The invention relates to a preparation method of a micro-nano positive electrode material of a lithium battery. A preparation method of a lithium battery micro-nano positive electrode material comprises the following steps: (1) preparing a mixed salt solution; (2) preparing an alkali solution; (3) injecting the mixed salt solution and the alkali solution into a microchannel reactor for reaction at the temperature of 10-80 ℃, then flowing into an aging tank through an aging tubular reactor, stirring and aging for 2-10h at normal pressure, and obtaining a coprecipitation reaction mixture; (4) carrying out solid-liquid separation on the precipitation reaction mixture, washing and drying to obtain a precursor; (5) and treating the precursor according to the content of lithium salt in the precursor, and then carrying out high-temperature curing reaction to obtain the micro-nano positive electrode material of the lithium battery. According to the preparation method of the lithium battery micro-nano anode material, disclosed by the invention, micro-nano particles of the lithium battery anode material precursor can be continuously prepared on the basis of the microchannel reactor, the condition is mild, a water phase system is adopted, the process is simple, the shape of the lithium battery anode material precursor is controllable, and the process is continuous.)

1. A preparation method of a lithium battery micro-nano positive electrode material is characterized in that the lithium battery micro-nano positive electrode material comprises a ternary positive electrode material and a lithium-rich manganese-based positive electrode material, and the preparation method comprises the following steps:

(1) preparing a mixed salt solution:

completely dissolving metal salt in water to prepare a salt solution with the metal ion concentration of 0.25-2mol/L to obtain a mixed salt solution; the metal salt is nickel salt, cobalt salt and aluminum salt, or nickel salt, cobalt salt, aluminum salt and lithium salt, or nickel salt, cobalt salt and manganese salt, or nickel salt, cobalt salt, manganese salt and lithium salt;

when the micro-nano positive electrode material of the lithium battery is a ternary positive electrode material, the molar ratio of metal ions in the nickel salt, the cobalt salt, the aluminum salt or the manganese salt is Ni: co: al or Mn ═ 1 to 9: 0.05-1.5: 0.05 to 1; the molar ratio of the lithium salt to the metal ions in the metal salts other than the lithium salt is Li: ni + Co + Al or Mn 1-1.2: 1;

when the lithium battery micro-nano positive electrode material is a lithium-rich manganese-based positive electrode material, the molar ratio of metal ions in the metal salt is Li: mn + Ni + Co ═ 3:2, Mn: ni + Co ═ 5-9: 1-5;

(2) preparing an alkali solution:

completely dissolving soluble alkali in water to prepare a solution with the solubility of the soluble alkali being 1-5mol/L, thus obtaining an alkali solution; the soluble alkali is one of ammonium bicarbonate, sodium hydroxide, 8-hydroxyquinoline, sodium carbonate, ammonia water and potassium hydroxide;

(3) injecting the mixed salt solution and the alkali solution into a microchannel reactor for reaction at the temperature of 10-80 ℃, then flowing into an aging tank through an aging tubular reactor, stirring and aging for 2-10h at normal pressure, and obtaining a coprecipitation reaction mixture;

(4) after solid-liquid separation is carried out on the precipitation reaction mixture, washing the solid matter for 3-4 times, and drying to obtain a precursor;

(5) the lithium battery micro-nano positive electrode material is a ternary positive electrode material, and when the mixed salt solution contains lithium salt, the precursor is subjected to high-temperature curing reaction to obtain the ternary positive electrode material, namely the lithium battery micro-nano positive electrode material;

when no lithium salt is included in the mixed salt solution: uniformly mixing the precursor with lithium salt, wherein the molar ratio of the precursor to metal elements in the lithium salt is 1:1-1.2, and carrying out high-temperature curing reaction to obtain a ternary cathode material, namely the micro-nano cathode material of the lithium battery;

when the lithium battery micro-nano positive electrode material is a lithium-rich manganese-based positive electrode material, uniformly mixing a precursor with a lithium salt, wherein the molar ratio of metal elements in the precursor except lithium elements to metal elements in the lithium salt is 1:1-1.2, and carrying out high-temperature curing reaction to obtain the lithium-rich manganese-based positive electrode material, namely the lithium battery micro-nano positive electrode material.

2. The method according to claim 1, wherein,

in the step (1), the metal salt is sulfate, nitrate, acetate or hydrochloride;

in the step (2), the soluble alkali is ammonium bicarbonate;

in the step (5), the lithium salt is at least one of lithium hydroxide, lithium acetate, lithium oxalate and lithium carbonate.

3. The method according to claim 2, wherein,

the metal salt is a sulfate.

4. The method according to claim 1, wherein,

the molar ratio of metal ions in the nickel salt, the cobalt salt and the manganese salt is 8:1: 1;

the molar ratio of metal ions in the nickel salt, the cobalt salt and the aluminum salt is 8:1.5: 0.5.

5. The method according to claim 1, wherein,

in the step (3), the substrate of the microchannel reactor is sapphire, ceramic, alloy or glass;

the microchannel reactor comprises a liquid inlet channel I, a liquid inlet channel II and a reaction channel, wherein the outlet end of the reaction channel is communicated with the aging tubular reactor.

6. The method according to claim 5, wherein,

the substrate of the microchannel reactor is sapphire;

the diameters of the liquid inlet channel I and the liquid inlet channel II are 0.01-1 mm;

the inner diameter of the reaction channel is 0.01-1.5mm, and the length is 10-200 mm;

the length of the aging tubular reactor is 50-5000 mm.

7. The method according to claim 1, wherein,

the microchannel reactor is a T-shaped microchannel reactor and comprises two seal plates and 1-100 microchannel plates, and 2-1000 microchannels are arranged on the microchannel plates.

8. The method according to claim 7, wherein,

the microchannel reactor comprises 5-20 microchannel plates, and 20-100 microchannels are arranged on the microchannel plates.

9. The method according to claim 1, wherein,

in the step (4), the drying is as follows: vacuum drying at 80-200 deg.C for 12-24 hr.

10. The method according to claim 1, wherein,

in the step (5), the high-temperature curing reaction is as follows: calcining at the temperature of 700-900 ℃ for 2-40 hours after presintering at the temperature of 300-600 ℃ for 2-20 hours.

Technical Field

The invention belongs to the technical field of material chemistry, and particularly relates to a preparation method of a micro-nano positive electrode material of a lithium battery.

Background

The nickelization of ternary materials is an inevitable direction for the development of new energy batteries in the future. The power batteries in China still mainly produce batteries of NCM111 and NCM523 at present, and the current trend is gradually changed to NCM622, 811 or NCA. The development trend is that in the ternary material, Ni and Co are main active materials, and the increasing proportion of Ni can increase the specific capacity of the material and meet the requirement of increasing the energy density of the battery.

The ternary material patent is held in the japanese korean hands. According to the information of the china industry information network, the basic patent of ternary NCM is held by 3M company in the united states, and 3M company does not relate to the production of ternary materials, but obtains profits by means of the transfer of granted patents, wherein LG, SK, and eumech were granted to the 3M purchase of ternary materials. The main patent of NCA is held in japan panasonic and sumitomo, and the patent limit is globally valid. At present, related patents of ternary materials are mainly focused on Japanese and Korean hands, the top three patents are Toyota, Sony and Toshiba respectively, and the technical barriers of the patents prevent the manufacturers of the ternary materials in China from being difficult to enter international large factories, and the patents become common means for avoiding patent litigation by positive material enterprises in China through means of modification addition, production process improvement and the like.

Integrated LiCoO₂，LiNiO₂，LiMnO₂The three lithium ion battery anode materials have the advantages that the performance of the ternary material is better than that of any single-component anode material, and the ternary material has obvious synergistic effect and is considered as a novel anode material with the most application prospect. At present, the research on the nickel-cobalt-manganese ternary cathode material mainly focuses on the synthesis of the material and the relationship between the electrochemical performance and the structure.

In practical batteries, physical characteristics such as morphology, particle size distribution, specific surface area and tap density of positive electrode material particles greatly affect the processing performance of materials and the comprehensive electrical performance of batteries, and in order to widen the application range of lithium ion batteries, especially to apply ternary materials to power batteries with strict requirements on safety, cyclicity and rate characteristics, the preparation of spherical ternary materials with high density and uniform particle size distribution has become a hotspot of research, and how to improve the tap density of the ternary materials on the premise of ensuring the electrochemical performance is the key of the large-scale application of the ternary materials.

The main preparation methods of ternary materials are roughly divided into solid phase methods and solution methods. The solid phase method includes a high temperature solid phase method and an acetate combustion method. The solution method mainly comprises a sol-gel method, a coprecipitation method, a spray pyrolysis method and the like. Different synthetic methods have great influence on the performance of the prepared ternary material.

The traditional solid phase synthesis technology is difficult to enable the materials to reach the stoichiometric ratio of molecular or atomic linear degree, and the coprecipitation method can solve the problem, so that the aim of preparing high-quality materials at lower production cost is fulfilled.

The coprecipitation method is generally to mix the chemical raw materials in a solution state and add a proper precipitator into the solution to coprecipitate the components which are mixed uniformly in the solution according to a stoichiometric ratio, or to precipitate an intermediate product by reaction in the solution and then calcine and decompose the intermediate product to prepare a product of fine powder. The coprecipitation method has the following four characteristics: (1) the process equipment is simple, synthesis and refinement can be completed at the same time during the precipitation period, and the method is favorable for industrial production; (2) the contents of all components can be accurately controlled relatively, so that the different components can be uniformly mixed at a molecular/atomic level; (3) in the precipitation process, the purity, the particle size, the dispersity and the phase composition of the obtained powder can be controlled by controlling the precipitation conditions and the calcination degree of the precipitate in the next step; (4) compared with a high-temperature solid phase method, the method has the advantages of lower sample calcination temperature, stable performance and good reproducibility.

The hydrothermal synthesis technique refers to a method of chemical synthesis in a supersaturated aqueous solution at high temperature and high pressure. It belongs to one kind of wet chemical synthesis. The powder synthesized by the hydrothermal method generally has high crystallinity, does not contain any crystal water by optimizing the synthesis conditions, and can strictly control the size, uniformity, shape and components of the powder. The hydrothermal synthesis omits a calcination step and thus a grinding step, so that the purity of the powder is high and the density of crystal defects is reduced.

Therefore, at present, the research and production of the lithium battery cathode material are mostly carried out in a batch type and coprecipitation reaction operation in a traditional reaction kettle. However, these operations are difficult to control the reaction precisely, which makes the process cumbersome, the reaction discontinuous, and the production efficiency low. In order to overcome the defects of intermittent production, complex process, uneven particle size and uneven morphology of products in batches in the traditional method, a method which can not only realize continuous mass production but also keep obtaining micro-nano particles with uniform particle size and morphology needs to be found.

In view of this, the invention provides a preparation method of a micro-nano positive electrode material of a lithium battery.

Disclosure of Invention

The invention aims to provide a preparation method of a lithium battery micro-nano anode material, which is based on a microchannel reactor, can continuously prepare micro-nano particles of a lithium battery anode material precursor, is mild in condition, adopts a water phase system, is simple in process, is controllable in shape of the lithium battery anode material precursor, is continuous in process, and is suitable for large-scale production.

In order to realize the purpose, the adopted technical scheme is as follows:

a preparation method of a micro-nano positive electrode material of a lithium battery comprises a ternary positive electrode material and a lithium-rich manganese-based positive electrode material, and comprises the following steps:

(1) preparing a mixed salt solution:

completely dissolving metal salt in water to prepare a salt solution with the metal ion concentration of 0.25-2mol/L to obtain a mixed salt solution; the metal salt is nickel salt, cobalt salt and aluminum salt, or nickel salt, cobalt salt, aluminum salt and lithium salt, or nickel salt, cobalt salt and manganese salt, or nickel salt, cobalt salt, manganese salt and lithium salt;

when the micro-nano positive electrode material of the lithium battery is a ternary positive electrode material, the molar ratio of metal ions in the nickel salt, the cobalt salt, the aluminum salt or the manganese salt is Ni: co: al or Mn ═ 1 to 9: 0.05-1.5: 0.05 to 1; the molar ratio of the lithium salt to the metal ions in the metal salts other than the lithium salt is Li: ni + Co + Al or Mn 1-1.2: 1;

when the lithium battery micro-nano positive electrode material is a lithium-rich manganese-based positive electrode material, the molar ratio of metal ions in the metal salt is Li: mn + Ni + Co ═ 3:2, Mn: ni + Co ═ 5-9: 1-5;

(2) preparing an alkali solution:

completely dissolving soluble alkali in water to prepare a solution with the solubility of the soluble alkali being 1-5mol/L, thus obtaining an alkali solution; the soluble alkali is one of ammonium bicarbonate, sodium hydroxide, 8-hydroxyquinoline, sodium carbonate, ammonia water and potassium hydroxide;

(3) injecting the mixed salt solution and the alkali solution into a microchannel reactor for reaction at the temperature of 10-80 ℃, then flowing into an aging tank through an aging tubular reactor, stirring and aging for 2-10h at normal pressure, and obtaining a coprecipitation reaction mixture;

(4) after solid-liquid separation is carried out on the precipitation reaction mixture, washing the solid matter for 3-4 times, and drying to obtain a precursor;

(5) the lithium battery micro-nano positive electrode material is a ternary positive electrode material, and when the mixed salt solution contains lithium salt, the precursor is subjected to high-temperature curing reaction to obtain the ternary positive electrode material, namely the lithium battery micro-nano positive electrode material;

when no lithium salt is included in the mixed salt solution: uniformly mixing the precursor with lithium salt, wherein the molar ratio of the precursor to metal elements in the lithium salt is 1:1-1.2, and carrying out high-temperature curing reaction to obtain a ternary cathode material, namely the micro-nano cathode material of the lithium battery;

when the lithium battery micro-nano positive electrode material is a lithium-rich manganese-based positive electrode material, uniformly mixing a precursor with a lithium salt, wherein the molar ratio of metal elements in the precursor except lithium elements to metal elements in the lithium salt is 1:1-1.2, and carrying out high-temperature curing reaction to obtain the lithium-rich manganese-based positive electrode material, namely the lithium battery micro-nano positive electrode material.

Further, in the step (1), the metal salt is a sulfate, a nitrate, an acetate, or a hydrochloride;

in the step (2), the soluble alkali is ammonium bicarbonate;

in the step (5), the lithium salt is at least one of lithium hydroxide, lithium acetate, lithium oxalate and lithium carbonate.

Still further, the metal salt is a sulfate.

Further, the molar ratio of metal ions in the nickel salt, the cobalt salt and the manganese salt is 8:1: 1;

the molar ratio of metal ions in the nickel salt, the cobalt salt and the aluminum salt is 8:1.5: 0.5.

Further, in the step (3), the substrate of the microchannel reactor is sapphire, ceramic, alloy or glass;

the microchannel reactor comprises a liquid inlet channel I, a liquid inlet channel II and a reaction channel, wherein the outlet end of the reaction channel is communicated with the aging tubular reactor.

Still further, the substrate of the microchannel reactor is sapphire;

the diameters of the liquid inlet channel I and the liquid inlet channel II are 0.01-1 mm;

the inner diameter of the reaction channel is 0.01-1.5mm, and the length is 10-200 mm;

the length of the aging tubular reactor is 50-5000 mm.

Furthermore, the microchannel reactor is a T-shaped microchannel reactor and comprises two close plates and 1-100 microchannel plates, and 2-1000 microchannels are arranged on the microchannel plates.

Still further, the microchannel reactor comprises 5-20 microchannel plates, and 20-100 microchannels are arranged on the microchannel plates.

Further, in the step (4), the drying is: vacuum drying at 80-200 deg.C for 12-24 hr.

Further, in the step (5), the high-temperature curing reaction is: calcining at the temperature of 700-900 ℃ for 2-40 hours after presintering at the temperature of 300-600 ℃ for 2-20 hours.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the preparation method of the lithium battery micro-nano cathode material, the pre-synthesis of seed crystals is not needed, the reaction conditions are mild, a water phase system is adopted, the process is simple, the process is continuous, the high-capacity, high-rate and high-consistency cathode material precursor is prepared, the particle size and morphology consistency of the cathode material precursor are good, the material is mixed according to the molecular or atomic linear stoichiometric ratio, no agglomeration exists, the particle yield is high, the consistency of batch products is good, and the result is repeated and stable.

2. According to the preparation method of the lithium battery micro-nano anode material, micro-particles and nano-particles with different particle sizes can be produced by changing parameters such as flow, injection pressure, inner diameter and length of a micro-channel reaction channel and the like of liquid flowing into each inlet of a micro-channel reactor.

3. According to the preparation method of the lithium battery micro-nano positive electrode material, the prepared positive electrode material precursor can be classified into micro-particles and nano-particles, the micro-particle size range is 0.1-500 um, and the nano-particle size range is 10-1000 nm.

Drawings

FIG. 1 is a process flow diagram of the present invention for preparing a ternary cathode material and a lithium-rich manganese-based cathode material without adding a lithium salt in the preparation of a mixed salt solution;

FIG. 2 is a process flow diagram of the present invention for preparing a ternary cathode material by adding a lithium salt during the preparation of a mixed salt solution;

FIG. 3 is a microchannel reactor, an aging tube reactor, and an aging tank.

Detailed Description

In order to further illustrate the preparation method of the micro-nano positive electrode material for the lithium battery of the present invention, and achieve the intended purpose of the invention, the following detailed description is provided with reference to the preferred embodiments for the preparation method of the micro-nano positive electrode material for the lithium battery according to the present invention, and the specific implementation, structure, characteristics, and efficacy thereof. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Before explaining the preparation method of the micro-nano cathode material of the lithium battery in detail, the method and the like mentioned in the invention need to be further explained to achieve better effects.

The microchannel reactor is taken as a leading-edge technology which is started in the 90 s of the 21 st century, not only can strengthen mass transfer and heat transfer, but also can be continuously and industrially produced in a large scale, and is widely concerned by people. Because the reaction mode of the microchannel reactor is the collision of reaction fluids, and is not the simple dropwise addition of the traditional reactor, the microchannel reactor has unique advantages in material synthesis: the reaction fluid can be quickly mixed, the mixing time is shorter than the reaction time, a stable and uniform reaction environment is formed, back mixing is avoided, the particle size distribution of the obtained micro-nano particles is narrow, the materials are mixed according to the stoichiometric ratio of molecular or atomic linear degree, and products can be removed in time, so that agglomeration is reduced.

In the preparation of the mixed salt solution, the metal salt is soluble metal salt, and the manganese salt can be one or the mixed salt of manganese sulfate, manganese nitrate, manganese chloride and manganese acetate; the nickel salt can be one or a mixture of nickel sulfate, nickel nitrate, nickel chloride and nickel acetate; the cobalt salt is one or a mixture of cobalt sulfate, cobalt nitrate and cobalt chloride.

When the lithium battery micro-nano positive electrode material is a ternary positive electrode material, the lithium salt is added in two modes, namely ① lithium salt is added during preparation of a salt solution, a precursor is directly subjected to high-temperature curing reaction after preparation, and ② lithium salt is added after the precursor is prepared.

When the lithium battery micro-nano positive electrode material is a lithium-rich manganese-based positive electrode material, lithium salt is added when a salt solution is prepared, wherein the ratio of Li: the molar ratio of Mn + Ni + Co is 3:2, and Mn element accounts for 50-90% of (Mn + Ni + Co) element; after the precursor is prepared, lithium salt is added for high-temperature curing reaction.

FIG. 3 is a microchannel reactor, aging tube reactor, and aging tank of the present application. In the figure, A is a liquid inlet channel I, B is a liquid inlet channel II, C is a reaction channel, D is an aging tubular reactor, E is an aging tank, and F is a microchannel reactor unit.

With the above methods and the like understood, the method for preparing the lithium battery micro-nano positive electrode material of the present invention will be further described in detail with reference to the specific embodiments and fig. 1 and 3: