阅读说明：本技术 一种大单晶锂离子电池镍钴锰酸锂正极材料制备方法 (A kind of large single crystal lithium ion battery nickle cobalt lithium manganate method for preparing anode material ) 是由 方明 毛秦钟 胡子俊 施翼杰 戚思炀 张中彩 吉同棕 王寅峰 钱志挺 吴海军 于 2019-07-21 设计创作，主要内容包括：本发明涉及一种单晶型锂离子电池镍钴锰酸锂正极材料的制备方法,其包括以下步骤：(1)以小粒晶球状的NCM三元前驱体、锂盐、含A元素的纳米助熔剂为原料,采用干法高速混料的方式混合均匀,在富氧的气氛条件下,进行一次烧结；(2)将烧结后的材料进行鄂破、对辊、粉碎、过筛,得到单晶一烧基材；(3)将一烧基材与含B元素的纳米包覆剂进行混合,在富氧的气氛条件下,再次进行烧结,然后将其进行颚破、对辊、粉碎、过筛,得到大单晶镍钴锰酸锂正极材料。本发明专利制备的正极材料,具有颗粒尺寸大、分散性好、比表面积适中、压实密度高、高电压、高温循环性能好等特点。(The present invention relates to a kind of preparation methods of monocrystalline type lithium ion battery nickle cobalt lithium manganate positive electrode, itself the following steps are included: (1) using the NCM ternary precursor of granule geode shape, lithium salts, the nanometer fusing assistants containing element A as raw material, it is uniformly mixed by the way of dry method high speed mixing, under oxygen-enriched atmospheric condition, carry out once sintered；(2) sintered material is carried out Hubei Province to break, to roller, crushing, sieving, obtains monocrystalline one and burns substrate；(3) a burning substrate is mixed with the nanometer covering containing B element, under oxygen-enriched atmospheric condition, is sintered again, is then carried out jaw and broken, to roller, crushing, sieving, obtain large single crystal nickel-cobalt lithium manganate cathode material.The positive electrode of the invention patent preparation has the characteristics that particle size is big, good dispersion, specific surface area is moderate, compacted density is high, high voltage, high temperature cyclic performance are good.)

1. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode, which is characterized in that including following step It is rapid:

(1) using the NCM ternary precursor of granule geode shape, lithium salts, the nanometer fusing assistants containing element A as raw material, using dry method height The mode of fast mixing is uniformly mixed, and under oxygen-enriched atmospheric condition, is carried out once sintered；

(2) sintered material is carried out Hubei Province to break, to roller, crushing, sieving, obtains monocrystalline one and burns substrate；

(3) a burning substrate is mixed with the nanometer covering containing B element, under oxygen-enriched atmospheric condition, is burnt again Then knot is carried out jaw and is broken, to roller, crushing, sieving, obtains large single crystal nickel-cobalt lithium manganate cathode material.

2. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, in step (1), the NCM ternary precursor of the raw material granule geode shape used, average grain crystalline substance D50 is 3.5~ 4.5 μm, specific surface area BET is less than 5m²/ g, apparent density > 1.2g/cm3, tap density > 2.0g/cm3, sphere cross-section morphology are in Radial distribution, without obvious layering, hole or crackle, crystallinity is high, and main peak is obvious, FWHM (001) < 0.45 or I (001)/I (101) it is greater than 1.5.

3. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, lithium salts is lithium carbonate or lithium hydroxide, and Li/Me (Ni+Co+Mn) molar ratio is 1.02 in ingredient in step (1) ~1.2；Cosolvent containing element A is fluoride, and element A is metallic element, and optional fluoride is NaF, KF, AlF3, ZrF₄、 BaF₂、MgF₂、CaF₂、TiF₄、VF₄、SrF₂、YF₃, wherein the total metal of metal element A accounting presoma is first in fluoride additive Plain 0.1~1.0wt% of weight.

4. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, in step (1), one of the optional high speed ball mill of mixing equipment, high-speed mixer, coulter type mixer, 2~8h of mixing time, 30~150Hz of mixing frequency.

5. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, in step (1), sintering reaction condition is the volumetric concentration 50~99% of oxygen atmosphere, sintering temperature 700~ 1000 DEG C, 2~10 DEG C/min of heating rate, 6~30h of target temperature soaking time.

6. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, jaw is broken in step (2), is to roller, pulverization conditions

Admission pressure: 0.2~5MPa,

Jaw is broken, to roller crack spacing: 0.1~0.5mm,

Air-flow crushing frequency: 20~50Hz,

Grade frequency: 20~200Hz；

Smashed ternary material:

Average grain diameter D50:2.0~6.0 μm,

PH:11.60~12.20,

Specific surface area BET:0 < y < 1m²/g；

Residual alkali: CO₃ ^2-<2500ppmw、OH^-<2500ppmw。

7. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, the covering containing B element in step (3), selectable compound have: metallorganic and metaphosphate；Packet It is optional to cover agent element B: B, Al, Ba, Zr, Mg, Ca, Ti, Si, V, Sc, Nb, Ta, Y；Wherein element B accounts for an imitation frosted glass weight in covering Amount: 0.1~1wt%.

8. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, sintering reaction condition in step (3) are as follows: the volumetric concentration 21.7~99.9% of oxygen atmosphere, sintering temperature 300 ~800 DEG C, 3~10 DEG C/min of heating rate, soaking time 6~for 24 hours.

9. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, jaw breaks, is 0.2~5MPa of admission pressure to roller, pulverization conditions in step (3), jaw is broken, to roller crack spacing 0.1~0.5mm, air-flow crushing 20~50Hz of frequency, 20~200Hz of grade frequency.

10. a kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode according to claim 1, It is characterized in that, the chemical formula of the monocrystalline positive electrode of acquisition is LiNixCoyMnzO in the step (3)₂, wherein x+y+z =1,0.6≤x < 1,0 < y < 0.2,0 < z < 0.2；Average grain diameter D50:5.0~7.0 μm；PH 11.40~11.80；Specific surface area BET:0 < y < 0.5m²/g；Residual alkali: CO₃ ^2-< 1200ppmw, OH^-<1200ppmw。

Technical field

The present invention relates to new-energy automobile lithium ion power battery technology fields, and in particular to a kind of large single crystal lithium ion The preparation method of battery nickel-cobalt lithium manganate cathode material.

Background technique

Since 2013, domestic new-energy automobile subsidy maintains entire lowering trend；2018, continual mileage 150km Vehicle below stops paying out financial subsidies, and the subsidy of high continual mileage vehicle then upwards, this is the one big of subsidy new policies in 2018 Feature；However, 2019, continual mileage 250km vehicle below stops paying out financial subsidies, and high continual mileage vehicle subsidizes amount, Transfer dramatic decrease on the basis of 2018.

2019, subsidy was substantially fallen off, and causing market to new-energy automobile power battery, more stringent requirements are proposed, such as: High security, high-energy density, long circulating performance, thermal stability are good, at low cost.The specific capacity and energy of tertiary cathode material are close Degree is apparently higher than the positive product such as LiFePO4, LiMn2O4, cobalt acid lithium, meets and improves energy density developing direction.

The promotion of lithium-ion-power cell energy density reaches except through improving the content of the Ni in NCM ternary material Other than the purpose for promoting specific capacity；It can also be realized by improving charge and discharge blanking voltage and material compacted density.Monocrystalline three First NCM positive electrode has the double grading of high voltage and high-pressure solid；And then monocrystalline tertiary cathode material is promoted gradually to substitute often Secondary ball material is advised, main direction of studying is become.

Monocrystalline type material compares second particle spheroidal material, has many advantages, such as high voltage and long circulating；It is primarily due to list Brilliant material is in cell fabrication processes, unlike second particle spheroidal material causes material crack or micro- occur because of roll-in pole piece Crackle；And then in electrochemistry cyclic process, it is easy to cause part positive active material cracked or even stripping group body surface There is pole piece powder phenomenon-tion in face.The primary particle size of monocrystalline type material is larger, anti-pressure ability with higher；In addition, larger Crystal can be good at the stability for ensureing its structure in electrochemistry cyclic process, and then possess preferable room temperature and height Warm cycle performance.

But there is also following disadvantages for monocrystalline type tertiary cathode material, such as: (1) capacity is low under identical voltage, due to The sintering temperature of monocrystalline type material is higher by 20-30 DEG C than secondary ball material, and monocrystalline type primary particle average particle size is about 2- 3um；The primary particle average particle size of secondary ball-type is about 0.5-0.8um；Therefore, the first charge discharge efficiency of monocrystalline type material can be obvious Lower than secondary ball profile material, cause it relatively low in identical voltage discharge capacity.

(2) large specific surface area: currently, monocrystalline type positive electrode selects little particle presoma as raw material, average particle size is about For 3-5um；If selecting in the little particle presoma of continuity method preparation, the fine powder of certain weight proportion can be mingled with, cause specific surface area inclined Greatly, and then cause the monocrystalline positive electrode specific surface area of preparation bigger than normal, subsequent battery process is required higher.

(3) preparation process difficulty is high: little particle precursor preparation process, to crystal nucleation, growth, middle control control, sulfur reduction Except sodium requirement is higher；Secondly, monocrystalline positive electrode sintering temperature is high, energy consumption is high, and crushes post-processing, and the requirement to equipment is more It is high.

This patent for problem above existing for monocrystal material, develop a kind of low cost, it is simple, be applicable to scale The method of application；Batch process little particle presoma is selected, the method being sintered by Fluxing activity prepares monocrystalline tertiary cathode material Material, with particle size is big, good dispersion, specific surface area is moderate, compacted density is high, high voltage, high temperature cyclic performance are good.

Summary of the invention

The synthesis of monocrystalline type NCM ternary material selects little particle presoma as raw material (D50:3-5um), technique control Process difficulty processed is higher than the presoma (D50:10-12um) of regular particle size；In addition, the primary particle of little particle presoma Form, thickness, crystallinity, consistency, specific surface area etc., all can be to the form and internal structure of monocrystalline positive electrode primary particle Have an impact；And then it will affect the capacity and cycle performance of monocrystal material.

Based on the above prior art, the purpose of the present invention is to provide a kind of low cost, it is simple, be applicable to scale application Method；Suitable little particle presoma is selected, the method being sintered by Fluxing activity prepares monocrystalline tertiary cathode material,

In order to achieve the goal above, the technical solution adopted by the present invention are as follows:

A kind of preparation method of large single crystal lithium ion battery nickle cobalt lithium manganate positive electrode, comprising the following steps:

(1) using the NCM ternary precursor of granule geode shape, lithium salts, the nanometer fusing assistants containing element A as raw material, using dry The mode of method high speed mixing is uniformly mixed, and under oxygen-enriched atmospheric condition, is carried out once sintered；

(2) sintered material is carried out Hubei Province to break, to roller, crushing, sieving, obtains monocrystalline one and burns substrate；

(3) a burning substrate is mixed with the nanometer covering containing B element, under oxygen-enriched atmospheric condition, again into Then row sintering is carried out jaw and is broken, to roller, crushing, sieving, obtains large single crystal nickel-cobalt lithium manganate cathode material.

In order to preferably realize the present invention, further, in step (1), the NCM ternary of the raw material granule geode shape used Presoma, average grain crystalline substance D50 are 3.5~4.5 μm, and specific surface area BET is less than 5m²/ g, apparent density > 1.2g/cm3, vibration density Degree > 2.0g/cm3, sphere cross-section morphology are radially distributed, and without obvious layering, hole or crackle, crystallinity is high, and main peak is obvious, FWHM (001) < 0.45 or I (001)/I (101) is greater than 1.5.

In order to preferably realize the present invention, further, in step (1), lithium salts is lithium carbonate or lithium hydroxide, in ingredient Li/Me (Ni+Co+Mn) molar ratio is 1.02~1.2；Cosolvent containing element A is fluoride, and element A is metallic element, optional Fluoride be NaF, KF, AlF3, ZrF₄、BaF₂、MgF₂、CaF₂、TiF₄、VF₄、SrF₂、YF₃, wherein golden in fluoride additive Belong to 0.1~1.0wt% of the total metallic element weight of elements A accounting presoma.

In order to preferably realize the present invention, further, in step (1), the optional high speed ball mill of mixing equipment, high speed are mixed One of conjunction machine, coulter type mixer, 2~8h of mixing time, 30~150Hz of mixing frequency.

In order to preferably realize the present invention, further, in step (1), sintering reaction condition is the volume of oxygen atmosphere Concentration 50~99%, 700~1000 DEG C of sintering temperature, 2~10 DEG C/min of heating rate, 6~30h of target temperature soaking time.

In order to preferably realize the present invention, further, jaw is broken in step (2), is to roller, pulverization conditions

Admission pressure: 0.2~5MPa,

Jaw is broken, to roller crack spacing: 0.1~0.5mm,

Air-flow crushing frequency: 20~50Hz,

Grade frequency: 20~200Hz；

Smashed ternary material:

Average grain diameter D50:2.0~6.0 μm,

PH:11.60~12.20,

Specific surface area BET:0 < y < 1m²/g；

Residual alkali: CO₃ ^2-<2500ppmw、OH^-<2500ppmw。

In order to preferably realize the present invention, further, the covering containing B element in step (3), selectable compound Have: metallorganic and metaphosphate；Covering element B is optional: B, Al, Ba, Zr, Mg, Ca, Ti, Si, V, Sc, Nb, Ta, Y； Wherein element B accounts for an imitation frosted glass weight: 0.1~1wt% in covering.

In order to preferably realize the present invention, further, sintering reaction condition in step (3) are as follows: the volume of oxygen atmosphere Concentration 21.7~99.9%, 300~800 DEG C of sintering temperature, 3~10 DEG C/min of heating rate, soaking time 6~for 24 hours.

In order to preferably realize the present invention, further, in step (3) jaw is broken, to roller, pulverization conditions is admission pressure 0.2~5MPa, jaw are broken, to roller crack 0.1~0.5mm of spacing, air-flow crushing 20~50Hz of frequency, 20~200Hz of grade frequency.

The chemical formula for the monocrystalline positive electrode that the present invention obtains is LiNixCoyMnzO₂, wherein x+y+z=1,0.6≤x < 1,0 < y < 0.2,0 < z < 0.2；Average grain diameter D50:5.0~7.0 μm；PH 11.40~11.80；Specific surface area BET:0 < y < 0.5m²/g；Residual alkali: CO₃ ^2-< 1200ppmw, OH^-<1200ppmw。

The large single crystal positive electrode of above-mentioned acquisition is assembled into button cell respectively, concrete technology: positive electrode, acetylene Black, Kynoar PVDF is weighed according to the mass ratio of 95:2.5:2.5, is uniformly mixed, NMP stirring 4h is added, and slurry is made Material, is then coated uniformly on aluminium foil, then 80 DEG C of vacuum bakeouts, tabletting, the positive plate for being cut into diameter 14mm；In addition, matching Using the lithium piece of diameter 16mm as cathode, syringe is added dropwise 5 drop 1mol/L LiPFO4+DEC/EC (volume ratio 1) mixed solutions and is Electrolyte, microporous polypropylene membrane are diaphragm, and the assembling of button cell is carried out in the glove box full of argon gas.

By the button cell after assembling, 3.0-4.3V of volume test, 0.1C/0.1C and loop test 3.0-are carried out 4.3V, 1C/1C.

Beneficial effect

Beneficial effects of the present invention are as follows:

1, synthesize low specific surface area, fine and close little particle presoma: the presoma primary particle is clear, lamella is accumulated, thick Degree is uniform, few surface defects, and the positive electrode defect being sintered out as template is also corresponding less；Meanwhile primary particle is accumulated Closely, thickness reaches 300nm, and specific surface area BET is small, and being more suitable for sintering fusion is large single crystal；In addition, in XRD material phase analysis, it is special It levies peak half-peak breadth FWHM (001) < 0.45, main peak I (001)/I (101) is greater than 1.5, shows that the crystallinity of presoma is high, is suitable for The preparation of positive monocrystal material.

2, fluoride is doped: traditional oxide is doped, and higher sintering temperature is needed just to be able to achieve effectively Doping；Because oxide structure is more stable, Me-O bond energy is larger, and activity is poor, is not easy to realize uniformly mixing for basis material It is miscellaneous.It is doped using suitable fluoride system, sintering driving force can be reduced, suitably reduction sintering temperature, realized fluxing Effect, reach and improve single crystal grain size, and do not reduce the purpose of material capacity.

3, large size single crystal structure positive electrode: high compacted density may be implemented in large size single crystal, has preferable resistance to compression Performance, and in electrochemistry cyclic process, it is able to maintain preferable structural stability, and then improve the cycle performance of material.

Detailed description of the invention

Fig. 1 is the preparation technology flow chart of large single crystal nickel-cobalt lithium manganate cathode material；

Fig. 2 is the presoma shape appearance figure that the embodiment of the present invention 1 is prepared；

Fig. 3 is the microstructure figure for the large single crystal nickel-cobalt lithium manganate cathode material that the embodiment of the present invention 1 is prepared；

Fig. 4 is the particle size distribution figure for the large single crystal nickel-cobalt lithium manganate cathode material that the embodiment of the present invention 1 is prepared；

Fig. 5 is the XRD diffraction spectrogram of large single crystal nickel-cobalt lithium manganate cathode material；

Fig. 6 is the gram volume of large single crystal nickel-cobalt lithium manganate cathode material；

Fig. 7 is that the button electricity of large single crystal nickel-cobalt lithium manganate cathode material recycles figure.

Specific embodiment

Invention is further described in detail combined with specific embodiments below.

Battery assembly is that the large single crystal positive electrode obtained using the present embodiment is assembled into button cell, specific work respectively Skill: positive electrode, acetylene black, Kynoar PVDF are weighed according to the mass ratio of 95:2.5:2.5, are uniformly mixed, are added NMP stir 4h, slurry is made, is then coated uniformly on aluminium foil, then 80 DEG C of vacuum bakeouts, tablettings, be cut into diameter 14mm Positive plate；In addition, being equipped with the lithium piece of diameter 16mm as cathode, 5 drop 1mol/L LiPFO4+DEC/EC (volumes of syringe dropwise addition Than being electrolyte for 1) mixed solution, microporous polypropylene membrane is diaphragm, and button cell is carried out in the glove box full of argon gas Assembling.