JP6479634B2 - Method for producing nickel lithium metal composite oxide - Google Patents

Description

  The present invention relates to a method for producing a nickel lithium metal composite oxide, a nickel lithium metal composite oxide obtained by the production method, a positive electrode active material comprising the same, a lithium ion battery positive electrode using the positive electrode active material, and a lithium ion battery.

  The spread of information terminal devices such as personal computers and mobile phones that can be used outdoors is largely due to the introduction of small, lightweight and high-capacity batteries. With the spread of hybrid vehicles, demand for high-performance, safe and durable batteries for vehicles is increasing. In addition, electric vehicles have also been realized by reducing the size and capacity of batteries. Many companies and research institutes have already entered the technological development of batteries installed in information terminal equipment and vehicles, especially lithium ion batteries, and fierce competition has been taking place. Market competition for information terminal equipment, hybrid cars, and EV cars In recent years, there has been a strong demand for lower-cost lithium-ion batteries, and the balance between quality and cost has become an issue.

  As a means for reducing the manufacturing cost of the final industrial product, firstly, cost reduction of members and materials constituting the product can be mentioned. Also in the lithium ion battery, cost reduction of the positive electrode, the negative electrode, the electrolyte, and the separator, which are essential components, is being studied. The positive electrode is a member in which a lithium-containing metal oxide called a positive electrode active material is disposed on the electrode. Lowering the cost of the positive electrode active material is indispensable for lowering the cost of the positive electrode and further reducing the cost of the battery.

  At present, a nickel-based active material that can be expected to have a high capacity as a positive electrode active material of a lithium ion battery is attracting attention. One typical nickel-based active material is a mixed metal oxide (LNCAO) containing cobalt and aluminum in addition to lithium and nickel. Lithium hydroxide is used as a lithium source for nickel-based active materials such as LNCAO.

  The present inventor has already proposed an LNCAO-based lithium ion battery positive electrode active material using lithium hydroxide as a raw material and a method for producing the same in Japanese Patent Application Nos. 2014-174149, 2014-174150, and 2014-174151 ( Patent Documents 1, 2, 3). In the firing step of the above production method, a composite oxide (LNO) of lithium and nickel is generated by a reaction in which nickel hydroxide and lithium hydroxide as main raw materials are represented by the following formula.

(Manufacture of LNO from nickel hydroxide and lithium hydroxide)
4Ni (OH) ₂ + 4LiOH + O ₂ → 4LiNiO ₂ + 6H ₂ O

  By the way, a nickel-based active material typified by LNCAO is manufactured using lithium hydroxide as a lithium source (Non-patent Document 1). As lithium hydroxide, what is industrially synthesized from lithium carbonate as a raw material by a reaction represented by the following formula is exclusively used (Non-patent Document 2). Naturally, the price of lithium hydroxide is higher than the price of lithium carbonate, which is the raw material.

(Production of lithium hydroxide from lithium carbonate)
Li ₂ CO ₃ (aqueous solution) + Ca (OH) ₂ (aqueous solution) → 2LiOH (aqueous solution) + CaCO ₃ (solid)

  As described above, there is an increasing demand for higher performance and lower cost of lithium ion batteries, and it is necessary to improve the performance and cost of each component of the lithium ion battery and the materials constituting each member. Has been. Similarly, a positive electrode active material containing LNO is also required to have high quality and low cost.

If LNO is synthesized starting from lower cost lithium carbonate (Li ₂ CO ₃ ), it is expected that the production cost of the positive electrode active material containing LNO can be reduced. It is theoretically possible to consistently perform the decomposition reaction of lithium carbonate into lithium oxide and / or lithium hydroxide and the reaction of lithium oxide and / or lithium hydroxide with a nickel compound. A series of reactions may be performed at a higher temperature at which the decomposition reaction of lithium carbonate into lithium oxide and / or lithium hydroxide is possible.

  However, in the production of a positive electrode active material for a lithium ion battery, lithium carbonate is used as a lithium source only for cobalt-based, manganese-based, nickel-cobalt-manganese ternary (NCM) active materials (non-patented). Literature 1, Patent Literature 4). Lithium cobalt oxide (LCO), which is typical as a cobalt-based positive electrode active material, is manufactured by mixing lithium carbonate, which is a raw material, and cobalt oxide and / or cobalt hydroxide, and synthesizing at a firing temperature around 1000 ° C. Can do. It is considered that a decomposition reaction of lithium carbonate into lithium oxide and / or lithium hydroxide occurs during this synthesis process. In the case of NCM, since it is necessary to raise the firing temperature to near the decomposition temperature of lithium carbonate, NCM is produced by high-temperature firing at 900 ° C. or higher.

  Patent Document 5 describes an example in which lithium hydroxide and lithium carbonate are used in combination as a lithium source. The production method described in Patent Document 5 is a method of producing a lithium transition metal composite oxide by spray drying a slurry containing a manganese compound, a cobalt compound, a nickel compound, and a lithium compound, and then firing the slurry. In this method, the lithium compound contains lithium hydroxide and lithium carbonate, the ratio of Li atoms derived from lithium carbonate to all Li atoms is 5 to 95 mol%, and after spray drying of the slurry, 600 ° C or higher, It is characterized by holding at a temperature lower than the melting point of lithium carbonate (726 ° C.) and then firing at a temperature higher than the melting point of lithium carbonate.

  Thus, there is no known production example of a nickel-based active material (typically LNO) using lithium carbonate as the only lithium source. The reason why such a manufacturing method is said to be difficult is considered that the layered structure of the LNO type composite oxide is unstable compared to the layered structure of other positive electrode active materials for lithium ion batteries such as cobalt. In the reaction at high temperature, the thermodynamic energy of the reaction system is increased, so that it is considered that the crystal structures of various composite oxides to be generated are disturbed. Specifically, the 3a site (lithium ion layer) and the 3b site (nickel ion layer) of the layered structure of LNO are ion-exchanged by thermal vibration at a high temperature, and nickel enters the lithium layer and lithium enters the nickel layer. An invading state, so-called cation mix, is induced. Therefore, it has been expected that the performance of the obtained positive electrode active material is lowered, and that only a positive active material with low practicality can be obtained. Since such a prediction was persuasive to those skilled in the art, a method for producing LNO type composite oxide for lithium ion battery positive electrode active material using lithium carbonate as a raw material has been hardly studied so far.

  The applicant has challenged the limitations of the prior art and has sought a method for producing an LNO-based positive electrode active material using only lithium carbonate as a lithium source, which has been considered impossible in the past. As a result, it was discovered that a positive electrode active material for a lithium ion battery having a performance meeting the requirements can be produced by performing the firing step in two stages, a high temperature firing step and a subsequent low temperature firing step, and a patent application has already been filed ( Patent Document 6).

  However, the performance of the lithium ion battery using the nickel lithium metal composite oxide produced by the method disclosed in Patent Document 6 as the positive electrode active material has room for further improvement. For example, satisfactory performance was not obtained in terms of discharge capacity and initial efficiency.

Japanese Patent Application No. 2014-174149 Japanese Patent Application No. 2014-174150 Japanese Patent Application No. 2014-174151 International Publication No. 2009/060603 JP-A-2005-324973 Japanese Patent Application No. 2014-244059

Japan Oil, Gas and Metals National Corporation 2012 Report 148-154 "Monthly Fine Chemical" November 2009, pages 81-82, CM Publishing

  Thus, the manufacturing method of the nickel-type positive electrode active material for lithium ion batteries which uses lithium carbonate as the only lithium source is not examined enough, and there exists room for improvement. Accordingly, the present inventor has continued to further improve the nickel-based positive electrode active material using lithium carbonate as a raw material and a method for producing the same, aiming at higher performance and lower cost of the lithium ion battery positive electrode active material.

  That is, the present inventors have intensively studied for a method for producing a nickel lithium metal composite oxide that exhibits better battery performance when used as a positive electrode material of a lithium ion battery.

  As a result, by compressing the raw material to be fired before the firing step and firing the raw material in a compressed state as it is, a nickel lithium metal composite that provides better lithium ion battery performance when used as a positive electrode material The oxide was successfully produced in high yield.

That is, the present invention is as follows.
(Invention 1) Lithium carbonate is used as a lithium raw material,
Including the following step 1 and / or step 1 ′, step 2 and step 3,
The manufacturing method of the nickel lithium metal complex oxide represented by the following formula | equation (1).
(Step 1) A precursor containing nickel hydroxide and / or nickel oxide, cobalt hydroxide and / or cobalt oxide, metal M hydroxide and / or metal M oxide, and carbonic acid Mixing step of mixing lithium.
(Step 1 ′) a precursor containing nickel hydroxide and / or nickel oxide, cobalt hydroxide and / or cobalt oxide, and metal M hydroxide and / or metal M oxide, Mixing step of mixing lithium carbonate.
(Step 2) A step of compressing the mixture obtained in Step 1 and / or Step 1 ′.
(Step 3) A step of firing the compression-molded product of the mixture that has undergone step 2 in a temperature range of 500 ° C. to 850 ° C. for 3 to 40 hours.

（式（１）中、０．９０＜ａ＜１．１０、１．７＜ｂ＜２．２、０．０１＜ｘ＜０．１５、かつ０．００５＜ｙ＜０．１０であり、ＭはＡｌを必須元素として含み、Ｍｎ、Ｗ、Ｎｂ、Ｍｇ、Ｚｒ、及びＺｎから選ばれる元素を含んでもよい金属である。）

(In formula (1), 0.90 <a <1.10, 1.7 <b <2.2, 0.01 <x <0.15, and 0.005 <y <0.10, M is a metal that contains Al as an essential element and may contain an element selected from Mn, W, Nb, Mg, Zr, and Zn.)

  (Invention 2) The method for producing a nickel lithium metal composite oxide according to Invention 1, wherein the mixture obtained in Step 1 and / or Step 1 'in Step 2 is compressed under a load of 10 kN or more.

  (Invention 3) The nickel-lithium metal composite oxidation of Invention 1 or Invention 2, wherein the mixture obtained in Step 1 and / or Step 1 ′ is compressed using a granulator, a pellet molding machine, or a tableting machine in Step 2. Manufacturing method.

(Invention 4) A nickel-lithium metal composite oxide obtained through Step 3,
The 0.1 C discharge capacity of a lithium ion battery comprising a positive electrode provided with a dried coating film of a positive electrode active material mixture containing the nickel lithium metal composite oxide, carbon black, and a binder, and a negative electrode made of lithium metal is 190 mAh / g or more, and
The initial charge / discharge efficiency of a lithium ion battery comprising a positive electrode provided with a dried coating film of a positive electrode active material mixture containing the nickel lithium metal composite oxide, carbon black, and a binder, and a negative electrode made of lithium metal is 87%. It functions as a lithium ion battery positive electrode active material,
The manufacturing method of the nickel lithium metal complex oxide of any one of invention 1-3.

  (Invention 5) The invention according to any one of Inventions 1 to 4, further comprising a step of crushing the fired body obtained in Step 3 and / or a step of sieving the fired body after Step 3 after Step 3. Method for producing a nickel lithium metal composite oxide.

  (Invention 6) A compression-molded body of nickel-lithium metal composite oxide represented by the following formula (1):

（式（１）中、０．９０＜ａ＜１．１０、１．７＜ｂ＜２．２、０．０１＜ｘ＜０．１５、かつ０．００５＜ｙ＜０．１０であり、ＭはＡｌを必須元素として含み、Ｍｎ、Ｗ、Ｎｂ、Ｍｇ、Ｚｒ、及びＺｎから選ばれる元素を含んでもよい金属である。）
粒子、ペレット、またはタブレットの形状であり、
さらに、
該圧縮成形体の解砕物とカーボンブラックとバインダーとを含む正極活物質合剤の塗膜乾燥物を備える正極と、リチウム金属からなる負極とを備えるリチウムイオン電池の０．１Ｃ放電容量が１９０ｍＡｈ／ｇ以上であり、かつ、
該圧縮成形体の解砕物とカーボンブラックとバインダーとを含む正極活物質合剤の塗膜乾燥物を備える正極と、リチウム金属からなる負極とを備えるリチウムイオン電池の初回の充放電効率が８７％以上であるリチウムイオン電池正極活物質として機能する、
ニッケルリチウム金属複合酸化物の圧縮成形体。

(In formula (1), 0.90 <a <1.10, 1.7 <b <2.2, 0.01 <x <0.15, and 0.005 <y <0.10, M is a metal that contains Al as an essential element and may contain an element selected from Mn, W, Nb, Mg, Zr, and Zn.)
In the form of particles, pellets, or tablets,
further,
The 0.1 C discharge capacity of a lithium ion battery comprising a positive electrode comprising a pulverized product of the compression-molded product, a coating film of a positive electrode active material mixture containing carbon black and a binder, and a negative electrode made of lithium metal is 190 mAh / g or more, and
First-time charge / discharge efficiency of a lithium ion battery comprising a positive electrode comprising a pulverized product of the compression-molded product, a coating film dried of a positive electrode active material mixture containing carbon black and a binder, and a negative electrode made of lithium metal is 87%. It functions as a lithium ion battery positive electrode active material,
Nickel-lithium metal composite oxide compression molding.

  (Invention 7) A compression-molded body of nickel-lithium metal composite oxide according to claim 6, which is obtained by the method for producing a nickel-lithium metal composite oxide according to any one of inventions 1 to 5.

  (Invention 8) A crushed product of a compression molded article of the nickel lithium metal composite oxide of Invention 6 or Invention 7.

  (Invention 9) A positive electrode active material comprising a pulverized product of the compression molded product of the nickel lithium metal composite oxide of Invention 8.

  (Invention 10) A positive electrode mixture for a lithium ion battery comprising the positive electrode active material of Invention 9.

  (Invention 11) A positive electrode for a lithium ion battery using the positive electrode mixture for a lithium ion battery according to Invention 10.

  (Invention 12) A lithium ion battery comprising the positive electrode for a lithium ion battery according to Invention 11.

  If the method for producing a nickel lithium metal composite oxide of the present invention is used, more excellent battery performance can be obtained when the obtained nickel lithium metal composite oxide is used as a positive electrode active material of a lithium ion battery.

  By the production method of the present invention, a nickel lithium metal composite oxide represented by the following formula (1) is obtained. M in the formula (1) is a metal element that contains Al as an essential element and may contain a metal selected from Mn, W, Nb, Mg, Zr, and Zn. The amount of one or more kinds of metals selected from Mn, W, Nb, Mg, Zr and Zn, which are optional constituent elements, is a nickel-based positive electrode active material of a nickel-lithium metal composite oxide represented by the formula (1) As long as it does not impair the function, any method may be used.

  The time when one or more kinds of metals selected from Mn, W, Nb, Mg, Zr, and Zn are supplied to the nickel-lithium metal composite oxide may be any step of the production method of the present invention. For example, it may be supplied as an impurity contained in the raw material, may be supplied as a sub-component in the below-described step 1 or step 1 ′ which is an essential step, or may be supplied in an arbitrary step.

_{Li a Ni 1-x-y} Co x M y O b ··· (1)
(In the formula (1), 0.90 <a <1.10, 1.7 <b <2.2, 0.01 <x <0.15, 0.005 <y <0.10, M is Al or Al containing one or more trace amounts of metals selected from Mn, W, Nb, Mg, Zr, and Zn.)

  In the present invention, first, in step 1 and / or step 1 ', the metal raw materials constituting the nickel lithium metal composite oxide are mixed. The obtained mixture is fired in Step 2 described later to obtain the target nickel lithium metal composite oxide. Below, each process of the manufacturing method of this invention is demonstrated. In order to briefly explain the operation of each step and the chemical reaction occurring in each step, an example in which M in formula (1) is Al will be described. The production method in the case where M in formula (1) contains a metal other than Al follows this example.

  (Step 1) A precursor containing nickel hydroxide and / or nickel oxide, cobalt hydroxide and / or cobalt oxide, metal M hydroxide and / or metal M oxide, and carbonic acid It is a mixing step of mixing lithium. Lithium carbonate is a raw material for lithium hydroxide (usually lithium hydroxide monohydrate). As described above, in the prior art, lithium hydroxide has been used as a raw material for the nickel lithium metal composite oxide. Compared with price per unit weight, lithium carbonate is cheaper than lithium hydroxide. Compared with lithium content per unit weight, lithium carbonate contains a higher concentration of lithium than lithium hydroxide monohydrate. Thus, the use of lithium carbonate is advantageous. Mixing is performed using various mixers and applying a shearing force.

  (Step 1 ′) a precursor containing nickel hydroxide and / or nickel oxide, cobalt hydroxide and / or cobalt oxide, and metal M hydroxide and / or metal M oxide, It is a mixing process of mixing lithium carbonate. As described in Step 1, the use of lithium carbonate is advantageous in terms of production cost. Mixing is performed using various mixers and applying a shearing force.

  The raw material mixture obtained in the mixing step of the present invention is used in Step 2 described later. The firing material used in Step 2 was prepared in Step 1 ′ with the mixture prepared in Step 1, whether it was only the mixture prepared in Step 1 or only the mixture prepared in Step 1 ′. A mixture obtained by further mixing the mixture may be used.

  (Step 2) A step of compressing the mixture obtained in step 1 and / or step 1 '. “Compression” as used herein refers to an operation of pressing the mixture until the voids between the secondary particles are reduced to a state where the secondary particles of the mixture obtained in step 1 and / or step 1 ′ are not destroyed. Point to. In terms of easy transport of the mixture to step 3 (baking step) described later, as such a compression operation, a granulator, a pellet molding machine, or a tableting machine is used, and the mixture is 10 kN or more. So-called granulation, pellet molding, and tableting, which are preferably formed into granules or tablets with a pressing force of 25 to 400 kN, more preferably 50 to 250, are preferable. The shape and size of the mixture after compression are not particularly limited, but pellets or tablets having a longest diameter of 0.3 mm to 15 mm are preferable in that they are efficiently and uniformly heated in the subsequent baking step and have good handleability. preferable.

  A granulator, a pellet molding machine, or a tableting machine is preferable as an apparatus used for compression in that it can be efficiently operated according to the amount of the mixture. When the mixture obtained in Step 1 and / or Step 1 ′ is agglomerated or contains a large amount of moisture, the product obtained by appropriately drying, mixing or kneading the mixture in advance in Step 2 may be compressed. it can. The granulator, pellet molding machine, or tableting machine may have a combination of drying, mixing, and kneading functions. As such a compression device, for example, a high-pressure granulator or a granulation mixer is used.

  (Step 3) This is a step of firing the compression-molded body obtained in Step 2. In the firing step of the present invention, the firing is performed in a temperature range of 500 ° C. to 850 ° C., preferably in a temperature range of 600 ° C. to 810 ° C., usually for 3 to 40 hours, preferably 5 to 35 hours. In step 3, the firing in step 3 is preferably performed in the presence of oxygen. As the firing atmosphere gas, pure oxygen, air, a mixed gas obtained by adding oxygen to air, or a gas obtained by adding oxygen to an inert gas such as nitrogen can be used.

  When the firing temperature is less than 500 ° C., a large amount of unreacted lithium carbonate remains and the production efficiency of the nickel lithium metal composite oxide is lowered. In addition, when the nickel-lithium metal composite oxide produced by firing at such a low temperature is used as a positive electrode active material for a lithium ion battery, sufficient battery performance cannot be obtained. When the firing temperature exceeds 850 ° C., unreacted lithium carbonate decreases, but when the produced nickel-lithium metal composite oxide is used as a positive electrode active material for a lithium ion battery, sufficient battery performance cannot be obtained.

  Step 3 is performed in one stage, that is, the firing can be completed while maintaining a temperature of 500 ° C. or higher. Alternatively, the firing can be completed in two or more stages, that is, by maintaining each at a different temperature of 500 ° C. or more for a certain time. One-step or two-step temperature setting is realistic.

  The firing furnace used in step 3 is not limited as long as it has a structure capable of inflow and exhaust of the firing atmosphere gas as described above. A preferred firing furnace is a continuous or batch furnace capable of firing a relatively large amount of a raw material mixture intended for commercial production. For example, a rotary kiln, a roller hearth kiln, a muffle furnace, etc. can be used. In order to efficiently introduce the oxidizing gas, a structure in which the supply port and the discharge port of the firing atmosphere gas are close to the container opening is preferable. A structure that can be fired while stirring the mixture in the container is preferable in that the mixture can be fired uniformly.

  After step 3, a step of crushing the fired body using a ball mill, jet mill, mortar, or the like can be provided. Further, after step 2, a step of sieving the fired body particles obtained in step 2 may be provided. You may perform both such a crushing process and a sieving process. By such a pulverization step and / or a sieving step, a fine-particle nickel-lithium metal composite oxide with adjusted fillability and particle size distribution can be produced. The nickel lithium metal composite oxide of the present invention is finally adjusted to have a median diameter of preferably 20 μm or less, more preferably 3 to 18 μm.

  At the end of step 3, the lithium carbonate is almost completely consumed to form a nickel lithium metal composite oxide. As a result, a nickel lithium metal composite oxide having excellent performance as a positive electrode active material can be obtained. The performance of the nickel lithium metal composite oxide obtained by the method of the present invention can be confirmed by the following evaluation.

(Discharge capacity)
The 0.1 C discharge capacity of a lithium ion battery comprising a positive electrode obtained by applying a positive electrode active material in which carbon black is mixed with nickel lithium metal composite oxide obtained by the production method of the present invention and a negative electrode made of lithium metal is 190 mAh / g or more.

(Charge / discharge characteristics)
The initial charge and discharge efficiency of a lithium ion battery comprising a positive electrode obtained by applying a positive electrode active material in which carbon black is mixed with nickel lithium metal composite oxide obtained by the production method of the present invention and a negative electrode made of lithium metal is 87% or more. It is.

  According to the present invention, there is provided a nickel lithium metal composite oxide suitable as a positive electrode active material of a lithium ion battery using lithium carbonate as a raw material. The positive electrode active material of a lithium ion battery may be composed of only the nickel lithium metal composite oxide of the present invention, or another nickel lithium metal composite oxide may be mixed with the nickel lithium metal composite oxide of the present invention. . For example, a mixture of 50 parts by weight of the nickel lithium metal composite oxide powder of the present invention and 50 parts by weight of a positive electrode active material for a lithium ion battery secondary battery other than the present invention can be used as the positive electrode active material. When producing a positive electrode of a lithium ion battery, a positive electrode active material containing the above-described nickel lithium metal composite oxide powder of the present invention, a conductive additive, a binder, and an organic solvent for dispersion are added to prepare a positive electrode mixture slurry. It is prepared and applied to an electrode to produce a lithium ion battery positive electrode.

Example 1
The nickel lithium metal composite oxide of the present invention was manufactured through the following Step 1, Step 2, and Step 3.
(Process 1) Aluminum hydroxide and lithium carbonate were mixed with a precursor having an average particle diameter of 13.6 μm composed of nickel hydroxide and cobalt hydroxide prepared from an aqueous solution of nickel sulfate and cobalt sulfate by shearing with a mixer. . The aluminum hydroxide was prepared so that the aluminum content was 2 mol% with respect to the precursor amount, and the lithium carbonate was prepared so that the molar ratio with respect to the total of nickel-cobalt-aluminum was 1.025.
(Step 2) Using a roll type high-pressure granulator “Bricketta” manufactured by Shinto Kogyo Co., Ltd., the mixture obtained in Step 1 was compressed into a disk-shaped pellet having a diameter of 5 mm.
(Step 3) The pellets obtained in Step 2 were fired at 810 ° C. for 10 hours while supplying 5 liters of pure oxygen per minute. Thus, the nickel lithium metal composite oxide of the present invention was obtained. The nickel-lithium metal composite oxide after firing maintained the shape of the disk-shaped pellet.

(Example 2) The nickel lithium metal composite oxide of the present invention was produced through the following steps 1, 2, and 3.
(Step 1) Performed in the same manner as in Example 1.
(Step 2) Performed in the same manner as in Example 1.
(Step 3) The pellets obtained in Step 2 were fired at 690 ° C. for 10 hours while supplying 5 liters of pure oxygen per minute. Thereafter, the temperature was raised and firing was performed at 810 ° C. for 5 hours. Thus, the nickel lithium metal composite oxide of the present invention was obtained. The nickel-lithium metal composite oxide after firing maintained the shape of the disk-shaped pellet.

(Example 3)
The nickel lithium metal composite oxide of the present invention was manufactured through the following Step 1, Step 2, and Step 3.
(Step 1) Performed in the same manner as in Example 1.
(Step 2) Performed in the same manner as in Example 1.
(Step 3) The pellets obtained in Step 2 were fired at 690 ° C. for 10 hours while supplying 5 liters of pure oxygen per minute. Thereafter, the temperature was raised and firing was performed at 780 ° C. for 5 hours. Thus, the nickel lithium metal composite oxide of the present invention was obtained. The nickel-lithium metal composite oxide after firing maintained the shape of the disk-shaped pellet.

(Comparative Example 1)
Step 1 was performed in the same manner as in Example 1. The mixture obtained in step 1 was immediately fired without being compressed to produce a nickel lithium metal composite oxide. In the firing step, while supplying pure oxygen of 5 liters per minute, first, firing was performed at 690 ° C. for 10 hours, and then the temperature was raised and firing was performed at 730 ° C. for 10 hours. Thus, a nickel-lithium metal composite oxide for comparison was manufactured. The nickel-lithium metal composite oxide after firing was an agglomerated massive fired body.

(Comparative Example 2)
The mixture obtained in the above step 1 was immediately fired without compression to produce a nickel lithium metal composite oxide. In the firing step, while supplying 5 liters of pure oxygen per minute, first, firing was performed at 690 ° C. for 10 hours, and then the temperature was raised and firing was performed at 750 ° C. for 10 hours. Thus, a nickel-lithium metal composite oxide for comparison was manufactured. The nickel-lithium metal composite oxide after firing was an agglomerated massive fired body.

(Evaluation of battery performance)
With respect to 100 parts by weight of the pulverized nickel lithium metal composite oxide obtained in Examples and Comparative Examples, 1 part by weight of dentylene acetylene black, 5 parts by weight of graphite carbon made of Japanese graphite, 4 parts by weight of polyvinylidene fluoride made by Kureha, A slurry was prepared using N-methylpyrrolidone as a dispersion solvent. This slurry was applied to an aluminum foil as a current collector, dried and pressed to form a positive electrode, and a lithium metal foil as a negative electrode as a counter electrode to form a 2032 type coin battery. The discharge capacity and initial efficiency at 0.1 C of this battery were measured. The results are shown in Table 1.

  As shown in the results of Table 1, when the nickel lithium metal composite oxide obtained by the production method of the present invention is used as a positive electrode active material of a lithium ion battery, excellent discharge capacity and initial efficiency are achieved. . Although Example 1 and Example 2 and Example 3 differ in firing conditions, equivalent battery performance is obtained. On the other hand, in Comparative Examples 1 and 2 in which the nickel-lithium metal composite oxide obtained by firing the mixture obtained in Step 1 without compression was used as the positive electrode active material of the lithium ion battery, the discharge capacity and the initial Both efficiency is inferior.

  As described above, in the method for producing a nickel lithium metal composite oxide of the present invention, it is possible to produce a nickel lithium metal composite oxide having excellent performance as a positive electrode active material by using low-cost lithium carbonate as a raw material.

  The present invention is useful as a means for supplying a high-performance lithium ion battery at a low cost. The nickel lithium metal composite oxide obtained in the present invention and a lithium ion battery using the same contribute to further cost reduction of a portable information terminal and a battery-equipped vehicle.

Claims (12)

Lithium carbonate is used as a lithium raw material,
Including the following step 1 and / or step 1 ′, step 2 and step 3,
The manufacturing method of the nickel lithium metal complex oxide represented by the following formula | equation (1).
(Step 1) A precursor containing nickel hydroxide and / or nickel oxide, cobalt hydroxide and / or cobalt oxide, metal M hydroxide and / or metal M oxide, and carbonic acid A mixing step of obtaining a mixture by mixing lithium.
(Step 1 ′) a precursor containing nickel hydroxide and / or nickel oxide, cobalt hydroxide and / or cobalt oxide, and metal M hydroxide and / or metal M oxide, A mixing step in which a mixture is obtained by mixing lithium carbonate.
(Step 2) A step of obtaining a compression molded body by compressing the mixture obtained in Step 1 and / or Step 1 ′.
(Step 3) A step of obtaining a fired product by firing the compression molded product of the mixture that has undergone Step 2 in a temperature range of 500 ° C. to 850 ° C. for 3 to 40 hours.

(In formula (1), 0.90 <a <1.10, 1.7 <b <2.2, 0.01 <x <0.15, and 0.005 <y <0.10, M is a metal that contains Al as an essential element and may contain an element selected from Mn, W, Nb, Mg, Zr, and Zn.)   The method for producing a nickel-lithium metal composite oxide according to claim 1, wherein the mixture obtained in step 1 and / or step 1 'in step 2 is compressed by applying a load of 10 kN or more.   The nickel-lithium metal composite oxide according to claim 1 or 2, wherein the mixture obtained in step 1 and / or step 1 'is compressed using a granulator, a pellet molding machine, or a tableting machine in step 2. Production method. The fired body obtained through step 3 is
A 0.1 C discharge capacity of a lithium ion battery comprising a positive electrode provided with a dried coating film of a positive electrode active material mixture containing nickel lithium metal composite oxide, carbon black and a binder, and a negative electrode made of lithium metal is 190 mAh / g. That's it, and
First-time charge / discharge efficiency of a lithium ion battery comprising a positive electrode provided with a dried coating film of a positive electrode active material mixture containing nickel lithium metal composite oxide, carbon black and a binder, and a negative electrode made of lithium metal is 87% or more. Which functions as a lithium ion battery positive electrode active material,
The manufacturing method of the nickel lithium metal complex oxide of any one of Claims 1-3.   The nickel according to any one of claims 1 to 4, further comprising a step of crushing the fired body obtained in step 3 and / or a step of sieving the fired body after step 3 after step 3. A method for producing a lithium metal composite oxide. A nickel lithium metal composite oxide compression molded body represented by the following formula (1):

(In formula (1), 0.90 <a <1.10, 1.7 <b <2.2, 0.01 <x <0.15, and 0.005 <y <0.10, M is a metal that contains Al as an essential element and may contain an element selected from Mn, W, Nb, Mg, Zr, and Zn.)
In the form of particles, pellets, or tablets,
further,
The 0.1 C discharge capacity of a lithium ion battery comprising a positive electrode comprising a pulverized product of the compression-molded product, a coating film of a positive electrode active material mixture containing carbon black and a binder, and a negative electrode made of lithium metal is 190 mAh / g or more, and
First-time charge / discharge efficiency of a lithium ion battery comprising a positive electrode comprising a pulverized product of the compression-molded product, a coating film dried of a positive electrode active material mixture containing carbon black and a binder, and a negative electrode made of lithium metal is 87%. It functions as a lithium ion battery positive electrode active material,
Nickel-lithium metal composite oxide compression molding.   The compression molded article of the nickel lithium metal composite oxide according to claim 6, which is obtained by the method for producing a nickel lithium metal composite oxide according to any one of claims 1 to 5.   A crushed product of a compression-molded body of the nickel-lithium metal composite oxide according to claim 6 or 7.   A positive electrode active material comprising a pulverized product of the compression-molded body of the nickel lithium metal composite oxide according to claim 8.   A positive electrode mixture for a lithium ion battery, comprising the positive electrode active material according to claim 9.   The positive electrode for lithium ion batteries using the positive mix for lithium ion batteries of Claim 10.   A lithium ion battery comprising the positive electrode for a lithium ion battery according to claim 11.