TW200532961A - Lithium cobaltate, its preparation method, and non-aqueous electrolyte secondary battery - Google Patents

Abstract

The present invention provides lithium cobaltate which is excellent in load characteristics and blister inhibition and is useful as a positive electrode active material in a non-aqueous electrolyte secondary battery, its preparation process, and a non-aqueous electrolyte secondary battery using a positive electrode active material containing the same. The lithium cobaltate is obtained from cobalt oxyhydroxide and a lithium compound and has an average particle size of 10-15 μm and a residual lithium carbonate content of ≤ 0.1 wt.%. In the preparation method of the lithium cobaltate, cobalt oxyhydroxide having an angle of repose of ≤ 50 DEG and a tap density of 1.3-1.8 g/cm3 is mixed with the lithium compound and subsequently baked.

Description

200532961 发明 Description of the invention: [Technical field to which the invention belongs] The present invention relates to a lithium-cobalt composite oxide and a method for manufacturing the same, a non-aqueous electrolyte secondary battery, and an electronic device for carrying. [Previous technology] In recent years, with the rapid development of mobile and wireless home appliances, non-aqueous electrolytic cell batteries have been put into practical use as power sources for small electronic devices such as laptop personal computers, mobile phones, and video cameras. So far, various improvements have been made in the related lithium cobaltate to improve battery characteristics. For example, a positive electrode active material f Lic002 (see Patent Document 1) is proposed, so that the residual amount of Li2C003 in the positive electrode active material Lic002 is ι0% by weight or less. Furthermore, a non-aqueous electrolyte secondary battery (see Patent Documents) was proposed: LiaM02 (the "selected from at least one of the transition metals' 0.05Sa 1.1% each") of the Hai battery positive electrode was coated with carbonic acid lithium.

Furthermore, a method for producing lithium cobalt oxide particle powder (see: Reference 3) is proposed, in which the starting hydroxide powder is fired under an oxygen-containing gas at a temperature of 300 to 3,000 to produce a bile specific surface area. : Cobalt oxide microcrystalline particle powder 'Second' This cobalt particle powder ㈣ compound is mixed and wound in an oxygen-containing gas. Patent Document 1: Japanese Patent Application Laid-Open No. 4-56〇64 Patent Document 2: Japanese Patent Application Laid-Open No. 4- Japanese Patent Publication No. 329268 Patent Document 3: Japanese Unexamined Patent Application Publication No. 0-324522 6 200532961 [Summary of the Invention] However, at this stage, even if the above-mentioned method is adopted, sufficient battery performance cannot be satisfied. In particular, it is required to improve safety, battery capacity, load characteristics, and improvement of swelling suppression of aluminum laminated batteries. Therefore, an object of the present invention is to provide a method for manufacturing a lithium-cobalt composite oxide; and a non-aqueous electrolyte secondary battery whose positive electrode active material contains the lithium-cobalt composite oxide. When the lithium-cobalt composite oxide is used as a positive electrode active material of a non-aqueous electrolyte secondary battery, it has particularly excellent load characteristics and swelling suppression properties. The present invention more specifically provides the following. (1) A lithium-cobalt composite oxide, characterized in that it is a lithium-cobalt composite oxide prepared from a basic hydroxide and a bell compound, and the average particle size of the lithium-cobalt composite oxide ranges from 10 to 15 μm And the remaining amount of lithium carbonate is 0.001% by weight or less. (2) A method for producing a bell-cobalt composite oxide, which is characterized in that a lithium-cobalt composite oxide is obtained by mixing the cobalt hydroxide of the formula with a lithium compound and then firing the lithium-cobalt composite oxide. (Angles of repose) is 50 degrees or less, and tap density is 1.3 to 1.8 g / cm3. (3) The method for producing a lithium-cobalt composite oxide according to (2), wherein the basic cobalt hydroxide is a secondary particle formed by agglomerating primary particles of 0.1 to 3 μm, and the secondary particles The average particle diameter is 8 to 18 μm. (4) A non-aqueous electrolyte secondary battery, characterized in that the positive electrode active material contained in the positive electrode is the lithium-cobalt composite oxide according to (1). 200532961 (5) —A portable electronic device The non-aqueous electrolyte secondary battery. It is characterized by being equipped with (4) [Embodiment] Hereinafter, the present invention will be described in detail. = Mingzhihao composite oxide, which is characterized by a osmium complex oxide prepared with a bell compound. The average particle size range of the rhenium complex oxide is 10-15, and the residual amount of lithium carbonate is 〇i weight. %the following. · The average particle size is 10 to 15 μm, preferably 10 to 13 μm. The "average particle size" of the present invention represents a cumulative 50% (D50) value of the particle size distribution measured by a laser particle size distribution measuring device. Once again, another feature is that the residual amount of lithium carbonate in the lithium-cobalt composite oxide is not more than 0.1% by weight, and preferably not more than 0.05% by weight. Li-Co complex oxide LiaCobMcOdNe (In the chemical formula i, m is selected from at least transition metal elements other than Co and Ni, elements of Groups 2, 13 and 15 of the periodic table. 1 element; ^ system ^ element atom a system 〇 $ 1.25, b system 0.995 $ 1.05, c system 〇 ″ 05, d system, e system 〇Se $ 〇.05) composition lithium shown Gasification. '' In the lithium-cobalt composite oxide of the present invention, the M element may be selected from B, Mg, and y

Cu, Ce, Y, Ti, V, Mn, Fe, Sn, Zr, Sb, Nb, Ru, pb, Ta, La, Pr, and Nd are at least one element in the group. In addition, the element element contained in the lithium-cobalt composite oxide may be exemplified by gas 200532961 or bromine ', and fluorine is preferred. The content of the halogen element is 0.005 to 2.5% by weight, and more preferably 0.05 to 1.5% by weight. Furthermore, the average particle diameter of the lithium-cobalt composite oxide of the present invention is M ~ 15, preferably 10 ~ 13 μm. The measurement of the average particle size is represented by the cumulative 50% (D50) value of the particle size distribution measured by the laser particle size distribution measuring device. The method for producing a bell oxide compound oxide according to the present invention is characterized in that the test compound hydroxide is mixed with a bell compound and then fired to obtain a lithium-cobalt compound oxide. The degree of taper is less than or equal to 1 · 3 to 1 · 8g / cm3. Cobalt hydroxide may be CoOH as the main component, but it may also contain CO03, CO03, and the like. The lithium-cobalt composite oxide is agglomerated with secondary particles of claws to form secondary particles, and the average particle diameter of the secondary particles is preferably 8 to 18 μπ]. The so-called "agglomeration of primary particles to form secondary particles" can be confirmed by s-sheet observation. In the production method of the present invention, there are no particular restrictions on the production method of the basic cobalt hydroxide. For example, after oxidizing a divalent cobalt compound such as cobalt nitrate, cobalt chloride, and cobalt sulfate with an oxidant, and then using neutralization, the above-mentioned oxidant is not particularly limited. Examples include air, oxygen, and ozone. 'Perbellic acid (H_4) and salts represented by M3Mn〇4 and the like; chromic acid (c ΜM3 r η 〇3 J ^ 2 2 Γ207, M 2Cr〇4, M3Cr03X, Cr〇2X2, etc. Related and related compounds: compounds; F2, Cl2, Br2, "Isofunctional elements; h2202, 102, fluorene and other superemulsions, peroxyacid and M32S2G8, M32SG5, H2CG3, (H3CG3H, etc. 200532961 compounds shown Or its salts; oxo acids and M3MC10, M3BrO, M3IO0, M3Cl03, M3Br03, M3I〇3, m3C104, m3I04, Na3H2I06, KI04, etc. or their salts, etc. In the formula, M3 It refers to an alkali metal element. The above-mentioned alkali metal is not particularly limited, and examples thereof include bell, sodium, potassium, tear, etc. In addition, X refers to a halogen element. The base used for neutralization is not particularly limited, and may be appropriately used. Uses such as bell hydroxide, hydroxide, potassium hydroxide, hydroxide, thorium hydroxide, barium oxychloride, hydroxide Aqueous solution of inorganic hydroxides such as ammonium, etc. The above-mentioned experimental formula can be used to dissolve compounds with j-valent cobalt, such as sodium hydroxide, chloride, and sulfuric acid, in water to form an aqueous solution. The above-mentioned base can be obtained by simultaneously performing neutralization and oxidation. In addition, the above-mentioned base can also be added to an aqueous solution containing the above-mentioned divalent cobalt compound to synthesize a divalent cobalt hydroxide, and then an oxidant is added for oxidation, The above-mentioned basic cobalt hydroxide can still be obtained. Even after the above-mentioned oxidant is added to the above-mentioned aqueous solution with a divalent cobaltate, the alkali is added to perform neutralization, and the above-mentioned basic cobalt hydroxide can still be obtained. Lithium compounds will be used in the manufacturing method. Lithium compounds are not particularly limited, and inorganic salts such as lithium oxide, lithium carbonate, and lithium nitrate can be appropriately used. In the case of bell compounds, because bell carbonate is industrially available and inexpensive, Therefore, the lithium compound concentration is preferably the one with the highest purity. The production method of the present invention, for example, firstly combines the above-mentioned basic cobalt hydroxide with a lithium compound (preferably lithium carbonate). They are mixed to obtain a mixture. Mixing can be made by: either dry or wet methods. It is better to use the begging method if it is easy to manufacture. When dry mixing is used, it is better to use raw materials. 200532961 Blending machine for homogeneous mixing. The mixing ratio of a and fengshan is based on the combination of ec > m_ and the initial chemical compound, preferably 〜5 atomic moerca.

t, ^ 85 / ^ 合 "line firing. The firing temperature is preferably TWO 2 l0le! ^^, nephew. Right firing temperature is lower than 70 (rc, will be lithium-cobalt composite oxidation It is best to avoid the basic lice of cobalt oxide or lithiation of the caterpillars in the farmland. Therefore, if the firing temperature is higher than U00H, the lithium-cobalt composite oxide will Start " Clock used for positive electrode active materials_Two pairs: ^ Oxide is used as electricity at the end of electricity "causes capacitance; :: = is particularly due to release, so it is best to avoid ... It can be applied in the air or oxygen ring, and there are no special restrictions. After firing, it should be properly cooled and matched with a tablet mouth to yoke and pulverize to obtain lithium-cobalt complex. 'The comminution that needs to be carried out is suitable when the tritium complex oxide obtained by the tick formation is a fragile bond. ^ Production method of lithium secondary batteries The positive electrode active material of the lithium secondary battery uses the above lithium-cobalt composite oxide. .The positive electrode activity 4 is not as described below. Material, conductive agent, binder, and the required mixture of fillers, etc.) as a raw material. The lithium secondary battery positive electrode active material of the present invention is composed of the above-mentioned lithium-cobalt composite oxide, so it should be used in conjunction with other When the raw materials are mixed together to prepare a positive electrode mixture, mixing is easier. When the positive electrode mixture obtained in 200532961 is applied to a positive electrode current collector, the coating processability is better. The lithium secondary battery of the present invention uses the above-mentioned lithium. Cobalt composite oxide positive electrode: It is composed of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a bell salt. The positive electrode is formed by coating a positive electrode on a positive electrode current collector and drying the positive electrode. The composition of the positive electrode active material, the conductive material, the mixture, and the filler to be added, etc. n ^ As long as the positive electrode current collecting system does not cause the formation of a conductive body in the battery, the rest is not particularly critical, and examples include ·· Do not record steel,: ,, Shao, titanium, fired carbon, inscription, or do not record steel treated with carbon, copper, zinc, or bank surface, etc. Also conductive agents can be: natural graphite And artificial graphite and other conductive materials such as graphite, carbon black, acetylene black, carbon fiber, carbon nano tube, or metal, powder, etc. 'natural graphite' can include, for example, scaly graphite, scaly graphite, and =. Use it alone or in combination of two or more kinds, and the mixing ratio of the agent, # 于 等 笔 2Marriage%. 50% weight in the positive electrode mixture is preferred, and the binder can be exemplified by: Ethyl alcohol, 2 propyl cellulose, regenerated cellulose, diethyl cellulose, polyethylene glycol x alkyl ketone ethylene-propylene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, oxygen Polysaccharides such as rubber and polyethylene oxide, polymers that can be used to heat Γ2 boxes with rubber elasticity, etc. These can be used alone or in groups of 5 or more. The compounding ratio of the adhesive is at plus 2, weight % ′ Is preferably 5 to 15% by weight. J 200520052961 q It is necessary to add in the electrode mixture in order to suppress the volume expansion of the positive electrode and the like. The filler may be a fibrous material that is not compounded in the battery to be composed, and fibers such as polypropylene chemically modified polymer, glass, and carbon may be used. Filling 1, and other olefins is preferred to account for G to 3G by weight in the positive electrode mixture. / 4, 0 篁 is not particularly limited: the anode is formed by coating a negative electrode material on a negative electrode current collector. The negative electrode current collecting system only needs to be formed in the battery: a conductive body, and the rest does not have a special change in I # θ t chemical change. For example, m, sintered carbon, steel, or non-recorded steel After carbon =, the yoke has been subjected to surface treatment, and alloys and so on. -Sharp, silver Negative :: The material is not particularly limited, and examples thereof include carbonaceous materials and bell alloys. Examples of carbon materials are hard stones! M2 is selected from compounds of A1 at least 1st group, 3rd group, and ... 2nd group ($ 3, 1S18). ',' 〇 < pa, 1 "The separator is made of an insulating film with light and strong strength. It has a penetrability and has a predetermined mechanical adoption. From the viewpoint of resistance to organic solvents and hydrophobicity, it is not used. Sheets or non-woven fabrics made of olefins such as propylene: holes: σ :: dimensional, or polyethylene, etc. t η ^ m ^ ^ mesh plate aperture /, as long as it is within the scope of general battery use, for example. 01 For the battery range, it can be a low-order system /, solid polymer and other solid electricity = 5 ~ 300. In addition, when the electrolytic solution is described later, the solid electrolyte can also serve the purpose of 13 200532961. In addition, ethanolamine can be used as a separator. In addition, in order to improve the discharge or charge and discharge characteristics, pyridine, triethylphosphite, and dihydrate can be added to the electrolyte. The nonaqueous electrolyte containing bell salt is composed of a nonaqueous electrolyte and Lithium salt. Non-aqueous electrolyte is non-aqueous electrolyte or organic solid electrolyte. Non-aqueous solution can be selected from, for example, N-methyl-2 -pyrrolidine di_, propylene carbonate, electrolyzed ethylene carbonate, Butene carbonate, dimethyl carbonate, diethyl carbonate, -Butyrinol, 1,2-dimethoxyethane, tetrahydrofuran, 2 monomethyltetrazolium:, dimethyl sulfene, 1,3-dioxolane, formamidine, Dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphate triester, trimethoxymethane, dioxolane derivatives, cyclobutadiene, 3-methyl One of aprotic organic solvents, such as dimethyl 2-oxazole dione, propylene carbonate derivative, tetrahydrofuran derivative, diethyl ether and 1,3 propane sultone, or a mixture of two or more solvents. The organic solid electrolyte may be, for example, a polyethylene derivative or a polymer containing polyisopropane derivative or a polymer containing the same, a phosphate polymer, and the like. The lithium salt may be one which is dissolved in the above-mentioned non-aqueous electrolyte.

LlC1〇4, LiBF4, LiPF6, LiCF3S03, LiCF3C02, LiAsF6,

One of LlSbI? 6, UB1Gci1G, LiAlCh, lithium chloroboride, lower aliphatic carboxylic acid clock, lithium tetrabenzyl borate, or a mixture of two or more salts. The shape of the secondary battery according to the present invention can be applied to any of a button shape, a sheet shape, and a eloquence square shape. The use of the lithium secondary battery of the present invention is not limited. For example, a notebook computer, a laptop computer, a pocket processor, a mobile phone, a wireless phone handset, and a mobile phone. Electronic equipment such as CD speakers, 14 200532961 radios, etc .; consumer electronics equipment such as automobiles and electric and semi-gaming equipment. In addition, in a non-aqueous electrolyte secondary battery via a secondary thunder tank, the present invention provides an electronic device including the non-aqueous electrolyte w ... Crying with an electronic device can be related to 戍. σ For example: · Notebook computer, lip word processor, mobile phone, helmet ^ "…, green electric live machine, mobile CD sound changer, radio, game machine, etc. EXAMPLES Hereinafter, the samarium complex oxide and nonaqueous electrolyte secondary battery of the present invention will be described in more detail. Example 1 In a manner such that the U / C0 ratio is uo, an experimental gas oxide drill (average particle size 10, m, angle of repose 45 °, tap density 15_, compounding ratio with a bell compound, and weighed. Mix the raw materials until they reach a homogeneous state. State. The mixed raw materials are charged into the oxidative scourge, and calcined in the air at 0c 11 GO c. After firing, they are crushed and classified. In addition, 'for use as raw materials For the above-mentioned bell-cobalt composite oxide, "SEM photographs of different magnifications are shown in Fig. 1, Fig. 2, and Fig. 3. The average particle diameter of the silk composite oxide obtained was 107 μm, and the residual amount of bell carbonate was 0.05 % By weight, 3.77g / cm3 compression density. Implementing you |? Except for the use of basic cobalt hydroxide with an average particle diameter of 12 艸, a rest angle of 45 degrees, and a tap density of 1.6g / cm3, the other implementation conditions are the same as Example 1 is the same. The average particle diameter of the lithium-cobalt composite oxide obtained was ΐ2.5-5, carbonic acid 15 200532961, the residual amount of lithium was 0.04% by weight, and the pressure density was 3. 78g / cm3. 14 calls, rest angle of 40 °, tapping density, and other test methods All are the same as the examples. The average particle size of the lithium-cobalt composite oxide obtained is 12.8, the residual amount of lithium carbonate is 0.05% by weight, and the pressure density is 3 75 g / cm3. Comparative Example 1 Except, the average particle size was used. 2 叩, the rest of the implementation conditions are the same as in Example 1 except for the test cobalt cobalt hydroxide with a rest angle of 63 degrees and a tap density of 1 · 1-3. The average grain size of the obtained bell diamond composite oxide is @ 12. 8 叫, carbonic acid Residual lithium I 0 · 15% by weight, pressurized density 3. 51 g / cm3. Comparative Example 2 Except for if, the average particle size is 3 μm, the angle of repose is 60 degrees, and the tap density is 1.2 · 3. In addition, the other implementation conditions are the same as the implementation: the average Zhao diameter of the lithium-cobalt composite oxide obtained is 127_, the residual lithium carbonate is $ 0 · 18 by weight, and the compression density is 3.52g / cm3. The measurement bar is stationary A powder tester PT-N type device (manufactured by Hosokawa Micron Co., Ltd.) was used. The sample was passed through a sieve with a mesh size of 25 μm, and dropped through a funnel to a table for measuring the angle of repose ± 't to form a stable The angle of repose was measured at the time of the Yamagata. The particle size analysis method uses a Microtrac particle size distribution meter 932.0_xl〇〇 (Le ed & Nortrup, Inc.) and implemented according to the following conditions. In the sample built in the above-mentioned particle size distribution laboratory 200532961, a person who knows 300 ml of ultrapure water, and then added 10% sodium hexametaphosphate 2ml. Then,夭 丄 ^ Add the sample until the concentration suitable for the particle size distribution meter is the above operation is performed at a return flow rate of 40 ml / sec. After performing a dispersion treatment using an ultrasonic wave at an output power of 40 W for 60 seconds, the average particle size is measured. The pressure-tight test 1 uses a 15 mm diameter mold and presses it with a pressure of 2 tn / cm2 (& / model WPN-10, manufactured by Tomorrow Corporation). Then measure the particle weight and volume 'and calculate the particle density. Weight-cell performance test t (I) Fabrication of a button type non-aqueous electrolyte secondary battery & The lithium-cobalt composite emulsion 91% by weight, graphite powder of Example 3 and Comparative Example " 6% by weight and polyvinylidene fluoride-3% by weight were mixed to form a positive electrode, and the mixture was dispersed in N-methyl-2-pyrrolidine dis to prepare a mixed-chain exciter. Apply the mixed chain coating on the chain box, then ^ after drying, stamping, and punching to a diameter! After the 5_ disc, a positive plate was obtained. Using this positive electrode plate, and using components such as a separator, a negative electrode, a positive electrode, a current collecting plate, a mounting member, an external terminal, and an electrolyte, a clock secondary battery (that is, a non-aqueous electrolyte secondary battery) is manufactured. Among them, the negative electrode system uses a metal clock box, and the electrolytic solution is a mixed solution of ethylene carbonate and diethyl carbonate: 1 mole of LiPF6 in 1 liter. (D) Evaluation of load characteristics: 1. Operate the manufactured button type non-aqueous electrolyte secondary battery at room temperature, and slam the load characteristics. First, charge the positive electrode with a constant current voltage (cccv) of 17 200532961. Apply 5 hours at 0.5C and charge to 4 · 3ν, then discharge at a discharge rate of 0.2C to 2.7V for charge and discharge. The i cycle to the third cycle are the average values of the discharge capacity of each cycle, and this value is regarded as the capacitance. The same operation was performed at 2C, and the discharge capacity was obtained. Based on these two ', the discharge capacity ratio of 2C / 0.2C was calculated. A larger value indicates better load characteristics. (冚) Production of aluminum laminated non-aqueous electrolyte secondary battery 〃 〃The lithium-cobalt composite emulsion of Example 3 and Comparative Example 2 prepared according to the above will be 91% by weight, graphite powder 6% by weight, and polyisocyanate. 3% by weight of ethyl acetate were mixed to form a positive electrode agent, which was dispersed in N-methyl-2-pyrrolidine diisocyanate: to form a mixed-chain exciter, which was coated on the rhenium, and then dried, It was punched and cut into 50 cm X 5 cm to prepare a positive electrode sheet. In addition, MC_5% by weight and Polyvinylidene 154% by weight were mixed to form a negative electrode agent, and the mixture was dispersed in N-methyl-2-o-biolamine to prepare a mixed chain coating. The mixed-chain paint was coated on an aluminum box, cut into 50 cm x 5 cm after drying, a separator was inserted between the negative electrode sheets, and a 25 cm separator was folded on the bottom layer. This was put in an aluminum laminate, vacuum-filled in an electrolytic solution, and then heat-sealed to obtain an aluminum laminate battery. (VI) Evaluation of swelling The obtained aluminum laminated non-aqueous electrolyte secondary battery was maintained for 20 days under a charged state of 60 t and 4.3 V. After 20 days, the aluminum laminate type non-aqueous electrolyte secondary battery was taken out and the expanded state was confirmed. The results are shown in Table i. 18 200532961 Table 1

-—. ^ __ (%) Swelling Example 1 ____80 〇Example 2 .__ 82 〇Example 3 89 〇Comparative Example 6 40 X _ Comparative Example 7 45 X As explained above, by the description of the present invention By using the starting composite oxide as a positive electrode active material, a nonaqueous electrolyte secondary battery capable of suppressing battery expansion and having excellent load characteristics can be obtained. [Schematic description]

FIG. 1 is a SEM photograph of basic cobalt hydroxide used in Example 1 of the present invention. FIG. 2 is a sem photograph of basic cobalt hydroxide used in Example 1 of the present invention.

FIG. 3 is a SEM photograph of basic cobalt hydroxide used in Example 1 of the present invention. 19

Claims (1)

200532961 Scope of patent application: 1 · A bell-start composite oxide, which is a lithium-cobalt composite oxide prepared from a test compound and a bell compound, and is characterized by an average particle diameter of the lithium-cobalt composite oxide The range is from 10 to 15 μm, and the residual amount of the acid-breaking bell is less than or equal to q 1 wt%. 2. · A method for manufacturing a lithium-cobalt composite oxide, characterized in that basic cobalt hydroxide is mixed with a lithium compound and then fired to obtain a lithium-cobalt composite Oxide 'This basic cobalt hydroxide has a repose angle of less than degrees and a tap density of 1 · 3 ~ 1 · 8g / cm3. 3. The method for manufacturing a lithium-cobalt composite oxide according to item 2 of the scope of patent application, wherein the basic cobalt hydroxide is a secondary particle formed by agglomerating primary particles of 0 ~ 3 eggs, and the secondary particles The average particle size is 8 ~ 丨 8 叩. 4. A non-aqueous electrolyte secondary battery. The positive electrode active material contained in the positive electrode is a lithium-cobalt composite of the patent application 圚 月 τ 固 target solid item 丨. 5 · A portable electronic device with features ^ 7, # s ^ # T 1 is an obstacle, and it is a non-aqueous electrolyte secondary battery with item 4 of the patent application scope. Pick up, schema: as next page 20