Method for preparing positive electrode active material

Abstract

新たな正極活物質の製造方法を提供する。【解決手段】ニッケル、コバルトおよびマンガンを有する水溶液と、第1の添加元素を有する水溶液とを混合して、酸溶液を作製し、前記酸溶液と、アルカリ溶液とを反応させて、ニッケル、コバルト、マンガンおよび第1の添加元素を有する複合水酸化物を形成し、複合水酸化物と、リチウム源とを混合し、第1の加熱をして、複合酸化物を形成し、複合酸化物と、第2の添加元素源とを混合し、第2の加熱をする、正極活物質の製造方法であって、第1の添加元素はガリウム、ホウ素、アルミニウム、インジウム、マグネシウムおよびフッ素の中から選ばれる少なくとも一であり、第2の添加元素はカルシウム、ガリウム、ホウ素、アルミニウム、インジウム、マグネシウムおよびフッ素の中から選ばれる少なくとも一である、正極活物質の作製方法である。

Description

Technical Field

[0001] One aspect of the present invention relates to an article, a method, or a manufacturing method. One aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. One aspect of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, or an electronic device, or a manufacturing method thereof. In particular, one aspect of the present invention relates to a positive electrode active material for a lithium-ion secondary battery, and a manufacturing method thereof.

Background Art

[0002] In recent years, lithium-ion secondary batteries with high output and high capacity have rapidly expanded in demand and have become indispensable in modern society as an energy source that can be repeatedly utilized. Among them, lithium-ion secondary batteries for portable electronic devices are required to have a large discharge capacity per unit weight and excellent charge / discharge characteristics. In order to meet these requirements, improvements to the positive electrode active materials of lithium-ion secondary batteries have been actively carried out. For example, Patent Document 1 discloses a positive electrode active material with excellent charge / discharge characteristics.

[0003]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Lithium-ion secondary batteries and the positive electrode active materials used therein have capacity, cycle characteristics, Improvements are desired in various aspects, including charge / discharge characteristics, reliability, safety, and cost.

[0006] In view of the above, one aspect of the present invention provides a positive electrode active material that exhibits less degradation and a method for producing the same. One of the challenges is to provide a low-cost positive electrode active material and One objective is to provide a method for manufacturing. Alternatively, one aspect of the present invention relates to a transition metal as One of the objectives is to provide a positive electrode active material with a high nickel content and a method for producing the same. Alternatively, one aspect of the present invention provides a positive electrode active material with good charge-discharge characteristics and a method for producing the same. One of the challenges is to provide a highly safe secondary battery and its operation. One objective of this invention is to provide a manufacturing method. Alternatively, one aspect of this invention relates to a novel positive electrode active material. One of the objectives is to provide a method for producing [the product].

[0007] Furthermore, the description of the above issues does not preclude the existence of other issues. From the description of the claims, it is possible to extract problems other than those described above. And the first of the present invention The embodiment does not need to solve all of the above problems, but at least one of them needs to be solved. It is. [Means for solving the problem]

[0008] To solve the above problems, in one aspect of the present invention, a positive electrode active material having an additive element is prepared. This was decided upon. The additive elements were added when preparing the composite hydroxide that serves as a precursor to the positive electrode active material. It is also possible to add it when mixing the precursor and the lithium source. Furthermore, lithium and transition gold A composite oxide containing the group may be prepared, and then the additive elements may be added. Additive elements may be added at this stage.

[0009] One aspect of the present invention relates to an aqueous solution having nickel, cobalt, and manganese, and an alkaline solution By reacting with, a composite hydroxide having nickel, cobalt and manganese is formed, The process involves mixing a hydroxide, a lithium source, and a first additive element source, and then heating the mixture to produce a positive electrode active material. A manufacturing method, wherein the first additive element is gallium, boron, aluminum, indium, magnesium A method for producing a positive electrode active material that is at least one selected from nesium or fluorine. ru.

[0010] In the above, the first additive element is gallium, and the first additive element source is gallium hydroxide. Preferably, it is gallium oxyhydroxide or an organic salt of gallium.

[0011] Another aspect of the present invention relates to an aqueous solution having nickel, cobalt, and manganese, and By reacting with a potassium solution, a complex hydroxide containing nickel, cobalt, and manganese is formed. The composite hydroxide is then mixed with a lithium source, and the mixture is heated for the first time to form the composite oxide. A method for producing a positive electrode active material, comprising mixing a composite oxide with a first additive element source and performing a second heating. The law stipulates that the first additive element is calcium, gallium, boron, aluminum, indigo Preparation of a positive electrode active material, which is at least one selected from um, magnesium, or fluorine. It is a method.

[0012] In the above, it is preferable that the second heating is performed at a temperature above 750°C and below 850°C.

[0013] Furthermore, in the above, the first additive element is gallium, and the compound having the first additive element is It is preferable that it be gallium hydroxide, gallium oxyhydroxide, or an organic salt of gallium. It's nice.

[0014] Another aspect of the present invention relates to an aqueous solution having nickel, cobalt, and manganese, and the first An acid solution is prepared by mixing an aqueous solution containing the additive elements, and the acid solution and the alkaline solution are mixed. Reacting to form a composite hydroxide having nickel, cobalt, manganese, and a first additive element. Form a composite hydroxide and a lithium source, and perform a first heating to form the composite oxide. The composite oxide is then mixed with a second source of additive elements, and a second heating process is performed to produce a positive electrode active material. A manufacturing method wherein the first additive element is gallium, boron, aluminum, indium, magnesium At least one selected from nesium or fluorine, and the second additive element is calcium From among aluminum, gallium, boron, aluminum, indium, magnesium, or fluorine This is a method for producing a positive electrode active material that is selected as at least one of the desired materials.

[0015] In the above, it is preferable that the second heating is performed at a temperature above 750°C and below 850°C.

[0016] Furthermore, in the above, the first additive element is gallium, and the source of the first additive element is gallium hydroxide. It is gallium, gallium oxyhydroxide, or an organic acid salt of gallium, and the second additive element is gallium. The primary element is calcium, and the second additive element source is calcium carbonate or calcium fluoride. It is preferable.

[0017] Another aspect of the present invention is a secondary battery having a positive electrode active material prepared by the method described above.

[0018] Another aspect of the present invention is a secondary battery having a positive electrode active material prepared by the above method, and A vehicle having at least one of a brake, a control circuit, and a taillight. [Effects of the Invention]

[0019] According to one aspect of the present invention, it is possible to provide a positive electrode active material that exhibits less degradation and a method for producing the same. It is possible. Alternatively, according to one aspect of the present invention, a low-cost positive electrode active material and a method for producing the same are proposed. It can be provided. Alternatively, according to one aspect of the present invention, the proportion of nickel as a transition metal is This invention can provide a high-performance positive electrode active material and a method for producing the same. Alternatively, in one aspect of the present invention... This makes it possible to provide a positive electrode active material with better charge / discharge characteristics and a method for producing the same. According to one aspect of the present invention, it is possible to provide a highly safe secondary battery and a method for manufacturing the same. Alternatively, one aspect of the present invention can provide a method for producing a novel positive electrode active material. .

[0020] Furthermore, the description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. Furthermore, other effects are... This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings Furthermore, it is possible to extract other effects from the descriptions in the claims and other documents. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 2] Figure 2 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 3] Figure 3 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 4] Figure 4 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 5] Figure 5 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 6] Figure 6 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 7] Figure 7 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 8] Figure 8 is a flowchart illustrating the method for preparing the positive electrode active material. [Figure 9] Figure 9 illustrates the coprecipitation synthesis apparatus. [Figure 10] Figure 10 is a diagram illustrating the coprecipitation synthesis apparatus. [Figure 11] Figure 11 is a diagram illustrating the model used in the calculations. [Figure 12] Figure 12 is a graph showing the calculation results. [Figure 13] Figures 13(A) through 13(D) illustrate the model used in the calculations. [Figure 14] Figures 14(A) and 14(B) illustrate the calculation results. [Figure 15] Figure 15(A) is an exploded perspective view of a coin-type rechargeable battery, Figure 15(B) is a perspective view of a coin-type rechargeable battery, and Figure 15(C) is a cross-sectional perspective view thereof. [Figure 16] Figures 16(A) and 16(B) show examples of cylindrical secondary batteries, Figure 16(C) shows examples of multiple cylindrical secondary batteries, and Figure 16(D) shows examples of energy storage systems with multiple cylindrical secondary batteries. [Figure 17] Figures 17(A) and 17(B) illustrate examples of secondary batteries, while Figure 17(C) shows the inside of a secondary battery. [Figure 18] Figures 18(A) through 18(C) illustrate examples of secondary batteries. [Figure 19] Figures 19(A) and 19(B) show the external appearance of a secondary battery. [Figure 20] Figures 20(A) to 20(C) illustrate the method for manufacturing a secondary battery. [Figure 21] Figures 21(A) to 21(C) show examples of battery pack configurations. [Figure 22] Figures 22(A) and 22(B) illustrate examples of secondary batteries. [Figure 23] Figures 23(A) through 23(C) illustrate examples of secondary batteries. [Figure 24] Figures 24(A) and 24(B) illustrate examples of secondary batteries. [Figure 25] Figure 25(A) is a perspective view of the battery pack, Figure 25(B) is a block diagram of the battery pack, and Figure 25(C) is a block diagram of a vehicle having the battery pack and motor. [Figure 26] Figures 26(A) to 26(D) illustrate an example of a transport vehicle. [Figure 27] Figures 27(A) and 27(B) illustrate the energy storage device. [Figure 28] Figure 28(A) shows an electric bicycle, Figure 28(B) shows a secondary battery for an electric bicycle, and Figure 28(C) illustrates an electric motorcycle. [Figure 29] Figures 29(A) to 29(D) illustrate an example of an electronic device. [Figure 30] Figure 30(A) shows an example of a wearable device, Figure 30(B) is a perspective view of a wristwatch-type device, Figure 30(C) is a side view of a wristwatch-type device, and Figure 30(D) is a diagram illustrating an example of wireless earphones. [Figure 31] Figures 31(A) and 31(B) are SEM images of the positive electrode active material. [Figure 32] Figures 32(A) and 32(B) are SEM images of the positive electrode active material. [Figure 33] Figure 33(A) is a graph of charge-discharge cycles and discharge capacity, and Figure 33(B) is a graph of charge-discharge cycles and discharge capacity retention rate. [Figure 34] Figure 34(A) is a graph of charge-discharge cycles and discharge capacity, and Figure 34(B) is a graph of charge-discharge cycles and discharge capacity retention rate. [Modes for carrying out the invention]

[0022] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is... Not limited to the following description, the form and details can be modified in various ways, as any person skilled in the art would know. This is easily understood. Furthermore, the present invention shall be interpreted as being limited to the contents of the embodiments described below. It's not something that can be done.

[0023] A secondary battery has, for example, a positive electrode and a negative electrode. The positive electrode is made up of a positive electrode active material. The positive electrode active material is, for example, a substance that performs a reaction that contributes to the charge and discharge capacity. The substance may include, in part, substances that do not contribute to the charge and discharge capacity.

[0024] In this specification, the positive electrode active material of one aspect of the present invention is a positive electrode material, or a positive electrode active material for a secondary battery. It may be expressed as an electrode material, a composite oxide, etc. Also, in this specification, etc., one aspect of the present invention The positive electrode active material preferably contains a compound. Furthermore, in this specification, etc., the present invention In one embodiment, the positive electrode active material preferably has a composition. Furthermore, in this specification, etc., this In one embodiment, the positive electrode active material preferably has a composite structure.

[0025] In this specification, "crack" is not limited to those occurring during the manufacturing process of the positive electrode active material, but also refers to subsequent cracks. This includes substances produced by pressurization, charging, and discharging.

[0026] In this specification, the surface layer of particles such as active material refers, for example, to a distance of 50 degrees from the surface toward the interior. Within nm, more preferably within 35 nm, even more preferably within 20 nm, most preferably This is a region within 10 nm. Surfaces created by cracks (which can also be called fissures) are also considered surfaces. Yes, you can say that. Also, the region deeper than the surface is called the interior. At this time, particles such as active material are one Let's assume that we are not distinguishing between first-order particles and second-order particles.

[0027] In this specification, the term "particle" is not limited to spherical (circular cross-section), but also refers to individual The cross-sectional shape of the particles can be elliptical, rectangular, trapezoidal, triangular, square with rounded corners, or asymmetrical. Examples include, and furthermore, individual particles may have an amorphous shape.

[0028] In this specification, a value in the vicinity of a given numerical value A is defined as a value between 0.9 × A and 1.1 × A. Let's leave it at that.

[0029] (Embodiment 1) In this embodiment, Figures 1 to 8 show the preparation of a positive electrode active material 100 according to one aspect of the present invention. Let me explain an example of the method.

[0030] The flowcharts shown in Figures 1 through 8 illustrate the order of elements connected by lines. This does not indicate the timing of elements that are not directly connected by lines. For example, in Figure 1 Steps S11 and S21 are shown at the same height in the diagram, but they do not necessarily occur simultaneously. It is not necessary to do so.

[0031] [Manufacturing Method 1] First, using Figures 1 and 2, we prepared a composite hydroxide 98, which will serve as a precursor to the positive electrode active material 100. This section explains how to add element X1 during the process.

[0032] <Step S11> In step S11 of Figures 1 and 2, a transition metal M source is first prepared.

[0033] As the transition metal M, for example, at least one of nickel, cobalt, and manganese is used. This is possible. For example, if only nickel is used as the transition metal M, then cobalt and When using two types of manganese, when using two types of nickel and cobalt, or nickel In some cases, three types of minerals are used: ammonium compounds, cobalt, and manganese.

[0034] When at least one of nickel, cobalt, and manganese is used, a layered rock salt type crystal structure It is preferable to use a mixing ratio of nickel, cobalt, and manganese within a range that is possible.

[0035] In particular, if the positive electrode active material 100 contains a large amount of nickel as the transition metal M, then it will contain a large amount of cobalt. In some cases, the raw materials may be cheaper compared to other methods, and the charge / discharge capacity per unit weight may increase. A good combination is preferable. For example, it is preferable that nickel among the transition metal M exceeds 25 atomic percent. More preferably 60 atomic percent or more, and even more preferably 80 atomic percent or more. However, If the proportion of kel is too high, the chemical stability and heat resistance may decrease. Of the transition metal M, nickel is preferably at a concentration of 95 atomic percent or less.

[0036] When cobalt is present as the transition metal M, the average discharge voltage is high, and the cobalt is of the layered rock salt type. This contributes to the stabilization of the structure, making it preferable to have a highly reliable secondary battery. However, Cobalt's price is higher and more unstable than nickel and manganese, therefore cobalt If the proportion is too high, it could increase the cost of manufacturing secondary batteries. For example, among the transition metals M, cobalt is preferably present in an amount of 2.5 atomic percent or more and 34 atomic percent or less. stomach.

[0037] Note that the transition metal M does not necessarily have to include cobalt.

[0038] Having manganese as the transition metal M is preferable because it improves heat resistance and chemical stability. However, if the proportion of manganese is too high, the discharge voltage and discharge capacity tend to decrease. Yes, for example, among the transition metals M, manganese is between 2.5 atomic percent and 34 atomic percent. It is preferable that this be the case.

[0039] Note that the transition metal M does not necessarily have to include manganese.

[0040] The transition metal M source is prepared as an aqueous solution containing the transition metal M. The nickel source is nickel. An aqueous solution of the salt can be used. Examples of nickel salts include nickel sulfate and nickel chloride. Nickel, nickel nitrate, or hydrates thereof can be used. Nickel acetate can also be used. Nickel organic salts, including those listed above, or their hydrates can also be used. Using an aqueous solution of nickel alkoxide or an organic nickel complex as a nickel source is possible. Yes, it is possible. In this specification, organic acid salts refer to acetic acid, citric acid, oxalic acid, formic acid, and buttery acid. This refers to compounds of organic acids (such as acids) and metals.

[0041] Similarly, an aqueous solution of a cobalt salt can be used as a cobalt source. For example, cobalt sulfate, cobalt chloride, cobalt nitrate, or hydrates thereof can be used. It is possible to have cobalt organic salts, including cobalt acetate, or these Hydrates of can also be used. In addition, cobalt alkoxides and organic cobalt can be used as cobalt sources. An aqueous solution of the Ruth complex can be used.

[0042] Similarly, an aqueous solution of manganese salt can be used as a source of manganese. For example, manganese sulfate, manganese chloride, manganese nitrate, or hydrates thereof can be used. It can be present. Also, manganese acetate and other organic salts of manganese, or these Hydrates can also be used as manganese sources, or manganese alkoxides or An aqueous solution of the manganese complex can be used.

[0043] In this embodiment, nickel sulfate, cobalt sulfate, and manganese sulfate are used as the transition metal M source. Prepare an aqueous solution by dissolving n in pure water. At this time, nickel, cobalt and The atomic ratio of manganese is Ni:Co:Mn = 8:1:1 or close to this. It is acidic.

[0044] <Step S12> Furthermore, in step S12 of Figures 1 and 2, a source of additive element X1 is prepared.

[0045] Examples of additive elements X1 include gallium, boron, aluminum, indium, and fluorine. Magnesium, titanium, yttrium, zirconium, niobium, lanthanum, and hafni At least one selected from among the elements can be used. For example, as additive element X1 When using only gallium, when using two types of gallium and aluminum, gallium and In some cases, three elements are used, such as boron and aluminum.

[0046] The source of additive element X1 is also prepared as an aqueous solution containing additive element X1. As for the gallium source, for example, For example, an aqueous solution of gallium hydroxide or a gallium salt can be used. Examples include gallium sulfate, gallium acetate, or gallium nitrate.

[0047] As a boron source, for example, an aqueous solution of boric acid or a borate salt can be used.

[0048] As an aluminum source, for example, an aqueous solution of aluminum hydroxide or an aluminum salt. It can be used. Examples of aluminum salts include aluminum sulfate, aluminum acetate, and Examples include aluminum nitrate.

[0049] As an indium source, for example, an aqueous solution of indium hydroxide or an indium salt can be used. This is possible. Indium salts include indium sulfate, indium acetate, or indium nitrate. Examples include Um, etc.

[0050] Examples of fluorine sources include gallium fluoride, boron fluoride, aluminum fluoride, or An aqueous solution of magnesium fluoride can be used.

[0051] Magnesium sources include, for example, magnesium hydroxide, magnesium carbonate, or fluoride. An aqueous solution of magnesium can be used.

[0052] In this embodiment, gallium is used as the additive element X1, and gallium sulfate is used as the additive element X1 source. Prepare an aqueous solution by dissolving um in pure water.

[0053] <Step S13> Alternatively, as shown in step S13 of Figure 2, a chelating agent may be prepared. For example, glycine, oxine, 1-nitroso-2-naphthol, 2-mercaptobene Examples include zothiazole or EDTA (ethylenediaminetetraacetic acid). N, oxin, 1-nitroso-2-naphthol, 2-mercaptobenzothiazole, also Multiple types of EDTA may be used. Dissolve at least one of these in pure water. It is dissolved and used as a chelate aqueous solution. A chelating agent is a complexing agent that forms a chelate compound. , which is preferable to general complexing agents. Of course, a complexing agent may be used instead of a chelating agent, and the complexing agent and Ammonia water can be used.

[0054] By using a chelate aqueous solution, the unwanted formation of crystal nuclei can be suppressed, and crystal growth can be promoted. This is preferable. Since the generation of unwanted nuclei is suppressed, the generation of fine particles is suppressed, resulting in a good particle size distribution. A good complex hydroxide can be obtained. Furthermore, by using a chelate aqueous solution, acid-base reactions can be performed. This allows the reaction to be delayed, and by allowing the reaction to proceed gradually, near-spherical secondary particles can be obtained. Glycine maintains a constant pH value between 9.0 and 10.0, and around that range. It has an effect, and by using a glycine aqueous solution as the chelate aqueous solution, the above composite hydroxide 9 It is preferable that the pH of the reaction vessel when obtaining 8 becomes easier to control. Furthermore, the glycine aqueous solution The concentration is preferably 0.05 mol / L or more and 0.5 mol / L or less, and 0.1 mol / L A concentration of 0.2 mol / L or less is more preferable.

[0055] <Step S14> Next, in step S14 of Figure 1, the transition metal M source and the additive element X1 source are mixed to create an acid solution. Prepare the mixture. A chelating agent may be further mixed in, as shown in Figure 2.

[0056] If the ratio of the added element X1 to the transition metal M is too low, the positive electrode active material 100 will be inferior. The effect of suppressing oxidation or improving charge / discharge characteristics is not sufficiently obtained. If the proportion of element X1 is too high, the charge / discharge capacity of the positive electrode active material 100 will decrease, and the cost will increase. This can lead to disadvantages. For example, all transition metals M and additive elements X It is preferable to mix the elements such that the sum of the added elements X1 is 10 atomic percent or less relative to the sum of the elements 1. Furthermore, it is more preferable to mix them so that the total amount is between 1 atomic% and 4 atomic%. When the ratio of children is (M+X1):X1=1:A, it is preferable that A≦0.1, and 0.01 It is more preferable that ≤A ≤ 0.04.

[0057] In this embodiment, the atomic ratio of nickel, cobalt, manganese, and gallium is Ni:C When o:Mn:Ga = 80:10:(10-x):x, mix so that 1 ≤ x ≤ 4. Let's do it this way.

[0058] <Step S21> Next, in step S21 of Figures 1 and 2, an alkaline solution is prepared. For example, sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia An aqueous solution containing A can be used. An aqueous solution obtained by dissolving these using pure water can be used. It is possible to use sodium hydroxide, potassium hydroxide, lithium hydroxide, or an An aqueous solution prepared by dissolving several selected species of Monia in pure water may also be used.

[0059] The transition metal M source, the additive element X1 source, and the pure water preferred for use in the alkaline solution are, in proportion to Water with a resistivity of 1 MΩ·cm or more, more preferably water with a resistivity of 10 MΩ·cm or more, further Preferably, the water has a resistivity of 15 MΩ·cm or more. Water that satisfies this resistivity has high purity. It contains very few impurities.

[0060] <Step S22> Furthermore, as shown in step S22 of Figure 2, it is preferable to prepare water in the reaction vessel. This may be pure water, but it is more preferable to be an aqueous solution of a chelating agent. The water can be called a chelate solution, a reaction vessel filler, or a adjusting solution. When using an aqueous solution, the description in step S13 can be taken into consideration.

[0061] <Step S31> Next, in step S31 of Figures 1 and 2, the acid solution and the alkaline solution are mixed and reacted. This reaction can be described as a coprecipitation reaction, a neutralization reaction, or an acid-base reaction.

[0062] During the coprecipitation reaction in step S31, the pH of the reaction system should be between 9.0 and 11.0, preferably p It is preferable to set H to be between 9.8 and 10.3.

[0063] For example, when an alkaline solution is placed in a reaction vessel and an acidic solution is added dropwise to the reaction vessel, the aqueous solution in the reaction vessel It is best to maintain the pH within the above conditions. Also, keep the acid solution in the reaction vessel and then dissolve the alkali solution. The same applies when adding liquid dropwise. The dropping rate of the acid or alkaline solution depends on the reaction vessel's solvent. If the liquid volume is between 200 mL and 350 mL, the flow rate should be between 0.01 mL / min and 1 mL / min, if desired. Alternatively, a flow rate of 0.1 mL / min or more and 0.8 mL / min or less is preferable as it makes it easier to control the pH conditions. The reaction vessel includes reaction vessels, etc.

[0064] It is advisable to stir the aqueous solution in the reaction vessel using a stirring device. The stirring device may be a stirrer or It has stirring blades, etc. Two to six stirring blades can be provided; for example, four stirring blades. In this case, it is best to arrange them in a cross shape when viewed from above. The rotation speed of the stirring means should be 800 rpm. It is best to keep the speed below 1200 rpm.

[0065] It is preferable to adjust the temperature of the reaction vessel to be between 50°C and 90°C. The dropwise addition of the liquid or acid solution should begin after the temperature has reached the target temperature.

[0066] Furthermore, it is preferable to maintain an inert atmosphere inside the reaction vessel. In this case, the inert atmosphere should be nitrogen or aluminum GON can be used. When using a nitrogen atmosphere, nitrogen gas can be supplied at a rate of 0.5 L / min or more, up to 2 L / min. It is best to introduce it with a flow rate of less than one minute.

[0067] It is also advisable to place a reflux condenser in the reaction vessel. The reflux condenser allows nitrogen gas to be released from the reaction vessel. The water can be released and returned to the reaction vessel.

[0068] The above coprecipitation reaction precipitates the complex hydroxide 98 having the transition metal M and additive element X1. do.

[0069] <Step S32> To recover the complex hydroxide 98, filtration is performed as shown in step S32 of Figure 2. This is preferable. Suction filtration is preferred for filtration. During filtration, the reaction product that settles in the reaction vessel is drained with pure water. After washing, add a low-boiling point organic solvent (e.g., acetone) and then perform the above filtration. And that is preferable.

[0070] <Step S33> As shown in step S33 of Figure 2, the filtered composite hydroxide 98 should be dried. For example, it is dried under vacuum at a temperature between 60°C and 90°C for 0.5 hours to 3 hours. The composite hydroxide 98 can be obtained in this manner.

[0071] In this way, a composite hydroxide 98 having a transition metal M and an additive element X1 can be obtained. Yes, it is possible. In this specification, composite hydroxide 98 refers to a hydroxide of multiple metals. Therefore, the composite hydroxide 98 can be considered a precursor of the positive electrode active material 100.

[0072] The composite hydroxide 98 is obtained as secondary particles formed by the aggregation of primary particles. Primary particles are those observed, for example, at 5000x magnification using a scanning electron microscope (SEM). In other words, a primary particle is the smallest unit of particle (clump) that does not have grain boundaries within it. This refers to the smallest unit of particle enclosed by a boundary. A secondary particle is a particle of the same type as the primary particle. Particles that aggregate by sharing a portion of their boundary (such as the outer circumference of a primary particle) and do not easily separate (with others) This refers to independent particles. In other words, secondary particles may have grain boundaries.

[0073] <Step S41> Next, in step S41 of Figures 1 and 2, a lithium source is prepared. For example, lithium hydroxide, lithium carbonate, or lithium nitrate can be used. In particular, lithium compounds with low melting points, such as lithium hydroxide (melting point 462°C), are used. It is preferable to have it. A positive electrode active material with a high nickel content is preferable to lithium cobalt oxide, etc. Because cation mixing is likely to occur, heating in step S54 and other steps must be performed at a low temperature. Therefore, it is preferable to use a material with a low melting point.

[0074] The lithium source described above preferably uses a high-purity material. Specifically, the purity of the material is Therefore, 4N (99.99%) or higher, preferably 4N5 (99.995%) or higher, even more preferably The purity is 5N (99.999%) or higher. By using high-purity materials, secondary batteries Battery characteristics can be improved.

[0075] <Step S51> Next, in step S51 of Figures 1 and 2, the composite hydroxide 98 and the lithium source are mixed. Mixing can be done dry or wet. Mixing can be done using, for example, a ball mill or a bead mill. The following can be used. When using a ball mill, for example, zirconia can be used as the media. It is preferable to use balls. Also, when using a ball mill or bead mill, To suppress contamination from media or materials, the peripheral speed is set to 100 mm / second. It is preferable to have a mixing rate of 2000 mm / second or less. The cobalt compound and lithium are mixed simultaneously. Um compounds are sometimes pulverized.

[0076] <Steps S52 to S55> Next, the mixture of composite hydroxide 98 and lithium source is heated. Heating is performed in step S5 of Figure 1. As shown in 4, it may be done once, but as shown in steps S52 and S54 of Figure 2 It is preferable to perform this twice. Although not shown in the diagram, heating may be done three or more times.

[0077] To distinguish it from other heating processes, in Figure 2, step S52 is referred to as the first heating, and step S54 This is sometimes referred to as the second heating stage.

[0078] For these heating processes, electric furnaces or rotary kilns are used as firing equipment. This is possible. Containers such as crucibles, pods, and setters used during heating release impurities. It is preferable that the material be a pile material. For example, a crucible made of aluminum oxide with a purity of 99.9% is used. It's good to have. For mass production, for example, mullite cordierite (Al2O3·SiO2 It is best to use a pod containing MgO. Also, heating these containers with the lids on is recommended. preferable.

[0079] When heating in step S52 as shown in Figure 2, the heating temperature is between 400°C and 700°C. This is preferable. Furthermore, the heating time in step S52 is preferably between 1 hour and 10 hours. The heating in step S52 is performed at a lower temperature than the heating in step S54, and / or It is preferable to perform this in a short amount of time.

[0080] The heating atmosphere is an oxygen-containing atmosphere, or so-called dry air with low water content and oxygen. The atmosphere (for example, a dew point of -50°C or lower, more preferably a dew point of -80°C or lower) preferable.

[0081] For example, when heating at 850°C for 2 hours, the heating rate should be between 150°C / hour and 250°C / hour. The following is recommended. Furthermore, the flow rate of dry air that can create a dry atmosphere should be between 8 L / min and 15 L / min. It is preferable that the cooling time be less than / minute. It is preferable that the cooling time be between 1 hour and 50 hours, and the cooling rate can be calculated from the cooling time, etc. can.

[0082] The heating in step S52 releases the composite hydroxide 98 and the gaseous components in the lithium source. It is expected that the amount of impurities will decrease by using the composite hydroxide 98 and lithium source. It is possible to obtain complex oxides that do not exist.

[0083] Furthermore, as shown in steps S53 and S55 of Figure 2, a crushing step is performed after heating. It is preferable to do so. The crushing can be done, for example, in a mortar and pestle. Furthermore, using a sieve Classification is also possible. By having a crushing process, the particle size and / or shape of the positive electrode active material 100 can be determined. This can be made more uniform.

[0084] The heating in step S54 shown in Figures 1 and 2 is performed at a temperature greater than 700°C and less than or equal to 1050°C. It is preferable to carry it out at a temperature of 800°C or higher and 1000°C or lower, and more preferably at 800°C. A temperature of 950°C or higher is more preferable. The positive electrode active material 100 is produced after this heat treatment. In this process, it is important to heat the ingredients to a temperature at which each ingredient melts.

[0085] The heating time can be, for example, between 1 hour and 100 hours, or between 2 hours and 20 hours. It is preferable to do so.

[0086] The heating atmosphere, heating rate, cooling time, etc., can be determined by referring to the description in step S52.

[0087] Furthermore, when collecting the ingredients after heating, if they are moved from the crucible to a mortar and pestle before collection, It is preferable because no impurities are mixed into the materials. Furthermore, the mortar itself is also designed to release impurities. The pile material is preferable, specifically an acid with a purity of 90% or higher, preferably 99% or higher. It is best to use an aluminum mortar and pestle.

[0088] The positive electrode active material 100 can be produced through the above process.

[0089] The positive electrode active material 100 is preferred because it contains few impurities. However, starting materials such as transition metal M source When sulfides are used in the material, sulfur may be detected in the positive electrode active material 100. D-MS (glow discharge mass spectrometry), ICP-MS (inductively coupled plasma mass spectrometry), etc. By using this method, elemental analysis of the entire particle of the positive electrode active material 100 can be performed, and the sulfur concentration can be measured. ru.

[0090] [Preparation Method 2] Next, using Figures 3 and 4, when mixing composite hydroxide 98 with a lithium source, add elements This section explains how to add X2. It mainly describes the process that differs from Figures 1 and 2. For other steps, please refer to the descriptions in Figures 1 and 2.

[0091] <Steps S11 to S41> Except for not using additive element X1, the steps are the same as steps S11 to S31 in Figures 1 and 2. In this process, a composite hydroxide 98 having a transition metal M is obtained. Also, the steps in Figures 1 and 2. Prepare a lithium source, similar to S41.

[0092] <Step S42> Next, in step S42 of Figures 3 and 4, a source of additive element X2 is prepared.

[0093] Examples of additive elements X2 include gallium, boron, aluminum, indium, and fluorine. Magnesium, titanium, yttrium, zirconium, niobium, lanthanum, and hafni At least one selected from among Um can be used. For example, as additive element X2 When using only gallium, when using two types of gallium and aluminum, gallium and In some cases, three elements are used, such as boron and aluminum. The two sources of added elements are not necessarily aqueous solutions. It doesn't have to be that way.

[0094] Gallium sources include, for example, gallium oxide, gallium oxyhydroxide, and gallium hydroxide. Alternatively, gallium salts can be used. Gallium sources include gallium sulfate and gallium acetate. Examples include gallium nitrate, etc. Gallium alkoxide may also be used.

[0095] As a boron source, for example, boric acid or borate salts can be used.

[0096] Aluminum sources include, for example, aluminum oxide, aluminum hydroxide, or aluminum Aluminum salts can be used. Examples of aluminum salts include aluminum sulfate and aluminum acetate. Examples include aluminum or aluminum nitrate. Aluminum alkoxides may also be used. stomach.

[0097] Indium sources include, for example, indium oxide, indium sulfate, indium acetate, and Indium nitrate can be used. Indium alkoxide may also be used.

[0098] Examples of fluorine sources include gallium fluoride, boron fluoride, aluminum fluoride, and fluorine. Magnesium oxide can be used.

[0099] Magnesium sources include, for example, magnesium oxide, magnesium hydroxide, and magnesium carbonate. Cium and magnesium fluoride can be used. Using magnesium alkoxide That's good too.

[0100] In this embodiment, gallium is used as the additive element X2, and oxyhydrogen water is used as the additive element X2 source. We will prepare gallium oxide.

[0101] <Steps S51 through S55> Subsequently, heating and other processes are carried out in the same manner as in steps S51 to S55 in Figures 1 and 2, and correct A highly active material 100 can be produced.

[0102] [Method 3 of preparation] Next, using Figures 5 and 6, a composite oxide 99 having lithium and a transition metal M was prepared. Next, we will explain the method for adding additive element X3. This mainly involves steps that differ from those shown in Figures 1 to 4. This will be explained, and other steps can be considered in relation to Figures 1 to 4.

[0103] <Steps S11 through Step S55> In a process similar to steps S11 to S33 in Figures 3 and 4, a transition metal M is obtained. A composite hydroxide 98 is obtained. Then, steps S41 to S54 in Figures 1 and 2. In a similar process, the composite hydroxide 98 and lithium source are subjected to heating, etc. Step S in Figure 2. As shown in 55, it is more preferable to crush the material after heating.

[0104] As shown in Figures 5 and 6, the material produced through the above process is a composite. Let's assume it's an oxide 99.

[0105] <Step S61> Next, in step S61 of Figures 5 and 6, a source of additive element X3 is prepared.

[0106] Examples of additive element X3 include calcium, gallium, boron, aluminum, and indigo. Umium, fluorine, magnesium, titanium, yttrium, zirconium, niobium, lanthanum At least one selected from and hafnium can be used. For example, the additive When using only calcium as element X3, when using only gallium, aluminum When using only calcium and gallium, when using two types of calcium and aluminum When using two types of aluminum, or when using three types of aluminum, such as calcium, gallium, and aluminum, etc. be.

[0107] The additive element X3 source uses a material that does not contain water, or has less water than the additive element X1 source. This is preferable. This is to avoid the reaction between the composite oxide 99 and water.

[0108] For example, calcium sources include calcium oxide, calcium hydroxide, or calcium salts. These can be used. Examples of calcium salts include calcium carbonate and calcium fluoride. It can be done.

[0109] For example, titanium oxide or titanium salts can be used as titanium sources. Examples include titanium fluoride, titanium sulfate, titanium acetate, or titanium nitrate. A alkoxide may also be used.

[0110] For example, zirconium oxide or zirconium salts can be used as zirconium sources. This can be done. Examples of zirconium salts include zirconium fluoride, zirconium sulfate, and vinegar. Examples include zirconium acid or zirconium nitrate. Zirconium alkoxide is used. It's okay to be there.

[0111] Gallium source, boron source, aluminum source, indium source, fluorine source, and magnesium source For this, the same material as that used for additive element X2 can be used.

[0112] <Step S71> Next, in step S71 of Figures 5 and 6, the composite oxide 99 and the additive element X3 source are mixed. The mixing can be carried out in the same manner as in step S51.

[0113] <Step S72> Next, as step S72 in Figures 5 and 6, a mixture of composite oxide 99 and additive element X3 is prepared. Heat it up.

[0114] The heating in step S72 is preferably carried out at a temperature of 700°C or higher and less than 1050°C. It is more preferable to perform the heating at a temperature between 50°C and 850°C. The heating time is, for example, 1 hour or more. Step S The heating in step 72 is carried out at a lower temperature and / or for a shorter heating time than the heating in step S54. It is preferable to do so.

[0115] Other conditions such as heating atmosphere, heating rate, and cooling time should be considered in reference to the description in step S54. It is possible.

[0116] <Step S73> As shown in step S73 of Figure 6, it is preferable to have a crushing step after heating. This can be done in the same manner as in steps S53 and S55.

[0117] The positive electrode active material 100 can be produced through the above process.

[0118] After preparing the composite oxide 99 as shown in Figures 5 and 6, the additive element X3 source is mixed in. By heating them together, the depth-direction concentration profile of the elements in the positive electrode active material 100 is altered. In some cases, this can be achieved. For example, the addition of material to the surface layer compared to the interior of the positive electrode active material 100. The concentration of element X3 can be increased. Therefore, the effect of the added element contributes to the stabilization of the surface layer. It can enhance the results.

[0119] [Manufacturing Method 4] Figures 1 to 6 illustrate a method for adding additive elements in a single step, but one aspect of the present invention is... The process is not limited to this, and the steps in Figures 1 to 6 can be combined as appropriate. Using Figure 7 This section explains two methods for adding additive elements, and one method for adding additive elements in three stages, as shown in Figure 8. I will reveal it.

[0120] In the manufacturing method shown in Figure 7, first, the same steps as in steps S11 to S33 in Figure 1 are performed. A composite hydroxide 98 having the transfer metal M and the additive element X1 is obtained. Next, step S41 in Figure 5 In the same process as in step S73, the additive element X3 source is mixed and heated to form the positive electrode active material 10 Get 0.

[0121] In the manufacturing method shown in Figure 8, first, the same steps as in steps S11 to S33 in Figure 2 are performed. A composite hydroxide 98 having the transfer metal M and the additive element X1 is obtained. Next, step S41 in Figure 4 The process is the same as in step S55, and then the additive element X2 source is added, followed by the transition metal M and additive element X1 And a composite oxide 99 having an additive element X2 source is obtained. Furthermore, steps S61 to in Figure 6 The positive electrode active material 100 is obtained through the same process as in step S73.

[0122] Although not shown in the diagram, the additive elements may also be added in two stages: from additive element X1 source and additive element X2 source. Furthermore, the additive elements may be added in two stages: from a source of additive element X2 and from a source of additive element X3. Additive elements may be added during this process.

[0123] In this way, by separating the process of introducing multiple additive elements, the depth of each element can be determined. It may be possible to change the directional profile. For example, inside the positive electrode active material 100. Compared to this, it is possible to increase the concentration of specific additive elements in the surface layer. Also, the atoms of the transition metal M Based on a numerical standard, the ratio of the number of atoms of a specific additive element to that standard is determined to be more favorable in the surface layer than in the interior. And it can be made even higher.

[0124] This embodiment can be used in combination with other embodiments.

[0125] (Embodiment 2) In this embodiment, a coprecipitation method can be used to produce the positive electrode active material described in Embodiment 1. The synthesis apparatus will be explained using Figures 9 and 10.

[0126] The coprecipitation synthesis apparatus 170 shown in Figure 9 has a reaction tank 171, and the reaction tank 171 has a reaction vessel. The reaction vessel uses a separable flask at the bottom and a separable cover at the top. It is good to have one. Separable flasks can be cylindrical or round. If cylindrical, separate The flask has a flat bottom. Also, at least one inlet of the separable cover is used The atmosphere inside the reaction vessel 171 can be controlled. For example, the atmosphere can be an inert atmosphere. Preferably, for example, nitrogen is present. In that case, nitrogen flow is preferable. Furthermore, it is preferable to bubble nitrogen in the water 192 in the reaction vessel 171. Coprecipitation synthesis apparatus As shown in Figure 10, the 170 is connected to at least one inlet of the separable cover. A reflux condenser 191 may also be provided, and this reflux condenser 191 will allow the reaction vessel 171 to... The atmospheric gas, such as nitrogen, can be discharged, and the water can be returned to the reaction vessel 171. The atmosphere inside 71 is designed to vent gases generated by thermal decomposition reactions resulting from heat treatment. As long as the necessary amount of airflow is present, that's all that matters.

[0127] First, water 192 is placed in reaction vessel 171, then the acid solution and alkaline solution are added to the reaction vessel. Add to 171 dropwise. Note that the water 192 prepared in reaction vessel 171 is sometimes referred to as the filling liquid. . The impregnation liquid may be referred to as an adjustment liquid, which refers to the aqueous solution before the reaction, that is, the aqueous solution in the initial state. may be referred to.

[0128] Explain other configurations of the coprecipitation method synthesis apparatus 170 shown in FIGS. 9 and 10. The coprecipitation method synthesis apparatus 170 includes a stirring unit 172, a stirring motor 173, a thermometer 174, a tank 175, a pipe 176 , a pump 177, a tank 180, a pipe 181, a pump 182, a tank 186, a pipe 187, a pump 188, and a control device 190, etc.

[0129] The stirring unit 172 can stir the water 192 in the reaction tank 171, and further has a stirring motor 173 as a power source for rotating the stirring unit 172. The stirring unit 172 has a paddle-type stirring blade (referred to as a paddle blade), the paddle blade has two or more and six or less blades, and the blade may have an inclination of 40 degrees or more and 70 degrees or less.

[0130] The thermometer 174 can measure the temperature of the water 192. The temperature of the reaction tank 171 can be controlled using a heater and a cooling thermoelectric element, etc., so that the temperature of the water 1 92 becomes constant. Examples of the cooling thermoelectric element include a Peltier element. A pH meter (not shown) is also arranged in the reaction tank 171 and can measure the pH of the water 192.

[0131] Each tank can store different raw material aqueous solutions. For example, each tank can be filled with a transition metal M source or an acid solution, and an alkaline solution. A tank filled with water that functions as an impregnation liquid may be prepared. Each tank is provided with a pump, and by using the pump , the raw material aqueous solution can be dropped into the reaction tank 171 through a pipe. ​​​​Each pump can control the amount of raw material aqueous solution dispensed, i.e., the amount of liquid delivered. Alternatively, a valve may be installed in pipe 176 to control the amount of raw material aqueous solution dispensed, i.e., the amount of liquid delivered. .

[0132] The control device 190 includes a stirring motor 173, a thermometer 174, a pump 177, a pump 182, and It is electrically connected to the pump 188, and controls the rotation speed of the stirring section 172, the temperature of the water 192, The amount of each raw material aqueous solution dispensed can be controlled.

[0133] The rotational speed of the stirring section 172, specifically the rotational speed of the paddle blades, is, for example, 800 rpm or more. It is best to keep it below 00 rpm. Also, while maintaining the water 192 at a temperature between 50°C and 90°C, the above It is recommended to stir the mixture. At that time, it is recommended to drop the acid solution, etc., into the reaction vessel 171 at a constant rate. Of course The rotation speed of the paddle blades is not limited to a constant value and can be adjusted as needed. For example, inside reaction vessel 171 The rotation speed can be changed according to the liquid volume. Furthermore, the dropping rate of acidic solutions, etc., can also be adjusted. This is possible. It is advisable to adjust the dropping rate to maintain a constant pH in reaction vessel 171. Add an acidic solution or the like dropwise, and when the pH value deviates from the desired value, add an alkaline solution dropwise. The dropping rate may be controlled. The above pH value is 9.0 or higher and 11.0 or lower, preferably pH 9. It is best to keep it within the range of 0.8 to 10.3.

[0134] After the above process, the reaction product precipitates in the reaction vessel 171. The reaction product is complex hydroxide 98 The reaction may be described as coprecipitation or coprecipitation, and the step may be described as a coprecipitation step. There is a match.

[0135] This embodiment can be used in combination with other embodiments.

[0136] (Embodiment 3) In this embodiment, a positive electrode active material 100, which is an aspect of the present invention, will be described with reference to FIGS. 11 to 14. will be described.

[0137] The positive electrode active material 100 has secondary particles in which primary particles are aggregated. The positive electrode active material 100 may have voids inside. It may have voids inside.

[0138] <Contained elements> The positive electrode active material 100 contains at least one of lithium, transition metal M, oxygen, and additive element X. In this specification and the like, the additive element X refers to the combined additive element X1, additive element X2, and additive element X3. It shall be referred to as the combined additive element X1, additive element X2, and additive element X3.

[0139] The positive electrode active material 100 may be one in which the additive element X is added to a composite oxide represented by LiMO2. However, the positive electrode active material of an aspect of the present invention only needs to have the crystal structure of a lithium composite oxide represented by LiMO2, and its composition is not strictly limited to Li:M:O = 1:1:2. It may be said that the additive element X is added to a composite oxide represented by LiMO2. However, the positive electrode active material of an aspect of the present invention only needs to have the crystal structure of a lithium composite oxide represented by LiMO2, and its composition is not strictly limited to Li:M:O = 1:1:2. It is not limited to. It is not limited thereto.

[0140] Regarding the transition metal M, additive element X, and their preferred ratios included in the positive electrode active material 100, reference may be made to the description in Embodiment 1. Reference may be made to the description in Embodiment 1.

[0141] <Distribution of elements> The additive element X in the positive electrode active material 100 preferably has a concentration gradient. In particular, since the additive element X3 is added after the production of the composite oxide 99, it is likely to have a concentration gradient. For example, it is preferable that the positive electrode active material 100 has a surface layer portion and an interior, and the concentration of the additive element X3 in the surface layer portion is higher than that in the interior. Since the additive element X3 is added after the production of the composite oxide 99, it is likely to have a concentration gradient. For example, it is preferable that the positive electrode active material 100 has a surface layer portion and an interior, and the concentration of the additive element X3 in the surface layer portion is higher than that in the interior. It is preferable that the positive electrode active material 100 has a surface layer portion and an interior, and the concentration of the additive element X3 in the surface layer portion is higher than that in the interior. It is preferable.

[0142] Unlike the inside of the crystal, the particle surface is in a state where the bonds are broken, and during charging, ri Because lithium is released from this area, the lithium concentration tends to be lower than in the interior. The surface layer is prone to instability and the crystal structure is easily disrupted. Therefore, in LiMO2... A compound or alloy element X that is more chemically and structurally stable than the lithium composite oxide shown ( For example, if an oxide of additive element X is present in the surface layer, changes in the crystal structure can be suppressed more effectively. This is possible. Also, if the concentration of added element X3 in the surface layer is high, the electrolyte will decompose and produce It can also be expected that its corrosion resistance to acid will improve.

[0143] However, if the surface layer consists only of additive element X and oxygen, the lithium insertion / deinsertion pathway becomes blocked. There is a risk of peeling. Therefore, the surface layer has at least a transition metal M, and in the discharge state It also contains lithium and needs to have a pathway for lithium insertion and removal. Furthermore, the surface layer is It is preferable that the concentration of the transition metal M is higher than that of each additive element X.

[0144] Because the added element X has the distribution described above, the degradation of the positive electrode active material 100 is reduced even after charging and discharging. This means that the degradation of secondary batteries can be suppressed. Furthermore, it can result in a more safe secondary battery. can.

[0145] Furthermore, the transition metal M, especially cobalt and nickel, is uniformly dissolved in the entire positive electrode active material 100. It is preferable that this is the case.

[0146] Furthermore, in one aspect of the present invention, the positive electrode active material 100 is covered with a material that covers at least a portion of the positive electrode active material 100. A positive electrode active material composite having a covering layer may also be used. For example, the covering layer may be glass, oxide, and one or more of LiM2PO4 (M2 is one or more selected from Fe, Ni, Co, and Mn) can be used.

[0147] As the glass that the coating layer of the positive electrode active material composite has, a material having an amorphous part can be used For example, SiO2, SiO, Al2O3, TiO 2, Li4SiO4, Li3PO4, Li2S, SiS2, B2S3, GeS4, AgI , Ag2O, Li2O, P2O5, B2O3, and one or more selected from V2O5, etc. having a material, Li7P3S, or Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 < x < 2, 0 < y < 3), etc. can be used. The material having an amorphous part can be used in an entirely amorphous state or in the state of a crystallized glass (also called a glass ceramic) in which part is crystallized. It is desirable that the glass has lithium ion conductivity. Having lithium ion conductivity means having lithium ion diffusivity and lithium ion penetrability. Also, it is preferable that the glass has a melting point of 800 °C or lower, and more preferably 500 °C or lower. It is also preferable that the glass has electronic conductivity. Also, it is preferable that the glass has a softening point of 800 °C or lower. For example, Li2O - B2O3 - SiO2 - based glass can be used

[0148] Examples of the oxide that the coating layer of the positive electrode active material composite has include aluminum oxide, zirconium oxide , hafnium oxide, and niobium oxide, etc. Also, the coating layer of the positive electrode active material composite has ​​​​​​Examples of LiM2PO4 (M2 is one or more selected from Fe, Ni, Co, Mn) include , LiFePO4, LiNiPO4, LiCoPO4, LiMnPO4, LiFe a Ni b PO4, LiFe a Co b PO4, LiFe a Mn b PO4, LiNi a Co b PO4 , LiNi a Mn b PO4 (a + b is 1 or less, 0 < a < 1, 0 < b < 1), LiFe c N i d Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co d Mn e PO4 (c + d + e is 1 or less, 0 < c < 1, 0 < d < 1, 0 < e < 1), LiFe f Ni g Co h M n i PO4 (f + g + h + i is 1 or less, 0 < f < 1, 0 < g < 1, 0 < h < 1, 0 < i < 1), etc.

[0149] For the preparation of the coating layer of the cathode active material composite, a composite treatment can be used. Examples of the composite treatment include, for example, mechanical energy-based composite treatments such as the mechanochemical method, the mechanofusion method, and the ball milling method, liquid-phase reaction-based composite treatments such as the coprecipitation method, the hydrothermal method, and the sol-gel method, and gas-phase reaction-based composite treatments such as the barrel sputtering method, the ALD (Atomic Layer D eposition) method, the vapor deposition method, and the CVD (Chemical Vapor Dep osition) method. One or more of these composite treatments can be used. It can be used. Furthermore, as a composite treatment using mechanical energy, for example, Hosokawa Micron-sized picobonds can be used. In addition, in the compounding process, one or multiple It is preferable to perform several heat treatments.

[0150] <Ease of each additive element X to enter nickel sites> Below are the additive elements X: boron, magnesium, aluminum, calcium, titanium, Gallium, yttrium, zirconium, niobium, lanthanum, and hafnium are LiMo The layered rock salt type lithium composite oxide represented by 2 is stably present at the nickel site. I will explain the results of my calculations regarding whether it is possible. For comparison, I will also include the results for cobalt and manganese. This is also shown.

[0151] In this embodiment, the transition metal M is nickel, cobalt, and manganese, and nickel Using LiMO2, which has the highest proportion of ions, as a model, we evaluate it from the stabilization energy of the entire system. It was worth it.

[0152] Figure 11 shows the model used in the calculation. The nickel at replacement site 110, shown in the center of the model, The energy change when substituted with other metal elements was calculated. The more stable the nickel, the more... It can be said that it is an element that is likely to exist in the atmosphere.

[0153] The calculation conditions are shown in Table 1.

[0154] [Table 1]

[0155] The calculation results are shown in Figure 12. LS in the figure indicates low spin. Boron, aluminum, th Tan, gallium, yttrium, zirconium, niobium, lanthanum and hafnium When substitution is performed, it is more effective than when there is no substitution or when substitution is performed with cobalt or manganese. It had also stabilized.

[0156] <Effect of adding element X on suppressing surface structure changes> Next, among the additive elements X, gallium, aluminum, magnesium, and calcium were used. We will now explain the results of our calculations regarding the effect of suppressing structural changes in this case.

[0157] LiMo2, which has a high nickel content, will lose nickel as it undergoes repeated charging and discharging cycles. It is prone to cation mixing, which moves to the surface, and the surface has a structure of NiO (nickel oxide). It is thought to change over time. Nickel oxide is inert to battery reactions. Therefore, degradation occurs. To suppress this process, it is important to inhibit the structural change of the LiMO2 surface to NiO.

[0158] In this embodiment, the model before substitution, in which nickel moves to the lithium site, is used as the starting state. The calculations began. Also, assuming a high nickel content in LiMO2, the LiNiO2 model was used as the starting state. This is shown in Figure 13(A). Here, all lithium and nickel are octahedral sigma. It occupies space T108.

[0159] Following the initial state, the intermediate state is a structure in which nickel has moved to tetrahedral site 104 of the lithium layer. This is shown in Figure 13(B).

[0160] The final state was a structure in which the nickel occupied the octahedral site 108. This is shown in Figure 13(C). show.

[0161] Note that tetrahedral site 104 is a site that is ionically bonded with four oxygen atoms, and octahedral site Ito-108 is a site that is ionically bonded to six oxygen atoms.

[0162] In this embodiment, when the additive element X is substituted at the nickel site, the initial state is replaced with an intermediate state. We investigated whether structural changes to the nickel site would become less likely. The nickel site is shown by the dashed line in Figure 13(D). An example of substituting gallium is shown.

[0163] The calculation conditions are shown in Table 2. The initial result obtained when the additive element X is gallium is... The structures of the states and intermediate states are shown in Figures 14(A) and 14(B).

[0164] [Table 2]

[0165] In the structure of the initial state in Figure 14(A) and the intermediate state in Figure 14(B), the circumference of the substituted gallium No significant distortion occurred on the edges, and it is clear that gallium stably enters the nickel site. That's what happened.

[0166] Next, Table 3 shows the results of comparing the energy difference between the initial state and the intermediate state with and without the addition of element X. This will be shown.

[0167] [Table 3]

[0168] As is clear from Table 3, compared to the case without substitution, calcium, gallium, and aluminum Furthermore, the presence of additive element X, such as magnesium, allows for the exchange of nickel and lithium. This effect was more pronounced with gallium, aluminum, and magnesium.

[0169] From the above, by having gallium, aluminum, or magnesium as the additive element X Cationic mixing is suppressed, degradation of the positive electrode active material 100 is suppressed, and the capacity retention rate is improved. The possibility of an increase was suggested.

[0170] This embodiment can be used in combination with other embodiments.

[0171] (Embodiment 4) In this embodiment, the positive electrode active material produced by the manufacturing method described in the previous embodiment is This section describes examples of various shapes of secondary batteries.

[0172] [Coin-type rechargeable battery] An example of a coin-type rechargeable battery is described below. Figure 15(A) shows a coin-type (single-layer flattened) battery. Figure 15(B) is an external view of a secondary battery, and Figure 15(C) is a cross-section view of the battery. This is a view drawing. Coin-type rechargeable batteries are mainly used in small electronic devices. Coin-type batteries include button-type batteries.

[0173] In Figure 15(A), the overlapping of the components (up / down relationship and positional relationship) is shown for clarity. A schematic diagram is provided for clarity. Therefore, Figure 15(A) and Figure 15(B) are perfectly identical pairs. It is not intended as a diagram.

[0174] In Figure 15(A), the positive electrode 304, separator 310, negative electrode 307, spacer 322, and washer Two Shear 312s are stacked. These are sealed with a negative electrode can 302 and a positive electrode can 301. In Figure 15(A), the gasket for sealing is not shown. Spacer 322, Washer 312 protects the inside or can when crimping the positive electrode can 301 and the negative electrode can 302. It is used to fix the internal position. Spacer 322 and washer 312 are stainless steel. Use a resin or insulating material.

[0175] The positive electrode 304 is a laminated structure in which a positive electrode active material layer 306 is formed on a positive electrode current collector 305. .

[0176] To prevent a short circuit between the positive and negative electrodes, a separator 310 and a ring-shaped insulator 313 are connected to the positive electrode 304. They are positioned to cover the sides and top surfaces, respectively. The separator 310 is positioned more than the positive electrode 304. It has a large surface area.

[0177] Figure 15(B) is a perspective view of the completed coin-type rechargeable battery.

[0178] The coin-type rechargeable battery 300 consists of a positive electrode casing 301, which also serves as the positive terminal, and a negative electrode casing, which also serves as the negative terminal. 302 is insulated and sealed by a gasket 303 made of polypropylene or the like. The positive electrode 304 consists of a positive electrode current collector 305 and a positive electrode active material layer 306 provided in contact with it. It is formed by the following. The negative electrode 307 is provided in contact with the negative electrode current collector 308. It is formed by a negative electrode active material layer 309. Furthermore, the negative electrode 307 is limited to a laminated structure. Alternatively, lithium metal foil or a lithium-aluminum alloy foil may be used.

[0179] Furthermore, the positive electrode 304 and negative electrode 307 used in the coin-type secondary battery 300 are each made of live metal The layers only need to be formed on one side.

[0180] The positive electrode can 301 and negative electrode can 302 are made of nickel and aluminum, which are corrosion-resistant to the electrolyte. , metals such as titanium, or alloys thereof, and alloys of these with other metals (e.g., stainless steel) (Steel, etc.) can be used. In addition, nickel is used to prevent corrosion by electrolytes, etc. It is preferable to coat it with aluminum or the like. The positive electrode can 301 is a positive electrode 304 and the negative electrode can 3 02 is electrically connected to the negative electrode 307.

[0181] These negative electrode 307, positive electrode 304, and separator 310 are immersed in the electrolyte, as shown in Figure 15(C). As shown, with the positive electrode can 301 at the bottom, the positive electrode 304, separator 310, negative electrode 307, and negative electrode... The cans 302 are stacked in this order, and the positive electrode can 301 and the negative electrode can 302 are connected via the gasket 303. The coin-shaped rechargeable battery 300 is manufactured by crimping the parts together.

[0182] The above configuration results in high capacity, high charge / discharge capacity, and excellent cycle characteristics. This can be made into a coin-type rechargeable battery 300. Note that between the negative electrode 307 and the positive electrode 304 When a secondary battery having a solid electrolyte layer is used, the separator 310 can be made unnecessary. Cut.

[0183] [Cylindrical rechargeable battery] An example of a cylindrical secondary battery will be explained with reference to Figure 16(A). Cylindrical secondary battery 61 As shown in Figure 16(A), 6 has a positive electrode cap (battery cover) 601 on its top surface, and its sides and The battery can (outer casing) 602 is located on the bottom. These positive electrode cap 601 and battery can (outer casing) The container (602) is insulated by the gasket (insulating packing) 610.

[0184] Figure 16(B) is a schematic diagram showing a cross-section of a cylindrical secondary battery. The cylindrical rechargeable battery has a positive electrode cap (battery cover) 601 on the top surface, and on the sides and bottom It has a battery can (outer can) 602. These positive electrode cap 601 and battery can (outer can) 6 02 is insulated by gasket (insulating packing) 610.

[0185] Inside the hollow cylindrical battery can 602, there is a strip-shaped positive electrode 604 and a negative electrode 606 separated by a separator 6 A battery element is provided wound with 05 in between. Although not shown in the diagram, the battery element is center It is wound around the shaft. Battery casing 602 is closed at one end and open at the other. Can 602 contains metals such as nickel, aluminum, and titanium that are corrosion-resistant to the electrolyte. or using alloys thereof, and alloys of these with other metals (e.g., stainless steel). It can be present. Also, to prevent corrosion by the electrolyte, nickel and aluminum, etc. It is preferable to cover the battery can 602 with it. Inside the battery can 602, the positive electrode and the negative electrode The battery element, around which the separator is wound, is sandwiched between a pair of opposing insulating plates 608 and 609. It is filled with a non-aqueous electrolyte (not shown). ) is injected. The non-aqueous electrolyte can be the same as that used in coin-type rechargeable batteries. Cut.

[0186] Since the positive and negative electrodes used in cylindrical storage batteries are wound, active material is formed on both sides of the current collector. It is preferable that the height of the cylinder is greater than the diameter of the cylinder. The illustration shows a secondary battery 616 with a larger diameter, but it is not limited to this. The diameter of the cylinder is greater than the height of the cylinder. It may also be a larger secondary battery. With such a configuration, for example, the miniaturization of secondary batteries can be achieved. It is possible to measure this.

[0187] By using the positive electrode active material 100 obtained in the above embodiment as the positive electrode 604, high capacity and Furthermore, the cylindrical secondary battery 616 has high charge / discharge capacity and excellent cycle characteristics. It is possible.

[0188] The positive electrode 604 is connected to the positive electrode terminal (positive electrode current collector lead) 603, and the negative electrode 606 is connected to the negative electrode terminal The (negative current collector lead) 607 is connected. Both the positive terminal 603 and the negative terminal 607 are Metal materials such as aluminum can be used. The positive terminal 603 is connected to the safety valve mechanism 61 3. The negative terminals 607 are resistance-welded to the bottom of the battery can 602. Safety valve mechanism 613 This is a PTC (Positive Temperature Coefficient) element. It is electrically connected to the positive electrode cap 601 via the child 611. The safety valve mechanism 613 is electrically When the internal pressure of the pond rises above a predetermined threshold, the electrical current between the positive electrode cap 601 and the positive electrode 604 This disconnects the connection. Also, the PTC element 611 has resistance when the temperature rises. It is a thermal resistance element that increases resistance, and by limiting the amount of current due to the increase in resistance, it prevents abnormal heat generation. Therefore, PTC elements use barium titanate (BaTiO3)-based semiconductor ceramics, etc. You can use it.

[0189] Figure 16(C) shows an example of the energy storage system 615. The energy storage system 615 consists of multiple secondary batteries. It has 616. The positive electrode of each secondary battery is a conductor 624 separated by an insulator 625. It is in contact with and electrically connected to the control circuit 624 via the wiring 623. It is electrically connected to 0. Also, the negative terminal of each secondary battery is connected via wiring 626. It is electrically connected to the control circuit 620. The control circuit 620 is responsible for overcharging or over-discharging. A protective circuit or the like can be applied to prevent this.

[0190] Figure 16(D) shows an example of the energy storage system 615. The energy storage system 615 has multiple secondary power It has a battery 616, and multiple secondary batteries 616 are sandwiched between conductive plates 628 and 614. Multiple secondary batteries 616 are connected to conductive plates 628 and 614 by wiring 627. They are connected electrically. Multiple secondary batteries 616 may be connected in parallel or in series. They may be connected in parallel and then further connected in series. By configuring a power storage system 615 having a battery 616, it is possible to extract a large amount of power. can.

[0191] Multiple secondary batteries 616 may be connected in parallel and then further connected in series.

[0192] A temperature control device may be provided between multiple secondary batteries 616. If the secondary batteries 616 overheat... When this happens, the temperature control device cools the battery, and if the secondary battery 616 gets too cold, the temperature control device... The device can be heated. Therefore, the performance of the energy storage system 615 is affected by the outside temperature. It becomes less likely to happen.

[0193] Furthermore, in Figure 16(D), the energy storage system 615 has wiring 621 and distribution to the control circuit 620. They are electrically connected via wire 622. Wiring 621 is connected via conductive plate 628 to multiple twins The wiring 622 is connected to the positive terminal of the secondary battery 616, and the wiring 622 is connected to the negative terminal of the multiple secondary batteries 616 via the conductive plate 614. They are electrically connected to each other.

[0194] [Other structural examples of secondary batteries] Examples of secondary battery structures will be explained using Figures 17 and 18.

[0195] The secondary battery 913 shown in Figure 17(A) has terminals 951 and 952 inside the housing 930. It has a wound body 950. The wound body 950 is immersed in an electrolyte inside the housing 930. Terminal 952 is in contact with the housing 930, and terminal 951 is in contact with the housing by using insulating material, etc. It is not in contact with the body 930. Note that in Figure 17(A), for convenience, the housing 930 is separated. As shown in the diagram, in reality the wound body 950 is covered by the housing 930, and terminals 951 and 95 2 extends outside the casing 930. The casing 930 is made of a metal material (e.g., aluminum). Materials such as lum or resin can be used.

[0196] Furthermore, as shown in Figure 17(B), the housing 930 shown in Figure 17(A) is made of multiple materials. They may be formed. For example, the secondary battery 913 shown in Figure 17(B) has a housing 930a and a housing 9 30b is bonded together, and the area enclosed by the housing 930a and housing 930b is wound up 9 50 is provided.

[0197] For the casing 930a, insulating materials such as organic resin can be used. In particular, the antenna By using a material such as organic resin on the surface where the electric field of the secondary battery 913 is formed, Shielding can be suppressed. Furthermore, if the shielding of the electric field by the housing 930a is small, the housing 930a An antenna may be installed inside. For the housing 930b, for example, a metal material may be used. can.

[0198] Furthermore, the structure of the wound body 950 is shown in Figure 17(C). The wound body 950 is connected to the negative electrode 931 The coiled body 950 has a positive electrode 932 and a separator 933. The negative electrode 931 and the positive electrode 932 are stacked on top of each other with a sash in between, and the stacked sheet is rolled up. It is a wound body. Furthermore, the negative electrode 931, the positive electrode 932, and the separator 933 are stacked together. You can also stack multiple of them.

[0199] Furthermore, a secondary battery 91 having a wound body 950a as shown in Figures 18(A) to 18(C) It may also be 3. The wound body 950a shown in Figure 18(A) has a negative electrode 931 and a positive electrode 932, It has a separator 933 and a negative electrode 931 which has a negative electrode active material layer 931a. Positive electrode 93 2 has a positive electrode active material layer 932a.

[0200] By using the positive electrode active material 100 obtained in the above embodiment as the positive electrode 932, high capacity and In addition, it is possible to create a secondary battery 913 with high charge / discharge capacity and excellent cycle characteristics. .

[0201] The separator 933 has a wider width than the negative electrode active material layer 931a and the positive electrode active material layer 932a. It is wound so as to overlap the negative electrode active material layer 931a and the positive electrode active material layer 932a. Furthermore, the fact that the negative electrode active material layer 931a is wider than the positive electrode active material layer 932a is a safety consideration. This is preferable. Furthermore, a wound body 950a of this shape is preferable because it offers good safety and productivity. .

[0202] As shown in Figure 18(B), the negative electrode 931 is electrically connected to terminal 951. Terminal 951 It is electrically connected to terminal 911a. Also, the positive terminal 932 is electrically connected to terminal 952. Terminal 952 is electrically connected to terminal 911b.

[0203] As shown in Figure 18(C), the coiled body 950a and the electrolyte are covered by the housing 930, The next battery is 913. It is preferable to provide a safety valve, overcurrent protection element, etc., in the housing 930. The safety valve is a valve that opens when the inside of the housing 930 reaches a predetermined internal pressure in order to prevent the battery from rupturing. ru.

[0204] As shown in Figure 18(B), the secondary battery 913 may have a plurality of wound bodies 950a. By using multiple windings 950a, a secondary battery 913 with a larger charge / discharge capacity can be created. This is possible. Other elements of the secondary battery 913 shown in Figures 18(A) and (B) are shown in Figure 17(A). The description of the secondary battery 913 shown in (C) through (F) can be taken into consideration.

[0205] <Laminated rechargeable battery> Next, regarding an example of a laminate-type secondary battery, an example of an external view is shown in Figures 19(A) and 19( Figure B) shows the positive electrode 503, negative electrode 506, and separator 5 07, it has an outer casing 509, a positive lead electrode 510, and a negative lead electrode 511.

[0206] Figure 20(A) shows the external view of the positive electrode 503 and the negative electrode 506. The positive electrode 503 is the positive electrode current collector 50 The positive electrode has a positive electrode active material layer 502 formed on the surface of the positive electrode current collector 501. 503 has a region where the positive electrode current collector 501 is partially exposed (hereinafter referred to as the tab region). Negative electrode 506 has a negative electrode current collector 504, and the negative electrode active material layer 505 is formed on the surface of the negative electrode current collector 504. Furthermore, the negative electrode 506 is the region where the negative electrode current collector 504 is partially exposed, i.e., the tab region. It has a tab region. The area and shape of the tab regions of the positive and negative electrodes are shown in the example in Figure 20(A). It is not limited to that.

[0207] <Method for manufacturing laminated rechargeable batteries> Here, we will describe an example of a method for manufacturing a laminate-type secondary battery, as shown in Figure 19(A) in its external view. This will be explained using Figures 20(B) and 20(C).

[0208] First, the negative electrode 506, separator 507, and positive electrode 503 are stacked. (See Figure 20(B) for details.) The negative electrode 506, separator 507, and positive electrode 503 are shown. Here, there are 5 sets of negative electrodes and 5 sets of positive electrodes. An example using four sets is shown. It can also be called a laminate consisting of a negative electrode, a separator, and a positive electrode. Next, the positive electrode The tab regions of 503 are joined together, and the positive lead electrode 510 is made contact with the tab region of the outermost positive electrode. Perform the joining. For joining, ultrasonic welding, for example, may be used. Similarly, the tab region of the negative electrode 506 The regions are joined together, and the negative electrode lead electrode 511 is joined to the tab region of the outermost negative electrode.

[0209] Next, the negative electrode 506, separator 507, and positive electrode 503 are placed on the outer casing 509.

[0210] Next, as shown in Figure 20(C), the outer casing 509 is folded at the part indicated by the dashed line. Next, the outer perimeter of the exterior body 509 is joined. For joining, for example, heat compression bonding may be used. In order to allow the electrolyte 508 to be added later, a part (or one side) of the outer casing 509 A region that is not connected (hereinafter referred to as the inlet) is provided.

[0211] Next, the electrolyte 508 (not shown) is introduced into the outer casing 509 through the inlet provided in the outer casing 5 Introduce into the inside of 09. Introduce electrolyte 508 under reduced pressure or inert atmosphere. It is preferable to do so. And finally, the inlet is joined. In this way, the laminate type A secondary battery 500 can be manufactured.

[0212] By using the positive electrode active material 100 obtained in the above embodiment as the positive electrode 503, high capacity and Furthermore, it is possible to create a secondary battery 500 with high charge / discharge capacity and excellent cycle characteristics. .

[0213] [Example of a battery pack] Figure 2 shows an example of a secondary battery pack according to one embodiment of the present invention that can be wirelessly charged using an antenna. This will be explained using Figures 1(A) through 21(C).

[0214] Figure 21(A) shows the external appearance of the secondary battery pack 531, which has a thin rectangular parallelepiped shape. It can also be described as a thick, flat plate shape. Figure 21(B) shows the configuration of the secondary battery pack 531. This is an explanatory diagram. The secondary battery pack 531 consists of the circuit board 540 and the secondary battery 513. It has. A label 529 is attached to the secondary battery 513. The circuit board 540 has a seal. It is fixed by 515. The secondary battery pack 531 also has an antenna 517. .

[0215] The interior of the secondary battery 513 may have a structure with a wound body or a structure with a laminated body. That's fine.

[0216] In the secondary battery pack 531, for example, as shown in Figure 21(B), on the circuit board 540 It has a control circuit 590. The circuit board 540 is electrically connected to terminal 514. It is there. Also, the circuit board 540 has the antenna 517, the positive lead and negative lead of the secondary battery 513. One end of the lead, 551, is electrically connected to the other end of the positive and negative leads, 552.

[0217] Alternatively, as shown in Figure 21(C), a circuit system 59 is provided on the circuit board 540. 0a and circuit system 590b which is electrically connected to circuit board 540 via terminal 514. It may have the following:

[0218] Furthermore, the antenna 517 is not limited to a coil shape; for example, it may be linear or plate-shaped. Planar antenna, aperture antenna, traveling wave antenna, EH antenna, magnetic field antenna, dielectric An antenna such as a body antenna may be used. Alternatively, antenna 517 may be a flat conductor. This flat conductor can function as one of the conductors for electric field coupling. Antenna 517 functions as one of the two conductors of the capacitor. This is also possible. This allows for the exchange of power not only through electromagnetic and magnetic fields, but also through electric fields. Cut.

[0219] The secondary battery pack 531 has a layer 519 between the antenna 517 and the secondary battery 513. The layer 519 has the function of shielding electromagnetic fields, for example, from the secondary battery 513. For layer 519, for example, a magnetic material can be used.

[0220] [Positive electrode] The positive electrode has a positive electrode active material layer and a positive electrode current collector. The positive electrode active material layer has a positive electrode active material and a current collector. It may have an electrical material and a binder. The positive electrode active material may have the same properties as described in the previous embodiment. The positive electrode active material is prepared using the manufacturing method.

[0221] Alternatively, the positive electrode active material described in the previous embodiment may be used in combination with other positive electrode active materials.

[0222] Other cathode active materials include, for example, olivine-type crystal structures, layered rock salt-type crystal structures, or There are composite oxides that have a spinel-type crystal structure. For example, LiFePO4, LiFe Compounds such as O2, LiNiO2, LiMn2O4, V2O5, Cr2O5, and MnO2 exist. It can be done.

[0223] Furthermore, other positive electrode active materials include spinel-type crystal structures containing manganese, such as LiMn2O4. It is preferable to mix the lithium-containing material with lithium nickelate (LiNiO2 or LiNi 1-x M x O2 (0 < x < 1) (M = Co, Al, etc.)). By adopting such a configuration, the characteristics of the secondary battery can be improved.

[0224] Also, as another positive electrode active material, a lithium a manganese composite oxide represented by the composition formula Li b M c O d can be used. Here, the element M is preferably a metal element selected from those other than lithium and manganese, or silicon or phosphorus, and more preferably nickel. Also, when measuring the entire particles of the lithium manganese composite oxide, it is preferable to satisfy 0 < a / (b + c) < 2, c > 0, and 0.26 ≤ (b + c) / d < 0.5 during discharging. Note that the composition of metals, silicon, phosphorus, etc. in the entire particles of the lithium manganese composite oxide can be measured using, for example, ICP-MS (inductively coupled plasma mass spectrometer). Also, the oxygen composition of the entire particles of the lithium manganese composite oxide can be measured using, for example, EDX (energy dispersive X-ray analysis method). Also, in combination with ICP-MS analysis, it can be determined by using valence evaluation of melting gas analysis and XAFS (X-ray absorption fine structure) analysis. Note that the lithium manganese composite oxide refers to an oxide containing at least lithium and manganese, and may contain at least one element selected from the group consisting of chromium, cobalt, aluminum, nickel, iron, magnesium, molybdenum, zinc, indium, gallium, copper, titanium, niobium, silicon, and phosphorus. ​​​​​​​​​​

[0225] <Conductive material> Conductive materials, also called conductive additives or conductive imparters, are made of carbon materials. Between multiple active materials By attaching a conductive additive, multiple active materials are electrically connected to each other, increasing conductivity. Furthermore, "adhesion" refers only to the physical close contact between the active material and the conductive additive. Rather, when covalent bonding occurs, when bonding occurs by van der Waals forces, the active material When a conductive additive covers a portion of the surface, or when the conductive additive fits into the surface irregularities of the active material, This concept includes cases where there is no direct physical contact but there is an electrical connection.

[0226] A typical example of a carbon material used as a conductive material is carbon black (furnace black). (These include racks, acetylene black, graphite, etc.)

[0227] Furthermore, it is more preferable to use graphene or a graphene compound as the conductive material.

[0228] In this specification, graphene compounds refer to multilayer graphene, multigraphene, and graphene oxide. Graphene, multilayer graphene oxide, multi-graphene oxide, reduced graphene oxide, reduced Original multilayer graphene oxide, reduced multilayer graphene oxide, graphene quantum dots Includes the above. Graphene compounds are compounds that have carbon and have a shape such as a flat plate or sheet, and This refers to a two-dimensional structure formed by a six-membered ring of carbon. The structure can be described as a carbon sheet. Graphene compounds may have functional groups. Graphene compounds are preferably curved. It could be made up of carbon nanofibers.

[0229] In this specification, graphene oxide is defined as having carbon and oxygen, and having a sheet-like shape. This refers to those having functional groups, particularly epoxy groups, carboxyl groups, or hydroxyl groups.

[0230] In this specification, reduced graphene oxide refers to a material having carbon and oxygen, and in a sheet-like form. This refers to a material that has a shape and a two-dimensional structure formed of a six-membered carbon ring. It is also possible that a single reduced graphene oxide sheet will function, but multiple sheets stacked together will also work. Good. Reduced graphene oxide has a carbon concentration greater than 80 atomic percent and an oxygen concentration of It is preferable that the portion has a carbon concentration of 2 atomic percent or more and 15 atomic percent or less. By adjusting the oxygen concentration, even a small amount can function as a highly conductive material. Furthermore, reduced graphene oxide shows the intensity of the G-band and D-band in the Raman spectrum. A ratio of G / D of 1 or greater is preferable. A reduced oxide graph with such an intensity ratio is obtained. Even in small quantities, the compound can function as a highly conductive material.

[0231] Graphene and graphene compounds possess excellent electrical properties, including high conductivity, and high It may possess excellent physical properties such as high flexibility and high mechanical strength. Furthermore, graphene and graphene compounds have a sheet-like shape. Graphene compounds may have curved surfaces, enabling surface contact with low contact resistance. Furthermore, even thin materials can have very high conductivity, and a small amount can efficiently conduct electricity within the active material layer. It is possible to form a sac. Therefore, graphene or graphene compounds can be used as a conductive material. By using this method, the contact area between the active material and the conductive material can be increased. The chromium or graphene compound should cover more than 80% of the surface area of ​​the active material. It is preferable that a fen or graphene compound is attached to at least some of the active material particles. Furthermore, graphene or graphene compounds are present on at least a portion of the active material particles. It is preferable that they overlap. Also, the shape of graphene or graphene compound is the active material particle. Preferably, the shape matches at least a part of the shape of the active material particles. The shape of the active material particles is, for example, , the irregularities possessed by a single active material particle, or the irregularities formed by multiple active material particles Furthermore, graphene or a graphene compound surrounds at least a portion of the active material particles. It is preferable that graphene or graphene compounds have holes.

[0232] When using active material particles with a small particle size, for example, active material particles of 1 μm or less, The specific surface area of ​​this material is large, and therefore more conductive paths are needed to connect the active material particles. In such cases, graphene or GL can efficiently form conductive paths even in small quantities. It is preferable to use a rafen compound.

[0233] Because of the properties described above, secondary batteries that require rapid charging and rapid discharging are suitable for use with G Using lafen compounds as conductive materials is particularly effective. For example, in two-wheeled or four-wheeled vehicles. Dual-purpose rechargeable batteries, drone rechargeable batteries, etc., require rapid charging and rapid discharging characteristics. There are also cases where rapid charging characteristics are required for mobile electronic devices. Rapid discharge can also be described as high-rate charging and high-rate discharging. For example, 1C. This refers to charging and discharging at 2C or 5C or higher.

[0234] Furthermore, together with graphene or graphene compounds, graphene or graphene compounds form The materials used in the formation process may be mixed and used in the active material layer 200. For example, graphene Alternatively, the particles used as a catalyst when forming graphene compounds may be graphene or graph It may be mixed with graphene compounds. For example, silicon dioxide (SiO2, SiO2) can be used as a medium. x (x<2), aluminum oxide Particles containing iron, nickel, ruthenium, iridium, platinum, copper, germanium, etc. The following are examples. The particles are preferably such that the median diameter (D50) is 1 μm or less, and 100 It is more preferable that the value be less than or equal to nm.

[0235] <Binder> Examples of binders include styrene-butadiene rubber (SBR) and styrene-isoprene rubber. N-styrene rubber, acrylonitrile-butadiene rubber, butadiene rubber, ethylene- It is preferable to use a rubber material such as a propylene-diene copolymer. Fluororubber can be used.

[0236] Furthermore, it is preferable to use a water-soluble polymer as the binder. For example, polysaccharides can be used as the derivative. Cellulose (CMC), methylcellulose, ethylcellulose, hydroxypropylcellulose Cellulose derivatives such as lurose, diacetylcellulose, and regenerated cellulose, and starch. These can be used. In addition, these water-soluble polymers can be used in combination with the aforementioned rubber material. It is even preferable if used.

[0237] Alternatively, as a binder, polystyrene, polymethyl acrylate, polymethyl methacrylate can be used. Chill (polymethyl methacrylate, PMMA), sodium polyacrylate, polyvinyl Alcohol (PVA), polyethylene oxide (PEO), polypropylene oxide, Liimide, polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene Polyisobutylene, polyethylene terephthalate, nylon, polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), ethylene propylene diene polymer, It is preferable to use materials such as polyvinyl acetate or nitrocellulose.

[0238] You may use a combination of several of the binders mentioned above.

[0239] For example, a material with particularly excellent viscosity-modifying properties may be used in combination with other materials. For example, rubber materials have excellent adhesive and elastic properties, but when mixed with a solvent, viscosity adjustment is difficult. There are cases where this is difficult. In such cases, for example, it may be mixed with a material that has particularly excellent viscosity-modifying effects. This is preferable. As a material with particularly excellent viscosity adjustment effect, for example, a water-soluble polymer can be used. This is good. Furthermore, water-soluble polymers that are particularly excellent in viscosity adjustment include the aforementioned polysaccharides, for example Carboxymethylcellulose (CMC), methylcellulose, ethylcellulose, hydro Celluloses such as xypropylcellulose, diacetylcellulose, and regenerated cellulose. Derivatives and starches can be used.

[0240] Furthermore, cellulose derivatives such as carboxymethylcellulose are, for example, carboxymethyl Solubility increases by using salts such as sodium salts and ammonium salts of cellulose. This makes it easier for the substance to exert its effect as a viscosity modifier. The increased solubility makes it easier for the electrode to... It is also possible to improve the dispersibility of the active material and other components when creating the rally. In the details, cellulose and cellulose derivatives used as electrode binders are specified. Therefore, those salts shall also be included.

[0241] Water-soluble polymers stabilize viscosity by dissolving in water, and also function as active materials and binders. Other materials to be combined with them, such as styrene-butadiene rubber, are stable in aqueous solution. It can be dispersed. Furthermore, because it has functional groups, it is easily and stably adsorbed onto the surface of the active material. It is expected that this will happen. Also, cellulose derivatives such as carboxymethylcellulose are Many materials have functional groups such as hydroxyl groups and carboxyl groups. Therefore, it is expected that the polymers will interact with each other and exist to broadly cover the surface of the active material.

[0242] When a binder covering or in contact with the surface of the active material forms a film, it is considered a passivation film. It is also expected to play a role in suppressing the decomposition of the electrolyte. Here, the passive film is an electrolytic film. A film that does not conduct air, or a film with extremely low electrical conductivity, for example, on the surface of an active material When a dynamic film is formed, the decomposition of the electrolyte can be suppressed at the battery reaction potential. It can. Furthermore, the passivation film suppresses electrical conductivity, while lithium ions can conduct electricity. And even better.

[0243] <Positive electrode current collector> As the positive electrode current collector, metals such as stainless steel, gold, platinum, aluminum, and titanium, and this Highly conductive materials such as alloys can be used. Also, materials used for the positive electrode current collector It is preferable that the material does not dissolve at the positive electrode potential. Also, silicon, titanium, neodymium, sucrose Aluminum alloys with added elements that improve heat resistance, such as valdium and molybdenum, are used. It can be formed by metal elements that react with silicon to form silicides. This is also good. Examples of metallic elements that react with silicon to form silicides include zirconium and thi. Tan, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten Examples include cobalt and nickel. Positive electrode current collectors come in foil, plate, sheet, mesh, and perforated forms. Shapes such as metal-like or expanded metal-like can be used as appropriate. The positive electrode current collector is It is best to use a material with a thickness of 5 μm to 30 μm.

[0244] [Negative electrode] The negative electrode has a negative electrode active material layer and a negative electrode current collector. The negative electrode active material layer also has a conductive material and It may have a binder.

[0245] For example, alloy-based materials or carbon-based materials, and mixtures thereof, can be used as the negative electrode active material. It is possible to be there.

[0246] As a negative electrode active material, it is possible to perform charge and discharge reactions through alloying and dealloying reactions with lithium. Any suitable element can be used. For example, silicon, tin, gallium, aluminum, galvanic acid. Among the following, a small amount is found in luminum, lead, antimony, bismuth, silver, zinc, cadmium, indium, etc. Materials containing at least one element can be used. Such elements have a larger capacity compared to carbon. In particular, silicon has a high theoretical capacity of 4200 mAh / g. Therefore, silicon is used as the negative electrode active material. It is preferable to use lycon. Alternatively, compounds containing these elements may be used. Example For example, SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V 2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag3 Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3, I Examples include nSb and SbSn. Here, the charge-discharge reaction occurs through alloying and dealloying reactions with lithium. Elements capable of performing this action, and compounds containing such elements, are sometimes referred to as alloying materials. ru.

[0247] In this specification, SiO refers to silicon monoxide, for example. Alternatively, SiO refers to SiO x It can also be expressed as follows. Here, it is preferable that x has a value of 1 or one neighbor. For example x is preferably between 0.2 and 1.5, and more preferably between 0.3 and 1.2.

[0248] Carbon-based materials include graphite, easily graphitizable carbon (soft carbon), and poorly graphitizable carbon (hard carbon). Carbon, carbon nanotubes, graphene, carbon black, etc. can be used. .

[0249] Examples of graphite include artificial graphite and natural graphite. An example of artificial graphite is... Examples include carbon microbeads (MCMB), coke-based artificial graphite, and pitch-based artificial graphite. Here, spheroidal graphite, which has a spherical shape, can be used as the artificial graphite. For example, MCMB may have a spherical shape, which is preferable. Also, MCMB has a table Reducing the area is relatively easy and sometimes preferable. For example, natural graphite is... Examples include flaky graphite and spheroidized natural graphite.

[0250] Graphite is formed when lithium ions are inserted into it (during the formation of lithium-graphite intercalation compounds). It exhibits a low potential, similar to lithium metal (0.05V to 0.3V vs. Li / L). i + ). As a result, lithium-ion secondary batteries using graphite exhibit a high operating voltage. Yes, it is possible. Furthermore, graphite has a relatively high volume per unit volume and relatively small volume expansion. It is preferable because it has advantages such as being inexpensive and having higher safety compared to lithium metal.

[0251] Furthermore, titanium dioxide (TiO2) and lithium titanium oxide (Li4T) are used as negative electrode active materials. i5O 12 ), lithium-graphite intercalation compound (Li x C6), Niobium pentoxide (Nb2O5) Oxides such as tungsten oxide (WO2) and molybdenum oxide (MoO2) can be used. can.

[0252] Furthermore, the negative electrode active material has a Li3N-type structure, which is a lithium and transition metal binitride. Li 3-x M x N (M = Co, Ni, Cu) can be used. For example, Li 2.6 Co 0.4 The N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm²). 3 ) indicates And it is preferable.

[0253] When a lithium-transition metal binitride is used, lithium ions are included in the negative electrode active material, Combined with lithium-ion-free materials such as V2O5 and Cr3O8 as positive electrode active materials. This is preferable. By pre-desorbing the lithium ions contained in the positive electrode active material, the negative electrode active material is used. A lithium-transition metal composite can be used.

[0254] Furthermore, materials that undergo a conversion reaction can also be used as negative electrode active materials. For example, Lithium oxide, such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO). Transition metal oxides that do not form alloys with the negative electrode active material may be used. The resulting materials include Fe2O3, CuO, Cu2O, RuO2, Cr2O3, etc. CoS oxides 0.89 , sulfides such as NiS and CuS, Zn3N2, Cu3N, Ge3 Nitrides such as N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF3, etc. It can also occur with fluoride.

[0255] The conductive material and binder that the negative electrode active material layer may have are those that the positive electrode active material layer may have A conductive material and a binder similar to those used in this process can be used.

[0256] Furthermore, in addition to the same materials as the positive electrode current collector, copper and other materials can also be used as the negative electrode current collector. Furthermore, it is preferable to use a material that does not alloy with carrier ions such as lithium for the negative electrode current collector. It seems so.

[0257] [Electrolyte] One form of electrolyte is an electrolyte solution containing a solvent and an electrolyte dissolved in the solvent. This is possible. As the solvent for the electrolyte, an aprotic organic solvent is preferred, for example, ethyl acetate. Polyethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, Chloroethylene carbonate, vinylene carbonate, γ-butyrolactone, γ-valero Lactone, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl Methyl carbonate (EMC), methyl formate, methyl acetate, ethyl acetate, methyl propionate Tyl, ethyl propionate, propyl propionate, methyl butyrate, 1,3-dioxane, 1,4-Dioxane, dimethoxyethane (DME), dimethyl sulfoxide, diethyl ethanol methyl diglyme, acetonitrile, benzonitrile, tetrahydrofuran, One of the following, such as ruhoran or sultone, or any combination and ratio of two or more of these. It can be used as a percentage.

[0258] Furthermore, as the solvent for the electrolyte, an ionic liquid (a room-temperature molten salt) that is flame-retardant and non-volatile is used. Using one or more of these devices can cause the internal temperature of the energy storage device to rise due to internal short circuits or overcharging. Even if this occurs, it can prevent the rupture and ignition of the energy storage device. Ionic liquids contain cations and It consists of anions and contains organic cations and anions. It is used as an organic cation in electrolytes. And, quaternary ammonium cations, tertiary sulfonium cations, and quaternary phosphonium cations Aliphatic onium cations such as thion, imidazolium cations, and pyridinium catho Aromatic cations such as ammonium compounds can be used as anions in the electrolyte. methyl anions, monovalent methyl anions, fluorosulfonate anions, perfluoro Lucyl sulfonate anion, tetrafluoroborate anion, perfluoroalkylbone Rate anions, hexafluorophosphate anions, or perfluoroalkyl anions Examples include sphate anions.

[0259] Furthermore, examples of electrolytes to be dissolved in the above solvent include LiPF6, LiClO4, and Li AsF6, LiBF4, LiAlCl4, LiSCN, LiBr, LiI, Li2SO4 Li2B 10 Cl 10 Li2B 12 Cl 12 LiCF3SO3, LiC4F9SO 3, LiC(CF3SO2)3, LiC(C2F5SO2)3, LiN(CF3SO2) 2, LiN(C4F9SO2)(CF3SO2), LiN(C2F5SO2)2, Lithium Lithium salts such as mbiso(oxalate)borate (Li(C2O4)2, LiBOB) One type, or two or more of these types, can be used in any combination and ratio. .

[0260] The electrolyte used in the energy storage device may contain particulate waste or elements other than the constituent elements of the electrolyte (hereinafter simply It is preferable to use a highly purified electrolyte with a low content of impurities (also called "impurities"). Specifically, the weight ratio of impurities to the electrolyte is 1% or less, preferably 0.1% or less. More preferably, it is preferable to have a concentration of 0.01% or less.

[0261] Furthermore, the electrolyte contains vinylene carbonate, propanesultone (PS), and tert-butylbe. TBB (TBB), fluoroethylene carbonate (FEC), lithium bis(oxalate) LiBOB (Lithium-Borate), as well as dinitriles such as succinonitrile and adiponitrile. Additives such as compounds may be added. The concentration of the additive can be adjusted, for example, in the solvent in which the electrolyte is dissolved. In contrast, the amount should be between 0.1 wt% and 5 wt%.

[0262] Alternatively, a polymer gel electrolyte, obtained by swelling a polymer with an electrolyte solution, may be used.

[0263] Using polymer gel electrolytes enhances safety against leakage and other issues. Furthermore, secondary batteries... It is possible to make it thinner and lighter.

[0264] Examples of polymers that can be gelled include silicone gel, acrylic gel, and acrylonitrile gel. Polyethylene oxide gels, polypropylene oxide gels, fluorine polymers Gels and the like can be used. For example, polyalkyl substances such as polyethylene oxide (PEO) Polymers having a ylene oxide structure, PVDF, and polyacrylonitrile, and so Copolymers containing these can be used. For example, PVDF and hexafluoropropylene PVDF-HFP, a copolymer of (HFP), can be used. The polymer may have a porous structure.

[0265] [Separator] Examples of separators include cellulose fibers such as paper, nonwoven fabrics, and glass. Fibers, ceramics, or nylon (polyamide), vinylon (polyvinyl alcohol) Synthetic fibers using polyester, acrylic, polyolefin, and polyurethane (polyurethane-based fibers). Materials formed from the above can be used.

[0266] The separator may have a multilayer structure. For example, organic materials such as polypropylene and polyethylene. The material film contains ceramic-based materials, fluorine-based materials, polyamide-based materials, or a mixture thereof. A combination of these materials can be used as a coating. Examples of ceramic materials include aluminum oxide. Nium particles, silicon oxide particles, etc. can be used as ceramic materials. It is also possible to use glassy materials, but unlike the glass used in electrodes, electron conduction Low conductivity is preferable. Examples of fluorine-based materials include PVDF and polytetrafluorine. Polyethylene and the like can be used. Examples of polyamide materials include nylon and ara. Mids (meth-aramids, para-aramids), etc., can be used.

[0267] Coating with ceramic materials improves oxidation resistance, making it suitable for use as a separator during high-voltage charging. This can suppress degradation and improve the reliability of secondary batteries. Furthermore, by coating fluorine-based materials... This allows the separator and electrode to adhere more closely, improving the output characteristics. Coating with riamid-based materials, especially aramid, improves heat resistance, thus enhancing the safety of secondary batteries. It can improve sexual performance.

[0268] For example, a mixture of aluminum oxide and aramid material is coated on both sides of a polypropylene film. It may also be done by using aluminum oxide on the surface of the polypropylene film that is in contact with the positive electrode. A mixed material of aramid may be coated, and a fluorine-based material may be coated on the surface in contact with the negative electrode.

[0269] The contents of this embodiment can be freely combined with the contents of other embodiments.

[0270] (Embodiment 5) In this embodiment, an all-solid-state battery is constructed using the positive electrode active material 100 obtained in the above embodiment. An example of how to create it is shown.

[0271] As shown in Figure 22(A), a secondary battery 400 according to one embodiment of the present invention comprises a positive electrode 410 and a solid electrolytic cell. It has a solid layer 420 and a negative electrode 430.

[0272] The positive electrode 410 has a positive electrode current collector 413 and a positive electrode active material layer 414. It has a positive electrode active material 411 and a solid electrolyte 421. The positive electrode active material 411 is the same as described above. The positive electrode active material 100 obtained in the form of application is used. The positive electrode active material layer 414 is a conductive material It may also have a binder.

[0273] The solid electrolyte layer 420 has a solid electrolyte 421. The solid electrolyte layer 420 has a positive electrode 410 and It is located between the negative electrodes 430 and does not have either the positive electrode active material 411 or the negative electrode active material 431. It is a domain.

[0274] The negative electrode 430 has a negative electrode current collector 433 and a negative electrode active material layer 434. It has a negative electrode active material 431 and a solid electrolyte 421. The negative electrode active material layer 434 is conductive It may have a material and a binder. Furthermore, metallic lithium may be used as the negative electrode active material 431. If present, there is no need to form particles, so as shown in Figure 22(B), the solid electrolyte 421 is present. It is possible to have a negative electrode 430 without a negative electrode. If metallic lithium is used for the negative electrode 430, secondary battery 4 It is preferable that the energy density of 00 can be improved.

[0275] The solid electrolyte 421 in the solid electrolyte layer 420 may be, for example, a sulfide-based solid electrolyte or an acid Compound-based solid electrolytes, halogenated solid electrolytes, etc., can be used.

[0276] Sulfide-based solid electrolytes include thiolysicone-based (Li 10 GeP2S 12 Li 3.25 Ge 0.25 P 0.75 S4, etc.), sulfide glass (70Li2S・30P2S5, 30Li2 S·26B2S3·44LiI, 63Li2S·36SiS2·1Li3PO4, 57L i2S・38SiS2・5Li4SiO4, 50Li2S・50GeS2, etc.), sulfide crystals Crystallized glass (Li7P3S 11Li 3.25 P 0.95 Contains S4, etc. Sulfide-based Solid electrolytes include materials with high conductivity, can be synthesized at low temperatures, and are relatively soft. It has advantages such as the conductivity path being easily maintained even after repeated charging and discharging.

[0277] Oxide-based solid electrolytes include materials having a perovskite-type crystal structure (La 2 / 3-x Li 3x Materials having a NASICON-type crystal structure (Li 1-Y Al Y Ti 2- Y (PO4)3 etc.) Materials having a garnet-type crystal structure (Li7La3Zr2O 12 etc. ), materials having a LISICON-type crystal structure (Li 14 ZnGe4O 16 etc.), LLZO (Li7La3Zr2O 12 ), oxide glass (Li3PO4-Li4SiO4, 50L i4SiO4·50Li3BO3 etc.), oxide crystallized glass (Li 1.07 Al 0.69 Ti 1.46 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 etc. is included. Oxide-based solid electrolytes have advantages such as being stable in the atmosphere.

[0278] Halide-based solid electrolytes include LiAlCl4, Li3InBr6, LiF, and LiCl These include LiBr, LiI, etc. Furthermore, these halide-based solid electrolytes are porous Composite materials filled with aluminum oxide or porous silica pores are also solid electrolytes. It can be used as such.

[0279] Also, different solid electrolytes may be mixed and used.

[0280] Among them, Li 1+x Al x Ti 2-x (PO4)3( 0 < x < 1) (hereinafter referred to as LATP) contains aluminum and titanium, which are elements that the positive electrode active material used in the secondary battery 400 of one aspect of the present invention may have. Therefore, a synergistic effect can be expected for improving the cycle characteristics, which is preferable. In addition, an improvement in productivity due to reduction of processes can also be expected. In the present specification and the like, the NASICON-type crystal structure is a compound represented by M2(XO4)3 (M: transition metal, X: S, P, As, Mo, W, etc.), and has a structure in which MO6 octahedra and XO4 tetrahedra share vertices and are three-dimensionally arranged.

[0281]

[0282] <Outer package and shape of secondary battery> For the outer package of the secondary battery 400 of one aspect of the present invention, various materials and shapes can be used, but it preferably has a function of pressing the positive electrode, the solid electrolyte layer, and the negative electrode.

[0282]

[0283] For example, FIG. 23 is an example of a cell for evaluating the materials of an all-solid-state battery. FIG. 23(A) is a schematic cross-sectional view of the evaluation cell. The evaluation cell has a lower member 761, an upper member 762, and a fixing screw or wing nut 764 for fixing them. By rotating the pressing screw 763, the electrode plate 753 is pressed to fix the evaluation material. An insulator 766 is provided between the lower member 761 and the upper member 762 made of stainless steel material. Also, an O-ring 765 for sealing is provided between the upper member 762 and the pressing screw 763. ​

[0284] The evaluation material is placed on an electrode plate 751, surrounded by an insulating tube 752, and subjected to electrical stimulation from above. The material is being pressed by the polarity plate 753. This is a magnified, oblique view of the area around the evaluation material. The figure is Figure 23(B).

[0285] As an example of the evaluation material, we show a stacked structure consisting of a positive electrode 750a, a solid electrolyte layer 750b, and a negative electrode 750c. The cross-sectional view is shown in Figure 23(C). Note that the same part is shown in Figures 23(A) to (C). The same symbol is used for the location.

[0286] The electrode plate 751 and lower member 761, which are electrically connected to the positive electrode 750a, are the positive electrode It can be said that this corresponds to a terminal. It is an electrode plate electrically connected to the negative electrode 750c. 753 and the upper member 762 can be said to correspond to the negative electrode terminal. Electrode plate While applying pressure to the evaluation material via the 751 and electrode plate 753, electrical resistance and other parameters are measured. It can be measured.

[0287] Furthermore, the outer casing of the secondary battery according to one aspect of the present invention uses a package with excellent airtightness. This is preferable. For example, a ceramic package or a resin package can be used. Furthermore, when sealing the outer casing, it is necessary to block out outside air and create a sealed atmosphere, for example, a glove box. It is preferable to perform this within the box.

[0288] Figure 24(A) shows a secondary battery according to one embodiment of the present invention, having a different exterior and shape from that shown in Figure 23. A perspective view is shown. The secondary battery in Figure 24(A) has external electrodes 771 and 772 and multiple packs. It is sealed with an outer casing that includes a cage member.

[0289] An example of a cross-section cut along the dashed line in Figure 24(A) is shown in Figure 24(B). Positive electrode 750a, The laminate having a solid electrolyte layer 750b and a negative electrode 750c has an electrode layer 773a provided on a flat plate. The package member 770a is cut, the frame-shaped package member 770b is cut, and the electrode layer 7 is on the flat plate. The package member 770c, which has 73b provided, is enclosed and sealed by the structure. The package members 770a, 770b, and 770c contain insulating materials, such as resin materials and Ceramics can be used.

[0290] The external electrode 771 is electrically connected to the positive electrode 750a via the electrode layer 773a, and the positive electrode terminal It functions as such. In addition, the external electrode 772 electrically connects with the negative electrode 750c via the electrode layer 773b. It is connected to the terminal and functions as a negative terminal.

[0291] By using the positive electrode active material 100 obtained in the above embodiment, high energy density and good This makes it possible to realize all-solid-state secondary batteries with favorable output characteristics.

[0292] The contents of this embodiment can be appropriately combined with the contents of other embodiments.

[0293] (Embodiment 6) This embodiment is an example of a secondary battery different from the cylindrical secondary battery shown in Figure 16(D). Figure 25(C) shows an example of applying a secondary battery to an electric vehicle (EV).

[0294] Electric vehicles have a first battery 1301a, 1301 as the main secondary battery for propulsion. b and a second battery that supplies power to the inverter 1312 which starts the motor 1304. 1311 is installed. The second battery 1311 is the cranking battery (star Also called a ter battery. The second battery 1311 can output high power if Often, high capacity is not required, and the capacity of the second battery 1311 is less than that of the first battery. It is smaller compared to 1301a and 1301b.

[0295] The internal structure of the first battery 1301a is as shown in Figure 17(A) or Figure 18(C) It may be a molded type, or it may be a laminated type as shown in Figure 19(A) or Figure 19(B). Furthermore, the first battery 1301a may also be the all-solid-state battery of Embodiment 4. By using the all-solid-state battery of Embodiment 4 in battery 1301a, a high capacity can be achieved. This improves safety and allows for miniaturization and weight reduction.

[0296] In this embodiment, the first batteries 1301a and 1301b are connected in parallel. An example is shown, but you can connect three or more in parallel. Also, with the first battery 1301a If sufficient power can be stored, the first battery 1301b may not be necessary. By constructing a battery pack with a secondary battery, it is possible to extract a large amount of power. The number of secondary batteries may be connected in parallel, in series, or in parallel. After being connected, they may be further connected in series. Multiple secondary batteries are also called a battery pack.

[0297] Furthermore, in the case of automotive secondary batteries, tools are used to cut off power from multiple secondary batteries. It has a service plug or circuit breaker that can cut off high voltage without any effort, and the first It is provided in the battery 1301a.

[0298] Furthermore, the power from the first batteries 1301a and 1301b is mainly used to rotate the motor 1304. It is used to power 42V automotive components (electric power) via the DC-DC circuit 1306. (Power steering 1307, heater 1308, defogger 1309, etc.) It supplies power. Even when the rear wheel has a rear motor 1317, the first battery 13 01a is used to rotate the rear motor 1317.

[0299] Furthermore, the second battery 1311 is connected to 14V automotive components via the DC-DC circuit 1310. It supplies power to the audio system (1313), power windows (1314), lights (1315), etc. do.

[0300] Furthermore, the first battery 1301a will be explained using Figure 25(A).

[0301] Figure 25(A) shows an example where nine rectangular rechargeable batteries 1300 are combined into a single battery pack 1415. This shows that nine rectangular secondary batteries 1300 are connected in series, and one electrode is insulated or The other electrode is fixed with a fixing part 1413, and the other electrode is fixed with a fixing part 1414 made of an insulator. This embodiment shows an example where the battery is fixed with fixing parts 1413 and 1414. The vehicle may be housed in a storage box (also called an enclosure). Since vibration or shaking is expected to be applied from the fixed parts 1413, 1414 It is preferable to secure multiple secondary batteries in a battery housing box or the like. The electrodes are electrically connected to the control circuit unit 1320 by wiring 1421. One electrode is electrically connected to the control circuit unit 1320 by wiring 1422.

[0302] Furthermore, the control circuit section 1320 uses a memory circuit that includes a transistor made of oxide semiconductor. It may be included. A charging control circuit having a memory circuit including an oxide semiconductor transistor. , or the battery control system, BTOS (Battery operating system) When referred to as em (or Battery oxide semiconductor) There is.

[0303] It is preferable to use a metal oxide that functions as an oxide semiconductor. For example, as an oxide In-M-Zn oxide (element M is aluminum, gallium, yttrium, copper, vanadium) Dium, beryllium, boron, titanium, iron, nickel, germanium, zirconium, mo Ribdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or It is preferable to use metal oxides such as one or more selected from magnesium. In particular, acid In-M-Zn oxides that can be applied as oxides are CAAC-OS(C-Axis Ali gned Crystal Oxide Semiconductor), CAC-OS (Cloud-Aligned Composite Oxide Semiconductor It is preferable that it be a ctor. Also, as an oxide, In-Ga oxide, In-Zn Oxides may be used. CAAC-OS has multiple crystalline regions, and these multiple crystalline regions This is an oxide semiconductor in which the c-axis is oriented in a specific direction. The specific direction is CAA. The thickness direction of the C-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or CAAC-OS This is the normal direction to the surface of the film. Furthermore, a crystalline region is a region where the atomic arrangement exhibits periodicity. Furthermore, if we consider the atomic arrangement as a lattice arrangement, then a crystalline region is also a region where the lattice arrangement is aligned. Furthermore, CAAC-OS has regions where multiple crystalline regions are connected in the ab-plane direction. Furthermore, the region in question may have distortion. Distortion refers to the area where multiple crystal regions are connected. Within the region, between a region with aligned lattice arrangements and another region with aligned lattice arrangements, This refers to the area where the orientation changes. In other words, CAAC-OS is c-axis oriented and ab-plane oriented. It is an oxide semiconductor that does not exhibit clear orientation. Furthermore, CAC-OS is, for example, The elements constituting the metal oxide are 0.5 nm to 10 nm, preferably 1 nm to 3 nm. It is a component of a material that is unevenly distributed with a size of less than or near nm. In the following, gold In the group oxide, one or more metal elements are unevenly distributed, and the region containing the metal element is 0 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or near that size. A mixed state of these elements is also called a mosaic or patchy appearance.

[0304] Furthermore, CAC-OS is a system where the material separates into a first region and a second region, resulting in a mosaic effect. This results in a cloud-like structure, where the first region is distributed within the membrane (hereinafter also referred to as a cloud-like structure). Therefore, CAC-OS is a mixture of the first region and the second region. It is a composite metal oxide having the following configuration.

[0305] Here, In for the metal elements constituting CAC-OS in In-Ga-Zn oxide The atomic ratios of Ga and Zn are expressed as [In], [Ga], and [Zn] respectively. To note, for example, in CAC-OS in In-Ga-Zn oxide, the first region is This is the region where [In] is greater than the [In] in the composition of the CAC-OS film. The second region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Yes. Or, for example, in the first region, [In] is greater than [In] in the second region. This is a region where the [Ga] is large and smaller than the [Ga] in the second region. In the second region, [Ga] is greater than [Ga] in the first region, and [In This is a region smaller than [In] in the first region.

[0306] Specifically, the first region mentioned above is mainly composed of indium oxide, indium zinc oxide, etc. This is the region. Furthermore, the second region mentioned above includes gallium oxide, gallium zinc oxide, etc. This is the region in which is the principal component. In other words, the first region described above is called the region in which In is the principal component. It can be replaced. Furthermore, the second region mentioned above can be rephrased as the region with Ga as the main component. It is possible.

[0307] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0308] For example, in CAC-OS in In-Ga-Zn oxide, energy-dispersive X-ray spectroscopy is used. Law(EDX:Energy Dispersive X-ray spectrosco The EDX mapping obtained using py) shows the region with In as the main component (the first region) It has a structure in which a region mainly composed of ) and a region mainly composed of Ga (the second region) are unevenly distributed and mixed. This can be confirmed.

[0309] When CAC-OS is used in a transistor, the conductivity is due to the first region and the second region The insulating properties resulting from this work in a complementary manner to enable the switching function (On / The function to turn it off can be added to CAC-OS. In other words, CAC-OS is In part of the material, it has conductive properties, and in part of the material, it has insulating properties, and the whole material It has the function of a semiconductor. By separating the conductive function and the insulating function, dual This allows for maximizing the functionality of the transistor. Therefore, CAC-OS is used in transistors. As a result, high on-current (I on ), high field-effect mobility (μ), and good switching This enables the implementation of a specific action.

[0310] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and CA. It may have two or more of the following: C-OS, nc-OS, and CAAC-OS.

[0311] Furthermore, since it can be used in high-temperature environments, the control circuit section 1320 uses an oxide semiconductor. It is preferable to use a transistor. To simplify the process, control circuit section 13 20 may be formed using a unipolar transistor. An oxide semiconductor is used for the semiconductor layer. The transistor has a wider operating ambient temperature range than single-crystal Si, from -40°C to 150°C. Furthermore, the characteristics of secondary batteries change less when heated compared to single-crystal Si transistors. The off-current of a transistor using a single-ended circuit is below the measurement limit even at 150°C, but The off-current characteristics of a silicon transistor are highly temperature-dependent. For example, at 150°C, In crystalline silicon transistors, the off-current increases, and the current on / off ratio does not become sufficiently large. The control circuit unit 1320 can improve safety. Also, the above embodiment can be obtained By combining the positive electrode active material 100 with a secondary battery that uses it as the positive electrode, the safety aspects are considered. A multiplicative effect can be obtained.

[0312] The control circuit section 1320, which uses a memory circuit including an oxide semiconductor transistor, To address the causes of instability such as microshorts, it functions as an automatic control device for secondary batteries. It can also be done. Functions to eliminate the cause of instability include overcharging prevention, overcurrent prevention, and charging Overheating control, cell balancing in battery packs, over-discharge prevention, remaining charge indicator, temperature-dependent charging voltage. and automatic current control, charging current control according to the degree of degradation, micro-short abnormal behavior detection, Examples include anomaly prediction related to micro-shorts, and at least one of these functions is required. The control circuit unit 1320 has this capability. Furthermore, it enables the miniaturization of the automatic control device for the secondary battery.

[0313] Furthermore, a microshort refers to a tiny short circuit inside a secondary battery. It's not a case of the positive and negative electrodes of the battery being short-circuited to the point where charging and discharging are impossible, but rather a very small short circuit. This refers to the phenomenon where a small short-circuit current flows. It occurs for a relatively short time and in a small area. Even in such conditions, large voltage changes occur, and these abnormal voltage values ​​affect the subsequent charging and discharging of the secondary battery. This may affect the estimation of electrical conditions, etc.

[0314] One of the causes of microshorts is that the positive electrode active material deteriorates due to multiple charge-discharge cycles. Due to the uneven distribution, localized current concentration occurs in parts of the positive and negative electrodes, causing the separator to... Some parts may stop functioning, or microscopic side effects may occur due to the generation of side reaction products. It is said that a short circuit has occurred.

[0315] In addition to detecting micro-shorts, the control circuit unit 1320 also detects the terminal voltage of the secondary battery. It can also be said that it detects and manages the charging and discharging state of the secondary battery. For example, to prevent overcharging, it can charge the battery. It is possible to turn off both the output transistor and the cutoff switch of the electrical circuit almost simultaneously. Cut.

[0316] Furthermore, an example of a block diagram of the battery pack 1415 shown in Figure 25(A) is shown in Figure 25(B). .

[0317] The control circuit unit 1320 includes at least a switch to prevent overcharging and a switch to prevent over-discharging. A switch section 1324 including a switch, and a control circuit 1322 that controls the switch section 1324, The control circuit unit 1320 has a voltage measuring unit for the first battery 1301a. The secondary battery has upper and lower voltage limits set, as well as an upper limit on the current supplied from an external source, and an upper limit on the current supplied from an external source. It limits the upper limit of the output current, etc. Within the range between the lower limit voltage and the upper limit voltage of the secondary battery, The voltage is within the recommended operating range; if it falls outside that range, switch unit 1324 activates. It functions as a protection circuit. Furthermore, the control circuit unit 1320 controls the switch unit 1324. It can also be called a protection circuit to prevent over-discharge and over-charge. For example, it can prevent overcharging. When the control circuit 1322 detects a voltage, the switch on the switch unit 1324 is turned off. This interrupts the current. Furthermore, a PTC element is provided in the charge / discharge path to respond to the rise in temperature. A function to interrupt the current may be provided. Also, the control circuit unit 1320 has an external terminal 132 It has terminal 5 (+IN) and an external terminal 1326 (-IN).

[0318] The switch section 1324 consists of an n-channel transistor and a p-channel transistor. It can be constructed by combining these. The switch section 1324 uses single-crystal silicon. Switches are not limited to those having Si transistors; for example, they can also have Ge (germanium), Si Ge (silicon germanium), GaAs (gallium arsenide), GaAlAs (gallium arsenide) Aluminum arsenide, InP (indium phosphide), SiC (silicon carbide), Zn Se (zinc selenide), GaN (gallium nitride), GaO x (Gallium oxide; x is greater than 0) The switch section 1324 may be formed using a power transistor having a large real number (or similar). Furthermore, memory elements using OS transistors can be integrated into circuits using Si transistors, etc. Because it can be freely arranged by layering, integration can be easily carried out. The transistor can be manufactured using the same manufacturing equipment as for the Si transistor. Therefore, it can be manufactured at low cost. That is, an OS transistor is used on the switch section 1324. The control circuit unit 1320 can be stacked and integrated into a single chip. Since the volume occupied by the road section 1320 can be reduced, miniaturization becomes possible.

[0319] The first batteries, 1301a and 1301b, primarily supply power to 42V (high-voltage) in-vehicle equipment. The second battery 1311 supplies power to 14V (low-voltage) in-vehicle equipment. .

[0320] In this embodiment, both the first battery 1301a and the second battery 1311 are lithium An example using a mu-ion secondary battery is shown. The second battery 1311 is a lead-acid battery, an all-solid-state battery. Alternatively, an electric double-layer capacitor may be used. For example, the all-solid-state battery of Embodiment 4 may be used. It may be. By using the all-solid-state battery of Embodiment 4 for the second battery 1311, high capacity This allows for miniaturization and weight reduction.

[0321] Furthermore, the regenerative energy from the rotation of the tire 1316 is transmitted to the motor 13 via the gear 1305. It is sent to 04 and from the motor controller 1303 and battery controller 1302 The second battery 1311 is charged via the control circuit unit 1321. The first battery 1301a is charged from the controller 1302 via the control circuit unit 1320. Alternatively, the first battery controller 1302 can be accessed via the control circuit unit 1320. The battery 1301b is charged. In order to efficiently charge the regenerative energy, the first battery It is desirable that the TTTERI 1301a and 1301b can be fast-charged.

[0322] The battery controller 1302 controls the charging voltage of the first batteries 1301a and 1301b. The charging current and other parameters can be set. The battery controller 1302 uses two The charging conditions can be set according to the charging characteristics of the next battery, enabling rapid charging.

[0323] Also, although not shown in the diagram, when connecting an electric vehicle to an external charger, the charger's power supply The connection cable for the battery controller or charger is electrically connected to the battery controller 1302. The power supplied from the external charger is transmitted via the battery controller 1302 to the first Charges batteries 1301a and 1301b. Also, depending on the charger, a control circuit may be installed. Although it is possible to avoid overcharging, the functions of the battery controller 1302 may not be used. To prevent this, the first batteries 1301a and 1301b are charged via the control circuit unit 1320. It is preferable to include a control circuit in the charger's outlet or the charger's connection cable. It may also be equipped with. The control circuit unit 1320 is an ECU (Electronic Control Unit). It is sometimes called the CAN bus unit. The ECU is a CAN bus unit installed in electric vehicles. It connects to the Controller Area Network. CAN is connected to the in-vehicle LA. It is one of the serial communication standards used as N. Also, ECU stands for Microcomputer. It includes data. Furthermore, the ECU uses either a CPU or a GPU.

[0324] External chargers installed at charging stations and other locations use 100V outlets and 200V outlets. There are various types, such as Cent, 3-phase 200V and 50kW. In addition, external charging is possible using contactless power supply methods, etc. It can also be charged by receiving power from electrical equipment.

[0325] For rapid charging, a secondary battery capable of withstanding high-voltage charging is required to achieve short charging times. A pond is desired.

[0326] Furthermore, the secondary battery of this embodiment described above has a positive electrode active material 10 obtained in the above embodiment. 0 is used. Furthermore, graphene is used as the conductive material, and the electrode layer is made thicker to increase the load capacity. By suppressing capacity degradation and maintaining high capacity, the electrical characteristics are significantly improved as a synergistic effect. This enables the realization of a secondary battery. It is particularly effective for secondary batteries used in vehicles, and is effective against the total weight of the vehicle. Without increasing the weight ratio of the secondary battery, it is possible to achieve a longer driving range, specifically a longer driving range per charge. We can provide vehicles with a range of 500km or more.

[0327] In particular, the secondary battery of the above-described embodiment is a positive electrode active material 100 as described in the above-described embodiment. By using this method, the operating voltage of the secondary battery can be increased, and as the charging voltage increases, usage The capacity that can be increased. Also, the positive electrode active material 1 described in the above embodiment By using 00 as the positive electrode, it is possible to provide a secondary battery for vehicles with excellent cycle characteristics. ru.

[0328] Next, we will discuss an example in which a secondary battery, which is one aspect of the present invention, is implemented in a vehicle, typically a transport vehicle. I will explain.

[0329] Furthermore, the secondary battery shown in any one of Figures 16(D), 18(C), or 25(A) is used in the vehicle. When installed, it can be used in hybrid vehicles (HV), electric vehicles (EV), or plug-in hybrid vehicles. It enables the realization of next-generation clean energy vehicles such as plug-in hybrid vehicles (PHVs). Furthermore, agricultural machinery... Motorized bicycles including electric assist bicycles, motorcycles, electric wheelchairs, electric carts, small or large ships, submarines, aircraft such as fixed-wing and rotary-wing aircraft, rockets, artificial satellites, space Rechargeable batteries can also be installed in transport vehicles such as probes, planetary probes, and spacecraft. One embodiment of the present invention can be a high-capacity secondary battery. These secondary batteries are suitable for miniaturization and weight reduction, and can be ideally used in transport vehicles.

[0330] In Figures 26(A) to (D), an example of a mobile body using one aspect of the present invention is shown, for transport Let's look at an example of a vehicle. The automobile 2001 shown in Figure 26(A) uses electricity as its power source for driving. It is an electric vehicle that uses a motor. Or, it is a vehicle that uses an electric motor and an engine as the power source for driving. This is a hybrid vehicle that can use the appropriate selection of gin. It is equipped with a secondary battery. When installing, the example of the secondary battery shown in Embodiment 3 is installed in one or more locations. The automobile 2001 shown in Figure 26(A) has a battery pack 2200, and the battery pack is multiple It has a secondary battery module to which a secondary battery is connected. Furthermore, electricity is supplied to the secondary battery module. It is preferable to have a charging control device that is connected to the target.

[0331] Furthermore, the automobile 2001 has a secondary battery that can be plugged in or wirelessly connected. It can be charged by receiving power from an external charging facility using a contact-type power supply system, etc. In this regard, the charging method and connector specifications are CHAdeMO® or CHAdeMO®. It may be done appropriately using the prescribed method, such as Bo.Charging equipment is a charging station installed in a commercial facility. It can be powered by an external source, or even by a household power supply. For example, plug-in technology can be used to power it from an external source. The power supply from these sources allows the battery storage device installed in the automobile 2001 to be charged. This is done by converting AC power to DC power via a conversion device such as an AC / DC converter. It is possible.

[0332] Although not shown in the diagram, a power receiving device is mounted on the vehicle, and power is supplied wirelessly from a ground-based power transmission device. It can also be charged by doing so. In this contactless power supply method, the power transmission device is located on the road or exterior wall. By incorporating this, charging can be performed not only when the vehicle is stopped but also while it is in motion. The power supply method may be used to transmit and receive power between two vehicles. Solar panels may be installed on the exterior of the vehicle to charge the secondary battery when the vehicle is stopped and when it is in motion. For contactless power supply, electromagnetic induction or magnetic resonance methods can be used. ru.

[0333] Figure 26(B) shows an example of a transport vehicle, a large transport vehicle equipped with an electrically controlled motor. This shows vehicle 2002. The secondary battery module of transport vehicle 2002 has a nominal voltage of, for example, 3. Four rechargeable batteries with a voltage between 0V and 5.0V are used as cell units, and 48 cells are connected in series. The maximum voltage is 70V. The secondary batteries that make up the secondary battery module of battery pack 2201. Aside from differences in the number of elements, it has the same functions as Figure 26(A), so the explanation will be omitted.

[0334] Figure 26(C) shows, as an example, a large transport vehicle 2003 equipped with an electrically controlled motor. This indicates that the secondary battery module of the transport vehicle 2003 has a nominal voltage of, for example, 3.0V or higher. The maximum voltage will be 600V, achieved by connecting more than 100 rechargeable batteries with a voltage of 5.0V or less in series. By using a secondary battery in which the positive electrode active material 100 described in the form is used as the positive electrode, the rate characteristics And it is possible to manufacture secondary batteries with good charge-discharge cycle characteristics for transport vehicles 2003 This can contribute to improved performance and longer lifespan. Also, the secondary battery of battery pack 2202 Aside from differences in the number of secondary batteries that make up the module, it has the same functions as Figure 26(A). Therefore, I will omit the explanation.

[0335] Figure 26(D) shows, as an example, aircraft 2004 having a fuel-burning engine. The aircraft 2004 shown in Figure 26(D) has landing gear for takeoff and landing, so it is a transport vehicle. It can be said that it is part of a secondary battery module, which is constructed by connecting multiple secondary batteries. It has a battery pack 2203 that includes a joule and a charge control device.

[0336] The secondary battery module of the aircraft 2004 uses, for example, eight 4V secondary batteries connected in series. The maximum voltage is 2V. The secondary batteries that make up the secondary battery module of the battery pack 2203 Aside from differences in the number of elements, it has the same functions as Figure 26(A), so the explanation will be omitted.

[0337] The contents of this embodiment can be appropriately combined with the contents of other embodiments.

[0338] (Embodiment 7) In this embodiment, Figure 27 shows an example of implementing a secondary battery, which is one aspect of the present invention, in a building. This will be explained using (A) and Figure 27(B).

[0339] The house shown in Figure 27(A) is an energy storage device 2612 having a secondary battery, which is one embodiment of the present invention. The solar panel 2610 is included. The energy storage device 2612 is connected to the solar panel 2610. They are electrically connected via wire 2611, etc. Also, the energy storage device 2612 and the ground-mounted charging The electrical device 2604 may be electrically connected. The power obtained from the solar panel 2610 is The power stored in the power storage device 2612 can be charged. The secondary battery of the vehicle 2603 can be charged via the charging device 2604. The electrical device 2612 is preferably installed in the underfloor space. This allows for effective use of the space above the floor. Alternatively, the energy storage device 2612 is located on the floor. It can also be installed on top.

[0340] The electricity stored in the energy storage device 2612 can also be used to power other electronic devices in the house. Yes, it is possible. Therefore, even when power cannot be supplied from the commercial power source due to a power outage, the present invention By using a power storage device 2612 according to one embodiment as an uninterruptible power supply, the use of electronic devices becomes possible. It becomes Noh.

[0341] Figure 27(B) shows an example of an energy storage device according to one aspect of the present invention. In the underfloor space 796 of the building 799, an energy storage device 791 according to one aspect of the present invention is installed. Furthermore, the power storage device 791 may be provided with the control circuit described in Embodiment 5. A secondary battery using the positive electrode active material 100 obtained in the embodiment described above as the positive electrode is connected to an energy storage device 791. By using this method, a long-life energy storage device 791 can be created.

[0342] The energy storage device 791 is equipped with a control device 790, and the control device 790 is connected by wiring. And, the distribution board 703, the energy storage controller 705 (also called the control device), and the display unit 706 It is electrically connected to router 709.

[0343] Power is supplied from the commercial power supply 701 to the distribution panel 703 via the service drop connection section 710. Furthermore, power is supplied to the distribution board 703 from the energy storage device 791 and the commercial power supply 701. The distribution board 703 distributes the power received to the general load 707 and via outlets (not shown). It supplies power to the energy storage system load 708.

[0344] General load 707 is electrical equipment such as televisions and personal computers. The energy storage system load 708 is, for example, an electrical appliance such as a microwave oven, refrigerator, or air conditioner.

[0345] The energy storage controller 705 includes a measurement unit 711, a prediction unit 712, and a planning unit 713. The measurement unit 711 measures the general load 707 and the energy storage system during a day (for example, from 0:00 to 24:00). It has a function to measure the amount of electricity consumed by the load 708. In addition, the measuring unit 711 is a power storage device It has the function of measuring the amount of electricity from the 791 unit and the amount of electricity supplied from the commercial power supply 701. It may also be necessary to predict the general load 707 and the energy storage system load 708 during the day. Based on the amount of electricity consumed, during the following day, the general load 707 and the energy storage system load 708 It has a function to predict the amount of electricity demanded to be consumed. In addition, the planning unit 713 has a function to predict the amount of electricity demanded to be consumed. It has the function of planning the charging and discharging of the energy storage device 791 based on the predicted amount of electricity demand.

[0346] The power consumed by the general load 707 and the energy storage system load 708 as measured by the measurement unit 711 The quantity can be checked by the display unit 706. Also, via the router 709, tele This can also be confirmed in electrical equipment such as computers and personal computers. Furthermore, via router 709, mobile electronic devices such as smartphones and tablets can access the network. It can also be confirmed by display unit 706, electrical equipment, and portable electronic terminals. Also, check the predicted electricity demand for each time period (or hourly) as predicted by the measurement unit 712. It is possible.

[0347] The contents of this embodiment can be appropriately combined with the contents of other embodiments.

[0348] (Embodiment 8) This embodiment shows an example of mounting an energy storage device according to one aspect of the present invention on a motorcycle or bicycle. .

[0349] Figure 28(A) shows an example of an electric bicycle using a power storage device according to one embodiment of the present invention. An energy storage device according to one embodiment of the present invention can be applied to the electric bicycle 8700 shown in 28(A). One embodiment of the present invention is a power storage device that includes, for example, a plurality of storage batteries and a protection circuit.

[0350] The electric bicycle 8700 is equipped with a power storage device 8702. The power storage device 8702 provides the rider with an assist It can supply electricity to the motor that is being struck. Also, the energy storage device 8702 is portable. Figure 28(B) shows the device after it has been removed from the bicycle. Also, the energy storage device 8702 The energy storage device according to one aspect of the present invention has multiple storage batteries 8701 built in, and the battery The battery level and other information can be displayed on the display unit 8703. A control circuit 870 capable of controlling the charging of a secondary battery or detecting abnormalities is shown as an example in Embodiment 5. It has 4. The control circuit 8704 is electrically connected to the positive and negative terminals of the storage battery 8701. It is present. In addition, the control circuit 8704 has a small solid secondary as shown in Figures 24(A) and 24(B). A battery may be provided. Control the small solid-state rechargeable battery shown in Figures 24(A) and 24(B). By providing this in circuit 8704, the data in the memory circuit of the control circuit 8704 can be retained for a long time. It can also supply power for this purpose. Furthermore, the positive electrode active material obtained in the above embodiment By combining it with a secondary battery that uses 100 as the positive electrode, a synergistic effect on safety can be obtained. A secondary battery and control circuit using the positive electrode active material 100 obtained in the above-described embodiment as the positive electrode. The 8704 can make a significant contribution to eliminating accidents such as fires caused by secondary batteries.

[0351] Furthermore, Figure 28(C) shows an example of a motorcycle using an energy storage device according to one embodiment of the present invention. Figure 28 The electric motorcycle 8600 shown in (C) includes a power storage device 8602, side mirrors 8601, and a directional indicator. It is equipped with an indicator light 8603. The energy storage device 8602 supplies electricity to the turn signal light 8603. This can be done. Furthermore, a secondary battery can be made using the positive electrode active material 100 obtained in the above embodiment as the positive electrode. The energy storage device 8602, which houses multiple such devices, can have a high capacity and contribute to miniaturization. can.

[0352] Furthermore, the electric motorcycle 8600 shown in Figure 28(C) has a power storage device 86 in the under-seat storage compartment 8604. 02 can be stored. The power storage device 8602 is small and the under-seat storage 8604 is small. It can also be stored in the under-seat storage compartment 8604.

[0353] The contents of this embodiment can be appropriately combined with the contents of other embodiments.

[0354] (Embodiment 9) This embodiment describes an example in which a secondary battery, which is one aspect of the present invention, is mounted in an electronic device. To do so. Electronic devices that implement secondary batteries include, for example, television equipment (television, or television). (also called a revision receiver), monitors for computers, digital cameras, digital Video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices) ), portable game consoles, personal digital assistants, sound playback devices, large game machines such as pachinko machines, etc. Examples include notebook personal computers and tablet devices. These include e-readers and mobile phones.

[0355] Figure 29(A) shows an example of a mobile phone. The mobile phone 2100 has a housing 2101 In addition to the display unit 2102 incorporated into it, there are operation buttons 2103, an external connection port 2104, and It is equipped with a speaker 2105, a microphone 2106, etc. Note that the mobile phone 2100 is secondary It has a battery 2107. The positive electrode active material 100 described in the above embodiment is used as the positive electrode. By incorporating the 2107 secondary battery, high capacity can be achieved, and space saving is achieved through the miniaturization of the casing. This allows for a configuration that can accommodate systemization.

[0356] The 2100 mobile phone offers mobile phone calls, email, document viewing and creation, music playback, and internet connectivity. It can run various applications such as internet communication and computer games. .

[0357] The operation button 2103 is used for setting the time, as well as turning the power on and off, and turning wireless communication on and off. It has various functions such as operation, silent mode activation and deactivation, and power saving mode activation and deactivation. This can be done. For example, the operating system built into the mobile phone 2100 The system also allows you to freely configure the function of the operation button 2103.

[0358] Furthermore, the mobile phone 2100 is capable of performing standardized short-range wireless communication. For example, by communicating with a wireless headset, hands-free communication is possible. They can also talk.

[0359] Furthermore, the mobile phone 2100 is equipped with an external connection port 2104, and has a connector for connecting to other information terminals. Data can be exchanged directly via this. Also, via external connection port 2104 It can also be charged. Note that charging is performed wirelessly without using the external connection port 2104. This may also be done by means of.

[0360] The mobile phone 2100 preferably has a sensor. For example, a fingerprint sensor. Human body sensors such as pulse sensors and body temperature sensors, touch sensors, pressure sensors, acceleration sensors, It is preferable that such features be installed.

[0361] Figure 29(B) shows an unmanned aerial vehicle 2300 having multiple rotors 2302. The 2300 is sometimes called a drone. The unmanned aerial vehicle 2300 is one aspect of the present invention. It has a secondary battery 2301, a camera 2303, and an antenna (not shown). Unmanned aerial vehicle The device 2300 can be remotely controlled via an antenna. Secondary batteries using positive electrode active material 100 as the positive electrode have high energy density and high safety. It can be used safely for extended periods of time, and is a rechargeable battery for use in the Unmanned Aerial Vehicle 2300. It is preferable to do so.

[0362] Figure 29(C) shows an example of a robot. The robot 6400 shown in Figure 29(C) is , secondary battery 6409, illuminance sensor 6401, microphone 6402, upper camera 640 3. Speaker 6404, display unit 6405, lower camera 6406, and obstacle sensor 640 7. It is equipped with a moving mechanism 6408, a computing device, etc.

[0363] Microphone 6402 has the function of detecting the user's voice and ambient sounds, etc. Speaker 6404 has the function of emitting sound. Robot 6400 has a microphone Using the 6402 and speaker 6404, communication with the user is possible. It is possible.

[0364] The display unit 6405 has the function of displaying various information. The robot 6400 is used by The desired information can be displayed on the display unit 6405. The display unit 6405 is touch It may also be equipped with a panel. Furthermore, the display unit 6405 is a detachable information terminal. It is also possible to install it in a fixed position on the robot 6400 for charging and data transfer. Make it possible.

[0365] The upper camera 6403 and lower camera 6406 are used to image the area around the robot 6400. It has the ability to move the robot 6407 using the moving mechanism 6408. Robot 64 can detect the presence or absence of obstacles in the direction of travel as it moves forward. 00 uses the upper camera 6403, the lower camera 6406, and the obstacle sensor 6407 It can perceive its surroundings and move safely.

[0366] The robot 6400 has a secondary battery 6409 according to one aspect of the present invention and a semiconductor in its internal region. The apparatus or electronic components are provided. The positive electrode active material 100 obtained in the above embodiment is used as the positive electrode. These secondary batteries have high energy density and high safety, making them suitable for long-term, long-term use. It can be used for all purposes and is suitable as a secondary battery 6409 to be installed in the robot 6400.

[0367] Figure 29(D) shows an example of a cleaning robot. The cleaning robot 6300 has a housing 63 01 Display unit 6302 located on the top surface, multiple cameras 6303 located on the side, brush It includes 6304, an operation button 6305, a secondary battery 6306, various sensors, etc. (as shown in the figure) Although not shown, the 6300 cleaning robot is equipped with wheels, a suction nozzle, etc. The robot 6300 moves autonomously, detects the debris 6310, and removes it from the suction port located on its underside. It can suck up dust.

[0368] For example, the cleaning robot 6300 analyzes images captured by the camera 6303 to identify walls, furniture, etc. It can also determine the presence or absence of obstacles such as steps. Furthermore, image analysis can detect wiring, etc. If an object that may become entangled in the brush 6304 is detected, the rotation of the brush 6304 will be stopped. This is possible. The cleaning robot 6300 has a secondary battery 6 according to one aspect of the present invention in its internal region. The positive electrode active material obtained in the above embodiment comprises 306 and a semiconductor device or electronic component. Secondary batteries using 100 as the positive electrode have high energy density and high safety, and can be used for long periods of time. It can be used safely for extended periods, and the rechargeable battery 6306 installed in the cleaning robot 6300 and It is preferable to do so.

[0369] Figure 30(A) shows an example of a wearable device. A wearable device is an electric device. It uses a secondary battery as a power source. Furthermore, when the user uses it in their daily life or outdoors, it is designed to prevent... To enhance splash resistance, water resistance, or dust resistance, the connector portion is exposed. Wearable devices that can be charged wirelessly, in addition to wired charging, are in demand.

[0370] For example, in a spectacle-type device 4000 as shown in Figure 30(A), a secondary [of the present invention] is provided. It can be equipped with a battery. The glasses-type device 4000 consists of frame 4000a and display It has section 4000b. A rechargeable battery is mounted in the temple section of the curved frame 4000a. This results in a lightweight, well-balanced, and long-lasting glasses-type device. It can be set to 4000. The positive electrode active material 100 obtained in the above embodiment is used as the positive electrode. The secondary battery has a high energy density and can accommodate space-saving measures associated with miniaturizing the casing. The configuration can be realized.

[0371] Furthermore, the headset-type device 4001 is equipped with a secondary battery according to one aspect of the present invention. This is possible. The headset-type device 4001 includes at least a microphone unit 4001a and a frame It has a flexible pipe 4001b and an earphone section 4001c. A secondary battery can be provided in 001b or in the earphone section 4001c. A secondary battery using the positive electrode active material 100 obtained in this form as the positive electrode has a high energy density. This allows for a configuration that can accommodate space savings resulting from the miniaturization of the enclosure.

[0372] Furthermore, a secondary battery according to one aspect of the present invention is incorporated into a device 4002 that can be directly attached to the body. It can be mounted. Inside the slim housing 4002a of Device 4002, the secondary battery 400 2b can be provided. The positive electrode active material 100 obtained in the above embodiment is used as the positive electrode. The secondary battery has a high energy density and can accommodate space saving due to the miniaturization of the housing. It is possible to achieve success.

[0373] Furthermore, a secondary battery according to one aspect of the present invention is mounted on a device 4003 that can be attached to clothing. This is possible. Inside the slim housing 4003a of device 4003, the secondary battery 4003b A positive electrode active material 100 obtained in the above embodiment is used as the positive electrode. The next battery has a high energy density and a configuration that can accommodate space saving due to the miniaturization of the housing. It can be achieved.

[0374] Furthermore, a secondary battery according to one aspect of the present invention can be mounted on the belt-type device 4006. The belt-type device 4006 consists of a belt section 4006a and a wireless power supply / receiving section 40 It has 06b, and a secondary battery can be mounted in the internal region of the belt portion 4006a. A secondary battery using the positive electrode active material 100 obtained in the embodiment described above as the positive electrode has a high energy density This allows for a configuration that can accommodate space savings resulting from the miniaturization of the enclosure.

[0375] Furthermore, a secondary battery according to one aspect of the present invention can be mounted in the wristwatch-type device 4005. The wristwatch-type device 4005 has a display unit 4005a and a belt unit 4005b, A secondary battery can be provided in the display section 4005a or the belt section 4005b. A secondary battery using the positive electrode active material 100 obtained in this form as the positive electrode has a high energy density. This allows for a configuration that can accommodate space savings resulting from the miniaturization of the enclosure.

[0376] The display unit 4005a displays not only the time, but also various other information such as incoming emails and phone calls. It is possible.

[0377] Furthermore, the wristwatch-type device 4005 is a wearable device that is worn directly on the wrist. Therefore, sensors may be installed to measure the user's pulse, blood pressure, etc. User's exercise volume It also allows for the accumulation of health-related data and the management of health.

[0378] Figure 30(B) shows a perspective view of the wristwatch-type device 4005 after it has been removed from the arm.

[0379] A side view is also shown in Figure 30(C). Figure 30(C) shows the secondary battery 913 inside the internal region. This shows how it is stored. The secondary battery 913 is the secondary battery shown in Embodiment 3. The secondary battery 913 is located in a position overlapping with the display unit 4005a, and is high density and high capacity. It can be used in small quantities, and is also small and lightweight.

[0380] Since the wristwatch-type device 4005 is required to be small and lightweight, By using the positive electrode active material 100 obtained in the above embodiment as the positive electrode of the secondary battery 913, This allows for a high-energy-density, compact secondary battery 913.

[0381] Figure 30(D) shows an example of wireless earphones. Here, a pair of main units 4100a The diagram shows wireless earphones having the main unit 4100b, but they do not necessarily have to be a pair. good.

[0382] The main units 4100a and 4100b include a driver unit 4101, an antenna 4102, and two It has a battery 4103. It may also have a display unit 4104. It may also have a wireless IC or other circuit. It is preferable that the device has a circuit board on which the device is mounted, charging terminals, etc. It may also have a microphone.

[0383] Case 4110 contains a secondary battery 4111. It also contains circuits such as a wireless IC and a charging control IC. It is preferable that the circuit board has a charging terminal on it, and that it also has a display unit, buttons, etc. That's good too.

[0384] The main units 4100a and 4100b communicate wirelessly with other electronic devices such as smartphones. This allows sound data and other information sent from other electronic devices to be received by the main unit 4100a and It can be played back on the 4100b. Also, the 4100a and 4100b units have microphones. Then, the sound acquired by the microphone is sent to another electronic device, and the sound after processing by that electronic device is... The data can be sent back to the main units 4100a and 4100b for playback. For example, it can also be used as a translation device.

[0385] Furthermore, the secondary battery 4111 in case 4110 is transferred to the secondary battery 4 in main unit 4100a. It is possible to charge 103. Secondary batteries 4111 and 4103 are first Coin-type rechargeable batteries, cylindrical rechargeable batteries, etc., according to the above embodiment can be used. A secondary battery using the positive electrode active material 100 obtained in this form as the positive electrode has a high energy density. By using it in secondary batteries 4103 and 4111, the size of wireless earphones can be reduced. This allows for a configuration that can accommodate the resulting space-saving requirements.

[0386] This embodiment can be implemented in appropriate combination with other embodiments. [Examples]

[0387] In this example, a positive electrode active material according to one embodiment of the present invention was prepared, and its cycle characteristics were evaluated.

[0388] First, the method for preparing the positive electrode active material will be explained with reference to Figures 1 through 8.

[0389] <Sample 1> Nickel source: nickel(II) sulfate, cobalt source: cobalt(II) sulfate, man Using manganese(II) sulfate as the cancer source, Ni:Co:Mn = 8:1:1 (molar ratio) The required amount was weighed and dissolved in water to make a 2M solution. To this, 0.075M of granules was added as a chelating agent. A solution was prepared by adding lysine.

[0390] A 5M sodium hydroxide aqueous solution was used as the alkaline solution.

[0391] A 0.075 M glycine aqueous solution was used as the bracing solution. Nitrogen was added to the bracing solution via a bubble. The nitrogen flow rate was set to 1 L / min.

[0392] The acid solution was added dropwise while the stocking solution was stirred at 1000 rpm. The amount added was 0.40 mL. The flow rate was increased from 0.93 mL / min to 0.93 mL / min. Alkaline solution was added dropwise as needed, and the saturation solution was added. The pH was maintained at 10.3. The temperature of the loading solution was also maintained at 70°C. These coprecipitation reactions For the application, we used OptiMax (manufactured by Mettler-Toledo).

[0393] The precipitate formed by the above coprecipitation reaction is filtered with pure water and acetone, dried, and then a complex hydroxide is obtained. I obtained it.

[0394] Lithium hydroxide monohydrate is used as the lithium source and mixed with the composite hydroxide obtained above. The mixing ratio was such that when the sum of nickel, cobalt, and manganese was considered to be 1, lithium was added at a ratio of 1.01 (m (Ratio)

[0395] The above mixture was heated in an aluminum oxide crucible at 500°C for 10 hours in an oxygen atmosphere. It was heated in a muffle furnace. The oxygen flow rate was 5 L / min. It was cooled to room temperature, crushed, and compounded. An oxide was obtained.

[0396] The composite oxide obtained above was similarly heated at 800°C for 10 hours. A comparative example prepared without using [the specified method] was designated as Sample 1.

[0397] <Sample 2> In Sample 2, gallium was added in step S12. Specifically, sulfur was used as the gallium source. Using gallium(III) acid, the molar ratio is Ni:Co:Mn:Ga = 80:10:9:1. The required amount was weighed, dissolved in water to make a 2M solution, and glycine was added to prepare an acid solution. The mixing rate of the solution was increased from 0.20 mL / min to 0.47 mL / min. It was prepared in the same manner as in 1. That is, a lithium source was added and heated at 500°C for 10 hours, then 8 It was heated at 0°C for 10 hours.

[0398] <Sample 3> In Sample 3, the same composite hydroxide as in Sample 1 was used, and gallium was added in step S41. Specifically, gallium oxyhydroxide was used as the gallium source, along with the lithium source. It was mixed with a composite hydroxide prepared in the same manner as Sample 1. The mixing ratio was nickel, cobalt, and When the sum of gannes was set to 1, the amount of gallium was set to 0.01 (molar ratio). Other settings were the same as in Sample 1. It was prepared as follows: a lithium source and a gallium source were added and heated at 500°C for 10 hours, It was heated at 800°C for 10 hours.

[0399] <Sample 4> In Sample 4, the same composite hydroxide as in Sample 1 was used, and gallium was added in step S61. Specifically, gallium oxyhydroxide was used as the gallium source, and the same procedure as in Sample 1 was followed. The prepared composite oxide was mixed with the prepared material. The mixing ratio was such that the sum of nickel, cobalt, and manganese was 1. At this time, the gallium was used at a molar ratio of 0.01. Specifically, a lithium source was added and the mixture was heated at 500°C. After heating for 10 hours, it was heated at 800°C for another 10 hours. A gallium source was then added and the temperature was increased to 800°C. It was heated for 2 hours. Otherwise, it was prepared in the same way as Sample 1.

[0400] <Sample 11> Sample 11 was prepared in the same manner as Sample 1.

[0401] <Sample 12> In Sample 12, aluminum was added in step S12. Specifically, aluminum Using aluminum sulfate as the source, Ni:Co:Mn:Al=79:10:10:1( Weigh the amount to the required ratio, dissolve it in water to make a 2M solution, add glycine, and prepare an acid solution. The acid solution was added at a rate of 0.8 L / min. The rest of the preparation was the same as for Sample 2.

[0402] <Sample 13> In Sample 13, the same composite hydroxide as in Sample 11 was used, and aluminum was subjected to step S It was added at step 41. Specifically, aluminum hydroxide was used as the aluminum source, and lithium Along with the source, it was mixed with a composite hydroxide prepared in the same manner as in Sample 1. The mixing ratio was nickel, co When the sum of balt and manganese is set to 1, aluminum is set to 0.01 (molar ratio). Others are... It was made in the same way as Sample 3.

[0403] <Sample 14> In Sample 14, the same composite hydroxide as in Sample 11 was used, and aluminum was subjected to step S It was added at 61. Specifically, aluminum hydroxide was used as the aluminum source, and the sample It was mixed with a composite oxide prepared in the same manner as in 1. The mixing ratio was the sum of nickel, cobalt, and manganese. When the ratio of aluminum to ions was set to 1, the amount of aluminum was set to 0.01 (molar ratio). The rest of the preparation was the same as for Sample 4. did.

[0404] Table 4 shows the preparation conditions for Samples 1 through 4 and Samples 11 through 14. .

[0405] [Table 4]

[0406] <sem> The SEM image of sample 1 is shown in Figure 31(A), sample 2 in Figure 31(B), and sample 3 in Figure 31(B). Sample 4 is shown in Figure 32(B) in 32(A). The positive electrode active material was in the form of secondary particles. Ta.

[0407] <Cycle Characteristics> Using the positive electrode active material prepared above, a half-cell was assembled as follows.

[0408] Prepare acetylene black (AB) as the conductive material and polyvinylidene fluoride (PVD) as the binder. F) was prepared. The positive electrode active material was mixed in the ratio AB:PVDF = 95:3:2 (by weight) and then slid A slurry was prepared and coated onto an aluminum current collector. N was used as the solvent for the slurry. MP (N-methyl-2-pyrrolidone) was used.

[0409] After coating the current collector with slurry, the solvent was evaporated and it was pressed. Through the above process, the positive electrode was formed. The amount of active material loaded on the positive electrode was approximately 7 mg / cm³. 2 That's what I decided.

[0410] The electrolyte consists of ethylene carbonate (EC) and diethyl carbonate (DEC) at EC: A mixture of DEC = 3:7 (by volume) with vinylene carbonate (VC) added as an additive. A solution containing 2 wt% of ) was used, and the electrolyte in the electrolyte solution contained 1 mol / L of hexafluoride. Lithium phosphate (LiPF6) was used. Polypropylene was used as the separator.

[0411] A lithium metal is prepared as the counter electrode, and a coin-shaped half-cell equipped with the above-mentioned positive electrode, etc., is formed. The charge-discharge cycle characteristics were measured.

[0412] Charging is CC / CV (100mA / g, 4.5V, 10mA / g cut), discharging is CC ( The settings were set to 100mA / g, 2.7V cut. A 10-minute pause was taken between charging and discharging. The measurement temperature was set at 45°C.

[0413] The discharge capacities of Samples 1 through 4 are shown in Figure 33(A), and the discharge capacity retention rates are shown in Figure 33(B). The discharge capacities of samples 11 to 14 are shown in Figure 34(A), and the discharge capacity maintenance is shown. The rate is shown in Figure 34(B). The maximum discharge capacity is also shown in Table 4.

[0414] As shown in Figures 33 and 34, despite the relatively high measurement temperature of 45°C, Sun Pulls 2 through 4 and samples 12 through 14 showed good cycle characteristics. In particular, the sample in which the added elements were mixed in step S61 showed the best discharge capacity maintenance rate. The results were good. The discharge capacity retention rate after 50 cycles was 94.6% for sample 4, and for sample 4, The percentage for 14 was 94.0%. [Explanation of Symbols]

[0415] 98. Complex Hydroxides 99. Composite Oxides 100 Cathode active material 104 Tetrahedron Site 108 Octahedron Site 110 Replacement locations 170 Co-precipitation method synthesis equipment 171 Reaction vessel 172 Stirring section 173 Stirring motor 174 Thermometer 175 tank 176 tube 177 Pumps 180 tanks 181 tube 182 pump 186 Tank 187 tube 188 pumps 190 Control device 191 Reflux condenser 192 Water< / sem>

Claims

1. A composite hydroxide containing nickel, cobalt, and manganese is formed by reacting an aqueous solution containing nickel, cobalt, and manganese with an alkaline solution. The composite hydroxide is mixed with a lithium source, and a first heating is performed to form a composite oxide. A method for producing a positive electrode active material, comprising mixing the aforementioned composite oxide with a first additive element source and performing a second heating, The first heating atmosphere and the second heating atmosphere are atmospheres containing oxygen with a dew point of -50°C or lower. The first additive element source has a first additive element, A method for producing a positive electrode active material, wherein the first additive element is at least one selected from calcium, gallium, boron, aluminum, indium, magnesium, and fluorine.

2. In claim 1, A method for producing a cathode active material, wherein the first additive element is gallium.

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