JP2012094350A - Positive electrode plate for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery, method of manufacturing positive electrode plate for nonaqueous electrolyte secondary battery, and battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive electrode plate for a nonaqueous electrolyte secondary battery which is superior in output/input characteristics and can satisfy demand for charging/discharging acceleration even when an active material of high capacity is used, to provide the nonaqueous electrolyte secondary battery, to provide a method of manufacturing such a positive electrode plate, and to provide a battery pack equipped with such the nonaqueous electrolyte secondary battery.SOLUTION: The positive electrode plate for the nonaqueous electrolyte secondary battery includes a current collector, and the electrode active material layer formed on at least a part of the surface of the current collector. The electrode active material layer is constituted of a first electrode active material particle and a second electrode active material. The first electrode active material particles and the current collector, and mutual electrode active material particles are fixed and adhered by the second electrode active material. This second electrode active material has larger lattice constant than the first electrode active material particle.

Description

  The present invention relates to a positive electrode plate used for a non-aqueous electrolyte secondary battery, a non-aqueous electrolyte secondary battery, a method for producing a positive electrode plate for a non-aqueous electrolyte secondary battery, and a battery pack.

  A non-aqueous electrolyte secondary battery represented by a lithium ion secondary battery has a high energy density and a high voltage, and is gradually charged when the battery is charged before being completely discharged, which is called a memory effect at the time of charge / discharge. Since there is no phenomenon in which the battery capacity decreases, it is used in various fields such as portable devices, notebook computers, and portable devices.

Currently, as a measure to prevent global warming, efforts to reduce CO ₂ emissions are being carried out on a global scale. By reducing the dependence on oil and allowing it to travel with a low environmental load, it can greatly reduce CO ₂ emissions. There is an urgent need to develop and promote next-generation clean energy vehicles represented by plug-in hybrid vehicles and electric vehicles that can contribute. If non-aqueous electrolyte secondary batteries can be used as the driving force for these next-generation clean energy vehicles, there is no need to rely on gasoline, which can greatly contribute to CO ₂ reduction and greatly prevent global warming. Can contribute. On the other hand, in order to use a nonaqueous electrolyte secondary battery as a driving force for a next-generation clean energy vehicle, output characteristics similar to gasoline are required.

  Currently, various proposals of non-aqueous electrolyte secondary batteries include a positive electrode plate, a negative electrode plate, a separator, and a non-aqueous electrolyte solution. The positive electrode plate is generally provided with an electrode active material layer in which positive electrode active material particles are fixed to the surface of a current collector such as a metal foil. Moreover, as a negative electrode plate, what is equipped with the electrode active material layer by which a negative electrode active material particle adheres to the collector surface, such as copper and aluminum, is common.

  In order to produce the electrode plate which is the positive electrode plate or the negative electrode plate, first, the electrode active material particles which are the positive electrode active material particles or the negative electrode active material particles, the resin binder, or further, a conductive agent or other as required The material is kneaded and / or dispersed in a solvent to prepare a slurry-like electrode active material layer forming liquid. And an electrode plate provided with an electrode active material layer is formed by applying an electrode active material layer forming liquid on the current collector surface, then drying to form a coating film on the current collector, and pressing (for example, Patent Document 1 or Patent Document 2).

  At this time, the electrode active material particles contained in the electrode active material layer forming liquid are particulate metal compounds dispersed in the liquid, and as such, are applied to the surface of the current collector, dried, and pressed. Even if it is done, it will be hard to adhere to the surface of the current collector, and will peel off from the current collector immediately. Therefore, when forming the electrode active material layer, a resin binder is added to the electrode active material layer forming liquid, and the electrode active material particles are fixed on the current collector by the resin binder, and the electrode active material particles They are stuck together.

JP 2006-310010 A JP 2006-107750 A

  However, when the electrode active material layer is formed by the method proposed in Patent Document 1 and Patent Document 2, the impedance is lowered to a level that can satisfy the requirements in the field where high input / output characteristics are required. I can't. In recent years, there has been a demand for higher capacity for non-aqueous electrolyte secondary batteries, while there is also a request for faster charge / discharge. However, when a high-capacity active material is used, it is not possible to meet the demand for high-speed charge / discharge. On the other hand, when an active material capable of high-speed charge / discharge is used, a high-capacity request is required. I can't meet. In other words, it is common to think that there is a so-called trade-off between increasing capacity and increasing charge / discharge, and sufficiently satisfy the demand for increasing charge / discharge speed using a high-capacity active material. Was difficult.

  The present invention has been made in view of such a situation. In the positive electrode plate for a non-aqueous electrolyte secondary battery, the non-aqueous electrolysis can satisfy the demand for speeding up charging and discharging while being excellent in input / output characteristics. The positive electrode plate for a liquid secondary battery, and more specifically, the positive electrode plate for a non-aqueous electrolyte secondary battery that can satisfy the demand for high-speed charge / discharge even when a high-capacity active material is used. It aims at providing a nonaqueous electrolyte secondary battery provided with the positive electrode plate for water electrolyte secondary batteries, a method of manufacturing such a positive electrode plate, and a battery pack provided with such a nonaqueous electrolyte secondary battery.

  The present invention for solving the above problems is a positive electrode plate for a non-aqueous electrolyte secondary battery comprising a current collector and an electrode active material layer formed on at least a part of the surface of the current collector. The electrode active material layer contains first electrode active material particles and a second electrode active material, and the first electrode active material particles, the current collector, and the first electrode The active material particles are fixed to each other by the second electrode active material, and a lattice constant of the second electrode active material is larger than that of the first electrode active material particles.

  Further, the second electrode active material may be a lithium composite oxide.

  The second electrode active material may be a composite oxide of lithium and at least one metal selected from cobalt, nickel, manganese, iron, and titanium.

  Moreover, the said electrode active material layer may contain the location connected by continuing a crystal lattice in some adjacent 2nd electrode active materials.

  Moreover, this invention for solving the said subject is a non-aqueous electrolyte provided with the positive electrode plate, the negative electrode plate, the separator provided between the said positive electrode plate and the said negative electrode plate, and a non-aqueous electrolyte at least. A secondary battery, wherein the positive electrode plate is a positive electrode plate for a non-aqueous electrolyte secondary battery having the above characteristics.

  In addition, the method of the present invention for solving the above-described problems includes electrode active material particles and one or more metals that are heated to become an electrode active material having a lattice constant larger than that of the electrode active material particles. An electrode active material layer-forming liquid containing an element-containing compound, and a coating step for coating the at least part of the current collector to form a coating film; and And a heating step of heating at a temperature equal to or higher than a temperature to be an electrode active material.

  In addition, as the metal element-containing compound, one or more metal salts containing a metal selected from cobalt, nickel, manganese, iron, and titanium, and a lithium salt may be used.

  Further, the present invention for solving the above-described problems includes at least a storage case, a nonaqueous electrolyte secondary battery including a positive electrode terminal and a negative electrode terminal, and a protection circuit having an overcharge and overdischarge protection function, A battery pack in which the non-aqueous electrolyte secondary battery and the protection circuit are housed in a storage case, wherein the non-aqueous electrolyte secondary battery has the above characteristics. It is characterized by being.

  The positive electrode plate for a non-aqueous electrolyte secondary battery according to the present invention (hereinafter, also simply referred to as “positive electrode plate”) includes a first electrode active material particle, a current collector, and a first electrode active material particle. The two electrode active materials are fixed. Thereby, the impedance of a positive electrode plate can be reduced and input / output characteristics can be improved. Furthermore, in addition to the above-described effects, the second electrode active material has a larger lattice constant than the first electrode active material particles. It is possible to take in and out the alkali metal ions present in the substrate at high speed, and thus contribute to speeding up charging and discharging in the entire positive electrode plate. As a result, the demand for speeding up of charge / discharge that cannot be supplemented by the first electrode active material particles can be supplemented by the second electrode active material, and high capacity active material particles can be used as the first electrode active material particles. Even when it is used, it is possible to sufficiently satisfy the demand for speeding up of charging and discharging.

  Moreover, according to the non-aqueous electrolyte secondary battery of the present invention including the positive electrode plate for a non-aqueous electrolyte secondary battery, it is possible to sufficiently satisfy the demand for speeding up charging and discharging.

  Further, according to the method for producing a positive electrode plate for a non-aqueous electrolyte secondary battery of the present invention (hereinafter, also simply referred to as “the production method of the present invention”), the above-described effects can be achieved with an easy method and a general-purpose material. The positive electrode plate for nonaqueous electrolyte secondary batteries which has can be manufactured.

  Moreover, according to the battery pack of this invention, the request | requirement with respect to the speed-up of charging / discharging can fully be satisfy | filled.

It is sectional drawing of the positive electrode plate for nonaqueous electrolyte secondary batteries of this invention. It is a conceptual diagram for demonstrating the state of the 1st electrode active material particle and the 2nd electrode active material of the positive electrode plate for nonaqueous electrolyte secondary batteries of this invention at the time of charge. It is a cyclic voltammogram which shows the result of the cyclic voltammetry test using the metal oxide which shows alkali metal ion insertion elimination reaction. It is a cyclic voltammogram which shows the result of the cyclic voltammetry test using the metal oxide which does not show alkali metal ion insertion elimination reaction. It is the schematic which shows an example of the nonaqueous electrolyte secondary battery of this invention. It is a sectional exploded view showing an example of a battery pack of the present invention.

  Hereinafter, the positive electrode plate for a non-aqueous electrolyte secondary battery of the present invention will be specifically described with reference to FIGS. 1A and 1B are sectional views of a positive electrode plate for a non-aqueous electrolyte secondary battery of the present invention. In the following description, a lithium ion secondary battery will be described as an example of the non-aqueous electrolyte secondary battery of the present invention unless otherwise specified.

(Positive electrode plate for non-aqueous electrolyte secondary battery)
As shown in FIGS. 1 (a) and 1 (b), a positive electrode plate 10 for a non-aqueous electrolyte secondary battery of the present invention includes a current collector 1 and electrodes formed on at least a part of the surface of the current collector. The electrode active material layer 2 includes first electrode active material particles 21 and a second electrode active material 22.

(Current collector)
The current collector 1 used in the present invention is not particularly limited as long as it is generally used as a current collector for a positive electrode plate for a nonaqueous electrolyte secondary battery. For example, a current collector formed of a simple substance such as an aluminum foil or a nickel foil or an alloy can be preferably used. The current collector 1 used in the present invention is a current collector that has been subjected to surface processing on the surface on which the electrode active material layer 2 is scheduled to be formed (the surface of the current collector) as necessary. Also good. As the current collector 1 whose surface is processed on its surface, a current collector in which a conductive material is laminated on the surface of a material having a current collecting function, chemical polishing treatment, corona treatment, and oxygen plasma treatment were performed. Examples include current collectors. That is, the current collector 1 of the present invention is not only a current collector formed of only a material having a current collecting function, but also a surface in which a substance for ensuring conductivity is laminated, or some surface treatment Also included are those made. The surface of the current collector in the present invention means the surface of a material having a current collecting function in the current collector 1 formed only from a material having a current collecting function, and has a current collecting function. In the case where surface processing or a conductive material is laminated on the entire surface of the material, the surface processing surface or the surface of the conductive material is referred to. In addition, in the case where a part of the surface of the material having a current collecting function is subjected to a surface processing treatment or a conductive material, the surface processing surface, the surface of the conductive material, or these surfaces A portion where a processing treatment or a conductive substance is not stacked (that is, a surface of a material having a current collecting function).

  Although the thickness of the electrical power collector 1 will not be specifically limited if it is the thickness which can generally be used as an electrical power collector of the positive electrode plate for nonaqueous electrolyte secondary batteries, It is preferable that it is 10-100 micrometers, and is 15-50 micrometers. It is more preferable.

(Electrode active material layer)
The electrode active material layer 2 in the present invention is a first electrode active material particle 21, a current collector 1, a first electrode active material particle 21, and a first electrode for fixing the first electrode active material particles 21 to each other. 2 electrode active materials 22.

  The layer thickness of the electrode active material layer 2 is not particularly limited, and can be appropriately designed in consideration of electric capacity and input / output characteristics required for the positive electrode plate, and is generally about 300 nm to 200 μm. In particular, according to the present invention, the presence of the second electrode active material can meet the demand for higher capacity without increasing the thickness of the electrode active material layer 2, and the electrode active material layer 2 can be made thinner. It is also possible to do.

  In addition, the electrode active material layer 2 preferably has voids so that the electrolytic solution can permeate, and the porosity is preferably 10% or more and 70% or less.

  Below, the substance contained in the electrode active material layer 2 in this invention is demonstrated concretely.

<First electrode active material particles>
As the 1st electrode active material particle 21 contained in the electrode active material layer 2 in this invention, if it is the electrode active material particle which can generally be used in the positive electrode plate for nonaqueous electrolyte secondary batteries, it is a chargeable / dischargeable electrode active material particle. There is no particular limitation. For example, specific examples of the first electrode active material particles 21 in the lithium ion secondary battery include LiCoO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , LiFeO ₂ , Li ₄ Ti ₅ O ₁₂ , LiFePO ₄ , LiNi. Examples thereof include electrode active material particles such as lithium transition metal composite oxides such as _1/3 Mn _1/3 Co _1/3 O ₂ and LiNi _0.80 Co _0.15 Al _0.05 O ₂ . Specific examples of the first electrode active material particles 21 in the sodium ion secondary battery include electrode active material particles such as NaCoO ₂ , NaNi _0.3 Mn _0.7 O ₂ , and NaNi _0.1 Cr _0.9 O _2. Can do.

The first electrode active material particles 21 may satisfy at least the condition that the lattice constant is smaller than the lattice constant of the second electrode active material 22, and the first electrode active material particles 21 do not necessarily have a high capacity. It is not necessary to be an active material that can satisfy the demand for chemical conversion. In the present invention, the second electrode active material 22 is intended to compensate for the demand for higher charge / discharge speed that cannot be compensated by the first electrode active material particles. From this point of view, it is preferable to select an active material having a high capacity for the first electrode active material particles 21, and among the materials listed above, LiNi _1/3 Mn _1/3 Co _{1 / 3} O ₂ and LiNi _0.80 Co _0.15 Al _0.05 O ₂ are preferred. In the present invention, when an active material capable of satisfying the demand for higher capacity is used as the first electrode active material particles, not only the demand for higher charge / discharge speed but also the demand for higher capacity. Can be satisfied.

  In this specification, “capacity” refers to the theoretical capacity (mAh / g) of the electrode active material. “Theoretical capacity”: The unit (mAh / g) is a capacity calculated as a result of all alkali metal ions contributing to the elimination reaction in the alkali metal ion insertion and elimination reaction. The capacity is calculated by dividing the amount by the molecular weight of the second electrode active material 22. That is, the theoretical capacity can be uniquely determined if the composition of the electrode active material forming the electrode active material layer is known.

Hereinafter, the calculation method of the theoretical capacity will be specifically described by taking LiCoO ₂ as an example. The reaction formula of LiCoO ₂ is represented by the following (formula 1). If all lithium contributes to the elimination reaction, X = 1.

Since the Coulomb amount (A · sec) is a product of the lithium ion reaction amount and the Faraday constant (9.65 × 10 ⁴ (C)), the lithium ion reaction amount (1 (mol)) × Faraday constant (9 .65 × 10 ⁴ (C)) = 9.65 × 10 ⁴ (C) = 9.65 × 10 ⁴ (A · sec) = 2.68 × 10 ⁴ (mA · h). Then, the theoretical capacity (274 (mAh / g)) of LiCoO ₂ is calculated by dividing this Coulomb amount by the molecular weight of LiCoO ₂ (97.87 g) (2.68 × 10 ⁴ /97.87). The That is, the theoretical capacity of LiCoO ₂ is 274 (mAh / g).

The theoretical capacities of other electrode active materials can be calculated in the same manner, and the theoretical capacities of main electrode active materials are as follows.
LiMn ₂ O ₄ 148 (mAh / g)
LiCoO ₂ 274 (mAh / g)
LiNiO ₂ ... 275 (mAh / g)
LiNi _0.9 Co _0.1 O ₂ ... 275 (mAh / g)
LiNi _1/3 Mn _1/3 Co _1/3 O ₂ ... 278 (mAh / g)
LiNi _0.80 Co _0.15 Al _0.05 O ₂ ... 278.93 (mAh / g)

  The particle diameter of the 1st electrode active material particle 21 used for this invention is not specifically limited, The thing of arbitrary magnitude | sizes can be selected suitably, and can be used.

  The particle diameter of the first electrode active material particles 21 shown in the present invention and the present specification is an average particle diameter (volume median particle diameter: D50) measured by laser diffraction / scattering particle size distribution measurement. In addition, the particle diameter of the first electrode active material particles 21 contained in the electrode active material layer is determined by identifying the measured electron microscope observation data using a particle recognition tool and recognizing the recognized particle image. The particle size distribution graph can be created based on the shape data acquired from the above and calculated from the particle size distribution graph. The particle size distribution graph can be created, for example, by using an image analysis type particle size distribution measurement software (manufactured by Mount Tech Co., Ltd., MAC VIEW) based on an electron microscope observation result.

<Second electrode active material>
As shown in FIGS. 1A and 1B, the electrode active material layer 2 constituting the positive electrode plate 10 of the present invention has a function as an active material, a current collector 1 and a first electrode active material. The second electrode active material 22 that also functions as a binding material for fixing the particles 21 and the first electrode active material particles to each other is contained, and the lattice constant of the second electrode active material 22 is The first electrode active material particle 21 has a lattice constant larger than that of the first electrode active material particle 21.

The second electrode active material 22 has a function of fixing the current collector 1, the first electrode active material particles 21, and the first electrode active material particles 21, and the first electrode active material particles 21. As long as the condition that the lattice constant is larger than that of the positive electrode plate for a nonaqueous electrolyte secondary battery, a chargeable / dischargeable electrode active material generally used can be used. For example, specific examples of the second electrode active material 22 when the non-aqueous electrolyte secondary battery is a lithium ion secondary battery include LiCoO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , LiFeO ₂ , Li _4. Examples include lithium transition metal composite oxides such as Ti ₅ O ₁₂ , LiFePO ₄ , LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , LiNi _0.9 Co _0.1 O ₂ , LiNi _0.80 Co _0.15 Al _0.05 O ₂ . be able to. The present invention is based on the condition that the second electrode active material 22 is an electrode active material having a lattice constant larger than that of at least the first electrode active material particles 21. The second electrode active material 22 that can be used differs depending on the electrode active material particles 21.

  According to the second electrode active material 22 that also functions as a so-called binding material of the present invention, the input / output characteristics can be improved. Moreover, since the second electrode active material 22 has a function as an electrode active material, like the first electrode active material particles 21, the presence of the second electrode active material 22 increases the overall battery capacity. be able to. (According to the second electrode active material 22 of the present invention, the function as the electrode active material is exhibited while the function as the binder material is exhibited, so (total battery capacity) = (first electrode (Capacity of active material particles) + (capacity of second electrode active material) and increases.)

  In addition, as a result of paying attention to the lattice constants of the first electrode active material particles 21 and the second electrode active material 22, the inventors of the present application as the second electrode active material 22, the first electrode active material particles 21. It has been found that charge / discharge speed can be increased by using an electrode active material having a larger lattice constant than the above. Therefore, in the positive electrode plate for a non-aqueous electrolyte secondary battery according to the present invention, the lattice constant of the second electrode active material 22 is defined to be larger than that of the first electrode active material particles 21. ing.

  Below, the mechanism which has the above-mentioned effect which is estimated at present is demonstrated using FIG. FIG. 2 is a conceptual diagram for explaining the state of the first electrode active material particles 21 and the second electrode active material 22 of the positive electrode plate 10 for a non-aqueous electrolyte secondary battery of the present invention during charging and discharging. is there.

  In the positive electrode plate of the lithium ion secondary battery at the time of charging, alkali metal ions (as shown in FIG. 2) are formed from the first electrode active material particles 21 and the second electrode active material 22 constituting the electrode active material layer 2. Reaction to release lithium ions).

  Here, the electrode active material layer in the present invention is composed of the first electrode active material particles 21 and the second electrode active material 22, and the lattice constant of the second electrode active material 22 is the first constant. It is larger than the lattice constant of the electrode active material particles 21. The present inventors paid attention to the lattice constant of the active material, and found that the permutation of the lattice constant coincides with the alkali metal ion loading / unloading speed of the experimental result. From this, it is presumed that the higher the lattice constant of the active material, the faster the rate of alkali metal ions in and out. Therefore, as shown in FIG. 2A, immediately after the start of charging, the first electrode active material particles 22 are released around the first electrode active material 21 earlier than the release of alkali metal ions. It is presumed that the existing second electrode active material 22 releases alkali metal ions.

  In addition, as shown in FIG. 2B, when charging proceeds, the first electrode active material particles 21 also release alkali metal ions. At this time, the inside and outside of the first electrode active material particles 21 It is presumed that there is a difference in the lithium concentration between the two, and the alkali metal ions inside the first electrode active material particles 21 move to the outside due to the concentration diffusion and are easily released. That is, it can be said that the charge of the first electrode active material particles 21 was promoted by the presence of the second electrode active material 22, and it can be considered that the speeding up of the charge was also realized.

  It is assumed that the reverse phenomenon occurs during discharge, that is, the same phenomenon occurs when alkali metal ions are introduced, and the discharge speed is also increased.

  Although it is not necessarily clear whether the present invention having the above-described effects is in accordance with the above-described mechanism, at least the first electrode active material 21, the current collector 1, and the first electrode active material particles It is clear that the charge / discharge speed can be increased by fixing with the second electrode active material 22 having a larger lattice constant than the first electrode active material particles 21. That is, in the present invention, for example, as in the prior art, the first electrode active material particles 21, the current collector 1, and the first electrode active material particles 21 are fixed only with a resin binder. The positive electrode plate, the first electrode active material particles 21 and the current collector 1, and the first electrode active material particles 21 are fixed together with an electrode active material having a lattice constant smaller than that of the first electrode active material particles 21. Compared to the positive electrode plate, the charge / discharge speed can be increased.

  Next, the “lattice constant” in the present invention will be described. The minimum unit of the crystal lattice is called a unit cell (sometimes referred to as a unit cell), which is a parallelepiped having lattice points at eight corners. The lengths of the three edges intersecting at one corner of the hexahedron, that is, the distances between the lattice points are a, b, and c, and the angles between the edges b and c, the edges c and a, and the edges a and b are α , Β, γ, a, b, c and α, β, γ are called lattice constants.

  The number of lattice constants varies depending on the crystal lattice (crystal system). For example, in the case of a cubic lattice, α, β, and γ are all right angles and a, b, and c are all equal, so only a is specified as the lattice constant. do it. In the orthorhombic lattice, α, β, and γ are right angles, so only a, b, and c need to be specified. In the hexagonal lattice, α and β are right angles, γ is a constant angle of 120 degrees, and a and b are equal, so a and b are lattice constants. In the present invention, the value of a (a-axis value) is used as the lattice constant regardless of the crystal lattice. The value a which is the lattice constant of the present invention can be determined accurately by measuring X-ray diffraction.

  Here, as the second electrode active material 22 constituting the positive electrode plate of the present invention, (1) an alkali metal ion insertion / desorption reaction is performed even if it is other than the materials listed above, (2) The current collector, the first electrode active material particles 21 and the first electrode active material 21 can be fixed to each other, and (3) a lattice constant larger than the lattice constant of the first electrode active material particles 1 What is necessary is just to satisfy | fill the three conditions of what it has, and it is not limited to the substance quoted above. For example, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Fr, Ra, As long as it is a single metal oxide of a metal element such as Ce and Ce or a composite metal oxide containing two or more metal elements and satisfies the above three conditions, the second electrode active It can be used as the substance 22.

  In the present invention, when the first electrode active material particles 21, the current collector 1, and the first electrode active material particles 21 are fixed by the second electrode active material 22, These two aspects are included. The first fixing mode is between the objects to be fixed (for example, between the first electrode active material particles 21 and the current collector 1, between the first electrode active material particles 21, or when using a conductive material. In this embodiment, the second electrode active material 22 is interposed between the conductive material and the first electrode active material particles 21, between the conductive material particles, etc.) to fix them together. In the second fixing mode, the objects to be bonded are in direct contact with each other, and the objects to be bonded are fixed to each other by the presence of the second electrode active material 22 surrounding the contact portion. In the present invention, the electrode active material layer 2 has any one of the first fixing mode and the second fixing mode, or both modes. In particular, as the particle diameter of the first electrode active material particles 21 contained in the electrode active material layer becomes smaller, the second fixing mode tends to increase.

  The second electrode active material 22 may be present in the electrode active material layer in such a shape that the objects to be bonded are fixed in the first fixing mode or the second fixing mode. The size and shape of the electrode active material 22 are not particularly limited. For example, the second electrode active material 22 is in the form of fine particles, and the second electrode active material 22 having a large number of fine particles is one or more of the first electrode active materials 21. It may be present so as to surround the entire surface or a part of the aggregate.

  In particular, as shown in FIG. 1B, the electrode active material layer 2 includes a portion connected by continuous crystal lattices in a part of the adjacent second electrode active materials 22. Is preferred. With this configuration, the input / output characteristics can be improved. As described above, the second electrode active material 22 in the present invention is for fixing the first electrode active material particles 21 on the current collector 1, and as shown in FIG. It is presumed that the film adhesiveness of the electrode active material layer 2 is improved by including at least a part of the two electrode active materials 22 connected by the continuous crystal lattice. And it is thought that this improvement in film adhesion contributes to the improvement in the input / output characteristics.

  Further, from the viewpoint of improving the film adhesion of the electrode active material layer 2, a portion where the crystal lattices of the adjacent second electrode active materials 22 are continuous may be significantly present in the electrode active material layer 2. More desirable. In the present invention, whether or not the crystal lattices of the second electrode active materials 22 are continuous is determined by observing the crystal lattice of the cross section of the adjacent second electrode active material 22 in the electrode active material layer with a transmission electron microscope. It can be confirmed by doing.

  In order to configure the electrode active material layer of the present invention so as to include a portion where crystal lattices in the adjacent second electrode active materials 22 are continuous, the positive electrode plate of the present invention is manufactured according to the manufacturing method of the present invention described later. It is desirable to do. That is, in the production method of the present invention, an electrode active material layer forming liquid is applied onto a current collector to form a coating film, and the electrode active material layer is formed from the coating film by performing means such as heating. . At that time, a metal element-containing compound present around the first electrode active material particles causes a reaction such as thermal decomposition and oxidation on the current collector, and the second electrode around the first electrode active material particles. The electrode active material 22 is generated. At this time, if a part of the adjacent second electrode active materials 22 (or their precursors) are joined together, the crystal growth of the two tends to proceed simultaneously at the joined portion. As a result of the simultaneous crystal growth at the junction, the electrode active material layer of the present invention is configured to include a portion where the crystal lattices of the adjacent second electrode active materials 22 are continuous.

  Further, the second electrode active material 22 is non-particulate, and the space between the first electrode active material particles 21 and the current collector 1 and between the first electrode active material particles 21 is filled with leaving a gap. It may be a continuous body. Alternatively, even if the second electrode active material 22 forms a continuous coating layer in the form of a film, a pleat, or a hump that surrounds two or more aggregates of the first electrode active material particles 21. Good. Further, the surface of the second electrode active material 22 is observed in a smooth state when observed at the scanning electron microscope level, for example, with a large number of protrusions densely packed, or with particles between the surfaces. Or a combination thereof, and the surface state is not limited at all. That is, the second electrode active material 22 in the present invention surrounds at least a part of the first electrode active material 21 and the second electrode active materials 22 are connected to each other, or the second electrode active material 22 is In addition, the second electrode active material 22 in the vicinity of the current collector 1 in the second electrode active material 22 is connected to the surface of the current collector 1 to form the electrode active material layer 2. Anything is acceptable.

  In addition, all the second electrode active materials 22 contained in the electrode active material layer 2 are bonded between the current collector 1 and the first electrode active material particles 21 and between the first electrode active material particles 21. There is no need to contribute to fixation. For example, the second electrode active material 22 fixed to the first electrode active material particles 21 may be present so as not to be fixed to the current collector 1 or the first electrode active material particles 21.

  In addition, the present invention does not prohibit the use of a resin binder as a so-called binder, and the resin binder and the second electrode active material 22 are used together, and these binders are used to cover the binder. It is good also as fixing between fixed things. In the case where the resin binder and the second electrode active material 22 are used together as a so-called binder, the total mass of the binder (total mass of the resin binder + the total of the second electrode active material 22). As the ratio of the second electrode active material 22 to the mass (mass) increases, the input / output characteristics improve and the capacity of the entire battery also increases. Considering such points, the ratio of the second electrode active material 22 to the total mass of the so-called binder material is preferably in the range of 50 to 100% by mass. Of course, even in a case outside the range, it goes without saying that the input / output characteristics are improved and the battery capacity is increased as much as the second electrode active material 22 is contained.

  Moreover, even if the electrode active material layer 2 contains two or more kinds of first electrode active material particles, at least one of the first electrode active material particles and the second electrode among them. If the active material satisfies the relationship of the present invention described above, the effects of the present invention can be achieved.

The presence or absence of an alkali metal ion insertion / elimination reaction of the electrode active material can be confirmed by an electrochemical measurement (cyclic voltammetry: CV) method. The CV test will be described below. Specifically, in the appropriate voltage range of the active material, for example, lithium ions are assumed as alkali metal ions, and if the active material is LiMn ₂ O ₄ , after sweeping from 3.0 V to 4.3 V, The operation of returning to 3.0 V again is repeated about three times. The scanning speed is preferably 1 mV / sec. For example, in the case of LiMn ₂ O ₄ , as shown in FIG. 3, an oxidation peak corresponding to the Li elimination reaction of LiMn ₂ O ₄ appears in the vicinity of about 3.9 V, and the Li insertion reaction occurs in the vicinity of about 4.1 V. A corresponding reduction peak appears, whereby the presence or absence of an alkali metal ion insertion / extraction reaction can be confirmed. Further, as shown in FIG. 4, when no peak appears, it can be determined that there is no alkali metal ion insertion / desorption reaction.

(Mixing ratio)
In the present invention, the mixing ratio of the first electrode active material particles 21 and the second electrode active material 22 contained in the electrode active material layer 2 is not particularly limited, and the first electrode active material used is not limited. It can be appropriately determined in consideration of the type and size of the particles 21 and the function required for the second electrode active material 22.

  On the other hand, when the content of the second electrode active material acting as a binding material is too small, the current collector 1, the first electrode active material particle 22, and the first electrode active material particles 22 There is a possibility that the fixing force cannot be increased to a desired level, or a request for increasing the charge / discharge speed cannot be sufficiently satisfied. Therefore, considering this point, when the mass ratio of the first electrode active material particles 21 is 100 parts by mass, the mass ratio of the second electrode active material 22 is 1 part by mass or more and 100 parts by mass or less. It is preferable.

  In the production of the positive electrode plate for a non-aqueous electrolyte secondary battery of the present invention, the presence or absence of the alkali metal ion insertion / desorption reaction of the second electrode active material 22 to be contained in the electrode active material layer 2 is described above. It can be confirmed as follows. Therefore, after confirmation in advance, a metal element or metal oxide exhibiting an alkali metal ion insertion / release reaction can be present in the electrode active material layer. On the other hand, whether or not a metal element or metal oxide exhibiting an alkali metal ion insertion / release reaction is contained in the electrode active material layer of the already completed positive electrode plate can be confirmed as follows, for example. That is, it is possible to estimate what kind of metal element or metal oxide is contained in the sample by cutting the electrode active material layer to prepare a sample and conducting composition analysis of the sample. Then, a film made of the estimated metal element or metal oxide is formed on a substrate such as glass and subjected to a cyclic voltammetry test, whereby the metal element or metal oxide is inserted and desorbed by alkali metal ions. It can be confirmed whether the reaction is shown or not.

(Other materials)
The electrode active material layer 2 may be composed of only the first electrode active material particles 21 and the second electrode active material 22, but further additives may be included without departing from the spirit of the present invention. May be formed. For example, according to the present invention, good conductivity can be exhibited without using a conductive material exemplified by a conductive carbon material such as carbon black, but better conductivity is desired. Depending on the case or the type of active material particles, a conductive material may be used.

(Method for producing positive electrode plate for non-aqueous electrolyte secondary battery)
Next, a method for producing a positive electrode plate for a non-aqueous electrolyte secondary battery of the present invention (hereinafter sometimes simply referred to as “the production method of the present invention”) will be described. The production method of the present invention contains electrode active material particles and one or more metal element-containing compounds that are heated to become an electrode active material having a larger lattice constant than the electrode active material particles. An electrode active material layer forming liquid is applied to at least a part of the current collector to form a coating film, and the coating film formed in the coating process is composed of a metal element-containing compound and an electrode active material (first And a heating step of heating at a temperature equal to or higher than the temperature of the second electrode active material.

  According to the manufacturing method of the present invention, the above-described positive electrode plate of the present invention can be manufactured with high yield. This will be specifically described below.

(Coating process)
The coating step includes an electrode active material layer containing electrode active material particles and one or more metal element-containing compounds that are heated to become an electrode active material having a lattice constant larger than that of the electrode active material particles. In this step, the forming liquid is applied to at least a part of the current collector to form a coating film.

<Preparation of electrode active material layer forming solution>
The electrode active material particles used for the preparation of the electrode active material layer forming liquid can be the same as the first electrode active material particles described above, and the description thereof is omitted here. In addition, in the manufacturing method of this invention, it is the same as the above-mentioned that the particle diameter of the electrode active material particle used can select a desired magnitude | size.

  In addition, in the electrode active material layer forming liquid, one or two or more metal element-containing compounds that are heated to become an electrode active material having a lattice constant larger than that of the electrode active material particles are added.

  The metal element-containing compound is a precursor of an electrode active material that exhibits a function as a so-called binder that fixes the electrode active material particles and the current collector and the electrode active material particles to each other. Therefore, as long as it can generate an electrode active material having a lattice constant larger than that of the electrode active material particles by being applied to the substrate in a state of being added to the electrode active material layer forming liquid and heated. Any metal element-containing compound may be used.

  Whether or not the electrode active material produced from the metal element-containing compound to be used exhibits an alkali metal ion insertion / desorption reaction is determined in a preliminary experiment by placing an electrode active material layer forming liquid containing the metal element-containing compound on the substrate. An electrode active material can be formed by coating and heating, and can be confirmed by the cyclic voltammetry method described above.

  As the metal element-containing compound, a lithium element-containing compound and one or more metal element-containing compounds containing any metal element selected from cobalt, nickel, manganese, iron or titanium are preferably used. Can do. The metal element-containing compound may be an inorganic metal element-containing compound in which no carbon is contained in the compound, or an organometallic element-containing compound constituted by containing carbon in the compound. Also good. In the present invention and the present specification, the inorganic metal element-containing compound and the organic metal-containing compound may be simply referred to as a metal element-containing compound.

  Examples of the metal element-containing compound include chloride, nitrate, sulfate, perchlorate, acetate, phosphate, bromate and the like of other metal elements such as lithium element or cobalt. Among them, in the present invention, chloride, nitrate, and acetate are preferably used because they are easily available as general-purpose products. In particular, nitrate is preferably used because it has good film forming properties for a wide variety of current collectors.

For example, as the metal element-containing compound for generating LiCoO ₂ as an electrode active material for fixing the current collector, the electrode active material particles, and the electrode active material particles, a Li element-containing compound and a Co element-containing compound Can be used in combination as a main raw material, and other raw materials can be used in combination as required. Examples of the Li element-containing compound include lithium citrate tetrahydrate, lithium perchlorate trihydrate, lithium acetate dihydrate, lithium nitrate, and lithium phosphate. Examples of the compound include cobalt (II) chloride hexahydrate, cobalt (II) formate dihydrate, cobalt (III) acetylacetonate, cobalt (II) acetylacetonate dihydrate, cobalt acetate (II ) Tetrahydrate, cobalt (II) oxalate dihydrate, cobalt (II) nitrate hexahydrate, cobalt (II) ammonium chloride hexahydrate, sodium cobalt (III) nitrite, and cobalt sulfate ( II) The heptahydrate etc. are mentioned. The combination ratio (Li: Co = X: 1) of the Li element-containing compound and the Co element-containing compound used as the main raw material is not particularly limited, but is preferably 1 ≦ X <2, and preferably 1 ≦ X ≦ 1. 2 is more preferable.

Also, for example, as a metal element-containing compound for generating LiNiO ₂ as an electrode active material for fixing the current collector and the electrode active material particles, and the electrode active material particles, the Li element-containing compound and the Ni element-containing compound A compound can be used in combination as a main raw material, and further, other raw materials can be used in combination as required. Examples of the Li element-containing compound are the same as in the case of producing LiCoO ₂ described above. Examples of the Ni element-containing compound include nickel chloride (II) hexahydrate and nickel acetate (II) tetrahydrate. , Nickel (II) perchlorate hexahydrate, nickel (II) bromide trihydrate, nickel (II) nitrate hexahydrate, nickel (II) acetylacetonate dihydrate, hypophosphorous acid Examples thereof include nickel (II) acid hexahydrate and nickel (II) sulfate hexahydrate. The combination ratio (Li: Ni = X: 1) of the Li element-containing compound and Ni element-containing compound used as the main raw material is not particularly limited, but is preferably 1 ≦ X <2, and preferably 1 ≦ X ≦ 1. 2 is more preferable.

In addition, for example, as a metal element-containing compound for generating LiMn ₂ O ₄ as an electrode active material for fixing the current collector, the electrode active material particles, and the electrode active material particles, a Li element-containing compound, and Mn Element-containing compounds can be used in combination as main raw materials, and other raw materials can be used in combination as required. Examples of the Li element-containing compound are the same as in the case of producing LiCoO ₂ described above, and examples of the Mn element-containing compound include manganese acetate (III) dihydrate and manganese nitrate (II) hexahydrate. Products, manganese (II) sulfate pentahydrate, manganese (II) oxalate dihydrate, manganese (III) acetylacetonate, and the like. The combination ratio (Li: Mn = X: 1) of the Li element-containing compound and the Mn element-containing compound used as the main raw material is not particularly limited, but is preferably 0.5 ≦ X <1, 0.5 ≦ More preferably, X ≦ 0.6.

Also, for example, as a metal element-containing compound for generating LiFeO ₂ as an electrode active material for fixing the current collector and the electrode active material particles, and the electrode active material particles, the Li element-containing compound and the Fe element-containing compound A compound can be used in combination as a main raw material, and further, other raw materials can be used in combination as required. Examples of the Li element-containing compound are the same as in the case of producing LiCoO ₂ described above. Examples of the Fe element-containing compound include iron (II) chloride tetrahydrate, iron (III) citrate, and acetic acid. Examples include iron (II), iron (II) oxalate dihydrate, iron (III) nitrate nonahydrate, iron (II) lactate trihydrate, and iron (II) sulfate heptahydrate. . The combination ratio (Li: Fe = X: 1) of the Li element-containing compound and the Fe element-containing compound used as the main raw material is not particularly limited, but is preferably 1 ≦ X <2, and preferably 1 ≦ X ≦ 1. 2 is more preferable.

Further, for example, as a metal element-containing compound for producing Li ₄ Ti ₅ O ₁₂ as an electrode active material for fixing the current collector and the electrode active material particles, and the electrode active material particles, a Li element-containing compound, In addition, the Ti element-containing compound can be used in combination as a main raw material, and other raw materials can be used in combination as required. Examples of the Li element-containing compound are the same as in the case of producing LiCoO ₂ described above, and examples of the Ti element-containing compound include titanium tetrachloride and titanium acetylacetonate. The combination ratio (Li: Ti = X: 1) of the Li element-containing compound and the Ti element-containing compound used as the main raw material is not particularly limited, but is preferably 1 ≦ X <2, preferably 1 ≦ X ≦ 1. 2 is more preferable.

  In the electrode active material layer forming liquid described above, the ratio of the total amount of one or more metal element-containing compounds added in the solvent is 0.01 to 5 mol / L, particularly 0.1 to 5 mol / L. 2 mol / L is preferred. By setting the concentration to 0.01 mol / L or more, the current collector and the electrode active material layer generated on the surface of the current collector can be satisfactorily adhered, and the active material particles can be fixed. . In addition, by setting the concentration to 5 mol / L or less, it is possible to maintain a good viscosity enough to apply the electrode active material layer forming liquid to the current collector surface, and to form a uniform coating film. can do.

  Further, the electrode active material layer forming liquid may be blended with a conductive material, an organic substance that is a viscosity adjusting agent of the electrode active material layer forming liquid, or other additives within the scope of the present invention. Good. The solvent for dissolving the metal element-containing compound may be any solvent that can dissolve the metal element-containing compound, and a conventionally known solvent can be appropriately selected and used. For example, water, lower alcohols such as NMP (N-methyl-2-pyrrolidone), methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, 2-butanol, t-butanol, acetylacetone, diacetyl And ketones such as benzoylacetone, ketoesters such as ethyl acetoacetate, ethyl pyruvate, ethyl benzoylacetate and ethyl benzoylformate, toluene, ethylene glycol, diethylene glycol, polyethylene glycol, and mixed solvents thereof.

  The method for applying the electrode active material layer forming liquid onto the current collector is not particularly limited, and a general application method can be appropriately selected and used. For example, the electrode active material layer forming liquid can be applied to any region of the current collector surface by printing, spin coating, dip coating, bar coating, spray coating, or the like. In addition, when the surface of the current collector is porous, has a large number of irregularities, or has a three-dimensional structure, it can be manually applied in addition to the above method. Note that the current collector used in the present invention can further improve the film-forming property of the electrode active material layer by performing corona treatment, oxygen plasma treatment, or the like in advance as necessary.

  Moreover, although there is no limitation in particular about the application quantity of an electrode active material layer formation liquid, it is preferable to apply | coat in the range that the thickness after a heating becomes the thickness of the electrode active material layer demonstrated above.

(Heating process)
The heating step is a step of heating the coating film formed in the coating step described above to evaporate the solvent and generating an electrode active material (second electrode active material) from the metal element-containing compound.

  By the heating step, the current collector, the electrode active material particles, and the electrode active material particles are fixed by an electrode active material having a lattice constant larger than that of the electrode active material particles.

  About the heating temperature in a heating process, what is necessary is just the temperature which can produce | generate an electrode active material from the metal element containing compound used, Therefore Therefore, it can set suitably according to these kind. Specifically, for example, the electrode active material can be generated by heating at a temperature equal to or higher than the temperature at which the metal element-containing compound is thermally decomposed.

  For example, the heating method is not particularly limited as long as it is a heating method or a heating apparatus that can heat the coating film at a temperature at which the metal element-containing compound is thermally decomposed. For example, a method of using any one of a hot plate, an oven, a heating furnace, an infrared heater, a halogen heater, a hot air blower, etc., or a combination of two or more can be mentioned.

  Further, the heating atmosphere in the heating step is not particularly limited, and can be appropriately determined in consideration of the material used for manufacturing the positive electrode plate, the heating temperature, the oxygen potential of the metal element, and the like. For example, an air atmosphere is preferable in that a special atmosphere adjustment is not necessary and the heating process can be easily performed. In particular, when an aluminum foil is used as the current collector, the heating step can be preferably performed because there is no possibility that the aluminum foil is oxidized even if the heating step is performed in an air atmosphere.

  On the other hand, when copper foil is used as the current collector, it is not desirable because it is oxidized when the heating step is performed in an air atmosphere. Therefore, in such a case, it is preferable to heat in an inert gas atmosphere, a reducing gas atmosphere, or a mixed gas atmosphere of an inert gas and a reducing gas. In the case where the heating step is performed in an atmosphere that does not contain sufficient oxygen gas, when an electrode active material made of a metal oxide is generated in the electrode active material layer, the metal element in the metal element-containing compound Oxidation needs to be realized by combining oxygen and metal element in the compound contained in the electrode active material layer forming liquid, so it is necessary to use a compound containing oxygen element in the compound to be used There is.

  In the production method of the present invention, the inert gas atmosphere or the reducing gas atmosphere is not particularly limited to a specific atmosphere, and the production method of the invention can be appropriately carried out under these conventionally known atmospheres. Examples of the active gas atmosphere include argon gas, nitrogen gas, and reducing gas atmosphere, such as hydrogen gas, carbon monoxide gas, or a gas atmosphere in which the inert gas and the reducing gas are mixed.

(Non-aqueous electrolyte secondary battery)
Next, the nonaqueous electrolyte secondary battery of the present invention will be described with reference to FIG. FIG. 5 is a schematic view showing an example of the non-aqueous electrolyte secondary battery 100 of the present invention. As shown in FIG. 5, the nonaqueous electrolyte secondary battery of the present invention includes a positive electrode plate 10 in which an electrode active material layer 2 is provided on one side of a current collector 1, and a collector combined therewith. It is composed of a negative electrode plate 50 in which an electrode active material layer 54 is provided on one surface side of the electric body 55, and a separator 70 provided between the positive electrode plate 10 and the negative electrode plate 50. It is accommodated in the container comprised by this, and the structure sealed in the state with which the nonaqueous electrolyte solution 90 was filled in the container is taken.

  Here, the nonaqueous electrolyte secondary battery of the present invention is characterized in that the positive electrode plate 10 for a nonaqueous electrolyte secondary battery described above is used as an essential configuration as a positive electrode plate. The non-aqueous electrolyte secondary battery of the present invention is not particularly limited with respect to other requirements as long as it satisfies this requirement, and a conventionally known negative electrode plate, non-aqueous electrolyte, and container may be appropriately selected and used. The configuration is not limited to that shown in FIG. In addition, about the positive electrode plate for nonaqueous electrolyte secondary batteries of this invention, it is as having demonstrated above, and detailed description is abbreviate | omitted.

(Positive electrode plate)
The non-aqueous electrolyte secondary battery of the present invention is characterized by using the above-described positive electrode plate of the present invention as the positive electrode plate. As described above, the positive electrode plate of the present invention can meet the demand for higher charge / discharge speed even when a high-capacity active material is used as the first electrode active material particles 21. . Therefore, by using such a positive electrode plate, the performance of the positive electrode plate is exhibited also in the non-aqueous electrolyte secondary battery of the present invention.

(Negative electrode plate)
As the negative electrode plate, a conventionally known negative electrode plate for a non-aqueous electrolyte secondary battery can be appropriately selected and used. Generally, as a conventionally known negative electrode plate, a copper foil such as an electrolytic copper foil or a rolled copper foil having a thickness of about 5 to 50 μm is used as a current collector, and the negative electrode plate is formed on at least a part of the current collector surface. The electrode active material layer forming solution is applied, dried, and pressed as necessary. The electrode active material layer forming liquid in the negative electrode plate generally includes an active material made of a carbonaceous material such as natural graphite, artificial graphite, amorphous carbon, carbon black, or a material obtained by adding a different element to these components, Alternatively, negative electrode active material particles such as materials capable of occluding and releasing lithium ions, such as metal oxides such as Li ₄ Ti ₅ O ₁₂ , metal lithium and alloys thereof, tin, silicon, and alloys thereof, and resin binders, Generally, other additives such as a conductive material are dispersed and mixed as necessary, but the present invention is not limited to this.

(Non-aqueous electrolyte)
The non-aqueous electrolyte 90 used in the present invention is not particularly limited as long as it is generally used as a non-aqueous electrolyte for a non-aqueous electrolyte secondary battery, but when used for a lithium ion secondary battery. For this, a nonaqueous electrolytic solution in which a lithium salt is dissolved in an organic solvent is preferably used.

Examples of the lithium salt include inorganic lithium salts such as LiClO ₄ , LiBF ₄ , LiPF ₆ , LiAsF ₆ , LiCl, and LiBr; LiB (C ₆ H ₅ ) ₄ , LiN (SO ₂ CF ₃ ) ₂ , LiC ( Organic compounds such as SO ₂ CF ₃ ) ₃ , LiOSO ₂ CF ₃ , LiOSO ₂ C ₂ F ₅ , LiOSO ₂ C ₄ F ₉ , LiOSO ₂ C ₅ F ₁₁ , LiOSO ₂ C ₆ F ₁₃ , and LiOSO ₂ C ₇ F ₁₅ Typical examples include lithium salts.

  Examples of the organic solvent used for dissolving the lithium salt include cyclic esters, chain esters, cyclic ethers, and chain ethers.

  As a structure of the battery manufactured using the positive electrode plate, the negative electrode plate, the separator, and the nonaqueous electrolytic solution, a conventionally known structure can be appropriately selected and used. For example, the structure which winds a positive electrode plate and a negative electrode plate in the shape of a spiral via the separator like a polyethylene porous film, and accommodates in a battery container is mentioned. As another aspect, a structure in which a positive electrode plate and a negative electrode plate cut into a predetermined shape are stacked and fixed via a separator, and this is housed in a battery container may be employed. In any structure, after the positive electrode plate and the negative electrode plate are stored in the battery container, the lead wire attached to the positive electrode plate is connected to the positive electrode terminal provided in the outer container, while the lead wire attached to the negative electrode plate Is connected to a negative electrode terminal provided in the outer container, and the battery container is further filled with a nonaqueous electrolyte and then sealed to produce a nonaqueous electrolyte secondary battery.

(Battery pack)
Next, a battery pack 200 configured using the nonaqueous electrolyte secondary battery 100 of the present invention will be described with reference to FIG. FIG. 6 is a schematic exploded view showing an example of the battery pack 200 of the present invention.

  As shown in FIG. 6, the battery pack 200 includes a non-aqueous electrolyte secondary battery 100 housed in a resin container 36 a, a resin container 36 b, and an end case 37. Further, a protection circuit for preventing overcharge and overdischarge between one end face of the nonaqueous electrolyte secondary battery, which is a face including the positive electrode terminal 32 and the negative electrode terminal 33, and the end case 37. A substrate 34 is provided.

  The protection circuit board 34 includes an external connection connector 35. The external connection connector 35 is connected to an external connection window 38a provided in the resin container 36a and an external connection window 38b provided in the end case 37. Inserted and connected to external terminals. The protection circuit board 34 is mounted with a charge / discharge safety circuit (not shown) for controlling charge / discharge, a wiring circuit for connecting the external connection terminal and the nonaqueous electrolyte secondary battery 100, and the like. .

  As the battery pack 200, a configuration of a conventionally known battery pack can be appropriately selected except that the nonaqueous electrolyte secondary battery 100 using the positive electrode plate 10 of the present invention is used. Although not shown, the battery pack 200 includes a positive electrode lead plate connected to the positive electrode terminal 32, a negative electrode lead plate connected to the negative electrode terminal 33, and an insulator between the nonaqueous electrolyte secondary ground 100 and the end case 37. Etc. may be provided as appropriate.

  In addition, the nonaqueous electrolyte secondary battery 100 of the present invention using the positive electrode plate 10 of the present invention is not limited to the usage mode for the battery pack, and further functions such as blocking of excessive current, battery temperature monitoring, etc. And the protection circuit may be used by being integrated with the non-aqueous electrolyte secondary battery. In such an embodiment, the battery pack can be used as a secondary battery having a protection function and a protection circuit without constituting a battery pack, and is highly versatile. In addition, some aspects demonstrated above are only illustrations, and do not limit the use of the positive electrode plate 10 of this invention, or the nonaqueous electrolyte secondary battery 100 of this invention at all.

  Next, the present invention will be described more specifically with reference to examples and comparative examples. Hereinafter, unless otherwise specified, parts or% is based on mass.

Example 1
Li (CH ₃ COO) · 2H ₂ O [molecular weight: 102.02]: 2 g, Mn (CH ₃ COO) ₂ · 4H ₂ O [molecular weight: 245.09]: 9 g, and methanol: 11 g By mixing, a raw material liquid for producing a lithium composite oxide exhibiting a lithium ion insertion / release reaction was obtained. Next, the raw material solution: 13 g, the positive electrode active material having an average particle size of 8 μm LiNi _1/3 Co _1/3 Mn _1/3 O ₂ : 10 g, and acetylene black (Denka Black, Denki Kagaku Kogyo Co., Ltd.): 1 .2 g, carbon fiber (manufactured by Showa Denko KK, VGCF): 0.25 g, and resin hydroxyethyl cellulose: 0.2 g of a thickener aqueous solution dissolved in 9.8 g of pure water: 15 g and a solvent (methanol) And kneading with an Excel auto homogenizer (Nippon Seiki Seisakusho Co., Ltd.) at a rotational speed of 8000 rpm for 15 minutes to prepare an electrode active material layer forming solution. An aluminum plate having a thickness of 15 μm is prepared as a current collector, and an electrode prepared as described above on one surface side of the current collector in an amount such that the electrode mass of the electrode active material layer finally obtained is 45 g / m ² The active material layer forming liquid was applied with an applicator to form an electrode active material layer forming coating film. Subsequently, the coating film was pressed using a roll press machine (manufactured by Sank Metal Co., Ltd .: mechanical type 1 ton) under the conditions of applied pressure: 0.1 ton / cm and pressing speed of 10 mm / second. Thereafter, the current collector with the electrode active material layer forming coating film formed thereon was placed in a normal temperature electric furnace (muffle furnace, manufactured by Denken, P90) and heated from room temperature to 450 ° C. over 60 minutes. Thus, a positive electrode plate for a non-aqueous electrolyte secondary battery in which an electrode active material layer was laminated on the current collector was obtained. And after taking out the said positive electrode plate from an electric furnace and leaving to stand to room temperature, it cut | judged to the predetermined | prescribed magnitude | size (a 15 mm diameter disc) using the press, and it was set as the positive electrode plate of Example 1. In addition, it was 28 micrometers when the thickness of the electrode active material layer of Example 1 was measured 10 points | pieces in arbitrary places using the micrometer, and the average value was computed.

(Example 2)
In place of Example 1, positive electrode active material LiNi _0.80 Co _0.15 Al _0.05 O ₂ : 10 g having an average particle diameter of 8 μm was used as positive electrode active material particles, and the electrode mass of the electrode active material layer finally obtained was 37. A positive electrode plate of Example 2 was obtained in the same manner as in Example 1 except that the coating was applied in an amount of 3 g / m ² . In addition, it was 22 micrometers when the thickness of the electrode active material layer of Example 1 was measured 10 points | pieces in arbitrary places using the micrometer, and the average value was computed.

(Example 3)
In place of Example 1, Li (CH ₃ COO) · 2H ₂ O [molecular weight: 102.02]: 2 g, Co (NO ₃ ) ₂ · 6H ₂ O [molecular weight: 290.9]: 30 g, and methanol: An amount in which the electrode mass of the electrode active material layer finally obtained is 41.1 g / m ^{2 as} a raw material liquid for producing a lithium composite oxide exhibiting lithium ion insertion / release reaction by mixing 20 g added A positive electrode plate of Example 3 was obtained in the same manner as in Example 1 except that the coating was performed in the same manner as in Example 1. In addition, it was 26 micrometers when the thickness of the electrode active material layer was measured 10 points | pieces in arbitrary places using the micrometer, and the average value was computed.

Example 4
In place of Example 3, positive electrode active material LiNi _0.80 Co _0.15 Al _0.05 O ₂ : 10 g having an average particle diameter of 8 μm was used as positive electrode active material particles, and the electrode mass of the electrode active material layer finally obtained was 34.8 g. A positive electrode plate of Example 4 was obtained in the same manner as in Example 1 except that the coating amount was / m ² . In addition, it was 20 micrometers when the thickness of the electrode active material layer was measured 10 points | pieces using the micrometer, and the average value was computed.

(Example 5)
A positive electrode plate of Example 1 was immersed in an immersion tank filled with a resin mixture prepared by using PVDF resin as a resin material and mixing with an NMP solvent so that the concentration of PVDF was 0.1%. The resin mixture was sufficiently permeated into the voids of the layer. Then, the positive electrode plate of Example 1 was taken out from the said immersion layer, was installed in the oven heated at 150 degreeC, and was dried for 15 minutes, and the solvent of the resin liquid mixture was removed. As a result, a positive electrode plate of Example 5 in which the resin binder remained in the electrode active material layer was obtained. In addition, it was 29 micrometers when the thickness of the electrode active material layer of Example 5 was measured 10 points | pieces using the micrometer, and the average value was computed.

(Example 6)
The positive electrode plate of Example 1 was immersed in an immersion tank filled with a resin mixture prepared by using PVDF resin as a resin material and mixing with an NMP solvent so that the concentration of PVDF was 5%. The resin mixture was sufficiently permeated into the voids. Then, the positive electrode plate of Example 1 was taken out from the said immersion layer, was installed in the oven heated at 150 degreeC, and was dried for 15 minutes, and the solvent of the resin liquid mixture was removed. As a result, a positive electrode plate of Example 6 in which the resin binder remained in the electrode active material layer was obtained. In addition, it was 31 micrometers when the thickness of the electrode active material layer of Example 6 was measured 10 points | pieces using the micrometer, and the average value was computed.

(Comparative Example 1)
LiNi _1/3 Co _1/3 Mn _1/3 O ₂ powder having an average particle diameter of 8 μm as a positive electrode active material: 10 g, acetylene black (Denka Black, Denki Kagaku Kogyo Co., Ltd.) as a conductive agent: 1.2 g, and binding PVDF (manufactured by Kureha, KF # 1320): 0.9 g of organic solvent, NMP (manufactured by Mitsubishi Chemical): PVDF resin solution dissolved in 10 g is dispersed, and Excel Auto Homogenizer (Nippon Seiki Seisakusho Co., Ltd.) The mixture was stirred at 8000 rpm for 15 minutes to prepare a slurry-like electrode active material layer forming liquid. An aluminum plate having a thickness of 15 μm was prepared as a current collector, and an electrode active material layer forming solution was applied in an amount such that the electrode mass of the electrode active material layer was 47.3 g / m ² . Drying was performed in an air atmosphere for 20 minutes to obtain a positive electrode plate for a non-aqueous electrolyte secondary battery in which an electrode active material layer was laminated on a current collector. Subsequently, it cut | judged to the predetermined | prescribed magnitude | size (disc 15mm in diameter) using a press, and was vacuum-dried at 120 degreeC for 12 hours, and the positive electrode plate of the comparative example 1 was obtained. In addition, the thickness of the electrode active material layer was measured at 10 points using a micrometer to produce an electrode plate for a nonaqueous electrolyte secondary battery positive electrode. The average value was calculated to be 28 μm.

(Comparative Example 2)
In place of Comparative Example 1, a positive electrode active material LiNi _0.80 Co _0.15 Al _0.05 O ₂ : 10 g having an average particle diameter of 8 μm was used, except that the electrode mass of the electrode active material layer was applied in an amount of 37.2 g / m ^2. Were the same as in Comparative Example 1 to obtain a positive electrode plate of Comparative Example 2. In addition, it was 24 micrometers when the thickness of the electrode active material layer was measured 10 points | pieces in arbitrary places using the micrometer, and the average value was computed.

(Comparative Example 3)
Li (CH ₃ COO) · 2H ₂ O [molecular weight: 102.02]: 15 g, Mn (CH ₃ COO) ₂ · 4H ₂ O [molecular weight: 245.09]: 12 g, Co (CH ₃ COO) ₂ · 4H ₂ O [Molecular weight: 249.08]: 12 g, Ni (CH ₃ COO) ₂ .4H ₂ O [Molecular weight: 248.84]: 12 g, methanol: 50 g added, and lithium ion insertion A raw material solution for producing a lithium composite oxide exhibiting an elimination reaction was used. Next, 30 g of the above raw material liquid, positive electrode active material LiMn ₂ O ₄ : 10 g having an average particle diameter of 4 μm, acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.): 1.2 g, carbon fiber (Showa Denko Co., Ltd.) VGCF) 0.25g, a thickener aqueous solution 15g in which resin hydroxyethyl cellulose 0.2g was dissolved in 9.8g of pure water, and solvent methanol were mixed, and 8000rpm with an Excel auto homogenizer (Nippon Seiki Seisakusho Co., Ltd.). An electrode active material layer forming liquid was prepared by kneading at a rotational speed for 15 minutes. In the same manner as in Example 1, an aluminum plate having a thickness of 15 μm was prepared as a current collector, and the electrode mass of the electrode active material layer finally obtained was 39.1 g / m ^2, and the current collector was used. The electrode active material layer forming liquid prepared above was applied to one surface of the electric body with an applicator to form an electrode active material layer forming coating film. Subsequently, the coating film was pressed using a roll press machine (manufactured by Sank Metal Co., Ltd .: mechanical type 1 ton) under the conditions of applied pressure: 0.1 ton / cm and pressing speed of 10 mm / second. Thereafter, the current collector with the electrode active material layer forming coating film formed thereon was placed in a normal temperature electric furnace (muffle furnace, manufactured by Denken, P90) and heated from room temperature to 450 ° C. over 60 minutes. Thus, a positive electrode plate for a non-aqueous electrolyte secondary battery in which an electrode active material layer was laminated on the current collector was obtained. And after taking out the said positive electrode plate from an electric furnace and leaving it until it became room temperature, it cut | judged to the predetermined | prescribed magnitude | size (disc 15mm in diameter) using the press, and this was made into the positive electrode plate of the comparative example 3. In addition, it was 24 micrometers when the thickness of the electrode active material layer was measured 10 points | pieces in arbitrary places using the micrometer, and the average value was computed.

(Battery characteristics evaluation)
<Production of tripolar coin cell>
Lithium hexafluorophosphate (LiPF ₆ ) is added as a solute to a mixed solvent of ethylene carbonate (EC) / dimethyl carbonate (DMC) (volume ratio = 1: 1), and the concentration of LiPF _{6 as} the solute is 1 mol. The non-aqueous electrolyte was prepared by adjusting the concentration to be / L. Using the examples and comparative examples prepared as described above as the positive electrode plate as the working electrode, the metal lithium plate as the counter electrode plate and the reference electrode plate, the non-aqueous electrolyte prepared above as the electrolyte, The assembly was subjected to the following charge / discharge test.

(Charge test)
The test cell was charged with a constant current (1000 μA) under a 25 ° C. environment until the voltage reached 4.2 V. After the voltage reached 4.2 V, the voltage did not exceed 4.2 V. As described above, the current (discharge rate: 0.1 C) was decreased until it became 5% or less, and charging was performed at a constant voltage, and the battery was fully charged, and then rested for 10 minutes. Here, the “0.1C” means a current value (current value reaching a discharge end voltage) at which the constant current discharge is performed using the tripolar coin cell and the discharge is completed in 10 hours.

(Discharge test)
Thereafter, the fully charged test cell was subjected to constant current (1000 μA) (discharge rate: 0) in an environment of 25 ° C. until the voltage was changed from 4.2 V (full charge voltage) to 3.0 V (discharge end voltage). .1C), the cell voltage (V) is plotted on the vertical axis, the discharge time (h) is plotted on the horizontal axis, discharge curves are prepared, and the initial discharge capacities (μAh) of the positive and negative electrode plates of the examples and comparative examples Asked. Table 1 shows the initial discharge capacity.

(Rate characteristic test, discharge capacity maintenance rate (%) calculation)
In order to evaluate the discharge rate characteristics of the working electrode, each discharge capacity (μAh) at 0.1C, 0.5C, 1C, 10C, and 40C discharge rates was used, and the discharge capacity at the time of 0.1C discharge obtained above was used as a reference. As a result, a discharge capacity retention rate (%) was calculated by calculating a ratio with the discharge capacity at each rate. Specifically, it was calculated by the following (Formula 2).
(Discharge capacity maintenance rate%) = (0.1 C discharge capacity) / (discharge amount at each rate) × 100
... (Formula 2)

  Table 2 shows the discharge capacity retention rates (%) of the examples and comparative examples.

<Measurement of DC resistance value>
In the case where the discharge test was performed under the condition of a discharge rate of 1 C using the test cells of the example and the comparative example, the voltage value (V1) (mV) 10 seconds after the start of the discharge was measured. Furthermore, the voltage value (V10) (mV) 10 seconds after the start of discharge was also measured when the discharge test was performed under the condition of the discharge rate 10C. Then, based on these measured values (V1, V10) and the constant current values (I1, I10) (mA) corresponding to the discharge rates 1C, 10C, the following equation (3) shows the DC resistance value (Ω ) Was measured. Table 3 shows the measurement results of the DC resistance value (Ω).

As can be seen from Table 2, it can be seen that the positive and negative electrode plates of Examples 1 to 6 are faster in charge and discharge than the comparative example. In particular, in Examples 1 to 6, LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , which has been considered to be unable to cope with the increase in charge / discharge speed, is used as the first electrode active material. Although it is used as a particle, speeding up of charge and discharge is exhibited by the presence of the second electrode active material having a larger lattice constant than this. On the other hand, although the first electrode active material particles are the same as those in Examples 1 to 6, the positive electrode plate of Comparative Examples 1 and 2 in which the first electrode active material particles are fixed only with the resin binder, and the first electrode active material Comparative Example 3 in which the lattice constants of the material particles and the second electrode active material are the same, and the positive electrode plate of Comparative Example 4 in which the lattice constant of the second electrode active material is smaller than the lattice constant of the first electrode active material particles Compared with Examples 1-6, although the request | requirement with respect to high capacity | capacitance is satisfied, the request | requirement with respect to the charge / discharge speed-up cannot be satisfied.

  Further, as is clear from Table 3, the positive plates of Examples 1 to 6 were compared with the positive plates of Comparative Examples 1 and 2 that used only the first electrode active material (using a resin binder). The DC resistance value was also low, and good evaluation was also obtained for the input / output characteristics. That is, according to the present invention, it has become clear that the input / output characteristics are also excellent.

DESCRIPTION OF SYMBOLS 1,55 ... Current collector 2,54 ... Electrode active material layer 10 ... Positive electrode plate 21 ... 1st electrode active material particle 22 ... 2nd electrode active material 32 ... Positive terminal 33 ... Negative terminal 34 ... Protection circuit board 35 ... External connector 36a, 36b ... Resin container 37 ... End case 38a, 38b ... External connection window 50 ... Negative electrode plate 70 ... Separator 81, 82 ... Exterior 90 ... Nonaqueous electrolyte 100 ... Nonaqueous electrolyte secondary battery 200 ... Battery pack

Claims (8)

A positive electrode plate for a non-aqueous electrolyte secondary battery comprising a current collector and an electrode active material layer formed on at least a part of the surface of the current collector,
The electrode active material layer contains first electrode active material particles and a second electrode active material;
The first electrode active material particles and the current collector, and the first electrode active material particles are fixed by the second electrode active material,
The positive electrode plate for a non-aqueous electrolyte secondary battery, wherein a lattice constant of the second electrode active material is larger than that of the first electrode active material particles.   The positive electrode plate for a nonaqueous electrolyte secondary battery according to claim 1, wherein the second electrode active material is a lithium composite oxide.   The second electrode active material is a composite oxide of at least one metal selected from cobalt, nickel, manganese, iron, and titanium and lithium. A positive electrode plate for a non-aqueous electrolyte secondary battery according to 1.   4. The electrode active material layer according to claim 1, wherein the electrode active material layer includes a portion where adjacent crystal electrode lattices are connected to each other in a part of adjacent second electrode active materials. 5. The positive electrode plate for nonaqueous electrolyte secondary batteries as described. A non-aqueous electrolyte secondary battery comprising at least a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, and a non-aqueous electrolyte solution,
The said positive electrode plate is a positive electrode plate for nonaqueous electrolyte secondary batteries of any one of Claims 1 thru | or 4, The nonaqueous electrolyte secondary battery characterized by the above-mentioned. Electrode active material layer forming liquid containing electrode active material particles and one or more metal element-containing compounds that are heated to become electrode active materials having a lattice constant larger than that of the electrode active material particles A coating step of coating a current collector on at least a part of the current collector to form a coating film;
A method for producing a positive electrode plate for a non-aqueous electrolyte secondary battery, comprising heating the coating film at a temperature equal to or higher than a temperature at which the metal element-containing compound becomes the electrode active material.   7. The metal element-containing compound according to claim 6, wherein at least one metal salt containing a metal selected from cobalt, nickel, manganese, iron, and titanium and a lithium salt are used. The manufacturing method of the positive electrode plate for non-aqueous-electrolyte secondary batteries of description. A storage case; a non-aqueous electrolyte secondary battery including a positive electrode terminal and a negative electrode terminal; and a protection circuit having an overcharge and over-discharge protection function, wherein the storage case includes the non-aqueous electrolyte secondary battery and the In a battery pack configured to contain a protection circuit,
The battery pack, wherein the non-aqueous electrolyte secondary battery is the non-aqueous electrolyte secondary battery according to claim 5.

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