JP2012089275A - Electrode plate for nonaqueous electrolyte secondary battery, manufacturing method of electrode plate for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery, and battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode plate for a nonaqueous electrolyte secondary battery having an excellent input and output characteristics, a manufacturing method of the electrode plate, a nonaqueous electrolyte secondary battery using the electrode plate, and a battery pack.SOLUTION: An electrode plate for a nonaqueous electrolyte secondary battery includes a collector and an electrode active material layer formed on at least a part of the surface of the collector, and the electrode active material layer includes an active material particle and a binder material including a crystalline metal nitride and a carbon component.

Description

  The present invention relates to an electrode plate used for a non-aqueous electrolyte secondary battery, a method for producing the electrode plate, a non-aqueous electrolyte secondary battery using the electrode plate, 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 has a memory effect during charging / discharging (when the battery is charged before it is completely discharged, Since there is no phenomenon in which the capacity decreases, it is used in various fields such as portable devices and large devices.

At present, efforts are being made to reduce CO ₂ emissions on a global scale. Plug-in hybrids that can greatly contribute to CO ₂ reduction by reducing the dependence on oil and enabling driving with low environmental impact. There is an urgent need to develop and spread next-generation clean energy vehicles such as automobiles and electric cars. Driving power that does not depend on gasoline is essential for the development and popularization of these next-generation clean energy vehicles. Non-aqueous electrolyte secondary batteries represented by lithium ion secondary batteries are expected as the driving force.

  The non-aqueous electrolyte secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and an organic electrolyte. And as said positive electrode plate and negative electrode plate, what equips the collector surface, such as metal foil, with the electrode active material layer formed by apply | coating an electrode active material layer forming liquid is generally used.

  The electrode active material layer forming liquid is composed of active material particles that can be charged / discharged by exhibiting lithium ion insertion / release reaction, resin binder, and conductive material (however, when the active material also exhibits a conductive effect) In some cases, the conductive material may be omitted), or, if necessary, other materials may be used and kneaded and / or dispersed in an organic solvent to prepare a slurry. Then, the electrode active material layer forming liquid is applied to the current collector surface, then dried to form a coating film on the current collector, and if necessary, an electrode plate having the electrode active material layer is manufactured by pressing. The method is general (for example, paragraphs [0019] to [0026] in Patent Document 1, paragraph 1 [Claim 1], paragraphs [0051] to [0055]).

  At this time, the active material particles contained in the electrode active material layer forming liquid are particulate compounds dispersed in the solution, and are fixed to the current collector surface only by being applied to the current collector surface. It is a difficult material. Accordingly, even when an electrode active material layer forming liquid not containing a resin binder is applied to a current collector and dried to form a coating film, the coating film is easily peeled off from the current collector. Therefore, an electrode active material layer in a conventional electrode plate is generally formed by fixing active material particles on a current collector through a resin binder, and the resin binder The material was essentially an essential constituent.

JP 2006-310010 A JP 2006-107750 A

  As described above, in recent years, lithium ion secondary batteries have been developed for fields that require high input / output characteristics such as electric vehicles, hybrid vehicles, and power tools. Also, secondary batteries used in relatively small devices such as mobile phones tend to be multifunctional. For this reason, the improvement of the input / output characteristic of the electrode plate for nonaqueous electrolyte secondary batteries is calculated | required.

  According to the study of the present inventor, the conventional electrode plate in which the active material particles are fixed on the current collector only with the resin binder is a factor that increases the electric resistance of the resin binder, and improves the input / output characteristics. I found out that it might be an obstacle.

  The present invention has been accomplished in view of the above circumstances. That is, the present invention provides an electrode plate for a non-aqueous electrolyte secondary battery having excellent input / output characteristics, a method for producing an electrode plate formed with such an electrode active material layer, and It aims at providing the nonaqueous electrolyte secondary battery and battery pack which use the said electrode plate.

  The present inventors have found that the active material particles can be fixed to the surface of the current collector by the presence of a binder containing a crystalline metal nitride and a carbon component to form an electrode active material layer, The present invention has been completed.

  In addition, as one means for fixing the active material particles on the current collector, the present inventors previously selected one or two or more metal nitride precursors capable of generating a metal nitride, and the metal After applying a solution containing a nitride precursor, active material particles, and, if necessary, an organic substance to the current collector surface, the metal nitride precursor is reacted to cause crystallinity on the current collector surface. And forming a binder material by forming a metal nitride of the above, and containing a carbon component in the binder material so that the active material particles can be fixed to the current collector surface via the metal nitride. The invention of the manufacturing method of the heading and the electrode plate for nonaqueous electrolyte secondary batteries was completed.

That is, the present invention
(1) A non-aqueous electrolyte secondary battery electrode plate comprising a current collector and an electrode active material layer formed on at least a part of the surface of the current collector, wherein the electrode active material layer comprises: A non-aqueous electrolyte containing active material particles and a binder, wherein the binder contains a crystalline metal nitride and contains a carbon component Secondary battery electrode plate,
(2) The electrode plate for a non-aqueous electrolyte secondary battery according to (1), wherein the metal nitride includes at least a Ti element,
(3) The electrode active material layer is characterized in that the active material particles are fixed to each other by the binding material and the active material particles are fixed to the current collector by the binding material. The electrode plate for a nonaqueous electrolyte secondary battery according to (1) or (2) above,
(4) Any of the above (1) to (3), wherein the electrode active material layer includes a portion where the crystal lattices are connected in a part of adjacent binder materials. The electrode plate for nonaqueous electrolyte secondary batteries as described in one.
(5) 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 an electrolyte containing a non-aqueous solvent, The non-aqueous electrolyte secondary battery, wherein the positive electrode plate and / or the negative electrode plate is the electrode plate for non-aqueous electrolyte secondary battery according to any one of (1) to (4) above. ,
(6) An electrode active material layer forming liquid containing at least active material particles, a metal nitride generating material for generating metal nitride, and an organic substance is applied to at least a part of the current collector. A coating step for forming a coating film and an electrode active material layer forming step are provided in this order. In the electrode active material layer forming step, the metal nitride generating material is reacted to form a crystalline metal nitride. And forming a binding material containing the metal nitride, and allowing the carbon component derived from the organic substance to remain in the binding material, whereby the binding material and the active material are formed on the current collector. A method for producing an electrode plate for a non-aqueous electrolyte secondary battery, characterized in that it is a step of forming an electrode active material layer containing particles,
(7) An electrode active material layer forming liquid containing at least active material particles and a metal nitride generating organic material for generating metal nitride is applied to at least a part of the current collector. A coating step for forming a coating film and an electrode active material layer forming step are provided in this order. In the electrode active material layer forming step, the metal nitride generating material is reacted to form a crystalline metal nitride. And forming a binding substance containing the metal nitride, and by allowing a carbon component derived from the metal nitride generating organic material to remain in the binding substance, the binder is bound on the current collector. A method for producing an electrode plate for a non-aqueous electrolyte secondary battery, characterized in that it is a step of forming an electrode active material layer containing an adhesion material and the active material particles,
(8) An electrode active material layer forming liquid containing at least active material particles, a metal nitride generating organic material for generating metal nitride, and an organic substance is formed on at least a part of the current collector. A coating step for coating to form a coating film and an electrode active material layer forming step are provided in this order. In the electrode active material layer forming step, the organic material for generating metal nitride is reacted to form a crystal. And forming a binding substance containing the metal nitride, and leaving the organic material for generating the metal nitride or the carbon component derived from the organic substance in the binding substance. A method for producing an electrode plate for a non-aqueous electrolyte secondary battery, wherein the electrode active material layer containing a binder and the active material particles is formed on the current collector,
(9) The electrode active material layer forming step is a heating step for heating the coating film, and the heating temperature in the heating step is set to the thermal decomposition start temperature of the metal nitride generating material or the metal nitride generating organic material. The temperature at which the carbon nitride in the organic material for forming metal nitride or the organic material remains in the binder is equal to or higher than the crystallization temperature of the metal nitride generated in the heating step. The method for producing an electrode plate for a nonaqueous electrolyte secondary battery according to any one of (6) to (8), wherein
(10) 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 are provided, and the nonaqueous electrolyte secondary battery is provided in the storage case. In the battery pack configured to house the battery and the protection circuit,
The non-aqueous electrolyte secondary battery includes at least a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, and an electrolyte solution containing a non-aqueous solvent. It is a secondary battery, and either one or both of the positive electrode plate and the negative electrode plate is the electrode plate for a non-aqueous electrolyte secondary battery according to any one of (1) to (4) above. Battery pack, characterized by
Is a summary.

  The electrode plate for a non-aqueous electrolyte secondary battery according to the present invention includes an active material particle fixed on a current collector with a binder containing a crystalline metal nitride and containing a carbon component. Thus, it is possible to provide an electrode plate for a non-aqueous electrolyte secondary battery that exhibits high input / output characteristics.

  Moreover, the electrode plate of this invention exhibits the advantageous effect that the softness | flexibility of an electrode plate improves and a processability improves by containing a carbon component in a binder.

  Moreover, according to the manufacturing method of the electrode plate for nonaqueous electrolyte secondary batteries of this invention, the electrode plate for nonaqueous electrolyte secondary batteries of this invention can be manufactured with an easy method and a general purpose material. it can.

  Further, the non-aqueous electrolyte secondary battery of the present invention and the battery pack of the present invention, in which the electrode plate of the present invention is used as a positive electrode plate and / or a negative electrode plate, are accompanied by improvement in the input / output characteristics of the electrode plate of the present invention. It is possible to improve the input / output performance of the non-aqueous electrolyte secondary battery itself and the input / output performance of the battery pack itself.

It is a schematic diagram which shows the cross section at the time of cut | disconnecting substantially perpendicular | vertical to the collector surface about the electrode plate for nonaqueous electrolyte secondary batteries of this invention. It is a schematic sectional drawing in one form of the lithium ion secondary battery of this invention. It is a schematic exploded view in one embodiment of the battery pack of this invention. 4A to 4D are schematic cross-sectional views illustrating exemplary embodiments of the current collector used in the present invention.

  Hereinafter, a nonaqueous electrolyte secondary battery electrode plate according to the present invention, a method for producing a nonaqueous electrolyte secondary battery electrode plate, and a nonaqueous electrolyte secondary battery, a mode for carrying out a battery pack, This will be explained in order. In the following description, a lithium ion secondary battery will be described as an example of the nonaqueous electrolyte secondary battery of the present invention unless otherwise specified.

[Electrode plate for non-aqueous electrolyte secondary battery]
FIG. 1 shows a schematic cross-sectional view of the electrode plate of the present invention. As shown in FIG. 1, the electrode plate 10 of the present invention is configured by providing an electrode active material layer 2 on at least a part of the surface of a current collector 1. In the electrode active material layer 2, active material particles are fixed on a current collector with a binder containing a crystalline metal nitride. As a result, it is possible to show very high input / output characteristics as compared with a conventional electrode plate that uses only a resin binder as a binder.

  In the description of the present invention, the term “fixed by a binding substance” includes the following two aspects. That is, the above-described fixing mode is between the objects to be fixed (for example, between the active material particles, between the active material particles and the current collector surface, or when using a conductive material, between the conductive material and the active material particles, When the metal nitride as the binder is interposed between the conductive material particles and the like (hereinafter referred to as “fixing mode 1”), the objects to be bonded are in direct contact with each other and surround the contact portion. And the case where the objects to be bonded are fixed together by the presence of the binding substance (hereinafter referred to as “fixing mode 2”). In many embodiments of the present invention, either one or both of the fixing modes 1 and 2 described above are present in the electrode active material layer. In particular, the sticking mode 2 tends to increase as the particle diameter of the active material particles and conductive material particles contained in the electrode active material layer decreases.

  In the case where the electrode active material layer is configured to include either or both of the fixing modes 1 and 2, the present invention exhibits an excellent effect in terms of improving the conductivity. In order to understand the above effect, attention is paid particularly to the adhesion between the conductive material particles in the electrode active material layer containing the conductive material particles. When the conductive material particles are fixed by the fixing mode 1, the binding material of the present invention is a metal nitride. Therefore, compared with the conventional resin binding material, the electron particles between the conductive material particles It is difficult to become an obstacle to interaction. In addition, in the embodiment of the present invention in which titanium nitride is selected as the metal nitride, since the nitride titanium itself also has good conductivity, it acts as a conductive bus that connects the conductive material particles. Contributes to the improvement of conductivity in the material layer. Furthermore, when the conductive material particles are fixed by the fixing mode 2, since the particles are in direct contact with each other, the flow of electrons is naturally smooth, and excellent conductivity is ensured. The input / output characteristics can be improved. The same can be said for the above-mentioned effect regarding the adhesion between the conductive material particles and the active material particles. In addition, even at the boundary between the current collector and the electrode active material layer, the current collector surface and the active material particles or the conductive material particles are fixed through the binder, or they are in direct contact with each other. Then, it is fixed by the presence of the binding substance around the contact portion. Therefore, the flow of electrons between the current collector and the electrode active material layer is smooth for the same reason as described above. That is, the electrode plate of the present invention has a binding material composed of a metal nitride present in the electrode active material layer, and various constituent materials are fixed by fixing modes 1 and / or 2. The electrical resistance can be kept low, and it is particularly preferable that the fixing modes 1 and 2 are mixed.

  In particular, the present invention has good film adhesion of the electrode active material layer to the current collector, and is excellent in cycle characteristics. The reason for this is not clear, but since the metal nitride, which is a binder, is crystalline, it can be deposited between active material particles, between active material particles and a current collector, or between conductive material particles. It is presumed that it is excellent in the force for fixing the objects together, and as a result, the durability of the electrode active material layer is improved and the cycle characteristics are improved.

  The above-mentioned fixed state can be observed, for example, with a scanning electron microscope at a magnification of about 10,000 to 100,000 times.

  In addition, the electrode plate of the present invention relates to the binding material contained in the electrode active material layer, and may include a portion where at least a part of the adjacent binding materials are connected by a continuous crystal lattice. Good. As described above, the binder material in the present invention is for fixing the active material particles on the current collector. At this time, in the present invention, it was speculated that the film adhesion of the electrode active material layer was further improved by the crystal lattices being continuous with each other in at least a part of the binding materials. This improvement in film adhesion is considered to contribute effectively to the improvement in the input / output characteristics of the electrode plate. From the viewpoint of improving the film adhesion of the electrode active material layer, it is more desirable that the portion where the crystal lattices of adjacent binder materials are continuous is significantly present in the electrode active material layer. In the present invention, whether or not the crystal lattices of the binder materials are continuous can be confirmed by observing the crystal lattice in the cross section of the adjacent binder materials in the electrode active material layer with a transmission electron microscope.

  In order to configure the electrode active material layer of the present invention so as to include a portion where crystal lattices in adjacent binder materials are continuous, it is desirable to manufacture the electrode plate of the present invention according to the manufacturing method of the present invention described later. . 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, on the current collector, the metal element-containing compound present around the active material particles undergoes a reaction such as thermal decomposition and oxidation, and a metal nitride as a binding material is generated around the active material particles. Is done. At this time, if a part of metal nitrides (or precursors thereof) constituting adjacent binders are bonded, the crystal growth of both is likely to proceed simultaneously at the bonded portion. As a result of the simultaneous crystal growth in the joint portion, the electrode active material layer of the present invention is configured to include a portion where crystal lattices in adjacent binder materials are continuous.

  The electrode plate of the present invention can be used as either a positive electrode plate or a negative electrode plate of a non-aqueous electrolyte secondary battery, or the electrode plate of the present invention may be used for both the positive electrode plate and the negative electrode plate.

  When the electrode plate of the present invention is used as a positive electrode plate, the input / output performance is higher than when only the resin binder is used. Furthermore, the electrode plate of the present invention is preferable because it can be used in combination with a conventional negative electrode plate.

  Moreover, when using the electrode plate of this invention as a negative electrode plate, the electrode plate of this invention is excellent at the point with the high input / output performance like the said positive electrode plate. In addition, the electrode plate of the present invention has excellent adhesion between a metal substrate such as copper or aluminum and a metal nitride, and further, a metal nitride film present around the negative electrode active material particles is SEI (Solid Electrolyte Interface). From the viewpoint of improving the cycle characteristics as a result.

  In particular, when the electrode plate of the present invention is used for both positive and negative electrodes, it can exhibit desirable effects such as improved input / output characteristics and improved cycle characteristics. In the following description, the present invention will be described as being divided into a positive electrode plate and a negative electrode plate as necessary. However, unless otherwise specified, the electrode plate of the present invention includes both the positive electrode plate and the negative electrode plate. In addition, the term “active material particles” is used in the meaning including both positive electrode active material particles and negative electrode active material particles.

Hereinafter, the method for evaluating charge / discharge rate characteristics of the electrode active material layer, the current collector, and the electrode will be described in order.

(Electrode active material layer)
The thickness of the electrode active material layer in the present invention can be appropriately designed in consideration of electric capacity and input / output characteristics required for the electrode plate. Generally, the thickness is designed to be 200 μm or less, more generally 100 μm or more and 150 μm or less. However, particularly in the present invention, since the electrode active material layer can be formed very thin, although depending on the particle diameter of the electrode active material particles used, the electrode active material layer having a film thickness of 300 nm to 200 μm. Can be formed. From the viewpoint that a high capacity can be obtained while improving the input / output characteristics, it is particularly preferable that the thickness of the electrode active material layer be 300 nm or more and 100 μm or less.

  When the thickness of the electrode active material layer is thin as in the above range, the electrode active material particles used have a small particle diameter, and are at least a particle diameter equal to or smaller than the film thickness of the electrode active material layer. This means that this greatly contributes to the improvement of the input / output characteristics. In addition, when the electrode active material layer is thin as described above, the moving distance of the electrons moving between the electrode active material particles and the current collector in the electrode active material layer is shortened. This is desirable because the resistance can be lowered, and as a result, the input / output characteristics can be improved. In the present invention, the lower limit of the film thickness of the electrode active material layer mainly depends on the particle diameter of the electrode active material particles to be used. It is possible to make the film thickness thinner than the range.

  Further, the electrode active material layer preferably has voids to the extent that the electrolytic solution can permeate, and the porosity in the electrode active material layer is generally 15 to 40%, more preferably 20 to 40%. It is. Below, the substance contained in the electrode active material layer in this invention is demonstrated concretely.

Active material particles:
The positive electrode active material particles contained in the electrode active material layer in the positive electrode plate of the present invention may be active material particles that exhibit a lithium ion insertion / release reaction generally used in positive electrode plates for non-aqueous electrolyte secondary batteries. There is no particular limitation. The above Examples of the positive electrode active material, for example _{LiCoO 2, LiMn 2 O 4,} LiNiO 2, LiFeO 2, LiTiO 2, LiFePO 4 and the like lithium composite oxides such as. In addition, as the negative electrode active material particles contained in the electrode active material layer in the negative electrode plate of the present invention, active material particles generally exhibiting lithium ion insertion and desorption reactions used in negative electrode plates for non-aqueous electrolyte secondary batteries If it is, it will not be specifically limited. Specific examples of the negative electrode active material include active material particles made of carbonaceous material such as natural graphite, artificial graphite, amorphous carbon, carbon black, or those obtained by adding different elements to these components, or Li _4. Examples thereof include, but are not limited to, a material that exhibits an insertion / release reaction of lithium ions, such as a compound containing metallic lithium such as Ti ₅ O ₁₂ , tin, silicon, and alloys thereof.

  The particle diameter of the active material particles used in the present invention is not particularly limited, and those having an arbitrary size can be appropriately selected and used. In particular, according to the present invention in which active material particles having a small particle diameter are used, the total amount of the surface area of the active material particles in the electrode active material layer can be increased, and lithium in one active material particle can be increased. Since the moving distance can be shortened, the input / output characteristics can be dramatically improved. Therefore, when a higher input / output characteristic is required, it is desirable to select one having a small particle size. Specifically, the particle diameter of the active material particles to be used is preferably less than 10 μm, more preferably 5 μm or less, and particularly preferably 1 μm or less. In a conventional slurry-like electrode active material layer forming liquid using a resin binder, when the active material particle diameter used is less than 10 μm, the coating suitability tends to be poor, and when it is 5 μm or less, the formation is performed. The fluidity of the liquid is remarkably deteriorated, making it difficult to apply to mass production equipment such as a printing press. Further, if it is 1 μm or less, it tends to be difficult to disperse the active material particles in the forming liquid. On the other hand, when manufacturing this invention, since the above problems are avoided, the particle diameter of an active material particle can be selected arbitrarily. The particle size of the active material particles shown in the present invention and the present specification is an average particle size (volume median particle size: D50) measured by laser diffraction / scattering particle size distribution measurement.

  The particle diameter of the active material particles contained in the electrode active material layer is a plurality of particle sizes arbitrarily selected from image observation results using image analysis type particle size distribution measurement software (manufactured by Mount Tech Co., Ltd., MAC VIEW). For example, it can be obtained by measuring the longest diameter of about 10 particles) and calculating the average value.

Metal nitride contained in the binder:
The metal nitride contained as a binder in the electrode active material layer is a compound containing at least a nitrogen element and a metal element, and is a crystalline metal nitride, and an active material on the surface of the current collector There is no particular limitation as long as the particles can be fixed.

  The metal element is not particularly limited. For example, specifically, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr Nitride containing any one or two or more metal elements selected from the group consisting of Nb, Mo, In, and Sn is included in the electrode active material layer as the metal nitride of the present invention. Can do.

  More specifically, magnesium nitride, aluminum nitride, silicon nitride, calcium nitride, titanium nitride, nickel titanium nitride, vanadium nitride, chromium nitride, manganese nitride, iron nitride, cobalt nitride, nickel nitride, copper nitride, zinc nitride, Examples of the metal nitride include gallium nitride, rubidium nitride, strontium nitride, yttrium nitride, zirconium nitride, niobium nitride, molybdenum nitride, indium nitride, and tin nitride.

  Among these, metal nitrides containing titanium elements such as titanium nitride and nickel titanium nitride are preferable as the binding material. By including titanium in the metal nitride, the electrical resistance is low and the conductivity is close to that of the metal, so that the resistance of the electrode active material layer can be reduced.

The titanium nitride may be a metal nitride generally expressed as TiN, or in Ti _X N _Y , X is 0.8 to 1.2 and Y is 0.8 to 1.2. The composition ratio may be changed between. Alternatively, titanium nitrides having different composition ratios may be mixed in one electrode active material layer. Further, an arbitrary element may be substituted within a range in which a peak shift that can be determined to be titanium nitride by XRD occurs. More specifically, it is represented as Ti _1-Z M _Z N (Z is 0.01 to 0.3), and Ti and an arbitrary element M may be substituted. In addition, the binding material in the present invention includes a case where a part of the binding material which is titanium nitride is partially oxidized into titanium nitride partial oxide.

  In particular, among the metal nitrides containing titanium element, it is desirable that titanium nitride is the metal nitride in the present invention. Crystalline titanium nitride has an electric resistance value of 100 μΩcm or less and has very good conductivity. For reference, the electrical resistance value of a carbon material such as acetylene black, which is used as the conductivity in the electrode plate for a nonaqueous electrolyte secondary battery, is about 0.14 to 0.25 Ωcm. When the electrode active material layer in the present invention contains crystalline titanium nitride as the metal nitride constituting the binder material, the titanium nitride acts as a binder material and also acts as a conductive material. Can also be demonstrated. Therefore, the electrode plate of the present invention that provides an electrode active material layer containing crystalline titanium nitride as the metal nitride constituting the binder material has good conductivity. Alternatively, by adding crystalline titanium nitride as a metal nitride constituting the binder material in the electrode active material layer, the present invention can suppress the amount of conductive material added, and as a result, per unit area Electrode capacity can be increased. The electrical resistance value can be measured using a resistivity meter Loresta.

  Further, in the electrode active material layer containing titanium nitride as the metal nitride constituting the binder material, when oxygen is released from the active material particles due to overcharge, nitriding is performed by at least a part of the oxygen. Titanium is partially oxidized. Therefore, the amount of oxygen derived from the active material particles can be reduced to the outside of the electrode active material layer, and the safety of the electrode plate, in turn, the safety of the battery or battery pack using the electrode plate can be reduced. Can be increased.

  Furthermore, when titanium nitride is selected as the metal nitride constituting the binder material in the present invention, the titanium nitride is a crystalline metal nitride. The present invention including an electrode active material layer including a binder material composed of crystalline titanium nitride is more conductive than an electrode plate including an electrode active material layer including amorphous titanium nitride as a binder material. Excellent.

  Moreover, in this invention, the metal nitride mentioned above can be contained in an electrode active material layer by 1 type, or 2 or more types of combination. In addition, the example of the metal nitride described above does not limit the metal nitride in the present invention at all. In the present invention, the metal nitride constituting the binding material of the active material particles on the current collector and Is a crystalline metal nitride, as long as it can fix the active material particles on the current collector. The binder material of the present invention may contain, for example, a metal or a metal oxide other than the metal nitride.

Mixing ratio of metal nitride contained in binder:
In the present invention, the mixing ratio of the metal nitride and the active material particles in the electrode active material layer is not particularly specified, and the type and size of the active material particles used, the type of metal nitride, and the function required for the electrode It can be determined as appropriate in consideration of the above. However, in general, the larger the amount of active material particles in the electrode active material layer, the higher the electric capacity of the electrode. From this point of view, the metal relative to the active material particles present in the electrode active material layer It can be said that a smaller amount of nitride is preferable.

  More specifically, in the electrode active material layer, when the weight ratio of the active material particles is 100 parts by weight, the weight ratio of the metal nitride is 1 part by weight or more and 50 parts by weight or less. Can do. If it is less than 1 part by weight, the active material particles may not be satisfactorily fixed on the current collector.

  On the other hand, the description of the upper limit of the weight ratio of the metal nitride is not intended to exclude the presence of the metal nitride exceeding the upper limit in the present invention. This shows that the active material particles can be fixed on the current collector with a smaller amount of metal nitride in order to increase the electric capacity of the electrode.

Regarding the crystallinity of the metal nitride contained in the binder:
The metal nitride in the present invention is specified to be crystalline. In the present invention, the crystalline metal nitride means a case where the metal nitride or a sample containing the metal nitride is analyzed by an X-ray diffractometer and the peak of the metal nitride is detected. For example, when titanium nitride is crystalline, when the X-ray diffraction result is viewed on a chart showing the intensity on the vertical axis and the 2θ angle on the horizontal axis, it is around 36 degrees, around 41 degrees, 61 degrees on the horizontal axis. Although a nearby peak is confirmed, the above-mentioned peak is not confirmed in amorphous titanium nitride, and it is determined whether it is crystalline or amorphous.

Carbon components contained in the binder:
The binder material in the present invention contains a carbon component. The carbon component contained in the binder in the present invention is a carbon component present in the binder, and a carbon-containing additive component such as a conductive material optionally added, or a negative electrode using the carbon material The active material particles are excluded. The carbon component contained in the binder material described above is contained in the active material as a polymer material, a decomposition product of the polymer material, a carbon element-containing compound, or carbon simple substance. Examples of the decomposition product of the polymer substance include, but are not limited to, an ether group-containing compound, an ester group-containing compound, a carboxyl group-containing compound, an acetylene compound, a cellulose compound, or a mixture thereof.

  The presence of the carbon component contained in the binder material is generally determined by the amount of carbon element detected by the compositional analysis of the electrode active material layer in the obtained electrode plate being the amount of carbon element derived from the electrode active material or conductive material. It can be confirmed whether it is more than the sum of. However, when the amount of the carbon component contained is very small, the amount of the carbon component may not be reflected in the composition analysis. Even in such a small amount of carbon component, it can be confirmed that the binder material contains the carbon component by element mapping described later.

  The carbon component is derived from carbon in a substance added to the electrode active material layer forming liquid, such as an organic substance or an organometallic compound described later. These are contained in the binder material by adjusting the heating temperature in the heating step so that it can remain as a carbon component in the binder material formed in the electrode active material layer in the production of the electrode plate of the present invention. Can be made. However, the method for incorporating the carbon component into the binder is not limited to this.

  In order to provide the electrode active material layer of the electrode plate of the present invention as a binding material containing a carbon component, for example, it includes an organic material or an organic material for generating a metal nitride capable of providing a carbon component, and a conductive material or The electrode active material layer forming liquid before adding a carbon material such as negative electrode active material particles composed of graphite is applied onto a substrate to form a coating film, and heated at an appropriate heating temperature or an appropriate heating atmosphere, etc. Thus, a preliminary experiment is carried out to confirm in advance that the carbon component is present in the formed layer. Next, an electrode active material layer forming liquid containing a necessary material is applied onto a current collector, and an electrode active material layer forming step such as a heating step is performed under the same conditions as in the preliminary experiment. In addition, an electrode plate including a binding material containing a carbon component other than a carbon material such as negative electrode active material particles composed of graphite can be manufactured. In the electrode plate obtained as described above, it is understood that carbon components other than carbon constituting the conductive material remain in the binder material regardless of the result of the composition analysis of the electrode active material layer.

  In order to confirm more specifically whether or not a carbon component is contained in the binding substance, a transmission electron microscope is used, and an EDX detector is used by scanning transmission electron microscopy (STEM method). Carbon elements can be confirmed by element mapping shown by nano-order elemental analysis. Alternatively, the carbon component contained in the binder can be confirmed by nano-order state evaluation using an EELS spectrometer and obtaining a composition contrast image using a HAADF detector. More specifically, in observation of an electron micrograph, in the electrode active material layer in the present invention, a binding material for fixing active material particles or the like is present between active material particles or around active material particles. Can be observed. And according to the method using the element mapping or the composition contrast image, it is possible to confirm the carbon component content by confirming the carbon elements scattered in the binder. Further, the carbon component is observed as a carbon element having a remarkably small scale, unlike graphite particles and conductive materials, which are confirmed as the presence of concentrated carbon atoms by the same method. Is clearly distinguished.

  In the present invention, a carbon component having a small scale that is clearly distinguished from the graphite particles and the conductive material may be further present in the electrode active material layer outside the metal nitride that is the binder. .

  In the present invention, the amount of the carbon component in the binding substance is not particularly limited, and even if the content of the carbon plate is not reflected in a general composition analysis, the input / output characteristics of the electrode plate. As described above, it can contribute to the improvement. For example, in the present invention, the carbon component contained in the binder material preferably contains 10 mol% or more of the carbon component with respect to 100 mol% of the metal element contained in the metal nitride. The upper limit is not particularly limited, but a content of 50 mol% or less can sufficiently contribute to improvement of cycle characteristics and reduction of volume resistance.

(Other materials)
The electrode active material layer can be composed only of the above-mentioned active material particles and the metal nitride constituting the binder and the carbon component contained in the binder, but does not depart from the spirit of the present invention. In the range further additives may be included. For example, the electrode plate of the present invention can exhibit good conductivity without using a conductive material, but when better conductivity is desired or the content of active material particles is increased. For example, it is desirable to use a conductive material.

  As the conductive material, those usually used for electrode plates for non-aqueous electrolyte secondary batteries can be used, and examples thereof include carbon materials such as acetylene black and carbon black such as ketjen black. It is not limited to. The average particle size of the conductive material is preferably about 20 nm to 50 nm. Carbon fiber (VGCF) is known as a different conductive material. The average particle diameter is obtained by an arithmetic average obtained from actual measurement using an electron microscope, as in the method of measuring the particle diameter of the active material particles.

  In the case where the conductive material is contained in the electrode active material layer, the content is not particularly limited, but in general, with respect to 100 parts by weight of the active material particles or 100 parts by weight of the total amount of the active material particles and the binding material. Thus, it is desirable that the ratio of the conductive material be 5 parts by weight or more and 20 parts by weight or less.

  In the present invention, the active material particles can be fixed on the current collector without using a resin binder, but this prohibits the resin component from being contained in the electrode active material layer. It is not the purpose. For example, when assembling a battery using an electrode plate, it is necessary to immerse the electrolyte into the pores of the electrode. At this time, in order to improve the permeability of the electrolyte, a resin is contained in the electrode active material layer. The component may be contained in an amount of 1 to 10%. Thus, if necessary, a small amount of resin material may be contained in the electrode active material layer in the present invention. Alternatively, as the binder, in addition to the metal nitride, a resin binder may be contained in the electrode active material layer.

(Current collector)
The current collector used in the present invention is generally used as a positive electrode current collector in a positive electrode plate for a non-aqueous electrolyte secondary battery or a negative electrode current collector in a negative electrode plate for a non-aqueous electrolyte secondary battery. There is no particular limitation. For example, the current collector is preferably made of a single element such as an aluminum foil, nickel foil, or copper foil or an alloy, or a highly conductive foil such as a carbon sheet, carbon plate, or carbon textile. It is done. The current collector used in the present invention may be a current collector that has been subjected to surface processing on the surface on which the electrode active material layer is to be formed, if necessary. Examples of the current collector that has been subjected to surface processing treatment include those in which a conductive material is laminated, surface treatments such as chemical polishing treatment, corona treatment, and oxygen plasma treatment. Alternatively, the current collector may be physically provided with any unevenness on the surface.

  As the current collector, for example, as shown in FIG. 4A, the current collector 1 used for the electrode plate 20 for a non-aqueous electrolyte secondary battery has a current collecting base such as a metal foil itself having a current collecting function. Only material 3 can be used. Examples of the current collecting base 3 include the above-described aluminum foil, nickel foil, carbon sheet, and the like. In such a case, the electrode active material layer 2 is provided on at least a part of the surface of the current collecting base material 3.

  In addition, as an example of a different current collector, as shown in FIG. 4B, a current collector 1 itself having a current collecting function is used as the current collector 1 ′ used for the electrode plate 20 ′ for the nonaqueous electrolyte secondary battery. A current collector 1 ′ in which an arbitrary conductive layer 4 having conductivity is provided on the upper surface of the material 3 can be used. The electroconductive layer 4 should just show electroconductivity of the grade which does not prevent the movement of the electron between the electrode active material layer 2 and the current collection base material 3. FIG. For example, the conductive layer 4 is a laminated layer made of copper or a copper alloy, a layer in which arbitrary conductive fine particles are deposited by plating or sputtering, or a layer in which one or more conductive thin films are provided. However, the present invention is not limited to these examples. In the current collector 1 ′, the surface of the conductive layer 4 becomes the surface 102 of the current collector 1 ′, and the electrode active material layer 2 is provided on at least a part of the surface 102. FIG. 4B shows a mode in which the arbitrary conductive layer 4 is one layer. However, the configuration of the current collector 1 ′ is not limited to this, and the conductive layer 4 may have a stacked configuration in which two or more arbitrary conductive layers are stacked.

  Further, as an example of a different current collector, as shown in FIG. 4C, a current collector 1 ″ used for the electrode plate 20 ″ for a nonaqueous electrolyte secondary battery itself has a current collecting function. A current collector in which an arbitrary intermittent layer 5 formed intermittently is provided on the upper surface of the electric substrate 3 can be used. The intermittent layer 5 may be a conductive layer similar to the conductive layer 4 described above, or may be a layer that does not exhibit conductivity. That is, in the electrode plate 20 ″ for the non-aqueous electrolyte secondary battery, the surface 103 of the current collector 1 ″ of the electrode active material layer 2 is provided with the surface 103 that is the surface of the intermittent layer 5 and the intermittent layer 5. And the surface 103 ′ which is the surface of the current collecting base 3 itself. At this time, the electrode active material layer 2 can be formed so as to be in contact with both the surface 103 and the surface 103 ′. In the electrode plate 20 ″ for a nonaqueous electrolyte secondary battery, the intermittent layer 5 may or may not have conductivity. Even if the intermittent layer 5 is a non-conductive layer, the electrode active material layer 2 is in direct contact with the current collector base 3 on the surface 103 ′ of the current collector 1 ″. And the current collector 1 ″ ensure the movement of electrons. However, from the viewpoint of reducing the electrical resistance of the negative electrode plate 20 ″ for the nonaqueous electrolyte secondary battery itself, it is preferable that the intermittent layer 5 also exhibits conductivity.

  Further, when the intermittent layer 5 exhibits conductivity, as shown in FIG. 4D, an electrode active material layer 2 ′ is selectively provided only on the intermittent layer 5 on the surface of the current collector 1 ″. You may comprise electrode board 20 '' 'for nonaqueous electrolyte secondary batteries. That is, the electrode active material layer 2 ′ may be selectively provided on at least a part of the surface 103 of the surface of the current collector 1 ″. Alternatively, although not shown, when the intermittent layer 5 does not exhibit conductivity, the electrode active material layer 2 ′ may be selectively provided on at least a part of the surface 103 ′ of the current collector 1 ″.

  The description of the current collector described above does not limit the current collector used in the present invention. As exemplified above, the current collector used in the present invention may be only a current collecting substrate having a current collecting function in the present invention. In such an embodiment, the electrode active material layer is The surface of the current collector provided refers to the surface of the current collector substrate. Alternatively, in the present invention, the current collector may have a current collecting base material having a current collecting function and an arbitrary laminated layer provided on the current collecting base material. In such an embodiment, the surface of the current collector on which the electrode active material layer is provided is within the range in which the movement of electrons is ensured in at least one region between the current collector base material and the electrode active material layer. It refers to the surface, or the surface of the current collecting base material on which the laminated layer is not provided, or the surface of the current collecting base material on which the surface of the laminated layer is not provided.

  As the current collector used in the present invention, one having a heat resistant temperature of 800 ° C. or lower, further 600 ° C. or lower, and particularly 400 ° C. or lower can be selected. The selection of the current collector is determined by the relationship with the temperature condition in the electrode active material layer forming step in the production method of the present invention described later. In the manufacturing method of this invention, when an electrode active material layer formation process is a heating process, an electrode active material layer can be directly formed on a collector at the heating temperature of 400 degrees C or less, for example. Accordingly, the current collector can be selected to have a heat resistant temperature of 800 ° C. or lower, more preferably 600 ° C. or lower, and particularly 400 ° C. or lower, and an electrode active material layer is directly formed on the current collector. An electrode plate of the present invention can be provided.

  The thickness of the current collector is not particularly limited as long as it can be used as a current collector for a positive electrode plate or a negative electrode plate for a non-aqueous electrolyte secondary battery, but is preferably 10 to 200 μm. More preferably, it is 50 μm.

(Method for evaluating charge / discharge rate characteristics of electrode)
The input / output characteristics of the electrode plate of the present invention can be evaluated by determining the discharge capacity maintenance rate (%). That is, the discharge capacity retention rate is an evaluation of discharge rate characteristics, and it is understood that an electrode plate with improved discharge rate characteristics generally has improved charge rate characteristics as well. Therefore, when a desirable discharge capacity maintenance rate is indicated, it is evaluated that the charge / discharge rate characteristics have been improved. More specifically, the discharge rate 1C is set so that the theoretical value of the discharge capacity (mAh / g) of the active material is completed in 1 hour, and the discharge actually measured at the set discharge rate of 1C. The capacity (mAh / g) is set to a discharge capacity maintenance rate of 100%. Then, the discharge capacity (mAh / g) when the discharge rate is further increased is measured, and the discharge capacity retention ratio (%) can be obtained by the following equation (1). In addition, the said discharge capacity is calculated | required by measuring the discharge capacity of electrode itself with a tripolar coin cell.

[Method for producing electrode plate for non-aqueous electrolyte secondary battery]
Next, a method for producing the 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. In the production method of the present invention, when producing a positive electrode plate, the electrode active material layer forming liquid contains positive electrode active material particles and a positive electrode active material layer in order to form a positive electrode active material layer on a current collector. In the case of adding a suitable metal nitride precursor and manufacturing a negative electrode plate, the negative electrode active material layer forming liquid contains negative electrode active material particles in order to form a negative electrode active material layer on the current collector. And a metal nitride precursor suitable for this. However, in the method for producing the electrode plate of the present invention, “positive electrode” and “negative electrode” may be collectively referred to as “electrode”.

  The production method of the present invention comprises preparing an electrode active material layer-forming liquid containing a metal nitride precursor and applying the solution on a current collector to form a coating film. An electrode active material layer forming step for forming the material layer is provided in this order. The active material particles and arbitrary conductive material particles contained in the electrode active material layer forming liquid are in a state in which the direct contact between the particles is well maintained as shown as the fixing mode 2 in addition to the fixing mode 1. A mode of being fixed is included. As described above, the factors that enable the fixing state shown in fixing modes 1 and 2 are that the metal nitride precursor is dissolved in the electrode active material layer forming liquid in the manufacturing method of the present invention, and that The electrode active material layer forming liquid mixed with the material particles is applied onto the current collector, the solvent is removed by an appropriate means, and the metal nitride (binding material) generated when the electrode active material layer is formed. ) Is presumed to be generated between the particles or around the contact portion where the particles directly contact each other. As a result, the manufacturing method of the present invention can manufacture an electrode plate that has good conductivity and can keep electric resistance low.

  Unlike a slurry-like electrode active material layer forming liquid using a conventional resin binder, the metal nitride precursor and active material used in the method for producing an electrode plate for a non-aqueous electrolyte secondary battery of the present invention The electrode active material layer forming liquid prepared by containing particles has a viscosity that can maintain good applicability to the current collector regardless of the particle diameter of the active material particles contained. Therefore, in the conventional electrode active material layer forming liquid, the active material particles having a small particle diameter, which has been difficult to use due to a significant improvement in viscosity, are used in the method for producing an electrode plate for a non-aqueous electrolyte secondary battery of the present invention. It can be used now. In addition, the method for producing an electrode plate for a non-aqueous electrolyte secondary battery according to the present invention can be applied to a desired thickness because the electrode active material layer forming liquid has good applicability to the current collector. Thus, the electrode active material layer can be made thin.

  Further, according to the method for producing an electrode plate for a non-aqueous electrolyte secondary battery of the present invention, the use of active material particles having a small particle diameter, which is an approach to improving the input / output characteristics of the electrode plate, and the electrode active material Any of these thinning methods can be easily realized. More specifically, it has a desirable feature that the viscosity of the active material particles does not increase so much that the coatability is reduced even when the active material particles have a particle size of 10 μm or less, and even 1 μm or less. ing. Therefore, a desired size can be selected for the particle diameter of the active material particles used. As described above, according to the production method of the present invention, non-aqueous electrolysis with improved input / output characteristics by using active material particles having a small particle diameter or by designing the thickness of the electrode active material layer to be small. The electrode plate for a liquid secondary battery can be easily manufactured.

  Below, the three aspects for manufacturing the electrode plate of this invention are demonstrated. The metal nitride precursor is a material contained in the electrode active material layer forming liquid to generate the metal nitride constituting the binder, and is, for example, a metal nitride generating material or a metal Nitride-generating organic materials are exemplified. A metal nitride-forming organic material is distinguished from a metal nitride-generating material that does not contain carbon in that it contains carbon.

  A first aspect of the production method of the present invention is to prepare an electrode active material layer forming liquid containing at least active material particles, a metal nitride generating material for generating metal nitride, and an organic material. , The coating step and the electrode active material layer forming step described later are sequentially performed. Then, the metal nitride producing material is reacted to produce crystalline metal nitride, forming a binding substance containing the metal nitride, and containing the organic carbon component in the binding substance. By remaining, an electrode active material layer containing a binder and the active material particles is formed on the current collector.

  A second aspect of the production method of the present invention is to prepare an electrode active material layer forming liquid containing at least active material particles and a metal nitride generating organic material for generating metal nitride, , The coating step and the electrode active material layer forming step described later are sequentially performed. Then, the metal nitride producing material is reacted to produce a crystalline metal nitride, forming a binder containing the metal nitride, and a carbon component derived from the metal nitride producing organic material. An electrode active material layer containing the binding material and the active material particles is formed on the current collector by remaining in the binding material.

  A third aspect of the production method of the present invention is to prepare an electrode active material layer forming liquid containing at least active material particles, a metal nitride generating organic material for generating metal nitride, and an organic material. And using this, the coating process mentioned later and the electrode active material layer formation process are carried out in order. Then, the metal nitride generating organic material is reacted to generate a crystalline metal nitride, forming a binder containing the metal nitride, and the metal nitride generating organic material or the organic material An electrode active material layer containing the binding material and the active material particles is formed on the current collector by leaving the derived carbon component in the binding material.

  In any of the first to third aspects described above, one point to be noted in the preparation of the electrode active material layer forming liquid is that a carbon such as an optionally added conductive material or graphite particles added as active material particles. It is a material other than the active material particles of the system, in which an organic material for producing metal nitride and / or an organic substance is blended as a carbon-containing material, and the carbon component can remain in the produced binder material. is there.

  In addition to the above three aspects, for example, as a metal nitride precursor, one or more metal element-containing compounds and one or more organic metal compounds are combined to form an electrode active material layer forming liquid. You may make it contain.

Active material particles:
Since the active material particles contained in the electrode active material layer forming liquid are the same as the active material particles already described above, the description thereof is omitted here. In addition, in the manufacturing method of this invention, the particle diameter of the active material particle used can select a desired magnitude | size similarly to the above-mentioned.

Metal nitride precursor:
In the production method according to the present invention, the metal nitride precursor contained in the electrode active material layer forming solution is coated on the substrate in a state dissolved in a solvent, and formed into a coating film by receiving an appropriate reaction means. Is a possible material. For example, when the heating means is selected as the reaction means, the metal nitride precursor is thermally decomposed and nitrided when heated on the substrate at a temperature equal to or higher than the thermal decomposition start temperature, and the metal nitride It is a material that can be formed into a film as a product. The inventors of the present invention include a metal nitride precursor and active material particles based on the idea of including active material particles in the binder material to be coated without using a resin binder. The solution to be prepared was prepared, applied on the current collector and tried to be heated. As a result, even if the amount of the binding material generated on the current collector is significantly reduced to such an extent that the metal nitride as the binding material exists in the electrode active material layer mainly composed of active material particles, the active material It has been found that the particles are fixed on the current collector.

  Accordingly, the metal nitride precursor used in the production method of the present invention is selected as long as it contains an element that can be nitrided and formed into a film without departing from the spirit of the present invention. May be.

  In the production method of the present invention, the electrode active material forming step such as a heating step is performed under a nitrogen atmosphere, an ammonia gas atmosphere, or a mixed gas atmosphere of an inert gas such as nitrogen gas or argon gas and ammonia gas. When implemented, a compound containing a metal element selected from a group of general metal elements can be used as a metal nitride forming material that is a metal nitride precursor. Specifically, the metal nitride precursor is 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, and Ce, any compound selected from the group consisting of general metal elements, or a compound containing two or more metal elements may be used.

  Although the reason is not clear, the electrode plate produced when a metal nitride producing material containing one or more metal elements belonging to 3 to 5 cycles among the above metal elements is used. This is preferable because the I / O characteristics tend to be higher.

  Moreover, as a metal nitride production | generation material containing the said metal element, a metal salt is used preferably, for example. Examples of the metal salt include chloride, nitrate, sulfate, perchlorate, phosphate, bromate and the like. Among these, in the present invention, chlorides and nitrates are preferably used because they are easily available as general-purpose products. In particular, nitrate is preferably used because it is inexpensive.

  Specific examples of the metal salt include magnesium chloride, aluminum nitrate, aluminum chloride, calcium chloride, titanium tetrachloride, vanadium oxosulfate, ammonium chromate, chromium chloride, ammonium dichromate, chromium nitrate, chromium sulfate, nitric acid. Manganese, manganese sulfate, iron chloride (I), iron chloride (III), iron nitrate (III), iron sulfate (II), ammonium iron sulfate (III), cobalt chloride, cobalt nitrate, nickel chloride, nickel nitrate, copper chloride, Copper nitrate, zinc chloride, zinc chloride, yttrium nitrate, yttrium chloride, zirconium chloride, zirconium nitrate, zirconium tetrachloride, silver chloride, indium nitrate, tin sulfate, cerium chloride, cerium nitrate, diammonium cerium nitrate, cerium sulfate, Samarium chloride and nitrate nitrate , Lead chloride, lead nitrate, lead iodide, lead phosphate, lead sulfate, lanthanum chloride, lanthanum nitrate, gadolinium nitrate, strontium chloride, strontium nitrate, niobium pentachloride, ammonium molybdate phosphate, molybdenum sulfide, palladium chloride, Palladium nitrate, antimony pentachloride, antimony trichloride, antimony trifluoride, telluric acid, barium sulfite, barium chloride, barium chlorate, barium perchlorate, barium nitrate, tungstic acid, ammonium tungstate, tungsten hexachloride, pentachloride Examples include tantalum, hafnium chloride, and hafnium sulfate.

  On the other hand, when an electrode active material layer forming step such as a heating step is performed in an atmosphere that does not sufficiently contain nitrogen gas or ammonia gas, an ammonium salt containing a metal element or the like is used as a metal nitride generating material. Preferably used. Specifically, magnesium ammonium phosphate hexahydrate, ammonium aluminum sulfate, iron (III) ammonium citrate, ammonium iron (II) sulfate hexahydrate, ammonium hexafluorosilicate, chromium (III) ammonium sulfate, hexafluoro Ammonium titanate, ammonium hexafluoroniobate (V), copper (II) ammonium sulfate hexahydrate, diammonium cobalt (II) sulfate hexahydrate, nickel (II) ammonium sulfate hexahydrate, manganese sulfate ( II) Ammonium hexahydrate, ammonium molybdophosphate n-hydrate, tetraammonium cerium sulfate (IV) tetrahydrate and the like are exemplified. Alternatively, in addition to the metal nitride forming material described above, an ammonium salt that does not contain a metal such as ammonium acetate, ammonium nitrate, or ammonium carbonate may be mixed.

  In addition, as the metal nitride precursor in the present invention, in particular, an organic material for generating metal nitride containing a carbon element can be used. The organic material for generating metal nitride is a compound containing any one kind or two or more kinds of metal elements and carbon selected from the group of general metal elements as listed in the above-mentioned metal nitride producing material If it is.

  Examples of organic materials for forming metal nitride include metal salts such as acetate and oxalate, or metal complexes such as magnesium diethoxide, aluminum acetylacetonate, and calcium acetylacetonate dihydrate. However, it is not limited to this.

  Alternatively, an ammonium salt such as ammonium acetate may be used as the organic material for generating metal nitride.

  Alternatively, as at least one of the metal nitride precursors, titanium tetraisopropoxide, titanium tetranormal butoxide, titanium butoxide dimer, titanium tetra-2-ethylhexoxide, titanium diisopropoxybis (acetylacetonate), titanium tetra Acetyl acetonate, titanium dioctyloxy bis (octylene glycolate), titanium diisopropoxy bis (ethyl acetoacetate), titanium diisopropoxy bis (triethanolaminate), titanium lactate ammonium salt, titanium lactate, and polyhydroxy One or more selected from the group consisting of titanium stearate may be used.

  In addition, even if it is other than the metal nitride precursor specifically illustrated above, the material which can be selected suitably and can become a metal nitride precursor in the range which does not deviate from the meaning of this invention can be used. That is, in the electrode active material layer provided on the electrode plate for a non-aqueous electrolyte secondary battery manufactured by the manufacturing method of the present invention, the active material particles are preferably binding materials that can be fixed on the current collector. Any material can be selected and used as long as it is a material capable of generating metal nitride.

organic matter:
In addition, as another compound for providing the carbon component remaining in the binder, an organic substance that is distinguished from the organometallic compound can be used. Specific examples of the organic substance include, for example, cellulose polymers such as methylcellulose and ethylcellulose, polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polyethylene-propylene glycol, polyethylene oxide, polypropylene oxide, acrylic resins, and urethane resins. And epoxy resin, phenol resin, melamine resin, polyvinyl acetate, polyethylene, polypropylene, polyether, starch, polyvinyl alcohol and the like. Some of these organic substances exhibit an effect of adjusting the viscosity when the electrode active material layer forming liquid is prepared. These organic substances are mixed in the electrode active material layer forming liquid, and after the application of the forming liquid on the current collector, an appropriate electrode active material layer forming process such as heating at an appropriate temperature is performed, thereby generating The carbon component can remain in the binding material.

  When the conductive material is added to the electrode active material layer forming liquid, the addition of the conductive material is performed with respect to 100 parts by weight of the total amount of the active material particles generated on the current collector surface and the metal nitride to be formed. The amount is desirably 5 to 20 parts by weight. In addition, the above is not the meaning which excludes adding a conductive material exceeding 20 weight. In particular, when titanium nitride is selected as the metal nitride, the amount of conductive material added can be 3% or less, preferably 1% or less due to the conductivity of titanium nitride. More preferably, substantially no conductive material may be used.

solvent:
The solvent used in the electrode active material layer forming liquid can be prepared as an electrode active material layer forming liquid to which active material particles, metal nitride precursors, or other additives are added, and a current collector. There is no particular limitation as long as it can be removed in the heating step after being coated thereon. For example, water, methanol, ethanol, isopropyl alcohol, propanol, butanol and other lower alcohols having a total carbon number of 5 or less, diketones such as acetylacetone, diacetyl, benzoylacetone, ethyl acetoacetate, ethyl pyruvate, ethyl benzoylacetate, benzoyl Examples thereof include ketoesters such as ethyl formate, one kind of solvent such as toluene, or a mixed solvent composed of a combination of two or more of these.

  The electrode active material layer forming liquid contains necessary amounts of active material particles, metal nitride precursors, and other additives added as necessary in the electrode active material layer that is scheduled to be formed on the current collector. These amounts are determined in consideration of the above. At that time, the solid content ratio is appropriately adjusted in consideration of applicability on the current collector in the coating step and removal of the solvent in the electrode active material layer forming step. Generally, it adjusts so that the solid content ratio in an electrode active material layer forming liquid may be 30-70 wt%.

Application process:
Next, an application process in which the electrode active material layer forming liquid prepared as described above is applied onto a current collector to form a coating film will be described. The current collector used in the production method of the present invention is the same as the current collector used in the electrode plate for a non-aqueous electrolyte secondary battery, and is omitted here.

In a coating process, if it is a well-known coating method as a coating method of an electrode active material layer forming liquid, it can select and implement suitably. For example, a coating film can be formed by applying 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 current collector surface 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 is preferable because corona treatment, oxygen plasma treatment, and the like can be performed in advance as necessary to further improve the film forming property of the electrode active material layer.

  The amount of the electrode active material layer forming liquid applied to the current collector can be arbitrarily determined according to the use of the electrode plate to be produced, etc., but the electrode active material layer in the present invention is very Since it can be formed thinly, when it is desired to reduce the film thickness, the electrode active material layer formed by a heating process described later can be thinly applied so that the thickness thereof is about 300 nm to 11 μm. As described above, by applying the electrode active material layer forming liquid to the current collector, the electrode active material layer forming coating film (hereinafter simply referred to as “coating”) containing at least the active material particles and the metal nitride precursor. A film is sometimes formed).

  A pressing step may be further performed between the coating step and the electrode active material layer forming step or after the electrode active material layer forming step. The said press process can be implemented by drying the said coating film for electrode active material layer formation formed on the electrical power collector as needed, removing a solvent, and pressing it after that. Therefore, when performing an electrode active material layer formation process after a press process, a part or all of the solvent in a coating film may be removed beforehand before this electrode active material layer formation process. The pressing method can be carried out in the same manner as the press performed by applying a slurry-like electrode active material layer forming liquid containing a conventional resin binder on the current collector and drying it. However, it is not limited to this. Thus, the manufacturing method of the present invention can adjust the porosity of the electrode active material layer in the finally manufactured electrode plate and increase the energy density per volume by performing the pressing step. .

Electrode active material layer formation process:
An electrode active material layer formation process is a process of forming an electrode active material layer from the coating film formed at the application | coating process. For example, as one aspect of the electrode active material layer forming step, the solvent contained in the coating film is removed, and the metal nitride precursor is reacted to form crystalline metal nitride. The binder material is constituted, the carbon component is left in the binder material, the active material particles are fixed on the current collector by the binder material, and the binder material and the above-described material are fixed on the current collector. It may be a step of forming an electrode active material layer containing active material particles.

  Alternatively, an electrode active material layer forming step may be performed after an arbitrary step such as a pressing step is provided between the coating step and the electrode active material layer forming step and the solvent in the coating film is removed. That is, in the electrode active material layer forming step, the metal nitride precursor contained in the coating film from which the solvent has been removed is reacted to form crystalline metal nitride to form a binder material, and An electrode containing a carbon component remaining in a binder, the active material particles fixed on the current collector by the binder, and the metal nitride and the active material particles on the current collector It may be a step of forming an active material layer.

  Examples of the electrode active material layer forming step include, but are not limited to, a heating step, a reduced pressure drying step, a reduced pressure heating step, or a combination thereof, and an electrode active material applied on a current collector. What is necessary is just the process of implementing the means which can form the coating film formed with the layer formation liquid as an electrode active material layer. For example, the electrode active material layer forming step may include two or more means such as a means for removing the solvent contained in the coating film and then a means for reacting the metal nitride precursor. Good. In addition, in the electrode active material layer forming step in which an arbitrarily selected means is implemented, a crystalline metal nitride constituting the binder material is generated, and a carbon component is contained in the binder material. , Adjust the implementation conditions.

  Below, the heating process which implements a heating means is demonstrated to an example about the electrode active material layer formation process for forming an electrode active material layer from the coating film formed in the said application | coating process. In the heating step, if necessary, the solvent in the coating film is removed, the metal nitride precursor present in the coating film is heated and thermally decomposed, and the crystalline metal containing the elements contained therein is included. This is done for the purpose of producing nitride.

  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 desired heating temperature, and can be appropriately selected and carried out. Specific examples include a method of using a hot plate, an oven, a heating furnace, an infrared heater, a halogen heater, a hot air blower, or the like, or a combination of two or more. When the current collector to be used is planar, it is preferable to use a hot plate or the like for the heating step. In addition, when heating using a hot plate, it is preferable to install and heat the coating film surface side in a direction not in contact with the hot plate surface.

  The heating temperature in the heating step is equal to or higher than the thermal decomposition start temperature of the metal nitride precursor, the generated metal nitride is higher than the crystallization temperature at which crystallinity is exhibited, and the organic material for generating metal nitride is used. Alternatively, the carbon component contained in at least one of the organic substances is determined within a temperature range in which the carbon component can remain as a carbon component in a binder material containing a metal nitride. The above heating temperature is preliminarily dissolved in a metal nitride precursor to be used, or a solution to which an organic substance is added is applied on an appropriate substrate and heated to produce a desired metal nitride. It may be determined as appropriate by confirming whether the metal nitride is crystalline, whether the metal nitride is crystalline, and whether a carbon component is contained in the binder. The heating in the preliminary test is performed in an atmosphere similar to the heating atmosphere planned in the manufacturing method.

That is, in the present invention, “the thermal decomposition start temperature of the metal nitride precursor” is understood as the temperature at which the metal nitride precursor is thermally decomposed by heating and the nitridation of the metal element contained therein starts. it can. In addition, regarding the temperature range in which the carbon component can remain in the binder material containing the generated metal nitride, the metal nitride-forming organic material and / or the solution used in the preliminary test is also used. It can be grasped by confirming whether or not carbon components remain in the produced laminated film by containing an organic substance.

  In the present invention, the “crystallization temperature” refers to a temperature at which the metal nitride is crystallized after the metal nitride is generated from the metal nitride precursor or the like contained in the electrode active material layer forming liquid. Means. The metal nitride crystallizes at the crystallization temperature, and the crystallinity increases when the temperature is exceeded. However, in the present invention, the term “crystallization” refers to the crystal state in the X-ray diffractometer regardless of the crystallinity. This refers to the case where the peak shown is confirmed.

  The “crystallization temperature” in the present invention does not necessarily match the intrinsic crystallization temperature of the metal nitride, and differs slightly from these intrinsic crystallization temperatures depending on the state in the electrode active material layer forming liquid. There is a case. Therefore, in consideration of this point, it is desirable to confirm the crystallization temperature of the metal nitride in the electrode active material layer-forming coating film in advance.

  On the other hand, the above-mentioned heating temperature is “below the crystallization temperature” of the metal nitride produced means that the metal nitride contained in the electrode active material layer formed on the current collector is in an amorphous state. It is a temperature that allows it to exist at. The temperature is preliminarily applied on the substrate with a solution containing the metal nitride precursor, heated at a temperature equal to or higher than the thermal decomposition start temperature of the metal nitride precursor, and made of metal nitride on the substrate. Form a film, scrape the film into a sample, evaluate the crystallinity using an X-ray diffractometer, and understand that if the crystal peak is not confirmed, it was heated at a temperature below the crystallization temperature. can do.

  Here, generally, when producing crystalline metal nitride, it is necessary to heat the coating film at a temperature of at least about 900 ° C. or higher. On the other hand, in the production method of the present invention, crystalline metal nitride is produced even at a low heating temperature of 800 ° C. or lower, further 600 ° C. or lower, particularly 400 ° C. or lower. This is one of the characteristic points of the manufacturing method. In particular, when the heating temperature is 400 ° C. or lower, the selection range of the current collector is widened, the electrode active material layer can be directly formed on various current collectors, and the working temperature is low. This is preferable because various effects such as an improvement in cost merit are exhibited. The crystalline metal nitride includes a microcrystalline state.

  In determining the heating temperature in the heating step, it is desirable to sufficiently take into account the heat resistance of the current collector, active material particles, conductive material, and the like used, and the heating atmosphere. For example, the heat resistant temperature of a copper foil generally used as a current collector for an electrode plate is about 200 ° C. because it is oxidized in an oxygen atmosphere, and about 1080 ° C. if it is an inert gas atmosphere, or This is because the heat resistance temperature of the aluminum foil is around 660 ° C., and therefore the current collector may be damaged when the heat resistance temperature is exceeded.

  The heating atmosphere in the heating step in the present invention is not particularly limited, but an inert gas atmosphere such as argon gas and nitrogen gas, a reducing gas atmosphere such as hydrogen gas and carbon monoxide gas, an ammonia gas atmosphere, and the like are appropriately selected. be able to. Moreover, the mixed gas which consists of two or more gas selected arbitrarily may be sufficient. In particular, when the metal nitride is generated, the amount of oxygen contained in the heating atmosphere is preferably 200 ppm or less, more preferably 100 ppm or less, and more preferably ammonia gas is contained in the heating atmosphere. For example, in an appropriate heating atmosphere, at least a part of the constituent elements of the thermally decomposed metal nitride precursor is nitrided with nitrogen in the atmosphere to generate a metal nitride. As another example, a heating step is performed under an inert gas atmosphere, and a metal nitride is generated by a nitrogen component contained in the metal nitride precursor.

  The electrode plate of the present invention may further contain a resin component in the electrode active material layer produced as described above. For example, the electrode active material layer may further contain a resin component by, for example, applying a resin mixed solution to the surface of the electrode active material layer or immersing an electrode plate in a resin mixed solution tank, A method of removing the solvent of the resin mixed solution impregnated in the electrode active material layer by infiltrating the gaps in the electrode active material layer and then drying, leaving only the resin component inside the electrode active material layer. Can be mentioned. Thus, if it is the electrode plate of this invention which contains a resin component in an electrode active material layer, the bending tolerance of an electrode plate will improve by presence of a resin component, and it can improve a process characteristic. In particular, when the resin component is a conventionally used resin binder, the film adhesion of the electrode active material layer to the current collector can be further improved.

  As the resin material contained in the resin mixed solution, for example, a conventional resin binder such as PVDF, styrene butadiene rubber (SBR), carboxymethoxy cellulose (CMC), or those listed in the viscosity modifier are selected. However, the present invention is not limited to this. The resin material is appropriately selected to have a size that can penetrate into the voids in the electrode active material layer. Examples of the solvent for the resin mixture include lower alcohols having a total carbon number of 5 or less such as methanol, ethanol, isopropyl alcohol, propanol, and butanol, diketones such as acetylacetone, diacetyl, and benzoylacetone, ethyl acetoacetate, and pyrubin. Ketoesters such as ethyl acetate, ethyl benzoylacetate and ethyl benzoylformate, pyrrolidones such as N-methylpyrrolidone (NMP), toluene, a mixed solvent thereof, water, and the like can be used. Can be mixed to prepare a resin mixed solution.

  The amount of the resin component contained in the electrode active material layer is desirably adjusted to such an extent that the input / output performance of the electrode plate is not deteriorated. That is, when manufacturing the electrode plate of the present invention in which the resin material is contained in the electrode active material layer, the pore diameter or porosity specified in the present invention is adjusted to an amount that can be ensured.

[Nonaqueous electrolyte secondary battery]
In general, the non-aqueous electrolyte secondary battery of the present invention includes a positive electrode plate 50 in which an electrode active material layer 54 is provided on one surface side of a current collector 55, as illustrated in FIG. An electrode plate 10 in which the electrode active material layer 2 is provided on one side of the current collector 1 to be combined (that is, the electrode plate 10 is a negative electrode plate in FIG. 2), and a polyethylene porous material between them. A separator 70 such as a film is provided. These are housed in the outer casings 81 and 82 and sealed and manufactured in a state where the outer casings 81 and 82 are filled with the non-aqueous electrolyte 90, thereby forming the non-aqueous electrolyte secondary battery 100. The

(Electrode plate)
The nonaqueous electrolyte secondary battery of the present invention is characterized in that, in particular, the electrode plate for a nonaqueous electrolyte secondary battery of the present invention described above is used as at least one of the positive electrode plate and the negative electrode plate.

  In particular, conventionally, when the negative electrode plate is composed of a carbonaceous material, it has been common to add a large amount of conductive material to the positive electrode plate in order to increase the conductivity of the positive electrode plate accordingly. For this reason, the porosity of the positive electrode plate is lowered, and the permeability of the electrolytic solution is lowered, so that it is difficult to increase the output of the battery. However, since the electrode plate of the present invention is an electrode plate capable of high input / output, when this is used as a positive electrode plate, a large amount of conductive material is not used as in the prior art, or no conductive material is used at all. Good electrical conductivity and high input / output can be achieved.

  In addition, non-aqueous electrolyte secondary batteries do not insert and remove lithium ions such as metallic lithium and its alloys, tin, silicon, and their alloys as a negative electrode active material used for the negative electrode plate, rather than carbonaceous materials such as graphite. The aspect which comprises a negative electrode plate using the material which can be separated is also included. In such a battery, a nonaqueous electrolyte secondary battery can be produced by positively using the electrode plate of the present invention as a negative electrode.

  Moreover, a nonaqueous electrolyte secondary battery can also be comprised using the electrode plate of this invention for both a positive electrode plate and a negative electrode plate.

  In the nonaqueous electrolyte secondary battery of the present invention, when the electrode plate of the present invention is used in either the positive electrode plate or the negative electrode plate, the other electrode plate is used in the nonaqueous electrolyte secondary battery. The conventionally well-known electrode plate used can be used suitably.

  As a conventionally well-known positive electrode plate, in general, at least part of the current collector surface similar to the current collector used in the electrode plate of the present invention, positive electrode active material particles, conductive material, resin binder A positive electrode active material layer-forming solution to which is added is applied, dried, and pressed as necessary.

  On the other hand, 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 a negative electrode active material layer is formed on at least a part of the current collector surface. What was formed by apply | coating a liquid, drying, and pressing as needed is used. In the negative electrode active material layer forming liquid, generally active material particles made of carbonaceous material such as natural graphite, artificial graphite, amorphous carbon, carbon black, or those obtained by adding different elements to these components, or Active material particles made of lithium ion insertion / desorption materials such as metallic lithium and alloys thereof, tin, silicon, and alloys thereof, and other additives such as resin binders and conductive materials as required It is common for agents to be mixed.

(Non-aqueous electrolyte)
The non-aqueous electrolyte 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 a lithium salt is dissolved in an organic solvent. A non-aqueous electrolyte 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 such as propylene carbonate and butylene carbonate, chain esters such as dimethyl carbonate and diethyl carbonate, cyclic ethers such as tetrahydrofuran and alkyltetrahydrofuran, and 1,2- Examples include, but are not limited to, chain ethers such as dimethoxyethane and 1,2-diethoxyethane.

  As the structure of the non-aqueous electrolyte secondary battery of the present invention produced using the positive electrode plate, the negative electrode plate, the separator, and the non-aqueous electrolyte solution, a conventionally known structure can be appropriately selected and employed. 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 may be employed in which a positive electrode plate and a negative electrode plate cut into a predetermined shape are stacked and fixed via a separator, and are accommodated in a battery container. In any structure, for example, after the positive electrode plate and the negative electrode plate are accommodated 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 being attached to the negative electrode plate. A non-aqueous electrolyte secondary battery can be manufactured by connecting the lead wire to a negative electrode terminal provided in the outer container, and further filling the battery container with a non-aqueous electrification solution and then sealing it.

  The nonaqueous electrolyte secondary battery using the electrode plate of the present invention as a positive electrode plate and / or a negative electrode plate can be used as a so-called nonaqueous electrolyte secondary battery used in a battery pack. That is, the battery pack of the present invention uses the electrode plate of the present invention as a positive electrode plate and / or a negative electrode plate, and includes a nonaqueous electrolyte secondary battery including a positive electrode terminal and a negative electrode terminal, and a protection circuit having an overdischarge protection function Are housed in a storage case. The battery pack of the present invention is equipped with a protection function for protecting the battery from, for example, overcharge, overdischarge, overcurrent, a short circuit of the battery peripheral circuit, a short circuit between the positive and negative electrodes, etc., in the nonaqueous electrolyte secondary battery itself. In addition, it may be a battery pack in which a protection circuit for preventing overcharge and overdischarge is housed and integrated in a storage case together with the non-aqueous electrolyte secondary battery. The battery pack of the present invention can be suitably used as a battery power supply device for a device that consumes a large amount of power relative to the scale of the device, such as a portable device such as a notebook computer, a camera, or a mobile phone.

  FIG. 3 shows a schematic exploded view of a battery pack 30 of the present invention using a lithium ion secondary battery 31 configured using the electrode plate of the present invention as an embodiment of the battery pack of the present invention. The battery pack 30 includes a lithium ion secondary battery 31 housed in a resin container 36a, a resin container 36b, and an end case 37. At this time, a protection circuit for preventing overcharge and overdischarge between one end face of the lithium ion secondary battery 31 and 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 inserted into an external connection window 38a provided in the resin container 36a and an external connection window 38b provided in the end case 37. Connected to an external terminal. The protection circuit board 34 includes a charge / discharge safety circuit (not shown) for controlling charge / discharge, a wiring circuit for connecting the external connection terminal and the lithium ion secondary battery 31, and the like. In addition, the battery pack 30 can employ | adopt the structure of a conventionally well-known battery pack suitably except using the lithium ion secondary battery 31 in which the electrode plate of this invention was used. Although not shown, the battery pack 30 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, an insulator, and the like between the lithium ion secondary battery 31 and the end case 37. , May be provided as appropriate.

  In addition, the non-aqueous electrolyte secondary battery of the present invention using the electrode plate of the present invention has functions such as overcurrent blocking and battery temperature monitoring in addition to the above-described protection circuit, in addition to the usage mode for battery packs. And the protection circuit may be used by being integrated with the secondary battery itself. 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 mentioned above are only illustrations, and do not limit use of the electrode plate of this invention, or the nonaqueous electrolyte secondary battery of this invention at all.

Example 1
Polyethylene oxide 1 g which is an organic substance is added to 9 g of methanol, and titanium diisopropoxybis (ethylacetoacetate) which is a metal nitride precursor (manufactured by Matsumoto Co., Ltd., TC-750) as a metal nitride precursor. 5.0 g was mixed to obtain a raw material liquid for producing metal nitride. Next, 7 g of graphite as negative electrode active material particles having an average particle diameter of 4 μm is mixed with the above raw material liquid, and the mixture is kneaded with an Excel auto homogenizer (Nihon Seiki Seisakusho Co., Ltd.) at a rotation speed of 7000 rpm for 20 minutes. A forming solution was prepared.

A copper plate having a thickness of 10 μm is prepared as a current collector, and the electrode active material layer prepared as described above is provided on one side of the current collector in an amount such that the weight of the finally obtained electrode active material layer is 15 g / m ^2. The material layer forming liquid was applied with an applicator to form an electrode active material layer forming coating film.
Next, the current collector with the electrode active material layer-forming coating film formed on the surface was placed in an electric furnace (gas replacement furnace manufactured by Koyo Thermo Systems Co., Ltd.) in a mixed gas atmosphere consisting of 10% ammonia gas and 90% nitrogen gas. ) And heated to 600 ° C. over 1 hour, and then heated for 10 minutes while maintaining the temperature at 600 ° C., and a negative electrode active material layer containing metal nitride and negative electrode active material particles on the current collector As a result, a negative electrode plate for a non-aqueous electrolyte secondary battery of the present invention in which an appropriate electrode active material layer was laminated was obtained. Then, the negative electrode plate was allowed to stand until it reached room temperature, then opened to the atmosphere, taken out, and cut into a predetermined size (a disk having a diameter of 15 mm) to obtain Example 1. In addition, it was 28 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.

Confirmation of film formation:
In preparing Example 1, the negative electrode plate for a non-aqueous electrolyte secondary battery obtained above was processed into a disk shape having a desired size. In this processing operation, an electrode active material was used. The working electrode could be formed without problems such as peeling of the layers. From this, it was confirmed that the film forming property of the electrode active material layer was good.
Also in the examples and comparative examples described below, the film forming property is good means that the electrode plate can be pulled out on the disc without any trouble as described above. On the other hand, when a part of the electrode active material layer is peeled off in the above-mentioned punching process, or the electrode active material falls from the current collector and a disc that can be used as a working electrode of a tripolar coin cell is not formed. It is assumed that the film forming property of the electrode active material layer is poor.

Adhesion evaluation:
The adhesion of the electrode active material layer to the current collector was evaluated as follows. That is, cellophane tape (“CT24” manufactured by Nichiban Co., Ltd.) was used on the surface of the obtained electrode active material layer of Example 1, and was adhered to the film with the finger pad. Subsequently, the electrode active material layer surface after peeling this off was observed and evaluated as follows. The results are shown in Table 2.
No peeling of the electrode active material layer was observed ...
Part of the surface of the electrode active material layer was coherently broken and stuck to the cello tape side, but the current collector surface was not exposed.
Part of the electrode active material layer was agglomerated and stuck to the cello tape side, and a part of the current collector surface was exposed ...・ ×

Composition analysis test:
Next, the electrode active material layer in Example 1 was shaved to obtain Sample 1. Then, composition analysis was performed by X-ray photoelectron spectroscopy (Electron Spectroscopy for Chemical Analysis) using Sample 1. As a result, Ti element was 14 atomic%, C element was 59 atomic%, O element was 12 atomic%, and N element was 15 atomic%. , Was detected. As a result, it was confirmed that titanium diisopropoxybis (ethylacetoacetate) contained in the electrode active material layer forming coating film was thermally decomposed to produce titanium nitride.

Crystallinity evaluation:
Moreover, when the crystallinity was evaluated with the X-ray-diffraction apparatus using the sample 1, it turned out that the metal nitride contained in an electrode active material layer is crystalline. For reference, the raw material liquid for producing the metal nitride is applied to a glass plate with a Miyabar No. 4 and heated under the same heating conditions as in Example 1, and the resulting laminated film is scraped off to obtain X-ray diffraction. The crystallinity was evaluated using an apparatus. It is an X-ray diffraction result of titanium nitride in the raw material liquid. Since no peak is confirmed, it was confirmed that the titanium nitride is crystalline.

Confirmation of carbon components in the binder:
The carbon component distinguished from the conductive material in the produced binder material composed of titanium nitride was confirmed by the STEM method as described below. First, Example 1 was cut substantially perpendicularly to the current collector surface, and the cross section in the thickness direction of the electrode active material layer was observed by the STEM method to observe the colored region of the carbon component by carbon element mapping. It was confirmed that particles having a diameter of about 15 nm were present in the binder. The colored region showing such a carbon component is significantly smaller than the colored region showing known graphite particles and conductive material particles, thereby confirming that a carbon component distinct from the conductive material is present in the binder. did.

Machining characteristics evaluation (bending evaluation):
The processing characteristics of Example 1 were evaluated by a cylindrical mandrel method bending test based on JIS K 5600-5-1. Example 1 is sandwiched between test plates in such a direction that the electrode active material layer surface is bent outward, both ends of the test plate are fixed, and uniformly bent at an angle of 180 degrees at a uniform speed over 2 seconds. After performing the bending test, the electrode active material layer surface of Example 1 taken out from the test plate was visually observed and evaluated as follows. In addition, this processing characteristic evaluation was implemented using the mandrel method bending test machine (made by model number REF802 SEPRO).
No film cracking on the surface of the electrode active material layer, and no peeling from the current collector ...
Some film cracking of the electrode active material layer surface or peeling from the current collector was observed, but there was no problem in use as a negative electrode plate ... ...
Could not be used as a negative electrode plate due to film cracking on the electrode active material layer surface or peeling from the current collector ...・ ・ ・ ・ ・ ・ ・ ・ ・ ×

Coating suitability evaluation:
About the applicability of the electrode active material layer forming liquid to the current collector, the surface of the coating film formed on the current collector was visually observed after the coating process, and evaluated as follows.
The surface of the coating was uniform ...
Some unevenness was confirmed on a part of the coating surface.
A streak or uneven coating was found on the coating surface ...
Clear streaks or coating unevenness that cannot be used as a negative electrode plate was confirmed on the coating surface.

<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.
Example 1 (a disk having a diameter of 15 mm, the weight of the negative electrode active material contained: 1.9 mg / 1.77 cm ² ) was used as a working electrode, a metal lithium plate as a counter electrode and a reference electrode, and the above as an electrolyte. Using this non-aqueous electrolyte, a tripolar coin cell was assembled, and this was designated as Example Test Cell 1. The example test cell 1 was subjected to the following charge / discharge test.

Charge / discharge test:
In Example Test Cell 1, which is a tripolar coin cell created as described above, first, the working electrode was subjected to a full charge according to the following charging test of Example Test Cell 1 in order to perform a discharge test of the working electrode.

(Charge test)
(Charge test)
The test cell 1 was charged at a constant current (699 μA) under an environment of 25 ° C. until the voltage reached 0.03 V. After the voltage reached 0.03 V, the voltage was 0.03 V. The current (discharge rate: 1C) was reduced until it became 5% or less so as not to fall below, and the battery was charged at a constant voltage, fully charged, and then suspended for 10 minutes. Here, the “1C” means a current value (current value reaching the discharge end voltage) at which constant current discharge is performed using the tripolar coin cell and discharge is completed in one hour. The constant current was set such that a theoretical discharge amount of 372 mAh / g of graphite as an active material was discharged in one hour at the working electrode in the example test cell 1.

(Discharge test)
Thereafter, the fully charged example test cell 1 was subjected to a constant current (699 μA) (discharge) in an environment of 25 ° C. until the voltage was changed from 0.03 V (full charge voltage) to 2.0 V (discharge end voltage). A constant current discharge at a rate of 1 C), the cell voltage (V) on the vertical axis, the discharge time (h) on the horizontal axis, a discharge curve is created, and the working electrode (electrode plate for positive electrode of Example 1) The discharge capacity (mAh) was determined and converted to the discharge capacity (mAh / g) per unit weight of the working electrode.
Subsequently, with the constant current discharge test performed at the constant current (699 μA) (discharge rate: 1 C, discharge end time: 1 hour) performed as described above as a reference, each of the constant currents was similarly applied at the discharge rates of 50 C and 100 C. A discharge test was conducted to determine the discharge capacity (mAh) of the working electrode at each discharge rate, and the discharge capacity per unit weight (mAh / g) was converted therefrom. The discharge capacity per unit weight (mAhr / g) and the discharge capacity retention rate (%) obtained by the above discharge test are shown together in Table 3.

(Calculation of discharge capacity maintenance rate (%))
In order to evaluate the discharge rate characteristics of the working electrode, each discharge capacity per unit weight (mAh / g) at each discharge rate obtained as described above was used, and the discharge capacity retention rate (%) was obtained from the above-described equation (1). Asked. The discharge capacity per unit weight (mAhr / g) and discharge capacity retention rate (%) obtained by the above discharge test were 93% at 50C and 85% at 100C.

In the present invention, the discharge rate characteristics of the electrodes are evaluated as follows.
Discharge capacity maintenance rate at discharge rate 50C 80% or more and 100% or less
Discharge capacity maintenance rate at discharge rate 50C 50% or more and less than 80%
Discharge capacity maintenance rate at 50C discharge rate Less than 50%

(Cycle characteristic evaluation test)
Following the above charge test and discharge test, a constant current charge / discharge test at a constant current (7 mA) (discharge rate: 10 C) was carried out and repeated 100 times to obtain a cycle characteristic evaluation test. The maintenance rate of the 100th discharge capacity with respect to the first discharge capacity was taken as the 100 cycle capacity maintenance rate. The cycle capacity maintenance rate is evaluated as follows. The results are shown in Table 3.

(Example 2)
An electrode active material layer forming liquid was prepared in the same manner as in Example 1 except that the material used was changed to the contents shown in Table 1. An electrode plate was prepared in the same manner as in Example 1 except that the amount applied to the current collector was changed to the amount shown in Table 2.

(Example 3)
The material used was changed to the contents shown in Table 1 to prepare an electrode active material layer forming liquid. Then, a plate having a thickness of 15 μm and a thickness of μm was prepared as a current collector, and the electrode active material layer finally obtained was applied in such an amount that the weight was 15 g / m ^2. Example 1 An electrode plate was prepared in the same manner as in Example 3.

Example 4
A positive electrode plate was prepared in the same manner as in Example 1. And Example 1 was immersed for 1 minute in the immersion tank filled with the resin liquid mixture prepared by mixing with the NMP solvent so that the density | concentration of PVDF which is a resin binder may be 1%, and the space | gap of Example 1 is carried out. The above resin mixture was sufficiently infiltrated into the resin. Then, Example 1 was taken out from the said immersion layer, and it set in the oven heated at 150 degreeC, it was made to dry for 15 minutes, and the solvent of the resin liquid mixture was removed. Thus, a positive electrode plate in which the resin binder remained in the electrode active material layer was prepared, and this was designated as Example 4.

(Reference Example 1)
An electrode plate was prepared in the same manner as in Example 1 except that the organic substance added to the electrode active material layer forming liquid was changed to polyethylene glycol 200, and this was used as Reference Example 1.

(Comparative Example 1)
Without using a metal nitride precursor, 10 g of negative electrode active material graphite having an average particle diameter of 12 μm, 1.3 g of PVDF (Kureha, KF # 1100) as a resin binder, and NMP (Mitsubishi Chemical) as a solvent The mixture is dispersed and stirred with an Excel auto homogenizer (Nihon Seiki Seisakusho Co., Ltd.) for 15 minutes at a rotational speed of 7000 rpm so that the solid concentration is 55% by weight. A forming solution was prepared.

And the said negative electrode active material layer formation liquid was apply | coated so that the coating amount of the negative electrode active material layer formation liquid after drying might be 65 g / m < ² > on the copper foil of thickness 10 micrometers used as a negative electrode collector. This was dried in an air atmosphere at 70 ° C. using an oven to form an electrode active material layer for the negative electrode plate on the current collector.
Furthermore, after pressing using a roll press machine so that the thickness of the formed electrode active material layer is about 85 μm, it is cut into a predetermined size (a disk having a diameter of 15 mm) and 300 ° C. at 70 ° C. A negative electrode plate was produced by vacuum-drying for minutes to obtain Comparative Example 1.

(Comparative Examples 2 to 5)
The particle diameter of the active material particles to be used was changed as shown in Table 1, and the coating amount of the electrode active material layer forming liquid on the current collector and the thickness of the electrode active material layer were changed as shown in Table 2. Except for this, an electrode plate was produced in the same manner as in Comparative Example 1 to obtain Comparative Examples 2 to 5.

Composition analysis test:
Next, as in Example 1, the composition analysis of Examples 2 and 3 was performed by X-ray photoelectron spectroscopy (Chemical Analysis for Chemical Analysis). Nickel titanium nitride was nitrided in Example 2, and nitrided in Example 3. It was confirmed that aluminum was produced.

  For Examples 2 to 4 and Reference Example 1 obtained as described above, film formation evaluation, adhesion evaluation, (composition analysis), confirmation of the crystallinity of the binder, and confirmation of the carbon component in accordance with Example 1. The coating aptitude and processing aptitude test were conducted. The results are shown in Table 2. Moreover, about Comparative Examples 1-5, the film formation evaluation, coating suitability, and workability test were done according to Example 1. The results are shown in Table 2.

In addition, with respect to Examples 2 to 4, Reference Example 1, and Comparative Example 1, a charge / discharge test and a cycle characteristic evaluation test were performed according to Example 1. The results of the charge / discharge test are summarized in Table 3. In the charge / discharge test, as in the above-described example test cell 1, the example test cells 2 to 4 and the reference example test cell 1 were prepared, and the specific constant current values and full charge voltage values shown in Table 3 were discharged. A charge / discharge test was performed in the same manner as described above except that the voltage was changed to the end voltage value. In Comparative Examples 2 to 5, the film-forming property was poor and could not be used for the charge / discharge test.

  From the above results, Examples 1 to 5 showed good film-forming properties, good adhesion of the electrode active material layer, and good input / output characteristics. Moreover, when Examples 1-5 were compared with the reference example 1, all the input / output characteristics were favorable, but in the evaluation of the processing characteristics, Examples 1-5 showed excellent evaluations. It was. As a result, it was confirmed that advantageous effects were exhibited by the carbon component contained in the binder.

1, 1 ′, 1 ″, 55 Current collector 2, 54 Electrode active material layer 3, Current collecting base material 4 Conductive layer 5 Intermittent layer 10, 20, 20 ′, 20 ″, 20 ′ ″ Non-aqueous Electrode plate for electrolyte secondary battery 30 Battery pack 31 Lithium ion secondary battery 32 Positive electrode terminal 33 Negative electrode terminal 34 Protective circuit board 35 External connection connector 36a, 36b Resin container 37 End case 38a, 38b External connection window 50 Non-water Electrode plate for secondary battery (positive electrode plate)
70 Separator 81, 82 Exterior 90 Non-aqueous electrolyte 100 Lithium ion secondary battery

Claims (10)

An electrode plate for a nonaqueous 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 active material particles and a binder,
An electrode plate for a non-aqueous electrolyte secondary battery, wherein the binder material contains a crystalline metal nitride and a carbon component. The electrode plate for a non-aqueous electrolyte secondary battery according to claim 1, wherein the metal nitride contains at least Ti element. The electrode active material layer is configured such that active material particles are fixed to each other by a binding material, and the active material particles are fixed to a current collector by a binding material. The electrode plate for nonaqueous electrolyte secondary batteries according to 1 or 2. 4. The non-electrode according to claim 1, wherein the electrode active material layer includes a portion in which a part of adjacent binder materials are connected by a continuous crystal lattice. 5. Electrode plate for water electrolyte secondary battery. 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 an electrolyte containing a non-aqueous solvent,
The said positive electrode plate and / or negative electrode plate are the electrode plates for nonaqueous electrolyte secondary batteries of any one of Claims 1 thru | or 4, The nonaqueous electrolyte secondary battery characterized by the above-mentioned. An electrode active material layer forming liquid containing at least active material particles, a metal nitride generating material for generating metal nitride, and an organic material is applied to at least a part of the current collector to form a coating film. A coating process to be formed and an electrode active material layer forming process are provided in this order,
The electrode active material layer forming step includes reacting the metal nitride generating material to generate crystalline metal nitride, forming a binding material containing the metal nitride, and forming the organic material-derived carbon component In the binder material, thereby forming an electrode active material layer containing the binder material and the active material particles on the current collector. A method for producing an electrode plate for a secondary battery. An electrode active material layer forming liquid containing at least active material particles and a metal nitride generating organic material for generating metal nitride is applied to at least a part of the current collector to form a coating film. A coating process to be formed and an electrode active material layer forming process are provided in this order,
The electrode active material layer forming step includes reacting the metal nitride generating material to generate crystalline metal nitride, forming a binder containing the metal nitride, and forming the metal nitride. It is a step of forming an electrode active material layer containing a binding material and the active material particles on the current collector by leaving a carbon component derived from an organic material in the binding material. A method for producing an electrode plate for a non-aqueous electrolyte secondary battery. An electrode active material layer forming liquid containing at least active material particles, a metal nitride generating organic material for generating metal nitride, and an organic material is applied to at least a part of the current collector. A coating process for forming a coating film and an electrode active material layer forming process are provided in this order,
The electrode active material layer forming step includes reacting the organic material for generating metal nitride to generate crystalline metal nitride, forming a binder containing the metal nitride, and forming the metal nitride. In the step of forming an electrode active material layer containing the binding material and the active material particles on the current collector by leaving the organic material for generation or the carbon component derived from the organic substance in the binding material. A method for producing an electrode plate for a non-aqueous electrolyte secondary battery. The electrode active material layer forming step is a heating step for heating the coating film,
The heating temperature in the heating step is equal to or higher than the thermal decomposition start temperature of the metal nitride generating material or the metal nitride generating organic material, and is equal to or higher than the crystallization temperature of the metal nitride generated in the heating step, The nonaqueous electrolysis according to any one of claims 6 to 8, wherein the temperature is set to a temperature at which a carbon component in at least one of the organic material for forming a metal nitride or the organic material remains in the binder. Manufacturing method of electrode plate for liquid secondary battery. 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 non-aqueous electrolyte secondary battery includes at least a positive electrode plate, a negative electrode plate, a separator provided between the positive electrode plate and the negative electrode plate, and an electrolyte solution containing a non-aqueous solvent. A secondary battery,
Either one of the said positive electrode plate or a negative electrode plate, or both is the electrode plate for nonaqueous electrolyte secondary batteries of any one of Claims 1 thru | or 4. The battery pack characterized by the above-mentioned.

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