JP3785407B2 - Electrode composite particle manufacturing method, electrode manufacturing method and electrochemical element manufacturing method, and electrode composite particle manufacturing apparatus, electrode manufacturing apparatus and electrochemical element manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of composite particles for an electrode which can fully reduce irreversible capacitance. <P>SOLUTION: The production method of the composite particles for the electrode includes a plasma treatment process for obtaining particles made of electrode active materials having electron conductivity by applying high frequency thermal plasma treatment to a raw material made of a carbonaceous material; and a granulation process for forming the composite particles for the electrode including an electrode active material, a conductive assistant, and a binder by integrating particles made of the electrode active materials obtained after the plasma treatment, the conductive assistant, and the binder which can bind the electrode active materials and the conductive assistant while sticking them to each other. The granulation process is performed in an inert gas atmosphere. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention is for an electrode that is a constituent material of an electrode that can be used for an electrochemical element such as a primary battery, a secondary battery (especially a lithium ion secondary battery), an electrolytic cell, and a capacitor (especially an electrochemical capacitor). The present invention relates to a method for producing composite particles, a method for producing electrodes formed using the composite particles for electrodes obtained thereby, and a method for producing an electrochemical device provided with the electrodes. Moreover, this invention relates to the composite particle manufacturing apparatus for electrodes provided with the mechanism based on said each manufacturing method, an electrode manufacturing apparatus, and an electrochemical element manufacturing apparatus.

  The development of portable devices in recent years is remarkable, and the major driving force is the development of high energy batteries such as lithium ion secondary batteries widely used as the power source of these devices. The high energy battery is mainly composed of a cathode, an anode, and an electrolyte layer (for example, a layer made of a liquid electrolyte or a solid electrolyte) disposed between the cathode and the anode.

  Electrochemical elements such as high energy batteries such as lithium ion secondary batteries and electrochemical capacitors such as electric double layer capacitors are the future of devices such as portable devices where electrochemical elements should be installed. Various research and development are being carried out with the aim of further improving the characteristics in order to respond to the development of this.

  In order to improve the performance of the lithium ion secondary battery, the selection of the electrode material is important. The carbon material which is a constituent material of the anode is rich in variety, and various carbon materials have been studied from highly crystalline graphite to carbonized polymer.

  Electrochemical characteristics such as charge / discharge potential, reversible capacity, and cycle characteristics of the battery include crystallinity (graphitization degree), surface morphology, internal structure, surface chemical composition, etc. of the carbon material used as the anode active material (negative electrode active material). Strongly depends on. In addition, in a lithium ion secondary battery using a carbon material as the anode active material, the effect on the characteristics due to SEI (Solid Electrolyte Interface) formed on the surface of the anode active material during the first charge is large. SEI is generated by the reaction between the anode active material and the electrolytic solution, and once SEI is formed, further reaction is suppressed, so that lithium can be inserted between the graphite layers. However, SEI is one of the causes of irreversible capacity. In addition, the thermal stability related to the safety of the battery depends on the stability of SEI. Since SEI is formed by the reaction between the anode active material and the electrolyte, the surface of the carbon material such as the amount of oxygen-containing functional groups such as carboxy groups and carbonyl groups on the carbon particle surface, and the surface crystallinity of the carbon particles. Largely affected by structure.

  And, to solve such problems, to obtain good electrode characteristics and battery characteristics, particularly to reduce the irreversible capacity, a carbon material that becomes an electrode active material (after activated treatment, activated carbon, etc. ) Is subjected to thermal plasma treatment to clean the surface of the carbon material (see, for example, Patent Document 1 and Patent Document 2 below).

  Although the detailed mechanism has not been elucidated, in general, electrochemical characteristics such as reversible capacity, withstand voltage characteristics, cycle characteristics, and stability at high temperature storage of an electrochemical capacitor are the same as those of particles made of a carbon material as an electrode active material. It is known that the crystallinity (graphitization degree), surface morphology, internal structure, surface chemical composition, adsorbed water amount, etc. are greatly affected. It is also known that the amount of oxygen-containing functional groups such as carboxy groups and carbonyl groups on the surface of the carbon material particles has a great influence on the electrochemical characteristics.

  The above technology cleans the surface of the carbon material that becomes the electrode active material by thermal plasma treatment, and makes the physical and chemical state of the surface suitable for obtaining sufficient electrochemical characteristics. It is intended.

Also, a slurry comprising a positive electrode active material (cathode active material), a conductive agent (conductive auxiliary agent), a binder and a solvent and having a solid content of 20 to 50% by weight and an average particle size of 10 μm or less is prepared. In addition, a method for producing a positive electrode mixture for an organic electrolyte battery intended to further improve characteristics such as discharge characteristics and productivity by granulating the slurry by spray drying (spray drying) has been proposed ( For example, see Patent Document 3).
JP-A-10-92432 JP 2000-223121 A JP 2000-40504 A

  However, even with an electrode including a carbon material subjected to thermal plasma treatment as a constituent material and a battery using the same as disclosed in Patent Documents 1 and 2 described above, sufficient electrode characteristics and battery characteristics are still present. Was not obtained, and there was room for further improvement.

  Further, even in the lithium secondary battery using the positive electrode for a lithium secondary battery described in Patent Document 3 described above, sufficient electrode characteristics and battery characteristics have not yet been obtained, and there is room for further improvement. Had.

  Also, other types of primary batteries and secondary batteries of the above-described lithium ion secondary battery have the same problems as described above.

  Furthermore, instead of the electrode active material in the battery, an electroconductive cell having an electrode in which an electron conductive material (carbon material or metal oxide) is used as the electrode active material, and at least a conductive additive and a binder, Also, capacitors (for example, electrochemical capacitors including electric double layer capacitors) have the same problems as described above.

  This invention is made | formed in view of the subject which the said prior art has, and aims at providing the manufacturing method of the composite particle for electrodes which can fully reduce an irreversible capacity | capacitance. Moreover, an object of this invention is to provide the manufacturing method of the electrode which can fully reduce an irreversible capacity | capacitance. Furthermore, an object of the present invention is to provide a method for producing an electrochemical device in which the irreversible capacity is sufficiently reduced and sufficient reversible capacity and charge / discharge efficiency (particularly, initial charge / discharge efficiency) can be obtained.

  Another object of the present invention is to provide an electrode composite particle manufacturing apparatus that can easily and reliably manufacture electrode composite particles capable of sufficiently reducing the irreversible capacity. Furthermore, an object of the present invention is to provide an electrode manufacturing apparatus capable of easily and reliably manufacturing an electrode capable of sufficiently reducing the irreversible capacity. Furthermore, the present invention provides an electrochemical element manufacturing that can easily and reliably manufacture an electrochemical element that has a sufficiently reduced irreversible capacity and can obtain a sufficient reversible capacity and charge / discharge efficiency (especially initial charge / discharge efficiency). An object is to provide an apparatus.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have sufficient electrodes and electrochemical elements manufactured by a technique for manufacturing an electrode using thermal plasma treatment and an electrochemical element equipped with the electrode. Electrochemical properties are not obtained because the surface-cleaned carbon material is exposed to an atmosphere containing moisture and oxygen, such as in the atmosphere, in the process of manufacturing the electrode after plasma treatment and manufacturing the electrochemical element. It has been found that this is one of the major causes.

  That is, in the prior art using thermal plasma treatment, the carbon material whose surface has been cleaned is exposed to an atmosphere containing moisture and oxygen, such as the atmosphere, after the thermal plasma treatment. Therefore, moisture adheres again to the cleaned surface of the carbon material after the plasma treatment, or the reaction with oxygen proceeds on the surface and the oxygen-containing functional groups described above are bonded to the surface. The present inventors have found that the electrochemical characteristics due to the plasma treatment are not sufficiently improved due to the influence.

  For example, when water is attached to the carbon material in the electrode, when water is applied to the electrochemical element, the water is easily decomposed, causing irreversible capacity to be generated, and cycle characteristics are deteriorated. Furthermore, in the electrode, there is a gas generated by the decomposition of water, or water exists as water vapor, so that a sufficient electric double layer cannot be formed and the capacity is reduced. Furthermore, if moisture (liquid or solid) is attached, the impedance of the electrode increases and the cycle characteristics deteriorate. Moreover, since the decomposition reaction of the non-aqueous electrolyte solution at a high temperature (45 ° C. or higher) is promoted by a very small amount of water in the electrode, the stability during storage at a high temperature (45 ° C. or higher) is particularly lowered. Furthermore, when an oxygen-containing functional group is present, a sufficient electric double layer cannot be formed and the capacity is lowered.

  For example, the inventors of a carbon material that has been subjected to high-frequency thermal plasma treatment that has been left in the atmosphere (temperature: 25 ° C., relative humidity: 45%) for 2 hours has a temperature-programmed desorption mass spectrometer ( As a result of measurement by TDS), it was confirmed that a large amount of gas derived from a hydroxyl group was generated from the surface of the carbon material.

  As a result of further investigations, the present inventors have found that it is extremely effective for accomplishing the above-mentioned purpose to perform all steps of electrode production after plasma treatment and electrochemical device production in an inert gas atmosphere. I found out.

  As a result of intensive studies to achieve the above object, the present inventors have found that in the conventional electrode forming method, at least the electrode active material, the conductive auxiliary agent, and the binder described above are applied at the time of electrode formation. Since a method using a liquid (slurry) or a kneaded product is employed, a conductive network in which the electrode active material, conductive additive and binder are dispersed in the active material-containing layer of the resulting electrode can be constructed. It has been found that a state in which the dispersion is not performed, for example, the dispersion state is not uniform, has a great influence on the occurrence of the above-described problem.

  The present inventors also provide composite particles containing at least an electrode active material, a conductive assistant and a binder as constituent materials, wherein the electrode active material, the conductive assistant and the binder are sufficiently dispersed. The inventors have found that adopting particles as an electrode is extremely effective in achieving the above object, and have reached the present invention.

That is, the present invention provides a plasma treatment step of obtaining particles made of an electrode active material having electron conductivity by subjecting a raw material made of a carbonaceous material to a high-frequency thermal plasma treatment in a plasma gas atmosphere,
By adhering and integrating the conductive assistant and the binder capable of binding the electrode active material and the conductive assistant to the particles made of the electrode active material obtained after the plasma treatment step, A granulation step of forming composite particles for an electrode comprising an electrode active material, a conductive additive, and a binder;
Have
Performing the granulation process in an inert gas atmosphere;
The manufacturing method of the composite particle for electrodes characterized by these is provided.

  Here, in the present invention, “inert gas” refers to a rare gas and a nitrogen gas. The “inert gas atmosphere” means that the ratio of the inert gas is 99.9% or more, preferably 99.9% or more, and the relative humidity is 0.5% (dew point temperature is about −40 ° C.). Hereinafter, the atmosphere is preferably 0.04% or less (dew point temperature of about −60 ° C.) or less, and the oxygen ratio is 10 ppm or less, preferably 1 ppm or less. Furthermore, the “inert gas atmosphere” in the granulation step can be realized by performing the manufacturing step after the granulation step using “inert gas atmosphere forming means” such as a dry room or a glove box.

  As described above, according to the method for producing composite particles for an electrode of the present invention, the carbon material which is an electrode active material obtained by plasma treatment is obtained by performing the production process after the granulation process in an inert gas atmosphere. The surface can be cleaned and the physical and chemical state of the surface can be maintained in a state suitable for obtaining sufficient electrochemical properties.

  Since the carbon material for an electrode of the present invention is subjected to such a high-frequency thermal plasma treatment, the vicinity of the material surface has a turbulent structure, and a small amount of oxygen or hydrogen present on the material surface is present. Is removed to modify the surface. In particular, in the present invention, since the plasma treatment is performed in a plasma gas atmosphere, the SEI generation reaction can be improved and the stability of SEI can be improved. And the irreversible capacity | capacitance produced at the time of SEI production | generation can fully be reduced.

  Therefore, from the above viewpoint, an electrode and an electrochemical element capable of obtaining sufficient electrochemical characteristics can be obtained by using the composite particles for an electrode formed using this carbon material as a constituent material. In particular, the reversible capacity and charge / discharge efficiency (initial charge / discharge efficiency) of the electrode and the electrochemical device can be improved.

Here, “high-frequency thermal plasma” is plasma generated from medium pressure (about 10 to 70 kPa) to 1 atm. Unlike normal low-pressure plasma, plasma close to thermal equilibrium can be obtained. Not only can the reaction be carried out, but also the materials present in the system can be raised to high temperatures. Therefore, both the generation of the high temperature phase and the surface modification are enabled by the high frequency thermal plasma. Specific phenomena include, for example, surface nitrogenation when N ₂ is used as the plasma gas, surface hydrogenation when H ₂ is used, physical destruction at the atomic level, or cleaning of the particle surface. Can be considered.

  When high-frequency thermal plasma is used for surface treatment of particles made of carbonaceous material, “raw material” of particles made of carbonaceous material (particles made of carbonaceous material) is graphitized by ultra-high temperature treatment using high-frequency thermal plasma atmosphere, Furthermore, the surface is modified by hitting with ions, radicals and the like. Here, the “carbonaceous material” refers to a material that becomes a carbon material having electron conductivity by performing the above-described high-frequency thermal plasma treatment. The carbonaceous material itself does not necessarily have electron conductivity. The carbonaceous material in this case includes a resin material containing carbon as a constituent element in addition to the carbon material. For example, graphite, pitch material, coconut shell, phenol resin, etc. are mentioned.

  And in the manufacturing method of the composite particle for an electrode of the present invention using the plasma treatment process, the carbon material that is the constituent material of the electrode obtained by the plasma treatment process is subjected to such a high-frequency thermal plasma treatment, The surface of the material has a turbulent structure, and a small amount of oxygen or hydrogen present on the surface of the material reacts with the surface to introduce new functional groups. Therefore, it is considered that a suitable surface condition is realized.

  The composite particles obtained by the method for producing composite particles for electrodes according to the present invention are particles in which each of the conductive assistant, the electrode active material, and the binder is brought into close contact with each other in a very good dispersion state. And this composite particle is used as a main component of the powder at the time of manufacturing the active material content layer of an electrode by the dry method mentioned later, or manufactures the active material content layer of an electrode by the wet method mentioned later It is used as a constituent material of the coating liquid or kneaded product.

  A very good electron conduction path (electron conduction network) is three-dimensionally constructed inside the composite particle. The structure of this electron conduction path is substantially the same even after the active material-containing layer is formed by heat treatment when the active material-containing layer of the electrode is used as the main component of the powder when it is produced by the dry method described later. This state can be maintained. In addition, the structure of this electron conduction path is such that when the active material-containing layer of the electrode is used as a constituent material of a coating solution or kneaded product when the wet method described later is used, the coating solution or kneaded product containing the composite particles is used. Even after the preparation, the initial state can be easily maintained by adjusting the preparation conditions (for example, selection of a dispersion medium or a solvent when preparing the coating liquid).

  Therefore, from the above viewpoint, by using the composite particles obtained by the method for producing composite particles for electrodes of the present invention as a constituent material, it is possible to obtain an electrode and an electrochemical element that can obtain sufficient electrochemical characteristics. it can.

  On the other hand, the conventional electrode forming method employs the method using the coating liquid or kneaded material containing at least the electrode active material, the conductive auxiliary agent, and the binder described above at the time of electrode formation. The electrode active material, the conductive additive and the binder in the active material-containing layer are not uniformly dispersed, and this has a great influence on the occurrence of the above-mentioned problems. The inventors have found.

  Here, in the present invention, the “electrode active material” that is a constituent material of the composite particles refers to the following substances depending on the electrode to be formed. That is, when the electrode to be formed is an electrode used as an anode of a primary battery, the “electrode active material” indicates a reducing agent, and when the electrode is a cathode of a primary battery, the “electrode active material” is an oxidation. Indicates an agent. Further, the “particles made of an electrode active material” may contain substances other than the electrode active material to the extent that the function of the present invention (the function of the electrode active material) is not impaired.

  In addition, when the electrode to be formed is an anode (during discharge) used for a secondary battery, the “electrode active material” is a reducing agent and can be used in any state of the reduced form and the oxidized form. It is a substance that can exist stably in a stable manner, and a substance capable of reversibly proceeding from a reduction reaction from an oxidant to a reductant and from a reductant to an oxidant. Furthermore, when the electrode to be formed is a cathode (during discharge) used in a secondary battery, the “electrode active material” is an oxidant, and it can be used in any state of its reduced form and oxidant. It is a substance that can exist stably in a stable manner, and a substance capable of reversibly proceeding from a reduction reaction from an oxidant to a reductant and from a reductant to an oxidant.

  In addition to the above, when the electrode to be formed is an electrode used for a primary battery and a secondary battery, the “electrode active material” stores or releases metal ions involved in the electrode reaction (intercalation, Alternatively, a material that can be doped / undoped) may be used. Examples of this material include carbon materials used for anodes and / or cathodes of lithium ion secondary batteries, metal oxides (including composite metal oxides), and the like.

  For the convenience of explanation, the anode electrode active material is referred to as “anode active material” and the cathode electrode active material is referred to as “cathode active material” in this specification. In this case, the “anode” in the case of the “anode active material” is based on the polarity when the battery is discharged (negative electrode active material), and the “cathode” in the case of the “cathode active material” is the battery. Based on the polarity at the time of discharge (positive electrode active material). Specific examples of the anode active material and the cathode active material will be described later.

  Further, in the case where the electrode to be formed is an electrode used for an electrolytic cell or an electrode used for a capacitor (capacitor), the “electrode active material” refers to a metal (including a metal alloy) having electronic conductivity. ), A metal oxide or a carbon material.

  In the present invention, the granulation step may be characterized in that the granulation step is performed based on a spray drying method. As a result, it is possible to obtain an electrode with uniform density and the like while reducing the irreversible capacity.

In the present invention, the granulation step is
A raw material liquid preparation step of preparing a raw material liquid containing a binder, a conductive additive and a solvent;
A fluidized bed forming step of charging particles made of an electrode active material into a fluidized tank and fluidizing the particles made of the electrode active material;
By spraying the raw material liquid into the fluidized bed containing the particles made of the electrode active material, the raw material liquid is attached to the particles made of the electrode active material and dried, and the solvent from the raw material liquid attached to the surface of the particles made of the electrode active material A spray-drying step in which the particles made of the electrode active material and the particles made of the conductive auxiliary agent are brought into close contact with the binder,
It is preferable that it contains.

  In addition, the present inventors generally form the electrode composite particles through the above-described granulation step, so that generally when the electrode (or composite particles that constitute the constituent material) is formed using a binder, In spite of the general recognition of those skilled in the art that the internal resistance of the electrode (or the composite particles constituting the electrode) tends to increase, the following has been found.

  That is, the present inventors previously formed composite particles containing an electrode active material, a conductive additive and a binder through the above granulation step, and if this is used as an electrode, the binder is included. Nevertheless, it has been found that an electrode (composite particle) having a specific resistance value (or an internal resistance value when normalized with an apparent volume) sufficiently lower than the value of the electrode active material itself can be constructed.

  By adopting the granulation process having the above-described configuration, it is possible to more reliably form composite particles in which the above-described extremely good electron conduction path (electron conduction network) is three-dimensionally constructed. .

  And the electrode formed using the composite particle for electrodes obtained through the granulation step is formed in a state where the structure of the composite particle is maintained, and in the active material-containing layer, “electrode active material and conductive additive” Are electrically connected without being isolated ”. Therefore, a very good electron conduction path (electron conduction network) is three-dimensionally constructed in the active material containing layer.

  Here, “in the composite particles, the electrode active material and the conductive additive are electrically coupled without being isolated” means that the particles (or their aggregates) made of the electrode active material in the active material-containing layer. (Aggregate) and particles (or aggregates thereof) made of a conductive additive are electrically connected without being “substantially” isolated. More specifically, the particles made of the electrode active material (or aggregates thereof) and the particles made of the conductive additive are not completely isolated without being electrically isolated, but at a level where the effects of the present invention can be obtained. It shows that it is electrically coupled within a range where electric resistance can be achieved.

  And, in this “composite particle, the electrode active material and the conductive additive are electrically coupled without being isolated” is the SEM (Scanning Electron Micro Scope) of the cross section in the composite particle of the electrode of the present invention. : Scanning electron microscope), TEM (Transmission Electron Microscope), and EDX (Energy Dispersive X-ray Fluorescence Spectrometer) analysis data. The electrode of the present invention is obtained by comparing the SEM photograph, TEM photograph and EDX analysis data of the cross section in the composite particle with the SEM photograph, TEM photograph and EDX analysis data of the conventional electrode (or composite particle). And can be clearly distinguished from conventional electrodes (or composite particles).

  More specifically, in the granulation step described above, in the fluidized tank, the fine particles of the raw material liquid containing the conductive auxiliary agent and the binder are directly sprayed onto the particles made of the electrode active material. It is possible to sufficiently prevent the constituent particles constituting the agglomeration from proceeding, and as a result, it is possible to sufficiently prevent the uneven distribution of the constituent particles in the obtained composite particles. In addition, the conductive auxiliary agent and the binder can be selectively dispersed well on the surface of the electrode active material that can be brought into contact with the electrolytic solution and participate in the electrode reaction.

  Therefore, the composite particles are particles in which the conductive auxiliary agent, the electrode active material, and the binder are adhered to each other in a very good dispersion state. Further, the composite particles of the present invention, in the granulation step, the temperature in the fluidized tank, the spray amount of the raw material liquid sprayed in the fluidized tank, and the electrode charged in the fluid flow (for example, the airflow) generated in the fluidized tank Adjust the particle size and shape arbitrarily by adjusting the amount of active material input, fluidized bed velocity, fluidized bed (fluid flow) flow (circulation) mode (laminar flow, turbulent flow, etc.), etc. Can do.

  As described above, in the above granulation step, it is only necessary to directly spray droplets of the raw material liquid containing the conductive auxiliary agent on the flowing particles, and the flow method is not particularly limited. For example, an air flow is generated. A fluid tank in which particles are caused to flow by the air flow, a fluid tank in which particles are rotationally fluidized by a stirring blade, a fluid tank in which particles are fluidized by vibration, and the like can be used. However, in the method for producing composite particles for electrodes, in order to improve the drying efficiency and make the shape and size of the obtained composite particles uniform, an air stream is generated in the fluidized tank in the fluidized bed process. It is preferable that particles made of the electrode active material are introduced into the air flow to make the particles made of the electrode active material fluidized.

  A very good electron conduction path (electron conduction network) is three-dimensionally constructed inside the composite particle. As a result, the inventors of the present invention have a three-dimensionally excellent electron conduction path (electron conduction network) in the electrode (composite particle) used in the electrochemical device of the present invention as compared with the conventional electrode. I guess it is built.

  Here, in the method for forming a plate-like electrode used in a conventional film-like electrochemical element, the present inventors used the electrode active material, the conductive additive, and the binder described above at the time of electrode formation. Since a method using at least a coating liquid (slurry) or a kneaded material is adopted, the conductive network in which the active state of the electrode active material, the conductive assistant and the binder in the active material-containing layer of the obtained electrode is effective It has been found that a state in which the above-mentioned problem has not been established, for example, that the dispersion state is not uniform, has a great influence on the occurrence of the above-described problem.

  That is, in the conventional method using a coating solution or kneaded product, the coating solution or kneaded product is applied to the surface of the current collecting member to form a coating film made of the coating solution or kneaded product on the surface, and this coating film is dried. The active material-containing layer is formed by removing the solvent. In the process of drying the coating film, the present inventors lifted the conductive assistant and binder having a low specific gravity to the vicinity of the coating film surface, and as a result, the electrode active material, conductive assistant and A state in which the dispersed state of the binder cannot form an effective conductive network, for example, this dispersed state becomes non-uniform, and the adhesion between the three of the electrode active material, the conductive auxiliary agent, and the binder is sufficient. It was not obtained, and it was found that a good electron conduction path was not established in the obtained active material-containing layer.

  Furthermore, a method of granulating a coating liquid (slurry) by spray drying, that is, an electrode active material, a conductive agent and a binder by spray drying a slurry comprising a solvent in hot air. A method for producing a lump (composite particle) made of is conventionally known. In this case, since the electrode active material, the conductive auxiliary agent, and the binder are included in the same slurry, the electrode active material, the conductive auxiliary agent, and the binder in the resulting granulated product (composite particles). The dispersion state of the adhesive is the dispersion state of the electrode active material, the conductive assistant, and the binder in the slurry (particularly, the electrode active material, the conductive assistant, and the binder in the process of drying the slurry droplets). Depending on the dispersion state of the binder), the aggregation of the binder and its uneven distribution, and the aggregation and the uneven distribution of the conductive assistant occur, and the electrode active material, conductive assistant and A state in which the dispersed state of the binder cannot form an effective conductive network, for example, this dispersed state becomes non-uniform, and the adhesion between the three of the electrode active material, the conductive auxiliary agent, and the binder is sufficient. No good electron conduction path is established in the active material-containing layer obtained. I found the door.

  Further, in this case, the inventors cannot contact the conductive auxiliary agent and the binder with the electrolytic solution and selectively and well disperse the conductive auxiliary agent and the binder on the surface of the electrode active material that can participate in the electrode reaction. There is a wasteful conductive aid that does not contribute to the construction of an electron conduction network that efficiently conducts electrons generated in the field, or a wasteful binder that simply increases electrical resistance. I found out.

  In the case of a method for producing a lump (composite particle) composed of an electrode active material, a conductive agent and a binder by spray drying a slurry comprising a solvent in hot air, the electrode active material, the conductive agent and the binder Since the drying and solidification proceed in a state where the agent is dispersed in the solvent, the aggregation of the binder and the aggregation of the conductive agent proceed during the drying, and each electrode active material constituting the obtained mass (composite particle) The present inventors have found that the conductive agent and the binder are not in close contact with the surface of the resulting particles while maintaining an effective conductive network and sufficiently dispersed.

  More specifically, as shown in FIG. 25, the particles made of each positive electrode active material constituting the obtained lump (composite particle) P100 are surrounded only by aggregates P33 made of a large binder, The present inventors have found that there are many P11 that are not electrically isolated and used in the lump (composite particle) P100. Further, when the particles made of the conductive agent become an aggregate during drying, the particles made of the conductive agent are unevenly distributed as the aggregate P22 in the obtained lump (composite particle) P100, and the lump (composite particle) P100 The present inventors have found that a sufficient electron conduction path (electron conduction network) cannot be constructed and sufficient electron conductivity cannot be obtained. Further, the aggregate P22 of particles made of a conductive agent may be electrically isolated by being surrounded only by the aggregate P33 made of a large binder, and from this point of view, sufficient electrons in the lump (composite particle) P100 The present inventors have found that a conduction path (electron conduction network) cannot be constructed and sufficient electron conductivity cannot be obtained.

  Here, in the granulation step of the present invention, the above-mentioned “integrating the conductive auxiliary agent and the binder in close contact with the particles made of the electrode active material” means the surface of the particles made of the electrode active material. It indicates that at least a part of the particles made of the conductive auxiliary agent and the particles made of the binder are brought into contact with each other. That is, it is sufficient that the surfaces of the particles made of the electrode active material are partially covered with the particles made of the conductive auxiliary agent and the particles made of the binder, and the whole need not be covered. In addition, the “binder” used in the granulation step of the method for producing composite particles of the present invention indicates a binder capable of binding the electrode active material used together with the conductive aid.

  In the present invention, a very good ion conduction path can be easily formed in the composite particles (ie, electrodes) by further adding a conductive polymer having ion conductivity as a constituent material when forming the composite particles. Can be built.

  Further, when a conductive polymer having ionic conductivity can be used as a binder as a constituent material of the composite particles, a conductive polymer having ionic conductivity may be used. It is considered that the binder having ion conductivity also contributes to the construction of an ion conduction path in the electrode (composite particle). By using this composite particle, a polymer electrode composed of the composite particle can be formed. Moreover, you may use the polymer electrolyte which has electronic conductivity as a binder used as the constituent material of composite particle.

  By setting it as such a structure, in this invention, the electrode which has the electronic conductivity and ionic conductivity superior to the conventional electrode can be formed easily and reliably. An electrode composed of composite particles has a three-dimensional and sufficiently large contact interface with a conductive assistant, an electrode active material, and an electrolyte (solid electrolyte or liquid electrolyte) that serve as a reaction field for a charge transfer reaction that proceeds inside the composite particle. Is formed.

  Further, in the present invention, since composite particles having extremely good dispersion states of the conductive auxiliary agent, the electrode active material, and the binder are formed in advance, the addition amount of the conductive auxiliary agent and the binder is more sufficient than before. Can be reduced.

  In the present invention, when a conductive polymer is used, the conductive polymer may be the same as or different from the conductive polymer that is a constituent element of the composite particles described above.

  In the present invention, from the viewpoint of more easily and more reliably forming the composite particles having the structure described above, the granulation step is performed at a temperature in the fluidized tank of 50 ° C. or higher and the melting point of the binder. It is preferable to adjust the temperature so as not to greatly exceed, and it is more preferable to adjust the temperature in the fluidized tank to 50 ° C. or higher and below the melting point of the binder. The melting point of the binder is, for example, about 200 ° C. although it depends on the type of the binder. When the temperature in the fluidized tank is less than 50 ° C., the tendency of drying of the solvent during spraying becomes large. When the temperature in the fluidized tank greatly exceeds the melting point of the binder, the tendency of the binder to melt and greatly hinder the formation of particles increases. If the temperature in the fluidized tank is a temperature that is slightly higher than the melting point of the binder, the above problem can be sufficiently prevented depending on the conditions. Moreover, if the temperature in a fluid tank is below melting | fusing point of a binder, said problem will not generate | occur | produce.

  Furthermore, in the present invention, from the viewpoint of more easily and more reliably forming composite particles having the structure described above, the air flow generated in the fluidized tank in the granulation step may be the same as the atmosphere. In order to exhibit the effect of the invention more, it is preferable that the air flow is made of an inert gas. Furthermore, in the granulation step, the humidity (relative humidity) in the fluidized tank is preferably set to a dew point of −40 ° C. or lower in the above preferable temperature range. The “inert gas” indicates a gas belonging to a rare gas and a nitrogen gas as described above.

  In the present invention, in the granulation step, it is preferable that the solvent contained in the raw material liquid can dissolve or disperse the binder and disperse the conductive assistant. Also by this, the dispersibility of the binder, conductive additive and electrode active material in the composite particles obtained can be further enhanced. From the viewpoint of further improving the dispersibility of the binder, the conductive auxiliary agent and the electrode active material in the composite particles, the solvent contained in the raw material liquid can dissolve the binder and can disperse the conductive auxiliary agent. More preferred.

  Further, in the present invention, from the viewpoint of more reliably increasing the dispersibility of the binder, the conductive additive and the electrode active material in the composite particles, the water content in the solvent contained in the raw material liquid is 100 ppm or less. It is preferable. When the ratio of the water | moisture content in a solvent exceeds 100 ppm, the water | moisture content adsorb | sucked to a composite particle will increase, and it exists in the tendency for the loss by the side reaction in an electrochemical reaction to increase.

  Furthermore, the present invention may further include a particle storage step of sealing the obtained composite particles for an electrode in a sealed case in an inert gas atmosphere after the granulation step. Good. Thereby, it becomes possible to hold the cleaned surface of the electrode active material (carbon material) contained in the manufactured composite particle for an electrode more reliably.

Further, the present invention provides a method for producing an electrode having at least a conductive active material-containing layer containing an electrode active material and a conductive current collector disposed in electrical contact with the active material-containing layer Because
A composite particle forming step of forming the composite particle for an electrode by any one of the methods for producing the composite particle for an electrode of the present invention described above;
An active material-containing layer forming step of forming an active material-containing layer using composite particles at a site where an active material-containing layer of the current collector is to be formed;
Have
Performing an active material-containing layer formation step after the plasma treatment step of the composite particle formation step in an inert gas atmosphere;
An electrode manufacturing method is provided.

  Thus, an electrode capable of sufficiently reducing the irreversible capacity by forming the active material-containing layer using the composite particles for electrodes obtained by the method for producing composite particles for electrodes of the present invention described above. Can be obtained.

  In the method for producing an electrode of the present invention, the active material-containing layer forming step is a sheeting step of obtaining a sheet containing at least the composite particles by subjecting the powder containing at least the composite particles to heat treatment and pressure treatment to form a sheet. And an active material-containing layer disposing step of disposing the sheet as an active material-containing layer on the current collector. Thus, even if the dry method is employed, an electrode having excellent electrode characteristics that can sufficiently reduce the irreversible capacity described above can be obtained more reliably.

  Here, the “powder containing at least composite particles” may be composed of only composite particles. The “powder containing at least the composite particles” may further contain a binder and / or a conductive aid. Thus, when constituents other than the composite particles are included in the powder, the ratio of the composite particles in the powder is preferably 80% by mass or more based on the total mass of the powder.

  Moreover, in the manufacturing method of the electrode of this invention, it is preferable to perform a sheet forming process using a hot roll press machine. The hot roll press machine has a pair of hot rolls, and a “powder containing at least composite particles” is put between the pair of hot rolls, and heated and pressed to form a sheet. Is. Thereby, the sheet | seat used as an active material content layer can be formed easily and reliably.

  As described above, in the method for producing an electrode of the present invention, the active material-containing layer may be formed by a dry method using composite particles in the active material-containing layer forming step. Even if the containing layer is formed, the effects of the present invention described above can be obtained.

  That is, in the method for producing an electrode of the present invention, the active material-containing layer forming step includes a coating liquid preparation step in which the composite particles are added to a liquid in which the composite particles can be dispersed or kneaded to prepare a coating liquid for electrode formation, A step of applying an electrode-forming coating solution to a portion of the current collector where the active material-containing layer is to be formed, and an electrode-forming coating solution applied to the portion of the current collector where the active material-containing layer is to be formed And a step of solidifying the liquid film.

  Also in this case, an electrode having excellent electrode characteristics capable of sufficiently reducing the irreversible capacity can be obtained easily and reliably. Here, the “liquid capable of dispersing the composite particles” is preferably a liquid that does not dissolve the binder in the composite particles, but in the process of forming the active material-containing layer, the electrical contact between the composite particles As long as it is within a range that can sufficiently secure the effect of the present invention, it may have a property of partially dissolving the binder near the surface of the composite particles. As long as the effects of the present invention can be obtained, a binder and a conductive additive may be further added as other components of the composite particles to the liquid in which the composite particles can be dispersed. The binder added as another component in this case is a binder that can be dissolved in the “liquid capable of dispersing composite particles”.

  In addition, in the active material-containing layer forming step, when a liquid capable of kneading the composite particles is used, a kneaded material preparation step of adding a composite particle to the liquid to prepare a kneaded material for forming an electrode including the composite particles; A step of applying the electrode-forming kneaded material to a portion of the current collector where the active material-containing layer is to be formed, and a coating comprising the electrode-forming kneaded material applied to the portion of the current collector where the active material-containing layer is to be formed. And a step of solidifying the film.

  Also in this case, an electrode having excellent electrode characteristics capable of sufficiently reducing the irreversible capacity can be obtained easily and reliably.

  Moreover, the method for producing an electrode of the present invention further includes an electrode storage step of sealing the obtained electrode in a storable case in a sealed state in an inert gas atmosphere after the active material-containing layer forming step. , May be characterized. Thereby, it becomes possible to hold the cleaned surface of the electrode active material (carbon material or metal oxide) in the composite particles for an electrode contained in the manufactured electrode more reliably.

Furthermore, the present invention provides an electrochemical element manufacturing method comprising at least an anode, a cathode, and an electrolyte layer having ionic conductivity, wherein the anode and the cathode are arranged to face each other via the electrolyte layer. There,
As an electrode of at least one of the anode and the cathode, it has an electrode forming step of forming an electrode by any of the above-described methods for producing an electrode of the present invention,
Producing the electrode obtained by the electrode forming step in an inert gas atmosphere;
The manufacturing method of the electrochemical element characterized by this is provided.

  By using the electrode obtained by the above-described electrode manufacturing method of the present invention as at least one of the anode and the cathode, preferably both, excellent charge / discharge characteristics capable of sufficiently reducing the irreversible capacity are obtained. The electrochemical element which has can be obtained easily and reliably.

  Here, in the present specification, the “electrochemical element” includes at least a first electrode (anode) and a second electrode (cathode) that face each other, and the first electrode and the second electrode The thing which has the structure provided with the electrolyte layer which has an ionic conductivity arrange | positioned between these electrodes at least is shown. In addition, the “electrolyte layer having ion conductivity” is (1) a porous separator formed of an insulating material, and an electrolyte solution (or a gelling agent is added to the electrolyte solution). (A gel-like electrolyte obtained) impregnated, (2) a solid electrolyte membrane (a membrane made of a solid polymer electrolyte or a membrane containing an ion conductive inorganic material), (3) a gelling agent is added to the electrolyte solution The layer which consists of a gel-like electrolyte obtained by doing, (4) The layer which consists of electrolyte solution is shown.

  Note that, in any case of the above configurations (1) to (4), the first electrode and the second electrode may have a configuration in which the electrolyte used for each is contained. Good.

  Further, in the present specification, in the configurations of (1) to (3), a laminated body composed of the first electrode (anode), the electrolyte layer, and the second electrode (cathode) is referred to as “element body” as necessary. " Further, the element body has a structure of five layers or more in which the electrodes and the electrolyte layers are alternately laminated in addition to the three-layer structure as in the structures (1) to (3). Also good.

  Further, in any case of the above configurations (1) to (4), the electrochemical element may have a module configuration in which a plurality of unit cells are arranged in series or in parallel in one case. Good.

  The electrochemical element obtained by the method for producing an electrochemical element of the present invention may be characterized in that the electrolyte layer is made of a solid electrolyte. In this case, the solid electrolyte may be a ceramic solid electrolyte, a solid polymer electrolyte, or a gel electrolyte obtained by adding a gelling agent to a liquid electrolyte.

  In this case, an electrochemical element whose constituent elements are all solid (for example, a so-called “all-solid battery”) can be configured. Thereby, weight reduction of an electrochemical element, improvement of energy density, and improvement of safety can be achieved more easily.

  When an “all solid state battery” is configured as an electrochemical element (particularly when an all solid state lithium ion secondary battery is configured), the following advantages (I) to (IV) are obtained. That is, (I) since the electrolyte layer is made of a solid electrolyte instead of a liquid electrolyte, there is no occurrence of liquid leakage and excellent heat resistance (high temperature stability) can be obtained, and the reaction between the electrolyte component and the electrode active material Can be sufficiently prevented. As a result, excellent battery safety and reliability can be obtained. (II) It is possible to easily use metallic lithium, which is difficult in an electrolyte layer made of a liquid electrolytic solution, as an anode (to constitute a so-called “metallic lithium secondary battery”), and to further improve the energy density. be able to. (III) In the case of configuring a module in which a plurality of unit cells are arranged in one case, a plurality of unit cells that cannot be realized with an electrolyte layer made of a liquid electrolyte can be connected in series. Therefore, it is possible to configure a module having various output voltages, particularly a relatively large output voltage. (IV) Compared with the case where an electrolyte layer made of a liquid electrolyte is provided, the degree of freedom of battery shape that can be adopted is widened, and the battery can be easily made compact. Therefore, it can be easily adapted to installation conditions (installation position, size of installation space, and shape of installation space, etc.) in a device such as a portable device mounted as a power source.

  In the method for producing an electrochemical element of the present invention, the electrolyte layer may be composed of a separator made of an insulating porous body and a liquid electrolyte or a solid electrolyte impregnated in the separator. . Also in this case, when a solid electrolyte is used, a gel solid electrolyte obtained by adding a gelling agent to a ceramic solid electrolyte, a solid polymer electrolyte, or a liquid electrolyte can be used.

The present invention also provides a plasma processing unit for performing plasma processing to obtain particles made of an electrode active material having electron conductivity by subjecting a raw material made of a carbonaceous material to high-frequency thermal plasma processing in a plasma gas atmosphere. ,
In an inert gas atmosphere, a conductive assistant and a binder capable of binding the electrode active material and the conductive assistant are adhered to particles made of the electrode active material obtained after the plasma treatment. By integrating, a granulation treatment unit that performs a granulation treatment to form composite particles for an electrode including an electrode active material, a conductive additive, and a binder;
An inert gas atmosphere forming means for performing the granulation treatment in an inert gas atmosphere;
Having
An apparatus for producing composite particles for an electrode is provided.

  As described above, the active material using the composite particles for electrodes obtained by providing the granulation processing section and the inert gas atmosphere forming means operating based on the method for producing composite particles for electrodes of the present invention described above. By forming the containing layer, it is possible to easily and surely obtain electrode composite particles capable of sufficiently reducing the irreversible capacity.

  Furthermore, the composite particle manufacturing apparatus for an electrode of the present invention performs a particle storage process in which the composite particle for an electrode obtained is sealed in a case that can be stored in a sealed state in the inert gas atmosphere after the granulation process. A particle storage processing unit may be further provided. Thereby, it becomes possible to hold the cleaned surface of the electrode active material (carbon material or metal oxide) contained in the manufactured composite particle for electrode more reliably.

In addition, the present invention produces an electrode having at least a conductive active material-containing layer containing an electrode active material and a conductive current collector disposed in electrical contact with the active material-containing layer. An electrode manufacturing apparatus for
A plasma processing unit that performs plasma processing to obtain particles made of an electrode active material having electron conductivity by performing high-frequency thermal plasma processing on a raw material made of a carbonaceous material in a plasma gas atmosphere;
In an inert gas atmosphere, a conductive assistant and a binder capable of binding the electrode active material and the conductive assistant are adhered to particles made of the electrode active material obtained after the plasma treatment. By integrating, a granulation treatment unit that performs a granulation treatment to form composite particles for an electrode including an electrode active material, a conductive additive, and a binder;
An active material-containing layer forming treatment unit that forms an active material-containing layer using composite particles at a site where an active material-containing layer of the current collector is to be formed;
An inert gas atmosphere forming means for performing the treatment in the granulation treatment section and the treatment in the active material-containing layer formation treatment section in an inert gas atmosphere;
Having
An electrode manufacturing apparatus is provided.

  As described above, the plasma processing unit, the granulation processing unit, the active material-containing layer formation processing unit, and the inactive method that operate based on the method for manufacturing composite particles for electrodes of the present invention and the method for manufacturing electrodes of the present invention described above. By providing the gas atmosphere forming means, an electrode capable of sufficiently reducing the irreversible capacity can be obtained easily and reliably.

  Furthermore, the electrode manufacturing apparatus of the present invention is sealed in a case that can be stored in a sealed state in the inert gas atmosphere after the active material-containing layer is formed in the active material-containing layer formation processing unit. And an electrode storage processing unit that performs the electrode storage processing. Thereby, the cleaned surface of the electrode active material (carbon material or metal oxide) in the composite particles for electrodes contained in the active material-containing layer of the manufactured electrode can be more reliably retained.

The present invention also includes at least an anode, a cathode, and an electrolyte layer having ionic conductivity, the anode and the cathode are arranged to face each other with the electrolyte layer interposed therebetween, and the anode and the cathode Manufactures an electrochemical device having a configuration having at least a conductive active material-containing layer containing an electrode active material and a conductive current collector disposed in electrical contact with the active material-containing layer An electrochemical device manufacturing apparatus for
A plasma processing unit that performs plasma processing to obtain particles made of an electrode active material having electron conductivity by performing high-frequency thermal plasma processing on a raw material made of a carbonaceous material in a plasma gas atmosphere;
In an inert gas atmosphere, a conductive assistant and a binder capable of binding the electrode active material and the conductive assistant are adhered to particles made of the electrode active material obtained after the plasma treatment. By integrating, a granulation treatment unit that performs a granulation treatment to form composite particles for an electrode including an electrode active material, a conductive additive, and a binder;
An active material-containing layer forming treatment unit that forms an active material-containing layer using composite particles at a site where an active material-containing layer of the current collector is to be formed;
An element assembly processing unit for assembling an electrochemical element by using a laminate of a current collector and an active material-containing layer as an electrode of at least one of an anode and a cathode;
An inert gas atmosphere forming means for performing processing in the granulation processing section, processing in the active material-containing layer formation processing section, and processing in the element assembly processing section in an inert gas atmosphere;
Having
An electrochemical device manufacturing apparatus is provided.

  Thus, the plasma processing unit, the granulation processing unit that operates based on the method for manufacturing composite particles for electrodes of the present invention, the method for manufacturing electrodes of the present invention, and the method for manufacturing electrochemical devices of the present invention described above, By providing the active material-containing layer forming processing section, the element assembly processing section, and the inert gas atmosphere forming means, an electrochemical element capable of sufficiently reducing the irreversible capacity can be obtained easily and reliably.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the composite particle for electrodes which can fully reduce an irreversible capacity | capacitance can be provided.

  Moreover, according to this invention, the manufacturing method of the electrode which can fully reduce an irreversible capacity | capacitance can be provided.

  Furthermore, according to the present invention, an irreversible capacity can be sufficiently reduced, and a method for producing an electrochemical device capable of obtaining sufficient reversible capacity and charge / discharge efficiency (particularly, initial charge / discharge efficiency) can be provided.

  Moreover, according to this invention, the composite particle manufacturing apparatus for electrodes which can manufacture the composite particle for electrodes which can fully reduce an irreversible capacity | capacitance easily and reliably can be provided.

  Furthermore, according to the present invention, it is possible to provide an electrode manufacturing apparatus capable of easily and reliably manufacturing an electrode capable of sufficiently reducing the irreversible capacity.

  In addition, according to the present invention, the irreversible capacity is sufficiently reduced, and an electrochemical element capable of easily and reliably producing an electrochemical element capable of obtaining sufficient reversible capacity and charge / discharge efficiency (particularly, initial charge / discharge efficiency). An element manufacturing apparatus can be provided.

  Hereinafter, preferred embodiments of the lithium ion secondary battery of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  A preferred basic configuration of an electrochemical device produced by a preferred embodiment of the production method of the present invention and the production apparatus of the present invention will be described. FIG. 1 is a front view showing a basic configuration of an example of an electrochemical element (lithium ion secondary battery) manufactured by a preferred embodiment of the manufacturing method of the present invention. FIG. 2 is a development view when the inside of the electrochemical element shown in FIG. 1 is viewed from the normal direction of the surface of the anode 10. 3 is a schematic cross-sectional view of the electrochemical device shown in FIG. 1 cut along the line X1-X1 of FIG. FIG. 4 is a schematic cross-sectional view showing the main part when the electrochemical device shown in FIG. 1 is cut along the line X2-X2 in FIG. 5 is a schematic cross-sectional view showing the main part when the electrochemical device shown in FIG. 1 is cut along the line YY of FIG.

  As shown in FIGS. 1 to 5, the lithium ion secondary battery 1 is mainly disposed adjacent to each other between a plate-like anode 10 and a plate-like cathode 20 facing each other, and the anode 10 and the cathode 20. A plate-like electrolyte layer 40 (separator or the like), a non-aqueous electrolyte solution, a case 50 containing these in a sealed state, and one end electrically connected to the anode 10 and the other end Is composed of an anode lead 12 protruding outside the case 50 and a cathode lead 22 having one end electrically connected to the cathode 20 and the other end protruding outside the case 50. Has been. Here, the “anode” 10 and the “cathode” 20 are determined based on the polarity at the time of discharging of the lithium ion secondary battery 1 for the convenience of explanation. Accordingly, during charging, “anode 10” becomes “cathode” and “cathode 20” becomes “anode”.

  And the lithium ion secondary battery 1 has the structure demonstrated below, in order to achieve the objective of this invention described previously. Details of each component of the present embodiment will be described below with reference to FIGS.

  The case 50 is formed by using a pair of films (a first film 51 and a second film 52) that face each other. Here, as shown in FIG. 2, the first film 51 and the second film 52 in this embodiment are connected. That is, the case 50 in the present embodiment is formed by folding a rectangular film made of a single composite packaging film along a fold line X3-X3 shown in FIG. 2 and a pair of edges of the rectangular film facing each other ( The edge 51B of the first film 51 and the edge 52B of the second film 52 in the figure are overlapped to form an adhesive or heat seal.

  And the 1st film 51 and the 2nd film 52 respectively show the part of this film which has a mutually opposing surface formed when the sheet-like rectangular film 53 is bend | folded as mentioned above. Here, in this specification, each edge part of the 1st film 51 after bonding and the 2nd film 52 is called "seal part."

  Thereby, since it becomes unnecessary to provide the seal part for joining the 1st film 51 and the 2nd film 52 in the part of bending line X3-X3, the seal part in case 50 can be reduced more. As a result, the volume energy density based on the volume of the space in which the lithium ion secondary battery 1 should be installed can be further improved.

  In the case of the present embodiment, as shown in FIGS. 1 and 2, one end of each of the anode lead 12 and the cathode lead 22 connected to the anode 10 is the edge portion 51 </ b> B of the first film 51 described above. And the edge portion 52B of the second film are arranged so as to protrude to the outside from the sealed portion.

  Moreover, the film which comprises the 1st film 51 and the 2nd film 52 is a film which has flexibility as stated above. Since the film is lightweight and easy to thin, the shape of the lithium ion secondary battery itself can be made into a thin film. Therefore, the original volume energy density can be easily improved, and the volume energy density based on the volume of the space in which the lithium ion secondary battery is to be installed can be easily improved.

  The film is not particularly limited as long as it is a flexible film. However, while ensuring sufficient mechanical strength and light weight of the case, moisture and air intrusion into the case 50 from the outside of the case 50 and the inside of the case 50 can be achieved. From the viewpoint of effectively preventing the electrolyte component from escaping to the outside of the case 50, an innermost layer made of a synthetic resin that comes into contact with the nonaqueous electrolyte solution, and a metal layer disposed above the innermost layer, It is preferably a “composite packaging film” having at least

  Examples of the composite packaging film that can be used as the first film 51 and the second film 52 include a composite packaging film having a configuration shown in FIGS. 6 and 7. The composite packaging film 53 shown in FIG. 6 is disposed on the innermost layer 50a made of a synthetic resin that comes into contact with the nonaqueous electrolyte solution on the inner surface F53, and on the other surface (outer surface) of the innermost layer 50a. And a metal layer 50c. Further, the composite packaging film 54 shown in FIG. 7 has a configuration in which an outermost layer 50b made of synthetic resin is further arranged on the outer surface of the metal layer 50c of the composite packaging film 53 shown in FIG.

  The composite packaging film that can be used as the first film 51 and the second film 52 includes two or more layers including one or more synthetic resin layers including the innermost layer described above and a metal layer such as a metal foil. Although it will not specifically limit if it is the composite packaging material which has a layer, From the viewpoint of acquiring the same effect as the above more reliably, like the composite packaging film 54 shown in FIG. Synthetic resin outermost layer 50b disposed on the outer surface side of case 50 furthest from layer 50a, and at least one metal layer disposed between innermost layer 50a and outermost layer 50b More preferably, it is composed of three or more layers having 50c.

  The innermost layer 50a is a layer having flexibility, and the constituent material thereof can express the above-mentioned flexibility, and the chemical stability (chemical properties) with respect to the non-aqueous electrolyte solution 30 to be used. It is not particularly limited as long as it is a synthetic resin having a chemical stability with respect to oxygen and water (moisture in the air), and oxygen, water (in the air) A material having a property of low permeability to moisture and components of the non-aqueous electrolyte solution 30 is preferable. Examples thereof include thermoplastic resins such as polyethylene, polypropylene, polyethylene acid modified product, polypropylene acid modified product, polyethylene ionomer, and polypropylene ionomer.

  Further, when a synthetic resin layer such as the outermost layer 50b is further provided in addition to the innermost layer 50a as in the composite packaging film 54 shown in FIG. Constituent materials similar to the innermost layer 50a may be used.

  The metal layer 50c is preferably a layer formed of a metal material having corrosion resistance against oxygen, water (water in the air) and a non-aqueous electrolyte solution. For example, a metal foil made of aluminum, aluminum alloy, titanium, chromium, or the like may be used.

  Moreover, the sealing method of all the sealing parts in the case 50 is not particularly limited, but the heat sealing method is preferable from the viewpoint of productivity.

  Next, the anode 10 and the cathode 20 will be described. FIG. 8 is a schematic cross-sectional view showing an example of the basic configuration of the anode of the lithium ion secondary battery shown in FIG. FIG. 9 is a schematic cross-sectional view showing an example of the basic configuration of the cathode of the lithium ion secondary battery shown in FIG.

  As shown in FIG. 8, the anode 10 includes a current collector 16 and an anode active material-containing layer 18 formed on the current collector 16. As shown in FIG. 9, the cathode 20 includes a current collector 26 and a cathode active material-containing layer 28 formed on the current collector 26.

  The current collector 16 and the current collector 26 are not particularly limited as long as they are good conductors that can sufficiently transfer charges to the anode active material-containing layer 18 and the cathode active material-containing layer 28. The current collector used for the secondary battery can be used. For example, the current collector 16 and the current collector 26 include metal foils such as aluminum and copper.

  Further, the active material-containing layer 18 of the anode 10 is mainly composed of composite particles P10 shown in FIG. FIG. 10 is a schematic cross-sectional view showing an example of the basic configuration of composite particles produced in the granulation step in the production method of the present invention. Further, the composite particles P10 are composed of particles P1 made of an electrode active material, particles P2 made of a conductive additive, and particles P3 made of a binder. The average particle size of the composite particles P10 is not particularly limited. The composite particle P10 has a structure in which particles P1 made of an electrode active material and particles P2 made of a conductive additive are electrically coupled without being isolated. Therefore, also in the active material-containing layer 18, a structure is formed in which the particles P1 made of the electrode active material and the particles P2 made of the conductive auxiliary agent are electrically isolated without being isolated.

The electrode active material constituting the composite particle P10 contained in the anode 10 is not particularly limited, and a known electrode active material may be used. For example, carbon materials such as graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, etc. that can occlude / release lithium ions (intercalation or doping / dedoping), lithium such as Al, Si, Sn, etc. Metal, an amorphous compound mainly composed of oxides such as SiO ₂ and SnO ₂ , lithium titanate (Li ₃ Ti ₅ O ₁₂ ), and the like.

  The conductive aid constituting the composite particle P10 contained in the anode 10 is not particularly limited, and a known conductive aid may be used. For example, carbon blacks, carbon materials such as highly crystalline artificial graphite and natural graphite, metal fine powders such as copper, nickel, stainless steel and iron, mixtures of the above carbon materials and metal fine powders, conductive oxides such as ITO Can be mentioned.

  The binder constituting the composite particle P10 included in the anode 10 is not particularly limited as long as it can bind the electrode active material particles and the particles P2 made of a conductive additive. For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoro Examples thereof include fluorine resins such as ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and polyvinyl fluoride (PVF). The binder not only binds the particles P1 made of the electrode active material and the particles P2 made of the conductive additive, but also binds the foil (current collector 24) and the composite particles P10. It also contributes.

  In addition to the above, the binder may be, for example, vinylidene fluoride-hexafluoropropylene-based fluororubber (VDF-HFP-based fluororubber), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene-based fluororubber (VDF- HFP-TFE fluorine rubber), vinylidene fluoride-pentafluoropropylene fluorine rubber (VDF-PFP fluorine rubber), vinylidene fluoride-pentafluoropropylene-tetrafluoroethylene fluorine rubber (VDF-PFP-TFE fluorine rubber) ), Vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene fluorine rubber (VDF-PFMVE-TFE fluorine rubber), vinylidene fluoride-chlorotrifluoroethylene fluorine rubber It may be used vinylidene fluoride fluoroelastomer of the VDF-CTFE-based fluorine rubber) and the like.

  In addition to the above, as the binder, for example, polyethylene, polypropylene, polyethylene terephthalate, aromatic polyamide, cellulose, styrene / butadiene rubber, isoprene rubber, butadiene rubber, ethylene / propylene rubber, or the like may be used. Also, thermoplastic elastomeric polymers such as styrene / butadiene / styrene block copolymers, hydrogenated products thereof, styrene / ethylene / butadiene / styrene copolymers, styrene / isoprene / styrene block copolymers, and hydrogenated products thereof. May be used. Further, syndiotactic 1,2-polybutadiene, ethylene / vinyl acetate copolymer, propylene / α-olefin (carbon number 2 to 12) copolymer and the like may be used. Further, a conductive polymer may be used.

  Moreover, you may further add to the composite particle P10 the particle | grains which consist of an electroconductive polymer as a structural component of the said composite particle P10. Furthermore, when forming an electrode by a dry method using the composite particle P10, it may be added as a constituent component of a powder containing at least the composite particle. Further, when forming an electrode by a wet method using the composite particles P10, when preparing a coating solution or kneaded product containing the composite particles P10, particles made of a conductive polymer are added to the coating solution or kneaded product. It may be added as a constituent material.

For example, the conductive polymer is not particularly limited as long as it has lithium ion conductivity. For example, polymer compounds (polyether-based polymer compounds such as polyethylene oxide and polypropylene oxide, crosslinked polymers of polyether compounds, polyepichlorohydrin, polyphosphazene, polysiloxane, polyvinylpyrrolidone, polyvinylidene carbonate, polyacrylonitrile, etc.) Monomer and an alkali metal salt mainly composed of LiClO ₄ , LiBF ₄ , LiPF ₆ , LiAsF ₆ , LiCl, LiBr, Li (CF ₃ SO ₂ ) ₂ N, LiN (C ₂ F ₅ SO ₂ ) ₂ lithium salt And the like. Examples of the polymerization initiator used for the combination include a photopolymerization initiator or a thermal polymerization initiator that is compatible with the above-described monomer.

  When the secondary battery 1 is a metal lithium secondary battery, the anode (not shown) may be an electrode made of only metal lithium or a lithium alloy that also serves as a current collector. The lithium alloy is not particularly limited, and examples thereof include alloys such as Li—Al, LiSi, and LiSn (here, LiSi is also handled as an alloy). In this case, the cathode is configured using composite particles P10 having a configuration described later.

  The cathode 20 of the secondary battery 1 shown in FIG. 1 includes a film-like current collector 34 and a film-like active material containing layer 28 disposed between the current collector 34 and the electrolyte layer 40. Yes. The cathode 20 is connected to a cathode (none of which is shown) of an external power source during charging and functions as an anode. The shape of the cathode 20 is not particularly limited, and may be, for example, a thin film as illustrated. For example, an aluminum foil is used as the current collector 34 of the cathode 20.

The electrode active material constituting the composite particle P10 contained in the cathode 20 is not particularly limited, and a known electrode active material may be used. For example, lithium cobalt oxide (LiCoO _2), lithium nickel oxide (LiNiO _2), lithium manganese spinel (LiMn ₂ O _4), and the general formula: represented by _{LiNi x Mn y Co z O 2} (x + y + z = 1) Examples include composite metal oxides, lithium vanadium compounds, V ₂ O ₅ , olivine-type LiMPO ₄ (wherein M represents Co, Ni, Mn, or Fe), lithium titanate ((Li ₃ Ti ₅ O ₁₂ ), and the like. It is done.

  Furthermore, each component other than the electrode active material constituting the composite particle P10 contained in the cathode 20 can use the same material as that constituting the composite particle P10 contained in the anode 10. In addition, the binder constituting the composite particle P10 contained in the cathode 20 not only binds the particle P1 made of the electrode active material and the particle P2 made of the conductive assistant, but also a foil (current collector 34). ) And the composite particle P10. As described above, the composite particle P10 has a structure in which the particle P1 made of an electrode active material and the particle P2 made of a conductive additive are electrically isolated without being isolated. Therefore, also in the active material containing layer 28, a structure is formed in which the particles P1 made of the electrode active material and the particles P2 made of the conductive assistant are electrically isolated without being isolated.

Here, from the viewpoint of forming a contact interface with the conductive auxiliary agent, the electrode active material, and the solid polymer electrolyte in a three-dimensional and sufficient size, each electrode active material included in each of the anode 10 and the cathode 20 described above. In the case of the cathode 20, the BET specific surface area of the particles P1 made of is preferably 0.1 to 1.0 m ² / g, and more preferably 0.1 to 0.6 m ² / g. It is preferable that when the anode 10 is 0.1 to 10 m ² / g, more preferably 0.1 to 5 m ² / g. When the electrochemical element is a double layer capacitor, both the cathode 20 and the anode 10 are preferably 500 to 3000 m ² / g.

  Furthermore, from the same viewpoint, the average particle diameter of the particles P1 made of each electrode active material is preferably 5 to 20 μm, more preferably 5 to 15 μm in the case of the cathode 20. Moreover, in the case of the anode 10, it is preferable that it is 1-50 micrometers, and it is more preferable that it is 1-30 micrometers. Furthermore, from the same point of view, the amount of the conductive assistant and the binder adhering to the electrode active material is a value of 100 × (mass of conductive assistant + mass of binder) / (mass of electrode active material). When expressed, it is preferably 1 to 30% by mass, and more preferably 3 to 15% by mass.

  The electrolyte layer 40 may be a layer made of an electrolytic solution, a layer made of a solid electrolyte (ceramic solid electrolyte, solid polymer electrolyte), an electrolyte solution impregnated in the separator and / or Alternatively, it may be a layer made of a solid electrolyte.

The electrolytic solution 30 is prepared by dissolving a lithium-containing electrolyte in a non-aqueous solvent. The lithium-containing electrolyte may be appropriately selected from, for example, LiClO ₄ , LiBF ₄ , LiPF _6, etc., and Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, etc. Lithium imide salt, LiB (C ₂ O ₄ ) ₂ or the like can also be used. The non-aqueous solvent can be selected from, for example, ethers, ketones, carbonates and the like, and organic solvents exemplified in JP-A No. 63-121260, but in the present invention, carbonates are particularly used. Is preferred. Among carbonates, it is particularly preferable to use a mixed solvent in which ethylene carbonate is the main component and one or more other solvents are added. Usually, the mixing ratio is preferably ethylene carbonate: other solvent = 5 to 70:95 to 30 (volume ratio). Since ethylene carbonate has a high freezing point of 36.4 ° C and is solidified at room temperature, ethylene carbonate alone cannot be used as a battery electrolyte, but it can be mixed by adding one or more other solvents having a low freezing point. The freezing point of the solvent is lowered and it can be used. In this case, any other solvent may be used as long as it lowers the freezing point of ethylene carbonate. For example, diethyl carbonate, dimethyl carbonate, propylene carbonate, 1,2-dimethoxyethane, methyl ethyl carbonate, γ-butyrolactone, γ-parerolactone, γ-octanoic lactone, 1,2-diethoxyethane, 1,2-ethoxymethoxy Examples include ethane, 1,2-dibutoxyethane, 1,3-dioxolanane, tetrahydrofuran, 2-methyltetrahydrofuran, 4,4-dimethyl-1,3-dioxane, butylene carbonate, and methyl formate. By using a carbonaceous material as the active material of the anode and using the above mixed solvent, the battery capacity is remarkably improved, and the irreversible capacity ratio can be sufficiently lowered.

  Examples of the solid polymer electrolyte include a conductive polymer having ionic conductivity.

The conductive polymer is not particularly limited as long as it has lithium ion conductivity. For example, polymer compounds (polyether polymer compounds such as polyethylene oxide and polypropylene oxide, and high cross-linked polymers of polyether compounds) Molecules, polyepichlorohydrin, polyphosphazene, polysiloxane, polyvinylpyrrolidone, polyvinylidene carbonate, polyacrylonitrile, etc.) monomers, and LiClO ₄ , LiBF ₄ , LiPF ₆ , LiAsF ₆ , LiCl, LiBr, Li (CF ₃ SO ₂ ) ₂ N, LiN (C ₂ F ₅ SO ₂ ) ₂ Lithium salt or a composite of an alkali metal salt mainly composed of lithium and the like can be mentioned. Examples of the polymerization initiator used for the combination include a photopolymerization initiator or a thermal polymerization initiator that is compatible with the above-described monomer.

Further, as the supporting salt constituting the polymer solid electrolyte, for example, LiClO ₄ , LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CF ₂ SO ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ) and a salt such as LiN (CF ₃ CF ₂ CO) ₂ , or These mixtures are mentioned.

  In the case of using a separator for the electrolyte layer 40, the constituent material thereof is, for example, one or more polyolefins such as polyethylene and polypropylene (in the case of two or more, there is a laminate of two or more layers). And polyesters such as polyethylene terephthalate, thermoplastic fluororesins such as ethylene-tetrafluoroethylene copolymer, and celluloses. The form of the sheet includes a microporous membrane film, a woven fabric, a non-woven fabric, etc. having an air permeability measured by the method specified in JIS-P8117 of about 5 to 2000 sec / 100 cc and a thickness of about 5 to 100 μm. A solid electrolyte monomer may be impregnated into a separator and cured to be polymerized. Moreover, you may use it, making the electrolyte solution mentioned above contain in a porous separator.

  The electrochemical device (lithium ion secondary battery) described above can be produced according to the method for producing composite particles for an electrode, the method for producing an electrode, and the method for producing an electrochemical device of the present invention. Moreover, the electrochemical element (lithium ion secondary battery) demonstrated above has the mechanism which operate | moves based on each manufacturing method of the said invention, The composite particle manufacturing apparatus for electrodes of this invention, an electrode manufacturing apparatus, and It can manufacture with the manufacturing apparatus of an electrochemical element.

  Next, a preferred embodiment of each manufacturing method of the present invention and each manufacturing apparatus of the present invention will be described.

  FIG. 11 is an explanatory diagram showing the basic configuration of a preferred embodiment of the electrochemical device manufacturing apparatus of the present invention. 11 mainly includes a plasma processing unit 91, a granulation processing unit 92, an active material containing layer formation processing unit 93, an element assembly processing unit 94, and an inert gas atmosphere forming means 95. It consists of and. The element assembly processing unit 90 has a mechanism that operates based on each manufacturing method of the present invention.

  Hereinafter, the configurations of the plasma processing unit 91, the granulation processing unit 92, the active material-containing layer formation processing unit 93, the element assembly processing unit 94, and the inert gas atmosphere forming unit 95 will be described in detail, and each operation method at the same time. A preferred embodiment of each manufacturing method of the present invention will be described in detail.

  The inert gas atmosphere forming means 95 has a mechanism for performing all the manufacturing steps after the plasma processing in the plasma processing section 91 described later in an inert gas atmosphere. As an inert gas atmosphere formation means 95, a glove box is mentioned preferably, for example. In the element assembly processing unit 90, all the manufacturing processes after the plasma processing are performed in an inert gas atmosphere by an inert gas atmosphere forming means 95 such as a glove box. For example, the inside of the inert gas atmosphere forming means 95 such as a glove box is filled with an inert gas, the oxygen concentration is adjusted to 1 ppm or less, and the relative humidity is set to 0.04% (dew point temperature of about −60 ° C.) or less. Adjust and perform manufacturing operations.

  In the plasma processing unit 91, a plasma processing step is performed in which, in a plasma gas atmosphere, a raw material made of a carbonaceous material is subjected to high frequency thermal plasma processing to obtain particles made of an electrode active material having electron conductivity. .

  The plasma processing unit 91 is provided with a high-frequency thermal plasma generator (plasma torch). FIG. 12 is a schematic configuration diagram of a high-frequency thermal plasma generator (plasma torch) used for plasma processing.

  First, raw material particles (hereinafter referred to as “raw material particles” made of a carbonaceous material that is a constituent material of the composite particles P10 included in the active material-containing layer 18 of the anode 10 or the composite particles P10 included in the active material-containing layer 28 of the cathode 20. P50 ”). Specifically, high frequency thermal plasma treatment is performed on the raw material particles in a plasma gas atmosphere.

  Here, as the raw material made of the carbonaceous material, the raw material made of the carbonaceous material may be any carbon material having electron conductivity by performing the above-described high-frequency thermal plasma treatment. For example, graphite , Pitch materials, coconut husks, phenol resins, and the like.

  Examples of the raw material made of the carbonaceous material that becomes the electrode active material by the high-frequency thermal plasma treatment include chain vinyl polymers such as phenol resin, acrylic resin, furan resin, polyvinylidene chloride (PVDC), polyacrylonitrile, and the like. And various resins such as polymers composed of biphenyl bonds such as polyphenylene, and nitrogen-containing resins such as polyamides such as polyaniline, polyimide and nylon, and nitrogen-containing phenol resins can also be used. In addition, various saccharides such as polysaccharides can also be used. Of these, phenol resins, particularly true spherical phenol resins are preferred.

  In addition, examples of the raw material made of the other carbonaceous material include graphite, glassy carbon, pyrolytic graphite, carbon fiber, carbon paste, activated carbon, and the like, and activated carbon is particularly preferable. There is no particular limitation as long as it is activated carbon, and raw coal (for example, petroleum coke or resin produced from a delayed coker that uses the bottom oil of a fluid catalytic cracking unit of heavy petroleum oil or the residual oil of a vacuum distillation unit as the raw material oil) It is preferable that the main component is carbonized (such as phenolic resin) or carbonized natural material (such as coconut shell charcoal).

  Among these, MCMB (mesophase carbon microbeads) is particularly preferable. This MCMB is obtained by graphitizing a spherical carbonaceous material obtained from pitch, and is easier to handle in the production of electrode materials than conventional graphite materials. That is, since it is excellent in fluidity, it is suitable for use in high-frequency thermal plasma processing, tends to be capable of mass processing, and excellent in productivity. Moreover, it tends to be easy to form a film when forming an electrode.

  The material used for the high-frequency thermal plasma treatment and the carbonaceous material after the high-frequency thermal plasma treatment are preferably in the form of particles or powder, and the average particle size is preferably about 0.5 to 100 μm. These particles are preferably spherical, but may have a shape other than spherical, for example, a spheroid shape or an indefinite shape.

  The high-frequency thermal plasma treatment is, for example, “Takamasa Ishigaki, Ceramics, 30 (1995) No. 11, 1013 to 1016”, JP-A-7-31873, JP-A-10-92432 and JP-A-2000-223121. Can be done according to.

  A high-frequency thermal plasma generator (thermal plasma torch) 100 shown in FIG. 12 continuously introduces an object into the plasma torch and collects it at the bottom. The high-frequency thermal plasma generator 100 has a configuration in which a high-frequency coil 12 is wound around the outer periphery of a water-cooled double tube 110. Then, high-frequency electromagnetic induction is performed to form thermal plasma inside the water-cooled double tube 110. A lid 130 is attached to the opening located in the upper part of the water-cooled double tube 11, and a powder-feeding water-cooled probe 140 for supplying raw material powder and carrier gas for high-frequency thermal plasma processing is installed on the lid 130. Has been. In addition, a central gas (Gp) for mainly forming a plasma flow and a sheath gas (Gs) for mainly wrapping the outside of the plasma flow are introduced into the apparatus 100.

  In the present invention, the central gas, the sheath gas, and the carrier gas are collectively referred to as “plasma gas”. In this plasma gas atmosphere, high-frequency thermal plasma processing is performed.

Moreover, it is preferable to use at least Ar as the plasma gas, and it is more preferable to use Ar together with at least one of N ₂ , H ₂ , CO ₂ and CO. In particular, it is preferable to use N ₂ or H ₂ in combination with Ar, and to add CO ₂ to these. The content of gas other than Ar in the plasma gas is preferably 1 to 20% by volume with respect to the total amount of plasma gas. The type of gas used for each of the central gas, the sheath gas, and the carrier gas is not particularly limited, but it is preferable that all contain at least Ar. In particular, the sheath gas includes N ₂ or H ₂ in order to protect the inner wall of the torch. It is preferable to mix diatomic gases. When at least H ₂ is used as the plasma gas, the irreversible capacity tends to be reduced and the initial charge / discharge efficiency tends to be more sufficiently improved. The total flow rate of the central gas and the sheath gas is usually 2 to 200 L / min, preferably 30 to 130 L / min.

  Furthermore, the amount of the raw material to be introduced is preferably 1 to 500 g / min, and the flow rate of the carrier gas is preferably 1 to 100 L / min.

In addition, by appropriately selecting the plasma gas, the effect of the high-frequency thermal plasma treatment can be controlled. For example, H ₂ has a higher thermal conductivity than N ₂ , so when H ₂ is used, Usually, the heating efficiency tends to increase.

  The generation conditions of the high-frequency thermal plasma are usually a frequency of 0.5 to 6 MHz, preferably 3 to 6 MHz, an input power of 3 to 60 kW, and a pressure inside the torch of 1 to 100 kPa, preferably 10 to 70 kPa. is there.

  By using such an apparatus 100, high-frequency thermal plasma processing at 3,000 to 15,000 ° C. is possible. In the present invention, the residence time of the raw material in the temperature range of 3,000 to 15,000 ° C. is preferably about 0.001 to 10 seconds, particularly about 0.02 to 0.5 seconds.

  Further, the size of the high-frequency thermal plasma generator 100 (plasma torch) is not particularly limited, but in the case of the structure shown in FIG. 12, the tube diameter is preferably 10 to 1000 mm, and is preferably 50 to 100 mm. Is more preferable, the height is preferably 50 to 3000 mm, and more preferably 200 to 3000 mm.

The raw material may be subjected to high-frequency thermal plasma treatment alone, or may be subjected to high-frequency thermal plasma treatment in a state where oxides are mixed. The oxide used in this case, for example, lithium cobaltate (LiCoO _2), lithium nickelate (LiNiO _2), lithium manganate (LiMnO _2), lithium manganese spinel (LiMn ₂ O _4), lithium vanadium compounds, V ₂ O ₅ , olivine type LiMPO ₄ (M: Co, Ni, Mn, Fe) and the like are preferable. The compounding amount of the oxide is preferably 10% by mass or less based on the total amount of the mixture (raw material + oxide).

  Next, the granulation processing unit 92 will be described. In the granulation processing unit 92, it is possible to bind the conductive assistant, the electrode active material, and the conductive assistant to the particles P1 made of the electrode active material obtained after the plasma treatment in an inert gas atmosphere. By bringing the binder into close contact and integrating, a granulation treatment is performed to form electrode composite particles P10 containing an electrode active material, a conductive additive, and a binder.

  As described above, the composite particle P10 is obtained by bringing the conductive auxiliary agent and the binder into close contact with the particle P1 made of the electrode active material in the granulation treatment unit 92, thereby integrating the electrode active material, the conductive auxiliary agent, and the like. And a granulating step for forming composite particles containing a binder.

  The granulation step includes a raw material solution preparation step for preparing a raw material solution containing a binder, the conductive auxiliary agent, and a solvent, an air flow is generated in the fluidized tank, and particles made of an electrode active material are introduced into the air flow. Then, a fluidized bed forming step of fluidizing the particles made of the electrode active material, and spraying the raw material liquid into the fluidized bed containing the particles made of the electrode active material, thereby attaching the raw material liquid to the particles made of the electrode active material. Spray drying step of drying, removing the solvent from the raw material liquid adhering to the surface of the particles made of the electrode active material, and bringing the particles made of the electrode active material and the particles made of the conductive auxiliary agent into close contact with each other by a binder; including. And the granulation process part 92 is equipped with the mechanism for performing the said raw material liquid preparation process, a fluidized bed formation process, and a spray-drying process.

  The granulation process performed in this granulation process part 92 is demonstrated concretely using FIG. FIG. 13 is an explanatory diagram showing an example of a granulation step when producing composite particles.

  First, in the raw material liquid preparation step, a solvent capable of dissolving the binder is used, and the binder is dissolved in this solvent. Next, a conductive additive is dispersed in the obtained solution to obtain a raw material liquid. In addition, in this raw material liquid preparation process, the solvent (dispersion medium) which can disperse | distribute a binder may be sufficient.

  Next, in the fluidized bed forming step, as shown in FIG. 13, in the fluidized tank 5, an airflow is generated by a predetermined airflow generating means (not shown), and particles P1 made of an electrode active material in the airflow. To make the particles made of the electrode active material fluidized.

  Next, in the spray drying step, as shown in FIG. 13, the raw material liquid droplets 6 are sprayed in the fluidized tank 5 by spraying the raw material liquid droplets 6 by a predetermined spraying means (not shown). It is made to adhere to the particle P1 which consists of the electrode active material formed into the fluidized bed, and it is made to dry at the same time in the fluidized tank 5, and the solvent is removed from the droplet 6 of the raw material liquid adhering to the surface of the particle P1 made of the electrode active material. The particles P1 made of an electrode active material and the particles P2 made of a conductive auxiliary agent are brought into close contact with the agent to obtain composite particles P10.

  More specifically, the fluid tank 5 is, for example, a container having a cylindrical shape, and warm air (or hot air) L5 is introduced into the bottom thereof from the outside, and the electrode active material is contained in the fluid tank 5. An opening 52 for convection of particles consisting of is provided. Further, an opening 54 is provided on the side surface of the fluid tank 5 for allowing the droplets 6 of the raw material liquid to be sprayed to flow into the particles P1 made of the electrode active material convected in the fluid tank 5. ing. The droplets 6 of the raw material liquid containing the binder, the conductive auxiliary agent, and the solvent are sprayed on the particles P1 made of the electrode active material convected in the fluidized tank 5.

  At this time, the temperature of the atmosphere in which the particles P1 made of the electrode active material are placed can be quickly removed by adjusting the temperature of the hot air (or hot air), for example. The electrode is kept at a predetermined temperature (preferably a temperature not exceeding the melting point of the binder substantially from 50 ° C., more preferably a temperature not higher than the melting point of the binder (eg, 200 ° C.)). The liquid film of the raw material liquid formed on the surface of the particles P1 made of the active material is dried almost simultaneously with the spraying of the droplets 6 of the raw material liquid. As a result, the binder and the conductive auxiliary agent are brought into close contact with the surface of the particles made of the electrode active material, thereby obtaining composite particles P10.

  Here, the solvent capable of dissolving the binder is not particularly limited as long as the binder can be dissolved and the conductive auxiliary agent can be dispersed. For example, N-methyl-2-pyrrolidone, N , N-dimethylformamide and the like can be used.

Next, the active material containing layer formation processing unit 93 will be described. In the active material-containing layer formation processing unit, the active material-containing layer is formed by using the composite particles P10 at the site where the active material-containing layer of the current collector is to be formed. More specifically, the active material-containing layer is formed based on a wet method or a dry method described below. The active material-containing layer formation processing unit 93 is provided with a mechanism for forming an active material-containing layer based on a wet method or a dry method described later.
(Wet method)
First, a suitable example in the case of using the composite particles P10 produced through the granulation step described above to prepare an electrode-forming coating solution and using this to form an electrode will be described. First, an example of a method for preparing an electrode forming coating solution will be described.

  The electrode forming coating liquid is, for example, a mixed liquid in which a composite particle P10 produced through a granulation step, a liquid capable of dispersing or dissolving the composite particle P10, and a conductive polymer added as necessary are mixed. And a part of the liquid is removed from the mixed solution and adjusted to a viscosity suitable for coating, whereby an electrode-forming coating solution can be obtained.

  More specifically, when a conductive polymer is used, as shown in FIG. 14, for example, the composite particles P10 are dispersed or dispersed in a container 8 having a predetermined stirring means (not shown) such as a stirrer. A liquid mixture is prepared in which a dissolvable liquid and a conductive polymer or a monomer that is a constituent material of the conductive polymer are mixed. Next, the electrode-forming coating liquid L2 can be prepared by adding the composite particles P10 to the mixed liquid and stirring sufficiently.

  Next, an active material containing layer is formed using the electrode forming coating solution L2.

  First, the electrode forming coating liquid L2 is applied to the surface of the current collector, and a liquid film of the coating liquid is formed on the surface. Next, by drying the liquid film, an active material-containing layer is formed on the current collector to complete the production of the electrode. Here, the method for applying the electrode-forming coating solution to the surface of the current collector is not particularly limited, and may be appropriately determined according to the material, shape, and the like of the current collector. Examples thereof include a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a gravure coating method, and a screen printing method.

  Further, as a method for forming the active material-containing layer from the liquid film of the electrode forming coating liquid L2, when forming the active material-containing layer from the liquid film of the coating liquid L2, in addition to drying, There may be a case in which a curing reaction (for example, a polymerization reaction of a monomer serving as a constituent material of the conductive polymer) is involved between the constituent components. For example, when using the electrode forming coating liquid L2 containing a monomer that is a constituent material of an ultraviolet curable resin (conductive polymer), first, the electrode forming coating liquid L2 is first applied onto the current collector by the above-described predetermined method. Apply by. Next, an active material containing layer is formed by irradiating the liquid film of the coating liquid with ultraviolet rays.

  In this case, a liquid film of the electrode forming coating liquid is formed on the current collector as compared with the case where the conductive polymer (particles made of the conductive polymer) is previously contained in the electrode forming coating liquid L2. After that, the monomer is polymerized in the liquid film to form a conductive polymer, so that the conductive particles P10 are electrically conductive in the gaps between the composite particles P10 while maintaining a good dispersion state of the composite particles P10 in the liquid film. Since the polymer can be generated, the dispersion state of the composite particles P10 and the conductive polymer in the obtained active material-containing layer can be made better.

  That is, an ion conduction network and an electron conduction network in which finer and dense particles (composite particles P10 and particles made of a conductive polymer) are integrated in the obtained active material-containing layer can be constructed. Therefore, in this case, a polymer electrode having excellent polarization characteristics that can sufficiently advance the electrode reaction even in a relatively low operating temperature region can be obtained more easily and more reliably.

  Furthermore, in this case, the polymerization reaction of the monomer that is a constituent material of the ultraviolet curable resin can be advanced by ultraviolet irradiation.

  Further, the obtained active material-containing layer may be subjected to a rolling treatment such as heat treatment using a hot plate press or a hot roll to form a sheet, if necessary.

  In the above description, as an example of an electrode forming method using the composite particles P10, the case where the electrode forming coating solution 7 containing the composite particles P10 is prepared and the electrodes are formed using this is described. The electrode forming method (wet method) using the particles P10 is not limited to this.

  Next, a more specific aspect of the wet method for forming the electrode sheet ES10 shown in FIG. 16 using the electrode forming coating liquid L2 and the apparatus 70 and the apparatus 80 as shown in FIGS. explain. In the following description, an electrode sheet ES10 for the anode 10 (see FIG. 16) and a method for forming the anode 10 obtained from the electrode sheet ES10 will be described, and formation of the cathode 20 having the same configuration as the anode 10 will be described. The method is omitted.

  The apparatus 70 shown in FIG. 15 mainly includes a first roll 71, a second roll 72, a dryer 73 disposed between the first roll 71 and the second roll 72, and two supports. And a roll 79. The first roll 71 is composed of a cylindrical core 74 and a tape-like laminate sheet 75. One end of the laminate sheet 75 is connected to the winding core 74, and the laminate sheet 75 is further wound around the winding core 74. Furthermore, the laminate sheet 75 has a configuration in which the metal foil sheet 16A is laminated on the base sheet B1.

  The second roll 72 has a cylindrical core 76 to which the other end of the laminate sheet 75 is connected. Further, a winding core driving motor (not shown) for rotating the winding core 76 is connected to the winding core 76 of the second roll 72, and a coating liquid L1 for electrode formation is applied and further dried. The laminate sheet 77 after being dried in the machine 73 is wound at a predetermined speed.

  First, when the winding core driving motor rotates, the winding core 76 of the second roll 72 rotates, and the laminate sheet 75 wound around the winding core 74 of the first roll 71 becomes the first roll 71. Pulled out. Next, the electrode forming coating liquid L2 is applied on the metal foil sheet 16A of the drawn laminate sheet 75 (application process). Thereby, the coating film L4 which consists of the electrode forming coating liquid L2 is formed on the metal foil sheet 16A.

  Next, due to the rotation of the winding core driving motor, the portion of the laminate sheet 75 on which the coating film L4 is formed is guided into the dryer 73 by the support roll 79. In the dryer 73, the coating film L <b> 4 on the laminate sheet 75 becomes a layer 78 (hereinafter referred to as “precursor layer 78”) that becomes a precursor of the porous body layer 18 when dried to be an electrode ( Liquid removal step). The laminate sheet 77 in which the precursor layer 78 is formed on the laminate sheet 75 is guided to the core 76 by the support roll 79 and is wound around the core 76 by the rotation of the core driving motor. .

  Next, the electrode sheet ES10 is produced using the laminate sheet 77 and the apparatus 80 shown in FIG.

  The apparatus 80 shown in FIG. 16 mainly includes a first roll 81, a second roll 82, and a roll press machine 83 disposed between the first roll 81 and the second roll 82. ing. The first roll 81 is composed of a cylindrical core 84 and the tape-shaped laminate sheet 77 described above. One end of the laminate sheet 77 is connected to the core 84, and the laminate sheet 77 is further wound around the core 84. The laminate sheet 77 has a configuration in which a precursor layer 78 is further laminated on a laminate sheet 75 in which the metal foil sheet 16A is laminated on the base sheet B1.

  The second roll 82 has a cylindrical core 86 to which the other end of the laminate sheet 77 is connected. Further, a winding core driving motor (not shown) for rotating the winding core 86 is connected to the winding core 86 of the second roll 82, and press processing was performed in the roll press machine 83. The subsequent laminate sheet 87 is wound at a predetermined speed.

  First, when the winding core driving motor rotates, the winding core 86 of the second roll 82 rotates, and the laminate sheet 77 wound around the winding core 84 of the first roll 81 becomes the first roll 81. Pulled out. Next, the laminate sheet 77 is guided into the roll press machine 83 by the rotation of the core driving motor. In the roll press machine 83, two cylindrical rollers 83A and 83B are arranged. The roller 83A and the roller 83B are arranged so that the laminate sheet 77 is inserted between them, and when the laminate sheet 77 is inserted between them, the side surface of the roller 83A and the laminate sheet 77, the outer surface of the precursor layer 78 is in contact, the side surface of the roller 83B and the outer surface (back surface) of the base sheet B1 of the laminate sheet 77 are in contact, and the laminate sheet 77 is at a predetermined temperature and pressure. It is installed so that can be pressed.

  Further, each of the cylindrical rollers 83A and 83B is provided with a rotation mechanism that rotates in a direction according to the moving direction of the laminate sheet 77. Further, the cylindrical rollers 83 </ b> A and 83 </ b> B have such a size that the length between the bottom surfaces is equal to or larger than the width of the laminate sheet 77.

  In the roll press machine 83, the precursor layer 78 on the laminate sheet 77 is heated and pressurized as necessary to become a porous body layer 18A (the porous body layer 18 when used as an anode). Then, the laminate sheet 87 in which the porous body layer 18 </ b> A is formed on the laminate sheet 77 is wound around the core 86 by the rotation of the winding core driving motor.

  Next, as shown in FIG. 17A, the laminate sheet 87 wound around the core 86 is cut into a predetermined size to obtain an electrode sheet ES10. In the case of the electrode sheet ES10 shown in FIG. 17 (a), an edge 12A where the surface of the metal foil sheet 16A is exposed is formed. The edge portion 12A is adjusted so that the electrode forming coating liquid L2 is applied only to the central portion of the metal foil sheet 16A when the electrode forming coating liquid L2 is applied onto the metal foil sheet 16A of the laminate sheet 75. Can be formed.

  Next, as shown in FIG. 17B, the electrode sheet ES10 is punched out in accordance with the scale of the electrochemical device to be manufactured, and the anode 10 shown in FIG. 17C is obtained. At this time, the anode 10 in which the anode lead 12 is integrated in advance can be obtained by punching the electrode sheet ES10 so that the edge portion 12A described above is included as the anode lead 12. When the anode lead conductor 12 and the cathode lead 22 are not connected, the anode lead conductor 12 and the cathode lead 22 are separately prepared and electrically connected to the anode 10 and the cathode 20, respectively. To do.

(Dry method)
Next, the case where the composite particle P10 manufactured through the granulation process described above is used and an electrode is formed by a dry method without using a solvent will be described.

  In this case, the active material-containing layer is formed through the following active material-containing layer forming step. In this active material-containing layer forming step, the powder P12 containing at least the composite particles P10 is subjected to heat treatment and pressure treatment to form a sheet to obtain a sheet 180 containing at least the composite particles, and the sheet 180 is converted into the active material. An active material-containing layer disposing step of disposing on the current collector as the containing layer (active material-containing layer 18 or active material-containing layer 28).

  The dry method is a method of forming an electrode without using a solvent. 1) The solvent is insoluble and safe. 2) Only the particles are rolled without using a solvent, so that the electrode (porous body layer) is densified. 3) Particles made of an electrode active material in the drying process of a liquid film made of an electrode-forming coating solution coated on a current collector, which is a problem in a wet method because no solvent is used There are advantages such as no aggregation and uneven distribution of P1, particles P2 made of a conductive aid for imparting conductivity, and particles P3 made of a binder.

  And this sheeting process can be suitably performed using the hot roll press shown in FIG.

  FIG. 4 is an explanatory view showing an example of a sheet forming process (when using a hot roll press) when manufacturing an electrode by a dry method.

  In this case, as shown in FIG. 18, powder P12 containing at least composite particles P10 is put between a pair of heat rolls 84 and 85 of a heat roll press (not shown), and these are mixed. Kneading and rolling with heat and pressure to form a sheet 180 (active material-containing layer). At this time, the surface temperature of the hot rolls 84 and 85 is preferably 60 to 120 ° C., and the pressure is preferably 20 to 5000 kgf / cm.

  Here, the powder P12 containing at least the composite particles P10 includes at least one of particles P1 made of an electrode active material, particles P2 made of a conductive auxiliary agent for imparting conductivity, and particles P3 made of a binder. The seed particles may be further mixed.

  In addition, the powder P12 containing at least the composite particles P10 may be previously kneaded by a mixing means such as a mill before being put into the hot roll press shown in FIG.

  Next, the sheet 180 (active material-containing layer) and the current collector are brought into electrical contact to produce an electrode sheet ES10 similar to that shown in FIG. Note that the current collector and the sheet 180 (active material-containing layer) may be electrically contacted after the sheet 180 (active material-containing layer) is formed by a hot roll press machine. The active material containing layer (powder P12 containing at least composite particles P10) distributed on one surface of the current collector to the hot roll 84 and the hot roll 85, Sheet formation of the containing layer and electrical connection between the active material containing layer and the current collector may be performed simultaneously.

  Next, by a method similar to the method shown in FIGS. 17A to 17C, the electrode sheet ES10 is punched out in accordance with the scale of the electrochemical device to be manufactured, and the anode 10 (and the cathode 20) is obtained. At this time, the anode 10 in which the anode lead 12 is integrated in advance can be obtained by punching the electrode sheet ES10 so that the edge portion 12A described above is included as the anode lead 12. When the anode lead conductor 12 and the cathode lead 22 are not connected, the anode lead conductor 12 and the cathode lead 22 are separately prepared and electrically connected to the anode 10 and the cathode 20, respectively. To do.

  In the active material containing layer (the active material containing layer 18 or the active material containing layer 28) formed by the wet method and the dry method described above, the internal structure schematically shown in FIG. 19 is formed. That is, in the active material containing layer (the active material containing layer 18 or the active material containing layer 28), the particles P1 made of the electrode active material and the conductive auxiliary agent are used even though the particles P3 made of the binder are used. A structure is formed in which the particles P2 made of are electrically coupled without being isolated.

  Next, the element assembly processing unit 94 assembles an electrochemical element by using the laminate (electrode) of the current collector and the active material-containing layer as at least one of the anode and the cathode, preferably both electrodes. .

  More specifically, first, a separately prepared separator 40 is disposed in contact with the anode 10 and the cathode 20 to complete the element body 60.

  Next, the case 50 is produced. First, when the first film and the second film are composed of the composite packaging film described above, a dry lamination method, a wet lamination method, a hot melt lamination method, and an extrusion lamination method are used. It is produced using a known production method such as Note that this case is preferably manufactured in an inert gas atmosphere, but it is not necessarily performed in an inert gas atmosphere. However, the operation of sealing the element body 60 and the electrolyte solution 30 in the case 50 is performed in an inert gas atmosphere.

  For example, a film that becomes a synthetic resin layer constituting the composite packaging film, and a metal foil made of aluminum or the like are prepared. The metal foil can be prepared, for example, by rolling a metal material.

  Next, a composite packaging film (multilayer film) is preferably obtained by laminating a metal foil via an adhesive on a film that becomes a layer made of a synthetic resin so as to have a configuration of a plurality of layers described above. Is made. Then, the composite packaging film is cut into a predetermined size to prepare one rectangular film.

  Next, as described above with reference to FIG. 2, the single film 53 is folded and the element body 60 is disposed.

  Next, of the contact portions to be heat-sealed between the first film 51 and the second film 52, the edge portion (seal portion 51B) of the first film 51 and the second film 52 to be heat-sealed. A heat-sealing process is performed on a portion where the first lead and the second lead are disposed between the edge portion (seal portion 52B) to be heat-sealed. Here, it is preferable to apply the above-mentioned adhesive to the surface of the anode lead 12 from the viewpoint of obtaining sufficient sealing performance of the case 50 more reliably. Thereby, after the heat fusion treatment, an adhesive layer 14 made of an adhesive that contributes to the adhesion between the anode lead 12 and the first film 51 and the second film 52 is formed. It is formed. Next, in a procedure similar to the procedure described above, a case having a sufficient hermeticity can be obtained by performing the thermal fusion treatment on the portion around the cathode lead 22 simultaneously or separately with the thermal fusion treatment. 50 can be formed.

  Next, of the seal portion 51B (edge portion 51B) of the first film 51 and the seal portion 52B (edge portion 52B) of the second film 51, the portion around the anode lead 12 and the cathode lead 22 described above. A part other than the surrounding part is heat-sealed (heat-welded) by a desired seal width under a predetermined heating condition using, for example, a sealing machine.

  At this time, as shown in FIG. 20, in order to secure the opening H51 for injecting the non-aqueous electrolyte solution 30, a part not to be heat-sealed is provided. As a result, the case 50 having the opening H51 is obtained.

  Then, as shown in FIG. 20, the nonaqueous electrolyte solution 30 is injected from the opening H51 in an inert gas atmosphere. Subsequently, the opening H51 of the case 50 is sealed using a vacuum sealer. Furthermore, as shown in FIG. 21, from the viewpoint of improving the volume energy density based on the volume of the space in which the obtained electrochemical capacitor 1 is to be installed, case 5 lithium ion secondary battery 1 (electric (Chemical element) is completed.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, the electrochemical element formed by the manufacturing method of the present invention may have an electrode formed by the manufacturing method of the present invention as at least one of an anode and a cathode, and the other configurations and structures are as follows. There is no particular limitation.

  For example, in the description of the above embodiment, the case where an electrochemical device including one anode 10 and one cathode 20 is manufactured has been described. However, one or more anodes 10 and one cathode 20 are provided, and the anode 10 and the cathode 20 are provided. An electrochemical element having a configuration in which one separator 40 is always disposed between the two may be manufactured. That is, as shown in FIG. 22, a plurality of unit cells (cells composed of the anode 10, the cathode 20, and the electrolyte layer 40 that also serves as a separator) 102 are stacked and held in a predetermined case 9 in a sealed state ( You may have the structure of the module 200 packaged.

  Furthermore, in this case, the unit cells may be connected in parallel or in series. Further, for example, a battery unit in which a plurality of modules 200 are electrically connected in series or in parallel may be configured. As this battery unit, for example, as in the battery unit 300 shown in FIG. 23, for example, the cathode terminal 104 of one module 200 and the anode terminal 101 of another module 200 are electrically connected by a metal piece 108. Thus, a battery unit 300 connected in series can be configured.

  When the module 200 is manufactured as described above, the element assembly processing unit 94 may be provided with a mechanism for assembling the following elements.

  That is, for example, when the three anodes 10a to 10c, the cathodes 20a to 20c, and the five separators 40a to 40e are stacked, for example, as shown in FIG. A stacked body 60A is formed by sequentially stacking the anodes 10a to 10c, the cathodes 20a to 20c, and the five separators 40a to 40e. Then, the stacked body 60A is sealed in the case 50 in an inert gas atmosphere.

  Further, when the module 200 and the battery unit 300 are configured, a protective circuit (not shown) and a PTC (not shown) similar to those provided in an existing battery are further provided as necessary. Also good.

  In the above description of the embodiment of the electrochemical element, the secondary battery has been described. For example, the electrochemical element of the present invention includes an anode, a cathode, and an electrolyte layer having ion conductivity. As long as the anode and the cathode are arranged to face each other with the electrolyte layer interposed therebetween, and may be a primary battery. As the electrode active material of the composite particle P10, in addition to the above-described exemplary materials, those used in existing primary batteries may be used. The conductive auxiliary agent and the binder may be the same as those exemplified above.

  Furthermore, the electrode of the present invention is not limited to an electrode for a battery. For example, the electrode is used in an electrolytic cell, an electrochemical capacitor (such as an electric double layer capacitor or an aluminum electrolytic capacitor), or an electrochemical sensor. May be. Further, the electrochemical element of the present invention is not limited to a battery, and may be, for example, an electrolytic cell, an electrochemical capacitor (such as an electric double layer capacitor or an aluminum electrolytic capacitor), or an electrochemical sensor. Good. For example, in the case of an electrode for an electric double layer capacitor, a carbon material having a high electric double layer capacity such as coconut shell activated carbon, pitch-based activated carbon, phenol resin-based activated carbon can be used as the electrode active material constituting the composite particle P10. .

  Further, for example, as an anode used for salt electrolysis, for example, a composite particle obtained by thermally decomposing ruthenium oxide (or a composite oxide of ruthenium oxide and other metal oxide) is used as an electrode active material in the present invention. An electrode in which an active material-containing layer containing composite particles P10 obtained is formed on a titanium substrate may be used as a constituent material of P10.

  In addition, when the electrochemical device of the present invention is an electrochemical capacitor, the electrolyte solution is not particularly limited, and a non-aqueous electrolyte solution (an organic solvent is used) used in an electrochemical capacitor such as a known electric double layer capacitor. Non-aqueous electrolyte solution) can be used.

  Furthermore, the type of the non-aqueous electrolyte solution 30 is not particularly limited, but is generally selected in consideration of the solubility of solute, the degree of dissociation, and the viscosity of the solution, and has a high conductivity and a high potential window (a high decomposition start voltage). It is desirable that the non-aqueous electrolyte solution. Examples of the organic solvent include propylene carbonate, diethylene carbonate, and acetonitrile. Examples of the electrolyte include quaternary ammonium salts such as tetraethylammonium tetrafluoroborate (boron tetrafluoride tetraethylammonium). In this case, it is necessary to strictly manage the moisture content.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

(Example 1)
(Production of carbon materials for electrodes)
An electrochemical device manufacturing apparatus having the same configuration as that shown in FIG. 11 was used. Further, a plasma torch having the same configuration as that shown in FIG. Using a plasma torch, mesophase carbon micro beads (spherical artificial graphite, MCMB) were continuously sprayed as carbon powder (carbonaceous material) and subjected to thermal plasma treatment to obtain a carbon material for an electrode. MCMB is spherical artificial graphite.

During the thermal plasma treatment, a plasma gas having the chemical composition shown in Table 1 is used, the pressure in the torch is 53 kPa, the frequency is 2 MHz, the input power is 40 kW, and the powder supply rate is 1.6 g / min. The plasma treatment time was 5 minutes. According to the model calculation, the plasma temperature is 10,000 ° C. or higher. The flow rate ratio when using a mixed gas as the plasma gas was Ar: H ₂ = 93: 7.

(Preparation of composite particles for electrodes)
Manufacture of composite particles for stirred rolling fluidized bed electrodes filled with dry argon gas without contacting the carbon material (MCMB) for surface cleaning and surface modification obtained after thermal plasma treatment. The mixture was transferred to a chamber, and particle composite was performed using acetylene black as a conductive additive and polyvinylidene fluoride as a binder.

  Particle compositing was performed as follows. First, a liquid (raw material liquid) was prepared by dispersing sufficiently dried acetylene black in a solution obtained by dissolving sufficiently dried polyvinylidene fluoride in N, N-dimethylformamide (solvent, water content of 40 ppm or less). Next, this liquid (acetylene black 3% by mass, polyvinylidene fluoride 2% by mass) was sprayed with argon gas onto a powder of carbon material for electrodes (MCMB) which was fluidized with dry argon gas in a container. The solution was allowed to adhere to the powder surface. Note that N, N-dimethylformamide was removed from the surface of the powder almost simultaneously with the spraying by maintaining the temperature in the atmosphere where the powder was placed at the time of spraying at 80 ° C. In this manner, acetylene black and polyvinylidene fluoride were adhered to the powder surface to obtain granulated particles (average particle size: 150 μm).

  The amount of each of the cathode and anode electrode active materials, conductive additives and binders used in the granulation treatment is such that the mass ratio of these components in the finally obtained granulated particles is the electrode active material. (90% by mass), conductive additive (6% by mass) and binder (4% by mass) were adjusted. The obtained granulated particles were transferred to and stored in a sample storage unit of an electrochemical device manufacturing apparatus filled with dry argon gas.

(Production of electrodes)
The electrode was made by a dry method using an electrochemical element manufacturing apparatus filled with dry argon, using a dry method without using a solvent. The granulated particles having an average particle size of 150 μm stored in the sample storage unit of the electrochemical device manufacturing apparatus are transferred to the dry method electrode manufacturing unit without being exposed to the atmosphere, and the hot melt conductive layer is previously formed to a thickness of 3 μm. While being placed on the applied current collector (copper foil, thickness 30 μm), it was processed by a hot roll press so as to have a constant active material density, and an electrode having an electrode active material layer thickness of 70 μm was prepared. The obtained electrode was moved to the sample storage part of the electrochemical device manufacturing apparatus filled with dry argon gas and stored.

(Production of electrochemical device)
The production of the lithium ion secondary battery was performed in the electrochemical device manufacturing section filled with dry argon gas in the electrochemical device manufacturing apparatus. The battery was produced as follows. A negative electrode made of carbon material for electrodes (MCMB) stored in the sample storage part of the electrochemical device manufacturing apparatus, a positive electrode made of lithium cobalt oxide and sufficiently introduced into the electrochemical device manufacturing part after being sufficiently dried, a polypropylene porous film A separator made of was cut into a substantially rectangular shape to obtain a sheet.

Next, the sheets are positioned and laminated in the order of the positive electrode, the porous film, and the negative electrode, and then the laminate obtained by welding the elongated aluminum foil to the positive electrode tab and the elongated nickel foil to the negative electrode tab, respectively, and taking out the leads. The body was put in an aluminum laminate pack, and an appropriate amount of 1 mol / L LiPF ₆ / EC + DMC [EC: DMC = 1: 2 (volume ratio)] electrolytic solution was poured therein to impregnate the laminate. Subsequently, after removing the excess electrolyte solution in the laminate, the aluminum laminate pack was heat sealed to obtain a lithium ion secondary battery.

(Example 2)
The same procedure as in Example 1 except that the plasma treatment atmosphere gas in the step of producing the composite particles for electrodes in the production of the composite particles for electrodes is Ar: H ₂ : CO 2 = 87: 7: 6 It was produced under the conditions.

(Example 3)
It was produced in the same manner as in Example 1 except that spray drying granulation was performed instead of granulation using a stirring and rolling fluidized bed in the step of particle compositing in the production of composite particles for electrodes.

  Particle compositing was performed as follows. First, a solution obtained by dispersing sufficiently dried acetylene black in a solution obtained by dissolving MCMB after thermal plasma treatment and sufficiently dried polyvinylidene fluoride in N, N-dimethylformamide (solvent, moisture 40 ppm or less) ( Raw material liquid) was prepared. Next, this liquid (MCMB 22.5% acetylene black 1.5% by mass, polyvinylidene fluoride 0.5% by mass) was granulated by a spray drying method to obtain granulated particles having an average particle size of 40 μm.

(Example 4)
The same procedure and conditions as in Example 3 except that the plasma treatment atmosphere gas in the step of producing the composite particles for electrodes in the production of the composite particles for electrodes is Ar: H 2: CO 2 = 87: 7: 6 It was produced with.

(Comparative Example 1)
(Production of electrodes)
MCMB is not subjected to surface modification treatment and particle compositing, and in the atmosphere, the negative electrode active material, the conductive additive, the binder, and the composition ratio thereof are the same as in Example 1, and the electrode Was made.

  The electrode was produced as follows. Polyvinylidene fluoride was dissolved in NMP so as to be 5% by mass in N-methyl-2-pyrrolidone (NMP) to prepare a binder solution. These were dry-mixed with a hypermixer such that 90% by mass of the active material and 6% by mass of the conductive material with respect to 4% by mass of polyvinylidene fluoride. The binder solution was added to this mixture so that the active material was 90% by mass and the conductive auxiliary was 6% by mass with 4% by mass of polyvinylidene fluoride, and was dissolved in a hypermixer to obtain an active material mixture paint. . The prepared mixture paint was applied to one side of a current collector (copper foil) with an extrusion nozzle and dried. This was processed with a roller press so as to have a predetermined active material density, cut into a predetermined size, and an electrode having a thickness and an active material density equivalent to those of the example was obtained.

(Production of electrochemical device)
The production of the lithium ion secondary battery was different from the production place, but the environment was the same dry environment as in Example 1. Instead of using the electrochemical device manufacturing unit filled with dry argon gas in the electrochemical device manufacturing apparatus of Example 1, the glove box was filled with dry argon gas.

(Comparative Example 2)
The composite particles for electrodes were prepared in the same manner as in Example 1 except that the surface modification treatment was not performed on the MCMB.

(Comparative Example 3)
Production of the composite particles for electrodes was carried out in the same manner as in Example 1. However, production of electrodes and production of electrochemical elements were carried out in the same manner as in Comparative Example 1.
[Battery charge / discharge characteristics evaluation test]
Evaluation tests were performed on the initial charge / discharge efficiency (initial charge / discharge efficiency), initial discharge capacity, and cycle characteristics of the batteries of Examples 1 to 4 and Comparative Examples 1 to 3.

  Charging / discharging current was 1C, charging was performed by the constant current low voltage method, and discharging was performed by the constant current method. Table 2 shows the results together with examples and comparative examples. The initial charge / discharge efficiency is {(initial discharge capacity) / (initial charge capacity)} × 100, the initial discharge capacity is the capacity when the discharge capacity of Comparative Example 1 is 100, and the cycle characteristics are discharge. A cycle in which the capacity is 80% or less of the initial discharge capacity is shown.

  The composite particles for electrodes and electrodes obtained by the present invention can be used for electrochemical devices, and the electrochemical devices obtained by the present invention are power supplies for backup of power supplies such as portable devices (small electronic devices), hybrid vehicles. Can be used as an auxiliary power source.

It is a front view which shows the basic composition of an example (lithium ion secondary battery) of the electrochemical element manufactured by suitable one Embodiment of the manufacturing method of this invention. FIG. 2 is a development view when the inside of the electrochemical element shown in FIG. 1 is viewed from the normal direction of the surface of an anode 10. It is a schematic cross section at the time of cut | disconnecting the electrochemical element shown in FIG. 1 along the X1-X1 line | wire of FIG. It is a schematic cross section which shows the principal part at the time of cut | disconnecting the electrochemical element shown in FIG. 1 along the X2-X2 line | wire of FIG. It is a schematic cross section which shows the principal part at the time of cut | disconnecting the electrochemical element shown in FIG. 1 along the YY line of FIG. It is a schematic cross section which shows an example of the basic composition of the film used as the constituent material of the case of the electrochemical element shown in FIG. It is a schematic cross section which shows another example of the basic composition of the film used as the constituent material of the case of the electrochemical element shown in FIG. It is a schematic cross section which shows an example of the basic composition of the anode of the electrochemical element shown in FIG. It is a schematic cross section which shows an example of the basic composition of the cathode of the electrochemical element shown in FIG. It is a schematic cross section which shows an example of the basic composition of the composite particle manufactured in the granulation process in the manufacturing method of this invention. It is explanatory drawing which shows the basic composition of suitable one Embodiment of the electrochemical element manufacturing apparatus of this invention. It is a schematic block diagram of the generator (plasma torch) of the high frequency thermal plasma used in order to perform a plasma processing. It is explanatory drawing which shows an example of the granulation process at the time of manufacturing an electrode. It is explanatory drawing which shows an example of the coating liquid preparation process at the time of manufacturing an electrode by a wet method. It is explanatory drawing for demonstrating the formation process of the electrode sheet using the coating liquid for electrode formation. It is explanatory drawing for demonstrating the formation process of the electrode sheet using the coating liquid for electrode formation. (A)-(c) is explanatory drawing for demonstrating the process of forming an electrode from an electrode sheet. It is explanatory drawing which shows an example of the sheeting process at the time of manufacturing an electrode by a dry process. It is a schematic cross section which shows roughly the internal structure in the active material content layer of the electrode manufactured by this invention. It is explanatory drawing which shows an example of the procedure at the time of filling a nonaqueous electrolyte solution in a case. It is a perspective view which shows the electrochemical capacitor at the time of bending the seal part of a case. It is a schematic cross section which shows the basic composition of the other form of the electrochemical element obtained by the manufacturing method of the electrochemical element of this invention. It is a schematic cross section which shows the basic composition of another one Embodiment of the electrochemical element of this invention. It is explanatory drawing which shows the manufacturing method in the case of forming the electrochemical element which consists of a laminated body comprised by the some electrode and separator. It is a schematic cross section which shows roughly the internal structure in the active material content layer of the electrode formed using the partial structure of the conventional composite particle for electrodes, and the conventional composite particle for electrodes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrochemical element (lithium ion secondary battery), 5 ... Fluid tank, 6 ... Raw material liquid droplet, 10 ... Anode, 12 ... Anode lead, 14 ... Insulator, 20 ... Cathode, 22 ... Lead for cathode, 24 ... Insulator, 22 ... Active material containing layer, 24 ... Current collector, 30 ... Nonaqueous electrolyte solution, 32 ... Active material containing layer, 34 ... Current collector, 40 ... Electrolyte Layer, 50 ... case, 52 ... opening, 54 ... opening, 60 ... element, 84,85 ... heat roll, 90 ... electrochemical element manufacturing apparatus, 91 ... plasma treatment , 92... Granulation processing unit, 93... Active material containing layer formation processing unit, 94... Element assembly processing unit, 95... Inert gas atmosphere forming means (glove box), 100. -High frequency thermal plasma generator (plasma torch), 110 ... water-cooled double tube, DESCRIPTION OF SYMBOLS 20 ... High frequency coil, 130 ... Cover, 140 ... Water-cooled probe for supplying powder (particles made of electrode active material), 150 ... Chamber, 180 ... Sheet (active material-containing layer), 200 ... Module , 300 ... battery unit, L2 ... electrode-forming coating solution, P1 ... particles made of electrode active material, P2 ... particles made of conductive assistant, P3 ... particles made of binder. , P10 ... composite particles, P12 ... powder containing composite particles P10.

Claims (21)

In a plasma gas atmosphere, a plasma treatment step of obtaining particles made of an electrode active material having electron conductivity by subjecting a raw material made of a carbonaceous material to high frequency thermal plasma treatment;
The particles made of the electrode active material obtained after the plasma treatment step are integrated by closely adhering a conductive additive and a binder capable of binding the electrode active material and the conductive additive. A granulating step of forming composite particles for an electrode comprising the electrode active material, the conductive auxiliary agent, and the binder;
Have
Performing the granulation step in an inert gas atmosphere;
A method for producing composite particles for an electrode. The method for producing composite particles for an electrode according to claim 1, wherein the granulating step is performed based on a spray drying method. The granulation step includes
A raw material liquid preparation step of preparing a raw material liquid containing the binder, the conductive additive and a solvent;
A fluidized bed forming step of introducing particles made of the electrode active material into a fluidized tank and fluidizing the particles made of the electrode active material;
By spraying the raw material liquid into the fluidized bed containing the particles made of the electrode active material, the raw material liquid is attached to the particles made of the electrode active material and dried, so that the surface of the particles made of the electrode active material A spray drying step of removing the solvent from the adhering raw material liquid, and causing the particles made of the electrode active material and the particles made of the conductive additive to be in close contact with the binder;
Including
The manufacturing method of the composite particle for electrodes of Claim 1 characterized by these. In the fluidized bed forming step, an air stream is generated in the fluidized tank, particles made of the electrode active material are introduced into the air stream, and the particles made of the electrode active material are fluidized bed.
The method for producing composite particles for an electrode according to claim 3 . In the granulation step, the temperature in the fluidized tank is adjusted to 50 ° C. or more and below the melting point of the binder,
The method for producing composite particles for an electrode according to claim 3 or 4. In the granulation step, the air flow generated in the fluidized tank is an air flow made of an inert gas,
The method for producing composite particles for an electrode according to any one of claims 3 to 5, wherein: The solvent contained in the raw material liquid can dissolve or disperse the binder and can disperse the conductive aid;
The method for producing composite particles for an electrode according to any one of claims 3 to 6, wherein: The method for producing composite particles for an electrode according to claim 7, wherein a ratio of moisture in the solvent contained in the raw material liquid is 100 ppm or less. The electrode according to any one of claims 1 to 8, wherein the electrode active material is an active material that can be used for at least one of a cathode and an anode of a primary battery or a secondary battery. For producing composite particles for use. Composite particle for electrode according to any one of claims 1-8, wherein the electrode active material is carbon materials having electron conductivity can be used in electrodes of the electrochemical capacitor Manufacturing method. The particle | grain preservation | save process of sealing in the case which can be preserve | saved in the state sealed in the said inert gas atmosphere is further included after the said granulation process, The composite particle for electrodes obtained further is characterized by the above-mentioned. The manufacturing method of the composite particle for electrodes any one of these. A method for producing an electrode having at least a conductive active material-containing layer containing an electrode active material, and a conductive current collector disposed in electrical contact with the active material-containing layer,
A composite particle forming step of forming composite particles for electrodes by the method for producing composite particles for electrodes according to any one of claims 1 to 11,
An active material-containing layer forming step of forming the active material-containing layer using the composite particles at a site where the active material-containing layer of the current collector is to be formed;
Have
Performing the active material containing layer forming step after the plasma treatment step of the composite particle forming step in an inert gas atmosphere,
An electrode manufacturing method characterized by the above. The active material-containing layer forming step includes
A sheet forming step of obtaining a sheet containing at least the composite particles by subjecting the powder containing at least the composite particles to heat treatment and pressure treatment to form a sheet;
An active material-containing layer arrangement step of arranging the sheet as the active material-containing layer on the current collector;
Having
The method for producing an electrode according to claim 12. The active material-containing layer forming step includes
A coating liquid preparation step of preparing a coating liquid for electrode formation by adding the composite particles to a liquid capable of dispersing or kneading the composite particles;
Applying the electrode-forming coating liquid to a portion of the current collector where the active material-containing layer is to be formed;
Solidifying a liquid film composed of the electrode-forming coating liquid applied to a portion of the current collector where the active material-containing layer is to be formed,
The method for producing an electrode according to claim 12. The electrode preservation | save process of sealing further in the case which can be preserve | saved in the state sealed in the said inert gas atmosphere after the said active material content layer formation process is further included, It is characterized by the above-mentioned. The manufacturing method of the electrode of any one of these. A method for producing an electrochemical element comprising at least an anode, a cathode, and an electrolyte layer having ionic conductivity, wherein the anode and the cathode are arranged to face each other with the electrolyte layer interposed therebetween,
An electrode forming step of forming an electrode by at least one of the anode and the cathode by the electrode manufacturing method according to any one of claims 12 to 14,
Producing the electrode obtained by the electrode forming step in an inert gas atmosphere;
The manufacturing method of the electrochemical element characterized by these. A plasma processing unit that performs plasma processing to obtain particles made of an electrode active material having electron conductivity by performing high-frequency thermal plasma processing on a raw material made of a carbonaceous material in a plasma gas atmosphere;
A conductive assistant and a binder capable of binding the electrode active material and the conductive assistant to particles made of the electrode active material obtained after the plasma treatment in an inert gas atmosphere; A granulation treatment unit that performs a granulation treatment to form composite particles for an electrode including the electrode active material, the conductive auxiliary agent, and the binder,
An inert gas atmosphere forming means for performing the granulation treatment in an inert gas atmosphere;
Having
An apparatus for producing composite particles for electrodes. After the granulation treatment, further comprising a particle preservation treatment section for carrying out a particle preservation treatment for sealing the obtained composite particles for an electrode in a case that can be preserved in a sealed state in the inert gas atmosphere. The composite particle manufacturing apparatus for an electrode according to claim 17, Electrode manufacturing apparatus for manufacturing an electrode having at least a conductive active material-containing layer containing an electrode active material, and a conductive current collector arranged in electrical contact with the active material-containing layer Because
A plasma processing unit that performs plasma processing to obtain particles made of an electrode active material having electron conductivity by performing high-frequency thermal plasma processing on a raw material made of a carbonaceous material in a plasma gas atmosphere;
A conductive assistant and a binder capable of binding the electrode active material and the conductive assistant to particles made of the electrode active material obtained after the plasma treatment in an inert gas atmosphere; A granulation treatment unit that performs a granulation treatment to form composite particles for an electrode including the electrode active material, the conductive auxiliary agent, and the binder,
An active material-containing layer forming treatment unit that forms the active material-containing layer using the composite particles at a site where the active material-containing layer of the current collector is to be formed;
An inert gas atmosphere forming means for performing the treatment in the granulation treatment section and the treatment in the active material-containing layer formation treatment section in an inert gas atmosphere;
Having
An electrode manufacturing apparatus. After the active material-containing layer is formed in the active material-containing layer formation processing section, an electrode storage treatment is performed in which the obtained electrode is sealed in a case that can be stored in a sealed state in the inert gas atmosphere. The electrode manufacturing apparatus according to claim 19, further comprising a section. An anode, a cathode, and an electrolyte layer having ion conductivity, wherein the anode and the cathode are arranged to face each other with the electrolyte layer interposed therebetween, and the anode and the cathode are An electrochemical device having a configuration including at least a conductive active material-containing layer containing an electrode active material and a conductive current collector disposed in electrical contact with the active material-containing layer is manufactured. An electrochemical device manufacturing apparatus for
A plasma processing unit that performs plasma processing to obtain particles made of an electrode active material having electron conductivity by performing high-frequency thermal plasma processing on a raw material made of a carbonaceous material in a plasma gas atmosphere;
A conductive assistant and a binder capable of binding the electrode active material and the conductive assistant to particles made of the electrode active material obtained after the plasma treatment in an inert gas atmosphere; A granulation treatment unit that performs a granulation treatment to form composite particles for an electrode including the electrode active material, the conductive auxiliary agent, and the binder,
An active material-containing layer forming treatment unit that forms the active material-containing layer using the composite particles at a site where the active material-containing layer of the current collector is to be formed;
An element assembly processing unit for assembling the electrochemical element by using a laminate of the current collector and the active material-containing layer as an electrode of at least one of the anode and the cathode;
An inert gas atmosphere forming means for performing the processing in the granulation processing section, the processing in the active material-containing layer formation processing section, and the processing in the element assembly processing section in an inert gas atmosphere;
Having
An electrochemical element manufacturing apparatus characterized by the above.

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