WO2014141547A1

WO2014141547A1 - Device and method for producing lithium ion secondary battery

Info

Publication number: WO2014141547A1
Application number: PCT/JP2013/082324
Authority: WO
Inventors: 千恵美窪田; 昌作石原; 菊池　廣; 高原　洋一; 正志西亀
Original assignee: 株式会社日立製作所
Priority date: 2013-03-13
Filing date: 2013-12-02
Publication date: 2014-09-18
Also published as: KR101697249B1; CN104871360A; JP2014179170A; KR20150081301A; JP6033131B2

Abstract

Provided is a device for producing a lithium ion secondary battery that comprises at least: a coating unit that applies an electrode material slurry containing an active material for a positive electrode or a negative electrode, a binder, a solidification agent, and a first solvent to the surface of a current collector foil (15); a solidification chamber (18) that brings a solidification liquid (24) into contact with the coating film (22) that has been applied to the surface of the current collector foil (15) and solidifies the coating film (22); and a drying chamber that removes a liquid component contained in the coating film (22) that has solidified in the solidification chamber (18) and dries the coating film (22). The solidification chamber (18) is provided with a spray nozzle (23) that sets the contact width of the solidification liquid (24) along a direction that is orthogonal to the conveyance direction of the current collector foil (15) to be greater than the width of the coating film (22) that is applied to the surface of the current collector foil (15) and within a current collector tab attachment position of the current collector foil (15).

Description

Lithium ion secondary battery manufacturing apparatus and manufacturing method

The present invention relates to a technique for manufacturing a lithium ion secondary battery, and more particularly to a technique effective when applied to the manufacture of an electrode plate of a lithium ion secondary battery.

As a background art in the technical field of the present invention, there is Japanese Patent No. 3539911 (Patent Document 1). This publication states that “a method for producing a coating sheet coated with at least an active material, a binder and a solvent, wherein the coating film is at a temperature below the boiling point of the solvent contained in the coating. Heating the coating sheet at a temperature lower than the temperature below the boiling point of the solvent so as to maintain a uniform state of the first step of heating the sheet and the distribution of the binder in the coating film. A second step of heating and a third step of heating the coating sheet at a temperature equal to or higher than the temperature lower than the boiling point of the solvent. Through the third step, the coating sheet is the second step. It is described as “a method for producing a coating film sheet in which a state in which the distribution of the binder in the coating film is made uniform by the process is maintained” is described.

Japanese Patent No. 3953911

With the development of portable electronic devices, small secondary batteries that can be repeatedly charged are used as power supply sources for these portable electronic devices. Among them, lithium ion secondary batteries have the advantages of high energy density, long cycle life, low self-discharge characteristics, and high operating voltage, so that they can be used in digital cameras, notebook personal computers, mobile phones, etc. Widely used in portable electronic devices.

Furthermore, in recent years, research and development of large-sized lithium ion secondary batteries capable of realizing high capacity, high output, and high energy density as electric vehicle batteries and power storage batteries have been promoted. In particular, in the automobile industry, in order to cope with environmental problems, the development of an electric vehicle that uses a motor as a power source and a hybrid vehicle that uses both an engine (internal combustion engine) and a motor as power sources are being developed. Yes. Lithium ion secondary batteries are also attracting attention as power sources for such electric vehicles and hybrid vehicles. Furthermore, lithium ion secondary batteries are also becoming increasingly important for applications such as solar power generation and power storage for effective use of nighttime power.

In the lithium ion secondary battery, the positive electrode plate and the negative electrode plate are wound or laminated via a separator that prevents contact between both electrode plates. And after accommodating this winding body or laminated body in a battery exterior container, electrolyte solution is inject | poured in a battery exterior container.

The above-described positive and negative electrode plates are generally manufactured by the following method. First, an electrode slurry is prepared by kneading an active material capable of releasing and occluding lithium ions by charge / discharge and a conductive additive powder with a binder, a solvent, etc., and this slurry is applied using a coating means such as a die coater. Apply thinly and evenly on the metal foil that is the current collector foil. Thereafter, the solvent contained in the slurry on the metal foil (hereinafter, the coating slurry before drying is referred to as a coating film) is dried to form an electrode film and manufacture an electrode plate.

As described above, in the production of a lithium ion secondary battery, an electrode is manufactured through a series of steps including production of a slurry-like electrode material, application of the electrode material to a current collector foil and drying, or a combination of these steps. It is necessary to manufacture a board. However, since the production of such an electrode plate requires a considerable economic burden, the improvement is desired, and the maintenance and management of the quality of the electrode plate is also desired.

In particular, in the process of drying the coating film of the electrode material, in order to produce a high-quality electrode plate and to ensure safety during production, it is common to spend considerable time and cost for drying. is there. That is, in the coating film drying process, the drying proceeds by evaporation of the solvent from the surface of the coating film accompanying the supply of heat to the coating film. However, if the solvent evaporation rate at this time is too high, it becomes well known that uniform drying cannot be performed within the coating film surface, and that the composition in the thickness direction of the electrode material is non-uniform and unstable. In some cases, a large burden is generated on the manufacturing equipment due to restrictions on the drying process.

Therefore, in order to solve the above problems, Patent Document 1 proposes a method of dividing the drying process into a plurality of processes having different application temperatures. However, since this method includes a drying step at a low temperature, the drying rate of the electrode cannot be increased, and the productivity is lowered. Furthermore, it is not easy to make the binder concentration distribution uniform by drying by evaporation of the solvent from the surface of the coating film.

In view of the above problems, the present invention maintains / improves the quality of an electrode plate by manufacturing an electrode plate in which the binder is almost uniformly distributed in the electrode film at a low cost while improving productivity. It is an object of the present invention to provide a manufacturing method and a manufacturing apparatus capable of performing the above, and a lithium ion secondary battery using the electrode plate.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above problems.
At least a coating portion for applying a slurry-like electrode material containing a positive or negative active material, a binder, a solidifying agent, and a first solvent to the surface of the current collector foil, and the surface of the current collector foil. By bringing a solidified liquid into contact with the slurry-like electrode material, a solidification chamber for solidifying the slurry-like electrode material, and a liquid component contained in the electrode material solidified in the solidification chamber are removed, and the electrode material is removed. A drying chamber for drying,
The solidification chamber has a contact width of the solidified liquid along a direction orthogonal to a conveying direction of the current collector foil, which is equal to or greater than a width of the slurry-like electrode material applied to the surface of the current collector foil. It is a manufacturing apparatus of a lithium ion secondary battery provided with the solidification liquid contact mechanism prescribed | regulated within the current collection tab attachment position of foil.

Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

High quality lithium ion secondary batteries can be manufactured at low cost while improving productivity.

It is a whole lineblock diagram showing the single-sided application type electrode board manufacturing device in an embodiment. 1 is a schematic cross-sectional view showing a solidification chamber of an electrode plate manufacturing apparatus in Example 1. FIG. FIG. 3 is a plan view of a main part of a current collector foil showing a spray pattern of a solidified liquid in Example 1. 3 is a graph showing a flow rate distribution of a solidified liquid in Example 1. It is a schematic sectional drawing which shows the solidification chamber of the electrode plate manufacturing apparatus in Example 2. (A) is a top view of the spray mask provided in the solidification chamber of the electrode plate manufacturing apparatus in Example 2, (b) is a sectional view of the spray mask. (A) is a top view of the spray mask provided in the solidification chamber of the electrode plate manufacturing apparatus in Example 3, (b) is a sectional view of the spray mask. It is a schematic sectional drawing which shows the solidification chamber of a double-side coating batch drying type electrode plate manufacturing apparatus. It is a whole block diagram which shows the conventional single-side coating type electrode plate manufacturing apparatus. It is a whole block diagram which shows the conventional sequential double coated electrode plate manufacturing apparatus. It is a whole block diagram which shows the conventional double-side coating batch drying type | mold manufacturing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted. In the embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary. Furthermore, in the drawings for describing the embodiments, hatching may be applied even in a plan view or hatching may be omitted even in a cross-sectional view for easy understanding of the configuration.

First, a conventional general electrode plate manufacturing apparatus for a lithium ion secondary battery will be described with reference to FIGS.

The electrode material used to form the electrode film constituting the positive electrode or negative electrode of a lithium ion secondary battery is composed of an active material capable of releasing and occluding lithium ions by charging and discharging, and a conductive auxiliary powder. It is a high-viscosity slurry liquid that is kneaded and dispersed with a binder, a solvent, and the like.

First, as shown in FIG. 9, the slurry-like electrode described above is applied to the surface of the current collector foil 55 supplied from the current collector foil roll 53 using a coating means 52 such as a die coater installed in the coating unit 51. Apply the material thinly and evenly. Subsequently, the current collector foil 55 coated with the slurry-like electrode material (coating film) is dried by a roller transport system 54 for transporting the current collector foil 55 at a constant speed while being in contact with the back surface of the current collector foil 55. Send to a hot air drying oven shown as 56. In the drying chamber 56, the solvent component contained in the coating film is heated and evaporated to dry the electrode material, and the electrode film is formed on the surface of the current collector foil 55. Thereafter, the current collector foil 55 is wound around the electrode roll 57 and conveyed to the next step. In a normal electrode plate manufacturing process, such a process is separately performed on the front surface and the back surface of the current collector foil 55 to manufacture an electrode plate having electrode films formed on both surfaces of the current collector foil 55.

In order to manufacture high quality electrode plates using the above-mentioned single-side coated electrode plate manufacturing equipment and to ensure safety during manufacturing, it takes considerable time and cost to dry the coating film. Is common. That is, in the coating film drying process, the drying proceeds by evaporation of the solvent from the surface of the coating film accompanying the supply of heat to the coating film. At that time, if the evaporation rate of the solvent is too high, This is because uniform drying becomes impossible or the composition of the electrode material along the thickness direction of the coating film becomes non-uniform and unstable.

In addition, the conveying speed of the current collector foil in the drying process of the manufacturing apparatus is about 1 to 100 m / min, and the observation speed is about 1 to 100 minutes. In a region close to the lower limit of the transport speed, the transport speed in the drying chamber is slow, so that drying at a relatively low temperature with a reduced evaporation rate of the solvent becomes possible. Therefore, it is possible to cope with even a small drying room, and the quality of the electrode plate to be manufactured is easily stabilized.

However, in the region close to the lower limit of the conveyance speed as described above, the productivity of electrode plate production is low, which makes the process relatively expensive and supplies economically inexpensive lithium ion secondary batteries to the market. In some cases, it was an obstacle to do this.

On the other hand, in the region close to the upper limit of the conveyance speed, it is possible to increase the productivity of electrode plate manufacturing, but when trying to secure the drying time necessary to ensure the quality of the electrode plate, the drying chamber is very It becomes long. Therefore, in this case, there is a problem that not only the equipment cost of the drying chamber itself increases, but also a large amount of heat energy for operating the large drying chamber is required, and the running cost increases.

Also, a method of abruptly drying the solvent at a high temperature may be considered in order to increase the productivity of the electrode plate and reduce the equipment cost and running cost by reducing the size of the drying chamber. However, in such a method, the surface of the coating film is dried first, and the composition of the electrode material varies between the inside and the surface of the coating film, or cracks occur on the surface of the coating film. .

In response to these conflicting issues, the electrode plate manufacturing process and equipment are generally constructed by adjusting the two in the middle of both extremes and empirically obtaining the optimum value. Therefore, it has been required to realize an electrode plate manufacturing method that can be applied and dried at high speed and can stabilize the quality of the electrode plate.

FIG. 10 shows a conventional sequential double-side coated electrode plate manufacturing apparatus. Using the coating means 52A such as a die coater installed in the coating section 51A, the above-described slurry-like electrode material is thinly and uniformly applied to the surface of the current collector foil 55 supplied from the current collector foil roll 53. . Subsequently, a hot-air drying furnace showing a current collecting foil 55 coated with a slurry-like electrode material as a drying chamber 56A by a roller conveying system 54A that conveys the current collecting foil 55 at a constant speed while being in contact with the back surface of the current collecting foil 55. Send to. In the drying chamber 56 </ b> A, the solvent component contained in the coating film is heated and evaporated to dry and solidify the electrode material, and the electrode film is formed on the surface of the current collector foil 55. A series of steps so far are the same as the example of FIG.

In the sequential double-sided electrode plate manufacturing apparatus shown in FIG. 10, as in the example of FIG. 9, the current collector foil 55 on which the electrode film is formed is conveyed to the next coating unit 51 </ b> B without being wound around the electrode roll 57, The slurry-like electrode material is thinly and uniformly applied to the back surface of the current collector foil 55 using the coating means 52B. Subsequently, the current collector foil 55 is sent to the next hot air drying furnace shown as the drying chamber 56B by the roller transport system 54B that transports the current collector foil 55 at a constant speed while being in contact with the surface of the current collector foil 55. In the drying chamber 56 </ b> B, the solvent component contained in the coating film applied to the back surface of the current collector foil 55 is heated and evaporated to dry and solidify the electrode material, and an electrode film is formed on the back surface of the current collector foil 55. Thereby, an electrode plate having electrode films formed on both surfaces of the current collector foil 55 is manufactured. Thereafter, the current collector foil 55 is wound around the electrode roll 57 and conveyed to the next step.

In the case of such double-sided continuous coating, although an electrode plate having electrode films formed on both sides of the current collector foil can be produced, a separate drying chamber is required for each coating. There are problems such as an increase in size and an increase in manufacturing cost of the electrode plate.

FIG. 11 shows a double-sided coating batch drying type manufacturing apparatus proposed for solving the above-mentioned problems. A first coating means 52A for applying a slurry-like electrode material to the surface of the current collector foil 55 and a second electrode for applying a slurry-like electrode material to the back surface of the current collector foil 55 are applied to the coating unit 51 of this manufacturing apparatus. Coating means 52B. In this manufacturing apparatus, the electrode material is thinly and uniformly applied to the front surface and the back surface of the current collector foil 55 supplied from the current collector foil roll 53 using the two coating means 52A and 52B. Subsequently, the solvent component in the coating film is heated and evaporated in a hot-air drying furnace shown as the drying chamber 56 to dry and solidify the electrode material, thereby forming an electrode film. By such a method, the current collector foil 55 having electrode films formed on both sides is wound around the electrode roll 57 and conveyed to the next step.

In the case of such double-sided continuous coating, it becomes possible to simultaneously dry the coating film of the electrode material applied on both sides of the current collector foil 55 within one drying chamber 56, so that FIG. Compared to manufacturing equipment, the drying equipment can be halved in principle, and equipment costs and running costs can be reduced.

However, in this method, it is difficult in principle to use a contact-type and inexpensive roller transport system as shown in FIG. 9 or FIG. 10, so which current collector foil is coated with a slurry-like electrode material on both sides. Thus, it becomes a big subject whether it conveys to a drying chamber. Therefore, in the manufacturing apparatus of FIG. 11, a non-contact type conveyance system 58 such as an air levitation conveyance system is employed. However, such a non-contact type transport system is relatively expensive, and problems such as difficulty in controlling the transport remain.

As described above, in the conventional manufacturing method, the slurry-like electrode material coated on the current collector foil is directly introduced into the drying chamber and dried.

On the other hand, the manufacturing method according to the present embodiment includes a solidification step of solidifying the slurry-like electrode material before conveying it to the drying step. By providing this solidification step, various problems caused by drying the slurry-like electrode material as it is in the drying step can be solved simultaneously.

Hereinafter, a manufacturing apparatus and a manufacturing method of a lithium ion secondary battery according to the present embodiment will be described with reference to FIG. FIG. 1 is an overall configuration diagram showing a single-side coating type electrode plate manufacturing apparatus according to the present embodiment.

In the manufacturing process of the lithium ion secondary battery in the present embodiment, first, an electrode material for forming the positive electrode or the negative electrode of the lithium ion secondary battery is prepared, and this electrode material is used in the electrode plate manufacturing apparatus shown in FIG. The coating means 12 such as a die coater installed in the coating unit 11 is filled.

The electrode material in the present embodiment includes at least a positive electrode or negative electrode active material powder capable of releasing and occluding lithium ions by charging and discharging, and optionally a conductive agent powder, and further between the powder components or powder after drying. A binder for binding between the component and the current collector foil, and a solidifying agent according to the present embodiment. These components are formed into a high-viscosity slurry using the first solvent according to the present embodiment. It is prepared as an electrode material. Moreover, it is more preferable to use a binder component as a solidifying agent in the present embodiment.

Next, the above-described high-viscosity slurry-like electrode material is thinly and uniformly applied to the surface of the current collector foil 15 supplied from the current collector foil roll 13 using the coating means 12 installed in the coating unit 11. To do. This process is referred to as a coating process.

Subsequently, the current collector foil 15 is introduced into the solidification chamber 18 by the roller transport system 14 that transports the current collector foil 15 at a constant speed while being in contact with the back surface of the current collector foil 15 coated with the electrode material. The coating film is solidified by bringing the solidified liquid that is the second solvent in the form of the above into contact with the surface of the coating film.

Unlike the first solvent used for preparing the electrode material, the solidified liquid that is the second solvent of the present embodiment has the property that the solidifying agent contained in the electrode material is insoluble, and the first solvent It is necessary to have the property of mutual dissolution.

When the second solvent comes into contact with the surface of the coating film, the second solvent penetrates into the coating film while being mutually dissolved with the first solvent in the coating film. When the concentration of the second solvent increases in the coating film, the solubility of the solidifying agent decreases, so that the solidifying agent precipitates in the coating film, and the precipitated solidifying agent and active material particles contained in the coating film, etc. And the whole coating film is solidified. This process is referred to as a solidification process. Normally, this solidification process is much shorter than the time required for drying, etc., so various components in the coating film are instantaneously fixed, and their concentration distribution and composition fluctuations may occur. Absent.

As described above, in the solidification chamber 18, a solidification step is performed in which the solidified liquid as the second solvent is brought into contact with the surface of the coating film, and the coating film is solidified. There is a concern that the components in the electrode material may flow out to the non-coated portion of the surface 15. A current collecting tab for charging and outputting electricity from the electrode plate is attached to the electrode plate of a normal lithium ion secondary battery, so an electrode film is not formed on the entire surface of the current collecting foil, and both ends in the width direction. The part is exposed. Therefore, also in the present embodiment, in the coating process, the electrode material is not applied to the entire surface of the current collector foil, and both ends in the width direction are left uncoated. If the electrode material adheres to this non-coated part, more specifically, the current collector tab mounting position, the current collector tab attachment failure and the resistance between the current collector foil and current collector tab will increase. There is a risk that the characteristics of

In the solidification process of the present embodiment, in order to make the both ends in the width direction of the current collector foil uncoated, a spray nozzle (not shown in FIG. 1) for spraying the solidified liquid onto the surface of the coating film is provided in the solidification chamber 18. It is provided inside. In the contact method of the solidified liquid using the spray nozzle, the position and amount of spraying can be controlled by the form of the spray nozzle, so the solidified liquid is contacted to the coating film without exceeding the mounting position of the current collecting tab. Can be made.

In the present embodiment, following the solidification step in the solidification chamber 18 described above, the current collector foil 15 holding the solidified coating film is carried into the drying chamber 16 by the roller conveyance system 14. Then, the electrode component of the lithium ion secondary battery is formed by heating and evaporating the solvent component in the coating film to dry the electrode material and forming an electrode film on the surface of the current collector foil 15 by a known method such as hot air drying. Manufacture a board. This process is referred to as a drying process. Thereafter, the current collector foil 15 is wound around the electrode roll 17 and conveyed to the next step.

Thus, in this Embodiment, in order to solidify a coating film prior to the drying process of a coating film, the current collection foil 15 is conveyed using the contact-type roller conveyance system 14 which contacts the current collection foil 15. be able to. That is, in this embodiment, since it is not necessary to use a complicated and expensive non-contact type conveyance system, an inexpensive drying chamber 16 using a contact type roller conveyance system 14 is employed. This advantage is particularly high when the electrode materials applied on both surfaces of the current collector foil 15 are dried together, but of course does not exclude the use of a non-contact type transport system.

Further, in the drying process of the present embodiment, the liquid coating film is not dried, but the coating film solidified in the solidification chamber 18 may be dried. Rapid drying is possible in a short time while preventing fluctuations and fluctuations in the thickness of the coating film.

Due to the characteristics of this embodiment, even when the drying chamber 16 with a short conveying path is used or when a conveying system with a high conveying speed is used, the drying equipment can be downsized without reducing the quality of the electrode film. Can be realized. That is, the drying chamber 16 of the present embodiment shown in FIG. 1 has a structure such as a hot-air drying furnace similar to the conventional drying chamber shown in FIGS. 9 to 11, but has a structure in the drying chamber as compared with the conventional drying chamber. The conveyance path can be shortened.

Hereinafter, the composition of the electrode material used for forming the electrode film of the lithium ion battery in the present embodiment will be described.

As an active material of the positive electrode used in the present embodiment, lithium cobaltate, lithium-containing composite oxide having a spinel structure containing manganese, composite oxide containing nickel, cobalt, manganese, or olivine-type iron phosphate Olivine type compounds represented by the above, but are not limited thereto. In particular, a spinel-structured lithium-containing composite oxide containing manganese is excellent in thermal stability, and thus a highly safe battery can be manufactured.

As the positive electrode active material, only the above-mentioned spinel-structured lithium-containing composite oxide containing manganese may be used, but it may be used in combination with other positive electrode active materials. As such a positive electrode active material, for example, olivine type represented by Li _{1 + x} MO ₂ (−0.1 <x <0.1, M: Co, Ni, Mn, Al, Mg, Zr, Ti, etc.) Compounds and the like. As specific examples of the lithium-containing transition metal oxide having a layered structure, LiCoO ₂ and LiNi _1-x Co _xy Al _y O ₂ (0.1 ≦ x ≦ 0.3, 0.01 ≦ y ≦ 0. 2) and other oxides containing at least Co, Ni and Mn (LiMn _1/3 Ni _1/3 Co _1/3 O ₂ , LiMn _5/12 Ni _5/12 Co _1/6 O ₂ , LiNi _{3 / 5} Mn _1/5 Co _1/5 O ₂ etc.).

Examples of the active material for the negative electrode used in the present embodiment include graphite materials such as natural graphite (flaky graphite), artificial graphite, and expanded graphite, graphitizable carbonaceous materials such as coke obtained by firing pitch, Examples thereof include carbon materials such as non-graphitizable carbonaceous materials such as amorphous carbon obtained by low-temperature firing of furyl alcohol resin (PFA), polyparaphenylene (PPP), and phenol resin. In addition to the carbon material, lithium or a lithium-containing compound can also be used as the negative electrode active material. Examples of the lithium-containing compound include lithium alloys such as Li—Al, and alloys containing elements that can be alloyed with lithium, such as Si and Sn. Furthermore, an oxide-based material such as Sn oxide or Si oxide can be used.

The conduction aid used in the present embodiment is usually used as an electron conduction aid to be contained in the positive electrode film, for example, carbon black, acetylene black, ketjen black, graphite, carbon fiber, carbon nanotube, etc. The carbon material is preferable. Among these carbon materials, acetylene black or ketjen black is particularly preferable from the viewpoint of the amount of addition and conductivity, and the productivity of the coating electrode material slurry. Such a conductive additive may be contained in the negative electrode film, or may be preferably contained in the negative electrode film.

The binder used in this embodiment preferably contains a binder for binding the active material and the conductive additive. As such a binder, for example, a polyvinylidene fluoride polymer (a polymer of a fluorine-containing monomer group containing 80% by mass or more of vinylidene fluoride as a main component monomer), a rubber polymer, or the like is preferably used. Two or more of these polymers may be used in combination. Further, the binder used in the present embodiment is preferably provided in the form of a solution dissolved in a solvent.

Examples of the fluorine-containing monomer group for synthesizing the polyvinylidene fluoride-based polymer include vinylidene fluoride, a mixture of vinylidene fluoride and other monomers, and a monomer mixture containing 80% by mass or more of vinylidene fluoride. It is done. Examples of the other monomer include vinyl fluoride, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether. Examples of the rubber polymer include styrene butadiene rubber (SBR), ethylene propylene diene rubber, and fluorine rubber.

The binder used in the present embodiment may be added separately from the component having the performance as a solidifying agent, or the binder itself may have a function as a solidifying agent. When the binder is added separately from the component having the performance as a solidifying agent, the above-mentioned polymer material having the property of binding the active material and the conductive assistant is preferably used as the binder, but it is not necessarily in the form of a solution dissolved in a solvent. However, it may be in the form of an emulsion in which a polymer material is dispersed in a solvent.

The content of the binder in the electrode material is 0.1% by mass or more, more preferably 0.3% by mass or more and 10% by mass or less, more preferably 5%, based on the dried electrode film. It is desirable that it is less than mass%. If the binder content is too low, not only will the coating film solidify in the solidification process, but the mechanical strength of the electrode film obtained after drying will be insufficient, causing the electrode film to peel from the current collector foil. There is. On the other hand, if the binder content is too large, the amount of the active material in the electrode film decreases, and the battery capacity may be lowered.

The current collector foil used in the present embodiment is not limited to a sheet-like foil, and a pure metal or alloy conductive material such as aluminum, copper, stainless steel, titanium, etc. is used as its base, and a net, punch Metal foil, foam metal, foil processed into a plate shape, or the like can also be used. The thickness of the substrate is, for example, 5 μm to 30 μm, more preferably 8 μm to 16 μm.

Examples of the method for applying the slurry-like electrode material of the present embodiment to the surface of the current collector foil include various application methods such as an extrusion coater, a reverse roller, a doctor blade, and an applicator.

It is important that the two types of solvents (first solvent and second solvent) used in the present embodiment are appropriately selected and used. Such a solvent should be selected on the basis of the solubility of the solidifying agent of the present embodiment, or the components of the binder that also serves as the solidifying agent, and the mutual solubility of the solvent.

Examples of the first solvent include aprotic polar solvents represented by N-methylpyrrolidone, dimethyl sulfoxide, propylene carbonate, dimethylformamide, γ-butyrolactone, and the like, or a mixed solution containing two or more of these. . Examples of the second solvent include protic solvents represented by water, ethanol, isopropyl alcohol, acetic acid, and the like, or a mixed solution containing two or more of these, but are limited to the examples given here. Is not to be done. In some cases, it is possible to select aliphatic saturated hydrocarbons, aliphatic amines, esters, ethers, various halogen-based solvents, and the like as the second solvent. Further, in some cases, it is possible to select to exchange the first solvent and the second solvent. The selection of the solvent depends on the selection of the solidifying component used for the electrode film and the combination of the two types of solvents.

The solidification chamber of the present embodiment includes a solidification liquid supply device for bringing the solidification liquid made of the second solvent into contact with the coating film on the current collector foil containing the first solvent. Further, the solidification chamber has a solidification liquid in which the contact area of the solidification liquid is not less than the end of the application width in the direction perpendicular to the conveyance direction of the current collector foil and within the current collection tab attachment position of the non-application part of the current collector foil A contact mechanism is provided. Specifically, it is a method in which the solidified liquid is brought into contact with the coating film surface using a spray nozzle provided in the solidified liquid supply device, and only in the above-described spray region by adjusting the type and arrangement of the spray nozzle. Contact the solidified solution.

The solidification step includes a method of controlling the contact area of the solidified liquid by attaching a spray mask between the spray nozzle and the coating film. The method of controlling the contact region of the solidified liquid ejected from the spray nozzle with the spray mask can control the spray region more easily than the method of controlling the spray region by the type and arrangement of the spray nozzle. A more specific configuration of the solidification device will be clarified in Examples described later.

In this embodiment, since the binder does not move in the coating film in the drying process after the solidification process, the method for drying the solidified coating film is not limited to general hot air drying. That is, a heating method of irradiating electromagnetic waves such as infrared rays, far infrared rays or visible light may be used, or a dielectric heating method using a high frequency electric field may be used. Furthermore, an induction heating method using a change in magnetic flux can be used, or a contact heating method using a heating roll or a hot plate incorporating a heater can be used.

The lithium ion secondary battery that can be provided by the present embodiment can be manufactured in the same manner as a conventional lithium ion secondary battery except that it includes positive and negative electrode plates manufactured by the above-described method. . That is, there is no particular limitation on the structure and size of the battery outer container that houses these electrode plates, or the structure of the wound body or laminate including the positive and negative electrode plates as main components.

As described above, the manufacture of the present embodiment that can maintain / improve the quality of the electrode plate by manufacturing the electrode plate in which the binder is almost uniformly distributed in the electrode film at a low cost while improving the productivity. Although the method and the manufacturing apparatus have been described, preferred examples for realizing the present embodiment will be described below.

(Example 1)
In the first embodiment, the spray nozzle is placed in the solidification chamber so that the contact width of the solidified liquid along the direction orthogonal to the conveying direction of the current collector foil is equal to or larger than the width of the coating film and within the current collecting tab attachment position. An electrode plate manufacturing apparatus in which is disposed will be described.

As shown in FIG. 2, the solidification chamber 18 of the first embodiment is surrounded by an outer wall 21 made of metal or synthetic resin, and a space isolated from the outside is provided on the conveyance path of the current collector foil 15. It has been. The current collector foil 15 coated with the electrode material coating film 22 is solidified by a roller transport system 14 in a solidification chamber having a spray nozzle 23, a solidified liquid tank 25 in which a solidified liquid 24 is stored, a supply pump 26, and a waste liquid tank 27. 18 is introduced. Then, the coating film 22 is solidified by coming into contact with the solidified liquid 24 supplied from the spray nozzle 23 and is carried out to the next drying apparatus.

As shown in FIG. 3, the spray pattern 33 of the solidified liquid 24 sprayed on the surface of the coating film 22 is a current collecting tab in which the spray region end in the coating film width direction is installed at a non-coating portion of the current collecting foil 15. It is inside the attachment position 28. Therefore, the electrode material component in the coating film 22 does not flow out to the current collecting tab attachment position 28.

The shape of the spray pattern 33 is not limited to the elliptical shape shown in FIG. 3 as long as the end of the spray region in the application width direction is inside the current collecting tab attachment position 28. It may be a combined pattern or the like. Furthermore, the flow rate distribution in the spray region has a uniform flow rate distribution as shown in FIG. 4, and the position where the flow rate is 50% of the flow rate at the center of the spray nozzle 23 is equal to or greater than the end of the coating film width. The spray region having such a uniform flow distribution may be realized by a single nozzle or by combining a plurality of nozzles. By using the spray nozzle 23 having such a spray pattern and flow rate distribution, the solidified liquid can be brought into contact with the coating film surface evenly, and the in-plane uniformity of the electrode film can be improved.

As the type of the spray nozzle 23, a one-fluid nozzle that ejects only a liquid and a two-fluid nozzle that ejects a mixture of liquid and gas can be used. From the viewpoint of reducing the impact when water contacts the coating film solidified by spraying, a two-fluid nozzle capable of spraying finer droplets is desirable. Further, by setting the average particle diameter D50 of the spray particles sprayed from the spray nozzle 23 to 20 μm or less, more preferably 10 μm or less, damage such as coating film defects can be prevented.

As the injection pattern of a single nozzle, a flat pattern, a straight pattern, a full cone pattern, or the like can be used depending on the shape of the nozzle orifice. Further, as the flow rate distribution, it is sufficient that the uniform flow rate distribution shown in FIG. 4 is formed when the nozzles are combined, and the nozzle alone has a spray nozzle having various flow rate distributions such as a mountain-shaped flow rate distribution and an equal flow rate distribution. Can be used. Further, the spray hitting force per unit area is preferably adjusted to 5 g / cm or less, more preferably 1 g / cm from the viewpoint of damage to the coating film.

Next, each step relating to the production of the lithium ion secondary battery of Example 1 will be described more specifically.

As the positive electrode active material, lithium nickel cobalt manganate as a lithium transition metal composite oxide can be selected. Graphite powder and acetylene black, which are conductive assistants, and polyvinylidene fluoride (hereinafter referred to as PVdF), which is a solidifying solution and binder, are mixed at a weight ratio of 85: 8: 2: 5, and the first N-methyl-2-pyrrolidone (hereinafter referred to as NMP) as a solvent was sequentially added, and these components were kneaded with a planetary mixer to prepare a highly viscous positive electrode slurry. In the positive electrode slurry, the solidifying liquid / binder component was dissolved in NMP. The viscosity of the positive electrode slurry measured with a rotational viscometer was about 10 Pa · s. Next, the kneaded positive electrode slurry was applied to an aluminum foil (positive electrode current collector foil) having a thickness of 20 μm and a width of 200 mm with an applicator so as to have a thickness of 100 μm and a width of 150 mm. Here, the current collecting tab attachment position in the non-application part was 15 mm from the coating film terminal.

The above process is a coating process for applying a slurry-like electrode material on the surface of the current collector foil. Next, the aluminum foil coated with the electrode material was carried into the solidification chamber 18 shown in FIG. 2, and the electrode material was solidified by spraying the solidified liquid onto the coating film surface. Pure water was used as the solidified liquid, and an internal mixing type two-fluid nozzle was used as the spray nozzle. The average particle diameter D50 of the spray particles ejected from the two-fluid nozzle was 10 μm. The distance from the spray nozzle to the coating film was 100 mm, the spray pressure was 0.1 MPa, and the spray hitting force was adjusted to 1 g / cm. The spray pattern was a full cone circular shape, the spray area was 80 mm in diameter, and the 50% flow area was 70 mm. Two spray nozzles were arranged in the width direction of the coating film and sprayed onto the coating film surface.

The above process is a solidification process in which the electrode material is solidified by bringing the solidified liquid composed of the second solvent different from the first solvent contained in the electrode material into contact with the electrode material.

The above solidification phenomenon is a phenomenon in which water adhering by spraying penetrates while mutually dissolving with NMP in the coating film, and the solubility of the binder contained in the coating film decreases due to an increase in the moisture concentration in the coating film. It is. The deposited binder bonds the positive electrode particles and the like, and solidifies the coating film. Since the electrode material solidified in this way loses fluidity and adhesiveness and is held on the aluminum foil, it can sufficiently withstand a contact-type conveying method in which a roller is brought into contact.

Next, the aluminum foil holding the solidified coating film is transported to a drying chamber and dried in a hot air drying oven at 120 ° C. for 10 minutes to evaporate and remove pure water and NMP contained in the solidified coating film. And the positive electrode plate for lithium ion secondary batteries was manufactured. The above process is a drying process in which the solvent component is removed from the electrode material and dried.

As a result of measuring the composition distribution along the thickness direction of the cross section of the positive electrode plate obtained in Example 1, the amount of the binder on the aluminum foil side was 5.2%, the surface side was 4.4%, and the aluminum foil side The amount of the binder was 16% more. Moreover, as a result of observing the tab attachment position surface of aluminum foil, adhesion of electrode material was not confirmed.

(Example 2)
In the second embodiment, the spray nozzle is placed in the solidification chamber so that the contact width of the solidified liquid along the direction orthogonal to the conveying direction of the current collector foil is equal to or greater than the width of the coating film and within the current collector tab attachment position. An electrode plate manufacturing apparatus in which a spray mask is disposed will be described.

As shown in FIG. 5, the solidification chamber 18 of the second embodiment is surrounded by an outer wall 21 made of metal or synthetic resin, as in the first embodiment. An isolated space is provided. The current collector foil 15 coated with the electrode material coating film 22 is solidified by a roller transport system 14 in a solidification chamber having a spray nozzle 23, a solidified liquid tank 25 in which a solidified liquid 24 is stored, a supply pump 26, and a waste liquid tank 27. 18 is introduced. Then, the coating film 22 is solidified by coming into contact with the solidified liquid 24 supplied from the spray nozzle 23 and is carried out to the next drying apparatus.

As the spray nozzle 23 of the second embodiment, the same type of spray nozzle as that described in the first embodiment can be used. However, unlike the first embodiment, the spray nozzle 23 is disposed between the spray nozzle 23 and the roller conveyance system 14. Since the spray area is determined by the spray mask 29 arranged in the above, the shape of the spray pattern is not limited.

Fig. 6 shows an example of a spray mask. The spray mask 29 provided with an opening in the center has an inclined portion 30 that is high on the center side and low on the outer peripheral side so that excessive solidified liquid does not flow to the coating film side. In the second embodiment, an example of the linear inclined portion 30 has been described. However, the spray mask 29 in which the inclined portion 30 has a round (R) may be used. Further, a discharge groove 31 for discharging the excessive solidified liquid to the outside is provided on the outer periphery of the spray mask 29. By using such a spray mask 29, it becomes possible to control the spray area more easily and prevent the electrode material from flowing out to the current collecting tab mounting position.

The positive electrode slurry prepared in Example 1 was applied to an aluminum foil (positive electrode current collector foil) having a thickness of 20 μm and a width of 200 mm with an applicator so as to have a thickness of 100 μm and a width of 150 mm. Here, the current collecting tab attachment position in the non-application part was 15 mm from the coating film terminal.

Next, the aluminum foil coated with the electrode material was carried into the solidification chamber 18 shown in FIG. 2, and the electrode material was solidified by spraying the solidified liquid onto the coating film surface. Pure water was used as the solidified liquid, and an internal mixing type two-fluid nozzle was used as the spray nozzle. The average particle diameter D50 of the spray particles ejected from the two-fluid nozzle was 10 μm. The distance from the spray nozzle to the coating film was 100 mm, the spray pressure was 0.1 MPa, and the spray hitting force was adjusted to 1 g / cm. The spray pattern was a full cone circular shape, the spray area was 100 mm in diameter, and the 50% flow area was 80 mm. Two spray nozzles were arranged in the width direction of the coating film, a spray mask was attached between the spray nozzle and the coating film, and the surface of the coating film was sprayed. Here, the opening diameter of the spray mask was 100 mm in the coating width direction and 50 mm in the transport direction.

Next, the aluminum foil holding the solidified coating film is transported to a drying chamber and dried in a hot air drying oven at 120 ° C. for 10 minutes to evaporate and remove pure water and NMP contained in the solidified coating film. And the positive electrode plate for lithium ion secondary batteries was manufactured.

As a result of measuring the composition distribution along the thickness direction of the cross section of the positive electrode plate obtained in Example 2, the amount of the binder on the aluminum foil side was 5.0%, the surface side was 4.3%, and the aluminum foil side The amount of the binder was 14% more. Moreover, as a result of observing the tab attachment position surface of aluminum foil, adhesion of electrode material was not confirmed.

(Example 3)
In this third embodiment, an electrode plate manufacturing apparatus in which a heater is attached to the spray mask used in the second embodiment will be described.

The solidification chamber 18 of the second embodiment is surrounded by a metal or synthetic resin outer wall 21 as in the second embodiment, and a space isolated from the outside is provided on the conveyance path of the current collector foil 15. ing. The current collector foil 15 coated with the electrode material coating film 22 is solidified by a roller transport system 14 in a solidification chamber having a spray nozzle 23, a solidified liquid tank 25 in which a solidified liquid 24 is stored, a supply pump 26, and a waste liquid tank 27. 18 is introduced. Then, the coating film 22 is solidified by coming into contact with the solidified liquid 24 supplied from the spray nozzle 23 and is carried out to the next drying apparatus.

A spray mask 29 with a built-in heater is disposed between the spray nozzle 23 and the roller conveyance system 14.

Fig. 7 shows an example of a spray mask. The spray mask 29 has an inclined portion 30 that is high on the center side and low on the outer peripheral side so that excessive solidified liquid does not flow to the coating film side. A heater 32 is built in the inclined portion 30. In the third embodiment, as in the second embodiment, an example of the linear inclined portion 30 is shown. However, the spray mask 29 in which the inclined portion 30 is rounded (R) may be used. Further, a discharge groove 31 for discharging the excessive solidified liquid is provided on the outer periphery of the spray mask 29.

Since the heater 32 is built in the inclined portion 30, excess solidified liquid sprayed on the surface of the spray mask 29 evaporates, so that the solidified liquid collected on the surface of the spray mask 29 drops and adheres to the coating film. The phenomenon can be prevented. By using such a spray mask, even when a larger amount of solidified liquid is sprayed than in Example 2, it is possible to control the spray area with high accuracy and prevent the adhesion of excess solidified liquid. The effect of preventing the electrode material from flowing out to the tab attachment position and the uniformity in the in-plane direction of the electrode film can be improved.

As a result of measuring the composition distribution along the thickness direction of the cross section of the positive electrode plate obtained in Example 3, the amount of the binder on the aluminum foil side was 5.2%, the surface side was 4.5%, and the aluminum foil side The amount of the binder was 15% more. Moreover, as a result of observing the tab attachment position surface of aluminum foil, adhesion of electrode material was not confirmed.

(Comparative Example 1)
Here, the positive electrode slurry of Example 1 was applied to an aluminum foil (positive electrode current collector foil) having a thickness of 20 μm with an applicator so as to have a thickness of 100 μm. NMP contained in the film was removed by evaporation to produce a positive electrode plate for a lithium ion secondary battery. The manufacturing method of Comparative Example 1 corresponds to a conventional manufacturing method.

As a result of measuring the composition distribution in the thickness direction of the cross section of the positive electrode plate obtained in Comparative Example 1, the amount of the binder on the aluminum foil side was decreased as compared with the vicinity of the surface. Specifically, the amount of binder on the aluminum foil side was 2.2%, the surface side was 6.5%, and the aluminum foil side was 66% less.

(Comparative Example 2)
Here, the positive electrode slurry of Example 1 was applied to an aluminum foil (positive electrode current collector foil) having a thickness of 20 μm with an applicator so as to have a thickness of 100 μm, and immersed in pure water for 20 seconds to solidify the electrode material. Then, it dried at 120 degreeC for 10 minute (s) in the hot air drying furnace, the pure water and NMP which were contained in the coating film were removed by evaporation, and the positive electrode plate for lithium ion secondary batteries was manufactured. The manufacturing method of this comparative example 2 is a manufacturing method which does not consider the outflow of the electrode material in the solidification process.

As a result of measuring the composition distribution in the thickness direction of the cross section of the positive electrode plate obtained in Comparative Example 2, the amount of the binder on the aluminum foil side was increased as compared with the vicinity of the surface. Specifically, the amount of binder on the aluminum foil side was 5.3%, the surface side was 4.0%, and the aluminum foil side was 25% more. Moreover, the binder which is an electrode material had adhered from the observation result of the current collection tab attachment position surface.

(Effects of Examples 1 to 3)
As in Examples 1 to 3, by providing the solidification step prior to the electrode material drying step, the difference between the binder concentration on the current collector foil side and the binder concentration on the surface side within the coating film is caused by the solidification step. Compared with Comparative Example 1 that was not provided, the binder concentration distribution became uniform.

In Comparative Example 1, since the coating film is in a liquid state at the start of drying, movement of components such as a binder, that is, convection and diffusion occurs in the film, and it is estimated that the distribution of the electrode material is biased after drying. On the other hand, in Examples 1 to 3, the coating film was solidified in the solidification step, and at the same time, the components were fixed and the distribution was reduced because the components did not move during drying. Thereby, since the binder density | concentration on the side of current collection foil becomes relatively high, the adhesiveness of an electrode film and current collection foil became good, and the effect which the durability of a lithium ion secondary battery improved was acquired.

Also, as in Examples 1 to 3, by controlling the region where the solidified liquid contacted the coating film, it was possible to prevent the electrode material from flowing out to the non-coated portion of the current collector foil. In Comparative Example 2, since the binder component adhered to the current collecting tab mounting position installed in the non-coated portion, the resistance between the current collecting foil and the current collecting tab increased, and the capacity and cycle characteristics of the lithium ion secondary battery were reduced. There is a risk of getting worse.

Furthermore, from the characteristics of the first to third embodiments, it is possible to use a contact-type roller conveyance system that comes into contact with the coating film when conveying the current collector foil holding the solidified coating film. In other words, the contact roller transport system 14 can be used even in the case of double-sided batch application as shown in FIG. Can be used.

The effects of the embodiments described so far can be obtained not only with the positive electrode plate made of the positive electrode material but also with the negative electrode plate. Each of the embodiments is merely an example of implementation of the present invention, and the present invention can be implemented in various forms without departing from the technical idea or main features thereof. Further, the present invention may be implemented by combining the first to third embodiments.

The present invention can be used for manufacturing a lithium ion secondary battery.

DESCRIPTION OF SYMBOLS 11 Coating part 12 Coating means 13 Current collection foil roll 14 Roller conveyance system 15 Current collection foil 16 Drying chamber 18 Solidification chamber 21 Outer wall 22 Coating film 23 Spray nozzle 24 Solidification liquid 25 Solidification liquid tank 26 Supply pump 27 Waste liquid tank 28 Collection Electric tab attachment position 29 Spray mask 30 Inclined portion 31 Discharge groove 32

Heater

51, 51A,

51B Coating portion

52, 52A, 52B Coating means 53 Current collecting foil rolls 54, 54A, 54B Roller transport system 55 Current collecting

foil

56 , 56A, 56B Drying chamber 57 Electrode roll 58 Non-contact conveyance system

Claims

A coating portion for applying a slurry-like electrode material containing a positive electrode or negative electrode active material, a binder, a solidifying agent, and a first solvent to the surface of the current collector foil;
A solidification chamber for solidifying the slurry-like electrode material by bringing a solidified liquid into contact with the slurry-like electrode material applied to the surface of the current collector foil;
A drying chamber for removing the liquid component contained in the electrode material solidified in the solidification chamber and drying the electrode material;
Have
The solidification chamber has a contact width of the solidified liquid along a direction orthogonal to a conveying direction of the current collector foil, which is equal to or greater than a width of the slurry-like electrode material applied to the surface of the current collector foil. An apparatus for producing a lithium ion secondary battery, comprising a solidified liquid contact mechanism defined within a foil current collecting tab attachment position.
In the manufacturing apparatus of the lithium ion secondary battery according to claim 1,
The said solidification liquid contact mechanism is a manufacturing apparatus of a lithium ion secondary battery which is a spray nozzle.
In the manufacturing apparatus of the lithium ion secondary battery according to claim 2,
The flow rate distribution of the solidified liquid in the spray region of the spray nozzle has a uniform flow rate distribution,
An apparatus for manufacturing a lithium ion secondary battery, wherein the position at which the flow rate is 50% of the flow rate at the center of the spray nozzle is equal to or more than the end of the width of the slurry-like electrode material applied to the current collector foil surface.
In the manufacturing apparatus of the lithium ion secondary battery according to claim 2,
An apparatus for manufacturing a lithium ion secondary battery, wherein a spray mask for defining a spray region of the spray nozzle is provided between the spray nozzle and the current collector foil.
In the manufacturing apparatus of the lithium ion secondary battery according to claim 4,
The said spray mask is a manufacturing apparatus of a lithium ion secondary battery which has an inclination part and the discharge groove for discharging | emitting the excessive solidified liquid adhering to the surface of the said inclination part.
In the manufacturing apparatus of the lithium ion secondary battery according to claim 5,
The inclined part is an apparatus for manufacturing a lithium ion secondary battery in which a heater is incorporated.
In the manufacturing apparatus of the lithium ion secondary battery according to claim 1,
The manufacturing apparatus of a lithium ion secondary battery which has a contact-type roller conveyance system which contacts the surface of the said current collection foil as a conveyance system which conveys the said current collection foil.
(A) a step of applying a slurry-like electrode material containing at least a positive or negative active material, a binder, a solidifying agent, and a first solvent to the surface of the current collector foil;
(B) a step of solidifying the slurry-like electrode material by bringing a solidified liquid into contact with the slurry-like electrode material applied to the surface of the current collector foil;
(C) removing the liquid component contained in the solidified electrode material and drying the electrode material;
Have
In the step (b), the contact width of the solidified liquid along the direction orthogonal to the conveying direction of the current collector foil is equal to or greater than the width of the slurry-like electrode material applied to the surface of the current collector foil. A method for producing a lithium ion secondary battery, wherein the current collecting tab is located within the current collecting tab attachment position of the current collecting foil.
In the manufacturing method of the lithium ion secondary battery according to claim 8,
The first solvent is an aprotic polar solvent typified by N-methylpyrrolidone, dimethyl sulfoxide, propylene carbonate, dimethylformamide, γ-butyrolactone, or a mixed solution containing two or more thereof. A method for manufacturing an ion secondary battery.
In the manufacturing method of the lithium ion secondary battery according to claim 8,
The solidified liquid is a second solvent having a property that the solidifying agent contained in the slurry-like electrode material is insoluble and a property that is mutually soluble with the first solvent contained in the slurry-like electrode material. A method for producing a lithium ion secondary battery, comprising:
In the manufacturing method of the lithium ion secondary battery according to claim 10,
The method for producing a lithium ion secondary battery, wherein the second solvent is water, ethanol, isopropyl alcohol, a protic solvent typified by acetic acid, or a mixed solution containing two or more of these.
In the manufacturing method of the lithium ion secondary battery according to claim 8,
The slurry-like electrode material is a method for producing a lithium ion secondary battery, further comprising a conductive additive.
In the manufacturing method of the lithium ion secondary battery according to claim 8,
The method for manufacturing a lithium ion secondary battery, wherein the binder is a polyvinylidene fluoride-based polymer, a rubber-based polymer, or a mixture thereof.
In the manufacturing method of the lithium ion secondary battery according to claim 8,
The binder is a method for producing a lithium ion secondary battery, which also serves as the solidifying agent.
A lithium ion secondary battery obtained by the production apparatus according to claim 1 or the production method according to claim 8.