JP2014192043A - Apparatus and method for manufacturing lithium-ion battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the footprint of an apparatus for manufacturing a lithium-ion battery.SOLUTION: An apparatus for manufacturing a lithium-ion battery including a laminate, in which a cathode sheet having a cathode electrode layer formed thereon and an anode sheet having an anode electrode layer formed thereon are alternately laminated via a separator layer, includes a conveyance mechanism for conveying an electrode foil 1. The apparatus for manufacturing a lithium-ion battery also includes a coating unit 2 for applying an electrode material onto the electrode foil 1, a solidification chamber 8 for supplying a solidifying liquid 8b to the electrode material, and a drying chamber 6 for drying. An electrode foil 1c in the solidification chamber 8 is arranged below an electrode foil 1d in the drying chamber 6 by the conveyance mechanism so as to form an obtuse angle with the electrode foil 1d.

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method for a lithium ion battery.

  A lithium ion battery is a secondary battery in which a laminate in which positive electrode sheets and negative electrode sheets are alternately laminated via separators is enclosed in an outer package together with an electrolytic solution. As the exterior body, a cylindrical or square can, a laminate film having Al (aluminum) or the like as a base body, or the like is used. The manufacturing method and appearance of the lithium ion battery vary greatly depending on the structure and type of the exterior body, but the basic components for operating the battery are the same regardless of which exterior body is used.

  That is, the positive electrode sheet has a basic structure in which an electrode layer made of an electrode material (positive electrode active material) is provided on one or both surfaces of the electrode foil, and the negative electrode sheet has an electrode material (negative electrode active material) on one or both surfaces of the electrode foil. A basic structure provided with an electrode layer made of a material. A separator layer is provided between the electrode layer on the positive electrode sheet and the electrode layer on the negative electrode sheet in order to prevent both electrode layers from short-circuiting. A lithium ion battery is manufactured by forming a laminate including a positive electrode sheet, a separator, and a negative electrode sheet, and enclosing the laminate together with an electrolytic solution containing lithium ions.

  An example of a method for manufacturing such a lithium ion battery is described in Patent Document 1 (Japanese Patent Laid-Open No. 2006-73234). The outline of the electrode manufacturing process in Patent Document 1 will be described as follows by taking the positive electrode as an example.

  First, a positive electrode active material powder material, a conductive material powder, a binder solution and an organic solvent are kneaded to produce a slurry-like paste (electrode material), and this paste is collected using a coating means such as a die coater. Apply thin and evenly on the aluminum electrode foil. Thereafter, the applied paste is dried to form an electrode film (corresponding to the electrode layer). Next, an electrode for a lithium ion battery is subjected to a calendar process (a process of crushing and stretching with a roll) for adjusting the electrode film to a predetermined thickness or a slit process for processing the electrode film into a predetermined shape. Form.

JP 2006-73234 A

  As described above, in the manufacturing process of a lithium ion battery, an electrode layer is formed through a series of processes including manufacturing of paste-like electrode material, application of electrode material to electrode foil and drying, or a combination of these processes. It is necessary to form an electrode sheet.

  Of the series of steps described above, in the drying step, the electrode material is dried at a high temperature. At that time, when the electrode material is dried at a high temperature in a short time, the binder that binds the active material contained in the electrode material is the electrode material. Segregates on the surface. As a result, a phenomenon occurs in which the adhesion between the electrode material and the electrode foil is deteriorated.

  Therefore, it is conceivable to employ a method of gradually raising the temperature of the electrode material and drying the electrode material applied to the electrode foil so that the binder does not segregate. However, in this case, the length of the drying furnace (drying section) used in the drying process is increased, and the size of the lithium ion battery manufacturing apparatus is increased.

  Therefore, the inventor of the present application examined a manufacturing apparatus for a lithium ion battery of the first comparative example as shown in FIG.

  FIG. 7 is a schematic view schematically showing the structure of an electrode manufacturing apparatus constituting the lithium ion battery manufacturing apparatus as the first comparative example. In the manufacturing apparatus shown in FIG. 7, an electrode material used to form an electrode layer constituting a positive electrode or a negative electrode of a lithium ion battery is used by using a die coater (coating means) 30 installed in the coating unit 20. A thin and uniform coating is applied to the surface of the electrode foil 1 supplied from the collecting electrode foil roll 40.

  Subsequently, the electrode foil 1 coated with the electrode material is transported to the solidification chamber 80 using a roller transport system 50 that transports the electrode foil 1 at a constant speed while being in contact with the back surface of the electrode foil 1. In the solidification chamber 80, the solidified liquid is supplied from the nozzle 80a to the electrode material applied on the electrode foil 1, and the concentration of the solvent contained in the electrode material is reduced to precipitate the binder.

  Subsequently, the electrode foil 1 is transported to the drying chamber 60 by the roller transport system 50. Thereafter, the solvent component in the electrode material is heated and evaporated in the drying chamber 60 to dry the electrode material, thereby forming an electrode layer. The electrode foil roll 70 that has wound up the electrode foil 1 that has undergone the drying step is supplied to the next step.

  That is, in the manufacturing apparatus shown in FIG. 7, the solidification chamber (solidification part) 80 in which the binder contained in the electrode material apply | coated on the electrode foil 1 is precipitated in the front | former stage of the drying chamber 60, thereby, The drying chamber (drying furnace, drying section) 60 has a reduced length.

  However, in the manufacturing apparatus shown in FIG. 7, it is necessary to supply the solidified liquid to the electrode material on the electrode foil 1 by spraying or immersion in the solidifying chamber 80 provided in the preceding stage of the drying chamber 60. In order to recover, it is necessary to install a pan (container) 80b for recovery of the solidified liquid which has been increased in size. Alternatively, it is necessary to install a pan 80b for collecting the solidified liquid over a wide range.

  That is, since the electrode foil 1 moves in the horizontal direction, the waste liquid of the solidified liquid supplied from the nozzle 80a easily moves in the horizontal direction. Therefore, the pan 80b for recovering the solidified liquid (waste liquid) corresponding to a large size or a wide range. Must be installed. On the other hand, when the method of spraying the solidified liquid by spraying is employed, a large chamber for preventing the solidified liquid from being diffused in the apparatus (solidified chamber 80) is required.

  As a result, the footprint (installation area) of the lithium ion battery manufacturing apparatus is increased, leading to an increase in the cost of the manufacturing apparatus, thereby increasing the amount of material to be supplied, resulting in an increase in manufacturing cost. I found a problem.

  In order to increase the permeability of the solidified liquid, a large amount of the solidified liquid is required. However, when spraying is employed, a large amount of the solidified liquid is sprayed and it is difficult to maintain the uniformity of the solidified liquid. I also found out.

  Further, the solidified liquid has a low viscosity. Therefore, it is difficult to uniformly hold the solidified liquid on the electrode material applied on the electrode foil 1 that moves at high speed during production, and as a result, unevenness in the permeation distribution of the solidified liquid occurs. It has been found that the quality of the ion battery is lowered.

  An object of the present invention is to provide a lithium-ion battery manufacturing apparatus and a lithium-ion battery manufacturing method capable of reducing the footprint and manufacturing cost.

  In addition, another object of the present invention is to provide a lithium ion battery manufacturing apparatus and a lithium ion battery manufacturing method capable of improving the uniformity and permeability of application of the solidified liquid and improving the quality of the lithium ion battery. It is to provide.

  The above object and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  Of the embodiments disclosed in the present application, the outline of typical ones will be briefly described as follows.

  A lithium ion battery manufacturing apparatus according to an embodiment is a lithium ion battery manufacturing apparatus including a laminate in which positive electrode sheets and negative electrode sheets are alternately stacked via separator layers, and transports an electrode foil. A mechanism, an application part for applying the electrode material on the electrode foil, a solidification part for supplying a solidified liquid to the surface of the electrode material applied on the electrode foil, and drying the electrode material to form an electrode layer And a drying section. Furthermore, the electrode foil in the solidifying part is arranged below the position of the electrode foil in the drying part and so as to form an obtuse angle with the electrode foil in the drying part by the transport mechanism.

  Moreover, the manufacturing method of the lithium ion battery which is one Embodiment is a manufacturing method of a lithium ion battery provided with the laminated body by which the positive electrode sheet and the negative electrode sheet were laminated | stacked alternately via the separator layer, and electrode material is an electrode. An application process for applying on the foil, a solidification process for supplying the solidified liquid to the surface of the electrode material applied on the electrode foil, and a drying process for forming the electrode layer by drying the electrode material supplied with the solidified liquid And a process. Furthermore, in the solidification step, the solidified liquid is supplied in a state where the electrode foil is disposed below the position of the electrode foil in the drying step and so as to form an obtuse angle with the electrode foil in the drying step.

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

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing apparatus of the lithium ion battery which can aim at reduction of a footprint and reduction of manufacturing cost can be provided.

  In addition, according to the present invention, it is possible to provide a method for manufacturing a lithium ion battery that can reduce the footprint and the manufacturing cost.

  Moreover, according to this invention, the manufacturing apparatus of the lithium ion battery which can improve the uniformity and permeability of application | coating of a solidification liquid, and can improve the quality of a lithium ion battery can be provided.

  Moreover, according to this invention, the manufacturing method of the lithium ion battery which can improve the uniformity and permeability of application | coating of a solidification liquid, and can improve the quality of a lithium ion battery can be provided.

It is the schematic which shows an example of the structure of the electrode manufacturing apparatus which comprises the manufacturing apparatus of the lithium ion battery in embodiment of this invention. It is sectional drawing which shows an example of the structure of the lithium ion battery manufactured by the manufacturing method of the lithium ion battery of embodiment of this invention. It is the figure which compared the characteristic of the electrode layer of embodiment of this invention, and the electrode layer of a 2nd comparative example. It is the schematic which shows the structure of the electrode manufacturing apparatus which comprises the manufacturing apparatus of the lithium ion battery of the 1st modification in embodiment of this invention. It is the schematic which shows the structure of the electrode manufacturing apparatus which comprises the manufacturing apparatus of the lithium ion battery of the 2nd modification in embodiment of this invention. It is the schematic which shows the structure of the electrode manufacturing apparatus which comprises the manufacturing apparatus of the lithium ion battery of the 3rd modification in embodiment of this invention. It is the schematic of the electrode manufacturing apparatus which comprises the manufacturing apparatus of the lithium ion battery shown as a 1st comparative example.

  In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

  Further, in the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments, but they are not irrelevant to each other unless otherwise specified. The other part or all of the modifications, details, supplementary explanations, and the like are related.

  Also, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), particularly when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to that specific number. Furthermore, it may be a specific number or more.

  Further, in the following embodiments, the constituent elements (including element steps) are not necessarily indispensable unless otherwise specified and clearly considered essential in principle. Needless to say.

  Further, in the following embodiments, regarding constituent elements and the like, when “consisting of A”, “consisting of A”, “having A”, and “including A” are specifically indicated that only those elements are included. It goes without saying that other elements are not excluded except in the case of such cases. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Hereinafter, embodiments 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. Further, even a plan view may be hatched for easy understanding of the drawing.

(Embodiment)
In the lithium ion battery manufactured by the manufacturing method or the manufacturing apparatus according to the present embodiment, a laminate in which positive electrode sheets and negative electrode sheets are alternately stacked via a separator layer is formed together with an electrolyte solution (for example, a cylindrical type). Secondary battery enclosed in a container. The positive electrode sheet is formed with a positive electrode layer, while the negative electrode sheet is formed with a negative electrode layer.

  In the following description, the positive electrode sheet and the negative electrode sheet are collectively referred to as an “electrode sheet”. The paste-like material applied to the surface of the electrode foil to form the electrode layer is called “electrode material”, and the paste-like material applied to the base material or the electrode layer to form the separator layer The material is called “separator material”. Furthermore, the electrode material and the separator material are collectively referred to as “paste”. The electrode material and the separator material referred to in the present application are liquid substances having fluidity including liquids such as a binder solution and an organic solvent. In the following description, the term “surface of the electrode foil” refers to only the front surface, not the entire surface including the front surface and the back surface of the electrode foil.

  The electrode material used to form the electrode layer constituting the positive or negative electrode of the lithium ion battery is, for example, an active material powder, a conductive material powder, a binder material for binding these powders, etc. It is a highly viscous slurry liquid dispersed in a solvent. Examples of the organic solvent include N-methylpyrrolidone (NMP).

  Next, a lithium ion battery manufacturing apparatus and a lithium ion battery manufacturing method in the present embodiment will be described with reference to FIG. FIG. 1 is a schematic view showing an example of the structure of a single-side coating type electrode manufacturing apparatus that constitutes a lithium ion battery manufacturing apparatus according to an embodiment of the present invention.

  First, the single-sided application type electrode manufacturing apparatus shown in FIG. 1 will be described.

  The electrode manufacturing apparatus includes a plurality of rollers (conveying mechanism) 5 that conveys an electrode foil (also referred to as a current collector foil) 1, a coating part (application part) 2 that applies an electrode material onto the electrode foil 1, And a drying chamber (drying unit) 6 for forming the electrode layer by drying the electrode material. Furthermore, between the coating part 2 and the drying chamber 6, it has the solidification chamber (solidification part) 8 which supplies the solidification liquid 8b to the surface of the said electrode material apply | coated on the electrode foil 1. FIG.

  That is, in the electrode manufacturing apparatus of the present embodiment, the solidification chamber 8 is provided in the previous stage (upstream side) of the drying chamber 6 in the transport direction S of the electrode foil 1, and thereby the length of the drying chamber 6 is increased. The length is relatively short. This is because, in the solidification chamber 8, the drying time can be shortened by supplying the solidification liquid 8b to the surface of the electrode material applied on the electrode foil 1 and performing the solidification treatment of the electrode material. As a result, the length of the drying chamber 6 can be made relatively short.

  The electrode material contains a solvent that is compatible with water and a binder that is hardly soluble in water. Therefore, in the solidifying chamber 8, the solidified liquid 8b is applied to the surface of the electrode material, so that the concentration of the solvent contained in the electrode material is lowered to precipitate the binder, thereby shortening the drying time. It becomes possible to do.

  Therefore, the electrode foil 1 fed out from the collecting electrode foil roll 4 which is an unwinding machine is coated with the electrode material in the coating unit 2, and then the solidified liquid 8 b is applied to the surface of the electrode material in the solidification chamber 8. Is supplied. Furthermore, it is conveyed to the drying chamber 6 and is dried, whereby the electrode layer is formed on the electrode foil 1 and then wound around an electrode foil roll 7 that is a winder. And the electrode foil 1 wound up by the electrode foil roll 7 is conveyed to the following process.

  The electrode foil 1 is transported by a plurality of rollers 5 provided as a transport system for the electrode foil 1 and supporting one surface of the electrode foil 1, and is fed in a predetermined direction by the rotation of each roller 5. It is done.

  In the coating unit 2, the electrode material is discharged from a die coater (also referred to as an electrode coater) 3, whereby the electrode material is applied onto the electrode foil 1.

  Therefore, the electrode manufacturing apparatus according to the present embodiment is characterized in that the electrode foil 1c in the solidification chamber 8 is positioned below the position of the electrode foil 1d in the drying chamber 6 and an obtuse angle with the electrode foil 1d in the drying chamber 6 ( a transport system (transport mechanism) arranged to form θ1).

  That is, the position of the electrode foil 1c in the solidification chamber 8 becomes a position below the position of the electrode foil 1d in the drying chamber 6 due to the arrangement of the roller 5 as a transport mechanism, and in that case, the electrode foil 1c in the solidification chamber 8 However, it arrange | positions so that the electrode foil 1d of the drying chamber 6 may form an obtuse angle ((theta) 1).

  Here, the conveyance mechanism that forms the conveyance system includes an electrode foil roll 4 for collecting the electrode foil 1, an electrode foil roll 7 that winds up the electrode foil 1 on which the electrode layer is formed, and a plurality of rollers 5. Become. And in this Embodiment, the electrode foil 1c in the solidification chamber 8 is arrange | positioned by the roller 5b provided in the solidification chamber 8 from the roller 5c provided in the drying chamber 6 in the diagonally lower side by the side view. And the electrode foil 1d in the drying chamber 6 create a transport system that forms an obtuse angle.

  In other words, in the solidification chamber 8, the virtual line P drawn horizontally with respect to the electrode foil 1d disposed in the drying chamber 6 and the electrode foil 1c disposed in the solidification chamber 8 form an acute angle (θ2). It is a serious arrangement relationship. In other words, the imaginary line P extending in the horizontal direction and the electrode foil 1c are arranged so as to form an acute angle (θ2).

  In other words, the electrode foil 1c arranged in the solidification chamber 8 is arranged at an angle that is not horizontal (an acute angle or an obtuse angle with respect to the horizontal direction).

  As described above, the position of the electrode foil 1c in the solidifying chamber 8 is lower than the position of the electrode foil 1d in the drying chamber 6 and forms an obtuse angle with the electrode foil 1d in the drying chamber 6 by the arrangement of the rollers 5 as described above. As a result, a plurality of transport directions S of the transport system of the electrode foil 1 can be provided. That is, there are a plurality of transport directions S of the transport system of the electrode foil 1 extending from the solidification chamber 8 to the drying chamber 6 in the horizontal direction (S2) and directions other than the horizontal direction (in the present embodiment, the diagonally upward direction (S1)). It can be in (two) directions.

  Accordingly, as in the manufacturing apparatus of the first comparative example shown in FIG. 7, as compared with the case where the transport system of the electrode foil 1 extending from the solidification chamber 80 to the drying chamber 60 is one in the horizontal direction, FIG. In the above-described electrode manufacturing apparatus, the length of the transport system projected from above can be shortened. That is, the length of the transport system projected from above of the electrode foil 1 extending from the solidification chamber 8 to the drying chamber 6 can be shortened, and as a result, the footprint (installation area) of the electrode manufacturing apparatus can be reduced. Can be planned.

  Moreover, in the said electrode manufacturing apparatus of this Embodiment, the electrode foil 1b conveyed to the solidification chamber 8 from the coating part 2 makes an acute angle ((theta) 3) with the electrode foil 1c arrange | positioned in the solidification chamber 8 with a conveyance mechanism. It is arranged to form.

  That is, the arrangement of the rollers 5a provided in the coating unit 2 is such that the electrode foil 1b conveyed from the coating unit 2 to the solidification chamber 8 and the electrode foil 1c disposed in the solidification chamber 8 are acute angles ( The arrangement is such that θ3) is formed.

  Furthermore, the electrode foil 1b conveyed from the coating unit 2 to the solidification chamber 8 is arranged to form an acute angle (θ4) with the electrode foil 1a delivered from the current collecting electrode foil roll 4 by the conveying mechanism. . That is, the electrode foil 1b conveyed from the coating part 2 to the solidification chamber 8 and the electrode foil 1a fed out from the current collecting electrode foil roll 4 are arranged in a side view. The arrangement is such that an acute angle (θ4) is formed.

  Thereby, the electrode foil roll 4 for current collection will be arrange | positioned in the vicinity of both the solidification room | chamber 8 and the drying room | chamber 6, and the said electrode manufacturing apparatus will be made to a horizontal direction and a height direction. However, it is possible to reduce the size.

  In the electrode manufacturing apparatus of the present embodiment, the solidification chamber 8 is provided with a slit nozzle 8a for discharging the solidified liquid 8b, and the electrode material applied on the electrode foil 1 from the slit nozzle 8a is provided. Then, the solidified liquid 8b is supplied.

  Thus, by discharging the solidified liquid 8b from the slit nozzle 8a, the solidified liquid 8b can be applied to the electrode material in a laminar state.

  In addition, a pan (second container) 8 d for collecting the waste liquid (solidified liquid 8 b) 8 c is provided below the lowermost part of the electrode foil 1 c (1 b) disposed in the solidifying chamber 8.

  At that time, in the electrode manufacturing apparatus of the present embodiment, since the electrode foil 1c is disposed obliquely with respect to the horizontal direction in the solidification chamber 8, the applied solidification liquid 8b is carried to the subsequent drying chamber 6. Or can be prevented from spreading.

  That is, since the solidified liquid 8b supplied on the electrode foil 1 flows downward and flows directly below the electrode foil 1c arranged obliquely, the pan 8d does not need to be large, and the electrode foil As long as it has the same width as 1, the depth may be thin.

  That is, since the solidified liquid 8b supplied on the electrode foil 1 flows down directly along the electrode foil 1c, the small pan 8d can be installed without installing the large pan 8d. The electrode manufacturing apparatus can be downsized.

  Next, the manufacturing method of the lithium ion battery in this Embodiment is demonstrated using FIG. First, an electrode material that is a material for forming an electrode layer constituting a positive electrode or a negative electrode of a lithium ion battery is prepared. Such an electrode material is a high-viscosity slurry-like liquid, and is supplied from the collecting electrode foil roll 4 by a coating mechanism (die coater 3 in the present embodiment) installed in the coating unit 2 shown in FIG. It is applied thinly and uniformly on the surface of the electrode foil 1 (1a). That is, an application process is performed in the coating unit 2.

  The electrode material used in the present embodiment includes at least a positive or negative electrode active material powder, and in some cases includes a solid component of a conductive material powder. The electrode material is a binder for binding between powder components or between the powder component and the electrode foil after drying, and includes a binder that is hardly soluble in water and a solidifying material. Furthermore, the electrode material is a solvent for adjusting the above components as a slurry-like high-viscosity liquid paste, and further includes a solvent compatible with water.

  That is, the electrode material includes a positive or negative electrode active material powder, a water-insoluble binder, a solidifying material, and a solvent compatible with water, and in some cases includes a solid component of a conductive material powder. However, it is more preferable that the binder and the solidifying material are combined. Specifically, the electrode material preferably contains at least a positive or negative electrode active material powder, a binder that can be used as a solidifying material, and a solvent.

  Next, the electrode foil 1 (1b) is used by using a transport mechanism (a transport system using a roller 5 in the present embodiment) that transports the electrode foil 1 at a constant speed while in contact with the back surface of the electrode foil 1 coated with the electrode material. ) Is carried into the solidification chamber 8.

  In the solidification chamber 8, a solidification process is performed. Specifically, the electrode material is solidified by contacting (supplying) the solidified liquid 8b to the surface of the electrode material applied on the electrode foil 1. The solidified liquid 8b is pure water or ethanol.

  Here, in the electrode manufacturing apparatus (lithium ion battery manufacturing apparatus) of the present embodiment, the roller 5b provided in the solidification chamber 8 is obliquely below the roller 5c provided in the drying chamber 6 in a side view. Is arranged. Thereby, the conveyance system of the electrode foil 1 which the electrode foil 1c arrange | positioned at the solidification chamber 8 and the electrode foil 1d arrange | positioned at the drying chamber 6 form an obtuse angle ((theta) 1) is created.

  In the solidification chamber 8, the virtual line P drawn horizontally with respect to the electrode foil 1d disposed in the drying chamber 6 and the electrode foil 1c disposed in the solidification chamber 8 form an acute angle (θ2). It is an arrangement relationship.

  As described above, the position of the electrode foil 1c in the solidifying chamber 8 is lower than the position of the electrode foil 1d in the drying chamber 6 and forms an obtuse angle with the electrode foil 1d in the drying chamber 6 by the arrangement of the rollers 5 as described above. As a result, a plurality of transport directions S of the transport system of the electrode foil 1 can be provided. That is, the transport direction S of the transport system of the electrode foil 1 can be set in a plurality of directions, ie, the horizontal direction (S2) and a direction other than the horizontal direction (in the present embodiment, the diagonally upward direction (S1)).

  Application of the solidified liquid 8b to the electrode material is performed by discharging the solidified liquid 8b from the slit nozzle 8a.

  That is, in this solidification step, the electrode foil 1 (1c) in the solidification chamber 8 is below the position of the electrode foil 1 (1d) in the drying chamber 6 and is obtuse with the electrode foil 1 (1d) in the drying chamber 6. The solidified liquid 8b is supplied to the electrode foil 1 from the slit nozzle 8a in a state of being arranged so as to form (θ1).

  Specifically, the electrode material applied to the electrode foil 1 is supplied with the solidified liquid 8b from the slit nozzle 8a to the surface of the electrode material, and the electrode material is brought into contact with the electrode material by bringing the solidified liquid 8b into contact therewith. Solidify. At this time, the solidified liquid 8b is, for example, pure water or ethanol. That is, by bringing the solidified liquid 8b such as pure water into contact with the electrode material applied on the electrode foil 1, the electrode material penetrates into the electrode material while being dissolved in the solvent contained in the electrode material. And if the density | concentration of the water in an electrode material increases, the solubility of a binder (solidification material) will run short, and a binder (solidification material) will precipitate.

  At this time, the active material particles contained in the electrode material are bound together, and the entire electrode material is solidified. Since the solidification process occurs in a time much shorter than the time required for drying and the like, the fluidity inside the electrode material becomes low, and the distribution of various components contained in the electrode material is fixed almost instantaneously. The

  As described above, in the present embodiment, since the electrode material is solidified before the electrode material is dried, a contact-type transport system can be used for transporting the electrode foil 1. In other words, it is not necessary to use a complicated and expensive non-contact conveyance system. Therefore, in the present embodiment, an inexpensive drying chamber 6 using a conveyance system by the roller 5 is employed. This advantage is particularly effective when the electrode materials applied to both surfaces of the electrode foil 1 are collectively dried. However, the use of a non-contact type transport system such as an air floating transport system is not excluded.

  Further, by discharging the solidified liquid 8b from the slit nozzle 8a, the solidified liquid 8b can be applied to the electrode material in a state where the solidified liquid 8b is laminarized in the width direction of the electrode foil 1.

  In the solidification chamber 8, a pan 8d for collecting the waste liquid (solidification liquid 8b) 8c is provided immediately below the lowermost part of the electrode foil 1c (1b). As a result, of the supplied solidification liquid 8b, The waste liquid 8c that flows down below the electrode foil 1c disposed obliquely is collected by the pan 8d.

  Next, the electrode foil 1 is carried into the drying chamber 6 by the conveyance system of the roller 5 (5c) shown in FIG. 1, and a drying process is performed. Specifically, the liquid material in the electrode material is heated and evaporated by a known method such as hot air drying to dry the electrode material, thereby forming the electrode layer.

  Thereafter, the electrode foil roll 7 on which the electrode foil 1 that has undergone the drying process is wound is supplied to the next process. However, when an electrode layer is also formed on the back surface of the electrode foil 1, the above process is also performed on the back surface of the electrode foil 1, and an electrode sheet having electrode layers formed on both surfaces is manufactured. The process proceeds to the next step.

  Note that the drying chamber 6 shown in FIG. 1 has a relatively short conveyance path in the chamber. That is, since the solidification chamber 8 is provided in the front stage of the drying chamber 6, the length of the drying chamber 6 can be shortened. For example, the length of the drying chamber 6 in the present embodiment is about 10 m. .

  In addition, as described above, a positive electrode sheet is formed by forming a positive electrode layer (for example, a conductive material layer such as acetylene black) on the surface of a positive electrode foil (for example, Al (aluminum)). Furthermore, a negative electrode sheet is formed by forming a negative electrode layer (for example, a conductive material layer such as acetylene black) on the surface of a negative electrode foil (for example, Cu (copper)) by the above-described steps.

  Then, a positive electrode sheet and a negative electrode sheet are laminated | stacked through a separator layer, and a laminated body is formed. Although a separator layer can also be formed using a well-known film-like separator, a separator layer can also be integrally formed on the electrode layer of a positive electrode sheet or a negative electrode sheet by the method mentioned later.

  Next, an example of a lithium ion battery manufactured by the method of manufacturing a lithium ion battery of the present embodiment is shown in FIG. In the illustrated lithium ion battery, a laminated body including a positive electrode sheet 10, a negative electrode sheet 11, and a separator 12 as a separator layer is incorporated in a cylindrical container 13. More specifically, the laminate is cut into a predetermined length, wound, and incorporated in the container 13.

  Therefore, in the container 13, the positive electrode sheet 10 on which the positive electrode layer is formed, the separator 12 as the separator layer, and the negative electrode sheet 11 on which the negative electrode layer is formed are repeatedly stacked alternately. In other words, the separator layer is interposed between the adjacent positive electrode sheet 10 and negative electrode sheet 11.

  The container 13 is filled with an electrolytic solution together with the laminate. One end of the container 13 is sealed with a positive electrode terminal 15, and the other end is sealed with a negative electrode terminal 16. The positive electrode sheet 10 is electrically connected to a positive electrode terminal 15 having a gas discharge structure via a positive electrode lead 14 made of a metal film, and the negative electrode sheet 11 is connected to a negative electrode lead (not shown) made of a metal film. Are electrically connected to the negative terminal 16.

  Below, each material which comprises the lithium ion battery in this Embodiment, and each material used when manufacturing a lithium ion battery is demonstrated in detail.

  As the positive electrode active material of the lithium ion battery used in this embodiment, a lithium-containing composite oxide having a spinel structure containing lithium cobaltate or manganese (Mn) can be used. As the positive electrode active material, a composite oxide containing nickel (Ni), cobalt (Co), manganese (Mn), or an olivine type compound typified by olivine type iron phosphate can be used. However, the material used for the positive electrode active material is not limited to these.

Since the lithium-containing composite oxide having a spinel structure containing manganese (Mn) is excellent in thermal stability, a highly safe battery can be configured by forming an electrode sheet containing the lithium-containing composite oxide. Further, as the positive electrode active material, only a lithium-containing composite oxide having a spinel structure containing manganese (Mn) may be used, but another positive electrode active material may be used in combination. Examples of such other positive electrode active materials include Li _{1 + x} MO ₂ (−0.1 <x <0.1, M: Co, Ni, Mn, Al, Mg, Zr, Ti, etc.). And olivine type compounds.

Specific examples of the lithium-containing transition metal oxide having a layered structure, LiCoO ₂ or _{LiNi 1-x Co xy Al y} O 2 (0.1 ≦ x ≦ 0.3,0.01 ≦ y ≦ 0.2 ) Etc. can be used. Further, the lithium-containing transition metal oxide having a layered structure includes an oxide 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.) can be used.

  As the negative electrode active material used in the present embodiment, for example, a graphite material such as natural graphite (flaky graphite), artificial graphite, or expanded graphite can be used. Further, as the negative electrode active material, an easily graphitizable carbonaceous material such as coke obtained by firing pitch can be used. Further, a non-graphitizable carbonaceous material such as amorphous carbon obtained by low-temperature firing of furfuryl alcohol resin (PFA), polyparaphenylene (PPP), phenol resin, or the like may be used as the negative electrode active material. Good. In addition to the carbon material, lithium (Li) or a lithium-containing compound can also be used as the negative electrode active material.

  Examples of the lithium-containing compound include a lithium alloy such as Li—Al, Si (silicon), or an alloy containing an element capable of alloying Sn (tin) with lithium (Li). In addition, an oxide-based material such as Sn oxide or Si oxide can also be used.

  The conductive material used in the present embodiment is used as an electron conduction assistant to be contained in the positive electrode mixture layer, and for example, a carbon material such as carbon black, acetylene black, graphite, carbon fiber, or carbon nanotube is preferable. Among the above carbon materials, it is particularly preferable to use acetylene black from the viewpoint of the amount of addition and conductivity, and the productivity of the positive electrode mixture layer-containing composition (described later). Such a conductive material can be used as a material for the negative electrode mixture layer and may be preferable. Here, the positive electrode or negative electrode mixture layer is the electrode material described above or an electrode layer obtained by solidifying and drying the electrode material.

  In the present embodiment, a binder including a binder component that also serves as a solidifying material can be used. Specifically, the binder preferably contains a binder component for binding the active material and the electron conduction aid. As the 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) or a rubber polymer is preferably used. Two or more of the above polymers may be used in combination. The binder used in the present embodiment is preferably provided in the form of a solution dissolved in a solvent.

  The fluorine-containing monomer group for synthesizing the polyvinylidene fluoride-based polymer includes vinylidene fluoride, or a mixture of vinylidene fluoride and another monomer, and a monomer mixture containing 80% by mass or more of vinylidene fluoride. Can be mentioned. Examples of the other monomer include vinyl fluoride, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether.

  Examples of the rubber-based polymer include styrene butadiene rubber (SBR), ethylene propylene diene rubber, and fluorine rubber.

  The content of the binder in each mixture layer of the positive electrode and the negative electrode is 0.1% by mass or more, more preferably 0.3% by mass or more, and 10% by mass or less, based on the electrode material after drying. More preferably, it is 5 mass% or less. When the content of the binder is too small, not only solidification in the solidification step is insufficient, but the mechanical strength of the mixture layer after drying is insufficient, and the mixture layer may be peeled off from the electrode foil. Moreover, when there is too much content of a binder, there exists a possibility that the quantity of the electrically conductive material in a mixture layer may reduce and battery capacity may become low.

  As the solidifying material used in the present embodiment, the same material as the binder or a mixture of a plurality of materials that can be used as the binder is used. It is also possible to use a component having no performance as a binder and having only a performance as a solidifying material in addition to the binder.

  In addition, for example, an extrusion coater, a reverse roller, a doctor blade, and an applicator can be used as an application mechanism (coating means) for applying an electrode material to the electrode foil 1.

  The electrode foil 1 is not limited to a sheet-like foil. As the material of the electrode foil 1, for example, a pure metal such as aluminum (Al), copper (Cu), stainless steel, or titanium (Ti) or an alloy conductive material can be used. The shape of the electrode foil 1 may be a net shape or a plate shape. The electrode foil 1 may be a punched metal or a foam metal. As thickness of the electrode foil 1, 5-30 micrometers is selected, for example, More preferably, 8-16 micrometers is selected. Moreover, the thickness of the electrode layer formed in one surface of the electrode foil 1 is a thickness after drying, for example, can select 10-300 micrometers, More preferably, it can select 30-150 micrometers.

  In addition, the solvent used in this embodiment has a property of being dissolved in water. As such a solvent, an aprotic polar solvent represented by N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide, propylene carbonate, dimethylformamide, γ-butyrolactone, or a mixture thereof can be selected. .

  Next, the drying process performed in the drying chamber 6 shown in FIG. 1 will be described.

  Although it is possible to use hot air drying for the drying step, the drying step is not limited to this. As a drying means, a heating method of irradiating infrared rays, far infrared rays or other electromagnetic waves may be used. It is also possible to use a dielectric heating method using a high-frequency electric field or an induction heating method using a change in magnetic flux. Furthermore, a contact heating method using a heating roll or a hot plate incorporating a heater may be used, and a heating method combining some of the drying means described above can also be used.

  Hereinafter, each process which comprises the manufacturing method of the lithium ion battery of this Embodiment is demonstrated more concretely.

  As the positive electrode active material, lithium nickel cobalt manganate as a lithium transition metal composite oxide can be selected. 85: 8: 2: 5 by weight ratio of the lithium transition metal composite oxide, graphite powder as a conductive material, acetylene black as a conductive material, and polyvinylidene fluoride (PVDF) as a binder that also serves as a solidifying material. Mix in the ratio Further, N-methyl-2-pyrrolidone (NMP) as a solvent is sequentially added.

  Next, these mixed components are kneaded with a planetary mixer to prepare an electrode material for a positive electrode. This electrode material is a slurry-like liquid, and a binder component as a solidifying material is dissolved in NMP in the electrode material. The viscosity of the electrode material measured with a rotational viscometer is about 10 Pa · S.

  The electrode material thus kneaded is applied onto an aluminum foil (positive electrode current collector, electrode foil 1) having a thickness of 20 μm with an applicator so as to have a thickness of 100 μm. The above process is an application | coating process which apply | coats the electrode material containing the solvent and water-soluble binder which are compatible with water on the surface of the electrode foil 1. FIG.

  Next, the electrode material is solidified by passing the aluminum foil coated with the electrode material through the solidification chamber 8 shown in FIG. The solidification phenomenon is a phenomenon in which the concentration of NMP, which is a solvent in the electrode material, is reduced by water, so that the binder in the electrode material is insolubilized and precipitates, and the positive electrode agent particles are bound. Since the electrode material solidified in this way loses fluidity and adhesiveness and is held on the aluminum foil, it can sufficiently withstand roller conveyance in which a roller is brought into contact with the surface of the electrode material.

  The above process is a solidification process for solidifying the electrode material.

  Next, the electrode material solidified by the solidification step is dried at a temperature of 120 ° C. for 10 minutes in a warm air drying furnace, and water in the electrode material and a small amount of remaining NMP are removed by evaporation to obtain an aluminum foil ( A positive electrode sheet in which a positive electrode layer is formed on the electrode foil 1) is formed. The above process is a drying process for drying the electrode material.

  Here, as a second comparative example for the present embodiment, a method for manufacturing a lithium ion battery when the solidification step is not performed before the drying step will be described below. In the manufacturing method of the lithium ion battery of the second comparative example, an electrode material having the same components as in the present embodiment is applied onto an aluminum foil, and the applied electrode material is heated at 120 ° C. for 10 minutes in a warm air drying furnace. Dry to evaporate and remove NMP in the electrode material. Thereby, the positive electrode sheet in which the electrode layer for positive electrodes was formed on the aluminum foil is formed. Thus, in the second comparative example, an electrode for a lithium ion battery having the same composition as that of the present embodiment is manufactured by a manufacturing method in which the solidification step of the present embodiment is omitted.

  FIG. 3 shows a comparison of various characteristics of the electrode layer obtained by the manufacturing method of the present embodiment and the manufacturing method of the second comparative example described above. As described above, in the manufacturing method of the present embodiment including the solidification step, the electrode material is solidified before the drying step. On the other hand, in the drying step in the manufacturing method of the second comparative example, the liquid electrode material is dried in a hot air drying furnace. Therefore, in the manufacturing method of the present embodiment, it is possible to transport a roller or the like in contact with the surface of the electrode material in the drying step, whereas in the manufacturing method of the second comparative example, such a transport method. It is impossible in principle to use.

  Moreover, the difference between the manufacturing method of this Embodiment and the manufacturing method of a 2nd comparative example appears notably in the composition distribution etc. of an electrode layer. For the dried electrode material (electrode layer), a scanning electron microscope (SEM) and an energy dispersive X-ray spectroscopy (EDX) are used as analysis techniques. Thereby, the composition distribution in the thickness direction of the cross section of the electrode layer can be measured. When the concentration of the binder component in the thickness direction of the electrode layer measured by this method is more than twice the ratio between the surface and the bottom surface (the surface in contact with the aluminum foil), “large distribution”, twice The smaller case is defined as “small distribution”. In the comparison of distribution, the electrode layer made by the manufacturing method of the present embodiment has a small distribution, and the electrode layer made by the manufacturing method of the second comparative example has a large distribution, and a significant difference is recognized.

  Moreover, the following differences are recognized about distribution of a binder component. In the manufacturing method of the second comparative example in FIG. 3 in which the electrode material is liquid when the electrode material is dried, a large concentration distribution is generated due to mass transfer of components such as a binder in the electrode material, that is, convection or diffusion. It is estimated that On the other hand, in the manufacturing method of the present embodiment, since the electrode material is solidified in the solidification step and the components of the electrode material are also fixed, the movement of components during drying is suppressed and the concentration distribution becomes small. .

  Further, the distribution of the positive electrode active material and the conductive material, which are solid particles in the layer obtained from the observation of the electrode layer, also becomes large in the electrode layer made by the manufacturing method of the second comparative example in FIG. On the other hand, the distribution is small in the electrode layer made by the manufacturing method of the present embodiment. Thereby, it is recognized that a uniform electrode layer can be obtained.

  According to the lithium ion battery manufacturing apparatus and the manufacturing method of the present embodiment, the electrode foil 1c in the solidification chamber 8 is positioned from the position of the electrode foil 1d in the drying chamber 6 due to the arrangement of the plurality of rollers 5 constituting the transport system. Is also arranged on the lower side. Furthermore, the electrode foil 1c in the solidification chamber 8 is disposed so as to form an obtuse angle (θ1) with the electrode foil 1d in the drying chamber 6.

  As a result, the transport system of the electrode foil 1 can be deflected (changed) from the horizontal direction downward.

  That is, in the transport system of the electrode foil 1 extending from the solidification chamber 8 to the drying chamber 6, a plurality of transport directions S of the transport system can be provided. In the present embodiment, the horizontal direction (S2) and a direction other than the horizontal direction (obliquely upward direction (S1)) can be used.

  Accordingly, as in the manufacturing apparatus of the first comparative example of FIG. 7, the lithium ion battery according to the present embodiment is compared with the case where the conveying direction of the electrode foil 1 extending from the solidification chamber 80 to the drying chamber 60 is one horizontal direction. In this manufacturing apparatus, the length of the transport system (transport mechanism) projected from above can be shortened. In other words, it is possible to reduce the area in plan view required for the transport system of the electrode foil 1. That is, it is possible to reduce the footprint (installation area) of the electrode manufacturing apparatus constituting the lithium ion battery manufacturing apparatus.

  As a result, the footprint of the lithium ion battery manufacturing apparatus can be reduced, and the lithium ion battery manufacturing apparatus can be downsized.

  In addition, since the lithium ion battery manufacturing apparatus can be downsized, the manufacturing cost of the manufacturing apparatus can be reduced.

  Moreover, in the manufacturing apparatus (electrode manufacturing apparatus) of the lithium ion battery according to the present embodiment, the arrangement of the rollers 5a of the coating unit 2 includes the electrode foil 1b conveyed from the coating unit 2 to the solidification chamber 8, and the solidification chamber. The electrode foil 1c arranged at 8 forms an acute angle (θ3) in a side view.

  Furthermore, the electrode foil 1b conveyed from the coating part 2 to the solidification chamber 8 and the electrode foil 1a fed out from the current collecting electrode foil roll 4 are arranged in a side view. The arrangement is such that an acute angle (θ4) is formed.

  Thereby, the electrode foil roll 4 for current collection will be arrange | positioned in the very vicinity of both the solidification room | chamber 8 and the drying room | chamber 6, and the manufacturing apparatus of a lithium ion battery will be high also in a horizontal direction. The size can also be reduced with respect to the direction.

  A small pan 8d for collecting the waste liquid 8c is provided below the lowermost portion of the electrode foil 1c (1b) disposed in the solidification chamber 8. This is because, in the solidification chamber 8, the electrode foil 1c is disposed obliquely with respect to the horizontal direction, so that the applied solidification liquid 8b can be prevented from being conveyed to the subsequent drying chamber 6 or diffusing. That is, since the solidified liquid 8b applied on the electrode material does not flow down and scatter immediately below the electrode foil 1c arranged obliquely, it is possible to reduce the size without installing a large pan 8d for preventing diffusion. The waste liquid 8c can be collected by installing the pan 8d.

  As a result, the lithium ion battery manufacturing apparatus (electrode manufacturing apparatus) can be downsized.

  Further, in the lithium ion battery manufacturing apparatus of the present embodiment, the solidification chamber 8 is provided with a slit nozzle 8a for discharging the solidification liquid 8b, and the electrode material applied on the electrode foil 1 from the slit nozzle 8a. Is supplied with solidified liquid 8b. By discharging the solidified liquid 8b from the slit nozzle 8a, the solidified liquid 8b permeates into the electrode material, and the binder is deposited.

  At this time, by discharging the solidified liquid 8b from the slit nozzle 8a, the solidified liquid 8b can be uniformly injected in a laminar state and applied to the electrode material.

  Thereby, since the solidified liquid 8b is uniformly hold | maintained on an electrode material, the uniformity of the solidified liquid 8b is improved, As a result, the uniformity of the binder to precipitate can also be improved. Furthermore, drying unevenness when the drying process is performed in the drying chamber 6 can be reduced.

  Further, by using the slit nozzle 8a, it is possible to uniformly inject the solidified liquid 8b in a laminar state, and therefore it is possible to easily control the recovery of the waste liquid 8c.

  Furthermore, since the solidified liquid 8b flows in a laminarized state by using the slit nozzle 8a, the solidified liquid 8b does not scatter when the excess solidified liquid 8b is recovered. Therefore, the pan 8d for collecting the waste liquid 8c can be collected in a minimum region without considering the scattering of the waste liquid 8c, and the apparatus configuration does not have to be complicated. As a result, the maintainability of the lithium ion battery manufacturing apparatus can be improved.

  Further, by using the slit nozzle 8a, it is possible to prevent the solidified liquid 8b from being scattered when the solidified liquid 8b is applied. Therefore, the solidification chamber chamber for preventing the solidified liquid from scattering and adhering to the mechanism portion. There is no need for installation.

  As a result, it is not necessary to complicate the apparatus configuration as described above.

  Moreover, the application amount of the solidified liquid 8b can be made constant by using the slit nozzle 8a. When the object to be coated is a member having a predetermined width as in the electrode foil 1 of the present embodiment, for example, a slit is formed in comparison with a nozzle that has a circular tip and is coated in a dot shape. The nozzle 8a can apply in a certain amount with respect to the width direction. As a result, the uniformity of application can be improved.

  Furthermore, since the uniformity of application of the solidified liquid 8b can be improved, the permeability of the solidified liquid 8b can also be improved.

  As a result, the quality of the lithium ion battery shown in FIG. 2 can be improved.

  Further, according to the manufacturing method of the present embodiment, the composition and the layer thickness of the electrode material can be stably maintained by introducing the solidification step before the drying step.

  Further, in the manufacturing method of the present embodiment in which the solidification step is performed prior to the drying step, the drying step is performed after eliminating the possibility of fluctuations in the composition and film thickness of the electrode material. Is possible. Therefore, by manufacturing a lithium ion battery using the manufacturing apparatus of this embodiment, the quality of the electrode layer can be stabilized, the drying equipment can be downsized, and the manufacturing cost of the lithium ion battery can be reduced. .

  In addition, it is possible to use a contact-type roller conveyance system that comes into contact with the coating film for conveying the electrode foil holding the electrode material before or during the drying process. It is also possible to obtain an effect that the degree of freedom in selecting the device configuration is improved.

  Moreover, in this Embodiment, since a drying process is performed after losing the fluidity | liquidity of an electrode material by a solidification process, a binder does not segregate on the surface of an electrode material in a drying process. Thereby, it can prevent that the adhesiveness of an electrode layer and electrode foil falls.

  In addition, the solidification process in the manufacturing method of this Embodiment can also be used for manufacture of not only a positive electrode sheet but a negative electrode sheet, and can also be used for formation of the separator 12 (refer FIG. 2) as a separator layer.

  The manufacturing method of a separator has a process substantially the same as the process of forming a positive electrode sheet and a negative electrode sheet. Specifically, a separator can be formed by applying a paste-like separator material on a base material (foil), followed by solidification and drying.

  In a specific separator manufacturing process, for example, a base material roll is set in a manufacturing apparatus similar to the manufacturing apparatus shown in FIG. 1 instead of the collecting electrode foil roll 4. Thereafter, as in the electrode layer forming step, a paste-like separator material is applied to the surface of the base material transported by the transport mechanism at the coating portion.

  Next, the base material coated with the separator material is carried into the solidification chamber, and the binder contained in the separator material is precipitated to solidify the separator material. Thereafter, the base material holding the solidified separator material is carried into a drying chamber, and the separator material is dried. Through the above steps, a separator having a separator layer formed on a substrate can be produced.

  The separator material, which is a material for forming the separator layer, is a mixture of silica (silicon oxide), alumina (aluminum oxide) or polyethylene, the above-described binder, and a solvent (for example, N-methyl-2-pyrrolidone (NMP)). A mixed paste can be used.

  The separator (separator layer) manufactured as described above is made of, for example, a porous polypropylene film, and is interposed between the positive electrode sheet and the negative electrode sheet in the completed lithium ion battery, and the bipolar electrode active of adjacent electrodes. Contact between substances can be prevented. Further, the electrolytic solution is held in the pores in the separator layer, and a passage for ion conduction between the electrodes is formed.

  As in this embodiment, the separator material is solidified before the drying step, so that the composition of the separator material is stabilized, the drying device is simplified, the throughput is improved, and the separator is manufactured while reducing the manufacturing cost. Quality can be maintained.

(First modification)
FIG. 4 is a schematic diagram showing the structure of an electrode manufacturing apparatus constituting the lithium ion battery manufacturing apparatus of the first modification in the embodiment of the present invention.

  In the first modified example, in the electrode manufacturing apparatus, the air nozzle 8f that blows air 8e around the lowermost part of the electrode foil 1c (or the electrode foil 1b) disposed in the solidifying chamber 8 or around the lowermost part is solidified. It is provided in the chamber 8.

  Thus, in the solidification process, air 8e is blown to the lowermost part of the electrode foil 1c (or the electrode foil 1b) disposed in the solidification chamber 8 or around the electrode foil 1c, so that the electrode foil is formed at the lowermost part of the electrode foil 1c or the surrounding area. The solidified liquid 8b adhering to 1c and the electrode foil 1b can be removed.

  As a result, it is possible to prevent the solidified liquid 8b from being carried to the coating part 2 provided in the previous stage of the solidification chamber 8 in the transport direction S of the electrode foil 1.

(Second modification)
FIG. 5 is a schematic diagram showing the structure of an electrode manufacturing apparatus that constitutes a lithium ion battery manufacturing apparatus according to a second modification of the embodiment of the present invention.

  The second modification is provided with a tank (first container) 9 that is connected (communicated) with the slit nozzle 8a and contains the solidified liquid 8b in the electrode manufacturing apparatus, and the solidified liquid 8b. Is supplied from the tank 9 to the slit nozzle 8a. Further, a pump 17 for adjusting the discharge amount of the solidified liquid 8b discharged from the slit nozzle 8a is provided between the slit nozzle 8a and the tank 9, that is, a pipe connecting the slit nozzle 8a and the tank 9.

  In addition, about the application quantity (discharge amount) of the solidification liquid 8b, it depends on the conveyance speed of the electrode foil 1. FIG. That is, when the conveying speed is fast, a large amount of coating is required, and when the conveying speed is slow, the binder is deposited with a small amount of coating. Therefore, it is necessary to cope with the change in the conveyance speed depending on the viscosity, film thickness, etc. of the electrode coating liquid (electrode material). That is, it is preferable that the application amount of the solidified liquid 8b can be easily adjusted.

  Therefore, the pump 17 is provided in the pipe connecting the slit nozzle 8a and the tank 9, so that the application amount (discharge amount) of the solidified liquid 8b discharged from the slit nozzle 8a can be easily adjusted by the pump 17. Can do.

  As a result, even when it is necessary to vary the conveying speed of the electrode foil 1 depending on the viscosity or film thickness of the electrode coating liquid (electrode material), the application of the solidified liquid 8b discharged from the slit nozzle 8a by the pump 17 The amount (discharge amount) can be adjusted. That is, it is possible to easily cope with a change in the conveyance speed of the electrode foil 1.

(Third Modification)
FIG. 6 is a schematic diagram showing the structure of an electrode manufacturing apparatus that constitutes a lithium ion battery manufacturing apparatus according to a third modification of the embodiment of the present invention.

  In the third modified example, the slit nozzle 8a provided in the electrode manufacturing apparatus is made of a block material of each of an upstream die 8aa and a downstream die 8ab that are a pair of dies. Further, the slit nozzle 8a adjusts the gap (gap amount) 18 between the tip portions of the pair of upstream die 8aa and downstream die 8ab, thereby applying the application amount (discharge) of the solidified liquid 8b discharged from the slit nozzle 8a. This is a nozzle whose amount can be adjusted.

  That is, as a method of varying the application amount (discharge amount) of the solidifying liquid 8b, even when the supply amount of the solidifying liquid 8b from the tank 9 shown in FIG. By adjusting, the application amount (discharge amount) of the discharged solidified liquid 8b can be adjusted.

  The size of the gap 18 at the tip of the slit nozzle 8a composed of the upstream die 8aa and the downstream die 8ab is, for example, a shim (plate material) 8g disposed between the upstream die 8aa and the downstream die 8ab. It can be adjusted by changing the thickness.

  Although the invention made by the present inventors has been specifically described based on the embodiment, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, the installation location and the number of installation of the rollers 5 in the transport mechanism having a plurality of rollers 5 are not limited to the structure shown in FIG. That is, it is only necessary that the electrode foil 1c of the solidification chamber 8 is disposed below the position of the electrode foil 1d of the drying chamber 6 and forms an obtuse angle with the electrode foil 1d of the drying chamber 6, The installation location and the number of installation of the roller 5 can be variously changed.

1, 1a, 1b, 1c, 1d Electrode foil 2 Coating part (application part)
3 Die coater 4 Electrode foil roll for current collection 5 Roller (conveyance mechanism)
5a, 5b, 5c Roller 6 Drying room (drying section)
7 Electrode foil roll 8 Solidification chamber (solidification part)
8a Slit nozzle 8aa Upstream die 8ab Downstream die 8b Solidified liquid 8c Waste liquid 8d Pan (second container)
8e Air 8f Air nozzle 8g Shim 9 Tank (first container)
DESCRIPTION OF SYMBOLS 10 Positive electrode sheet 11 Negative electrode sheet 12 Separator 13 Container 14 Positive electrode lead 15 Positive electrode terminal 16 Negative electrode terminal 17 Pump 18 Gap 20 Coating part 30 Die coater 40 Electrode foil roll for current collection 50 Roller conveyance system 60 Drying chamber 70 Electrode foil roll 80 Solidification Chamber 80a Nozzle 80b Pan

Claims (12)

A lithium ion battery manufacturing apparatus comprising a laminate in which a positive electrode sheet on which a positive electrode layer is formed and a negative electrode sheet on which a negative electrode layer is formed are alternately laminated via a separator layer,
A transport mechanism for transporting the electrode foil;
An application part for applying an electrode material containing a solvent compatible with water and a binder hardly soluble in water on the electrode foil;
A solidification section for supplying a solidification liquid to the surface of the electrode material applied on the electrode foil;
A drying section for drying the electrode material to form the electrode layer;
Have
Lithium ions are arranged such that the transport mechanism causes the electrode foil in the solidification part to be lower than the position of the electrode foil in the drying part and to form an obtuse angle with the electrode foil in the drying part. Battery manufacturing equipment. In the manufacturing apparatus of the lithium ion battery according to claim 1,
An apparatus for manufacturing a lithium ion battery, wherein the solidifying portion is provided with a slit nozzle for discharging the solidified liquid. In the manufacturing apparatus of the lithium ion battery according to claim 1 or 2,
An apparatus for manufacturing a lithium ion battery, wherein an air nozzle that blows air on a lowermost part of the electrode foil disposed in the solidification part is provided in the solidification part. In the manufacturing apparatus of the lithium ion battery according to claim 2 or 3,
A first container connected to the slit nozzle and containing the solidified liquid is provided, and an amount of the solidified liquid discharged from the slit nozzle is adjusted between the slit nozzle and the first container. An apparatus for producing a lithium ion battery, provided with a pump for performing the operation. In the manufacturing apparatus of the lithium ion battery according to any one of claims 2 to 4,
The slit nozzle includes a pair of dies, and is a nozzle capable of adjusting a discharge amount of the solidified liquid discharged from the slit nozzle by adjusting a gap amount between tip portions of the pair of dies. Battery manufacturing equipment. In the manufacturing apparatus of the lithium ion battery according to claim 1,
The apparatus for manufacturing a lithium ion battery, wherein the electrode foil transported from the coating unit to the solidification unit by the transport mechanism is disposed so as to form an acute angle with the electrode foil disposed in the solidification unit. In the manufacturing apparatus of the lithium ion battery according to claim 1,
An apparatus for manufacturing a lithium ion battery, wherein a second container for recovering a waste liquid is provided below a lowermost part of the electrode foil disposed in the solidification unit. A method for producing a lithium ion battery comprising a laminate in which a positive electrode sheet on which a positive electrode layer is formed and a negative electrode sheet on which a negative electrode layer is formed are alternately laminated via a separator layer,
An application step of applying an electrode material containing a solvent compatible with water and a water-insoluble binder on the electrode foil;
A solidification step of supplying a solidified liquid to the surface of the electrode material applied on the electrode foil;
A drying step of drying the electrode material supplied with the solidified liquid to form the electrode layer;
Have
In the solidification step, the solidification is performed in a state where the electrode foil is disposed below the position of the electrode foil disposed in the drying step and to form an obtuse angle with the electrode foil in the drying step. A method for manufacturing a lithium ion battery, wherein the liquid is supplied. In the manufacturing method of the lithium ion battery according to claim 8,
A method of manufacturing a lithium ion battery, wherein in the solidification step, the solidification liquid is supplied from a slit nozzle to the surface of the electrode material. In the manufacturing method of the lithium ion battery of Claim 8 or 9,
A method for manufacturing a lithium ion battery, wherein air is blown to a lowermost portion of the electrode foil disposed in the solidification portion in the solidification step. In the manufacturing method of the lithium ion battery according to claim 9 or 10,
The manufacturing method of a lithium ion battery which adjusts the discharge amount of the said solidification liquid discharged from the said slit nozzle with the pump connected with the said slit nozzle. In the manufacturing method of the lithium ion battery in any one of Claim 9 to 11,
The manufacturing method of a lithium ion battery which adjusts the discharge amount of the said solidification liquid discharged from the said slit nozzle by adjusting the clearance gap amount of the front-end | tip part of the said slit nozzle.

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