WO2015156213A1

WO2015156213A1 - Lithium ion secondary battery, method for manufacturing same and apparatus for manufacturing same

Info

Publication number: WO2015156213A1
Application number: PCT/JP2015/060524
Authority: WO
Inventors: 高原　洋一; 正志西亀; 千恵美窪田; 栄作二ノ宮; 正興松岡; 恭一森; 藤井　武
Original assignee: 株式会社日立ハイテクノロジーズ
Priority date: 2014-04-09
Filing date: 2015-04-02
Publication date: 2015-10-15
Also published as: CN106063020A; CN106063020B; JPWO2015156213A1; JP6307594B2

Abstract

Conventional lithium ion secondary batteries have a problem such that in cases where an insulating material, which forms a separator, is applied onto a coated electrode of a lithium ion secondary battery, the coverage by the insulating material decreases in the edge portion of the electrode layer, thereby increasing the risk of defects due to short circuit. In order to solve the above-described problem, an electrode material and a first insulating material are applied onto an electrode substrate that is fed at a predetermined speed, said first insulating material being applied to portions adjacent to both sides of the electrode material in a direction perpendicular to the feeding direction of the electrode substrate; a second insulating material is applied onto the surfaces of the applied electrode material and first insulating material; and the applied electrode material and first and second insulating materials are dried and affixed according to the present invention. Consequently, the coverage of the edge portion of the electrode layer, which is formed of the electrode material, by the insulating layer is increased, so that short circuit defects can be reduced even in cases where the electrode layer is thick.

Description

Lithium ion secondary battery and method and apparatus for manufacturing the same

The present invention relates to a lithium ion secondary battery and a manufacturing method and manufacturing apparatus thereof, and in particular, a positive electrode, a negative electrode, and a lithium ion secondary battery configured by coating a separator that electrically separates the positive electrode and the negative electrode, and a manufacturing method thereof It relates to a manufacturing apparatus.

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 these, lithium ion secondary batteries that have high energy density, long cycle life, low self-discharge property, and high operating voltage are attracting attention. Lithium ion secondary batteries have the advantages described above, and are therefore widely used in portable electronic devices such as digital cameras, notebook personal computers, and mobile phones. 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, 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 a power source are in progress. . Lithium ion secondary batteries have attracted attention as power sources for such electric vehicles and hybrid vehicles. However, since the lithium ion secondary battery has a high operating voltage and high energy density, sufficient countermeasures against abnormal heat generation due to an internal short circuit or an external short circuit are required.

The lithium ion secondary battery is a kind of non-aqueous electrolyte secondary battery, as shown in FIG. 10 showing its operating principle, and is a secondary battery in which lithium ions in the electrolyte solution are responsible for electrical conduction. Lithium metal oxide is used for the positive electrode material (active material), carbon material such as graphite is used for the negative electrode material (active material), and an organic solvent such as ethylene carbonate and lithium hexafluorophosphate (LiPF6) are used for the electrolyte. It is the mainstream to use lithium salt. In the battery, lithium ions exit from the positive electrode and enter the negative electrode during charging, and conversely during discharge, lithium ions exit from the negative electrode and enter the positive electrode. The structure of the lithium ion secondary battery includes, for example, a positive electrode plate coated with a positive electrode material, a negative electrode plate coated with a negative electrode material, and a separator such as a polymer film that prevents contact between the positive electrode plate and the negative electrode plate. The electrode winding body is provided. In the lithium ion secondary battery, the electrode winding body is inserted into the outer can and the electrolyte is injected into the outer can. That is, in a lithium ion secondary battery, a positive electrode plate coated with a positive electrode material on a metal foil and a negative electrode plate coated with a negative electrode material on a metal foil are formed in a band shape, and the positive electrode plate and the negative electrode plate formed in a band shape The electrode winding body is formed by winding in a spiral shape through the separator so that the electrode does not directly contact.

Japanese Patent Application Laid-Open No. 2003-054991 (Patent Document 1) discloses that a positive electrode film and a negative electrode film are separately formed, a separator film is bonded to the negative electrode film, and the positive electrode film is applied to the negative electrode film with a separator. In the conventional electrode manufacturing method in which the electrode winding body is formed by laminating the electrode, there are many steps, and the solution-like electric field substance is uniformly injected into the current collector in which a plurality of the electrode winding bodies are stacked. A technique for improving the point that is very difficult and many defective products are generated is disclosed. That is, in Patent Document 1, a positive electrode material-containing solution and an electrolytic and insulating substance-containing solution are applied to both surfaces of a positive electrode sheet using a die coater having a solution discharge slit, and a heating process is performed. A positive electrode sheet is formed, and similarly, a negative electrode substance-containing solution and an electrolytic and insulating substance-containing solution are applied to both sides of the negative electrode sheet using a die coater, followed by a heating step. The secondary battery manufacturing method and the secondary battery manufacturing apparatus which form an electrode and laminate | stack both electrode sheet-like objects and form an electrode winding body are disclosed.

JP 2003-054991 A

In the application of the electrode material of the lithium ion secondary battery, as in Patent Document 1, the electrode material of the positive electrode or the negative electrode is applied on the surface of the carrier material, and then the insulating material that becomes the separator is applied, thereby improving the production efficiency. The manufacturing apparatus can be made more compact. However, it is not considered that the coverage of the insulating layer due to the coating step at the edge portion of the electrode layer decreases as the electrode layer made of the electrode material becomes thicker.

That is, as the electrode layer becomes thicker, when the positive electrode or negative electrode electrode material is applied to the carrier material surface and the separator insulating material is applied, the air flow due to the coating step at the edge of the electrode layer The coverage decreases due to the entrainment. As a result, there is a problem that insulation at the periphery of the electrode layer cannot be performed and the risk of short circuit failure is increased.

Therefore, an object of the present invention is to provide a lithium ion secondary battery that can ensure the coverage of the insulating layer at the edge portion of the electrode layer, a manufacturing method thereof, and a manufacturing apparatus thereof.

In order to solve the above problems, for example, the configuration described in the claims is adopted. The present invention includes a plurality of means for solving the above-described problems. For example, a lithium ion secondary battery including a positive electrode, a negative electrode, and a separator that electrically separates the positive electrode and the negative electrode is provided. In the manufacturing method, the first insulating material is applied to the electrode substrate supplied at a predetermined speed, on both sides of the electrode material and the electrode material in the direction perpendicular to the supply direction of the electrode substrate. The second insulating material is applied to the surface of the electrode material and the first insulating material, and the applied electrode material and the first and second insulating materials are dried and fixed. The electrode sheet which comprises and the 1st, 2nd insulating material comprises a separator is manufactured.

According to the present invention, when an electrode sheet manufacturing method in which an electrode material and an insulating material are applied on a surface of an electrode substrate and applied at the same time to be dried and fixed, the insulating layer at the edge portion of the electrode layer is used. Since the coverage ratio is improved, short-circuit defects can be reduced even when the electrode layer is thick.

It is a figure which shows typically the specific process until a lithium ion secondary battery is manufactured. It is a block diagram of the manufacturing process of the single side | surface of the positive electrode sheet of a lithium ion secondary battery. It is a figure explaining the gap of the nozzle which coats an insulating material, an electrode layer, and an electrode substrate. It is a figure which shows the electrode cross section when the electrode layer by a prior art is thickened. 1 is a configuration diagram of a method for producing a positive electrode sheet of a lithium ion secondary battery in Example 1. FIG. It is a figure explaining the die-coater in Example 1. FIG. 3 is a diagram illustrating a cross section of an electrode of a battery according to Example 1. 6 is a configuration diagram of a method for producing a positive electrode sheet of a lithium ion secondary battery in Example 2. FIG. It is a figure explaining the die-coater in Example 2. FIG. It is a figure explaining the principle of operation of a lithium ion secondary battery.

First, a specific process until a lithium ion secondary battery according to the present invention is manufactured will be described.

FIG. 1 is a diagram schematically showing the process. As shown in FIG. 1, the manufacturing process of a lithium ion secondary battery includes a positive electrode sheet manufacturing process, a negative electrode sheet manufacturing process, a battery cell assembly process, and a battery module assembly process.

In the positive electrode sheet manufacturing process, first, a slurry material (positive electrode material) is prepared by kneading and preparing various materials as raw materials for the positive electrode material (kneading / mixing). Then, after applying the slurry material to the film-like metal foil and drying (coating), the metal foil coated with the slurry material is subjected to processing such as compression and cutting (processing), and the film-like positive electrode sheet Manufacturing.

On the other hand, the negative electrode sheet manufacturing process is different from the positive electrode sheet manufacturing process in various materials used as raw materials, but the procedure until the negative electrode sheet is manufactured is the same.

Thereafter, in the battery cell assembly process, a positive electrode and a negative electrode having a size necessary for the battery cell are cut out from the film-like positive electrode sheet and negative electrode sheet in a process called winding, and the positive electrode sheet and the negative electrode are cut out. A separator having a size necessary for the battery cell is cut out from the film-like separator material for separating the electrode sheet, and the positive electrode and the negative electrode are overlapped with each other with the cut-out separator interposed therebetween (winding). Then, a group of electrode pairs of the positive electrode, the negative electrode, and the separator assembled together is assembled and welded. Thereafter, the group of welded electrode pairs is placed in a battery can into which an electrolytic solution has been injected (injected), and then the battery can is completely sealed (sealed) to form a battery cell. The battery cell inspection step repeatedly charges and discharges (charges and discharges) the cells of the lithium ion secondary battery created in the cell assembly step, and checks the performance and reliability of the battery cell (for example, the capacity and voltage of the battery cell). (Inspection of current and voltage during charging or discharging) (single cell inspection). Thereby, a battery cell is completed and a battery cell assembly process is complete | finished (single cell).

Next, in the battery module assembly process, a plurality of battery cells are combined in series to form a battery module, and a charge / discharge control controller is connected to form a battery system (module assembly). Thereafter, in the module inspection process, the battery module assembled in the module assembly process is inspected for performance and reliability (for example, inspection of the capacity and voltage of the battery module, current and voltage during charging or discharging) (module inspection). ). Thereby, a battery module is completed (battery module).

This invention relates to the manufacturing method and manufacturing apparatus which concern on the coating process in the said positive electrode sheet manufacturing process and the said negative electrode sheet manufacturing process, and the battery manufactured by it.

Next, a positive electrode sheet or negative electrode sheet disclosed in Patent Document 1, which is a premise of the present invention, is continuously coated with an electrode material, electrolysis, and an insulating material, and then dried and fixed. A series of manufacturing steps to be performed will be described with reference to the drawings. In Patent Document 1, an electrode material, electrolysis, and an insulating material are applied on both surfaces of a carrier material (positive electrode sheet or negative electrode sheet). For simplicity, as a comparative example of this example, FIG. 2 shows a configuration diagram of a manufacturing process example in which an electrode material, electrolysis, and an insulating material are applied to one side of a carrier material.

FIG. 2 is a configuration diagram of a manufacturing process for manufacturing one side of the positive electrode sheet. The positive electrode substrate 1 is fed from a positive substrate feeding roll 2 and coated with a positive electrode material 5 supplied from a die coater 4 facing the roller 3, and then insulated from a die coater 7 at a position facing the roller 6. Material 8 is applied. And it is dried by passing the drying furnace 9, and is wound up by the winding roll 11 via the roller 10, and a positive electrode sheet is manufactured.

As described above, after coating the slurry-like positive electrode material and the insulating material in layers, both coating layers can be dried and fixed simultaneously through a heating and drying process in a drying furnace, which is efficient. However, there is a problem when the electrode layer is thickened. This will be described below.

FIG. 3 is a diagram for explaining a gap between a nozzle for coating an insulating material, an electrode layer, and an electrode substrate. In FIG. 3, reference numeral 12 denotes an electrode layer, which shows a cross section of the electrode layer before the insulating material is applied, as viewed from the supply direction of the electrode substrate 14 (positive electrode substrate 1) of the roller 6. When the electrode layer is thickened by applying the electrode material, a gap 13 between the electrode layer 12 and the die coater 7 that coats the insulating material, and a gap 15 between the electrode substrate 14 and the die coater 7 that coats the insulating material. And the air is entrained at the edge part of the electrode layer (the left and right side parts of the electrode layer 12 in the figure), the coating film of the insulating layer is drained, the coverage is reduced, and the insulation is insufficient. Become.

FIG. 4 shows a cross section of the electrode when the electrode layer is thickened according to the prior art. In FIG. 4, the insulating layer 16 is formed by applying an insulating material on the electrode layer 12, but there is no description in Patent Document 1, but at the same time, the width of the electrode layer 12 (of the electrode substrate 14). It is desirable that the insulating layer 16 is also formed on the edge portions of the electrode layer 12 (both left and right portions of the electrode layer 12 in the figure) by applying the insulating material wider than the direction orthogonal to the supply direction. However, in the edge portion of the electrode layer 12, air entrainment occurs when the insulating material is applied, and the defective insulation portion 17 is generated. This varies depending on the composition of the insulating material, but occurs when the electrode layer becomes 50 μm or more. When a battery is manufactured in this state, a short circuit is likely to occur at the defective insulation portion 17.

Therefore, in order to solve these problems, the implementation of the present invention can improve the coverage of the insulating layer at the edge portion of the electrode layer even when the electrode layer is thick due to the increase in capacity and cost of the lithium ion secondary battery Examples will be described below with reference to the drawings. Hereinafter, the positive electrode and the negative electrode are collectively referred to as electrodes.

FIG. 5 is a configuration diagram of the manufacturing process of the positive electrode sheet of the lithium ion secondary battery of this example. In FIG. 5, the positive electrode substrate 1 is fed at a predetermined speed from a positive electrode substrate feed roll 2 which is an electrode substrate feed mechanism, and is coated with a positive electrode material 5 and a first insulating material 19 supplied from a die coater 18 facing the roller 3. It is crafted.

FIG. 6 shows the die coater 18 of this embodiment. In FIG. 6, the positive electrode material 5 is discharged from the slit 24, and the first insulating material 19 is discharged from the slit 25 and the slit 26 provided on both sides of the slit 24.

Next, in FIG. 5, the second insulating material 21 is supplied from the die coater 20 facing the roller 6 downstream thereof. The second insulating material 21 contains a component for precipitating the binder component of the surface layer of the electrode material, and by applying it, the binder of the surface layer of the electrode material is precipitated, so that the electrode material The active material is fixed, and the active material of the electrode layer cannot be mixed into the insulating material. Then, the active material in the electrode is fixed by spraying the spray liquid 23 containing the component for precipitating the binder of the electrode material from the spray nozzle 22, so that the active material in the electrode is fixed and passes through the drying furnace 9. Then, the film is dried and wound on a winding roll 11 which is a winding mechanism via a roller 10 to produce a positive electrode sheet.

FIG. 7 shows a cross-sectional view of the electrode according to this example. On the electrode substrate 14, the first insulating layer 27 is disposed on the electrode layer 12 and on both sides adjacent portions which are edges of the electrode layer 12 (on both sides adjacent to the electrode layer in the direction orthogonal to the supply direction of the electrode substrate 14). The first insulating layer 27 is disposed so as to cover both sides in one direction of the electrode layer in a plane on the electrode substrate, and the electrode layer is formed on the electrode layer 12 (a plane of the electrode layer facing the electrode substrate). The second insulating layer 16 is arranged so as to have a width longer than 12. Thereby, the coverage to the electrode material edge part of an insulating material improves, and a short circuit defect can be reduced. That is, the electrode layer 12 of FIG. 7 is formed by the positive electrode material 5 discharged from the slit 24 of the die coater 18 shown in FIG. 6, and the first insulating material discharged from the

slits

25 and 26 of the die coater 18 shown in FIG. 19 forms the first insulating layer 27 of FIG. In other words, the die coater 18 is provided with slits for coating the insulating layer on both sides of the slits for coating the electrode layer. Then, the second insulating layer 16 shown in FIG. 7 is formed by the second insulating material 21 discharged from the slit of the die coater 20. Therefore, the length of the slit of the die coater 20 is longer than the length of the slit 24 of the die coater 18, and the width of the second insulating layer 16 in FIG. 7 is longer than that of the electrode layer 12.

In FIG. 7, the second insulating layer 16 does not protrude outside the first insulating layer 27, but may protrude outside the first insulating layer 27. Thereby, the second insulating layer 16 covers the electrode layer 12 so as to protrude to the outside of the first insulating layer 27, so that the coverage of the insulating layer is further improved.

In this example, regarding the production of the positive electrode sheet, the positive electrode material 5 is a mixture of an active material made of nickel, cobalt, and lithium manganate and carbon as a conductive additive, and a binder (binder) made of polyvinylidene fluoride. A slurry kneaded in a solution dissolved in N-methylpyrrolidone (NMP) was used. The first insulating material 19 was a slurry in which silica (SiO 2) powder was kneaded into a solution obtained by dissolving a binder (binder) made of polyvinylidene fluoride in N-methylpyrrolidone (NMP). The second insulating material 21 is a component that deposits a binder (binder) made of silica (SiO2) powder of styrene butadiene rubber, a surface layer of the positive electrode material, or a binder component of the first insulating material. A slurry kneaded in a solution dissolved in one ethanol-added water was used. That is, the solvent of the second insulating material is a solvent for precipitating the binder in the solvent of the electrode material and the solvent of the first insulating material. Moreover, the spray liquid 23 used the ethanol addition water which is one of the components which precipitate the binder component of positive electrode material.

The production of the negative electrode sheet is the same as the production process of FIG. 5. The negative electrode material is composed of a negative electrode active material made of a carbon material (carbon material) and a binder (binder) made of polyvinylidene fluoride with N-methylpyrrolidone ( A slurry kneaded in a solution dissolved in (NMP) was used. Moreover, about the 1st insulating material, the 2nd insulating material, and the spray liquid, the same thing as positive electrode sheet manufacture was used.

In the evaluation of the coverage ratio of the electrode material layer and the insulating material layer in this example, a laminate type battery was prepared, pressurized in a state before injecting the electrolytic solution, and a short circuit was determined based on whether or not the resistance value decreased. The results are summarized in Table 1.

In Table 1, the film thickness of the positive electrode layer indicates the film thickness after drying. Further, the comparative example is a result obtained without supplying the first insulating material 19 of FIG. From Table 1, it can be seen that although the film thickness after drying of the positive electrode layer is 50 μm or more, a short circuit occurs in the comparative example, but no short circuit occurs in this example.

As described above, in this embodiment, the electrode substrate supplied at a predetermined speed in the method of manufacturing a lithium ion secondary battery including the positive electrode, the negative electrode, and the separator that electrically separates the positive electrode and the negative electrode. The first insulating material is applied to both sides of the electrode material and the electrode material in the direction orthogonal to the supply direction of the electrode substrate, and the coated electrode material and the surface of the first insulating material are coated. The second insulating material is applied, the applied electrode material and the first and second insulating materials are dried and fixed, and the application of the second insulating material is performed between the electrode material and the first insulating material. An electrode sheet is manufactured downstream of the coating, and the electrode material constitutes the positive electrode and the negative electrode, and the first and second insulating materials constitute the separator.

Further, in a lithium ion secondary battery manufacturing apparatus, an electrode substrate delivery mechanism for delivering an electrode substrate at a predetermined speed, a first slit for applying an electrode material to the electrode substrate, and both sides of the first slit A first die coater having a second slit for coating the provided first insulating material; a third slit longer than the first slit; and the coated electrode material and the first A second die coater for applying a second insulating material to the surface of the insulating material; a drying furnace for heating and drying and fixing the electrode material and the first and second insulating materials applied to the electrode substrate; And a winding mechanism for winding up the electrode substrate to which the electrode material and the first and second insulating materials are fixed.

A lithium ion secondary battery including a positive electrode, a negative electrode, and a separator that electrically separates the positive electrode and the negative electrode, wherein the positive electrode and the negative electrode are electrode layers made of an electrode material on a sheet-like electrode substrate. The electrode layer is covered with an insulating layer made of an insulating material that constitutes the separator and constitutes a positive electrode sheet and a negative electrode sheet, respectively, and the positive electrode sheet and the negative electrode sheet are wound. The insulating layer includes a first insulating layer that covers both sides in one direction of the electrode layer in a plane on the electrode substrate, and a second insulating layer that covers a plane of the electrode layer that faces the electrode substrate, The first insulating layer is made of a first insulating material containing a first binder made of polyvinylidene fluoride, and the second insulating layer is made of a second insulating material containing a second binder made of styrene butadiene rubber. That the lithium-ion secondary battery.

This improves the coverage of the insulating material on the edge of the electrode layer and has the effect of reducing short-circuit defects.

In the present embodiment, an embodiment in which the die coater 18 that supplies the positive electrode material 5 and the first insulating material 19 and the die coater 20 that supplies the second insulating material 21 in the first embodiment are performed by one die coater will be described. .

FIG. 8 is a configuration diagram of the manufacturing process of the positive electrode sheet of the lithium ion secondary battery of this example. In FIG. 8, the positive electrode substrate 1 is fed at a predetermined speed from a positive substrate feed roll 2 that is an electrode substrate feed mechanism, and is supplied from a die coater 28 facing the roller 3. Two insulating materials 21 are applied.

FIG. 9 shows the die coater 28 of this embodiment. In FIG. 9, the positive electrode material 5 is discharged from the slit 29, and the first insulating material 19 is discharged from the

slits

30 and 31 provided on both sides of the slit 29. Then, the second insulating material 21 is discharged from the slit 32. That is, the die coater 28 is formed by applying the second insulating material 21 to the surfaces of the positive electrode material 5 and the first insulating material 19 discharged from the

slits

29, 30, 31. In other words, the slit 32 is provided in the front part of the positive electrode substrate in the feed direction. Others are the same as that of Example 1, and a positive electrode sheet is manufactured.

The electrode layer 12 of FIG. 7 is formed by the positive electrode material 5 discharged from the slit 29 of the die coater 28 shown in FIG. 9, and the first insulating material 19 discharged from the

slits

30 and 31 of the die coater 28 shown in FIG. Then, the first insulating layer 27 of FIG. 7 is formed. 7 is formed by the second insulating material 21 discharged from the slit 32 of the die coater 28 shown in FIG. Therefore, the length of the slit 32 of the die coater 28 is longer than the length of the slit 29, and the width of the second insulating layer 16 in FIG. 7 is longer than that of the electrode layer 12.

In FIG. 9, the length of the slit 32 of the die coater 28 is shorter than the length of the

slits

29, 30, 31 added, but may be longer. Thereby, since the second insulating layer 16 in FIG. 7 covers the electrode layer 12 so as to protrude outside the first insulating layer 27, the coverage of the insulating layer is further improved.

In the evaluation of the coverage ratio of the electrode material layer and the insulating material layer in this example, a laminate type battery was prepared, pressurized in a state before injecting the electrolytic solution, and a short circuit was determined based on whether or not the resistance value decreased. The results are summarized in Table 2.

In Table 2, the thickness of the positive electrode layer indicates the thickness after drying. Further, the comparative example is a result obtained without supplying the first insulating material of FIG. From Table 2, it can be seen that although the film thickness after drying of the positive electrode layer is 50 μm or more, a short circuit occurs in the comparative example, but no short circuit occurs in this example.

As described above, the embodiment described above describes an example in which a positive electrode material and first and second insulating materials are coated on one surface of a positive electrode substrate to manufacture a positive electrode sheet. When coating the positive electrode material and the first and second insulating materials on both surfaces of the positive electrode substrate, the positive electrode sheet wound around the take-up roll is reversed and the back surface is again applied through the same process. It can be realized by crafting. Moreover, also when manufacturing a negative electrode sheet, it is realizable by the same process.

Further, by using a slurry in which the second insulating material 21 is mixed with fine particles of polypropylene or polyethylene, it is possible to provide a shutdown property when the temperature rises due to a short circuit or the like. Moreover, the member which gives this shutdown property can also be added as a separator of another member. In addition, since this separate separator is a separator for providing shutdown properties, it can be made thinner than the separator made of the second insulating material.

In the above-described embodiments, the lithium ion secondary battery has been described as an example. However, the technical idea of the present invention is not limited to the lithium ion secondary battery, and the positive electrode, the negative electrode, and the positive electrode It can be widely applied to an electricity storage device (for example, a battery or a capacitor) provided with a separator that electrically separates the negative electrode.

As described above, in this embodiment, the electrode substrate supplied at a predetermined speed in the method of manufacturing a lithium ion secondary battery including the positive electrode, the negative electrode, and the separator that electrically separates the positive electrode and the negative electrode. The first insulating material is applied to both sides of the electrode material and the electrode material in the direction orthogonal to the supply direction of the electrode substrate, and the coated electrode material and the surface of the first insulating material The second insulating material is applied to the electrode material, and the applied electrode material and the first and second insulating materials are dried and fixed, and the electrode material constitutes the positive electrode and the negative electrode, and the first and second insulating materials are formed. An electrode sheet whose material constitutes a separator is manufactured.

Further, in addition to the separators made of the first and second insulating materials, a separator is provided as a separate member.

Also, in the lithium ion secondary battery manufacturing apparatus, the electrode substrate feeding mechanism for feeding the electrode substrate at a predetermined speed, the first slit for applying the electrode material to the electrode substrate, and both sides of the first slit are provided. The second electrode for coating the first insulating material, the first slit, and the second slit provided on the front side of the electrode substrate in the feeding direction of the electrode material and the first insulating material. A die coater having a third slit for coating the surface with the second insulating material, a drying furnace for heating and drying and fixing the electrode material and the first and second insulating materials coated on the electrode substrate; And a winding mechanism for winding up the electrode substrate to which the electrode material and the first and second insulating materials are fixed.

As described above, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment. *

1: Positive electrode substrate 2: Positive electrode substrate feed rolls 3, 6, 10:

Rollers

4, 7, 18, 20, 28: Die coater 5: Positive electrode material 8: Insulating material 9: Drying furnace 11: Winding roll 12: Electrode layer 13 : Electrode layer and die coater gap 14: electrode substrate 15: electrode substrate and die coater gap 16: second insulating layer 17: poor insulation portion 19: first insulating material 21: second insulating material 22: spraying Nozzle 23:

spray liquid

24, 25, 26, 29, 30, 31, 32: slit 27: first insulating layer

Claims

In a method for producing a lithium ion secondary battery comprising a positive electrode, a negative electrode, and a separator that electrically separates the positive electrode and the negative electrode,
A first insulating material is applied to the electrode substrate supplied at a predetermined speed to both sides of the electrode material and the electrode material in a direction perpendicular to the supply direction of the electrode substrate,
Applying a second insulating material to the surfaces of the coated electrode material and the first insulating material;
Drying and fixing the coated electrode material and the first and second insulating materials;
A method for producing a lithium ion secondary battery, wherein the electrode material constitutes the positive electrode and the negative electrode, and the first and second insulating materials constitute an electrode sheet constituting the separator.
It is a manufacturing method of the lithium ion secondary battery according to claim 1,
The method of manufacturing a lithium ion secondary battery, wherein the application of the second insulating material is performed downstream of the application of the electrode material and the first insulating material.
It is a manufacturing method of the lithium ion secondary battery according to claim 1,
A method of manufacturing a lithium ion secondary battery, wherein a separator is provided as a separate member in addition to the separators made of the first and second insulating materials.
It is a manufacturing method of the lithium ion secondary battery according to claim 2,
A method of manufacturing a lithium ion secondary battery, wherein a separator is provided as a separate member in addition to the separators made of the first and second insulating materials.
It is a manufacturing method of the lithium ion secondary battery according to claim 1,
The method of manufacturing a lithium ion secondary battery, wherein the solvent of the second insulating material is a solvent for precipitating a binder in the solvent of the electrode material and the solvent of the first insulating material.
An electrode substrate delivery mechanism for delivering the electrode substrate at a predetermined speed;
A first die coater having a first slit for applying an electrode material to the electrode substrate and a second slit for applying a first insulating material provided on both sides of the first slit. When,
A second die coater having a third slit longer than the first slit and applying a second insulating material to the surface of the coated electrode material and the first insulating material;
A drying furnace for heating and drying and fixing the electrode material and the first and second insulating materials applied to the electrode substrate;
An apparatus for manufacturing a lithium ion secondary battery, comprising: a winding mechanism that winds up the electrode substrate to which the electrode material and the first and second insulating materials are fixed.
It is a manufacturing apparatus of the lithium ion secondary battery according to claim 6,
Instead of the first die coater and the second die coater,
A first slit for applying an electrode material to the electrode substrate; a second slit for applying a first insulating material provided on both sides of the first slit; and the first slit And a third slit having a second slit applied to the surface of the coated electrode material and the first insulating material provided in the forward direction of the electrode substrate in the second slit. An apparatus for producing a lithium ion secondary battery comprising: a die coater.
It is a manufacturing apparatus of the lithium ion secondary battery according to claim 6,
The apparatus for producing a lithium ion secondary battery, wherein the solvent of the second insulating material is a solvent for precipitating a binder in the solvent of the electrode material and the solvent of the first insulating material.
A lithium ion secondary battery comprising a positive electrode, a negative electrode, and a separator that electrically separates the positive electrode and the negative electrode,
The positive electrode and the negative electrode are composed of an electrode layer made of an electrode material on a sheet-like electrode substrate, and the electrode layer is covered with an insulating layer made of an insulating material constituting the separator. The positive electrode sheet and the negative electrode sheet are wound and configured,
The insulating layer includes a first insulating layer that covers both side surfaces in one direction of the electrode layer in a plane on the electrode substrate, and a second insulating layer that covers a plane of the electrode layer that faces the electrode substrate. Consists of
The first insulating layer is made of a first insulating material including a first binder,
The lithium ion secondary battery, wherein the second insulating layer is made of a second insulating material including a second binder.
The lithium ion secondary battery according to claim 9,
The lithium ion secondary battery, wherein the first binder is a binder made of polyvinylidene fluoride, and the second binder is a binder made of styrene butadiene rubber.