JP2015146237A - Method of manufacturing battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a battery capable of being equipped with an excellent cut end surface and forming an electrode excellent in insulation properties.SOLUTION: Disclosed is a method of manufacturing a battery that has a cutting step for cutting off an electrode plate 51 (61) forming an active material layer 32 (42) on both surfaces of a metal foil 26 (36), respectively, by an abrasive water-jet device 45 that sprays high pressure fluid containing polishing agent particles and simultaneously forming a cut end surface on the metal foil 26 (36) and the active material layer 32 (42), respectively. An insulating coating 34 (44) is formed over the cut end surface of the metal foil 26 (36) and the active material layer 32 (42) by spraying of low pressure fluid containing insulating particles after cutting off the electrode plate 51 (61).

Description

  The present invention relates to a battery manufacturing method.

As a prior art regarding the manufacturing method of a battery, patent document 1 can be mentioned, for example.
Patent Document 1 discloses a battery manufacturing method including a corrosion cutting step of cutting a large electrode plate with a corrosive liquid sprayed at a high pressure and corroding an end face of a metal foil with the corrosive liquid.
In this corrosion cutting process, corrosive liquid is sprayed from the nozzle of the water jet device at a high pressure to cut the large electrode plate, but even if burrs or the like occur on the cut metal foil, the corrosive liquid adheres to the cut end face. Corrosion is caused by the remaining corrosive liquid, and burrs and the like are removed or reduced.

JP 2008-218378 A

However, since the technique disclosed in Patent Document 1 is the cutting of the electrode plate by a water jet device using a corrosive liquid, there is a problem that the corrosive liquid remaining on the electrode plate corrodes even the active material.
For this reason, when the electrode plate is cut by a water jet device using a corrosive liquid, it is necessary to clean the cut electrode plate.
Moreover, even if burrs or the like are removed or reduced by the corrosive liquid, burrs or the like may still remain, and if burrs or the like remain as foreign matter, the insulating properties of the electrode plate may be impaired. .

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a battery manufacturing method that can form an electrode having a good cut end face and having excellent insulating properties.

  In order to solve the above problems, the present invention cuts an electrode plate having active material layers formed on both sides of a metal foil by an abrasive water jet device that jets a high-pressure fluid containing abrasive particles, In the battery manufacturing method including a cutting step of simultaneously forming a cut end surface on each of the layer and the metal foil, the active material layer and the metal foil are formed by spraying a low-pressure fluid containing insulating particles after the electrode plate is cut. An insulating film is formed over the cut end surface.

In this invention, an electrode plate is cut | disconnected by injection of the high pressure fluid containing abrasive | polishing agent particle | grains in a cutting process, and a cutting | disconnection end surface is simultaneously formed in the active material layer and metal foil of an electrode plate.
When the electrode plate is cut, the cut end surface of the metal foil softer than the active material layer is formed slightly deeper than the cut end surface of the active material layer.
Since the low-pressure fluid containing the insulating particles is sprayed toward the active material layer and the cut end surface of the metal foil after the electrode plate is cut, the insulating particles adhere to and accumulate on the cut end surfaces of the active material layer and the metal foil. An insulating film is formed over the respective cut end surfaces of the material layer and the metal foil.
According to the present invention, the active material layer and the metal foil have a good cut end face that hardly generates burrs and the like, and an insulating film made of insulating particles contained in the low-pressure fluid is formed on the cut end face. The insulation of the electrode obtained from a board can be improved.
In addition, in the insulating coating formed over the active material layer and the cut end surface of the metal foil, the portion corresponding to the metal foil is thicker than the portion corresponding to the active material layer, thereby further improving the insulation of the electrode body. be able to.

In the battery manufacturing method, the electrode plate may be cut by inclining an injection axis of the high-pressure fluid with respect to a plate surface of the electrode plate.
In this case, the cut end faces of the active material layer and the metal foil have a larger area than the cut end face when the high pressure fluid ejection axis is cut without inclining, so that an insulating coating can be easily formed. it can.
In particular, in a state where the cut end surface of the active material layer and the metal foil faces upward, when the low pressure fluid is sprayed from above toward the cut end surface of the active material layer and the metal foil, the insulating particles contained in the low pressure fluid are applied to the cut end surface. It becomes easy to adhere and an insulating film can be formed more reliably.

In the method for manufacturing an electrode body for a battery, the insulating particles may be alumina.
In this case, it is possible to form an insulating film having a high insulating property with alumina over the cut end faces of the active material layer and the metal foil.

In the battery manufacturing method, the abrasive particles may be made of the same material as the insulating particles.
In this case, since the abrasive particles remain on the cut end surface formed at the time of cutting the electrode plate, when the insulating particles are made of the same material as the insulating particles, the insulating particles adhere to the remaining abrasive particles. easy.
For this reason, it becomes easy to form the insulating film by an insulating particle by the cut end surface of an active material layer and metal foil.

In the battery manufacturing method, the high-pressure fluid and the low-pressure fluid may be N-methyl-2-pyrrolidone (NMP).
In this case, since N-methyl-2-pyrrolidone is used, the active material layer does not change even if the droplets of N-methyl-2-pyrrolidone remain after the electrode plate is cut and the insulating film is formed. Further, the electrode performance is not deteriorated due to the alteration of the active material layer.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the battery which can form an electrode excellent in insulation while providing a favorable cut end surface can be provided.

It is a perspective view which shows the structure of the secondary battery which concerns on 1st Embodiment. It is a disassembled perspective view which decomposes | disassembles and shows a part of electrode body with which a secondary battery is provided. It is a cross-sectional view of the principal part of the electrode body with which the secondary battery is provided. It is explanatory drawing explaining the manufacturing process of a positive electrode (negative electrode). (A) is explanatory drawing explaining the cutting | disconnection of the positive electrode (negative electrode) electrode plate of an electrode body, (b) is explanatory drawing explaining formation of the insulating film to the cutting | disconnection end surface of a positive electrode (negative electrode) electrode plate. . (A) is explanatory drawing explaining the cutting | disconnection of the positive electrode (negative electrode) electrode plate of the electrode body which concerns on 2nd Embodiment, (b) is forming an insulating film in the cut end surface of a positive electrode (negative electrode) electrode plate. It is explanatory drawing explaining these.

(First embodiment)
The battery manufacturing method according to the first embodiment will be described below with reference to the drawings.
First, a stacked battery that is an object of the battery manufacturing method of the present invention will be described.
The stacked battery according to the present embodiment is a secondary battery mounted on a vehicle, for example, a lithium secondary battery or a nickel hydride secondary battery.

A secondary battery 10 shown in FIG. 1 includes a case 11 having a substantially rectangular parallelepiped shape as a whole.
The longitudinal direction of the case 11 shown in FIG. 1 is shown as the left-right direction, the height direction of the case 11 is shown as the vertical direction, and the short direction of the case 11 is shown as the front-rear direction.
The case 11 has a box-shaped case main body 12 and a lid 13 that seals an opening (not shown) of the case main body 12.

The lid 13 is fixed to the case body 12 by laser welding.
Both the case main body 12 and the lid 13 are made of a metal material (for example, aluminum).
A cylindrical positive electrode terminal 14 and a negative electrode terminal 15 protrude from the outer surface of the lid 13.
The positive terminal 14 and the negative terminal 15 are insulated from the case 11.
The lid 13 is provided with an electrolyte injection port 16 and a safety valve 17 for injecting an electrolyte.

As shown in FIG. 1, the case body 12 accommodates a flat, substantially rectangular parallelepiped electrode body 20.
As shown in FIG. 2, the electrode body 20 includes a sheet-like positive electrode 21 and a negative electrode 22, and a sheet-like separator 23 interposed between the positive electrode 21 and the negative electrode 22.
The separator 23 is formed of an insulating material that enables the electrolyte solution to flow.
In the electrode body 20, the positive electrodes 21 and the negative electrodes 22 are alternately stacked via separators 23.
In FIG. 2, for convenience of explanation, only one positive electrode 21 and negative electrode 22 and three separators 23 are illustrated, but the electrode body 20 includes a large number of positive electrodes 21, negative electrodes 22, and separators 23.

As shown in FIG. 1, the electrode body 20 includes a positive current collector 24 connected to the positive terminal 14 and a negative current collector 25 connected to the negative terminal 15.
The electrode body 20 is accommodated in the case 11 while being covered with an insulating bag (not shown) formed of an insulating material.
The case 11 is filled with an electrolytic solution. The electrolytic solution is filled through the electrolytic solution injection port 16 after the electrode body 20 is accommodated in the case 11.
The electrolytic solution is an electrolytic solution according to the type of secondary battery such as a lithium secondary battery or a nickel hydride secondary battery.

Next, the positive electrode 21 will be described.
As shown in FIGS. 2 and 3, the positive electrode 21 includes a positive electrode metal foil 26 as a positive electrode current collector having a rectangular sheet shape.
The positive electrode metal foil 26 is formed of a metal material corresponding to the type of secondary battery such as a lithium secondary battery or a nickel hydride secondary battery.
The positive electrode metal foil 26 of the present embodiment is made of aluminum.
As shown in FIG. 2, the positive electrode metal foil 26 includes an edge portion 27 that faces the lid body 13, an edge portion 28 that faces the bottom portion of the case body 12, an edge portion 29 on the right side of the edge portions 27 and 28, It has an edge 30 on the left side of the edges 27 and 28.
In the present embodiment, the left-right direction in the secondary battery 10 and the width direction of the positive electrode metal foil 26 coincide.
As shown in FIG. 2, the positive electrode metal foil 26 includes a rectangular positive electrode tab portion 31 protruding from the edge portion 27 and extending.
The positive electrode tab portion 31 is formed near the left edge 30 on the edge 27 of the positive metal foil 26.
The positive electrode tab portions 31 of all the positive electrodes 21 are aggregated to form the positive electrode current collector 24.

A positive electrode active material is applied to one surface (front surface in FIG. 2) and the other surface (rear surface in FIG. 2) of the positive electrode metal foil 26 to form a positive electrode active material layer 32.
The positive electrode active material layer 32 is formed to be a rectangular region in the region of the positive electrode metal foil 26 excluding the positive electrode tab portion 31.
As shown in FIG. 2, in the positive electrode metal foil 26, the regions along the edges 27, 28 while maintaining a certain distance from the edges 27, 28 are uncoated areas where the positive electrode active material is not applied. .
Therefore, the vertical height of the positive electrode active material layer 32 is set smaller than the vertical height of the positive electrode metal foil 26.
The width of the positive electrode active material layer 32 is substantially the same as the width of the positive electrode metal foil 26.

As shown in FIG. 3, in the present embodiment, an inclined surface that is inclined with respect to the thickness direction of the positive electrode 21 is formed at the left end of the positive electrode 21 in the width direction.
The inclined surface is formed by the surface of the edge portion 30 of the positive electrode metal foil 26 and the surface of the edge portion 33 (33A, 33B) of the positive electrode active material layer 32 formed on both surfaces of the positive electrode metal foil 26.
The edge portion 30 and the edge portions 33A and 33B are set to the same inclination angle, the edge portions 33A and 33B are in the same plane, and the edge portion 30 is positioned slightly deeper inward than the edge portions 33A and 33B.
An insulating coating 34 is formed over the edge 30 of the positive metal foil 26 and the edges 33A and 33B of the positive electrode active material layer 32.
The insulating coating 34 is a coating formed in order to improve the insulation in the electrode body 20, and is a coating in which alumina as insulating particles is deposited.
Although not shown, an inclined surface inclined with respect to the thickness direction of the positive electrode 21 is formed at the right end of the positive electrode 21 in the width direction, and the left and right inclined surfaces of the positive electrode 21 are parallel to each other. is there.

Next, the negative electrode 22 will be described.
As shown in FIG. 2, the negative electrode 22 includes a negative electrode metal foil 36 as a negative electrode current collector having a rectangular sheet shape.
The negative electrode metal foil 36 is formed of a metal material corresponding to the type of secondary battery such as a lithium secondary battery or a nickel hydride secondary battery.
The negative electrode metal foil 36 of the present embodiment is made of copper.
As shown in FIG. 2, the negative electrode metal foil 36 includes an edge portion 37 that faces the lid body 13, an edge portion 38 that faces the bottom portion of the case body 12, an edge portion 39 on the right side of the edge portions 37 and 38, And an edge 40 on the left side of the edges 37 and 38.
In the present embodiment, the left-right direction in the secondary battery 10 and the width direction of the negative electrode metal foil 36 coincide.
As shown in FIG. 2, the negative electrode metal foil 36 includes a rectangular negative electrode tab portion 41 that protrudes from the edge portion 37 and extends.
The negative electrode tab portion 41 is formed near the right edge portion 39 in the edge portion 37 of the negative electrode metal foil 36.
The negative electrode tab portions 41 of all the negative electrodes 22 are integrated to form the negative electrode current collector 25.

A negative electrode active material is applied to one surface (front surface in FIG. 2) and the other surface (rear surface in FIG. 2) of the negative electrode metal foil 36 to form a negative electrode active material layer 42.
As shown in FIG. 2, in the negative electrode metal foil 36, a region along the edges 37 and 38 while maintaining a certain distance from the edges 37 and 38 is an uncoated area where the positive electrode active material is not applied. .
Therefore, the vertical height of the negative electrode active material layer 42 is set smaller than the vertical height of the negative electrode metal foil 36.
The width of the negative electrode active material layer 42 is substantially the same as the width of the negative electrode metal foil 36.

As shown in FIG. 3, in the present embodiment, an inclined surface that is inclined with respect to the thickness direction of the negative electrode 22 is formed at the left end of the negative electrode 22 in the width direction.
The inclined surface is formed by the surface of the edge portion 40 of the negative electrode metal foil 36 and the surface of the edge portion 43 (43A, 43B) of the negative electrode active material layer 42 formed on both surfaces of the negative electrode metal foil 36.
The edge portion 40 and the edge portions 43A and 43B are set at the same inclination angle, the edge portions 43A and 43B are in the same plane, and the edge portion 40 is located slightly deeper inward than the edge portions 43A and 43B.
An insulating coating 44 is formed across the edge 40 of the negative electrode metal foil 36 and the edges 43A and 43B of the negative electrode active material layer 42.
The insulating coating 44 is a coating formed in order to improve the insulation in the electrode body 20, and is a coating on which alumina as insulating particles is deposited.
Although not illustrated, an inclined surface inclined with respect to the thickness direction of the negative electrode 22 is formed at the right end of the negative electrode 22 in the width direction, and the left and right inclined surfaces of the negative electrode 22 are parallel to each other. is there.

Next, manufacture of the positive electrode 21 and the negative electrode 22 of the electrode body 20 of the secondary battery 10 of this embodiment will be described with reference to FIGS. 4, 5 (a), and 5 (b).
As shown in FIG. 4, the positive electrode 21 is manufactured by applying a positive electrode active material on both surfaces of the positive electrode metal foil sheet 50 to form a positive electrode active material layer 32 and forming a positive electrode plate 51 as an electrode plate. And a cutting step of cutting the edge of the positive electrode plate 51 and forming the insulating coating 34 on the cut end face.
In addition, the manufacturing process of the negative electrode 22 includes the coating process with respect to the negative electrode metal foil sheet 60, and the cutting process of the negative electrode plate 61 as an electrode plate similarly to the manufacturing process of the positive electrode 21.
The longitudinal direction orthogonal to the short direction of the positive electrode metal foil sheet 50 (negative electrode metal foil sheet 60) shown in FIG.
In FIG. 4, the thickness of the positive electrode active material layer 32 (negative electrode active material layer 42) is exaggerated for convenience of explanation.

First, in a coating process, as shown in FIG. 4, the positive electrode active material of a slurry is applied on both surfaces of the positive electrode metal foil sheet 50 continuous in the longitudinal direction.
At this time, the positive electrode active material is applied with a predetermined length with respect to the short direction of the positive electrode metal foil sheet 50, and the positive electrode active material is applied over the width of the positive electrode metal foil sheet 50.
The positive electrode active material is dried to form the positive electrode active material layer 32, whereby the positive electrode plate 51 is obtained. Next, the process proceeds to a cutting step.

As shown in FIG. 4, in the cutting step, the positive electrode plate 51 is cut along the planned cutting lines A1 and A2.
The planned cutting line A1 includes a portion that simultaneously cuts the positive electrode metal foil 26 and the positive electrode active material layer 32, but only the positive metal foil 26 is cut along the planned cutting line A2.
In the present embodiment, the positive electrode plate 51 is cut using an abrasive water jet device 45 that injects a high-pressure fluid (350 MPa) containing abrasive particles.
The abrasive water jet device 45 is a known device.
As shown in FIG. 5A, the abrasive water jet device 45 is provided with a nozzle 46 for injecting abrasive particles contained in the high-pressure fluid.
In the present embodiment, N-methyl-2-pyrrolidone (NMP), which is an organic solvent for making the positive electrode active material into a slurry, is used as the fluid used as the high pressure fluid.
The abrasive particles contained in the high-pressure fluid are alumina fine particles.

In the present embodiment, as shown in FIG. 4, the planned cutting line A <b> 1 in a state where the positive electrode plate 51 is horizontal (the thickness direction of the positive electrode active material layer 32 and the positive electrode metal foil 26 matches the vertical direction). The positive electrode plate 51 is cut along the line.
As shown in FIG. 5A, the positive electrode plate 51 is cut by inclining the injection axis P of the high-pressure fluid with respect to the vertical direction (the thickness direction of the positive electrode active material layer 32 and the positive electrode metal foil 26). The posture of the nozzle 46 is set.
In the present embodiment, the inclination angle θ of the injection axis P with respect to the thickness direction of the positive electrode active material layer 32 and the positive electrode metal foil 26 is set to 30 degrees.

When the abrasive water jet device 45 cuts the positive electrode plate 51 along the planned cutting line A1, the positive metal foil 26 and the positive electrode active material layer 32 are cut simultaneously.
As shown in FIG. 5A, an edge 30 as a cut end face is formed on the positive electrode metal foil 26, and an edge 33 (33A, 33B) as a cut end face is formed on the positive electrode active material layer 32. .
At the time of cutting, the abrasive particles come into contact with the edge 30 of the positive electrode metal foil 26 and the edges 33A and 33B of the positive electrode active material layer 32. However, since the positive electrode metal foil 26 is softer than the positive electrode active material layer 32, It is formed at a position slightly deeper inward than the edges 33A and 33B.
In addition, in edge part 30,33A, 33B as a cutting end surface, neither generation | occurrence | production of heat | fever denaturation nor melting dross exists, and a favorable cutting end surface is formed.

In this embodiment, since the injection axis P of the high-pressure fluid is inclined with respect to the thickness direction of the positive electrode active material layer 32 and the positive electrode metal foil 26, the abrasive particles contained in the high-pressure fluid are formed on the positive electrode plate 51 at the time of cutting. Are likely to remain on the edges 30, 33A, 33B.
Further, when the insulating coating 34 is formed on the cut edges 30, 33A, 33B due to the inclination of the injection axis P of the high-pressure fluid, the insulating particles are easily attached and deposited on the edges 30, 33A, 33B. .
The inclination angle θ of the injection axis P with respect to the vertical direction is preferably in the range of 20 to 40 degrees in terms of the ease of forming the insulating coating 34, and the inclination angle of 25 to 35 degrees is preferably the positive electrode active material layer 32 and The abrasive particles contained in the high-pressure fluid enter the interface of the positive electrode metal foil 26, which is the optimum range in terms of preventing peeling.

Next, as shown in FIG. 5B, the insulating coating 34 is formed on the edges 30, 33 </ b> A, 33 </ b> B using an abrasive water jet device 47 that injects a low-pressure fluid (20 MPa) containing insulating particles. .
The abrasive water jet device 47 is a known device.
As shown in FIG. 5, the abrasive water jet device 47 includes a nozzle 48 that ejects a low-pressure fluid containing insulating particles.
The nozzle 48 has a nozzle hole diameter L so that fluid is ejected from the nozzle 48 at a low pressure.
In the present embodiment, N-methyl-2-pyrrolidone (NMP), which is an organic solvent for making the positive electrode active material into a slurry, is used as the fluid used as the low pressure fluid.
The insulating particles to be included in the low-pressure fluid are the same alumina fine particles as the abrasive particles.

In the present embodiment, as shown in FIG. 5B, in a state where the cut positive electrode plate 51 is leveled, the low-pressure fluid containing insulating particles is applied from above to the edges 30, 33A of the positive electrode plate 51. , Spray toward 33B.
The direction of the nozzle 48 may be any direction as long as the low-pressure fluid containing insulating particles is reliably sprayed to the edges 30, 33A, 33B of the positive electrode plate 51.
By spraying the low-pressure fluid containing insulating particles on the edges 30, 33A, 33B of the positive electrode plate 51, the insulating particles are attached and deposited on the edges 30, 33A, 33B, and the edges 30, 33A, 33B. An insulating film 34 is formed over the entire area.

Since the edge portion 30 is formed at a position slightly deeper inward than the edge portions 33A and 33B, the portion corresponding to the edge portion 30 in the insulating coating 34 is thicker than the portion corresponding to the edge portions 33A and 33B. Become.
In the present embodiment, since the positive electrode plate 51 is cut using alumina as abrasive particles, the alumina remains on the edges 30, 33 </ b> A, and 33 </ b> B before the insulating coating 34 is formed.
For this reason, when the low-pressure fluid containing the insulating particles of alumina is sprayed, the alumina of the insulating particles adheres to the alumina of the abrasive particles remaining on the edges 30, 33A, 33B.
By adhering the insulating particles of alumina to the abrasive particles of alumina, the insulating particles of alumina are easily deposited on the edges 30, 33A, 33B.

After forming the edge 30 of the positive electrode metal foil 26, the edges 33A and 33B of the positive electrode active material layer 32, and the insulating coating 34, although not shown, the positive electrode metal foil 26 as a cut end face is obtained by cutting the positive electrode plate 51. The edge portion 29 and the edge portions 33A and 33B of the positive electrode active material layer 32 are formed.
Next, an insulating film 34 is formed on the edges 29, 33A, 33B.
After the insulating coating 34 is formed, the positive electrode plate 51 is cut along the planned cutting line A2.
When the positive electrode plate 51 is cut along the planned cutting line A2, the positive electrode tab portion 31 is formed, and the positive electrode 21 is obtained.

Next, manufacture of the negative electrode 22 of the electrode body 20 of the secondary battery of this embodiment will be described with reference to FIGS. 4, 5 (a), and 5 (b).
First, in a coating process, as shown in FIG. 4, a negative electrode active material is coated on both surfaces of the negative electrode metal foil sheet 60 continuous in a longitudinal direction.
At this time, the negative electrode active material is applied with a predetermined length with respect to the short direction of the negative electrode metal foil sheet 60, and the negative electrode active material is applied over the width of the negative electrode metal foil sheet 60.
The negative electrode active material is dried to form the negative electrode active material layer 42, whereby the negative electrode plate 61 is obtained. Next, the cutting process proceeds.

As shown in FIG. 4, in the cutting step, the periphery of the negative electrode plate 61 is cut along the planned cutting lines B1 and B2.
The planned cutting line B1 includes a portion that simultaneously cuts the negative electrode metal foil 36 and the negative electrode active material layer 42, but only the negative electrode metal foil 36 is cut along the planned cutting line B2.
In this embodiment, the negative electrode plate 61 is cut using an abrasive water jet device 45 that injects a high-pressure fluid (350 MPa) containing alumina as abrasive particles, similarly to the cutting of the positive electrode plate 51.

In the present embodiment, as shown in FIG. 4, the planned cutting line B1 in a state in which the negative electrode plate 61 is horizontal (the thickness direction of the negative electrode active material layer 42 and the negative electrode metal foil 36 coincides with the vertical direction). The negative electrode plate 61 is cut along the line.
As shown in FIG. 5A, the negative electrode plate 61 is cut by inclining the injection axis P of the high-pressure fluid with respect to the vertical direction (the thickness direction of the negative electrode active material layer 42 and the negative electrode metal foil 36). The posture of the nozzle 46 is set.
In the present embodiment, the inclination angle θ of the injection axis P with respect to the thickness direction of the negative electrode active material layer 42 and the negative electrode metal foil 36 is set to 30 degrees.

When the abrasive water jet device 45 cuts the negative electrode plate 61 along the planned cutting line B1, the negative electrode metal foil 36 and the negative electrode active material layer 42 are cut simultaneously.
As shown in FIG. 5A, an edge 39 as a cut end face is formed on the negative electrode metal foil 36, and an edge 43 (43A, 43B) as a cut end face is formed on the negative electrode active material layer 42. .
At the time of cutting, the abrasive particles come into contact with the edge 39 of the negative electrode metal foil 36 and the edges 43A and 43B of the negative electrode active material layer 42. However, since the negative electrode metal foil 36 is softer than the negative electrode active material layer 42, the edge 39 is It is formed at a position slightly deeper inward than the edges 43A and 43B.
In addition, in edge part 39, 43A, 43B as a cutting end surface, neither generation | occurrence | production of a heat | fever denaturation nor melt | dissolution dross exists, and a favorable cutting end surface is formed.

In the present embodiment, since the injection axis P of the high pressure fluid is inclined with respect to the thickness direction of the negative electrode active material layer 42 and the negative electrode metal foil 36, the abrasive particles included in the high pressure fluid are cut into the negative electrode plate 61. It tends to remain on the edges 39, 43A, 43B that are sometimes formed.
Further, when the insulating coating 44 is formed on the cut edges 39, 43A, 43B due to the inclination of the injection axis P of the high-pressure fluid, the insulating particles are easily attached and deposited on the edges 39, 43A, 43B. .

  Next, as shown in FIG. 5B, an insulating coating 44 is formed on the edges 39, 43A, and 43B using an abrasive water jet device 47 that injects a low-pressure fluid (20 MPa) containing insulating particles. .

In the present embodiment, as shown in FIG. 5B, the low-pressure fluid containing insulating particles is applied from above to the edges 39, 43 </ b> A of the negative electrode plate 61 with the cut negative electrode plate 61 horizontal. , Spray toward 43B.
The direction of the nozzle 48 only needs to be a direction in which the low-pressure fluid containing insulating particles is reliably sprayed to the edges 39, 43A, 43B of the negative electrode plate 61.
By spraying low-pressure fluid containing insulating particles on the edges 39, 43A, 43B of the negative electrode plate 61, the insulating particles adhere to and deposit on the edges 39, 43A, 43B, and the edges 39, 43A, 43B. An insulating film 44 is formed over the entire area.

Since the edge 39 is formed at a position slightly deeper inward than the edges 43A and 43B, the portion corresponding to the edge 39 in the insulating coating 44 is thicker than the portion corresponding to the edges 43A and 43B. .
In this embodiment, since the negative electrode plate 61 is cut using alumina as abrasive particles, the alumina remains on the edges 39, 43A, and 43B before the formation of the insulating coating.
For this reason, when the low-pressure fluid containing the insulating particles of alumina is sprayed, the alumina of the insulating particles adheres to the alumina of the abrasive particles remaining on the edges 39, 43A, and 43B.
By adhering the insulating particles of alumina to the abrasive particles of alumina, the insulating particles of alumina easily deposit on the edges 39, 43A, and 43B.

After forming the edge 39 of the negative electrode metal foil 36, the edges 43A and 43B of the negative electrode active material layer 42, and the insulating coating 44, although not shown, the negative electrode metal foil 36 as a cut end face is obtained by cutting the negative electrode plate 61. Edge 40 and the edges 43A and 43B of the negative electrode active material layer 42 are formed.
Next, an insulating coating 44 is formed on the edges 40, 43A, 43B.
After the insulating coating 44 is formed, the negative electrode plate 61 is cut along the planned cutting line B2.
When the negative electrode plate 61 is cut along the planned cutting line B2, the negative electrode tab portion 41 is formed, and the negative electrode 22 is obtained.

Once the positive electrode 21 and the negative electrode 22 are obtained, the positive electrode 21 and the negative electrode 22 are then stacked via the separator 23 to form the electrode body 20.
The electrode body 20 is accommodated in an insulating bag (not shown) formed of an insulating material.
The plurality of positive electrode tab portions 31 are combined and connected to the positive electrode terminal 14, and similarly, the plurality of negative electrode tab portions 41 are combined and connected to the negative electrode terminal 15.
The electrode body 20 housed in an insulating bag (not shown) is housed in the case body 12, and after the electrode body 20 is housed in the case body, the lid body 13 is welded to the case body 12.
Thereafter, the electrolyte solution is filled into the case 11 from an electrolyte solution inlet (not shown) provided in the case 11.

The battery manufacturing method according to this embodiment has the following effects.
(1) The positive electrode (negative electrode) metal foil 26 (36) and the positive electrode (negative electrode) active material layer 32 (42) have a good cut end face that hardly generates burrs and the like, and has an insulating property contained in the low-pressure fluid. An insulating coating 34 (44) made of particles is formed on the cut end face. Therefore, the insulation of the electrode body 20 obtained from the positive electrode (negative electrode) electrode plate 51 (61) can be improved. In addition, in the insulating coating 34 (44) formed over the cut end face, the portion corresponding to the positive electrode (negative electrode) metal foil 26 (36) is from the portion corresponding to the positive electrode (negative electrode) active material layer 32 (42). The insulation of the electrode body 20 can be further improved.

(2) The positive electrode (negative electrode) electrode plate 51 (61) is cut by inclining the injection axis P of the high-pressure fluid with respect to the plate surface of the positive electrode (negative electrode) electrode plate 51 (61). For this reason, the cutting end surface has a larger area than the cutting end surface in the case of cutting without inclining the injection axis P of the high-pressure fluid, and the abrasive particles are likely to remain on the cutting end surface. Since the abrasive particles are likely to remain on the cut end surface, the insulating particles can easily adhere to the abrasive particles, and an insulating coating can be easily formed. In particular, in a state where the cut end face is upward, when the low-pressure fluid is ejected from the upper side toward the lower cut end face, the insulating particles contained in the low-pressure fluid are more likely to adhere to the cut end face, and the insulating coating is more reliably attached. Can be formed.

(3) Since the insulating particles are alumina, it is possible to form the insulating coating 34 (44) having high insulating properties over the cut end surface.

(4) Since the abrasive particles are the same material as the insulating particles, the abrasive particles remain on the cut end face. When the insulating particles are made of the same material as the abrasive particles, the insulating particles are likely to adhere to the remaining abrasive particles. For this reason, the insulating coating 34 (44) is easily formed by the cut end face.

(Second Embodiment)
Next, a battery manufacturing method according to the second embodiment will be described.
This embodiment is an example of cutting from both surfaces of a positive electrode plate and a negative electrode plate.
About the same structure as 1st Embodiment, description of 1st Embodiment is used and a code | symbol is used in common.

In the present embodiment, in the cutting step, cutting is performed from the plate surfaces on both sides of the positive electrode plate 51, and the insulating coating 54 is formed from the plate surfaces on both sides of the positive electrode plate 51 after cutting.
In the present embodiment, similarly to the first embodiment, in the cutting step, the periphery of the positive electrode plate 51 is cut along the planned cutting lines A1 and A2.
First, as shown in FIG. 5A, the positive electrode plate 51 is cut by inclining the injection axis P of the high-pressure fluid in a state where the positive electrode plate 51 is horizontal.
After the cutting, a cut end face is formed on the positive electrode metal foil 26 and an edge 33 (33A, 33B) as a cut end face is formed on the positive electrode active material layer 32.
Next, the plate surface of the cut positive electrode plate 51 is turned upside down, and, as shown in FIG. The electrode plate 51 is cut.
By the second cutting, an edge 30 as a final cut end face is formed on the positive electrode metal foil 26, and an edge 33C as a final cut end face is formed on the edge 33B side of the positive electrode active material layer 32. Is done.

In this embodiment, the edge 30 of the positive electrode metal foil 26 is formed at a position slightly deeper inward than the edges 33A and 33C by cutting twice from the plate surfaces on both sides.
The edge portion 30 has a mountain-shaped cross section in which the center in the thickness direction of the positive electrode metal foil 26 faces outward.
The surface of the edge portion 33A and the surface of the edge portion 33C are line symmetric with respect to the center in the thickness direction of the positive electrode metal foil 26.

Next, as shown in FIG. 6 (b), edges 30 and 33 A are formed from the plate surfaces on both sides of the cut positive electrode plate 51 using an abrasive water jet device 47 that ejects a low-pressure fluid containing insulating particles. , 33C is formed with an insulating film 54.
In the present embodiment, low-pressure fluid containing insulating particles is ejected from one plate surface of the positive electrode plate 51, and further, the positive electrode plate 51 is inverted and insulated by ejecting low-pressure fluid containing insulating particles. The conductive film 54 is formed.
In the present embodiment, as in the first embodiment, N-methyl-2-pyrrolidone (NMP), which is an organic solvent for producing a positive electrode active material slurry, is used as the fluid used as the low-pressure fluid.
Insulating particles contained in the low-pressure fluid are alumina fine particles.

After forming the edge 30 of the positive electrode metal foil 26, the edges 33A and 33C of the positive electrode active material layer 32, and the insulating coating 54, although not shown, the positive electrode metal foil 26 as a cut end face is cut by cutting the positive electrode plate 51. The edge 29 and the edges 33A and 33C of the positive electrode active material layer 32 are formed.
Next, an insulating film 54 is formed on the edges 29, 33A, 33C.
After the insulating coating 34 is formed, the positive electrode plate 51 is cut along the planned cutting line A2.
When the positive electrode plate 51 is cut along the planned cutting line A2, the positive electrode tab portion 31 is formed, and the positive electrode 21 is obtained.

In the present embodiment, similarly to the positive electrode plate 51, the negative electrode plate 61 is cut to form the edge 39 of the negative electrode metal foil 36 and the edges 43 A and 43 C of the negative electrode active material layer 42. , 43A, 43C, an insulating film 64 is formed.
After forming the edge 39 of the negative electrode metal foil 36, the edges 43A and 43C of the negative electrode active material layer 42, and the insulating coating 64, the negative electrode metal foil 36 as a cut end face is cut by cutting the negative electrode plate 61, although not shown. Edge portions 43A and 43C of the edge portion 40 and the negative electrode active material layer 42 are formed.
Next, an insulating film 64 is formed on the edges 40 and 43.
After the insulating coating 64 is formed, the negative electrode plate 61 is cut along the planned cutting line B2.
When the negative electrode plate 61 is cut along the planned cutting line B2, the negative electrode tab portion 41 is formed, and the negative electrode 22 is obtained.

According to this embodiment, there exists an effect equivalent to the effect of 1st Embodiment.
In addition, since the surface of the edge portion 33A and the surface of the edge portion 33C are axisymmetric with respect to the center in the thickness direction of the positive electrode metal foil 26, the insulating coating 54 (64) is the insulating property of the first embodiment. Compared to the coating 34 (44), it is difficult to peel off.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.

In the above embodiment, alumina fine particles are used as the abrasive particles for cutting the electrode plate. However, the abrasive particles are not limited to alumina, and ceramics such as garnet, cubic boron nitride, silicon carbide, silicon nitride, zirconia, etc. Fine particles of a system material may be used.
In the above embodiment, the insulating particles forming the insulating film are alumina, but the present invention is not limited to this. For example, cubic boron nitride, silicon carbide, silicon nitride, or zirconia may be used as the insulating particles.
In the above embodiment, the abrasive particles are made of the same material as the insulating particles. However, the present invention is not limited to this, and the abrasive particles may be made of a material different from the insulating particles. For example, the abrasive particles may be garnet and the insulating particles may be alumina.
In the above embodiment, the electrode plate is cut by inclining the injection axis of the high-pressure fluid with respect to the plate surface of the electrode plate, but it is essential to incline the injection axis of the high-pressure fluid with respect to the plate surface of the electrode plate. is not. For example, the electrode plate may be cut with the injection axis of the high-pressure fluid perpendicular to the plate surface of the electrode plate. Moreover, although the plate surface of the electrode plate is made horizontal when the electrode plate is cut and the film is formed, the plate surface of the electrode plate is not necessarily horizontal.
In the above embodiment, the pressure of the high-pressure fluid is 350 MPa, but this is not a limitation. For example, the pressure of the high-pressure fluid may be set in the range of 200 to 400 MPa, and in this pressure range, it is possible to form a good cut end face with almost no burrs or the like.
In the above embodiment, the nozzle hole diameter for injecting the low-pressure fluid is set, but the specific nozzle hole diameter may be set, for example, in the range of 0.1 mm to 3.0 mm. In the range of the nozzle hole diameter, a good insulating film can be reliably formed by jetting a low-pressure fluid containing insulating particles.
In the above embodiment, although not specifically described, a protective layer made of alumina, which is an insulating material, may be formed on the surface of the active material layer on both surfaces of the electrode plate, for example. When the protective layer is formed, when forming the insulating film on the cut end face, if the insulating particles forming the insulating film are alumina, the protective layer alumina and the insulating particle alumina are likely to adhere to each other, An insulating coating that is difficult to peel off can be formed.
In the above embodiment, the insulating coating is formed over the active material layer and the cut end surface of the metal foil by jetting the low-pressure fluid containing insulating particles using an abrasive water jet device, but this is not restrictive. For example, an insulating coating may be formed over the active material layer and the cut end surface of the metal foil by low-temperature spraying insulating particles using a low-pressure fluid as a gas.
In the above embodiment, the laminated electrode body is exemplified, but the electrode body may be, for example, a wound electrode body, and the electrode body is a metal that can be cut simultaneously by at least an abrasive water jet device. Any structure having a foil and an active material layer may be used.
In the above embodiment, the high-pressure fluid and the low-pressure fluid are liquid N-methyl-2-pyrrolidone (NMP). However, the high-pressure fluid and the low-pressure fluid may be water, for example. In the case of using water, if the water is removed by evaporation after the electrode plate is cut and the insulating film is formed, the electrode performance is not deteriorated. Further, either one of the high pressure fluid and the low pressure fluid may be water.

DESCRIPTION OF SYMBOLS 10 Secondary battery 20 Electrode body 21 Positive electrode 22 Negative electrode 23 Separator 26 Positive electrode metal foil 29, 30 Edge (as cut end face)
32 Positive electrode active material layer 33 (33A, 33B, 33C) Edge (as cut end face)
34, 44 Insulating coating 36 Negative electrode metal foil 39, 40 Edge (as cut end face)
42 Negative electrode active material layer 43 (43A, 43B, 43C) Edge (as cut end face)
45, 47 Abrasive water jet device 46, 48 Nozzle 51 Positive electrode plate 54, 64 Insulating coating 61 Negative electrode plate A1, A2 Planned cutting line

Claims (5)

The electrode plates each having an active material layer formed on both surfaces of the metal foil are cut by an abrasive water jet device that jets a high-pressure fluid containing abrasive particles,
In the method of manufacturing a battery having a cutting step of simultaneously forming a cut end surface on each of the active material layer and the metal foil,
A method for manufacturing a battery, comprising forming an insulating coating over the active material layer and the cut end surface of the metal foil by spraying a low-pressure fluid containing insulating particles after cutting the electrode plate.   The battery manufacturing method according to claim 1, wherein the electrode plate is cut by inclining an injection axis of the high-pressure fluid with respect to a plate surface of the electrode plate.   The battery manufacturing method according to claim 1, wherein the insulating particles are alumina.   The method for manufacturing a battery according to claim 1, wherein the abrasive particles are made of the same material as the insulating particles.   The method for manufacturing a battery in a battery according to claim 1, wherein the high-pressure fluid and the low-pressure fluid are N-methyl-2-pyrrolidone (NMP).

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