JP2001345096A - Fabricating apparatus of cell electrode and fabricating method of cell electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a base material having an even thickness in the width direction and suffering from no coating streaks to be coated with 2 layers of an active material layer as an upper layer and a conductive layer as a lower layer at the same time. SOLUTION: The fabricating apparatus of a cell electrode is equipped with a first guide roll 5 for having a current collector 2 travel in a predetermined direction, a second guide roll 6 arranged on the downstream side of the guide roll 5 in the traveling direction of the current collector 2 to have the current collector 2 travel in a predetermined direction together with the first guide roll 5, a nozzle 1 capable of coating the current collector 2 with at least two kinds of coatings at the same time and a support part 108 for maintaining a space between the current collector 2 and the nozzle 1 at a substantially constant interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method which can be used when, for example, an active material paste used in a lithium ion battery, a nickel hydrogen battery or the like is formed on a current collector. The present invention relates to a method for manufacturing a battery electrode for simultaneously forming a conductive layer as an active material layer and a lower layer.

[0002]

2. Description of the Related Art Hitherto, fields where it is necessary to apply a paint on a substrate in multiple layers include, for example, lithium ion batteries and magnetic tapes. It is strongly desired to improve the battery capacity with the application of multi-layer coatings and the recent increase in demand for secondary batteries particularly for lightweight and thin mobile phones and personal computers. The active material paste (hereinafter simply referred to as a paste) for each of the positive electrode plate and the negative electrode plate of the cylindrical or prismatic battery used for these purposes is a few in order to enhance the adhesion between the current collector and the active material layer. % Binder is added.

[0003] However, when a certain amount or more of a binder is added to the paste, the current collector and the active material layer are easily separated from each other due to the effect of migration in a drying step after coating formation, resulting in remarkable cycle characteristics. This is a fatal defect in battery characteristics such as deterioration.

Therefore, in the step of applying the paste, it is necessary to provide a conductive layer between the active material layer and the current collector to form the active material layer and the conductive layer.

A method of manufacturing a battery electrode by simultaneously applying an active material paste and a conductive layer on a current collector is disclosed in Japanese Patent Application Laid-Open No. 9-223499.

[0006] As shown in FIG.
2 is wound around a back roll 201, an extrusion die composed of a plurality of slots is provided at a position facing the back roll 201, and a paste is simultaneously applied onto the current collector 202.

[0007]

However, using a coating means described in Japanese Patent Application Laid-Open No. 9-223499, a paste for a battery as an upper coating and a conductive material as a lower coating are applied to a metal foil (current collector). However, it was found that there was a problem that the thickness of the coating film was large both in the width direction of application and in the running direction of the metal foil, so that it could not be used as a battery electrode plate.

As a result of measuring the coating thickness unevenness in the coating width direction of the sample of the simultaneous two-layer coating obtained by the above-mentioned coating means, it has a large undulation as shown in FIG. 8 (b), and the thickness variation is 15%. Confirmed that there is. There was also a problem that a large number of coating streaks were generated in the coating film.

The reasons for these two problems are as follows.

That is, the reason why the thickness variation of the coating film becomes large is that one of the edges of the downstream lip on the upper layer side and the lower layer side of the extrusion die is displaced from the center of the back roll, so that it occurs on the upstream side of the coating. This is because the remaining liquid pool cannot be stably held. More specifically, the distance between the upper layer of the extrusion die and the back roll cannot be substantially equal to the distance between the lower layer of the extrusion die and the back roll.

The reason why the coating streak is generated is that the gap between the lower lip of the extrusion die and the base material is too small because the lower layer is coated as thinly as possible (1 to 3 μm or less). This is due to foreign matter and the like remaining in the gap between the lip and the base material.

Conventionally, there has been another problem that a paint must be applied to the application surface of a curved substrate.

[0013] The present invention has been made in consideration of the above problems, and
For example, it is an object of the present invention to provide a manufacturing apparatus and a manufacturing method of a battery electrode which can make the thickness of an upper layer paint substantially uniform when two layers of an active material paste and a conductive agent paste are simultaneously formed.

Another object of the present invention is to provide an apparatus and a method for manufacturing a battery electrode which can suppress generation of coating streaks.

Another object of the present invention is to provide an apparatus and a method for manufacturing a battery electrode capable of applying a paint to a substantially flat application surface of a substrate.

[0016]

Means for Solving the Problems The first invention (claim 1)
Corresponds to the first for moving the base material in a predetermined direction.
And a second guide for moving the base material in the predetermined direction together with the first guide roll, the second guide being disposed downstream of the first guide roll in the running direction of the base material. A roll, a nozzle capable of simultaneously applying at least two or more types of paints on the base material, and a support means for maintaining a space between the base material and the tip of the nozzle at a substantially constant space. An apparatus for manufacturing a battery electrode.

According to a second aspect of the present invention (corresponding to claim 2), the support means is means for directly or indirectly supporting the base material. This is an apparatus for manufacturing a battery electrode.

According to a third aspect of the present invention (corresponding to claim 3), the nozzle holds an upper-layer manifold that holds an upper-layer paint among the paints applied on the base material, and a lower-layer paint that holds the lower-layer paint. An upper layer three-way valve that controls supply and stop of the upper layer paint from the upper tank storing the upper layer paint to the upper layer manifold, and / or the lower layer side A lower three-way valve for controlling the supply and stop of the lower paint to the lower manifold from the lower tank storing the paint of the lower paint, and an upper suction and discharge means for sucking and discharging the upper paint in the nozzle, and The battery electrode manufacturing apparatus according to the first or second aspect of the present invention, further comprising: a lower layer suction / discharge means for sucking / discharging the lower layer side paint.

According to a fourth aspect of the present invention (corresponding to claim 4), the first aspect
A method for manufacturing a battery electrode, comprising simultaneously applying at least two or more types of paints on the running base material by using the battery electrode manufacturing apparatus according to any one of claims 1 to 3. .

According to a fifth aspect of the present invention (corresponding to claim 5), among the coatings applied on the base material, the lower coating is a conductive paste, and the upper coating is for a battery electrode. The method for producing a battery electrode according to the fourth aspect of the present invention, which is an active material paste.

A sixth invention (corresponding to claim 6) is the method for manufacturing a battery electrode according to the fifth invention, wherein the conductive paste is an aqueous paste.

According to a seventh aspect of the present invention (corresponding to claim 7), the active material paste contains 0.01 wt% or more and 5 w
5th or 6th feature that the content is not more than t%.
This is a method for producing a battery electrode according to the present invention.

According to an eighth aspect of the present invention (corresponding to claim 8), the conductive paste has a paint viscosity of 0.1 mPa or more and 1000 mPa or less at a shear rate of 1000 (1 / S). Wet thickness 2μm or more 1
The method for producing a battery electrode according to any one of the fifth to seventh aspects of the present invention, wherein the method is applied on the base material so as to have a thickness of 00 μm or less.

According to a ninth aspect of the present invention (corresponding to claim 9), the active material paste for a battery electrode has a shear rate of 1000 (1).
/ S) when the paint viscosity is 1 mPa or more and 10000 mP
a. The method for producing a battery electrode according to any one of the fifth to seventh aspects of the present invention, wherein

According to a tenth aspect of the present invention (corresponding to claim 10),
Among the paints applied on the base material, the paint on the lower layer side is a first active material paste for a battery electrode, and the paint on the upper layer side is a second active material paste for a battery electrode, The first active material paste contains 0.01% of a binder.
The second active material paste contains 0.1% to 30% by weight of a binder.
% Of the battery electrode according to the fourth aspect of the present invention.

According to an eleventh aspect of the present invention (corresponding to claim 11),
A device for manufacturing a battery electrode, comprising at least a nozzle capable of simultaneously applying at least two or more types of paints on a moving base material, and a liquid reservoir forming protrusion, wherein the tip of the nozzle is provided with a Has at least a first lip, a second lip, and a third lip provided in the order from the downstream side to the upstream side in the traveling direction, and the first lip is
A first smoothing section for smoothing a coating surface of the paint discharged from between the first lip and the second lip, wherein the second lip is provided with the second lip; And a second smoothing unit for smoothing a coating surface of the paint discharged from between the third lip and the third lip, wherein the liquid reservoir forming protrusion is provided on the third lip of the nozzle. The second lip is provided on the upstream side and protrudes from the tip of the third lip toward the application surface side of the base material. The tip of the third lip and the protrusion for forming the liquid pool form the second lip. And forming a liquid pool of paint discharged from between the first lip and the third lip.

According to a twelfth aspect of the present invention (corresponding to claim 12),
The tip of the first lip is provided at a position farther from the tip of the third lip with respect to the application surface of the substrate, and the tip of the second lip on the first lip side is A step is formed in the second lip, the step being located closer to the first lip side than the third lip side end, and the step is different from the first lip. A first pool for forming a liquid pool of paint discharged from between the second lip and the second lip;
1 is an apparatus for manufacturing a battery electrode according to the present invention.

A thirteenth aspect of the present invention (corresponding to claim 13) is:
Length L1 of the tip of the third lip of the nozzle from the second lip side end to the liquid reservoir forming protrusion
Is an apparatus for producing a battery electrode according to the eleventh or twelfth aspect of the present invention, which is 0.1 mm or more and 5 mm or less.

The fourteenth invention (corresponding to claim 14) provides:
The length L2 of the second smoothing portion at the tip of the second lip of the nozzle in the direction substantially the same as the running direction of the substrate.
Is an apparatus for producing a battery electrode according to any one of the eleventh to thirteenth aspects, wherein the diameter is 0.1 mm or more and 5 mm or less.

According to a fifteenth aspect of the present invention (corresponding to claim 15),
A length L3 of a tip of the step on the first lip side of the step of the second lip of the nozzle substantially in the same direction as the traveling direction of the base material is 1 mm or more and 5 mm or less. A battery electrode manufacturing apparatus according to any one of the twelfth to fourteenth aspects of the present invention.

According to a sixteenth aspect of the present invention (corresponding to claim 16),
The distance d1 between the tip of the third lip of the nozzle and the tip of the liquid reservoir forming protrusion in a direction substantially perpendicular to the running direction of the base material is 1 μm or more and 100 μm or less. A battery electrode manufacturing apparatus according to any one of the eleventh to fifteenth aspects of the present invention.

The seventeenth invention (corresponding to claim 17) is:
The battery electrode manufacturing apparatus according to any one of the twelfth to sixteenth aspects, wherein a step d2 of the second lip of the nozzle is not less than 20 μm and not more than 500 μm.

The eighteenth invention (corresponding to claim 18) is:
The battery electrode according to any one of the eleventh to seventeenth aspects, further comprising a gap adjusting unit for adjusting a size of a gap between a tip of the first lip and the substrate. Manufacturing equipment.

According to a nineteenth aspect of the present invention (corresponding to claim 19),
An upper block in which the nozzle is composed of the first lip and a part of the second lip on the first lip side, and at least a remainder of the second lip and the third lip. An apparatus for manufacturing a battery electrode according to any one of the eleventh to eighteenth aspects, characterized by comprising a lower block configured.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing the embodiments.

(First Embodiment) FIG. 1 is a schematic diagram of an apparatus for carrying out a method for manufacturing a battery electrode according to a first embodiment of the present invention.

The configuration of an apparatus for implementing the first embodiment according to the present invention will be described.

The nozzle 1 has a support portion 108 for sliding and supporting the coating surface of the current collector 2 and a first lip 1.
05, a second lip 106, a third lip 107, an upper manifold 101 for storing the paste 11, a lower manifold 102 for storing the conductive paste 12, an upper slit 103 for extrusion, and a lower slit 1
04.

Since two layers of the active material layer 3 and the conductive layer 4 are intermittently applied at a predetermined pitch at the same time, the suction device 9,
10 indicates the pistons 901 and 1001 by arrows A or B
Cylinders 902, 1002 for moving in the direction
And jigs 903 and 10 for attaching this to nozzle 1
03 is provided.

The paste 11 and the conductive paste 12 pass through the filters 73 and 83 and the three-way valves 74 and 84 from the tanks 71 and 81 by pumps 72 and 82, respectively.
Upper manifold 101 or lower manifold 10
2, the upper slit 103 and the lower slit 104
Extruded from.

The current collector 2 comprises a support 108 and rolls 5 and 6
And the distance from the tip of the third lip 107 is set to d1.
06 and the first lip 105 are set to d2. In each of these gaps, the upper slit 103,
The paste 11 and the conductive paste 12 extruded from the lower slit 104 flow into the paste pool 1201 of the conductive paste 12.

Then, while forming the paste reservoir 1201, two layers of the active material layer 3 and the conductive layer 4 are simultaneously formed on the current collector 2. Guide rolls 5 and 6
The angle of the current collector 2 with respect to the nozzle 1 can be adjusted. It is preferable that at least the guide roll 6 located on the downstream side of the nozzle 1 is movable in the directions of arrows C and D.

Next, a description will be given of the operation of intermittently forming two layers of the paste 11 for the battery electrode in the upper layer and the conductive paste 12 in the lower layer on the current collector 2 at a predetermined pitch at the same time.

When the application of the paste 11 and the conductive paste 12 is interrupted, the pump 72,
Paste 11 and conductive paste 12 sent from 82
Is simultaneously switched to the return side, and at the same time, the pistons 901 and 1001 are moved in the direction of arrow A. That is, by the switching of the three-way valves 74 and 84, the supply of the paste to the nozzle 1 can be stopped.
01, 1001, the upper slit 10
3. The paste existing in the lower slit 104 and the paste pool 1201 can be sucked. This allows
In particular, the end of the coating is sharpened, and two layers can be simultaneously applied intermittently.

Next, when resuming coating, the three-way valves 74 and 84
Paste 1 sent from pumps 72 and 82
1. The paste supply to the nozzle 1 is restarted by switching the flow of the conductive paste 12 to the supply side, and at the same time, the pistons 901 and 1001 are moved in the direction of arrow B to return the sucked paste 11 to the inside of the nozzle.

By repeating these operations, two layers can be simultaneously and intermittently stabilized at a predetermined pitch.

When two layers of the active material layer 3 and the conductive agent layer 4 are coated simultaneously and continuously on the current collector 2 instead of intermittent coating, the suction devices 9 and 10 and the three-way valves 74 and 84 are used. Needless to say, there is no need to provide them.

Next, the features of the present embodiment will be described in detail.

The feature of the present embodiment is that the nozzle 1 is provided with two or more slits 103 and 104 and a support portion 108 for applying while supporting the current collector 2, and the paste 11 and the This means that the conductive paste 12 is simultaneously applied to the lower layer.

In particular, it is important that the amount of the binder in the active material of the paste 11 for a battery electrode be 0.01 wt% or more and 5 wt% or less. 0.01w of binder in active material
If it is smaller than t%, the adhesion at the interface between the active material layer 3 and the conductive layer 4 becomes too small, which causes a problem of lowering the battery performance. When the amount of the binder in the active material is larger than 5 wt%, two layers of the paste 11 and the conductive paste 12 are applied at the same time, and the density of the active material layer 3 after drying is reduced. There is a problem of deteriorating battery performance.

By setting the amount of the binder in the active material of the paste 11 for a battery electrode in the range of 0.01 wt% or more and 5 wt% or less, as shown in FIG. Since the agents can be uniformly distributed without uneven distribution, the adhesion between the conductive layer 4 and the active material layer 3 can be improved and the density of the active material layer 3 can be kept constant.

When the viscosity at a shear rate of 1000 (1 / S) is η, 0.1 mPa ≦ η ≦ 1000 mPa
It is important that the range of 2 μm ≦ t ≦ 100 μm is satisfied, where t is the wet thickness of the lower conductive paste 12 in the range of 2 μm. When the viscosity at a shear rate of 1000 (1 / S) is η, when the wet thickness of the conductive paste 12 in the range of 0.1 mPa ≦ η ≦ 1000 mPa is smaller than 2 μm, the current between the current collector 2 and the third lip 107 Gap d
Since it is necessary to make 1 extremely small, foreign matter or the like caught in the gap d1 remains and becomes a coating streak.

When the viscosity at a shear rate of 1000 (1 / S) is η, 0.1 mPa ≦ η ≦ 1000 mPa
The wet thickness of the conductive paste 12 in the range of
If it is larger than μm, paste 11 and shear rate 100
When the viscosity of 0 (1 / S) is η, 0.1 mPa ≦ η
The conductive paste 12 having a range of ≦ 1000 mPa is simultaneously applied in two layers, and then the thickness after drying becomes too thick, which causes a problem of lowering the battery performance.

As shown in FIG. 11, when the paint viscosity at a shear rate of 1000 (1 / S) of the upper paste 11 is η, it is important to set the range of 1 mPa ≦ η ≦ 10000 mPa. If the viscosity of the upper paste 11 at a shear rate of 1000 (1 / S) is less than 1 mPa, the surface tension of the paste 11 increases, and the paste 11 cannot mix with the lower conductive paste 12 and mixes. , Two-layer coating cannot be formed. When the paint viscosity at a shear rate of 1000 (1 / S) of the upper paste 11 is greater than 10,000 mPa, the upper manifold 1
The thickness variation in the width direction increases due to the influence of the pressure loss caused by the increase in the pressure of No. 01.

As shown in FIG. 12, when the coating viscosity of the lower conductive paste 12 at a shear rate of 1000 (1 / S) is η, it is important to set the range of 0.1 mPa ≦ η ≦ 1000 mPa. . The coating viscosity of the lower conductive paste 12 at a shear rate of 1000 (1 / S) is 0.1 mP.
If it is smaller than a, the lower layer paste pool 1201 formed at the slit outlet cannot be formed, the application of the conductive paste 12 to the current collector 2 is disturbed, and the thickness of the conductive layer 4 becomes uneven.

When the viscosity of the lower conductive paste 12 at a shear rate of 1000 (1 / S) is greater than 1000 mPa, the pressure of the lower manifold 102 rises as in the case of the upper paste 11 due to the pressure loss. In addition, the thickness variation in the width direction increases.

According to the present embodiment, the upper slit 10
3. paste 11 discharged from lower slit 104;
As a result of coating and forming two layers of the conductive paste 12 on the current collector 2 at the same time, as shown in FIG. 8A, a coating streak is suppressed and a battery electrode plate having a uniform thickness in the width direction is formed. Was completed.

In the above-described first embodiment, the support portion 108 is used as an example of the support means or the liquid reservoir formation convex portion of the battery electrode manufacturing apparatus of the present invention.

(Second Embodiment) FIGS. 2 and 3 are schematic views of a battery electrode manufacturing apparatus according to a second embodiment of the present invention.

Since the configuration of the apparatus for carrying out the second embodiment according to the present invention is the same as that of the first embodiment, the description of the parts having the same functions will be omitted.

In this embodiment, as shown in FIG. 2, the tip of the nozzle 1 has a first lip 105 from the downstream side, an upper slit 103 serving as an outlet for the upper paint, a second lip 106,
A lower slit 104 serving as an outlet for the lower paint, and a third slit 104
The lip 107 is configured.

The first lip 105 has an upper layer smooth portion 1051 for smoothing the upper layer paint application surface, and the second lip 106 has an lower layer smooth portion for smoothing the lower layer paint application surface. 1062, and an upper liquid reservoir 1061 for forming a liquid reservoir of the upper paint.
The lip 107 has a support portion 1072 for supporting the base material (current collector) 2 and a lower layer liquid reservoir 1071 for forming a liquid layer of the lower layer paint.

The features relating to the details of this embodiment are shown in FIG.
3 will be described below.

The first feature is that the space between the support portion 1072 and the lower liquid reservoir 1071, that is, the step d 1, the top of the lower smooth portion 1062 and the upper liquid reservoir 1062.
1 and a portion of the step d2 with the upper slit 103
And forming the pools 1101 and 1201 of the paste 11 and the conductive paste 12 respectively discharged from the lower slit 104 and simultaneously applying two layers on the current collector 2.

By forming the paste reservoirs 1101 and 1201, even if the current collector 2 slightly fluctuates in the nozzle direction, the thickness of the active material layer 3 and the conductive layer 4 can be made uniform without disturbing the application. It can be. Furthermore, pressure can be applied to the lower portion of the paste reservoir 1201 by the upper layer of the reservoir 1101, and an extremely thin conductive layer 4 can be obtained.

The second characteristic is that when the length from the lower end of the exit of the lower slit 104 to the top of the support 1072 along the substrate running direction is L1, 0.1 mm ≦ L1
It is important to keep the range of ≦ 5 mm. L1 is 0.1
If it is smaller than mm, the paste pool 1201 formed at the exit of the slit 104 cannot be formed, the application of the conductive paste 12 to the current collector 2 is disturbed, and the thickness of the active material layer 3 and the conductive layer 4 becomes uneven. . When L1 is larger than 5 mm, wrinkles are likely to be formed in the current collector 2 in the width direction at the slit exit, and the thickness variation in the width direction of the active material layer 3 and the conductive layer 4 increases.

When the length of the lower layer smooth portion 1062 along the substrate running direction is L2, 0.1 mm ≦ L2 ≦ L2
A range of 5 mm is extremely important when two layers of the paste 11 and the conductive paste 12 are applied simultaneously.

When L2 is smaller than 0.1 mm, the pressure from the upper-side paste pool 1101 is easily received, and the pressure on the lower-layer paste pool 1201 becomes too large. Layers cannot be applied simultaneously. If L2 is larger than 5 mm, the pressure from the upper-side paste reservoir 1101 is not applied, and the thickness of the conductive layer 4 cannot be reduced.

When the length of the upper liquid reservoir 1061 along the substrate running direction is L3, 1 mm ≦ L3 ≦
A range of 5 mm is extremely important when two layers of the paste 11 and the conductive paste 12 are applied simultaneously.

When L3 is smaller than 1 mm, the slit 1
In addition to not being able to form the paste pool 1101 formed at the outlet 03, the pressure on the lower paste pool 1201 becomes too large, and the paste 11 and the conductive paste 1
Cannot be simultaneously applied in two layers. Also, L3
Is larger than 5 mm, the lower side of the paste pool 12
01 cannot be applied to the conductive layer 4
Cannot be applied thinly, which causes a problem of lowering battery performance.

The third feature is that when a step between the tangent line at the top of the support portion 1072 and the lower layer liquid reservoir 1071 is d1, it is important that the range is 1 μm ≦ d1 ≦ 100 μm.

When d1 is smaller than 1 μm, the pressing force of the current collector 2 against the paste reservoir 1201 becomes too strong, so that the paste reservoir 1201 cannot be formed stably and the thickness of the active material layer 3 and the conductive layer 4 Becomes non-uniform. When d1 is larger than 100 μm, the pressing force of the current collector 2 against the paste pool 1201 is too small to form the paste pool 1201 stably, and the thickness of the active material layer 3 or the conductive layer 4 is reduced. In this case, it is not uniform.

When the step between the tangent line at the top of the lower smoothing portion 1062 and the upper liquid reservoir 1061 is d2, it is important to set the range of 20 μm ≦ d2 ≦ 500 μm.

When d2 is smaller than 20 μm, the pressing force of the current collector 2 against the paste pool 1101 becomes too strong to form the paste pool 1101 formed at the exit of the slit 103. The pressure becomes too large, so that the paste 11 and the conductive paste 12 cannot be simultaneously applied in two layers. When d2 is larger than 500 μm, the pressing force of the current collector 2 against the paste reservoir 1201 is too small to form the paste reservoir 1201 stably, and the thickness of the active material layer 3 becomes uneven.

Within the scope of the present embodiment, paste 1 discharged from upper slit 103 and lower slit 104
1. As a result of simultaneously applying and forming two layers of the conductive paste 12 on the current collector 2, as shown in FIG. 8A, a battery electrode plate having a uniform thickness in the width direction and an extremely thin conductive layer 4 is prepared. I was able to do it.

Next, a specific example of this embodiment will be described.

The nozzle 1 is shown in FIG. 2, and d1 = 20
μm, d2 = 200 μm, L2 = 1 mm, upper slit gap G = 0.5 mm, lower slit gap G =
0.2 mm and an application width of 480 mm. The length from the lower end of the exit of the lower layer slit 104 to the top of the support portion 1072 along the substrate running direction is 0.05 to 10 mm.
And the upper liquid pool 1061
The length along the substrate running direction is 0.5 mm to 10 mm
Was changed within the range. The paste viscosity of each of the following negative electrode and positive electrode was 1000 mPa, and the anchor paste was 1 mPa.

As the negative electrode, a current collector was a copper foil having a thickness of 10 μm and a width of 500 mm, and a paste for the negative electrode was prepared by kneading a carbon material, CMC and water. As the anchor agent, a mixture obtained by kneading and dispersing a conductive carbon black, a binder and water was used. First, two layers of the active material layer and the conductive layer were intermittently formed on the current collector intermittently at a predetermined pitch of 300 to 400 mm according to the present embodiment, and dried.

As the positive electrode, the current collector was an aluminum foil having a thickness of 20 μm and a width of 500 mm, and the positive electrode paste was LiCo.
O ₂ , conductive carbon black, fluorine resin, CMC
And water kneaded. The anchor agent was the same as that used for the negative electrode. First, two layers of the active material layer and the conductive layer were intermittently formed on the current collector intermittently at a predetermined pitch according to the present embodiment, and then dried.

After the obtained positive and negative electrode plates were rolled to a predetermined thickness, they were slit to a predetermined width to prepare a lithium ion secondary battery. As a comparative example, the same intermittent coating was performed by a conventional intermittent coating device. The obtained positive electrode and negative electrode plates were rolled to a predetermined thickness, and then slit to a predetermined width to prepare a lithium ion secondary battery of a comparative example.

The following evaluation was performed on the electrode plate and the battery after the coating and drying, and the effect of the present embodiment was confirmed.

(1) Variation in thickness of active material layer 3
Measurements were made at points, and the difference between the maximum thickness and the minimum thickness with respect to the average thickness was evaluated as thickness variation. Table 1 shows the results.
Are shown together.

[0083]

[Table 1] Within the range of the present embodiment, the thickness variation can be obviously reduced, and it can be seen that the battery electrode plate is good.

(2) Discharge capacity At room temperature, a secondary battery that has been charged at a constant current (160 mA) and a final voltage (4.2 V) is discharged at a constant current (160 mA to 3200 mA) and decreases from the start of discharge. The comparison was made based on the discharge capacity when the applied voltage reached the final voltage (3 V). FIG. 9 shows the results. The battery according to the present embodiment clearly has a higher discharge capacity than the battery according to the conventional example.

(3) Cycle characteristics Constant conditions at normal temperature (discharge: current 1900 mA, final voltage 3 V, charging: current 160 mA, final voltage 4.2 V)
The charge / discharge was repeated to measure the discharge capacity, and the comparison was made based on the number of times of charge / discharge (cycle) when the discharge capacity reached 90% of the initial discharge capacity. The results are shown in FIG. The battery according to the present embodiment has clearly improved cycle characteristics as compared with the battery according to the conventional example.

As a result of the above evaluation, the effects of this embodiment will be described below.

First, by providing the steps d1 and d2 while supporting the current collector 2 with the support portion 1072, the paste 11 and the conductive paste 12 are simultaneously formed while the paste reservoirs 1101 and 1201 are formed stably. Since the layers can be coated, a battery electrode plate having a uniform thickness in the width direction and a reduced coating streak can be obtained, so that the product yield can be significantly improved.

Second, when the length of the lower layer smooth portion 1062 along the substrate running direction is L2, 0.1 mm ≦ L2
≦ 5 mm, when the length of the upper layer liquid reservoir 1061 along the substrate running direction is L3, 1 mm ≦ L3 ≦ 5
mm, the upper layer of the paste pool 110
1 is stably formed, and the lower layer paste pool 12
Since the pressure is applied to 01 and the thickness of the conductive layer 4 can be applied extremely thinly, the battery electrode plate is provided with flexibility, and the active material layer 3 and the conductive layer 4 are entangled with each other. The strength could be increased, and the productivity and product yield could be significantly improved.

Third, by providing the conductive layer 4 between the current collector 2 and the active material layer 3, the adhesion between the current collector 2 and the conductive layer 4, and between the conductive layer 4 and the active material layer 3 can be improved. Since the properties can be improved, the amount of the binder in the active material can be significantly reduced, and therefore, there is no influence of migration during drying, and the cycle characteristics can be improved. further,
At the same time, the density of the active material layer 3 was improved. As a result, the discharge capacity of the battery prepared in the present embodiment was able to be significantly improved.

(Third Embodiment) FIGS. 4 to 6 are schematic views of a battery electrode manufacturing apparatus according to a third embodiment of the present invention.

In this embodiment, the upper block 1 of the nozzle 1
It relates to the adjustment of the gap between 111 and the current collector 2,
Otherwise, the configuration is the same as that of the second embodiment, and the other configuration can be the same as that of the second embodiment, and the description is omitted here.

The feature of this embodiment is that, as shown in FIG. 4, the nozzle 1 is composed of a divided upper block 1111 and a lower block 1112, The point is that an adjusting means 1009 is provided.

That is, as shown in FIG. 6, the nozzle 1 slides on the application surface side of the current collector 2 and supports the support 1072, the third lip 107 and the upstream second lip 106.
And lower block 1112 fastened with fixing screws 109
An upper block 1111 in which the first lip 105 and the downstream second lip 1063 are fastened with fixing screws 118, an upper manifold 101 which is a reservoir for the paste 11, and a lower manifold 102 which is a reservoir for the conductive paste, and for extrusion. The upper block 1111 and the lower block 1112 are fastened with fixing screws 110, and the nozzle 1 is fastened to the stage 1007 with the fixing screws 111.

Further, as shown in FIG.
8 is fastened to the center of the back plate of the table 1007 and to the back of the upper block 1111 of the nozzle 1. The pivoting means 1008 not only pivots the upper block 1111 in a pendulum shape, but also pivots with the pivoting means 1008 and the upper block 111.
In order to prevent the displacement of the upper block 1111 that occurs when the fixing screw 111 that fastens the upper block 1111 and the lower block 1112 is loosened when adjusting the gap of the step d2 because the first block 1 is fixed. It is in.

The position adjusting mechanism 1000 of the nozzle 1 shown in FIG. 4 is not particularly limited here,
For example, it comprises an air cylinder 1113, a guide 1005 fixed on a base 1006, and a stopper 1004. When adjusting the gap d1 of the upper block 1111,
After loosening the fixing screw 110 fixing the upper block 1111 and the lower block 1112, the gap adjusting means 10 fastened to both sides of the upper block 1111 of the nozzle 1
In step 09, the gap d1 is set while reading the dial gauge 1010.

By using the device according to the present embodiment,
A battery electrode plate having a uniform thickness in the width direction can be obtained.

Therefore, in the present embodiment, the same effects as in the second embodiment can be obtained.

(Fourth Embodiment) FIG. 7 is a schematic view of an apparatus for carrying out a method for manufacturing a battery electrode according to a fourth embodiment of the present invention.

The present embodiment is characterized in that the nozzle 1 is provided with two slits 103 and 104 and a supporting portion 1072 for applying while supporting the current collector 2, and the amount of the binder in the active material is formed in the upper layer. Material paste 11 in which the content of the binder was 0.1% or more and 30% or less, and the amount of the binder in the active material was 0.01% in the lower layer.
% Of the active material paste 12 in the range of not less than 10% and not more than 10%, and the other configuration can be the same as that of the second embodiment, and the description is omitted here.

In this embodiment, the upper slit 10
It is important that the amount of the binder in the active material extruded from No. 3 be in the range of 0.1% or more and 30% or less. If the amount of the binder in the active material is smaller than 0.1%, the adhesion to the lower active material layer 4 is extremely reduced, and the active material layer 3 is easily peeled off, which causes a problem of lowering the battery performance. . Further, when the amount of the binder in the active material is larger than 30%, the density of the active material layer 3 becomes small, and in this case, there is a problem that the battery performance is reduced.

It is important that the amount of the binder in the active material extruded from the lower slit 104 is in the range of 0.01% to 10%. If the amount of the binder in the active material is smaller than 0.01%, the adhesion between the current collector 2 and the active material layer 4 is extremely reduced, and the active material layer is remarkably dropped off, resulting in poor product quality. Fatal problems arise. Further, when the binder in the active material is larger than 10%, the density of the active material layer 4 becomes small, and thus a problem that battery performance is lowered occurs.

Within the scope of the present embodiment, in particular, the total thickness of active material layers 3 and 4 in the width direction can be made uniform.

Therefore, in the present embodiment, the same effects as in the second embodiment can be obtained.

[0104]

As is apparent from the above description, the present invention is directed to a battery electrode in which the upper layer paint and the lower layer paint are formed in two layers at the same time on the substrate and the thickness of the upper layer paint is made substantially uniform. A manufacturing apparatus and a manufacturing method can be provided.

Further, the present invention can provide an apparatus and a method for manufacturing a battery electrode which suppress generation of coating streaks.

Further, the present invention can provide an apparatus and a method for manufacturing a battery electrode in which a paint is applied to a substantially flat application surface of a substrate.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a manufacturing apparatus according to a second embodiment of the present invention;

FIG. 3 is a schematic configuration diagram for explaining a tip shape of a nozzle 1 according to a second embodiment.

FIG. 4 is a schematic configuration diagram illustrating a manufacturing apparatus according to a third embodiment of the present invention.

FIG. 5 shows a position adjusting mechanism 10 according to a third embodiment.
Schematic configuration diagram for explaining 00

FIG. 6 is a schematic configuration diagram showing a nozzle 1 according to a third embodiment.

FIG. 7 is a schematic configuration diagram illustrating a manufacturing apparatus according to a fourth embodiment of the present invention.

8A is a cross-sectional view of a coating film according to the first embodiment. FIG. 8B is a cross-sectional view of a coating film according to a conventional example.

FIG. 9 is a diagram for explaining a measurement result of a discharge capacity in the first to fourth embodiments.

FIG. 10 is a view for explaining measurement results of cycle characteristics in the first to fourth embodiments.

FIG. 11 is a view showing the rheological properties of the upper coating material used in the present embodiment.

FIG. 12 is a diagram showing the rheological properties of the lower coating material used in the present embodiment.

FIG. 13 is a schematic configuration diagram showing an apparatus according to a conventional example.

FIG. 14 is a configuration diagram of a battery electrode plate according to the first embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 nozzle 2 current collector 3 active material layer 4 conductive layer 5 roll 6 roll 7 upper supply system 8 lower supply system 9 suction device 10 suction device 11 paste 12 conductive paste 71 tank 72 pump 73 filter 74 three-way valve 101 upper manifold 101 102 Lower layer manifold 103 Upper layer slit 104 Lower layer slit 105 First lip 106 Second lip 107 Third lip 108 Support section 109 Fixing screw 110 Fixing screw 111 Fixing screw 118 Fixing screw 901 Piston 902 Air cylinder 903 Jig 1000 Position adjusting mechanism 1001 Piston 1002 Air cylinder 1003 Jig 1003 1004 Stopper 1005 Guide 1006 Base 1007 Table 1008 Rotating means 1009 Gap adjusting means 1010 Dial gauge 11 Reservoir 1 upper block 1112 the lower block 1113 air cylinder 1051 upper smooth section 1061 upper liquid reservoir portion 1062 underlying smooth portion 1063 downstream second lip 1064 upstream second lip 1071 lower solution reservoir 1072 supporting portion 1101 paste reservoir 1201 paste

Continuing on the front page (72) Inventor Takao Kuromiya 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5H050 AA19 BA02 BA05 BA14 BA17 CA03 CA08 CB07 CB16 DA04 DA10 DA11 FA02 GA22 GA29 HA01 HA04 HA20

Claims (19)

[Claims] 1. A first guide roll for running a base material in a predetermined direction, and a first guide roll disposed downstream of the first guide roll in a running direction of the base material, and a first guide roll together with the first guide roll. A second guide roll for running the base material in the predetermined direction; a nozzle capable of simultaneously applying at least two or more types of paints on the base material; and a base end of the base material and the nozzle And a support means for maintaining a substantially constant interval with the battery electrode. 2. The apparatus for manufacturing a battery electrode according to claim 1, wherein said supporting means is means for directly or indirectly supporting said base material. 3. The nozzle includes an upper manifold that holds an upper paint layer, and a lower manifold that holds a lower paint layer, among the paints applied on the base material. An upper three-way valve for controlling the supply and stop of the upper layer paint from the upper tank storing the paint to the upper manifold, and / or the lower layer storing the lower layer paint from the lower tank; A lower three-way valve for controlling the supply and stop of the lower layer paint to the manifold; an upper layer suction / discharge means for sucking / discharging the upper layer paint in the nozzle; and / or a lower layer exhaust / discharge for sucking / discharging the lower layer paint. 3. The apparatus for manufacturing a battery electrode according to claim 1, further comprising: means. 4. A battery electrode according to claim 1, wherein at least two or more kinds of paints are simultaneously applied on the running base material using the battery electrode manufacturing apparatus according to claim 1. Production method. 5. The paint applied on the substrate, wherein the paint on the lower layer side is a conductive paste, and the paint on the upper layer side is an active material paste for a battery electrode. 5. The method for producing a battery electrode according to item 4. 6. The method according to claim 5, wherein the conductive paste is an aqueous paste. 7. The active material paste contains a binder in an amount of 0.1 to 10.
The method for producing a battery electrode according to claim 5, wherein the content of the battery electrode is not less than 01 wt% and not more than 5 wt%. 8. A shear rate of the conductive paste of 1000.
The paint viscosity at (1 / S) is 0.1 mPa or more and 100
The method for producing a battery electrode according to any one of claims 5 to 7, wherein the conductive paste is applied to the base material at a pressure of 0 mPa or less and the wet thickness is 2 µm or more and 100 µm or less. . 9. The paint viscosity at a shear rate of 1000 (1 / S) of the active material paste for a battery electrode is 1 mPa.
The method for producing a battery electrode according to any one of claims 5 to 7, wherein the pressure is not less than 10,000 mPa. 10. The paint applied on the substrate,
The lower-layer paint is a first active material paste for a battery electrode, and the upper-layer paint is a second active material paste for a battery electrode. 0.01wt of adhesive
5. The battery electrode according to claim 4, wherein the second active material paste contains 0.1 to 30 wt% of a binder. Production method. 11. An apparatus for manufacturing a battery electrode, comprising at least a nozzle capable of simultaneously applying at least two or more types of paints on a moving base material, and a liquid reservoir forming projection, wherein a tip of the nozzle is provided. Has at least a first lip, a second lip, and a third lip provided in the order from the downstream side to the upstream side in the traveling direction of the base material, and the first lip is A first smoothing unit for smoothing a coating surface of the paint discharged from between the first lip and the second lip, wherein the second lip includes the second lip and the second lip; A second smoothing unit for smoothing a coating surface of the paint discharged from between the third lip and the third lip of the nozzle; On the side of the third lip, and the coating of the substrate is more than the tip of the third lip. Protrudes on the side, at the tip and the liquid reservoir forming protrusions of the third lip,
An apparatus for manufacturing a battery electrode, wherein a liquid pool of paint discharged from between the second lip and the third lip is formed. 12. The tip of the first lip is connected to the third lip.
The tip of the second lip is closer to the first lip side than the tip of the third lip side. The step is formed on the second lip, which is located closer to the tip on the first lip side, and the step is discharged from between the first lip and the second lip. The apparatus for manufacturing a battery electrode according to claim 11, wherein the apparatus is for forming a liquid pool of paint. 13. A length L1 of the tip of the third lip of the nozzle from the end of the second lip to the protrusion for forming a liquid pool is 0.1 mm or more and 5 mm or less. The battery electrode manufacturing apparatus according to claim 11 or 12, wherein 14. A length L2 of the tip of the second lip of the nozzle in a direction substantially the same as a traveling direction of the base material of the second smoothing portion is 0.1 mm or more and 5 mm or less. The battery electrode manufacturing apparatus according to any one of claims 11 to 13, wherein: 15. A length L3 of a tip of the step of the second lip of the nozzle on the first lip side in a direction substantially the same as a running direction of the base material is 1 mm or more and 5 mm or less. The apparatus for manufacturing a battery electrode according to any one of claims 12 to 14, wherein: 16. A tip of said third lip of said nozzle in a direction substantially perpendicular to the direction of travel of said substrate;
The apparatus for manufacturing a battery electrode according to any one of claims 11 to 15, wherein a distance d1 from a tip of the liquid reservoir forming protrusion is 1 µm or more and 100 µm or less. 17. The apparatus according to claim 12, wherein a step d2 of the second lip of the nozzle is not less than 20 μm and not more than 500 μm. 18. The battery according to claim 11, further comprising a gap adjusting means for adjusting a size of a gap between a tip of the first lip and the base material. Electrode manufacturing equipment. 19. An upper block including the first lip and a part of the second lip on the first lip side, the remaining portion of the second lip, and the third lip.
19. The apparatus for manufacturing a battery electrode according to claim 11, wherein the apparatus comprises a lower block including at least a lip.