JPH11120994A - Electrode having interleaf film and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an uniform electrode surface layer to improve the quality, strength and flexibility of an electrode by using, as an interleaf film to be integrally connected to an electrode active material layer, an interleaf film consisting of nonwoven polypropylene and having a means for promoting the polymerization of the active material layer. SOLUTION: A battery 70 is formed of a first electrode 72, an electrolyte 74, and a second electrode 76, and the first electrode 72 is formed of a current collecting base plate 78, an electrode active material 80 and an interleaf film 82 integrally connected to the electrode active material 80. The interleaf film 82 is formed of nonwoven polypropylene (nonwoven span bonded polypropylene), and the interleaf film 82 is impregnated with a polymerization initiator prior to the applying process of the electrode active material paste to the current collecting base, whereby uniformity in polymerization of the electrode active material can be improved. The interleaf film 82 is permanently connected to the electrode active material 80, whereby the tensile strength and flexibility of a manufactured electrode material are increased, so that the resistance to crack and/or breakage in rolling or bending of an electrode can be imparted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrode having an interleaf film and a method for producing the same, and more particularly, to an electrode having an interleaf film containing an electrode active material.

[0002]

BACKGROUND OF THE INVENTION Batteries having a current collecting substrate made of a polymerizable electrode active material have been known in the art for several years. It is also well known that the interleaf film can be temporarily bonded to the surface of the electrode active material during the manufacturing process.

Although the polymerizable electrode active material can be said to be functionally usable, it has problems related to the quality, strength and flexibility of the electrode, particularly problems due to the manufacturing process. For example, in a conventional interleaf material, the pressure of a roller is usually applied in a curing furnace to cause slippage, and as a result, the electrode active material adheres unevenly to the current collecting substrate. Further, when such pressure is applied, the electrode active material usually moves around the interleaf material and adheres to the rollers of the curing furnace. When the electrode active material adheres to the roller, any subsequent electrode active material exposed to the roller is damaged by the uneven surface of the contaminated roller. In addition, the transfer of such materials can damage the rollers, resulting in the need to stop the device and replace the rollers.

When the interleaf material is removed during the manufacturing process, a portion of the electrode active material adheres to the interleaf material, thereby forming a non-uniform electrode surface layer. Such non-uniformity of the electrode surface layer deteriorates the mechanical characteristics and cycle performance of the manufactured battery.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to form a uniform electrode surface layer without contaminating and damaging the roller with an electrode active material in a manufacturing process of an electrode material.
An object of the present invention is to provide an electrode having an interleaf film and a method for manufacturing the electrode, in which problems relating to the quality, strength, and flexibility of the electrode have been solved.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, an electrode active material has been used instead of an interleaf film which has been temporarily used in the production of an electrode. It has been found that the above object can be achieved by using an interleaf film that is integrally bonded to a layer.

The present invention has been completed based on the above findings, and a first gist thereof is for a battery comprising a current collecting substrate, an electrode active material layer, and an interleaf film integrally bonded to the active material layer. Exists on the electrodes.

[0008] In a preferred embodiment of the first aspect, the integral interleaf membrane comprises a non-woven polypropylene that binds at least a portion of the electrode active material.

In another preferred embodiment of the first aspect,
The integrated interleaf film has a means for promoting polymerization of the active material layer. As the polymerization accelerating means, the integral type interleaf film is impregnated with a polymerization initiator capable of binding to the interleaf film.

In another preferred embodiment of the first aspect,
The electrode has means for fixing the polymerizable electrolyte to the active material layer. The electrolyte fixing means is an integrated interleaf film having a portion extending above the active material layer, and the extended portion can cooperate integrally with the electrolyte.

In another preferred embodiment of the first aspect,
The electrode has means for promoting the movement of ions through the interleaf membrane. The ion transfer promoting means is an integrated interleaf film having permeability for predetermined ions. In addition, an interleaf membrane may be used as a means to increase the tensile strength and flexibility of the electrode.

A second aspect of the present invention resides in a battery electrode comprising a current collecting substrate, an electrode active material layer, and an interleaf film containing a polymerization initiator and bonding to the electrode active material layer.

A third aspect of the present invention is a battery comprising an electrolyte, a first electrode, and a second electrode, wherein at least one of the first electrode and the second electrode includes a current collecting substrate, an electrode active material layer, An interleaf film integrally bonded to an active material layer, wherein the interleaf film extends continuously from at least a portion of the active material layer and penetrates at least a portion of the electrolyte.

[0014] A fourth aspect of the present invention is a step of attaching a polymerizable active material layer to the surface of a current collecting substrate; a step of integrally bonding an interleaf film to at least a portion of the polymerizable active material layer; Bonding an initiator to the polymerizable active material layer; and at least partially curing the active material layer.

[0015] In a preferred embodiment of the fourth aspect of the present invention, the polymerization initiator is bonded to the interleaf film before the step of integrally bonding the interleaf film into at least a part of the electrode active material. In this preferred embodiment, the step of binding the polymerization initiator includes a step of impregnating the interleaf film with the polymerization initiator.

[0016] In another preferred embodiment of the fourth aspect of the present invention, the step of at least partially curing the electrode active material comprises the steps of: applying ultraviolet light, infrared light, a thermal energy beam, and an electron beam to the electrode active material and the polymerization initiator. Curing by exposing to at least one of

According to a fifth aspect of the present invention, a step of applying a polymerizable active material layer to the surface of a current collecting substrate; a step of integrally bonding an interleaf film to at least a portion of the polymerizable electrode active material layer; Bonding a polymerization initiator to the polymerizable active material layer; at least partially curing the active material layer; bonding an electrolyte to the at least partially cured electrode active material; adjacent to the electrolyte Bonding the second electrode.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The most important feature of the present invention is that an interleaf film which is integrally bonded to an electrode active material layer is used instead of an interleaf film which has been temporarily used in the manufacture of a battery. However, by incorporating an interleaf film in the electrode, the problem that arises in the production of the electrode material and the problem of the performance of various electrodes caused by the problem are solved. Hereinafter, the present invention will be described with reference to the drawings.
It should be noted that the present invention is capable of a wide variety of embodiments,
The present invention is not limited to the following embodiments.

FIG. 1 is a schematic diagram of a prior art battery. Battery 10 includes a first electrode 12, an electrolyte 14, and a second electrode 16
Consists of Further, the first electrode 12 includes a current collecting substrate 18 and an electrode active material 20, and the second electrode 16 includes a current collecting substrate 22 and an electrode active material 24. As can be readily seen from FIG. 1, in a prior art battery, a first electrode 12 and a second electrode 16 were used.
Has no relevance to the interleaf film.

FIG. 2 is a schematic view of a conventional method for manufacturing a battery electrode. As shown in FIG. 2, the prior art method of manufacturing an electrode consists of several separate but interdependent steps. Electrode paste pump 30
Mixes and / or holds the electrode paste, ie, the electrode active material, which is then pumped to a mixer 32 where the polymerization initiator is added. The mixture of the electrode active material and the polymerization initiator is subsequently pumped to the application head 34 to deposit a predetermined amount of the electrode active material / polymerization initiator on the surface 36 of the current collecting substrate 18.

As an alternative method, a method is known in which the electrode active material is applied to the surface 36 of the current collecting substrate 18 and then the polymerization initiator is delivered using the initiator holding container 40 and the initiator wick 42. I have.

After the mixture of the electrode active material and the polymerization initiator is placed on the current collecting substrate, the conventional interleaf 44 is placed in the curing furnace 46 on the mixed and applied electrode active material. It is applied just before placing. The laminate of current collector substrate 18, electrode active material / polymerization initiator, and conventional interleaf 44 passes through a series of rollers 48 in curing oven 46. Therefore, some problems occur, that is, a mechanical defect of the electrode active material occurs due to the accidental sliding and / or movement of the conventional interleaf, and the uniformity of the electrode active material on the current collecting substrate changes. . Furthermore, the conventional interleaf is pressed onto the electrode active material by the roller 48, so that an undesirable amount of the electrode active material adheres to the roller 48. If the amount of the electrode active material on the roller 48 is too large, not only does the production of the electrode be adversely affected, but also the roller 48 is damaged.

Electrode active material that has just been "cured" (in the art, the term "cured" refers to the use of an electrode active material and a polymerization initiator, such as at least one of ultraviolet, infrared, thermal energy, and electron beam). Including at least partially polymerizing the electrode active material by exposure to
After exiting the curing oven 46, it is collected by the electrode receiving rollers 52. Almost at the same time, the take-up reel 50
The interleaf 44 is removed from the cured (or partially cured) electrode active material of the electrode. When the take-off reel 50 removes the conventional interleaf 44 from the manufactured electrode, a portion of the electrode active material actually adheres to the bottom surface 51 of the conventional interleaf, thereby providing a uniform surface of the electrode active material. The properties and mechanical integrity are adversely affected, and consequently the electrodes.

FIG. 3 is a cross-sectional view of the electrode active material layer applied on the current collecting substrate in the prior art, and shows a non-uniform surface of the electrode active material generated by the prior art electrode manufacturing method. The irregular surface 60 of the cured electrode active material 20 on the current collector substrate 18 not only reduces the mechanical and electrochemical integrity of the electrode, but also promotes the formation of dendrites, increasing the electrical resistance of the battery. And short-circuiting of the battery occurs early.

FIG. 4 is a schematic diagram of the battery of the present invention. The battery 70 of the present invention includes a first electrode 72, an electrolyte 74, and a second electrode 76. The first electrode 72 further includes a current collecting substrate 7.
8, an electrode active material 80, and an interleaf film 82 integrally bonded. The second electrode 76 further includes a current collecting substrate 84 and an electrode active material 86. Although not shown in this embodiment, the second electrode 76 may be combined with an interleaf film. As the current collecting substrate 78, a conventional current collecting material such as aluminum, nickel, copper, and lithium can be used.

In the present invention, the first electrode active material 80 is formed by applying an electrochemically active compound, an electrochemically conductive additive, and an ion conductive polymer to the first current collecting substrate 78, and then forming a part thereof. And / or by polymerizing all. As the electrochemically active compound, lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide,
Or, oxides of other lithium transition metals, and the like,
Examples of the electrochemically conductive additive include carbon and graphite. Of course, known electrode active materials other than those exemplified here can also be used. This is the same for the second electrode active material 86 and the electrolyte 74.

The interleaf film 82 bonded together is
Preferably, non-woven polypropylene (non-woven spun bonded polypropylene, PGI Non-Woven Inc.
(Westchester, Pa.) Or Ahlstrom Filtration I
nc. (Mount Holly S, Pennsylvania
(Prings). Non-woven polypropylene is porous and its thickness is relatively thin, so that certain ions can move through the interleaf membrane. As a material of the interleaf film, other than the non-woven polypropylene, a material that is chemically inert to the remaining part of the battery to be finally bonded, and for increasing the tensile strength and flexibility of the electrode. Other materials that can be used as a means may be used.

FIG. 5 is a schematic view of a method for manufacturing a battery electrode of the present invention, FIG. 6 is a schematic view of an interleaf film of the present invention impregnated with a polymerization initiator, and FIG. 7 is a cross section of the electrode according to the present invention. The figures are shown respectively. As shown in FIG.
And a method of manufacturing an electrode such as the first electrode 72 of FIG. The manufacturing method of the present invention will be described with reference to FIG. In the electrode manufacturing method of the present invention, an electrode paste pump for supplying a predetermined amount of electrode paste, that is, an electrode active material, into the mixer 102, that is, an electrode active material pump 1
00. After being mixed in the mixer 102, the electrode active material is transported to the coating head 104. The electrode active material supplied from the coating head 104 is attached to the surface 106 of the current collecting substrate 78 supplied from the current collecting roller 110. After the electrode active material is applied to the surface 106 of the current collecting substrate 78, the interleaf film 82 supplied from the interleaf roller 109 is combined with the electrode active material.

In a preferred embodiment of the present invention, as shown in FIG. 6, the interleaving film 82 is impregnated with the polymerization initiator 160 before the step of coating the electrode active material paste / current collector substrate. Since the polymerization initiator is impregnated into the interleaf film, the uniformity of polymerization of the electrode active material is improved.

In another preferred embodiment, the second interleaf film 111 (shown in dashed lines in FIG. 5) is applied to the upper surface 82 ′ of the first interleaf film 82 which has already been laminated. (Indicated by a broken line in FIG. 5). After passing through the inside of the curing furnace 112, the second interleaf film 111 is removed by the take-off roll 136, but as shown in FIG. 7, the interleaf film 82 bonded to the electrode active material 80 becomes the first interleaf film 82.
It remains on the electrode 72. Since the interleaf film 82 is permanently bonded to the electrode active material, the tensile strength and flexibility of the manufactured electrode material are increased, and resistance to cracking and / or breaking during rolling or bending of the electrode is provided. .

After laminating the interleaf film 82 on the electrode active material 80, the laminate composed of the current collecting substrate 78, the electrode active material 80, and the interleaf film 82 is transported to a curing furnace 112, where the electrode active material 80 At least partially is promoted. In the curing furnace, the current collecting substrate 78,
The laminate composed of the electrode active material 80 and the interleaf film 82 passes through a series of rollers 132. These rollers 132 have a function of maintaining an appropriate tension of the current collecting material in order to promote the uniformity of the electrode active material 80 and the current collecting material 78 particularly during curing. Although a curing oven 112 has been described herein for performing the curing, other conventional curing methods (curing methods commonly understood by those skilled in the art) can be used as well.

The manufactured first electrode 72 is supplied to a curing furnace 112.
Is wound up in a roll shape by the electrode take-up reel 130. The roll of electrode material is stored or used to provide further post-production steps to produce a finished battery. FIG. 8 shows a cross-sectional view of the electrode of the present invention combined with an electrolyte. When the post-manufacturing process is performed, the electrolyte 74 shown in FIG.
Such an electrolyte may be fixedly bonded to the electrode active material in cooperation with the interleaf film 82. As shown in FIG. 8, the interleaf film 82 has an at least partially cured electrode active material 8 in order to promote the adhesion with the electrolyte 74.
It extends above zero. Since the electrolyte 74 penetrates into the interleaf film 82 and the interleaf film 82 is permanently bonded to the electrode active material 80, the electrode active material 8
The 0, the interleaf film 82, and the electrolyte 74 are either "coupled" or cooperatively coupled to each other.

The above description and drawings merely illustrate and illustrate the invention, but the invention is not limited thereto. Various changes and modifications of the present invention are possible without departing from the scope of the invention.

[0034]

According to the present invention, a battery having a uniform electrode surface layer formed by using an interleaf film integrally bonded to an electrode active material layer and having improved electrode quality, strength and flexibility can be obtained. Can be provided, and its industrial value is extremely high.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a battery in the prior art.

FIG. 2 is a schematic view of a method for manufacturing a battery electrode in the prior art.

FIG. 3 is a cross-sectional view of an electrode active material layer applied on a current collecting substrate in the prior art.

FIG. 4 is a schematic diagram of a battery of the present invention.

FIG. 5 is a schematic view of a method for manufacturing a battery electrode of the present invention.

FIG. 6 is a schematic view of an interleaf film of the present invention impregnated with a polymerization initiator.

FIG. 7 is a sectional view of an electrode according to the present invention.

FIG. 8 is a cross-sectional view of the electrode of the present invention bonded to an electrolyte.

[Explanation of symbols]

 10: Conventional battery 12: First electrode 14: Electrolyte 16: Second electrode 18: Current collector substrate 20: Electrode active material 22: Current collector substrate 24: Electrode active material 30: Electrode paste pump 32: Mixer 34: Coating head 36: Surface of current collecting substrate 40: Initiator holding container 42: Initiator wick 44: Interleaf 46: Curing furnace 48: Roller 50: Take-up reel 51: Bottom surface of interleaf 52: Electrode receiving roller 60: Irregular surface 70 : Battery of the present invention 72: First electrode 74: Electrolyte 76: Second electrode 78: Current collector substrate 80: Electrode active material 82: Interleaf film 82 ': Upper surface of interleaf film 84: Current collector substrate 86: Electrode active Material 100: Electrode active material pump 102: In mixer 104: Coating head 106: Surface of current collecting substrate 109: Interleaf roller 110: collector roller 111: second interleaf layer 111 ': Roller 112: curing oven 130: electrode take-off reel 132: Roller 136: take-up roller 160: polymerization initiator

Claims (37)

[Claims] 1. A battery electrode comprising a current collector substrate, an electrode active material layer, and an interleaf film integrally bonded to the active material layer. 2. The electrode according to claim 1, wherein said integral interleaf membrane comprises non-woven polypropylene. 3. The electrode according to claim 1, wherein the integrated interleaf film has a means for promoting polymerization of the active material layer. 4. The electrode according to claim 3, wherein said polymerization promoting means is a polymerization initiator capable of bonding to said integral interleaf film. 5. The electrode according to claim 4, wherein said integral interleaf film is impregnated with said polymerization initiator. 6. The electrode according to claim 1, further comprising means for fixing a polymerizable electrolyte to the active material layer. 7. The electrode according to claim 6, wherein the means for fixing the polymerizable electrolyte is the integrated interleaf film having a portion extending above the active material layer. 8. The electrode according to claim 1, further comprising means for facilitating the transfer of ions through said integral interleaf membrane. 9. The electrode according to claim 8, wherein the ion movement promoting means is the integral interleaf film having permeability to predetermined ions. 10. The electrode according to claim 1, further comprising means for increasing the tensile strength and flexibility of the electrode. 11. A battery electrode comprising a current collecting substrate, an electrode active material layer, and an interleaf film containing a polymerization initiator and bonded to the electrode active material layer. 12. The electrode according to claim 11, wherein said interleaf film is made of non-woven polypropylene. 13. The electrode according to claim 11, wherein the integral interleaf film is impregnated with the polymerization initiator. 14. The electrode according to claim 11, further comprising means for fixing a polymerizable electrolyte to the active material layer. 15. The electrode according to claim 14, wherein the means for fixing the polymerizable electrolyte is the integrated interleaf film having a portion extending above the active material layer. 16. The apparatus according to claim 1, further comprising means for facilitating the transfer of ions through said integral interleaf membrane.
2. The electrode according to 1. 17. The electrode according to claim 16, wherein the ion movement promoting means is the integrated interleaf film having permeability to predetermined ions. 18. The electrode according to claim 11, comprising means for increasing the tensile strength and flexibility of said electrode. 19. A battery comprising an electrolyte, a first electrode, and a second electrode, wherein at least one of the first electrode and the second electrode is provided.
One is composed of a current collecting substrate, an electrode active material layer, and an interleaf film integrally bonded to the active material layer, and the interleaf film continuously extends from at least a portion of the active material layer and enters at least a portion of the electrolyte. A battery characterized in that: 20. The battery according to claim 19, wherein said interleaf film comprises non-woven polypropylene. 21. The battery according to claim 19, wherein said integral interleaf film has means for promoting polymerization of the active material layer. 22. The polymerization promoting means is a polymerization initiator capable of bonding to the integral interleaf film.
The battery according to 1. 23. The battery according to claim 22, wherein the integral interleaf film is impregnated with the polymerization initiator. 24. The battery according to claim 19, further comprising means for fixing a polymerizable electrolyte to the active material layer. 25. The apparatus according to claim 1, further comprising means for facilitating the movement of ions through said integral interleaf membrane.
10. The battery according to 9. 26. The battery according to claim 25, wherein the ion transfer promoting means is the integrated interleaf membrane having permeability to predetermined ions. 27. The battery according to claim 19, further comprising means for increasing tensile strength and flexibility of the electrode. 28. A step of attaching a polymerizable active material layer to the surface of a current collecting substrate; a step of integrally bonding an interleaf film to at least a portion of the polymerizable active material layer; Bonding the active material layer to the material layer; and curing the active material layer at least partially. 29. The manufacturing method according to claim 28, wherein the step of integrally bonding the interleaf film includes a step of positioning a part of the interleaf film above a surface of the electrode active material layer. 30. The step of binding the polymerization initiator,
29. The method according to claim 28, further comprising a step of bonding a polymerization initiator to the interleaf film before the step of integrally bonding the interleaf film to at least a part of the electrode active material. 31. The step of binding the polymerization initiator,
The method according to claim 30, further comprising a step of impregnating the interleaf film with the polymerization initiator. 32. The step of at least partially curing the electrode active material comprises curing the electrode active material and the polymerization initiator by exposing the same to at least one of ultraviolet rays, infrared rays, heat energy, and an electron beam. The method according to claim 28, comprising a step. 33. a step of applying a polymerizable active material layer to the surface of the current collecting substrate; a step of integrally bonding an interleaf film to at least a portion of the polymerizable electrode active material layer; Bonding to an active material layer; at least partially curing the active material layer; bonding an electrolyte to the at least partially cured electrode active material; bonding a second electrode adjacent to the electrolyte. And a method for manufacturing a battery. 34. The manufacturing method according to claim 33, wherein the step of integrally bonding the interleaf film includes a step of positioning a part of the interleaf film above the polymerizable electrode active material layer. 35. The step of binding the polymerization initiator,
34. The method according to claim 33, further comprising a step of bonding a polymerization initiator to the interleaf film before the step of integrally bonding the interleaf film to at least a part of the polymerizable electrode active material. 36. The step of binding the polymerization initiator,
The method according to claim 35, further comprising a step of impregnating the interleaf film with the polymerization initiator. 37. The step of at least partially curing the electrode active material comprises curing the electrode active material and the polymerization initiator by exposing the same to at least one of ultraviolet light, infrared light, heat energy, and an electron beam. The production method according to claim 33, comprising a step.