KR20090082223A - Method for manufacturing collector for nonaqueous secondary battery, method for manufacturing electrode for nonaqueous secondary battery, and nonaqueous secondary battery - Google Patents

Abstract

Intended is to improve the mechanical strength and the durability of a collector for a nonaqueous secondary battery, so that an active substance layer may be carried efficiently in a high adhesion on the surface of the collector. This improvement is achieved by using a pair of working means, which have surfaces pressed toward each other to form a pressing nip portion for allowing a sheet-shaped substance to pass therethrough and which have a plurality of recesses formed in at least one surface. A metal foil for the collector is subjected to a compressing treatment by passing it through the pressing nip portion of the working means so that a plurality of projections are formed on at least one surface of the collector metal foil by the partial plastic deformation caused according to the compressing treatment.

Description

METHOD FOR MANUFACTURING COLLECTOR FOR NONAQUEOUS SECONDARY BATTERY, METHOD FOR MANUFACTURING ELECTRODE FOR NONAQUEOUS SECONDARY BATTERY, AND NONAQUEOUS SEC

The present invention relates to a method for producing a current collector for a nonaqueous electrolyte secondary battery, a method for producing an electrode for a nonaqueous electrolyte secondary battery, and a nonaqueous electrolyte secondary battery. In more detail, this invention mainly relates to the improvement of the electrical power collector for nonaqueous electrolyte secondary batteries.

Lithium secondary batteries have high potentials and high capacities, and are relatively easy to be miniaturized and light in weight. In recent years, their use as a power source for portable electronic devices has increased significantly. A typical lithium secondary battery realizes high potential and high capacity by using a carbonaceous material capable of occluding and releasing lithium as a negative electrode active material and a composite oxide of lithium and a transition metal such as LiCoO ₂ as a positive electrode active material. Doing. However, as the portable electronic devices become more versatile and the power consumption increases, the lithium secondary battery used as a power source is also required to improve the deterioration of characteristics due to the charge / discharge cycle.

The electrode which is a power generation element of a lithium secondary battery contains an electrical power collector and an active material layer. The active material layer is generally formed by applying a mixture slurry to one or both surfaces of a current collector, drying, and then performing press molding. The mixture slurry is prepared by mixing and dispersing a positive electrode active material or a negative electrode active material, a binder, and a conductive material in a dispersion medium as necessary.

Here, as one of the factors of the characteristic deterioration by a charge / discharge cycle, the fall of the binding force of the active material layer formed on the surface of an electrical power collector, and an electrical power collector is mentioned. In a lithium secondary battery, due to the expansion and contraction of the electrode in accordance with the charge / discharge cycle, the binding force of both at the interface between the current collector and the active material layer is weakened, resulting in dropping of the active material layer from the current collector and deterioration of characteristics.

In order to raise the binding force of an electrical power collector and an active material layer, it is effective to increase the contact area of both at the interface of an electrical power collector and an active material layer. For this purpose, a method of roughening the surface of the current collector, a method of forming irregularities on the surface of the current collector, and the like have been proposed.

As a roughening method of the surface of an electrical power collector, the method of etching the surface of an electrical power collector by electrolysis, the method of depositing the same metal as the thing contained in an electrical power collector by electrodeposition on the electrical power collector surface, etc. are mentioned, for example.

As a method of forming the unevenness on the surface of the current collector, for example, a method of forming fine unevenness on the surface by colliding fine particles at high speed on the surface of the rolled copper foil which is the current collector (see Patent Document 1, for example). Is proposed. In Patent Literature 1, a current collector having local irregularities can be formed locally, but since velocity distribution occurs in the fine particles to be sprayed from the nozzle, irregularities are uniformly formed in the width direction and the long direction of the current collector. Is difficult.

Moreover, the method (for example, refer patent document 2) of irradiating a laser beam to metal foil and forming the unevenness | corrugation whose surface roughness is 0.5-10 micrometers with a 10-point average roughness is proposed. In patent document 2, a recess is formed by irradiating a laser beam, locally heating a metal foil, and evaporating a metal. And it is possible to form an unevenness | corrugation in the whole surface of metal foil by irradiating a laser beam continuously. However, since the laser beam is scanned in a linear shape, the metal foil is locally heated to a high temperature above the melting point of the metal foil, whereby wavy crinkling, wrinkling and warping of the metal foil occur. It is difficult to prevent that. In addition, when laser processing the metal foil of thickness 20 micrometers or less like the electrical power collector of a lithium secondary battery, the defect which a hole is made to a metal foil may be caused by the output nonuniformity of a laser.

Moreover, the roller which formed the unevenness | corrugation on the surface, and the roller in which the hard rubber layer was formed on the surface were made to contact so that each axis line may become parallel, the current collector may be passed through this contact part, and the method of forming an unevenness | corrugation in an electrical power collector is mentioned. (For example, refer patent document 3). In patent document 3, in order to improve the output density of a lithium secondary battery, without forming the thickness of an active material layer, unevenness | corrugation is formed in an electrical power collector. In patent document 3, since the roller in which the hard rubber layer was formed on the surface is used, even if an electrical power collector passes through a contact part of a roller and a roller, plastic deformation hardly arises.

Moreover, in order to improve the binding force and electrical conductivity of an electrical power collector and an active material layer, the electrical power collector which has a specific unevenness | corrugation is proposed (for example, refer patent document 4). FIG.20 (a)-(e) is a perspective view which shows typically the structure of the electrical power collector of patent document 4. As shown in FIG. As for the electrical power collector of patent document 4, when the local part in one surface of the metal foil is concave, the part corresponding to the said local part in the other surface protrudes outwardly from the other surface regularly Formed. This current collector did not have sufficient mechanical strength. In addition, when the active material layer is formed on such a current collector, the thickness of the active material layer tends to be nonuniform, and consequently adversely affects battery performance.

In addition, in patent documents 1-4, when recessed part is formed in one surface of metal foil, the part corresponding to the said recessed part in the other surface cannot necessarily become a convex part, When forming an unevenness | corrugation, It is difficult to prevent the occurrence of wavy wrinkles, wrinkles, warpage, and the like.

In addition, a current collector made of punch metal having a porosity of 20% or less having an unevenness formed by embossing, and an active material layer filled in a recess of the current collector, and the convex portions of the current collector are exposed or Or the electrode by which the active material adhered to the convex part is proposed (for example, refer patent document 5). FIG. 21: is a longitudinal cross-sectional view which shows typically the structure of the electrodes 101-103 of patent document 5. As shown in FIG. The electrode 101 shown in FIG. 21A includes a current collector 110 having irregularities formed thereon, and an active material layer 111 filled in the recess 110b of the current collector 110. The active material layer 111 also adheres to the surface of the convex portion 30a of the 110. In the electrodes 102 and 103 shown in Figs. 21B and 21C, the convex portions 120a and 130a of the current collectors 120 and 130 are exposed, respectively. In Patent Literature 5, embossing is performed on punched metal having a porosity of 20% or less to form irregularities, so that the obtained current collector did not have sufficient mechanical strength. For this reason, the defect that an electrode breaks may arise.

Moreover, the electrode which contains a collector and an active material layer, and whose value of (surface roughness Ra of an active material layer)-(surface roughness Ra of an electrical power collector) is 0.1 micrometer or more is proposed (for example, refer patent document 6). Usually, when the thin film of an active material is formed on the surface of an electrical power collector by the vacuum vapor deposition method etc., the thin film which has almost the same surface roughness as the surface of an electrical power collector is obtained. On the other hand, in patent document 6, the surface roughness of a thin film is adjusted to the said specific value by performing processes, such as sandblasting and surface grinding | polishing, to the thin film formed by the normal method. Accordingly, it is intended to alleviate the expansion stress of the active material. Although the technique of patent document 6 is effective to some extent from the point which prevents a crack of an active material, the thin film of an active material is formed in the whole surface of an electrical power collector surface, and peeling from an electrical power collector of a thin film, deformation of an electrode, etc. are easy to occur. Lose. As a result, the charge / discharge cycle characteristics deteriorate.

Patent Document 1: Japanese Unexamined Patent Publication No. 2002-79466

Patent Document 2: Japanese Unexamined Patent Publication No. 2003-258182

Patent Document 3: Japanese Patent Application Laid-Open No. 8-195202

Patent Document 4: Japanese Unexamined Patent Publication No. 2002-270186

Patent Document 5: Japanese Unexamined Patent Publication No. 2005-32642

Patent Document 6: Japanese Unexamined Patent Publication No. 2002-279972

[Initiation of invention]

[Problem to Solve Invention]

An object of the present invention is to provide a method for producing a current collector for a nonaqueous electrolyte secondary battery, in which a plurality of convex portions capable of efficiently carrying an active material layer on at least one surface thereof are formed without undergoing compression processing and have high mechanical strength. .

Another object of the present invention is to provide a method for producing an electrode for nonaqueous electrolyte secondary batteries, including a current collector obtained by the method for producing a current collector for nonaqueous electrolyte secondary batteries and an active material layer.

Still another object of the present invention is to provide a nonaqueous electrolyte secondary battery including an electrode produced by the method for producing an electrode for nonaqueous electrolyte secondary batteries of the present invention.

[Means for solving the problem]

The present invention uses a pair of processing means which are provided to form a press-contacting nip portion through which the surfaces are press-contacted with each other and through which sheet-like objects can pass, and in which a plurality of recesses are formed on at least one surface, thereby processing the metal foil for current collector. The present invention relates to a method for producing a current collector for nonaqueous electrolyte secondary batteries, which is subjected to compression processing by passing through a pressure contact nip portion to form a plurality of convex portions on at least one surface of the metal foil for current collectors.

It is preferable that the surface roughness of the front surface of the convex portion is substantially the same as the surface roughness of the metal foil for current collector before compression processing.

It is preferable that the cross section of the direction perpendicular | vertical to the processing means surface of a recessed part has a taper shape in which the width | variety of the direction parallel to the processing means surface of the said cross section becomes small gradually toward the bottom of a recessed part from a processing means surface.

It is preferable to perform compression processing so that the volume of a convex part may be below the volume of the internal space of a recessed part.

It is preferable to perform compression processing so that the volume of the convex portion becomes 85% or less of the volume of the inner space of the concave portion.

In the processing means in which a plurality of recesses are formed on the surface, it is preferable that the boundary between the recess and the surface of the processing means is a curved surface.

It is preferable that the curved surface of the boundary between the recessed portion and the surface of the processing means is formed by forming the recessed portion by laser processing and removing the ridges of the boundary between the recessed portion and the surface of the processing means generated by laser processing. Do.

It is preferable to remove ridge | swelling by grinding | polishing with the diamond particle of the average particle diameter of 30 micrometers or more and less than 53 micrometers.

It is preferable that a plurality of grooves having a width of 1 m or less and a depth of 1 m or less are formed on the boundary between the recess and the surface of the processing means.

It is preferable to form a groove by polishing with diamond particles having an average particle diameter of 5 µm or less.

It is preferable that a pair of processing means is a pair of roller, and the recessed part is formed in the surface of at least one roller.

It is preferable that the surface coating layer containing cemented carbide, alloy steel or chromium oxide is formed in the surface of the roller in which the recessed part is formed, and the surface which faces the inner space of a recessed part. It is preferable that the protective layer containing an amorphous carbon material is formed in the surface of a surface coating layer.

The surface coating layer and the protective layer are at least one selected from the group consisting of a physical vapor deposition method using sputtering, a physical vapor deposition method using ion implantation, a chemical vapor deposition method using thermal deposition, and a chemical vapor deposition method using plasma deposition. It is preferable to form by the vapor phase growth method.

It is preferable that at least one roller is a roller which provided the ceramic layer on the surface, and the recessed part is formed in the surface of the ceramic layer.

It is preferable to apply a lubricant to the surface of the metal foil for rollers or an electrical power collector, and to dry.

It is preferred that the lubricant contains a fatty acid.

Moreover, this invention includes the base material part which consists of metal foil for electrical power collectors, and the some convex part formed so that it may extend outward from the at least one surface of a base material part, and the boundary of a base material part and a convex part is a non-aqueous electrolyte secondary The present invention relates to a battery current collector.

In addition, the present invention, the positive electrode active material or the negative electrode active material on the surface of the current collector for a non-aqueous electrolyte secondary battery or the non-aqueous electrolyte secondary battery current collector produced by any one of the method for manufacturing a current collector for a non-aqueous electrolyte secondary battery A method for producing an electrode for a nonaqueous electrolyte secondary battery.

It is preferable to carry a positive electrode active material or a negative electrode active material on the surface of the convex portion of the current collector for nonaqueous electrolyte secondary batteries.

Moreover, this invention is a nonaqueous electrolyte secondary battery containing a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte,

At least one of a positive electrode and a negative electrode relates to the nonaqueous electrolyte secondary battery which is an electrode manufactured by the manufacturing method of said electrode for nonaqueous electrolyte secondary batteries.

[Effects of the Invention]

According to the manufacturing method of the current collector for non-aqueous secondary batteries of this invention, since the convex part is formed without receiving a compression process, mechanical strength improves and a durable current collector can be obtained.

Moreover, the convex part is formed by plastic deformation without receiving a compression process. In addition, since the distal end surface of the convex portion is formed almost without the influence of compression processing and the resulting plastic deformation, it has almost the same surface roughness as the metal foil for current collector before compression processing. The electrical power collector which has such a convex part improves mechanical strength and durability further, and, when carrying an active material layer, adhesiveness with an active material layer is very strong.

Moreover, in the electrical power collector containing a base material part and the some convex part formed so that it may extend outwardly from the at least one surface of a base material part, the mechanical part of a current collector may be made into the boundary part of a base part surface and a convex part by making it curved surface. Strength and durability are further improved. Further, the convex portion can be formed at a lower pressure during compression processing, and the releasability from the processing means of the current collector after compression processing can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows typically the manufacturing method of the electrical power collector which is one of embodiment of this invention.

FIG. 2: is a longitudinal cross-sectional view which typically demonstrates plastic deformation of the metal foil for electrical power collectors by compression processing. FIG.

3 is a side view schematically showing the configuration of a current collector manufacturing apparatus.

FIG. 4 is an enlarged perspective view showing the configuration of main parts of the current collector manufacturing apparatus shown in FIG. 3. FIG.

FIG. 5 is a diagram illustrating a configuration of a roller used for compression processing. FIG. Fig. 5A is a perspective view showing the appearance of the roller. FIG. 5 (b) is an enlarged perspective view showing the surface area of the roller shown in FIG. 5 (a).

FIG. 6: is a longitudinal cross-sectional view which shows typically the manufacturing method of the electrical power collector of another form which is one of embodiment of this invention. FIG.

7 is a longitudinal cross-sectional view schematically showing the configuration of a current collector obtained by the method for manufacturing a current collector for nonaqueous electrolyte secondary batteries of the present invention.

FIG. 8 is a longitudinal sectional view schematically showing the method of manufacturing the current collector shown in FIG. 7.

Fig. 9 is a diagram illustrating a configuration of rollers of another form used for compression processing. Fig. 8A is a perspective view showing the appearance of the roller. FIG. 8B is an enlarged perspective view of the surface area of the roller shown in FIG. 8A. FIG. 8C is an enlarged perspective view of the recess formed in the roller circumferential surface shown in FIG. 8B.

Fig. 10 is a longitudinal sectional view schematically showing the configuration of a current collector of another embodiment obtained by the method for manufacturing a current collector for nonaqueous electrolyte secondary batteries of the present invention.

FIG. 11 is a longitudinal sectional view schematically showing the method of manufacturing the current collector shown in FIG. 10. FIG.

12 is a partially exploded perspective view schematically showing the configuration of a wound nonaqueous electrolyte secondary battery, which is one of the embodiments of the present invention.

Fig. 13 is a longitudinal sectional view schematically showing the configuration of a stacked nonaqueous electrolyte secondary battery as one of the embodiments of the present invention.

FIG. 14 is a diagram schematically showing the configuration of a current collector obtained in Example 5. FIG. Fig. 14A is a perspective view. (B) is a longitudinal cross-sectional view.

FIG. 15 is a diagram schematically showing a configuration of a current collector obtained in Example 6. FIG. Fig. 15A is a perspective view. Fig. 15B is a longitudinal sectional view.

FIG. 16 is a diagram schematically showing a configuration of a current collector obtained in Example 24. FIG. Fig. 16A is a perspective view. (B) is a longitudinal cross-sectional view.

FIG. 17 is a diagram schematically showing a configuration of a current collector obtained in Example 25. FIG. Fig. 17A is a perspective view. Fig. 17B is a longitudinal sectional view.

18 is an electron micrograph of a cross section of the current collector obtained in Example 1. FIG.

19 is an electron micrograph of a cross section of the current collector obtained in Comparative Example 1. FIG.

20 is a perspective view schematically showing the configuration of a current collector of the prior art.

Fig. 21 is a longitudinal sectional view schematically showing the configuration of an electrode of the prior art.

According to the manufacturing method of the current collector for non-aqueous secondary batteries of this invention, in the process of forming a convex part in the surface of the metal foil for electrical power collectors, a process of supporting an electrode active material in the convex part of an electrical power collector, etc. Local deformation, deflection, bending, tearing, etc. can be prevented from occurring. In addition, the fall of the electrode active material from an electrical power collector can be suppressed also in the process of preparing an electrode by supporting an electrode active material in the convex part of an electrical power collector, and the process of slitting an electrode to a predetermined width | variety. Therefore, a highly reliable nonaqueous electrolyte secondary battery is finally obtained.

Best Mode for Carrying Out the Invention

[Manufacturing method of current collector for nonaqueous electrolyte secondary battery]

The method for producing a current collector for a nonaqueous electrolyte secondary battery of the present invention (hereinafter simply referred to as a method for manufacturing a current collector) is characterized in that the metal foil for current collector is passed through a pressure welding nip portion of a pair of processing means to perform compression processing. It is done. More specifically, by adopting the above configuration, by generating partial plastic deformation on the surface of the metal foil for current collectors, the tip surface forms a convex portion that is hardly affected by compression processing and plastic deformation. .

Here, a pair of processing means is a pair of processing means provided so that the surface may contact each other and form the press contact nip part which a sheet-like thing can pass through, and the some recessed part was formed in at least one surface. As a pair of processing means, a pair of roller is preferable. A plurality of recesses are formed in at least one surface of a pair of rollers. In the compression processing of the present invention, for example, a metal foil for current collector is passed through a press-contacting nip portion of a pair of rollers, and the metal foil for current collector is mechanically pressed to partially plastically deform the metal foil for current collector. Is made by When a pair of rollers is subjected to compression processing to produce a current collector having convex portions on its surface, the convex portions can be almost certainly prevented from peeling off and falling off from the current collector. Moreover, the electrical power collector which has a convex part in the surface can be manufactured efficiently at low cost.

According to the manufacturing method of the electrical power collector of this invention, the electrical power collector for nonaqueous electrolyte secondary batteries (henceforth simply a "current collector") by which the several convex part was formed in one surface of the thickness direction is obtained.

1: is a longitudinal cross-sectional view which shows typically the compression process of the metal foil 10 for electrical power collectors which is one of embodiment of this invention. FIG. 2: is a longitudinal cross-sectional view which typically demonstrates plastic deformation of the metal foil 10 for electrical power collectors by compression processing. 3 is a side view schematically showing the configuration of the current collector manufacturing apparatus 35. FIG. 4 is an enlarged perspective view showing the configuration of the main portion (processing means 37) of the current collector manufacturing apparatus 35 shown in FIG. FIG. 5 is a diagram illustrating a configuration of the roller 4 used for compression processing. Fig. 5A is a perspective view showing the appearance of the roller 4. FIG. 5B is an enlarged perspective view of the surface area 4x of the roller 4 shown in FIG. 5A.

The manufacturing method of the electrical power collector of this invention is performed using the electrical power collector manufacturing apparatus 35 shown in FIG. 3, for example. The current collector manufacturing apparatus 35 includes a metal foil supply means 36, a processing means 37, and a current collector winding-up means 38.

The metal foil supply means 36 is a metal foil supply roller specifically ,. The metal foil supply roller is axially supported by the support means which is not shown so that rotation is possible about an axis line. The metal foil 10 for electrical power collectors is wound by the circumferential surface of the metal foil supply roller. The metal foil 10 for current collectors is supplied to the pressure welding nip part 6 of the processing means 37.

The metal foil 10 for electrical power collectors is metal foil which consists of metal materials which do not produce an electrochemical reaction with lithium. In the case of producing the negative electrode current collector 1 from the current collector metal foil 10, the current collector metal foil 10 is, for example, copper, nickel, iron, an alloy containing at least one of these, or the like. Metal foil etc. which consist of these can be used. Among these, metal foil which consists of copper or a copper alloy is preferable. Examples of the copper alloy include zinc-containing copper, tin-containing copper, silver-containing copper, zirconium-containing copper, chromium copper, tellurium copper, titanium copper, beryllium copper, iron-containing copper, phosphorus-containing copper, aluminum copper and the like. And these 2 or more types of composite alloys are mentioned. As metal foil of copper and a copper alloy, electrolytic copper foil, electrolytic copper alloy foil, rolled copper foil, copper alloy foil, rolled copper alloy foil, the foil which carried out the roughening process to these, etc. are mentioned, for example. Although the thickness of the metal foil for negative electrode collectors is not specifically limited, Preferably it is about 5-100 micrometers.

When producing the positive electrode current collector 1 from the current collector metal foil 10, as the current collector metal foil 10, for example, a metal foil made of aluminum, an aluminum alloy, stainless steel, titanium, or the like can be used. Can be. Although the thickness in particular of the metal foil for positive electrode electrical power collectors is not restrict | limited, Preferably it is about 5-100 micrometers. Of course, you may perform a roughening process also to these metal foils.

The processing means 37 includes the rollers 4 and 5 as shown in FIG. 3 and FIG. 4. The rollers 4 and 5 are press-contacted so that mutual axis lines may become parallel, and the press-contact nip part 6 is formed. In the press-contacting nip part 6, sheet-like objects, such as the metal foil 10 for electrical power collectors, can pass. In addition, the rollers 4 and 5 are axially supported so as to be rotatable by supporting means, not shown, respectively, and are provided so as to be able to rotate around the axis by the driving means not shown. The rollers 4 and 5 may be both driving rollers, or one may be a driving roller, and the other may be a driven roller which rotates in accordance with the rotation of the driving roller. By the rotation drive of the rollers 4 and 5, the metal foil 10 for electrical power collectors is guide | induced from the inlet_port | entrance of the pressure welding nip part 6, and compression processing is given to the metal foil 10 for electrical power collectors, and FIG. The current collector 1 shown in (c) is obtained.

The current collector 1 includes a base portion 2 and a plurality of convex portions 3. The base material part 2 is a plate-shaped part by which the metal foil 10 for electrical power collectors was compressed in the thickness direction. The convex part 3 is a protrusion part formed so that it may extend to the outer side of the base material part 2 from the one surface 2a of the base material part 2. The convex part 3 is formed without receiving a compression process.

The roller 4 is a roller in which the some recessed part 4a was formed in the circumferential surface. The roller 4 is, for example, recessed in a recess forming roller made of one or two or more metal materials selected from the group consisting of various metals and alloys, preferably made of stainless steel, iron hardened steel, or the like. It can manufacture by forming the part 4a.

On the circumferential surface of the concave forming roller, a coating layer containing cemented carbide or alloy steel ball may be formed. By forming such a coating layer, since the surface hardness of the roller 4 finally obtained becomes further higher, when the compression processing of the metal foil 10 for electrical power collectors is carried out, it can suppress that the shape of the convex part 3 formed is non-uniform. Can be.

Moreover, you may form the coating layer containing a cemented carbide or a chromium oxide in the peripheral surface of the recess formation roller. This coating layer has the effect of alleviating resistance such as frictional force and stress under pressure. Therefore, when the roller 4 manufactured from the recessed formation roller which formed such a coating layer is used, the resistance which arises between the roller 4 and the metal foil 10 for electrical power collectors at the time of a compression process will be alleviated. As a result, after compression processing, the releasability from the roller 4 of the collector 1 is improved, the process management becomes easy, the defective article rate falls, and it is industrially advantageous. On the other hand, since such a coating layer is firmly bonded with the roller for forming a recess, even when it is used repeatedly, there is very little case where the coating layer peels off, and it is industrially advantageous in this respect as well.

In addition, a protective layer containing an amorphous carbon material may be formed on the surface of the cemented carbide or the coating layer containing chromium oxide. Thereby, the surface hardness of the roller 4 finally obtained improves further, the relaxation of the resistance which arises between the roller 4 and the metal foil 10 for electrical power collectors at the time of a compression process, and after a compression process The improvement of the releasability from the roller 4 of the collector 1 becomes further remarkable.

The various coating layers and protective layers described above include, for example, physical vapor deposition using sputtering, physical vapor deposition using ion implantation, chemical vapor deposition using thermal deposition, chemical vapor deposition using plasma deposition, and the like. It is preferable to form by the vapor phase growth method. Thereby, the release property from the roller 4 of the electrical power collector 1 after compression processing can be aimed at.

On the peripheral surface of the recess forming roller, a coating layer made of ceramics such as tungsten carbide (WC) and titanium nitride (TiN) may be formed. Thereby, the surface hardness of the roller 4 finally obtained can be raised, and it can suppress that the shape of the convex part 3 formed by plastic deformation without receiving a compression process can be suppressed.

In the present invention, the recessed portions 4a may be formed in the various coating layers or protective layers described above.

The recessed part 4a can be formed by etching, sand blasting, electric discharge machining, laser processing, etc., for example. Among these, laser processing is preferable. According to the laser processing, the arrangement pattern of the fine concave portion 4a and the concave portion 4a having the order of several micrometers order can be formed almost accurately. As a laser used for laser processing, a carbon dioxide gas laser, a YAG laser, an excimer laser, etc. are mentioned, for example. Among these, a YAG laser is preferable. On the other hand, when laser processing is performed, the edge of the opening part of the recessed part 4a in the peripheral surface of the roller 4 will rise. The collector 1 can be obtained even if it is used as it is without removing the ridge of the roller 4. Moreover, you may use after removing the ridge | bulb of the roller 4 by grinding | polishing processing etc.

In addition, the arrangement pattern of the recessed part 4a in the peripheral surface of the roller 4 is as follows in this embodiment. As shown in FIG.5 (b), the column in which the some recessed part 4a was arranged by pitch Pa in the longitudinal direction of the roller 4 is set to one row unit 7. As shown in FIG. The plurality of row units 7 are arranged at a pitch Pb in the circumferential direction of the roller 4. The pitch Pa and the pitch Pb can be arbitrarily set. On the other hand, in the circumferential direction of the roller 4, the one row unit 7 and the adjacent row unit 7 are arranged so that the recessed part 4a may shift in the longitudinal direction of the roller 4. In this embodiment, although the shift | deviation of the longitudinal direction of the recessed part 4a is 0.5 Pa, it is not limited to this, Arbitrary setting is possible. In addition, in this embodiment, although the shape of the opening part of the recessed part 4a in the circumferential surface of the roller 4 is nearly circular, it is not limited to this, For example, it is almost elliptical, almost rectangular, nearly rhombic, and nearly It may be a square, an almost hexagon, or an almost octagon.

Further, the cross section in the direction perpendicular to the roller 4 circumferential surface of the concave portion 4a has a concave portion 4a having a width in a direction parallel to the roller 4 circumferential surface of the cross section from the roller 4 circumferential surface. It is desirable to have a tapered shape that gradually decreases toward the bottom of the. Thereby, the releasability from the roller 4 of the electrical power collector 1 after completion of a compression process improves.

On the circumferential surface of the roller 4 and the surface facing the inner space of the recessed portion 4a, a coating layer containing cemented carbide, a coating layer containing alloy pores, a coating layer containing chromium oxide, a protective layer containing an amorphous carbon material, and the like 1 or 2 or more may be formed. Thereby, the same effect as what forms these coating layer and protective layer in the recess formation roller is acquired. In addition, by forming these coating layers and protective layers by the physical vapor deposition method, the chemical vapor deposition method, etc. as mentioned above, the same effect as the above is acquired. According to these vapor phase growth methods, a coating layer and a protective layer can be formed uniformly also on the surface which faces the internal space of the recessed part 4a. In addition, cobalt is contained in materials such as cemented carbide as a binder, and when the current collector metal foil 10 contains copper, the affinity between cobalt and copper is high. It is effective for preventing adhesion to the inner surface of the recess 4a.

Moreover, you may form the coating layer which consists of ceramics, such as tungsten carbide (WC) and titanium nitride (TiN), on the peripheral surface of the roller 4 and the surface which faces the inner space of the recessed part 4a. Thereby, the surface hardness of the roller 4 improves, and the nonuniformity of the shape of the convex part 3 by plastic deformation by compression processing becomes very small.

As the roller 5, a roller having a smooth or flat circumferential surface, preferably a metal roller having a smooth or flat circumferential surface can be used.

The pressure contact pressure of the rollers 4 and 5 is not particularly limited, but is preferably about 8 kN to 15 kN per cm of the metal foil 10 for current collectors.

In addition, during the compression processing of the metal foil 10 for current collectors by the processing means 37, a lubricant may be applied to at least one of the roller 4 and the metal foil 10 for current collectors. The lubricant is applied to the peripheral surface of the roller 4 or the surface of the metal foil 10 for current collectors and dried. Thereby, the resistive force which arises between the roller 4 and the collector metal foil 10 at the time of a compression process can be reduced, and the mold release property from the roller 4 of the collector 1 further improves. The lubricant more preferably contains fatty acids. Among the fatty acids, saturated fatty acids are preferred, and myristic acid is particularly preferred. Fatty acids are preferably used in the form of solutions. As a solvent which dissolves a fatty acid, it is preferable to dissolve a fatty acid and to volatilize easily by drying, For example, low boiling point solvents, such as methanol and ethanol, etc. can be used. By applying and drying the fatty acid, the resistance generated during compression processing, in particular, the frictional force is further reduced, elongation in the longitudinal direction of the current collector metal foil 10 is suppressed, and the original metal foil 10 for crystals is determined. The convex part 3 which maintains a structure substantially is formed stably. As a result, it is remarkably suppressed that the convex part 3 peels off and falls off from the base material part 2.

The partial plastic deformation of the metal foil 10 for electrical power collectors by the processing means 37 is demonstrated based on FIG. 1 and FIG. FIG.1 (a) is a longitudinal cross-sectional view which shows the state immediately after the metal foil 10 for electrical power collectors was supplied to the pressure welding nip part 6 of the processing means 37. As shown in FIG. FIG.1 (b) is a longitudinal cross-sectional view which shows the state in which the plastic deformation progresses in one surface of the metal foil 10 for electrical power collectors in the pressure welding nip part 6. As shown in FIG. FIG.1 (c) is a longitudinal cross-sectional view of the electrical power collector 1 after passing through the pressure contact nip part 6. As shown in FIG.

2 shows the progress of the plastic deformation shown in FIG. 1 (b) in three stages.

In the step shown in Fig. 1 (a), the metal foil 10 for the current collector is pressed against you have a film thickness in the inlet t ₀ of peubu 6. The metal foil 10 for current collectors is pressed in contact with the surfaces of the rollers 4 and 5.

In the process shown in FIG.1 (b), the metal foil 10 for electrical power collectors is pressed in the thickness direction. The surface of the metal foil 10 for electrical power collectors exists in the circumference | surroundings of the non-contact surface 4b and the non-contact surface 4b which oppose the recessed part 4a of the roller 4, and also the peripheral surface of the roller 4 It is divided into contact surfaces 4c in contact with the flat portions of. The contact surface 4c is compression-processed in the thickness direction, and the base material part 2 is formed. The thickness of the substrate section (2) is a t _1. t ₁ is less than t ₀ . On the other hand, since the non-contact surface 4b is not pressurized, plastic deformation occurs as the contact surface 4c is compressed. As a result, the non-contact surface 4b swells toward the bottom of the recessed portion 4a in the space of the recessed portion 4a, so that the convex portion 3 is formed. That is, the convex part 3 is formed by the plastic deformation accompanying compression processing, without receiving the compression processing by pressurization. In addition, the non-contact surface 4b becomes the front end surface of the convex part 3. Since the front end surface of the convex part 3 does not perform compression processing at all, it has almost the same surface roughness as the original metal foil 10 surface for electrical power collectors.

Progress of plastic deformation in the process shown in FIG. 1 (b) will be described in more detail based on FIG. 2.

In the process shown to Fig.2 (a), the metal foil 10 for electrical power collectors is supplied to the pressure welding nip part 6. As shown in FIG. At this time, the current collector metal foil 10 has a thickness t ₀ . In the opposing part 4b of the roller 4 of the metal foil 10 for electrical power collectors to the recessed part 4a, the recessed part (1) from the direction of arrow 11a, 11b, ie, inside the metal foil 10 for electrical power collectors ( The stress is added toward 4a). Thus, in the opposing portion 4a, plastic deformation starts to occur.

In the process shown in FIG.2 (b), the plastic deformation of the non-contact surface 4b advances, the non-contact surface 4b raises toward the bottom of the recessed part 4a, and the convex part 3x is formed. The volume of the convex part 3x occupies about 50% of the space volume in the recessed part 4a. Since the front end surface of the convex part 3x does not perform compression processing, it has almost the same surface state as the original metal foil 10 for electrical power collectors. To the convex part 3x, the stress 12a, 12b which pushes up the convex part 3x toward the bottom part of the recessed part 4a is further added. Thereby, plastic deformation further advances along the inner wall surface of the recessed part 4a.

In the process shown in FIG.2 (c), the plastic deformation of the opposing part 4b advances to the limit of the space volume inside the recessed part 4a, and the convex part 3 is formed and the electrical power collector 1 Is obtained.

On the other hand, air exists in the inside of the recessed part 4a. Therefore, when the plastic deformation of the opposing portion 4b proceeds, the air is compressed to lose its place to escape, so that the stress in the direction of the arrows 13a, 13b, 14 with respect to the convex portion 3 is added. do. If this stress becomes large, there exists a possibility that the base material part 2 may deform | transform, and wrinkles, curvature, etc. may arise in the electrical power collector 1. Moreover, there exists a possibility that the shape, size, etc. of the convex part 3 may become nonuniform.

For this reason, the compression processing is preferably performed so that the volume of the convex portion 3 is preferably equal to or less than the space volume inside the recess 4a, and more preferably equal to or less than 85% of the volume of the space inside the recess 4a. good. Thereby, the electrical power collector 1 can be efficiently produced, suppressing generation | occurrence | production of defects, such as wrinkles, curvature, and a break. By further performing compression processing so that the volume of the convex portion 3 is 85% or less of the space volume in the concave portion 4a, the front end surface of the convex portion 3 is the original metal foil 10 for the current collector. The side effect that the convex part 3 can be formed so that it may have almost the same surface roughness as the surface is acquired. As a result, the active material can be prevented from peeling off from the current collector 1 in the step of preparing the electrode by supporting the active material layer on the surface of the convex portion 3, the step of slitting the electrode to a predetermined width, and the like.

Here, it returns to the description based on FIG. In the process shown in FIG.1 (c), the convex part 3 is formed without receiving a compression process. Therefore, in the direction in which the convex part 3 extends, the surface of the front end of the convex part 3 does not produce processing distortion, etc., and the surface state (surface roughness) and the surface of the metal foil 10 for electrical power collectors do not arise. It keeps the precision as it is. The side surface of the convex part 3 also has the surface state near the metal foil 10 for electrical power collectors. On the other hand, since the recessed part 2a which exists between the adjacent convex parts 3 is subjected to compression processing, it has a surface state different from the metal foil 10 for electrical power collectors. The maximum thickness t ₂ of the current collector 1 is the length from the surface of the current collector 1 in which the convex portion 3 is not formed to the tip surface of the convex portion 3 in the thickness direction of the current collector 1. to be. The maximum thickness t ₂ of the current collector ₁ is larger than the thickness t ₀ of the metal foil 10 for current collectors. On the other hand, the relationship between the thickness t ₀ and the maximum thickness t ₂ can be adjusted, for example, by appropriately selecting the pressing force in the pressure welding nip portion 6.

In the current collector 1 obtained by the roller working method, an interface does not exist between the base material portion 2 and the convex portion 3, and has almost the same crystal state, and from the base material portion 2 to the convex portion 3. At least one area | region continuously exists. When the cross section in the thickness direction of the current collector 1 is observed with an electron microscope, a region having almost the same crystal state exists in at least a part of the cross section, and the region is the base portion 2 and the convex portion 3. It is connected on both sides of the road without interruption. As long as observed with an electron microscope, a crystal state indicating the presence of a junction is not recognized in this region. By adopting such a configuration, it is possible to remarkably prevent the convex portion 3 from being peeled off from the substrate portion 2 or peeling from the convex portion 3 of the active material layer.

Here, it returns to the description based on FIG. The current collector winding means 38 is specifically, a current collector winding roller. The current collector winding roller is axially supported to be rotatable about an axis by supporting means (not shown). In addition, the collector winding roller is rotationally driven by driving means (not shown). The current collector winding roller winds up the current collector 1 formed by the processing means 37 on its circumferential surface while rotating.

According to the current collector manufacturing apparatus 35, the metal foil 10 for current collectors is compressed to partially generate plastic deformation, and the current collector 1 including the base material 2 and the plurality of convex portions 3 is provided. Are manufactured.

In addition, by compressing by using the current collector manufacturing apparatus 35 having the above-described configuration, the surface of the metal foil 10 for current collectors can be pressed linearly and with a very small area. Even if it is relatively small, it becomes possible to perform sufficient compression processing. Therefore, the current collector manufacturing apparatus 35 can be downsized. Moreover, by using the electrical power collector manufacturing apparatus 35, it becomes possible to form the convex part 3 continuously on the surface of the strip-shaped metal foil 10 for electrical power collectors, and it is industrially advantageous.

6 is a longitudinal sectional view schematically showing a method for producing a current collector of another embodiment, which is one of embodiments of the present invention. FIG. 6: (a) is a longitudinal cross-sectional view which shows the state immediately after the metal foil 10 for electrical power collectors was supplied to the pressure welding nip part 6. FIG. FIG. 6B is a longitudinal cross-sectional view illustrating a state where plastic deformation of the surface of the current collector metal foil 10 is progressing in the pressure welding nip portion 6. 6C is a longitudinal cross-sectional view of the current collector 1 after passing through the pressure contact nip part 6. The manufacturing method of the collector 15 shown in FIG. 6 is similar to the manufacturing method of the collector 1 shown in FIG. 1, and attaches | subjects the same code | symbol about the corresponding part, and abbreviate | omits description.

The manufacturing method of the electrical power collector 15 shown in FIG. 6 uses a recessed part formed in the surface of both processing means as a pair of processing means, and the electrical power collector 1 shown in FIG. Can be carried out in the same manner as the manufacturing method of.

The manufacturing method of the electrical power collector 15 is performed using the electrical power collector manufacturing apparatus which attached the roller 4 instead of the roller 5 in the electrical power collector manufacturing apparatus 35 shown in FIG. 3, for example. Based on FIG. 6, the manufacturing method of the electrical power collector 15 is demonstrated.

In the step shown in Figure 6 (a), the metal foil 10 for the current collector is pressed against you have a film thickness in the inlet t ₀ of peubu 6. The metal foil 10 for current collectors is pressed in contact with the peripheral surfaces of the two rollers 4. The non-contact surface 4b and the roller 4 which both surfaces of the thickness direction of the metal foil 10 for electrical power collectors oppose the recessed part 4a of the roller 4, and do not contact the circumferential surface of the roller 4, It is divided into the contact surface 4c which contacts a circumferential surface. The contact surface 4c exists around the non-contact surface 4b. On the other hand, the two rollers 4 are arrange | positioned and press-contacted so that the some recessed part 4a shape | molded on the circumferential surface may oppose.

In the process shown in FIG. 6B, the contact surface 4c is compressed to form the base portion 16. The thickness of the base material portion 16 is t ₃ . t ₃ is less than t ₀ . In contrast, since the non-contact surface 4b is not pressurized, plastic deformation occurs as the contact surface 4c is compressed. As a result, the non-contact surface 4b swells toward the bottom of the recessed portion 4a in the space of the recessed portion 4a, and convex portions 17x and 17y are formed. That is, the convex parts 17x and 17y are not subjected to compression by pressure, and are formed by plastic deformation accordingly. The non-contact surface 4b becomes the tip surface of the convex parts 17x and 17y hardly affected by compression processing and plastic deformation, and has almost the same surface roughness as the metal foil 10 for electrical power collectors.

In the step shown in FIG. 6C, the current collector 15 is obtained. The protrusions 17x and 17y are formed without undergoing compression processing. Accordingly, in the direction in which the convex portions 17x and 17y extend, the distal surfaces of the convex portions 17x and 17y have almost no surface distortion and surface roughness and surface precision of the metal foil 10 for current collectors. have. The side surfaces of the convex portions 17x and 17y are not subjected to compression processing, but are affected by plastic deformation, and therefore have surface roughness close to that of the metal foil 10 for current collectors. On the other hand, since the surface of the base material part 16 which exists between the adjacent convex parts 17x and 17y is subjected to compression processing, it has a surface state different from the metal foil 10 for electrical power collectors. The maximum thickness t ₄ of the current collector 1 is the length between the tip surface planes of the convex portions 17x and 17y formed on both surfaces in the thickness direction of the current collector 1. The maximum thickness t ₄ of the current collector 1 is larger than the thickness t ₀ of the original metal foil 10 for current collectors. On the other hand, the relationship between the thickness t ₀ and the maximum thickness t ₄ can be adjusted by appropriately selecting the pressing force in the pressure welding nip part 6, for example.

[Current collector for nonaqueous electrolyte secondary battery]

FIG. 7: is a longitudinal cross-sectional view which shows typically the structure of the electrical power collector 20 for nonaqueous electrolyte secondary batteries which is another embodiment of this invention. FIG. 8 is a longitudinal sectional view schematically showing a method of manufacturing the current collector 20 for nonaqueous electrolyte secondary batteries shown in FIG. 7. FIG. 8: (a) is a longitudinal cross-sectional view which shows the state just after the metal foil 10 for electrical power collectors was supplied to the pressure welding nip part 8. FIG. FIG. 8 (b) is a longitudinal cross-sectional view showing a state where plastic deformation of the surface of the metal foil 10 for current collectors in the pressure welding nip portion 8 is in progress. FIG.8 (c) is a longitudinal cross-sectional view of the electrical power collector 20 after passing through a pressure welding nip part 8. FIG. FIG. 9 is a diagram schematically showing the configuration of the roller 28 used in the manufacturing method shown in FIG. 8. 9A is a perspective view showing the appearance of the roller 28. FIG. 9B is an enlarged perspective view of the surface area 28a of the roller 28. FIG. 9C is an enlarged perspective view of the concave portion 29 formed on the circumferential surface of the roller 28.

The current collector 20 includes a base portion 21 and a plurality of convex portions 22.

Like the current collector 1, the current collector 20 can be produced by compressing the current collector metal foil 10 by a pair of processing means and generating partial plastic deformation. Compression processing is given to one surface of the metal foil 10 for electrical power collectors. The details of compression processing will be described later.

In the case where the current collector 20 is used as the negative electrode current collector, the current collector 20 is made of the same material as the metal foil 10 for current collector when the current collector 1 is used as the negative electrode current collector. In the case where the current collector 20 is used as a positive electrode current collector, the current collector 20 is made of the same material as the metal foil 10 for current collector when the current collector 1 is used as a positive electrode current collector. .

The base material part 21 is formed in the sheet form, and the cross-sectional shape of the thickness direction is substantially rectangular. The thickness of the base material portion 21 is t ₅ . The thickness t ₅ is not particularly limited, but is preferably ₅ μm to 100 μm, more preferably 8 to 35 μm. If the thickness of the base part 21 is less than 5 micrometers, the mechanical strength of the electrical power collector 20 may become inadequate, and the handleability of the electrical power collector 20 at the time of electrode manufacture falls, and the electrode of the battery charges at the time of battery charging. Breakage is likely to occur. On the other hand, when the thickness of the base material portion 21 exceeds 100 µm, the mechanical strength of the current collector 20 is secured, but the volume of the current collector 20 occupies the entire electrode becomes large, and the battery can not sufficiently achieve high capacity. There is a case.

Since the surface 21a of the base material part 21 is subjected to the compression process as mentioned later, it has surface roughness different from the original metal foil 10 for electrical power collectors.

The some convex part 22 is formed in one surface of the thickness direction in the base material part 21. As shown in FIG. The convex portion 22 is formed to extend from the surface of the base portion 21 toward the outside of the base portion 21. The convex part 22 has a function which supports an active material layer on at least one part of the surface, for example.

The convex part 22 is formed by the plastic deformation accompanying compression processing of the base material part 21, without receiving a compression process. In addition, the tip surface of the convex part 22 was hardly affected by compression processing and plastic deformation. Therefore, the distal end surface of the convex portion 22 has a surface roughness almost the same as that of the original metal foil 10 surface for current collectors. The distal end surface of the convex portion 22 is a plane that is at the part farthest from the base portion 21 of the convex portion 22 in the direction in which the convex portion 22 extends or protrudes.

In addition, two adjacent convex parts 22 are formed so that spaced apart. Therefore, in the cross section of the thickness direction of the electrical power collector 20 shown in FIG. 7, between the two adjacent convex parts 22, the surface 21a of the base material part 21 exists as a recessed part.

The convex portion 22 has a tapered shape in the cross section of the current collector 20 in the thickness direction (hereinafter referred to simply as the “cross section of the convex portion 22”). In more detail, the cross section of the convex part 22 faces the direction which the convex part 22 extends from the surface of the base part 21, and the width | variety of the direction parallel to the surface of the base part 21 (hereinafter, simply referred to as 'convex'). The cross section width of the portion 22 'has a tapered shape that gradually or continuously decreases. In this embodiment, the cross section of the convex part 22 is substantially trapezoid shape. Since the convex part 22 has a tapered shape, after completion of compression processing, the releasability from the roller 28 of the current collector 20 is improved, and the deformation of the convex part 22 is prevented, and the convex part is prevented. Non-uniformity of the shape of (22) can be minimized.

In addition, in this embodiment, although the shape of the convex part 22 is conical trapezoid, if the cross section of the convex part 22 has a tapered shape, the shape of the convex part 22 will not be restrict | limited in particular. In addition, in this embodiment, although the front end surface of the convex part 22 becomes the plane substantially parallel to the surface of the base material part 21 in the direction which extends, the convex part 22 is not limited to this. For example, the surface which is not parallel to the surface of the base material part 21, the surface hemispherical shape with an unevenness | corrugation, a dome shape, etc. may be sufficient. These shapes are effective for increasing the bonding strength of the convex portion 22 and the active material layer.

7, from a point on the straight line that represents the front end surface of the convex portion 22, the length of the drawn down perpendicular to the line indicative of the surface that does not have the convex portion 22 of the substrate section 21 is formed t ₆ to be. t is _6, is formed with a convex portion 22 to be larger than the thickness t ₀ of the original current collector metallic foil (10). On the other hand, t ₆ can also be defined as the maximum thickness of the current collector 20.

Moreover, the boundary 22a of the base material part 21 and the convex part 22 in the surface 21a of the base material part 21 is comprised by the curved surface. Here, the boundary 22a also includes the vicinity of the boundary 22a. By making the boundary 22a a curved surface, even if a force acts on the convex part 22, it becomes possible to distribute stress, and the mechanical strength of the electrical power collector 20 increases. As a result, in the process of forming the convex part 22, the process of supporting an active material in the convex part 22, and manufacturing an electrode, local distortion, deformation, etc. can be prevented from occurring in the electrical power collector 20. have. Moreover, peeling, partial fall-out, etc. from the electrical power collector 20 of an active material layer can be suppressed in the process of slitting an electrode to a predetermined width | variety after electrode preparation.

8 is a longitudinal cross-sectional view for explaining the method for manufacturing the current collector 20 as described above. In the process shown in FIG. 8A, for example, in the current collector manufacturing apparatus 35 shown in FIG. 5, the same configuration except for using the roller 28 shown in FIG. 9 instead of the roller 4 is used. By using the current collector manufacturing apparatus that requires, the compression processing of the metal foil 10 for current collectors is performed.

As shown in Figs. 9A and 9B, the rollers 28 are provided with a plurality of recesses 29 in the circumferential surface thereof. As shown in Fig. 9 (c), the recess 29 has a curved opening edge 29a at the circumferential surface of the roller 28 of the recess 29, and the curved surface has a plurality of grooves ( 29x) is formed. The groove 29x is formed linearly in the direction toward the bottom of the recess 29 from the peripheral surface of the roller 28. Although the width | variety of the groove | channel 29x is not specifically limited, Preferably it is 1 micrometer or less. In addition, the depth of the groove 29x is not particularly limited, but is preferably 1 μm or less. On the other hand, the depth of the groove 29x is the length of the direction toward the axis line of the roller 28 from the surface of the opening edge 29a.

By using the roller 28 in which the recessed part 29 in which the opening edge 29a is comprised by the curved surface is used, the metal foil 10 and the roller 28 for electrical power collectors at the time of the compression processing of the metal foil 10 for electrical power collectors are carried out. Stress such as resistance force, friction force, etc. generated on the surface of the N-type is reduced, and the releasability from the roller 28 of the current collector 20 after the end of the compression processing is improved. Moreover, since the stress which partially plastically deforms the metal foil 10 for electrical power collectors is added gently and reliably, the convex part 22 can be formed reliably, and workability improves. As a result, while preventing local skew, deformation, etc. from occurring in the collector 20, the nonuniformity of the shape, height, etc. of the convex part 22 is remarkably reduced, and the convex part 22 is deformed. It is possible to form the convex portion 22 having an even dimension such as shape or height without making it.

In addition, by forming the some groove 29x in the opening edge 29a, the atmosphere which remains in the internal space of the recessed part 29 at the time of compression processing, the circumferential surface of the roller 29, and / or an electrical power collector Lubricant or the like applied to the surface of the metal foil 10 is discharged to the outside from the internal space of the recess 29 through the groove 29x. Thereby, in the internal space of the recessed part 29, the internal resistance which wants to inhibit the plastic deformation of the convex part 22 is reduced. As a result, the plastic deformation of the convex part 22 advances smoothly, the nonuniformity of the shape, the dimension, etc. of the convex part 22 becomes small, and the local nonuniformity of the mechanical strength of the obtained electrical power collector 20 becomes small. This effect is particularly remarkable when the width of the grooves 29x is 1 m or less and the depth is 1 m or less. If the width or depth of the groove 29x is too large, the residual atmosphere, the lubricant, and the like will easily come out, but there is a fear that the plastic deformation of the convex portion 22 may not proceed sufficiently.

In addition, the arrangement pattern of the recessed part 29 in the peripheral surface of the roller 28 is as follows in this embodiment. As shown in FIG.9 (b), the column in which the some recessed part 29 was arrange | positioned by the pitch Pc in the longitudinal direction of the roller 28 is set to one row unit 33. As shown to FIG. The plurality of row units 33 are arranged at a pitch Pd in the circumferential direction of the roller 28. The pitch Pc and the pitch Pd can be set arbitrarily. On the other hand, in the circumferential direction of the roller 28, the one row unit 33 and the adjacent row unit 33 are arranged so that the recessed part 29 may shift | deviate in the longitudinal direction of the roller 28. As shown in FIG. In this embodiment, although the shift | offset | difference of the longitudinal direction of the recessed part 29 is 0.5Pc, it is not limited to this, Arbitrary setting is possible. In addition, in this embodiment, although the shape of the opening part of the recessed part 29 in the circumferential surface of the roller 28 is almost circular, it is not limited to this, For example, it is almost elliptical, almost rectangular, nearly rhombic, It may be almost square, almost regular hexagon, nearly square octagon, or the like.

The roller 28 can be produced by processing the recessed formation roller used for manufacturing the roller 4, for example by etching, sand blasting, electric discharge processing, laser processing, or the like. The same method as the case of forming the roller 4 is used for laser processing.

When a recess is formed in the recess circumferential surface of the recess forming roller by laser and processing, a ridge not shown in the opening edge 29a on the recess circumferential surface of the recess forming roller is generated. By removing this ridge, the recessed part 29 in which the opening edge 29a was formed in the curved surface is formed, and the roller 28 is obtained. Removal of bumps is preferably performed by polishing using diamond particles. As the diamond particles, those larger than the minimum size of the concave portion 29 are preferably used. More preferably, the average particle diameter of diamond grains is 30 micrometers or more and less than 35 micrometers. Here, the size of the recessed part 29 means the opening diameter of the recessed part 29 in the roller 28 circumferential surface. By using such diamond grains having an average particle diameter, the opening edge 29a is formed of a curved surface with a large radius of curvature, and peeling from the base portion 21 of the convex portion 22 can be prevented more remarkably. . In addition, the diamond particles are prevented from being buried inside the recess 29.

On the other hand, polishing using diamond particles can be carried out in the same manner as in general polishing methods, except that diamond particles are used as abrasive particles or grinding particles. Usually, it carries out by the grinding | polishing machine with a polishing pad, putting a diamond particle on a grinding | polishing surface, and supplying media, such as water.

Formation of the groove 29x on the surface of the opening edge 29a is preferably performed by polishing with diamond particles having an average particle diameter of 5 µm or less. Thereby, the groove 29x of width 1 micrometer or less and depth 1 micrometer or less can be formed easily. The grooves 29x may be formed after the removal of the ridges or may be performed simultaneously with the removal of the ridges. On the other hand, since the diamond particle used here is very small in particle diameter, it is hard to be buried inside the recessed part 29, and can be easily removed by washing after formation of the groove 29x.

The peripheral surface of the roller 28 thus obtained and the surface facing the internal space of the concave portion 29, like the roller 4, contain a coating layer containing a cemented carbide, a coating layer containing alloy pores, and chromium oxide. One or two or more of a coating layer, a protective layer containing an amorphous carbon material, and a coating layer made of ceramics may be formed. Thereby, the same effect as forming such a coating layer and a protective layer in the roller 4 can be acquired.

The roller 28 is arrange | positioned so that the circumferential surface may be press-contacted to the circumferential surface of the roller 5, and the axis line may become parallel with the axis line of the roller 5, and it forms the press-contact nip part 34. As shown in FIG.

In the process shown in FIG. 8A, the current collector metal foil 10 is supplied to the pressure-contacting nip portion 34, and pressing forces 30a and 30b in the thickness direction of the current collector metal foil 10 are added. do.

In the process shown in FIG.8 (b), the contact surface which contact | connects the peripheral surface of the roller 28 is compressed by the pressing force 30a, 30b among the surfaces which oppose the peripheral surface of the roller 28 of the metal foil 10 for electrical power collectors. The processing is carried out so that the non-contact surface that does not contact the peripheral surface of the roller 28 and faces the recess 29 is not subjected to compression processing. There is a contact surface around the noncontact surface. That is, the contact surface is subjected to compression processing, whereby the thickness on the contact surface is smaller than the thickness of the metal foil 10 for current collectors, whereby raised portions 21x are formed in which the base portion 21 is circular. do. On the other hand, in the non-contact surface, stresses 31a and 31b are directed from the periphery of the non-contact surface toward the bottom of the recess 29 along the surface of the non-contact surface toward the internal space of the recess 29. . Thereby, plastic deformation of a non-contact surface starts to rise, it protrudes toward the bottom of the recessed part 29, and the convex part 22x is formed. At the same time, the boundary between the ridge 21x and the convex portion 22x is formed into a curved shape along the opening edge 29a of the recess 29. At this time, since the volume of the convex portion 22x is less than 50% of the volume of the internal space of the concave portion 29, the pressurization is continued.

In the step shown in FIG. 8C, the current collector 20 is obtained. In the current collector 20, the boundary portion 22a of the base portion 21 and the convex portion 22 is formed of a curved surface. Up to the roller 28 and the pressing by the roller (5) is, preferably, a base portion 21 thickness t ₅ is small, and the collector (20) than the thickness t ₀ of the metal foil 10 for the current collector of the thickness t ₆ is made until greater than the thickness t ₀ of the metal foil for the current collector (10). More preferably, the pressurization is performed until the volume of the convex portion 22 is 50% or more, preferably 50 to 85% of the volume of the internal space of the concave portion 29. If it is less than 50%, the height of the convex part 29 will become inadequate and there exists a possibility that carrying out of an active material cannot be carried out smoothly. In addition, there is a possibility that after the active material is supported, the possibility of the active material peeling off and falling off from the current collector 20 increases. On the other hand, if it exceeds 85%, the air remaining in the concave portion 29, the vapor of the lubricant, and the like are compressed to increase the internal pressure, thereby inhibiting the smooth plastic deformation of the convex portion 22, Unevenness in shape may occur.

In the current collector 20, the surface 21a on which the convex portion 22 of the base material portion 21 is not formed has a surface roughness different from that of the metal foil 10 for current collector because compression processing is performed. . Since the front end surface of the convex part 22 is not subjected to compression processing and the influence of plastic deformation is very small, it has almost the same surface roughness as the metal foil 10 for electrical power collectors. In addition, although the side surface of the convex part 22 is not subjected to compression processing, since it is influenced by plastic deformation, it has surface roughness near the metal foil 10 for electrical power collectors. Therefore, by supporting the active material layer on the surface of the convex portion 22, preferably the tip surface, the active material layer in the charge / discharge cycle is prevented from peeling off from the current collector 20 and falling off.

FIG. 10: is a longitudinal cross-sectional view which shows typically the structure of the electrical power collector 23 for nonaqueous electrolyte secondary batteries of another form. FIG. 11 is a longitudinal sectional view schematically showing the method of manufacturing the current collector 23 shown in FIG. 10. FIG. 11: (a) is a longitudinal cross-sectional view which shows the state immediately after the metal foil 10 for electrical power collectors was supplied to the pressure welding nip part 34a. FIG. 11 (b) is a longitudinal cross-sectional view showing a state where plastic deformation of the surface of the metal foil 10 for current collectors in the pressure welding nip portion 34a is in progress. FIG. 11C is a longitudinal cross-sectional view showing a state immediately after the current collector 23 is formed in the pressure welding nip portion 34a.

The current collector 23 has the same configuration as the current collector 20 except that a plurality of convex portions 25x and 25y are formed on both surfaces in the thickness direction of the substrate portion 24. That is, the base material part 24 is the same structure as the base material part 21. FIG. The convex parts 25x and 25y have the same structure as the convex part 22. The convex part 25x is formed so that it may protrude toward the outer side of the base material part 24 from one surface in the thickness direction of the base material part 24, or protrude. The convex part 25y is formed so that it may protrude toward the outer side of the base material part 24 from the other surface in the thickness direction of the base material part 24, or protrude. The direction in which the convex portion 25x extends and the direction in which the convex portion 25y extends are reverse.

In the current collector 23, the boundary portion 25a of the base portion 24 and the convex portions 25x and 25y is formed of a curved surface. Thereby, the same effect as the boundary part 22a in the electrical power collector 20 is comprised by the curved surface can be acquired.

In the cross section in the thickness direction of the current collector 23, the line showing the front end surfaces of the convex portions 25x and 25y is substantially parallel to the line showing the surface 24a of the base material portion 24. Since the tip surfaces of the convex portions 25x and 25y are almost flat surfaces and are not subjected to compression processing, they have almost the same surface roughness as the metal foil 10 for the current collector, which is a raw material. Side surfaces of the convex portions 25x and 25y are not subjected to compression processing, but are affected by plastic deformation, and therefore have surface roughness close to that of the metal foil 10 for current collectors. Therefore, by supporting the active material layer on the surface of the convex portion 22, preferably the tip surface, the active material layer in the charge / discharge cycle is prevented from peeling off from the current collector 20 and falling off.

Further, in the collector 23, the thickness t ₇ of the base portion 24 is formed to be smaller than the thickness t ₀ of the metallic foil 10 for a current collector as a raw material. Further, the thickness t ₈ in the front end surface of the raised portion (25x) to the front end surface of the raised portion (27y) is formed to be larger than the thickness t ₀ of the metal foil for the current collector (10). The thickness t ₈ can also be defined as the maximum thickness of the current collector 23. By configuring in this way, the mechanical strength of the electrical power collector 23 becomes high, and solvent resistance increases.

The current collector 23 is, for example, in the current collector manufacturing apparatus 35 shown in FIG. 5, the current collector requiring the same configuration except for using two rollers 28 instead of the rollers 4, 5. It can manufacture using a manufacturing apparatus.

FIG. 11 is a longitudinal cross-sectional view for explaining the method for manufacturing the current collector 23 as described above.

In the process shown to FIG. 11 (a), an electrical power collector is provided in the contact welding nip part 34a formed by arrange | positioning two roller 28 so that the circumferential surface of each other may be press-contacted and the axis line of each other may be parallel. The metal foil 10 for supply is supplied. As for the metal foil 10 for electrical power collectors, the pressing force 30a, 30b of the thickness direction is added.

In the process shown in FIG.11 (b), the contact surface which contact | connects the peripheral surface of the roller 28 is compressed by the pressing force 30a, 30b among the surfaces which oppose the peripheral surface of the roller 28 of the metal foil 10 for electrical power collectors. Processing is carried out. On the other hand, compression processing is not performed on the non-contact surface that does not contact the peripheral surface of the roller 28 and faces the recess 29, but plastic deformation occurs in accordance with the compression processing of the contact surface. There is a contact surface around the noncontact surface. That is, as the contact surface is subjected to compression processing, the thickness on the contact surface is smaller than the thickness of the metal foil 10 for the current collector, so that a raised portion 24x that becomes a circle of the base portion 24 is formed. On the other hand, the non-contact surface is stressed 31a, 31b, 31x, 31y from the periphery of the non-contact surface toward the bottom of the recess 29 along the surface facing the internal space of the recess 29 in accordance with the pressure on the contact surface. ) Is added. Thereby, plastic deformation inside a non-contact surface advances and it protrudes toward the bottom of the recessed part 29, and convex parts 32x and 32y are formed. At the same time, the boundary between the raised portions 24x and the convex portions 32x and 32y is formed in a curved shape along the opening edge 29a of the recessed portion 29. At this point in time, since the volumes of the convex portions 32x and 32y are less than 50% of the volume of the internal space of the concave portion 29, the pressurization continues.

In the step shown in FIG. 11C, the current collector 23 is obtained. In the current collector 20, the boundary portion 25a of the base portion 24 and the convex portions 25x and 25y is formed of a curved surface. Pressurization by the two rollers 28 is preferably, the thickness t ₇ of the base material portion 24 is smaller than the thickness t ₀ of the metal foil 10 for current collector, and the maximum thickness t ₈ of the current collector 23. Is made larger than the thickness t ₀ of the metal foil 10 for current collectors. The pressurization is more preferably performed until the volume of the convex portions 25x and 25y is 50% or more, preferably 50 to 85% of the volume of the internal space of the concave portion 29. If it is less than 50%, the height of the convex part 29 will become inadequate and there exists a possibility that carrying out of an active material cannot be carried out smoothly. In addition, there is a possibility that after the active material is supported, the possibility of the active material peeling off and falling off from the current collector 20 increases. On the other hand, if it exceeds 85%, the air remaining in the recess 29, the vapor of the lubricant, and the like are compressed to increase the internal pressure, and there is a concern that irregularities in shape may occur in the convex portions 25x and 25y.

In the present embodiment, the current collectors 1, 15, 20, and 23 of the present invention are manufactured, and the current collector manufacturing apparatus 35 or the similar current collector manufacturing apparatus shown in FIG. 5 is used. It does, but is not limited to it. For example, using a metal mold | die, such as a die-set metal mold | die which formed the recessed part which has a shape corresponding to a convex part, it clamps the collector metal foil 10 from both surfaces of the thickness direction, and pressurizes with this metal mold | die. It becomes possible to give the compression process of this invention to the metal foil 10 for electrical power collectors by this. Accordingly, the current collectors 1, 15, 20, and 23 of the present invention can be manufactured.

Moreover, although the electrical power collector obtained by the manufacturing method of this invention can be used suitably as an electrical power collector for nonaqueous electrolyte secondary batteries, it is not limited to this, For example, secondary batteries other than nonaqueous electrolyte secondary batteries, lithium primary batteries, etc. It can also be used as a collector for primary batteries.

[Manufacturing Method of Electrode for Nonaqueous Electrolyte Secondary Battery]

The manufacturing method of the electrode for nonaqueous electrolyte secondary batteries of this invention can be implemented similarly to the manufacturing method of the conventional electrical power collector except using the electrical power collector manufactured by the manufacturing method of this invention as an electrical power collector. For example, an active material layer can be supported on the surface of an electrical power collector by apply | coating an electrode mixture slurry to the surface of the electrical power collector manufactured by the manufacturing method of this invention, and drying. In addition, a thin film-like active material layer may be formed on the surface of the current collector.

The convex part of the electrical power collector obtained by the manufacturing method of this invention is formed without receiving a compression process. Moreover, since the convex part surface is not influenced by compression processing, and especially the front end surface of the convex part is formed with little influence of plastic deformation, processing distortion etc. do not remain. Therefore, when the thin film of an active material layer is formed on the surface of the electrical power collector obtained by the manufacturing method of this invention, a thin film with high precision and uniform thickness can be formed. Moreover, since the surface roughness of a convex part, especially the front end surface of a convex part maintains the surface roughness of the metal foil before a process, the adhesive force of the thin film which is an active material layer, and an electrical power collector surface improves. On the other hand, this effect becomes especially remarkable when an active material layer is formed in the electrical power collector in which the boundary part of a base material part and a convex part is comprised by the curved surface.

The electrode mixture slurry includes a positive electrode mixture slurry and a negative electrode mixture slurry. First, the production of a positive electrode using the positive electrode mixture slurry will be described. The positive electrode mixture slurry contains a positive electrode active material and a solvent, and again contains a positive electrode binder, a conductive material, and the like as necessary.

As the positive electrode active material, those commonly used in the field of nonaqueous electrolyte secondary batteries can be used. For example, lithium cobalt oxide and its modified body (such as lithium cobaltate dissolved in aluminum or magnesium), lithium nickel acid and its modification And composite oxides such as a sieve (a part of nickel substituted with cobalt), lithium manganate, and a modified substance thereof. A positive electrode active material can be used individually by 1 type, or can be used in combination of 2 or more type.

As the binder for the positive electrode, those commonly used in the field of nonaqueous electrolyte secondary batteries can be used, and examples thereof include polyvinylidene fluoride (PVdF), modified polyvinylidene fluoride, polytetrafluoroethylene (PTFE), and acrylate units. The rubber particle binder which has a etc. is mentioned. Along with such a positive electrode binder, an acrylate monomer or an acrylate oligomer having a reactive functional group may be used. The binder for positive electrodes can be used individually by 1 type, or can be used in combination of 2 or more type.

As the conductive material, those commonly used in the field of nonaqueous electrolyte secondary batteries can be used, and examples thereof include carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black, and various graphites. have. A conductive material can be used individually by 1 type, or can be used in combination of 2 or more type.

A positive electrode mixture slurry is produced by, for example, dispersing a positive electrode active material, a binder for a positive electrode, a conductive material, and the like in a suitable dispersion medium, and adjusting the viscosity to a suitable viscosity for application to a current collector, if necessary. As a dispersion medium, water, organic solvents, such as 2-methyl-N-pyrrolidone, etc. can be used. General dispersion machines, such as a planetary mixer, can be used for dispersion of solid content, such as a positive electrode active material, in the solvent.

A positive electrode plate is obtained by apply | coating this positive electrode mixture slurry to the surface of one or both sides of a positive electrode electrical power collector, drying it, and performing press molding as needed, and adjusting to predetermined thickness. The thickness of the positive electrode current collector is not particularly limited, but is preferably 5 to 30 μm. For application of the positive electrode mixture slurry to the positive electrode current collector, a general coating device such as a die coater can be used. In addition, a drying temperature is suitably selected according to the kind of solvent mainly.

Next, the production of the negative electrode using the negative electrode mixture slurry will be described. The negative electrode mixture slurry contains a negative electrode active material and a dispersion medium, and further contains a negative electrode binder, a conductive material, and the like as necessary.

As an active material for negative electrodes, what is commercially available in the field of a nonaqueous electrolyte secondary battery can be used, For example, graphite materials, such as various natural graphite and artificial graphite, silicon-based composite materials, such as a silicide, various alloy materials, etc. can be used. A negative electrode active material can be used individually by 1 type, or can be used in combination of 2 or more type.

As the negative electrode binder, those commonly used in the field of nonaqueous electrolyte secondary batteries can be used. For example, carboxymethylcellulose (PVDF) and its modified product, styrene-butadiene copolymer rubber (SBR) particles and its modified product can be used. Cellulose resins such as CMC). The binder for negative electrodes can be used individually by 1 type, or can be used in combination of 2 or more type. In particular, the mixture of SBR particle | grains and cellulose resin, the mixture which added the small amount of cellulose resin to SBR particle | grains, etc. are preferable. Using such a mixture improves lithium ion acceptability etc., for example.

As the conductive material, the same ones used for the positive electrode can be used.

Preparation of a negative electrode mixture slurry can be performed similarly to preparation of a positive electrode mixture slurry. In addition, as a dispersion medium which disperse | distributes a negative electrode active material, organic solvents, such as water and 2-methyl- N-pyrrolidone, etc. can be used, for example.

A negative electrode plate is obtained by apply | coating this negative electrode mixture slurry to one or both surfaces of the negative electrode electrical power collector, making it dry, press molding as needed, and adjusting to predetermined thickness. Although the thickness in particular of a negative electrode collector is not restrict | limited, Preferably it is 5-25 micrometers. For application to the current collector of the negative electrode mixture slurry, for example, a general coating device such as a die coater can be used. In addition, a drying temperature is suitably selected according to the kind of solvent mainly.

In order to form a thin film-like active material layer on the surface of the current collector, a vacuum process can be suitably used, and among them, a vapor deposition method, a sputtering method, a chemical vapor deposition method (CVD method) and the like are preferable. For example, the deposition of the active material on the surface of the current collector is performed using, for example, a general vapor deposition apparatus. According to the vacuum deposition process, the active material layer can be selectively formed in a predetermined portion of the current collector. Although it does not specifically limit as a vapor deposition apparatus, The vacuum vapor deposition apparatus of the system provided with the electron beam heating means, heating and vaporizing an active material by an electron beam heating means, and making this vapor adhere to the surface of an electrical power collector is preferable. Such a vacuum vapor deposition apparatus is marketed from Arubak Co., Ltd., for example. In the case of performing vapor deposition, mainly an active material is vapor-deposited.

In the case of performing vapor deposition, a negative electrode active material is preferable as an active material. As the negative electrode active material, for example, Si, Sn, Ge, Al, an alloy containing one or more of these, oxides such as SiOx, SnOx, sulfides such as SiSx, SnS and the like can be used. The negative electrode active material layer is preferably formed in a columnar shape on the surface of the negative electrode current collector, preferably on the front surface of the convex portion of the negative electrode current collector. It is preferable that a negative electrode active material layer contains an amorphous or low crystalline negative active material.

The thickness of the active material layer formed on the surface of the current collector, preferably the surface of the convex portion, and more preferably, the front surface of the convex portion, depends on the type of active material, the method of forming the active material layer, the characteristics required for the finally obtained nonaqueous electrolyte secondary battery, Although it can select suitably according to various conditions, such as the use of the said battery, Preferably it is 5-30 micrometers, More preferably, it is 10-25 micrometers.

[Non-aqueous electrolyte secondary battery]

The nonaqueous electrolyte secondary battery of this invention contains the electrode of this invention, its counter electrode, and the lithium ion conductive nonaqueous electrolyte. That is, the nonaqueous electrolyte secondary battery of this invention is a nonaqueous electrolyte lithium secondary battery. When the nonaqueous electrolyte secondary battery of the present invention includes the electrode of the present invention as a negative electrode, the structure of the positive electrode is not particularly limited. In addition, when the nonaqueous electrolyte secondary battery of the present invention includes the electrode of the present invention as a positive electrode, the structure of the negative electrode is not particularly limited. On the other hand, the electrode of the present invention is preferably used as a cathode.

12 is a partially exploded perspective view schematically showing the configuration of a nonaqueous electrolyte secondary battery 40 which is one of the embodiments of the present invention. The nonaqueous electrolyte secondary battery 40 includes an electrode group 41, a positive electrode lead 42, a negative electrode lead (not shown), an insulating plate 44, a sealing plate 45, a gasket 46, and a battery case 47. do.

The electrode group 41 includes the positive electrode 50, the negative electrode 51, and the separator 52. The positive electrode 50, the separator 52, the negative electrode 51, and the separator 52 are stacked in this order. It wound and formed in spiral shape. The electrode group 41 contains an electrolyte (not shown).

The positive electrode 50 includes the positive electrode current collector and the positive electrode active material layer (not shown) when the positive electrode 50 is the electrode of the present invention or the negative electrode 51 is the electrode of the present invention.

As a positive electrode current collector, what is commercially available in this field can be used, For example, foil, a nonwoven fabric, etc. which consist of aluminum, an aluminum alloy, stainless steel, titanium, etc. are mentioned. The thickness of the positive electrode current collector is not particularly limited, but is preferably 5 μm to 30 μm.

The positive electrode active material layer is formed on one or both surfaces in the thickness direction of the positive electrode current collector, contains a positive electrode active material, and includes a conductive material and a binder as necessary. As the positive electrode active material, it is possible to use a lithium-containing transition metal oxide, such as MnO ₂ to the metal oxide not containing lithium such as exemplified above.

As the conductive material, those commonly used in this field can be used, and for example, graphite of natural graphite, artificial graphite, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black and the like, carbon black Conductive fibers such as fibers and metal fibers, metal powders such as carbon fluoride and aluminum, conductive whiskers such as zinc oxide and potassium titanate, conductive metal oxides such as titanium oxide, and organic conductive materials such as phenylene derivatives. have

As the binder, for example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene, polyethylene, polypropylene, aramid resin, polyamide, polyimide, polyamideimide, polyacrylonitrile, polyacrylic acid, polyacrylic acid methyl ester , Polyacrylic acid ethyl ester, polyacrylic acid hexyl ester, polymethacrylic acid, polymethacrylic acid methyl ester, polymethacrylic acid ethyl ester, polymethacrylic acid hexyl ester, polyvinyl acetate, polyvinylpyrrolidone, polyether, And polyether sulfone, hexafluoropolypropylene, styrene butadiene rubber, carboxymethyl cellulose, and rubber particle binder containing acrylate units. In addition, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, pentafluoropropylene, fluoromethyl vinyl ether, acrylic acid, hexadiene, reactive functional groups You may use as a binder the copolymer which consists of 2 or more types of monomer compounds chosen from the containing acrylate monomer, the acrylate oligomer containing a reactive functional group, etc.

The positive electrode 50 is manufactured as follows, for example. First, a positive electrode mixture slurry is prepared by mixing and dispersing a positive electrode active material, a conductive material, a binder, and the like into a dispersion medium as necessary. As the dispersion medium, for example, a dispersion medium commonly used in this field such as N-methyl-2-pyrrolidone can be used. General dispersers, such as a planetary mixer, can be used for mixing and disperse | distributing to dispersion mediums, such as a positive electrode active material, for example. The positive electrode mixture slurry thus obtained is applied to one or both surfaces of the positive electrode current collector, dried and rolled to a predetermined thickness to form a positive electrode active material layer, thereby obtaining a positive electrode 50.

The negative electrode 51 is an electrode of the present invention, or when the positive electrode 50 is an electrode of the present invention, a negative electrode current collector and a negative electrode active material layer (not shown) are included.

As a negative electrode current collector, what is commercially available in this field can be used, For example, metal foil, a metal film, etc. which consist of copper, nickel, iron, the alloy containing at least 1 among these, etc. are mentioned. Among these, metal foil, a metal film, etc. which consist of copper or a copper alloy are preferable. As the copper alloy, a copper alloy can be used as exemplified earlier in the present specification. When metal foil of copper and a copper alloy is taken as an example, electrolytic copper foil, an electrolytic copper alloy foil, a rolled copper foil, a copper alloy foil, a rolled copper alloy foil, the foil which carried out the roughening process to these, etc. are mentioned, for example. . As foil which performed the roughening process, electrolytic copper foil, rolled copper foil, copper alloy foil, etc. are preferable.

Although the thickness of a negative electrode collector is not specifically limited, Preferably it is 5 micrometers-100 micrometers, More preferably, it is 8-35 micrometers. If the thickness of the negative electrode current collector is less than 5 µm, the mechanical strength of the negative electrode current collector may be insufficient, and the handleability at the time of electrode production is lowered.

In addition, breakage of the electrode or the like during battery charging is likely to occur. On the other hand, when the thickness of the negative electrode current collector exceeds 100 µm, the mechanical strength is secured, but the volume of the negative electrode current collector occupied in the entire electrode becomes large, so that high capacity of the battery may not be sufficiently achieved.

The negative electrode active material layer is formed on one or both surfaces in the thickness direction of the negative electrode current collector, contains a negative electrode active material, and includes a conductive material, a binder, a thickener, and the like as necessary. As the negative electrode active material, for example, various natural graphites, graphite materials such as artificial graphite, silicon-based composite materials such as silicide, alloy negative electrode active materials, and the like can be used. As the conductive material, the same ones as those added to the positive electrode active material layer can be used. As a binder, the same thing as what is added to a positive electrode active material layer can be used. Moreover, styrene-butadiene copolymer rubber particle (SBR), its modified body, etc. can be used as a binder from a viewpoint of lithium ion acceptability improvement.

As the thickener, those commonly used in this field can be used. Among them, those having water solubility and being viscous in the form of aqueous solution are preferable. For example, cellulose-based resins such as carboxymethyl cellulose (CMC) and modified substances thereof, polyethylene oxide (PEO), and polyvinyl alcohol (PVA) ), And the like. Among these, a cellulose resin and its modified body are especially preferable from a viewpoint of dispersibility, thickening, etc. of the negative electrode mixture slurry mentioned later.

The negative electrode 51 can be produced in the same manner as the positive electrode 50 except for preparing a negative electrode mixture slurry by mixing and dispersing a negative electrode active material and a conductive material, a binder, a thickener, and the like in a dispersion medium.

As the separator 52, one commonly used in the field of nonaqueous electrolyte secondary batteries can be used. For example, it is generally preferable to use a single or a combination of polyolefin microporous films such as polyethylene and polypropylene. Do. More specifically, the separator 52 includes a porous membrane made of synthetic resin. As synthetic resin, polyolefin, such as polyethylene and polypropylene, aramid resin, polyamideimide, polyphenylene sulfide, polyimide, etc. are mentioned, for example. Examples of the porous membrane include a microporous membrane and a nonwoven fabric.

In addition, the separator 52 may contain heat-resistant fillers, such as alumina, magnesia, silica, titania, etc. in the inside or the surface. The heat-resistant layer may be formed on both surfaces or one surface of the separator 52 in the thickness direction. The heat resistant layer contains the heat resistant filler and the binder, for example. As the binder, the same one used for the positive electrode active material layer can be used. The thickness of the separator 17 is not particularly limited, but is preferably 10 µm to 30 µm, more preferably 10 to 25 µm.

As the nonaqueous electrolyte, a polymer electrolyte or a solid electrolyte containing an electrolyte solution in which a solute is dissolved in an organic solvent, a solute and an organic solvent, and non-fluidized with a high molecular compound can be used. When using an electrolyte solution, it is preferable to impregnate the electrolyte solution in the separator 17. In addition, the nonaqueous electrolyte may contain an additive other than a solute, an organic solvent, and a high molecular compound.

The solute is selected based on the redox potential of the active material and the like. Specifically, as the solute, it is possible to use the solute that are commonly used in the field of lithium batteries, for _{example, LiPF 6, LiBF 4, LiClO} 4, LiAlCl 4, LiSbF 6, LiSCN, LiCF 3 SO 3, LiN (CF 3 CO ₂ ), LiN (CF ₃ SO ₂ ) ₂ , LiAsF ₆ , LiB ₁₀ Cl ₁₀ , lower aliphatic lithium carbonate, LiF, LiCl, LiBr, LiI, chloroborane lithium, bis (1,2-benzenediolate (2- ) -O, O ') lithium borate, bis (2,3-naphthalenediolate (2-)-O, O') lithium borate, bis (2,2'-biphenyldioleate (2-)-O, Borate, such as O ') lithium borate, bis (5-fluoro-2-oleate-1-benzenesulfonic acid-O, O') lithium borate, (CF ₃ SO ₂ ) ₂ NLi, LiN (CF ₃ SO ₂ (C ₄ F ₉ SO ₂ ), (C ₂ F ₅ SO ₂ ) ₂ NLi, lithium tetraphenyl borate and the like. A solute may be used individually by 1 type, or may use 2 or more types together as needed.

As the organic solvent, an organic solvent commonly used in the field of a lithium battery can be used. For example, ethylene carbonate (EC), propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate (DMC), diethyl carbonate, Ethyl methyl carbonate (EMC), dipropyl carbonate, methyl formate, methyl acetate, methyl propionate, ethyl propionate, dimethoxymethane, γ-butyrolactone, γ-valerolactone, 1,2-diethoxyethane, 1, 2 -Tetrahydrofran derivatives such as dimethoxyethane, ethoxymethoxyethane, trimethoxymethane, tetrahydrofran, 2-methyltetrahydrofran, dimethyl sulfoxide, 1,3-dioxolane, 4-methyl-1 Dioxolane derivatives such as, 3-dioxolane, formamide, acetamide, dimethylformamide, acetonitrile, propylnitrile, nitromethane, ethyl monograms, phosphate triesters, acetate esters, propionic acid esters Le, sulfolane, 3-methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, propylene carbonate derivative, ethyl ether, diethyl ether, 1,3-propane Sultone, anisole, fluorobenzene and the like. An organic solvent can be used individually by 1 type, or can use 2 or more types together as needed.

As the additive, for example, vinylene carbonate, cyclohexylbenzene, biphenyl, diphenyl ether, vinyl ethylene carbonate, divinyl ethylene carbonate, phenyl ethylene carbonate, diallyl carbonate, fluoroethylene carbonate, catechol carbonate, vinyl acetate, Additives, such as ethylene sulfite, propanesultone, trifluoropropylene carbonate, dibenzoprene, 2, 4- difluoro anisole, o-terphenyl, and m-terphenyl, may be included. An additive may be used individually by 1 type, or may use 2 or more types together as needed.

On the other hand, the nonaqueous electrolyte is one kind or a mixture of two or more kinds of polymer materials such as polyethylene oxide, polypropylene oxide, polyphosphazene, polyaziridine, polyethylene sulfide, polyvinyl alcohol, polyvinylidene fluoride and polyhexafluoropropylene. The solute may be mixed and the like and used as a solid electrolyte. It may also be mixed with the organic solvent and used in a gel state. Lithium nitride, lithium halide, lithium oxyacid, Li ₄ SiO ₄ , Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₄ SiO ₄ , Li ₂ SiS ₃ , Li ₃ PO ₄ -Li ₂ S Inorganic materials such as -SiS ₂ and phosphorus sulfide compounds may be used as the solid electrolyte. When using a solid electrolyte or a gel electrolyte, you may arrange | position between the positive electrode 50 and the negative electrode 51 instead of these separators 17. Alternatively, the gel electrolyte may be disposed adjacent to the separator 52.

As the positive electrode lead 42, the negative electrode lead, the insulating plate 44, the sealing plate 45, the gasket 46, and the battery case 47, any one commonly used in the field of the nonaqueous electrolyte secondary battery can be used. On the other hand, the positive electrode terminal 53 is provided in the center part of the sealing plate 45.

The nonaqueous electrolyte secondary battery 40 of the present invention is produced, for example, as follows. One end of each of the positive electrode lead 42 and the negative electrode lead is electrically connected to the positive electrode current collector of the positive electrode 50 and the negative electrode current collector of the negative electrode 51. The electrode group 41 is accommodated in the bottomed cylindrical battery case 47 together with the insulating plate 44. The other end of the negative electrode lead drawn from the lower part of the electrode group 41 is connected to the bottom of the battery case 47, and then the positive electrode lead 42 drawn from the upper part of the electrode group 41 is sealed plate 45. The non-aqueous electrolyte (not shown) of a predetermined amount is poured into the battery case 47 by connecting to. Next, the sealing plate 45 with the gasket 46 attached to the circumferential edge is inserted into the opening of the battery case 47, and the opening of the battery case 47 is folded inward to be caulked and sealed. An electrolyte secondary battery 40 is obtained.

FIG. 13: is sectional drawing which shows typically the structure of the laminated battery 55 which is one of embodiment of this invention. The stacked battery 55 includes a positive electrode 56, a negative electrode 57, a separator 58, a battery case 59, a positive electrode lead 60, a negative electrode lead 61, and a sealing resin 62. do. The positive electrode 56 includes a positive electrode current collector 56a and a positive electrode active material layer 56b formed on one surface in the thickness direction of the positive electrode current collector 56a. The negative electrode 57 includes a negative electrode current collector 57 a and a negative electrode active material layer 57 b formed on one surface in the thickness direction of the negative electrode current collector 57 a. The positive electrode 56 and the negative electrode 57 are provided to face each other with the separator 58 interposed therebetween. That is, in the stacked battery 55, the positive electrode 56, the separator 58, and the negative electrode 57 are stacked in this order and stacked to form a flat electrode group. The positive electrode 56, the negative electrode 57, and the separator 58 have the same configurations as the positive electrode 50, the negative electrode 51, and the separator 52 in the nonaqueous electrolyte secondary battery 40, respectively.

The battery case 59 is a container-shaped member having two openings, and houses an electrode group in its inner space. The two openings of the battery case 59 are sealed by sandwiching the sealing resin 62, respectively. One end of the positive electrode lead 60 is electrically connected to the positive electrode current collector 66a, and the other end thereof is led out of the battery 55 from one opening of the battery case 59. One end of the negative electrode lead 61 is electrically connected to the negative electrode current collector 57a, and the other end thereof is led out of the battery 55 from the other opening of the battery case 59. In the stacked battery 55, the same nonaqueous electrolyte as in the nonaqueous electrolyte secondary battery 40 can be used.

As described above, the nonaqueous electrolyte secondary battery of the present invention includes, for example, a rectangular battery having an electrode group wound in a spiral shape, a cylindrical battery having an electrode group wound in a spiral shape, a stacked battery having a stacked electrode group, and the like. There are three forms that can be adopted.

According to the manufacturing method of the electrical power collector and electrode plate for non-aqueous secondary batteries which concern on this invention, while ensuring the intensity | strength of the electrical power collector for manufacturing an electrode plate, an electrode active material is efficiently carried out on the convex part formed on the electrical power collector. Since a non-aqueous secondary battery with high reliability can be obtained, it is useful as a power supply for portable electronic devices, etc., in which high capacity is desired in addition to multifunctional electronic devices and communication devices.

EXAMPLE

An Example and a comparative example are given to the following, and this invention is concretely demonstrated to it.

(Example 1)

(Production of the collector for the negative electrode)

Using the current collector manufacturing apparatus 35 shown in FIG. 3, the negative electrode current collector 1 of the present invention was produced as follows. The roller 4 is a cemented carbide roller having a diameter of 50 mm, and the concave portion 4a was formed on the circumferential surface thereof in the arrangement pattern shown in Fig. 5A. The opening diameter of the recessed part 4a was 10 micrometers, and the depth was 8 micrometers. When the recesses 4a were formed by laser processing, raised portions were generated at the edges of the openings of the recesses 4a, which were removed by polishing. The roller 5 was an iron roller of diameter 50mm with a flat peripheral surface. The pressure contact pressure in the pressure welding nip part 6 of the roller 4 and the roller 5 was 10 kN in linear pressure.

The thickness t ₀ was equipped with a current collector of copper foil for 18㎛, a metal foil supply roller 36 and the winding, a current collector manufacturing apparatus 35 shown in Fig. 3 in. The copper foil for current collector is supplied to the press-contacting nip part 6 of the processing means 7, and it performs a partial uncompression process on copper foil, and consists of the base part 2 and the convex part 3, FIG. The current collector 1 shown in (c) was produced, and wound on a winding-up roller 38. t ₁ is 17㎛, t ₂ was 21㎛. That is, t ₂ > t ₀ > t ₁ .

On the other hand, in the electrical power collector 1, the surface which opposes the recessed part 4a of the peripheral surface of the roller 4 is plastically deformed according to the compression process of another part, and the convex part 3 is formed. On the other hand, the convex part was not formed in the surface which the circumferential surface opposes the flat roller 5, and became a flat surface.

The cross section of the thickness direction of the electrical power collector 1 obtained here was observed with the scanning electron microscope. 18 is an electron micrograph of a cross section of the current collector 1. From Fig. 18, it is clear that the current collector 1 has no defects such as corrugated wrinkles, warpage, and wrinkles.

(Production of the cathode)

The current collector 1 obtained above was mounted in the vacuum vapor deposition apparatus provided with the electron beam heating means. As a target, vapor deposition was carried out using silicon having a purity of 99.9999% while introducing oxygen having a purity of 99.7% to form a SiO _0.5 layer having a film thickness of 20 μm on the surface of the convex portion 3 of the current collector 1. This was slitted to a predetermined width to produce a negative electrode plate.

(Example 2)

The negative electrode current collector 1 was configured in the same manner as in Example 1 except that the raised portions generated when the recesses 4a were formed on the peripheral surface of the roller 4 were used without being removed by polishing. Made. t ₁ is 17㎛, t ₂ was 21㎛. That is, t ₂ > t ₀ > t ₁ . When the cross section of the obtained negative electrode current collector 1 was observed in the same manner as in Example 1, occurrence of defects such as wavy wrinkles, warpage, and wrinkles was not recognized. The convex portion (3) the surface of the cathode body (1) houses in the same manner as in Example 1 to form a film layer having a thickness of _0.5 SiO 20㎛. This was slitted to a predetermined width to produce a negative electrode plate.

In the negative electrode current collectors 1 obtained in Examples 1 and 2, the convex portion 3 is formed by compressing the present invention on one surface of the copper foil. Such a negative electrode current collector 1 can efficiently deposit a negative electrode active material on the surface of the convex portion 3. In addition, it has sufficient durability against tensile stress applied to the longitudinal direction of the negative electrode current collector 1. For this reason, when the negative electrode active material is deposited on the negative electrode current collector 1, when the negative electrode active material is slit to a predetermined width after the deposition of the negative electrode active material, local deformation, distortion, or the like occurs in the negative electrode current collector 1. Is prevented. In addition, the dropping of the negative electrode active material layer can be suppressed.

(Example 3)

In the current collector manufacturing apparatus 35, except that the roller 5 is changed to the roller 4, it is the same as that of Example 1, and the convex parts 17x and 17y are formed on both surfaces of the base material part 16 in the thickness direction. The negative electrode collector 15 shown in FIG. 6 (c) was prepared. t ₃ is 16㎛, t ₄ was 25㎛. That is, t ₄ > t ₀ > t ₃ . When the cross section of the obtained negative electrode current collector 15 was subjected to a microscope in the same manner as in Example 1, occurrence of defects such as corrugated wrinkles, warpage, and wrinkles was not recognized. The convex portions (17x, 17y), the surface of the anode current collector (15), in the same manner as in Example 1 to form a film layer having a thickness of _0.5 SiO 20㎛. This was slitted to a predetermined width to produce a negative electrode plate.

(Example 4)

In the current collector manufacturing apparatus 35, except that the roller 5 is changed to the roller 4, it is similar to Example 2, and the convex parts 17x and 17y are formed on both surfaces of the base material part 16 in the thickness direction. The negative electrode collector 15 shown in FIG. 6 (c) was prepared. t ₃ is 16㎛, t ₄ was 25㎛. That is, t ₄ > t ₀ > t ₃ . When the cross section of the obtained negative electrode current collector 15 was subjected to a microscope in the same manner as in Example 1, occurrence of defects such as corrugated wrinkles, warpage, and wrinkles was not recognized. The convex portions (17x, 17y), the surface of the anode current collector (15), in the same manner as in Example 1 to form a film layer having a thickness of _0.5 SiO 20㎛. This was slitted to a predetermined width to produce a negative electrode plate.

In the negative electrode current collector 15 obtained in Examples 3 and 4, partial plastic deformation occurs due to compression processing of the present invention on both surfaces of copper foil, and convex portions 17x and 17y are formed. The negative electrode current collector 15 was able to efficiently deposit the negative electrode active material on the surfaces of the convex portions 17x and 17y. In addition, it has sufficient durability against tensile stress applied to the longitudinal direction of the negative electrode current collector 1. For this reason, when the negative electrode active material is deposited on the negative electrode current collector 1, when the slit has a predetermined width after the deposition of the negative electrode active material, and the like, local deformation, distortion, or the like occurs in the negative electrode current collector 1. Is prevented. In addition, the dropping of the negative electrode active material layer could be suppressed.

(Comparative Example 1)

The surface shape shown to Fig.20 (a) was processed to the peripheral surface of the cemented carbide roller of diameter 50mm with a peripheral surface flat. Except using this roller instead of the roller 4 in the electrical power collector manufacturing apparatus 35, it carried out similarly to Example 1, and processed the copper foil for electrical power collectors (18 micrometers in thickness). The cut surface of the copper foil after processing was observed with the scanning electron microscope. 19 is an electron micrograph of a cross section of the current collector 90 obtained in Comparative Example 1. FIG. It is clear from FIG. 19 that the wavy wrinkles generate | occur | produce in the electrical power collector of the comparative example 1. As shown in FIG. In the current collector manufacturing apparatus 35, the roller 5 was further used instead of the rubber roller to process the current collector copper foil, but the corrugated wrinkles could not be removed.

From the above results, it is clear that in the current collector obtained by the manufacturing method of the present invention, a plurality of convex portions are formed on the surface thereof by partial plastic deformation due to compression processing, and the convex portions exhibit sufficient durability. Therefore, in the process of forming a convex part on the metal foil surface, the process of supporting an electrode active material in the convex part of an electrical power collector, local deformation and a distortion of a current collector are prevented. Moreover, the fall of an electrode active material can also be suppressed also in the process of supporting an electrode active material in the convex part of an electrical power collector, the process of slitting a predetermined width, etc.

In addition, in the electrode obtained by the manufacturing method of the present invention, since the convex tip surface of the current collector is hardly affected by compression processing and plastic deformation, the processing tip does not remain on the convex tip surface, and the surface precision thereof is good. Do. Therefore, uniform thin film formation is possible. In addition, since the convex-tip surface does not reduce the surface roughness resulting from compression process, and maintains the initial surface roughness, it is thought that adhesive force with a thin film-like active material layer can be improved. From this point of view, in order to further increase the adhesion between the convex portion plane and the active material, it is considered very effective to make the surface of the current collector before processing even further rough.

(Example 5)

The rollers 4 and 5 in the current collector manufacturing apparatus 35 shown in Fig. 3 are ceramic rollers having a substantially circular shape and having a plurality of recesses 4a having a depth of 10 m and an opening diameter of 10 m. As fitted. A band-shaped aluminum foil having a thickness of 15 µm, which is the metal foil 10 for current collectors, is passed through the pressure welding nip portion 6 of the current collector manufacturing apparatus 35 under 10 kN pressure as a linear pressure to perform partial uncompression processing. The positive electrode current collector 70 shown in FIG. FIG. 14: is a figure which shows typically the structure of the electrical power collector 70 which is one of embodiment of this invention. 14A is a perspective view of the current collector 70. 14B is a longitudinal cross-sectional view of the current collector 70, that is, a cross-sectional view in the thickness direction.

The obtained current collector 70 is formed of a base portion 71 made of aluminum and a substantially circular convex portion 72x, 72y having a height of 4 µm regularly formed on both sides in the thickness direction of the base portion 71. And a convex portion 72 '}, and the base member 71 was a strip-shaped current collector having a thickness t ₃ of 12 µm and a maximum thickness t ₄ of 20 µm. In the widthwise direction (longitudinal direction) X, the row units 73 in which the convex portions 72 are arranged in a row at a pitch P ₁ are formed. In the short direction Y, the row units 73 are arranged in parallel at the pitch P ₂ . In addition, in the row unit 73 and the adjacent row unit 73, each convex part 72 is arrange | positioned so that it may shift by 0.5P ₁ minute in the width direction X. As shown in FIG. The arrangement pattern of the convex portions 72 is the closest charging arrangement.

Next, the aluminum foil having a length of 1000 mm and a thickness of 15 µm was used, and the pressing force in the pressure welding nip portion 6 was adjusted to change the volume ratio of the convex portion 72 as shown in Table 1 above. In the same manner as described above, convex portions 72 having different volume ratios with respect to the internal space volume of the concave portion 4a were formed, a current collector 70 was produced, and the surface state thereof was evaluated. Evaluation evaluated the generation | occurrence | production number of the wrinkles, the curvature, and the breakage visually about the 1000 electrical power collectors 70, and calculated | required. The results are shown in Table 1.

In addition, in Table 1, the volume ratio of a convex part is a percentage of the volume of the convex part 72 with respect to the internal space volume of the recessed part 4a. The same applies to the following.

TABLE 1

Volume percentage of convex part Crease Poor Incidence (%) Warp failure rate (%) Breakage failure rate (%) 55 0 0 0 65 0 0 0 75 0 0 0 81 0 0 0 83 0 0 0 85 0 0 0 87 3 5 0.8 89 7 14 3

When the current collector 70 is produced, tensile stress is applied to the longitudinal direction X of the current collector 70. If the current collector 70 is not durable against tensile stress, defects such as wrinkles, warpage, and breakage occur in the current collector 70. By the way, as is apparent from Table 1, when the volume ratio of the convex part 72 is 85% or less, the substantially circular convex part 72 is formed in the closest charging arrangement, and the collector 70 is long. It had sufficient durability against the tensile stress applied to the direction X, and generation | occurrence | production of the said defect was able to be suppressed. On the other hand, in the present embodiment, only the embodiment in which the volume ratio of the convex portion 72 is up to 55% is described, but when it is 55% or less, the pressing force is lowered. Production of the whole 70 was possible.

On the other hand, when the volume ratio of the convex part 72 was larger than 85%, the intensity | strength of the surface 71a of the base material part 71 might be insufficient, and defects, such as wrinkles, curvature, and a break | fever, generate | occur | produce locally.

In addition, when the surface roughness of the positive electrode current collector 70 whose volume ratio of the convex portion 72 was 85% or less was measured by a surface roughness machine, the surface roughness of the surface 71a of the base material portion 71 was determined before processing. It is becoming smaller than the surface roughness of aluminum foil. The surface roughness of the surface 71a of the base material portion 71 was almost equivalent to the surface roughness of the ceramic roller circumferential surface.

On the other hand, the surface roughness of the front end surface of the convex part 72 was almost equivalent to the surface roughness of the aluminum foil before a process. Moreover, when the front end surface of the convex part 72 was observed with the scanning electron microscope, the same fine scratches observed with the aluminum foil surface before a process were recognized.

Moreover, when the crystal orientation analysis was performed with the back-scattering electron diffraction image (EBSP) method about the electrical power collector 70, the inside of the surface 71a of the base material part 71, and the convex part 72 is aluminum before processing. It was observed that the crystal grains became finer than the foil. Moreover, when the tensile strength of the electrical power collector 70 was measured, although the thickness of the base material part 71 became thinner than the thickness of the aluminum foil before a process, the fall of tensile strength was not recognized. Since the base material part 71 is subjected to compression processing, it is guessed that the tensile strength improved by the work hardening by compression processing.

From the above analysis result, by performing the said process on aluminum foil, the compression process is not given to the part of the convex part 72, but the compression process is given to the surface 71a of the base material part 71, and a current collector It is thought that 70 is obtained.

(Example 6)

The shape of the opening is almost rhombus, and the ceramic roller which provided two or more recessed parts 4a of 10 micrometers in depth and 20 micrometers of opening diameters (the diagonal length of a diagonal shape) is shown by FIG. It mounted as the rollers 4 and 5 in the apparatus 35. As shown in FIG. A band-shaped copper foil having a thickness of 12 μm, which is the metal foil 10 for current collectors, is passed through the pressure welding nip portion 6 of the current collector manufacturing apparatus 35 under a linear pressure of 10 kN to perform partial uncompression processing. The illustrated current collector 75 for the positive electrode was produced. FIG. 15 is a diagram schematically showing a configuration of a current collector 75 which is one of embodiments of the present invention. 15A is a perspective view of the current collector 75. 15B is a longitudinal cross-sectional view of the current collector 75.

The obtained current collector 75 has a base portion 76 made of copper and a substantially rhombic convex portion 77x, 77y having a height of 4 占 퐉 formed regularly on both surfaces in the thickness direction of the base portion 76 {hereinafter, 'projections 77' to be contained}, and the substrate section 71 is the thickness t ₃ 10㎛, was the total of the belt-like house maximum thickness t ₄ of the 18㎛ a. In the width direction (long direction) X, the row units 78 in which the convex portions 77 are arranged in a row at a pitch P ₃ are formed. In the short direction Y, the row units 78 are arranged in parallel at the pitch P. As shown in FIG. And, it is a line-by-line 78, line unit 78, each of the convex portions 77 adjacent thereto are arranged to deviate by 0.5P ₃ minutes in the transverse direction X. The arrangement pattern of the convex portions 77 is the closest charging arrangement.

Next, except that the volume ratio of the convex part 77 is changed as shown in Table 2, using the copper foil of length 1000mm and thickness 12micrometer, and adjusting the pressing force in the pressure contact nip part 6, In the same manner as described above, convex portions 77 having different volume ratios with respect to the internal space volume of the concave portion 4a were formed, the current collector 75 was fabricated, and the surface state thereof was evaluated. Evaluation evaluated the generation | occurrence | production number of wrinkles, curvature, and the breakup visually about 1000 electrical power collectors 75, and calculated | required each occurrence rate. The results are shown in Table 2.

In addition, in Table 2, the volume ratio of a convex part is a percentage of the volume of the convex part 77 with respect to the internal space volume of the recessed part 4a. Hereinafter, the same will be done.

TABLE 2

Volume percentage of convex part Crease Poor Incidence (%) Warp failure rate (%) Breakage failure rate (%) 55 0 0 0 65 0 0 0 75 0 0 0 81 0 0 0 83 0 0 0 85 0 0 0 87 1.4 3 0.4 89 5 9 1.7

When the current collector 75 is produced, tensile stress is applied to the longitudinal direction X of the current collector 75. If the current collector 75 is not durable against tensile stress, defects such as wrinkles, warpage, and breakage occur in the current collector 75. By the way, as apparent from Table 1, when the volume ratio of the convex part 77 is 85% or less, the substantially circular convex part 77 is formed in the closest charging arrangement, and the collector 75 is long. It has sufficient durability with respect to the tensile stress applied to the direction X, and generation | occurrence | production of the said defect can be suppressed. On the other hand, in the present embodiment, only the embodiment in which the volume ratio of the convex portion 77 is up to 55% is described, but when it is 55% or less, the pressing force is lowered, so that the above-described defects are not generated. Production of the whole 75 was possible.

On the other hand, when the volume ratio of the convex part 77 is larger than 85%, the intensity | strength of the surface 76a of the base material part 76 will run short, and defects, such as wrinkles, curvature, and a break | break, locally generate | occur | produced.

In addition, when the surface roughness of the positive electrode current collector 75 in which the volume ratio of the convex portion 77 is 85% or less was measured by a surface roughness machine, the surface roughness of the surface 76a of the base material portion 76 was determined before processing. It is becoming smaller than the surface roughness of aluminum foil. The surface roughness of the surface 76a of the base material portion 76 was approximately equivalent to the surface roughness of the ceramic roller circumferential surface.

On the other hand, the surface roughness of the front end surface of the convex part 77 was almost equivalent to the surface roughness of the aluminum foil before processing. In addition, when the front surface of the convex part 77 was observed with the scanning electron microscope, the fine scratches recognized by the aluminum foil surface before processing were recognized.

Moreover, when the crystal orientation analysis was performed by the back-scattering electron diffraction image (EBSP) method with respect to the electrical power collector 75, the inside of the surface 76a of the base part 76, and the convex part 77 is aluminum before processing. It was observed that the crystal grains became finer than the foil. Moreover, when the tensile strength of the collector 75 was measured, although the thickness of the base material part 76 became thinner than the thickness of the aluminum foil before a process, the fall of tensile strength was not recognized. Since the base material portion 76 is subjected to compression processing, it is assumed that the tensile strength is improved by work hardening by compression processing.

From the above analysis results, by performing the above processing on the aluminum foil, compression processing is not performed on the portion of the convex portion 77, but compression processing is performed on the surface 76a of the substrate portion 76, and the current collector It is thought that (75) is obtained.

(Example 7)

Instead of the copper foil having a thickness of 12 µm, a copper foil having a thickness of 18 µm was used, except that Example 6 and the pressing force at the pressure welding nip portion 6 were adjusted so that the volume ratio of the convex portion 77 was 80%. In the same manner, a strip-shaped current collector 75 was produced. The current collector 75 has a sufficient durability against the tensile stress applied to the long direction X because the rhombic convex portions 77 are arranged in the closest filling shape. For this reason, when processing the current collector 75, it is possible to prevent the local deformation and distortion of the current collector 75 from occurring, and furthermore, the active material is peeled off from the current collector 75 and dropped off. It can be suppressed. The processing of the current collector 75 refers to the supporting of the active material on the surface of the current collector 75, and the slit processing of the electrode obtained by supporting the active material on the current collector 75 surface.

The current collector 75 obtained above was mounted inside the vacuum deposition apparatus provided with the electron beam heating means. As a target, vapor deposition was carried out using silicon having a purity of 99.9999% while introducing oxygen having a purity of 99.7% to form a columnar SiO _0.5 layer having a film thickness of 25 μm on the surface of the convex portion 77 of the current collector 75. did. This was slit-processed to predetermined width in the cylindrical nonaqueous electrolyte secondary battery, and the negative electrode plate was produced. On the other hand, in the current collector 75, since the substantially rhombic convex portions 77 are arranged in the closest filling shape, when the negative electrode active material is deposited in the short direction Y, the convex portions 77 can be efficiently attached to the surface. Could.

According to the manufacturing method of this invention of Examples 5-7, by using the ceramic roller in which the several recessed part was formed in the circumferential surface, partial plastic deformation is produced on the surface of the metal foil for electrical power collectors, and a convex part is formed. Moreover, by making the volume of a convex part below the internal space volume of a concave part, the nonuniformity, such as a shape, a size, etc. of a convex part is eliminated. As a result, the mechanical strength and durability of the obtained current collector can be improved. In addition, the durability of the current collector is further improved by selecting the arrangement pattern of the convex portions. Accordingly, in the process of forming a convex portion on the surface of the metal foil for current collector to produce a current collector, and the process of preparing an electrode by supporting an active material on the surface of the current collector, deformation, skew, etc. occur locally in the current collector. Can be prevented. Further, the active material can be prevented from peeling off from the current collector in a step of preparing an electrode by supporting the active material on the surface of the current collector, a step of slitting the electrode to a predetermined width, and the like.

In addition, according to the manufacturing method of the present invention, since the convex portion of the current collector is formed by plastic deformation due to compression processing, and the distal end surface of the convex portion is hardly affected by plastic deformation, the distorted portion of the convex portion is hardly processed. It is not happening. Therefore, the surface precision of the front end surface of a convex part is favorable, and it becomes possible to form a uniform thin film active material layer on the front end surface. In addition, since the front end surface of a convex part is not subjected to compression processing, surface roughness does not become small and maintains the surface roughness of the metal foil for electrical power collectors. Therefore, it is thought that adhesive force with an active material layer becomes higher. From this point of view, in order to further increase the adhesion between the plane of the convex portion and the electrode active material, it is considered very effective to make the surface of the current collector before processing into a rough state in advance.

(Example 8)

The roller 28 shown in FIG. 9 was produced as follows. Laser processing using a YAG laser was formed on the circumferential surface of a superhard metal recessed forming roller having a diameter of 50 mm to form a recess having a substantially circular shape having a diameter of about 10 µm and a depth of about 8 µm. The laser frequency of laser processing is 1KHz.

At the edges of the openings of the recesses formed above, burrs and bulges formed were formed, and the surface roughness of the rollers was partially increased. For this reason, grinding | polishing was performed by the grinding | polishing machine provided with a polishing pad, supplying water using the diamond particle of average micrometer diameter of 8 micrometers as an abrasive grain. Polishing was performed until the average surface roughness of the roller peripheral surface became 0.4a. As a result, the ridges were removed to form the concave portion 29 having the edge 29a of the opening having a curved surface, thereby producing the roller 28.

The surface roughness of the roller 28 is about the same as the surface roughness of the metal foil which is a raw material. Therefore, in the current collector obtained after the compression processing, the front surface of the convex portion maintains the surface roughness of the original metal foil, and the surface of the substrate portion is subjected to the compression processing by the roller 28, which is almost the same as the surface roughness of the roller 28. Has surface roughness That is, the entire surface of the surface of the current collector has almost the same surface roughness. By using such an electrical power collector, the adhesiveness of an electrical power collector and an active material layer can be improved further.

On the other hand, if the metal foil is subjected to compression processing using a roller which is not subjected to polishing, stress concentrates on the ridges of the opening edges of the concave portion, and it becomes a starting point of cracks on the roller circumferential surface, and the roller life may be reduced. There is.

(Example 9)

The roller 28 was produced like Example 8 except having used the diamond particle of an average particle diameter of 30 micrometers instead of the diamond particle of an average particle diameter of 8 micrometers.

(Example 10)

The roller 28 was produced like Example 8 except having used the diamond particle of an average particle diameter of 53 micrometers instead of the diamond particle of an average particle diameter of 8 micrometers.

(Example 11)

The roller 28 was produced like Example 8 except having used the diamond particle of an average particle diameter of 74 micrometers instead of the diamond particle of an average particle diameter of 8 micrometers. On the other hand, at this time, the average surface roughness of the roller 28 could not be made smaller than 0.8a.

Regarding the rollers 28 obtained in Examples 8 to 11, the residual state of abrasive particles (diamond particles) on the roller 28 circumferential surface after diamond polishing, the average surface roughness of the roller 28 circumferential surface, and the current collector production The damage state of the subsequent roller 28 circumferential surface was determined. In addition, the residual state and the broken state were determined by electron microscope observation. The results are shown in Table 3.

TABLE 3

Average Particle Diameter of Abrasive Particles (㎛) After diamond polishing Residual state of abrasive particles Average surface roughness of the roller perimeter Damage state of roller circumference Example 8 8 has exist 0.4a none Example 9 30 none 0.4a none Example 10 53 none 0.4a none Example 11 74 none 0.8a has exist

From Table 3, when polishing is performed using diamond particles having an average particle diameter of 8 µm, the ridges of the opening edge 29a of the recess 29 are removed, and the opening edge 29a is curved, but the recess 29 It is evident that the diamond particles remained at). The diamond particles remaining in the recess 29 could not be completely removed even by ultrasonic cleaning. If the current collector is produced with diamond particles remaining in the concave portion 29, the formation of the convex portion may be insufficient.

In addition, when diamond particles having an average particle diameter of 74 µm were used, an average surface roughness of the peripheral surface of the roller 28 remained at a finish up to an average roughness of 0.8 µm, and it was recognized that the portion where the bulge was not removed. In addition, when diamond particles having an average particle diameter of 30 µm and 53 µm are used, the opening edge 29a of the recess 29 is curved, there is no residual of diamond particles, and the average surface roughness of the peripheral surface is 0.4a or The following roller 28 was obtained.

In addition, with respect to the roller 28 of Example 9 and Example 10, a polishing pad is supplied to the opening edge 29a of the recessed part 29 using diamond grain of 5 micrometers of average particle diameters as an abrasive, Polishing was carried out with a polishing machine equipped with a groove to form a groove 29x having a width of about 1 μm and a depth of about 1 μm. Diamond particles having an average particle diameter of 5 µm are the smallest particles in commercially available products that can control the variation in particle size distribution.

By forming such a groove 29x, air or the like remaining in the recess at the time of forming the convex portion is smoothly discharged to the outside of the recess. As a result, the air remaining inside the concave portion is compressed, and the smooth plastic deformation of the convex portion is inhibited by the pressure, and the shape, height, and the like of the convex portion are prevented from being uneven.

On the other hand, in the current collector, the height from the surface of the base portion of the convex portion is determined in consideration of the life of the roller 28 and the like, in addition to the characteristics of the electrode to be finally obtained. In order to increase the useful life of the roller 28, it is preferable to make the pressing force in a pressure welding nip part small. Therefore, it is preferable to adjust so that a pressing force may be made small and the convex part of a required height is formed.

The roller 28 with the grooves 29y formed therein was subjected to compression processing with a length of 80 mm in the direction perpendicular to the conveyance direction of the copper foil having a thickness of 26 µm and a pressing force of 80 kN in the pressure welding nip portion, thereby performing partial plastic deformation. When it generate | occur | produced, the convex part whose height from the surface of a base material part is an average of 5.1 micrometers was formed.

On the other hand, except that the rollers 28 of Examples 9 and 10 in which the grooves 29y were not formed were used in the same manner as described above, the copper foil was subjected to compression processing. Phosphorus was formed. When a solid lubricant or a liquid lubricant is used for releasability, wear, and lubrication, the height of the convex portion becomes larger, and the shape becomes uniform.

(Example 12)

The recessed part 29 was formed in the circumferential surface of the ceramic recessed part formation roller of diameter 25mm similarly to Example 9, and the roller 28 was produced. This roller 28 was mounted as the roller 4 in the electrical power collector manufacturing apparatus 35 shown in FIG. 3, and the pressure welding nip part 34 was formed. A copper foil having a width of 18 mm and a width of 80 mm and a length of 100 m in a direction perpendicular to the conveying direction is supplied to the pressure welding nip portion 34 and subjected to compression processing under pressure of 80 kN to generate partial plastic deformation, and FIG. 8 The current collector 20 shown in FIG.

(Example 13)

The current collector 20 was produced in the same manner as in Example 12 except that the roller diameter of the concave forming roller was changed to 50 mm.

(Example 14)

The current collector 20 was produced in the same manner as in Example 12 except that the roller diameter of the concave forming roller was changed to 100 mm.

(Example 15)

A current collector 20 was produced in the same manner as in Example 12 except that the roller diameter of the concave forming roller was changed to 150 mm.

For the current collectors 20 obtained in Examples 12 to 15, the difference between the average height of the convex portions 22 and the maximum and minimum values of the convex portions 22 was determined by electron microscope observation. The convex part average height is an average value of 100 convex parts 22. As shown in FIG. About the roller 28 after the collector 20 was produced, the damage state of the recessed part 29 was visually observed further. Meanwhile, The height of the convex part 20 is the length from the surface 21a to the front end surface of the convex part 20 in the direction perpendicular | vertical to the surface 21a of the base material part 21 in the sectional drawing shown in FIG. The results are shown in Table 4.

TABLE 4

Roller diameter (mm) Convex part average diameter (㎛) Difference between the maximum value and the minimum value of the convex height (µm) Damage state of recess of roller Example 12 25 8.0 4.2 has exist Example 13 50 7.4 1.8 has exist Example 14 100 4.1 1.1 none Example 15 150 2.1 1.2 none

As is apparent from Table 2, at a roller diameter of 25 mm, the average height of the convex portions 22 was 8 m. However, relatively large distortion also occurred in the roller 28 itself, and the deviation of the height of the convex portion 22 was large. In addition, there was an irregularity in the rotation of the roller 28, and it was estimated that continuous processing was difficult.

Although the average height of the convex part 22 was 7.4 micrometers in roller diameter 50mm, the skew of the roller 28 was recognized notably, and the deviation of the height of the convex part 22 was about +/- 1 micrometer. Moreover, when the recessed part 29 of the roller 28 was observed after preparation of the electrical power collector 20, many cracks generate | occur | produce. From these, it is guessed that roller diameter has a big influence on the lifetime of the roller 28. As shown in FIG.

At a roller diameter of 100 mm, the average height of the convex portions 22 was 4.1 μm, and the variation in the height of the convex portions 22 was ± 1 μm or less. Moreover, when the recessed part 29 of the roller 28 was observed after preparation of the collector 20, a crack was not recognized. Although 500 m and 1000 m were further produced for the electrical power collector 20, the crack was not recognized in the recessed part 29 again.

At a roller diameter of 150 mm, the average height of the convex portions 22 was 2.1 μm, and the variation in the height of the convex portions 22 was ± 1 μm or less. When the recessed part 29 of the roller 28 was observed after preparation of the collector 20, a crack was not recognized. Although the current collector 20 was further fabricated 1000m, cracks were not recognized in the oh neck 29, too. However, in order to obtain the convex part 22 which has a sufficient height, it was found that the pressing force needs to be made very large, and in order to do so, the size of equipment was required to be enlarged.

Based on the result shown in Table 3 and Table 4, it turned out that the roller 28 produced in Example 14 can be used preferably. For the production of the roller 28, diamond particles having an average particle diameter of 30 µm are used in the polishing step, grooves 29x are formed in the opening edge 29a of the recess 29, and the average surface roughness of the roller circumferential surface is formed. Was 0.4a, and the roll diameter was 100 mm.

In the current collector 20 produced in Examples 11 to 14, the boundary portion 22a between the base portion 21 and the convex portion 22 is formed of a curved surface, and the convex portion 22 shown in FIG. ) Has a tapered shape. As a result, workability at the time of compression processing and releasability from the roller 28 of the current collector 20 are improved, and the convex portion 22 is strongly fitted to the concave portion 29 of the roller 28, whereby the current collector Peeling from (20) can be prevented.

When the electrode group is composed of a positive electrode plate carrying a positive electrode active material on the current collector 20 having a large number of convex portions 22 that are easily peeled off, the current collector 20 starts to cause wrinkles of the positive electrode plate in the process of repeating charge and discharge. It turns out that a positive electrode active material peels. This is considered to be caused by the nonuniformity of the mechanical strength of the collector 20.

Thus, by processing using a pair of rollers, pressurization at a very small contact area becomes possible, and the pressing force can be increased. As a result, the current collector manufacturing apparatus 35 can be miniaturized.

(Example 16)

A roller 28A having the same configuration as the roller 28 shown in FIG. 9 was produced as follows except that the opening shape of the recessed part 29 was almost a rhombus. On the circumferential surface of the cemented carbide roller having a diameter of 50 mm, laser processing using a YAG laser shows that the opening shape is almost rhombic, and the diagonal of the longer rhombus is 20 µm in length and approximately 10 µm in depth. A recess was formed. Laser processing performed the laser frequency as 1 kHz.

At the edge of the opening of the recess formed above, a ridge formed by burring or swelling was formed, and the surface roughness of the roller was partially increased. In particular, when the opening shape of the concave portion is a rhombus, directionality occurs in the burr or swelling, and the surface shape deteriorates as a whole. For this reason, grinding | polishing was performed by the grinding | polishing machine provided with a polishing pad, supplying water using the diamond particle of average micrometer diameter of 8 micrometers as an abrasive grain. Polishing was performed until the average surface roughness of the roller peripheral surface became 0.4a. As a result, the ridges were removed to form the concave portion 29 in which the edge 29a of the opening was formed into a curved surface, thereby producing a roller 28A.

The surface roughness of the roller 28A is about the same as the surface roughness of the metal foil which is a raw material. Therefore, in the current collector obtained after compression processing, the front surface of the convex portion maintains the surface roughness of the original metal foil, and the surface of the substrate portion is subjected to compression processing by the roller 28A, which is almost the same as the surface roughness of the roller 28A. Has surface roughness That is, the entire surface of the surface of the current collector has almost the same surface roughness. By using such an electrical power collector, the adhesiveness of an electrical power collector and an active material layer can be improved further.

On the other hand, when the metal foil is subjected to the compression processing of the present invention using a roller which has not been subjected to polishing, stress concentrates on the raised portions of the opening edges of the concave portion, which becomes the starting point of the cracks on the roller circumferential surface, and thus the roller life. There is a risk of deterioration. In particular, when the opening shape is almost rhombic, the two acute angles are susceptible to stress concentration because of its shape, and become the starting point of the crack in the peripheral surface of the roller 28A, and propagation of the crack between the adjacent recesses 29. Since it also became a path | route, it turned out that the roller life is greatly reduced.

(Example 17)

A roller 28A was produced in the same manner as in Example 16 except that diamond particles having an average particle diameter of 30 µm were used instead of diamond particles having an average particle diameter of 8 µm.

(Example 18)

A roller 28A was produced in the same manner as in Example 16 except that diamond particles having an average particle diameter of 53 μm were used instead of diamond particles having an average particle diameter of 8 μm.

(Example 19)

A roller 28A was produced in the same manner as in Example 16 except that diamond particles having an average particle diameter of 74 µm were used instead of diamond particles having an average particle diameter of 8 µm. On the other hand, at this time, the average surface roughness of the roller 28A could not be made smaller than 0.8a.

Regarding the roller 28A obtained in Examples 16 to 19, the residual state of abrasive particles (diamond particles) on the peripheral surface of the roller 28A after diamond polishing, the average surface roughness of the peripheral surface of the roller 28A, and the current collector production The damage state of the subsequent roller 28A circumferential surface was determined. In addition, the residual state and the broken state were determined by electron microscope observation. The results are shown in Table 5.

TABLE 5

Average Particle Diameter of Abrasive Particles (㎛) After polishing Damage to the roller recess Residual state of abrasive particles Average surface roughness of the roller perimeter Example 16 8 has exist 0.4a none Example 17 30 none 0.4a none Example 18 53 none 0.4a none Example 19 74 none 0.8a has exist

From Table 5, when polishing is performed using diamond particles having an average particle diameter of 8 µm, the ridges of the opening edge 29a of the recess 29 are removed, and the opening edge 29a is curved, but the recess 29 It is evident that the diamond particles remained at). Diamond particles remaining in the recess 29 could not be completely removed even by ultrasonic cleaning. In addition, when the current collector was produced with diamond particles remaining in the concave portion 29, the formation of the convex portion was insufficient.

In addition, when diamond particles having an average particle diameter of 74 µm were used, the average surface roughness of the peripheral surface of the roller 28A remained at the finish up to an average roughness of 0.8 µm, and it was recognized that the portion where the bulge was not removed. In addition, when diamond particles having an average particle diameter of 30 µm and 53 µm are used, the opening edge 29a of the concave portion 29 is curved, there is no residual of diamond grains, and the average surface roughness of the circumferential surface is 0.4a. Or less roller 28A was obtained.

In addition, with respect to the roller 28A of Examples 17 and 18, the polishing pad was supplied to the opening edge 29a of the recess 29 using water as diamond abrasive particles having an average particle diameter of 5 탆 as water. Polishing was carried out using a polisher provided to form grooves 29x having a width of about 1 μm and a depth of about 1 μm. Diamond particles having an average particle diameter of 5 µm are the smallest particles in the commercially available product which can control the variation in particle size distribution.

By forming such a groove 29x, air or the like remaining in the recess at the time of forming the convex portion is smoothly discharged to the outside of the recess. As a result, the air remaining inside the concave portion is compressed, and the smooth plastic deformation of the convex portion is inhibited by the pressure, and the shape, height, and the like of the convex portion are prevented from being uneven.

On the other hand, in the current collector, the height from the surface of the base portion of the convex portion is determined in consideration of the life of the roller 28A, etc., in addition to the characteristics of the electrode to be finally obtained. In order to increase the service life of the roller 28A, it is preferable to reduce the pressing force in the pressure welding nip portion. Therefore, it is preferable to adjust so that a pressing force may be made small and the convex part of a required height is formed. In particular, in the case where the opening shape is almost rhombic, a higher pressing force is required than in the case where the opening shape is almost circular in order to obtain a sufficient height. Moreover, it turns out that about 15%-23% height becomes low even if it presses on substantially the same conditions to the substantially circular shape which projected from the plane. This is presumed to be due to the resistance caused by the variation in the thickness in the long-axis cross section of the rhombus because the cross-sectional shape is narrow.

Compression processing is performed by using a roller 28A having grooves 29y formed therein, the length of the direction perpendicular to the conveying direction of the copper foil having a thickness of 18 µm being 80 mm, and the pressing force at the pressure welding nip portion being 80 kN. When a deformation | transformation was produced, the convex part whose height from the surface of a base material part is an average of 7.1 micrometers was formed.

On the other hand, except for using the roller 28A in which the groove 29y was not formed, the compression process was performed as above, and the convex part whose average height from the surface of a base material part is 5.5 micrometers was formed. When a solid lubricant or a liquid lubricant is used for releasability, wear, and lubrication, the height of the convex portion becomes larger, and the shape becomes uniform.

(Example 20)

The recessed part 29 was formed in the circumferential surface of the ceramic recessed part formation roller of diameter 25mm similarly to Example 17, and roller 28A was produced. This roller 28A was mounted as the rollers 4 and 5 in the current collector manufacturing apparatus 35 shown in FIG. 3, and the pressure welding nip 34a was formed. A copper foil having a width of 26 μm and a width of 80 mm and a length of 100 m in a direction perpendicular to the conveying direction is supplied to the pressure-contacting nip portion 34a, and subjected to compression processing under a pressure of 80 kN to partially generate plastic deformation, and FIG. 10. The current collector 23 shown in Fig. 2 was produced.

(Example 21)

A current collector 23 was produced in the same manner as in Example 20 except that the roller diameter of the concave forming roller was changed to 50 mm.

(Example 22)

A current collector 23 was produced in the same manner as in Example 20 except that the roller diameter of the concave forming roller was changed to 100 mm.

(Example 23)

A current collector 23 was produced in the same manner as in Example 20 except that the roller diameter of the concave forming roller was changed to 150 mm.

For the current collectors 23 obtained in Examples 20 to 23, the difference between the average height of the convex portions 25x and 25y (hereinafter referred to as the 'convex portion 25') and the maximum value and the minimum value of the convex portion 25 is shown. It calculated | required by electron microscope observation. The convex part average height is an average value of 100 convex parts 25. As shown in FIG. Moreover, the damage state of the recessed part 29 was visually observed about the roller 28A after the collector 23 preparation. On the other hand, the height of the convex part 25 is from the surface 24a to the front end surface of the convex part 25 in the direction perpendicular | vertical to the surface 24a of the base material part 24 in the sectional drawing shown in FIG. Length. The results are shown in Table 6.

TABLE 6

Diameter of roller (mm) Average convex height (μm) Difference between the maximum value and the minimum value of the convex height (µm) Damage state of recess of roller Example 20 25 10.0 5.6 has exist Example 21 50 8.2 2.1 has exist Example 22 100 7.1 1.7 none Example 23 150 4.3 1.6 none

As is apparent from Table 6, at a roller diameter of 25 mm, the average height of the convex portions 25 was 10 m. However, relatively large distortion also occurred in the roller 28A itself, and the deviation of the height of the convex portion 25 was large. In addition, there was an irregularity in the rotation of the roller 28A, and it was estimated that continuous processing was difficult.

Although the average height of the convex part 25 was 8.2 micrometers at the roller diameter of 50 mm, the skew of the roller 28A was recognized little, and the deviation of the height of the convex part 25 was about +/- 1 micrometer. Moreover, when the recessed part 29 of the roller 28A was observed after preparation of the collector 23, many cracks generate | occur | produce. From these, it is guessed that roller diameter has a big influence on the lifetime of the roller 28. As shown in FIG.

At a roller diameter of 100 mm, the average height of the convex portions 25 was 7.1 μm, and the variation in the height of the convex portions 25 was ± 1 μm or less. In addition, when the recessed part 29 of the roller 28A was observed after preparation of the collector 23, a crack was not recognized. In addition, although 500 m and 1000 m were produced for the electrical power collector 23, the crack was not recognized in the recessed part 29 again.

At a roller diameter of 150 mm, the average height of the convex portions 25 was 4.3 μm, and the variation in the height of the convex portions 25 was ± 1 μm or less. When the recessed part 29 of the roller 28A was observed after preparation of the collector 23, a crack was not recognized. Although the current collector 23 was further manufactured 1000m, no crack was recognized in the recessed part 29 again. However, in order to obtain the convex part 25 which has sufficient height, it was understood that the pressing force needs to be made very large, and in order to do so, the installation size needs to be enlarged.

Based on the result shown in Table 5 and Table 6, it turned out that the roller 28A manufactured in Example 22 can be used preferably. In the production of the roller 28A, in the polishing step, diamond particles having an average particle diameter of 30 µm are used, grooves 29x are formed in the opening 29a of the recess 29, and the average of the roller circumferential surface is formed. The surface roughness was 0.4a, and the roll diameter was 100 mm.

In the current collector 23 produced in Examples 20 to 23, the boundary portion 25a between the base portion 24 and the convex portion 25 is formed of a curved surface, and the convex portion 25 shown in FIG. Has a tapered shape. Thereby, workability at the time of compression processing and releasability from the roller 28A of the collector 23 are improved, and the convex part 25 is firmly fitted to the recessed part 29 of the roller 28A, and the collector Peeling from (23) was prevented.

When the electrode group is formed of a negative electrode plate on which a negative electrode active material is carried on a current collector 23 having a large number of convex portions 25 that are easily peeled off, the current collector 23 is a starting point of wrinkle generation of the negative electrode plate in a process of repeating charge and discharge. It turns out that a negative electrode active material peels. This is considered to be caused by the nonuniformity of the mechanical strength of the collector 23.

Thus, by processing using a pair of rollers, pressurization at a very small contact area becomes possible, and the pressing force can be increased. As a result, the current collector manufacturing apparatus 35 can be miniaturized.

(Example 24)

The current collector manufacturing apparatus 35 shown in FIG. 3 shows the ceramic roller 28 shown in FIG. 9 in which the opening has a substantially circular shape, and a plurality of recesses 29 having a depth of 8 µm and an opening diameter of 10 µm are formed. It mounted as the rollers 4 and 5 in the present invention. A band-shaped aluminum foil having a thickness of 15 µm, which is the metal foil 10 for current collectors, is passed through a pressure-contacting nip portion 34A (FIG. 11) of the current collector manufacturing apparatus 35 under pressure of 10 kN and subjected to partial uncompression processing. The positive electrode current collector 80 shown in Fig. 16 was produced. FIG. 16: is a figure which shows typically the structure of the electrical power collector 80 which is one of embodiment of this invention. 16A is a perspective view of the current collector 80. 16B is a longitudinal cross-sectional view of the current collector 80.

The obtained current collector 80 is formed of a base portion 81 made of aluminum and a substantially circular convex portion 82x, 82y having a height of 5 µm regularly formed on both surfaces in the thickness direction of the base portion 81 (hereinafter ' And the convex portion 82 '}, and the base member 81 was a strip-shaped current collector having a thickness t ₇ of 12 µm and a maximum thickness t ₈ of 20 µm. In the width direction (long direction) X, the row units 83 in which the convex portions 82 are arranged in a row at a pitch P ₅ are formed. In the transverse direction Y, there is a line-by-line 83 is arranged parallel to the pitch P _6. In addition, the row unit 83 and the row unit 83 adjacent thereto are arranged such that each convex portion 82 is shifted by 0.5P ₅ minutes in the width direction X. The arrangement pattern of the convex portions 82 is the closest charging arrangement.

In the current collector 80, the boundary portion 82a of the base portion 81 and the convex portion 82 is formed of a curved surface. Thereby, workability at the time of compression processing and the release property from the roller 28 of the collector 80 are improved. In addition, since the substantially circular convex portions 82 are arranged closest to each other, the current collector 80 has sufficient durability against tensile stress applied to the long direction X. For this reason, it can prevent that deformation | transformation and the distortion locally generate | occur | produce in the collector 80 at the time of manufacture of the collector 80, the process of the collector 80, etc.

Moreover, when the surface roughness of the electrical power collector 80 was measured by the surface roughness machine, the surface 81a of the base material part 81 is smaller in surface roughness than the aluminum foil before processing. The surface roughness of the surface 81a of the base material portion 81 was almost the same as the surface roughness of the ceramic roller 28.

On the other hand, the surface roughness of the front end surface of the convex part 82 was substantially the same as the aluminum foil before processing. Moreover, when the front surface of the convex part 82 was observed with the scanning electron microscope, the same fine scratches observed with the aluminum foil before processing were recognized.

Moreover, when the crystal orientation analysis was performed with the back-scattered electron diffraction image (EBSP) method with respect to the electrical power collector 80, the inside of the surface 81a of the base part 81 and the convex part 82 is aluminum before processing. It can be seen that the crystal grains are finer than the foil. Moreover, as a result of measuring the tensile strength of the electrical power collector 80, although the thickness of the base part 81 becomes thinner than the aluminum foil before a process, the fall of tensile strength is not recognized and it is not recognized for the work hardening by compression processing. It is estimated that the tensile strength improved by this.

From the above analysis results, by performing the above processing on the aluminum foil, compression processing is not performed on the portion of the convex portion 82, but compression processing is performed on the surface 81a of the base portion 81, and the current collector It is thought that (80) is obtained.

The positive electrode mixture slurry was applied to both surfaces of the current collector 80 obtained above, dried, and pressed so as to have a total thickness of 126 μm, thereby producing a positive electrode having a thickness of 58 μm on one side of the positive electrode active material layer. This was slitted to a predetermined width to produce a positive electrode plate.

The positive electrode mixture slurry is 100 parts by weight of lithium cobalt oxide in which a part of cobalt is substituted with nickel and manganese, 2 parts by weight of acetylene black (conductive material), 2 parts by weight of polyvinylidene fluoride (binder) and an appropriate amount of N-. Methyl-2-pyrrolidone was prepared by stirring and kneading with a double linker.

In the current collector 80, as shown in Fig. 16, almost circular convex portions 82 are arranged closest to each other, and the boundary portion 82a between the substrate portion 81 and the convex portions 82 is formed of a curved surface. Therefore, it has sufficient durability against the tensile stress applied to the long direction X. Therefore, in the process of applying the positive electrode mixture slurry to the current collector 80, drying and pressing to form the positive electrode, and the process of slitting the positive electrode to a predetermined width, deformation or distortion local to the current collector 80 occurs. It can prevent that, and the fall of a positive electrode active material layer can be suppressed.

(Example 25)

Fig. 3 shows the ceramic roller 28A shown in Fig. 9 in which the shape of the opening is almost rhombic, and a plurality of concave portions 29 having a depth of 10 m and a longer diagonal of 20 m are formed. It mounted as the rollers 4 and 5 in the whole manufacturing apparatus 35. The 12-micrometer-thick strip | belt-shaped copper foil which is the metal foil 10 for electrical power collectors is made to pass through the pressure welding nip part 34A (FIG. 11) of the electrical power collector manufacturing apparatus 35 under pressure of 10 kN, and it compresses partially. Plastic deformation was produced to produce a negative electrode current collector 85 shown in FIG. 17. 17 is a diagram schematically showing a configuration of a current collector 85 which is one of embodiments of the present invention. 17A is a perspective view of the current collector 85. 17B is a longitudinal cross-sectional view of the current collector 85.

The obtained current collector 85 is formed of a base portion 86 made of copper and a substantially rhombic convex portion 87x, 87y having a height of 6 µm regularly formed on both surfaces in the thickness direction of the base portion 86 { and "convex portion 87 La is contained}, and the substrate section 86, the thickness t is 6㎛ _9, was a total of the maximum thickness of the strip-shaped house ₁₀ is t 18㎛ of the. In the width direction (long direction) X, the row units 88 in which the convex portions 86 are arranged in a row at a pitch P ₇ are formed. In the transverse direction Y, there is a line-by-line (88) are arranged in parallel at a pitch P _8. In addition, the row unit 88 and the row unit 88 adjacent thereto are arranged so that each convex portion 87 is shifted by 0.5P ₇ minutes in the width direction X. The arrangement pattern of the convex portions 87 is the closest charging arrangement.

In the current collector 85, the boundary portion 86a of the base portion 86 and the convex portion 87 is formed of a curved surface. Thereby, workability at the time of compression processing and the release property from the roller 28 of the collector 85 are improved. In addition, since the convex portions 87 of the rhombic shape are arranged closest to each other, the current collector 85 has sufficient durability against the tensile stress applied in the long direction X. For this reason, deformation | transformation and the distortion in the collector 85 can be prevented locally at the time of manufacture of the collector 85, the process of the collector 85, etc.

Moreover, when the surface roughness of the electrical power collector 85 was measured by the surface roughness machine, the surface roughness of the base material 86 is smaller than the copper foil before a process. The surface roughness of the surface 86a of the base material portion 86 was almost the same as the surface roughness of the ceramic roller 28.

On the other hand, the surface roughness of the front end surface of the convex part 87 was substantially the same as copper foil before a process. Moreover, when the front end surface of the convex part 87 was observed with the scanning electron microscope, the same fine scratches observed with the copper foil before processing were recognized.

In addition, when the crystal orientation analysis was performed by the backscattered electron diffraction image (EBSP) method with respect to the electrical power collector 85, the inside of the surface 86a and the convex part 87 of the base part 86 is a copper before processing. It can be seen that the crystal grains are finer than the foil. Moreover, as a result of measuring the tensile strength of the collector 85, although the thickness of the base material part 86 became thinner than the copper foil before a process, the fall of tensile strength is not recognized, and it is not recognized for the work hardening by compression processing. It is estimated that the tensile strength improved by this.

From the above analysis result, by performing the said process to copper foil, the plastic deformation by compression process arises in the part of the convex part 87, and the compression process is given to the surface 86a of the base material part 86, The current collector 85 is considered to be obtained.

The current collector 85 obtained above was mounted inside the vacuum vapor deposition apparatus provided with the electron beam heating means. As a target, vapor deposition was carried out using silicon having a purity of 99.9999% and introducing oxygen having a purity of 99.7% to form a SiO _0.5 layer having a film thickness of 20 μm on the surfaces of the convex portions 87 on both sides of the current collector 85 in a columnar shape. did. This was slitted to a predetermined width to produce a negative electrode plate.

In the current collector 85, as shown in Fig. 17A, the convex portions 87 having substantially rhombic shapes are formed in the closest filling arrangement on both surfaces thereof, and the base portion 86 and the convex portions 87 are formed. The boundary portion 87a is formed of a curved surface. For this reason, when depositing a negative electrode active material toward the longitudinal direction X of the electrical power collector 85, it can adhere to the surface of the convex part 87 efficiently.

Moreover, it has sufficient durability against the tensile stress applied to the longitudinal direction X of the collector 85. For this reason, the current collector 85 may be used in a process of producing a strip-shaped current collector 85, a process of depositing a negative electrode active material on the surface of the current collector 85, a process of manufacturing a negative electrode plate, and a process of slitting the negative electrode plate to a predetermined width. The occurrence of local deformations and skews is prevented. At the same time, the dropping of the negative electrode active material can be suppressed.

(Example 26)

The current collector manufacturing apparatus 35 shown in FIG. 3 shows the ceramic roller 28 shown in FIG. 9 in which the opening has a substantially circular shape, and a plurality of recesses 29 having a depth of 10 µm and an opening diameter of 10 µm are formed. It mounted as the rollers 4 and 5 in the present invention. The 18-micrometer-thick strip | belt-shaped copper foil which is the metal foil 10 for electrical power collectors is made to pass through the pressure welding nip part 34A (FIG. 11) of the electrical power collector manufacturing apparatus 35 under pressure of 10 kN, and it compresses partially. Plastic deformation was caused to produce a negative electrode current collector 80 shown in FIG. 16.

The obtained current collector 80 has a base portion 81 made of copper and a substantially circular convex portion 82x, 82y having a height of 8 占 퐉 that is formed regularly on both sides of the base portion 81 in the thickness direction. And a convex portion 82 '}, and the base member 81 was a strip-shaped current collector having a thickness t ₇ of 10 µm and a maximum thickness t ₈ of 26 µm. In the width direction (long direction) X, the row units 83 in which the convex portions 82 are arranged in a row at a pitch P ₅ are formed. In the short direction Y, the row units 83 are arranged in parallel at the pitch P ₆ . In addition, the row units 83 and the row units 83 adjacent thereto are arranged such that the convex portions 82 are shifted by 0.5P ₅ minutes in the width direction X. The arrangement pattern of the convex portions 82 is the closest charging arrangement.

In the current collector 80, the boundary portion 82a of the base portion 81 and the convex portion 82 is formed of a curved surface. Thereby, workability at the time of compression processing and the release property from the roller 28 of the collector 80 are improved. At the same time, since the circular convex portions 82 are arranged closest to each other, the current collector 80 has sufficient durability against tensile stress applied to the long direction X. For this reason, it can prevent that deformation | transformation and the distortion locally generate | occur | produce in the collector 80 at the time of manufacture of the collector 80, the process of the collector 80, etc.

Moreover, when the surface roughness of the collector 80 was measured by the surface roughness machine, the surface 81a of the base material part 81 is smaller in surface roughness than the copper foil before processing. The surface roughness of the surface 81a of the base material portion 81 was almost the same as the surface roughness of the ceramic roller 28.

On the other hand, the surface roughness of the front end surface of the convex part 82 was substantially the same as copper foil before a process. Moreover, when the front surface of the convex part 82 was observed with the scanning electron microscope, the minute scratches recognized by copper foil before a process were recognized.

Moreover, when the crystal orientation analysis was performed by the back-scattering electron diffraction image (EBSP) method about the electrical power collector 80, the inside of the surface 81a of the base part 81 and the convex part 82 is copper before processing. It can be seen that the crystal grains are finer than the foil. Moreover, as a result of measuring the tensile strength of the electrical power collector 80, although the thickness of the base material part 81 becomes thinner than the copper foil before a process, the fall of tensile strength is not recognized and it is not recognized for the work hardening by compression processing. It is estimated that the tensile strength improved by this.

From the above analysis results, by performing the above processing on the copper foil, plastic deformation occurs in the portion of the convex portion 82 in accordance with compression processing, and compression processing is performed on the surface 81a of the base portion 81. It is considered that the current collector 80 has been obtained.

The current collector 85 obtained above was mounted inside the vacuum vapor deposition apparatus provided with the electron beam heating means. As a target, vapor deposition was carried out using silicon having a purity of 99.9999% and introducing oxygen having a purity of 99.7%, and a SiO _0.5 layer having a thickness of 25 μm was formed on the surfaces of the convex portions 87 on both sides of the current collector 85 in a columnar shape. Formed. This was slitted to a predetermined width to produce a negative electrode plate.

In the current collector 80, as shown in Fig. 16 (a), almost circular convex portions 82 are formed in the closest filling arrangement on both surfaces thereof, and the base portion 81 and the convex portions 82 are formed. The boundary portion 82a is formed of a curved surface. For this reason, when depositing a negative electrode active material toward the longitudinal direction X of the electrical power collector 80, it can adhere to the surface of the convex part 82 efficiently.

Moreover, it has sufficient durability with respect to the tensile stress applied to the longitudinal direction X of the electrical power collector 80. As shown in FIG. For this reason, the current collector 85 may be used in a process of manufacturing the strip-shaped current collector 80, a process of depositing a negative electrode active material on the surface of the current collector 80, a process of slitting the negative electrode plate to a predetermined width, and the like. The occurrence of local deformations and skews is prevented. At the same time, the dropping of the negative electrode active material can be suppressed.

The cylindrical nonaqueous electrolyte secondary battery 40 shown in FIG. 12 was produced using the positive electrode plate obtained in Example 24 and the negative electrode plate obtained above. First, the positive electrode plate 50, the separator 52, the negative electrode plate 51, and the separator 52 were piled up in this order, and wound in the spiral shape, and the electrode group 41 was produced. As shown in FIG. 9, the electrode group 14 which wound the positive electrode plate 15 and the negative electrode plate 17 in the spiral shape through the separator 19 was further produced. The electrode group 41 was housed together with the insulating plate 44 inside the bottomed cylindrical battery case 47. A negative lead (not shown) drawn from the bottom of the electrode group 41 is connected to the bottom of the battery case 47, and then the positive lead 42 drawn from the top of the electrode group 41 is attached to the sealing plate 45. It connected and inject | poured the electrolyte solution (not shown) which consists of a predetermined amount of nonaqueous solvent to the battery case 47. Thereafter, the sealing plate 45 having the sealing gasket 46 attached to the circumferential edge is inserted into the opening of the battery case 47, and the opening of the battery case 47 is folded inward to be caulked and sealed. The non-aqueous secondary battery 40 of the invention was produced.

After fabricating the electrode group 41 wound in a spiral shape in the non-aqueous secondary battery 40, the electrode group 41 was disassembled and observed, so that both the positive electrode plate 50 and the negative electrode plate 51 had electrodes. No defects such as plate breakage or falling off of the active material layer were recognized. Although the non-aqueous secondary battery 40 was charged and discharged for 300 more cycles, the non-aqueous secondary battery 40 and the electrode group 41 were dismantled after 300 cycles without any cycle deterioration. Defect was not recognized.

This is because the thin film of the active material layer is formed in a columnar shape on the surface of the convex portion which has not been subjected to compression processing, so that the volume change due to the expansion of the thin film of the active material layer at the time of lithium occlusion and the shrinkage of the thin film of the active material layer at the time of lithium release. This is considered to be because the battery characteristics could be maintained by the effect of mitigating.

As described in the above embodiments, in the electrode plate for non-aqueous secondary batteries of the present invention, the boundary portion between the base portion and the convex portion of the current collector is composed of curved surfaces, so that the workability during compression processing and the releasability of the current collector are good. Do. In addition, since the tip surface of the convex portion of the current collector is not subjected to compression processing, processing distortion due to the processing does not remain, and the surface precision of the convex portion front surface is good, thus forming a uniform thin film active material layer. It is possible. Moreover, since the convex part is formed by the plastic deformation according to compression processing, the convex part front surface does not become small in surface roughness, but maintains the initial surface roughness. Therefore, it is thought that the adhesive force of a thin film active material layer is high.

From this point of view, in order to further increase the adhesion between the convex portion plane and the electrode active material mixture layer, it is considered that it is very effective to make the surface of the current collector before processing more rough.

Moreover, it is preferable to form the active material layer in the non-aqueous secondary battery of this invention in columnar shape on the front-end | tip surface of a convex part. As a result, volume change due to expansion of the active material layer during lithium occlusion and shrinkage of the active material layer during lithium release due to charge and discharge of the non-aqueous secondary battery is alleviated. As a result, defects such as breakage of the electrode plate due to charge and discharge and dropping of the active material layer are less likely to occur, and a nonaqueous secondary battery having high capacity and high reliability is obtained.

According to the manufacturing method of the electrical power collector and electrode plate for non-aqueous secondary batteries which concern on this invention, while ensuring the intensity | strength of the electrical power collector for manufacturing an electrode plate, an electrode active material is efficiently carried out on the convex part formed on the electrical power collector. Since a non-aqueous secondary battery that can be supported and has high reliability can be obtained, it is useful as a power source for portable electronic devices and the like, in which high capacity is desired along with the multifunctionality of electronic devices and communication devices.

Claims (21)

For a current collector, using a pair of processing means provided to form a pressing nip portion in which the surfaces are press-contacted with each other and the sheet-like article can pass therethrough, and a plurality of recesses formed on at least one surface thereof. A method of manufacturing a current collector for a nonaqueous electrolyte secondary battery, wherein the metal foil is passed through a pressure contact nip portion of a processing means to perform compression processing to form a plurality of convex portions on at least one surface of the metal foil for current collectors. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries of Claim 1 whose surface roughness of the front-end | tip surface of a convex part is substantially the same as the surface roughness of the metal foil for electrical power collectors before a compression process. 3. The tapered shape according to claim 1 or 2, wherein the cross section in a direction perpendicular to the surface of the concave portion gradually decreases in a direction parallel to the surface of the concave portion from the surface of the concave portion toward the bottom of the concave portion. Method for producing a current collector for a nonaqueous electrolyte secondary battery having a. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries in any one of Claims 1-3 which compresses and processes so that the volume of a convex part may be below the volume of the internal space of a recessed part. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries as described in any one of Claims 1-4 which compress-processes so that the volume of a convex part may be 85% or less of the volume of the internal space of a recessed part. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries as described in any one of Claims 1-5 in which the process means with which the some recessed part was formed in the surface, and the boundary of the recessed part and the surface of the said processing means is curved. 7. The curved surface of the boundary between the recess and the surface of the processing means is formed by forming the recess by laser processing, thereby eliminating the elevation of the boundary between the recess and the surface of the processing means, which is generated by laser processing. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries formed by doing. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries of Claim 7 which removes a protuberance by grinding | polishing with the diamond particle of the average particle diameter of 30 micrometers or more and less than 53 micrometers. The method for manufacturing a current collector for nonaqueous electrolyte secondary batteries according to any one of claims 6 to 8, wherein a plurality of grooves having a width of 1 µm or less and a depth of 1 µm or less are formed at the boundary between the recess and the surface of the processing means. . The method for manufacturing a current collector for nonaqueous electrolyte secondary batteries according to claim 9, wherein grooves are formed by polishing with diamond particles having an average particle diameter of 5 µm or less. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries in any one of Claims 1-10 in which a pair of processing means is a pair of rollers, and the recessed part is formed in the surface of at least one roller. 12. The method for manufacturing a current collector for nonaqueous electrolyte secondary batteries according to claim 11, wherein a surface coating layer containing cemented carbide, alloy steel or chromium oxide is formed on the surface of the roller on which the recess is formed and toward the inner space of the recess. The method for manufacturing a current collector for nonaqueous electrolyte secondary batteries according to claim 12, wherein a protective layer containing an amorphous carbon material is formed on the surface of the surface coating layer. The surface coating layer and the protective layer according to claim 12 or 13, wherein the surface coating layer and the protective layer are formed by physical vapor deposition using sputtering, physical vapor deposition using ion implantation, chemical vapor deposition using thermal deposition, and chemical vapor deposition using plasma deposition. A method for producing a current collector for nonaqueous electrolyte secondary batteries formed by at least one vapor phase growth method selected from the group consisting of methods. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries in any one of Claims 1-10 whose at least one roller is a roller provided with the ceramic layer on the surface, and the recessed part is formed in the surface of the ceramic layer. The manufacturing method of the electrical power collector for nonaqueous electrolyte secondary batteries of any one of Claims 1-10 which apply | coats a lubricating agent to the surface of the roller or the metal foil for electrical power collectors, and is drying. The method for producing a current collector for nonaqueous electrolyte secondary batteries according to claim 16, wherein the lubricant contains a fatty acid. A current collector for a nonaqueous electrolyte secondary battery, comprising: a base portion made of a metal foil for current collector; and a plurality of convex portions formed to extend outward from at least one surface of the base portion to the outside of the base portion, wherein the boundary between the base portion surface and the convex portion is curved. The positive electrode active material or the negative electrode on the surface of the current collector for nonaqueous electrolyte secondary batteries or the current collector for nonaqueous electrolyte secondary batteries manufactured by the method for producing a current collector for nonaqueous electrolyte secondary batteries according to any one of claims 1 to 17. The manufacturing method of the electrode for nonaqueous electrolyte secondary batteries which carries an active material. 20. The method for manufacturing a nonaqueous electrolyte secondary battery electrode according to claim 19, wherein the positive electrode active material or the negative electrode active material is supported on the surface of the convex portion of the current collector for nonaqueous electrolyte secondary battery. A nonaqueous electrolyte secondary battery containing a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte, At least one of a positive electrode and a negative electrode is an electrode manufactured by the manufacturing method of the electrode for nonaqueous electrolyte secondary batteries of Claim 19 or 20, The nonaqueous electrolyte secondary battery.

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