JP2008016581A - Electrode for accumulator device and manufacturing method therefor, and the accumulator device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an accumulator device, such as lithium battery and electric double layer, for fully reducing the internal resistance, by forming irregular patterns on one surface of an active material layer with improved reproducibility. <P>SOLUTION: The manufacturing method of an electrode for accumulator devices used for an accumulator device, such as a lithium battery and an electric double-layer capacitor comprises a first process for supplying an active material forming material 1, containing at least an electrode active material and a binder to the irregular pattern 3 formed on a die 2; a second process for making a collector 6 to the active material forming material via an adhesive member 7 fix, or the like; and a third process for separating the die from the active material forming material, to which the collector is fixed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electricity storage device such as an electric double layer capacitor. In addition, in such an electricity storage device, the present invention relates to an electrode for an electricity storage device constituting a positive electrode body and a negative electrode body, and a method for producing the electrode for the electricity storage device.

  2. Description of the Related Art In recent years, the performance of portable electronic devices and hybrid automobiles has been remarkably improved, and the demand for higher performance of power storage devices such as batteries used therefor has increased. In addition to improving the performance of conventional batteries such as primary batteries such as alkaline batteries and oxyride batteries, secondary batteries such as nickel metal hydride batteries and lithium ion batteries, next generation batteries such as fuel cells and next generation batteries such as electric double layer capacitors Development for practical use is also being promoted in new technical fields such as power storage devices.

  In particular, electric double layer capacitors are attracting attention, with a long cycle life, high current output, rapid charge / discharge, a wide temperature range, miniaturization, thinning, and weight reduction. Since it has many advantages such as being safe for the human body and being environmentally friendly, it has been actively developed as an electricity storage device to replace the battery.

  Although the means for generating electric energy is different, the basic configuration of the conventional battery and the electric double layer capacitor is not changed. In other words, it is composed of two pairs of electrodes for an electricity storage device consisting of a current collector and an active material layer formed on the surface of the current collector, a separator inserted between the two pairs of electricity storage devices, and an electrolyte. Yes. Whereas a conventional battery generates electric energy by an electrochemical reaction in an active material, an electric double layer capacitor generates electric energy by an electric double layer generated in the active material layer.

  Today, various approaches have been taken to improve the performance of electrical storage devices with the aim of improving the efficiency of electrical energy generation and reducing internal energy, in terms of material improvements and configuration improvements. Yes.

  In the electric double layer capacitor, for example, as described in Patent Document 1 below, the activated carbon-based kneaded material is integrated on the surface of the metal foil serving as the active material layer, and a minute width groove is formed in the kneaded material layer by stamping or cutting. By holding the electrolyte solution in this groove, the active material layer is efficiently impregnated with the electrolyte solution, and the utilization efficiency of the pores of the activated carbon constituting the active material layer is increased, and the capacitance is increased. The internal resistance can be reduced.

  Alternatively, as described in Patent Document 2 below, a cylindrical roller is pressed on the surface of the active material layer containing at least porous particles and a binder to form an uneven pattern on the surface of the active material layer As a result, the adhesion between the electrode active material and the conductive auxiliary material was increased, and the internal resistance was reduced.

JP 2004-303754 A JP-A-2005-33066

  However, in the methods described in Patent Document 1 and Patent Document 2, an uneven pattern is formed by stamping, cutting, and roller pressing on the active material layer formed into a sheet shape by rolling. The planar shape, cross-sectional shape, and size of the concavo-convex pattern that can be formed are limited, and the concavo-convex pattern cannot be formed with good reproducibility, so that the internal resistance is insufficiently reduced.

  Accordingly, a first object of the present invention is to obtain an electricity storage device such as a lithium battery or an electric double layer in which an uneven pattern is formed with good reproducibility on one side of an active material layer to sufficiently reduce internal resistance.

  A second object of the present invention is to facilitate the fixation of the current collector to the active material layer and to simplify the production of the electrode for the electricity storage device.

  A third object of the present invention is to simplify the manufacture of an electrode for an electricity storage device by facilitating filling of an uneven material pattern with an active material forming material.

  A fourth object of the present invention is to simplify the production of the electrode for an electricity storage device by facilitating the peeling of the mold from the active material forming material.

  A fifth object of the present invention is to obtain an electric double layer capacitor having a high output characteristic in which the internal resistance of the active material layer itself is low, the electrical connection between the active material layer and the current collector is also good. .

  Accordingly, the invention described in claim 1 is a method of manufacturing an electrode for an electricity storage device used for an electricity storage device such as a lithium battery or an electric double layer so as to achieve the first object, and is formed in a mold. A first step in which an active material forming material containing at least an electrode active material and a binder is supplied to the concavo-convex pattern; a second step in which a current collector is fixed to the active material forming material; and a current collector And a third step in which the mold is peeled off from the active material forming material to be fixed.

  In order to achieve the second object, the invention described in claim 2 is the method for manufacturing an electrode for an electricity storage device according to claim 1, wherein the second step is performed by using a pressure member or the like. The current collector is fixed to the active material forming material by being compressed by being pressed.

  The invention described in claim 3 is the method for manufacturing an electrode for an electricity storage device according to claim 1 or 2 in order to achieve the above third object, wherein a pressure member or the like is used in the second step. The current collector is fixed to the active material forming material while being filled with the active material forming material while being pressed and pressed into the concave portion of the uneven pattern.

  Invention of Claim 4 is a manufacturing method of the electrode for electrical storage devices of any one of Claim 1 thru | or 3 in order to achieve the said 4th objective, Comprising: The convex part side surface of the said uneven | corrugated pattern is provided. A draft angle is provided on the side surface of the convex portion as a tapered surface, and the mold is peeled from the active material forming material in the third step by the draft angle.

  The invention described in claim 5 is an electrode for an electricity storage device to achieve the first object, and is manufactured by the manufacturing method according to any one of claims 1 to 4. .

  According to a sixth aspect of the present invention, in order to achieve the first object, the power storage device is formed by using the power storage device electrode according to the fifth aspect.

  According to a seventh aspect of the invention, in order to achieve the fifth object, the electric storage device according to the sixth aspect is an electric double layer capacitor.

  And according to invention of Claim 1, the 1st process by which an active material formation material is supplied to the uneven | corrugated pattern formed in a metal mold | die, and the 2nd process by which a collector is fixed to an active material formation material And a third step in which the mold is peeled off from the active material forming material, it is possible to use a molding process technology with excellent releasability to increase the size on one side of the active material layer formed of the active material forming material. Lithium battery and electric double layer with high output characteristics by forming the concave / convex pattern with a very fine and sub-μm with an arbitrary shape with good reproducibility by reducing the internal resistance of the active material layer itself An electrode for an electricity storage device such as can be manufactured.

  According to the invention described in claim 2, since the current collector is fixed to the active material forming material by being pressurized in the second step, the density of the active material layer formed by the active material forming material is reduced. At the same time, the adhesion between the active material layer and the current collector is made stronger, the current collector is easily adhered to the active material layer, the productivity is improved, and the production of the electrode for the electricity storage device is simplified. Further reduction of internal resistance can be realized.

  According to the invention described in claim 3, in the second step, the current collector is fixed to the active material forming material while being filled with the active material forming material by being pressed into the concave portion of the uneven pattern by being pressurized. Therefore, the concave-convex pattern formed on the mold can be formed on the surface of the active material forming material with high accuracy, and the active material layer and the current collector are fixed together. The active material forming material is filled into the rugged pattern to improve the productivity by facilitating the filling of the active material forming material into the concavo-convex pattern, and the production of the electrode for the electricity storage device used for the electricity storage device such as a lithium battery or electric double layer is simplified can do.

  According to the fourth aspect of the present invention, since the draft is provided on the side surface of the convex portion of the concavo-convex pattern and the mold is peeled from the active material forming material in the third step by the draft, Productivity can be improved by using molding technology that makes molds easy to peel off and has excellent releasability, making it easier to manufacture electrodes for power storage devices used in power storage devices such as lithium batteries and electric double layers. .

  According to the invention described in claim 5, since the electrode for an electricity storage device used for an electricity storage device such as a lithium battery or an electric double layer is manufactured by the manufacturing method according to any one of claims 1 to 4, Using a molding technology that excels in moldability, a concave / convex pattern with a very fine size of μm and sub-μm and an arbitrary shape is formed on one side of the active material layer formed of the active material forming material with high reproducibility. An electrode for an electricity storage device that can be formed, has low internal resistance of the active material layer itself, and has high output characteristics can be manufactured.

  According to the invention described in claim 6, since the electricity storage device such as a lithium battery or an electric double layer is formed by using the electrode for electricity storage device according to claim 5, a molding technique with excellent releasability. Can be used to form a concavo-convex pattern having a very fine size of μm and sub-μm and having an arbitrary shape on one side of an active material layer formed of an active material forming material with good reproducibility. An electric storage device such as a lithium battery or an electric double layer having a low internal resistance and high output characteristics can be obtained.

  According to the seventh aspect of the invention, since the electricity storage device according to the sixth aspect is an electric double layer capacitor, the active material formed by the active material forming material can be formed using a molding technique having excellent releasability. An uneven pattern having a very fine size of μm and sub-μm and having an arbitrary shape can be formed on one side of the material layer with good reproducibility, the internal resistance of the active material layer itself is small, and the active material layer The electrical connection of the electric body is also good, and an electric double layer capacitor having high output characteristics can be obtained.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a method for manufacturing an electrode for an electricity storage device according to the present invention. The illustrated example is a method of manufacturing an electrode of an electric double layer capacitor among power storage devices, and is an example of manufacturing an electrode in which a concavo-convex pattern can be formed only on one side due to the thickness relationship. For the sake of clarity, the scale of each component is not considered.

  First, in the manufacturing method shown in FIG. 1, as shown to (A), the metal mold | die 2 is prepared. The mold 2 uses materials such as metal, ceramics, and glass, and uses known mold processing techniques such as a photolithography technique, an X-ray lithography technique, an etching technique, an electroforming technique, a machining technique, or the like. Made using a combination of processing techniques. In the illustrated example, a nickel-based alloy made by electroforming a Si master mold processed using a photolithography technique and an etching technique is used.

  An uneven pattern 3 having an arbitrary size and an arbitrary shape is formed on the mold 2 at an arbitrary position. In this example, the upper surface of the convex portion is 0.5 μm square, the base is 1 μm square, the height is 0.5 μm, and many patterns having tapered side surfaces are formed.

  Next, as shown in (B), the active material forming material 1 is supplied to the concavo-convex pattern 3 formed on the mold 2. The active material forming material 1 only needs to contain at least an electrode active material and a binder, and here, it is composed of an electrode active material, a binder, and a conductive auxiliary material, and the electrode active material is granular activated carbon particles, and the binder is Although carbon black is used as the fluorine-based polymer and the conductive auxiliary material and these materials are kneaded, it is not particularly limited to such materials.

  Then, as shown in (C), the active material forming material 1 may be directly pressed by a pressing member 5 made of a press head, a pressing plate, or the like. Here, the adhesive member 7 is formed on the active material forming material 1. The current collector 6 is placed via And as shown to (D), when the electrical power collector 6 is pressurized with the pressurization member 5, it dries, filling the active material formation material 1 in the recessed part of the uneven | corrugated pattern 3, and the active material formation material A current collector 6 is fixed to 1.

  As a method for filling the concavo-convex pattern 3 with the active material forming material 1, there are a method of applying by spin coating or spraying, a method of dipping, a doctor blade method, a method of rolling with a roller or the like in addition to pressurization.

  In the illustrated example, an adhesive member 7 having conductivity is used in order to make the active material forming material 1 and the current collector 6 more firmly fixed, but the adhesive member 7 has conductivity. It is not limited to.

  Thereafter, as shown in (E), the pressure member 5 is removed, and the mold 2 is peeled from the active material forming material 1, whereby the current collector 6 is formed on the active material layer 4 made of the active material forming material 1. The electrode 9 for an electric double layer capacitor to which is fixed is manufactured. An uneven pattern 8 having an arbitrary size and an arbitrary shape is formed on one side of the active material layer 4 formed of the active material forming material 1. The surface of the mold 2 on which the concave / convex pattern 3 is formed is preferably subjected to surface treatment so that the active material forming material 1 can be easily peeled off.

  Here, the draft side is provided with the convex side surface of the concavo-convex pattern 3 as a tapered side surface, and the die 2 is peeled off from the active material forming material 1 by the draft, so that the die from the active material forming material 1 is removed. 2 can be easily peeled off, and the productivity can be improved by using a molding technique having excellent releasability, and the production of the electrode for the electric double layer capacitor can be simplified.

  In the example shown in FIG. 1, the method for manufacturing the electrode of the electric double layer capacitor in the power storage device has been described. However, the power storage bias using a non-solid active material forming material such as a liquid or a paste may be used. For example, the present invention is not limited to the electric double layer capacitor, and can be similarly applied to a method for manufacturing another power storage device such as a lithium battery.

  As described above, the first step (step shown in FIGS. 1A and 1B) in which the active material forming material 1 is supplied to the uneven pattern 3 formed on the mold 2, and the active material forming material 1 In the second step (steps shown in FIGS. 1C and 1D) in which the current collector 6 is fixed, and in the third step in which the mold 2 is peeled from the active material forming material 1 (FIG. 1E). On the one side of the active material layer 4 formed of the active material forming material 1 using a molding technique having excellent mold release properties, and the size is very fine as μm and sub-μm. By forming the concavo-convex pattern 3 having the above shape with good reproducibility, an electrode for an electric double layer capacitor having a low internal resistance of the active material layer 4 itself and high output characteristics can be manufactured.

  In addition, since the current collector 6 is fixed to the active material forming material 1 by being pressurized in the second step, the density of the active material layer formed by the active material forming material 1 is increased, and at the same time, the active material The adhesion between the layer and the current collector 6 is made stronger, the current collector 6 is easily fixed to the active material layer, the productivity is improved, and the production of the electric double layer capacitor electrode is simplified. Reduction of internal resistance can be realized.

  Furthermore, in the second step, the current collector 6 is fixed to the active material forming material 1 while being filled with the active material forming material 1 in the recesses of the concavo-convex pattern 3 by being pressurized. The concave / convex pattern 3 can be accurately formed on the surface of the concave / convex pattern, and when the active material forming material 1 and the current collector 6 are fixed together, Filling the active material forming material 1 makes it easy to fill the concavo-convex pattern 3 with the active material forming material 1, thereby improving productivity and simplifying the production of the electrode for the electric double layer capacitor.

  FIG. 2 shows a method for manufacturing an electrode for an electricity storage device, which is another example of the present invention. This example is also a method of manufacturing an electrode of an electric double layer capacitor among power storage devices, and is an example of manufacturing an electrode in which a concavo-convex pattern can be formed only on one side due to the thickness relationship. For ease of understanding, the scale of each component is not considered.

  Similarly, as shown to (A), the metal mold | die 12 is prepared. The mold 12 is made by using the same mold material as that used in the method of manufacturing the electric double layer capacitor electrode 9 shown in FIG. 1 and using the same known mold processing technique. In the illustrated example, similarly, a nickel-based alloy manufactured by electroforming a Si master mold processed using a photolithography technique and an etching technique is used.

  Similarly, an uneven pattern 13 having an arbitrary size and an arbitrary shape is formed at an arbitrary position on the mold 12. In this example, the upper surface of the convex portion is 0.5 μm square and the base is 1 μm. A large number of patterns having a tapered side surface with a corner and a height of 0.5 μm are formed.

  Then, as shown in (B), the active material forming material 11 is supplied to the concave / convex pattern 13 formed on the mold 12 by, for example, a spin coating method, and the concave / convex pattern 13 is filled. The active material forming material 11 only needs to contain at least an electrode active material and a binder. Here, granular activated carbon particles are used as an electrode active material, a fluorine-based polymer is used as a binder, and carbon black is used as a conductive auxiliary material. Dispersed in solution is used. Then, the active material forming material 11 is dried after filling.

  Next, as shown in (C), a current collector 16 is placed on the active material forming material 11 via an adhesive member 17, and the current collector 16 is applied by a pressure member 15 such as a press head. By being pressed, the current collector 16 is fixed to the active material forming material 11 in a state where the concave portions of the uneven pattern 13 are filled with the active material forming material 11.

  In this example as well, in order to make the active material forming material 11 and the current collector 16 more firmly fixed, the adhesive member 17 having conductivity is used, but the adhesive member 17 has conductivity. Needless to say, it is not limited to.

  Thereafter, as shown in (D), the pressure member 15 is removed, and the mold 12 is peeled off from the active material forming material 11, thereby collecting current on the active material layer 14 formed of the active material forming material 11. The electric double layer capacitor electrode 19 to which the body 16 is fixed is manufactured. An uneven pattern 18 having an arbitrary size and an arbitrary shape is formed on one surface of the active material layer 14 formed of the active material forming material 11. Note that the surface of the mold 12 on which the concave / convex pattern 13 is formed is preferably subjected to surface treatment so that the active material forming material 11 can be easily peeled off.

  Here, since the draft side is provided with the convex side surface of the concavo-convex pattern 13 as the tapered side surface, and the die 12 is peeled off from the active material forming material 11 by the draft, the die from the active material forming material 11 is removed. 12 can be easily peeled off, and the productivity can be improved by using a molding technique having excellent releasability, and the production of an electrode for an electric double layer capacitor can be simplified.

  In the example shown in FIG. 2, the method for manufacturing the electrode of the electric double layer capacitor in the electricity storage device has been described. However, the electricity storage bias that uses a non-solid active material forming material such as liquid or paste may be used. For example, the present invention is not limited to the electric double layer capacitor, and can be similarly applied to a method for manufacturing another power storage device such as a lithium battery.

  As described above, the first step (step shown in FIGS. 2A and 2B) in which the active material forming material 11 is supplied to the uneven pattern 13 formed on the mold 12, and the active material forming material 11 A second step (step shown in FIG. 2 (C)) in which the current collector 16 is fixed, and a third step (step shown in FIG. 2 (D)) in which the mold 12 is peeled from the active material forming material 11. Therefore, on one side of the active material layer 14 formed of the active material forming material 11 using a molding technique having excellent releasability, the size is very fine such as μm and sub-μm and has an arbitrary shape. By forming the concavo-convex pattern 13 with good reproducibility, it is possible to manufacture an electrode for an electric double layer capacitor having a small internal resistance of the active material layer 14 itself and high output characteristics.

  In addition, since the current collector 16 is fixed to the active material forming material 11 by being pressurized in the second step, the density of the active material layer formed by the active material forming material 11 is increased, and at the same time, the active material The adhesion between the layer and the current collector 16 is made stronger, the current collector 16 is easily adhered to the active material layer, the productivity is improved, and the production of the electric double layer capacitor electrode is simplified. Reduction of internal resistance can be realized.

  Furthermore, in the second step, since the current collector 16 is fixed to the active material forming material 11 while being filled with the active material forming material 1 in the recesses of the concavo-convex pattern 13 by being pressurized, the active material is formed. The concave / convex pattern 13 formed on the mold 12 can be formed on the surface of the material 11 together with the concave / convex pattern 13 formed on the mold 12 together with the active material forming material 11 and the current collector 16. The active material forming material 11 is filled into the concave and convex patterns 13 so that the active material forming material 11 can be easily filled to improve productivity, and the production of the electrode for the electric double layer capacitor can be simplified.

  When the electric double layer capacitor is manufactured using the electric double layer capacitor electrodes 9 and 19 manufactured by using the manufacturing method shown in FIGS. 1 and 2 as described above, for example, as shown in FIG. One electric double layer capacitor electrode is a positive electrode body 103 composed of a current collector 101 and an active material layer 102 for exchanging electricity with the outside, and another electric double layer capacitor electrode is Similarly, a negative electrode body 104 including a current collector 101 and an active material layer 102 is used. In order to prevent contact between the positive electrode body 103 and the negative electrode body 104, a separator 105 is provided between them, and the positive electrode body 103, the negative electrode body 104, and the separator 105 are impregnated with an electrolytic solution and sealed in the case 106. Is done.

  Thereby, since the uneven patterns 8 and 18 are formed on one surface of the active material forming materials 1 and 11, the internal resistance of the active material layer 102 itself is low, and electrical connection between the active material layer 102 and the current collector 101 is also achieved. An electric double layer capacitor as a power storage device that is good and has high output characteristics can be obtained.

(A) thru | or (E) is a manufacturing-process figure of the electrode for electrical double layer capacitors which shows the manufacturing method of the electrode for electrical storage devices by this invention. (A) thru | or (E) is a manufacturing-process figure of the electrode for electric double layer capacitors which shows the manufacturing method of another electrode for electrical storage devices by this invention. FIG. 3 is a cross-sectional configuration diagram of an electric double layer capacitor which is an electricity storage device according to the present invention manufactured by the manufacturing process of FIGS. 1 and 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Active material formation material 2 Mold 3 Mold uneven | corrugated pattern 4 Active material layer 5 Pressure member 6 Current collector 7 Adhesive member 8 Active material layer uneven | corrugated pattern 9 Electric double layer capacitor electrode 11 Active material formation material 12 Gold Mold 13 Concavity and convexity pattern of mold 14 Active material layer 15 Pressure member 16 Current collector 17 Adhesive member 18 Concavity and convexity pattern of active material layer 19 Electric double layer capacitor electrode 101 Current collector 102 Active material layer 103 Positive electrode body 104 Negative electrode body 105 Separator 106 Case

Claims (7)

  A first step in which an active material forming material containing at least an electrode active material and a binder is supplied to the uneven pattern formed in the mold, and a second step in which a current collector is fixed to the active material forming material. And a third step in which the mold is peeled off from the active material forming material.   2. The method of manufacturing an electrode for an electricity storage device according to claim 1, wherein the current collector is fixed to the active material forming material by being pressurized in the second step.   2. The current collector is fixed to the active material forming material while being filled with the active material forming material in the concave portion of the uneven pattern by being pressurized in the second step. Or the manufacturing method of the electrode for electrical storage devices of 2.   The draft is provided on the side of the convex part of the concavo-convex pattern, and the mold is peeled off from the active material forming material in the third step by the draft. The manufacturing method of the electrode for electrical storage devices as described in 1 ..   An electrode for an electricity storage device, which is produced by the production method according to claim 1.   An electricity storage device formed using the electrode for an electricity storage device according to claim 5.   The electric storage device according to claim 6, wherein the electric storage device is an electric double layer capacitor.

Images