JP2018074117A - Current collector for power storage device, electrode for power storage device, lithium ion capacitor, and method for manufacturing electrode for power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current collector for a power storage device, which enables the decrease in internal resistance, and enables the suppression of a short circuit.SOLUTION: A current collector 2 for a power storage device according to the present invention is a rugged current collector 2 for a power storage device, having roughness. The height H1 of the roughness is 40 to 450 μm. The current collector is provided with 30 to 10000 through-holes 4 per 1 mm. The through-holes 4 have an aperture ratio of 0.1 to 70%.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a current collector for an electricity storage device, an electrode for an electricity storage device, a lithium ion capacitor, and a method for producing an electrode for an electricity storage device.

  In recent years, power storage devices such as lithium ion batteries and lithium ion capacitors are expected to be applied to electric vehicles or hybrid vehicles, and to solar power generation energy storage systems used in combination with solar cells. In particular, it has attracted attention in the fields requiring capacity and output, such as electric vehicles or hybrid vehicles.

  For example, the power storage device is required to be compact and have a high capacity in order to be disposed in a narrow space at a high temperature such as an engine room.

  In such an electricity storage device, a method of doping an electrode with lithium ions has been proposed, and a current collector having a through-hole has been proposed for efficiently doping the electrode active material layer with lithium ions. For example, Patent Document 1 proposes a method of manufacturing a lithium ion capacitor in which an electrode is manufactured by applying an electrode active material layer while irradiating a current collector with laser light to form a through hole, thereby improving productivity. ing.

  However, if the current collector is provided with a through hole as described in Patent Document 1, even if lithium ion can be doped in the electrode active material layer, there is a region in which the through hole is vacant, so the current collector There is a problem that the contact area between the electrode active material layer and the electrode active material layer is small, and the internal resistance cannot be reduced.

Therefore, in Patent Document 2, in order to reduce the internal resistance, in order to increase the contact area between the current collector and the electrode active material layer, instead of a flat current collector, a through-hole is opened and at the same time a protrusion is disposed on the current collector. Hybrid capacitors that reduce the internal resistance of the electrode by being formed thereon have been proposed. Specifically, in Patent Document 2, the area (A) where the electrode active material layer and the current collector are in contact with each other is larger than the plane current collector (B) that does not have protrusions and apertures. B = 1 times or more, the number of protrusions with respect to the electrode active material layer is 1 / mm ² or more, the ratio of protrusions in the electrode composition layer is 1% by volume or more, and the length (D) of protrusions is the electrode composition layer It has been found that the internal resistance can be reduced by setting 0 <D / L <1 with respect to the thickness (L).

Japanese Patent No. 5038957 Japanese Patent No. 5163216

However, Patent Document 2 describes that the number of protrusions is preferably 2 to 30 / mm ² , and the current collector of Patent Document 2 has a small number of protrusions on the electrode active material layer. Since the area where the electrode active material layer and the current collector are in contact with each other is small, the internal resistance cannot be sufficiently reduced. Further, in such an electricity storage device, the protrusion may penetrate the electrode active material layer to break the separator, causing a short circuit between the positive electrode and the negative electrode, and it has been difficult to extend the life of the electricity storage device.

  One of the objects according to some embodiments of the present invention is to provide a current collector for an electricity storage device that can reduce internal resistance and suppress a short circuit. Another object of some aspects of the present invention is to provide an electrode for an electricity storage device that can reduce internal resistance and suppress a short circuit, and a method for manufacturing the same. Another object of some aspects of the present invention is to provide a lithium ion capacitor including the above-described electrode for an electricity storage device.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the current collector for an electricity storage device according to the present invention is:
A current collector for an electricity storage device having irregularities,
The height of the unevenness is 40 μm or more and 450 μm or less,
30 to 10,000 through-holes are provided per 1 mm ² ,
The opening ratio of the through hole is 0.1% or more and 70% or less.

[Application Example 2]
In application example 1,
You may comprise a positive electrode.

[Application Example 3]
In application example 1 or 2,
The opening width of the through hole may be not less than 1 μm and not more than 170 μm.

[Application Example 4]
One aspect of the electrode for an electricity storage device according to the present invention is:
A current collector having irregularities;
An electrode active material layer provided on the surface of the current collector;
Including
The height of the unevenness is 40 μm or more and 450 μm or less,
The current collector is provided with 30 to 10,000 through-holes per 1 mm ² ,
The opening ratio of the through hole is 0.1% or more and 70% or less.

[Application Example 5]
In application example 4,
It may be a positive electrode.

[Application Example 6]
In application example 4 or 5,
The height of the unevenness may be 10% or more and 95% or less with respect to the thickness of the electrode for the electricity storage device.

[Application Example 7]
In any one of Application Examples 4 to 6,
The opening width of the through hole may be not less than 1 μm and not more than 170 μm.

[Application Example 8]
One aspect of the lithium ion capacitor according to the present invention is:
The electrode for electrical storage devices as described in any one of the application examples 4-7 is included.

[Application Example 9]
One aspect of the method for producing an electrode for an electricity storage device according to the present invention is as follows.
Forming irregularities on the current collector using a roller;
Forming 30 or more and 10,000 or less through holes per 1 mm ^{2 in the current} collector;
Applying a slurry for electrode active material to the surface of the current collector;
Including
In the step of forming the irregularities,
The height of the unevenness is 40 μm or more and 450 μm or less,
In the step of forming the through hole,
The opening ratio of the through hole is set to 0.1% to 70%.

[Application Example 10]
In application example 9,
In the step of forming the through hole,
The current collector may be irradiated with laser light to form the through hole.

[Application Example 11]
In application example 10,
The energy of the laser beam may be not less than 0.1 μJ and not more than 20 μJ per one through hole.

  In the current collector for the electricity storage device according to the present invention, when the current collector is used for the electricity storage device, the contact area with the electrode active material layer can be increased, the internal resistance can be reduced, High energy can be achieved. Furthermore, in the electrical power collector for electrical storage devices which concerns on this invention, a short circuit can be suppressed and longevity can be achieved.

The top view which shows typically the electrode for electrical storage devices which concerns on this embodiment. Sectional drawing which shows typically the electrode for electrical storage devices which concerns on this embodiment. Sectional drawing which shows typically the electrode for electrical storage devices which concerns on this embodiment. Sectional drawing which shows typically the electrode for electrical storage devices which concerns on this embodiment. The perspective view which shows typically the electrode for electrical storage devices which concerns on this embodiment. The perspective view which shows typically the electrode for electrical storage devices which concerns on this embodiment. The flowchart for demonstrating the manufacturing method of the electrode for electrical storage devices which concerns on this embodiment. The schematic diagram for demonstrating the manufacturing method of the electrode for electrical storage devices which concerns on this embodiment. The schematic diagram for demonstrating the manufacturing method of the electrode for electrical storage devices which concerns on this embodiment. The flowchart for demonstrating the manufacturing method of the electrode for electrical storage devices which concerns on the modification of this embodiment. The schematic diagram for demonstrating the manufacturing method of the electrode for electrical storage devices which concerns on the modification of this embodiment. Sectional drawing which shows typically the lithium ion capacitor which concerns on this embodiment. Sectional drawing which shows typically the lithium ion capacitor which concerns on this embodiment. The top view which shows typically the state by which the winding body of the lithium ion capacitor which concerns on this embodiment was expand | deployed. Sectional drawing which shows typically the state by which the winding body of the lithium ion capacitor which concerns on this embodiment was expand | deployed. The table | surface which shows each parameter of the electrode for lithium ion capacitors. The table | surface which shows each parameter of the electrode for lithium ion capacitors. The table | surface which shows each parameter of a lithium ion capacitor.

  Preferred embodiments of the present invention will be described below with reference to the drawings. It should be understood that the present invention is not limited only to the embodiments described below, and includes various modified examples that are implemented without departing from the scope of the present invention.

1. First, a storage device electrode 10 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing an electricity storage device electrode 10 according to the present embodiment. 2 and 3 are cross-sectional views taken along line AA in FIG. 1 schematically showing the electrode 10 for an electricity storage device according to the present embodiment. FIG. 4 is an enlarged view of FIG. FIG. 5 is a perspective view schematically showing the electricity storage device electrode 10 according to the present embodiment.

  1 to 5 show an X axis, a Y axis, and a Z axis that are orthogonal to each other. For convenience, the electrode active material layer 6 is not shown in FIGS. 3 and 4. Further, in FIG. 5, illustration of the through hole 4, the raised portion 4 a, and the electrode active material layer 6 is omitted.

  The electrode 10 for an electricity storage device may be used as a positive electrode of the electricity storage device (the current collector 2 may constitute a positive electrode), or may be used as a negative electrode of the electricity storage device (the current collector 2). May constitute a negative electrode), or may be used as a positive electrode and a negative electrode of an electricity storage device. As an electrical storage device containing the electrode 10 for electrical storage devices, a lithium ion capacitor, a secondary battery, and an electrical double layer capacitor are mentioned, for example. Below, the case where the electrical storage device containing the electrode 10 for electrical storage devices is a lithium ion capacitor is demonstrated. A lithium ion capacitor is a capacitor whose energy density is improved by adding lithium ions to the negative electrode material using a carbon-based material capable of occluding lithium ions as the negative electrode material while using the principle of a general electric double layer capacitor. .

  As shown in FIG. 1 to FIG. 5, an electricity storage device electrode 10 (hereinafter, also simply referred to as “electrode 10”) is an electricity storage device current collector 2 (hereinafter also simply referred to as “current collector 2”), An electrode active material layer 6.

1.1. Current collector The material of the current collector 2 is, for example, metal, carbon, conductive polymer, etc. In consideration of conductivity, the material of the current collector 2 is preferably metal. Specifically, the material of the current collector 2 is aluminum, platinum, nickel, tantalum, titanium, stainless steel, copper, other alloys, or the like.

  The current collector 2 may be subjected to a surface chemical treatment or a surface roughening treatment in order to reduce contact resistance with the electrode active material layer 6 or to improve adhesion with the electrode active material layer 6. Examples of the surface chemical treatment include acid treatment and chromate treatment. Examples of the surface roughening treatment include electrochemical etching treatment and etching treatment with acid or alkali.

  The planar shape (the shape viewed from the Z-axis direction) of the current collector 2 is, for example, a shape having a longitudinal direction on the X-axis and a short direction on the Y-axis direction. The planar shape of the current collector 2 may be a rectangle whose long side is the X-axis direction.

  The current collector 2 has irregularities. The unevenness of the current collector 2 is constituted by a recess 3a and a protrusion 3b. In the illustrated example, the concave portions 3a and the convex portions 3b of the current collector 2 are provided periodically (the peaks and valleys are periodically) in the X-axis direction, and the concave portions 3a and the convex portions 3b are also provided in the Y-axis direction. Are provided periodically. The concave portions 3a and the convex portions 3 of the current collector 2 are provided in a checkered pattern in plan view. Therefore, in a cross-sectional view as shown in FIG. 3, a gap between the two convex portions 3 b constituting the cut surface in FIG. 3 is closer to the −Y axis direction side than the convex portion 3 b constituting the cut surface. The convex part 3b located can be confirmed.

  The concave portions 3a and the convex portions 3 of the current collector 2 do not have to be provided in a checkered pattern as described above. For example, the current collector 2 is arranged in a predetermined direction as shown in FIG. Only (in the illustrated example, only in the X-axis direction) may be a shape in which the concave portions 3a and the convex portions 3b are provided periodically. For convenience, the electrode active material layer 6 and the raised portions 4a are not shown in FIG.

  The cross-sectional shape of the current collector 2 is, for example, a sine wave shape as shown in FIGS. 2 and 3. The cross-sectional shape of the current collector 2 is not particularly limited as long as it is corrugated, and may be, for example, a rectangular wave shape, a triangular wave shape, a trapezoidal wave shape, or a sawtooth wave shape. However, considering the applicability of the electrode active material slurry for forming the electrode active material layer 6 and the difficulty of short-circuiting, the cross-sectional shape of the current collector 2 is preferably sinusoidal or trapezoidal.

  The shape and size of the adjacent recesses 3a of the current collector 2 may be the same or different. The shape and size of the adjacent convex portions 3b of the current collector 2 may be the same or different. The concave portions 3a and the convex portions 3b of the current collector 2 may be arranged with regularity as shown in FIG. 5 or may be arranged randomly, but the electrode arranged with regularity is the electrode. It is more preferable because the flatness of the surfaces 6a and 6b of the active material layer 6 can be increased.

  The unevenness height H1 (see FIG. 2) of the current collector 2 is 40 μm or more and 450 μm or less, preferably 45 μm or more and 440 μm or less. If the height H1 of the unevenness is smaller than 40 μm, the contact area between the current collector 2 and the electrode active material layer 6 is reduced and the adhesion is lowered, and the contact resistance between the current collector 2 and the electrode active material layer 6 is reduced. May be larger. On the other hand, when the height H1 of the unevenness is larger than 450 μm, the strength of the current collector 2 is reduced, and the current collector 2 may be easily cut. Furthermore, if the height H1 of the unevenness is larger than 450 μm, it may be difficult to apply the electrode active material slurry to the current collector 2, and air pockets may be generated in the recess 3a. Therefore, by setting the height H1 of the unevenness within the above range, the contact resistance between the current collector 2 and the electrode active material layer 6 can be reduced, and the strength of the current collector 2 can be increased, so Can be suppressed.

  As shown in FIG. 2, the height H1 of the unevenness of the current collector 2 refers to the bottom of the adjacent concave portion 3a (the portion located closest to the −Z-axis direction in the illustrated example) and the top of the convex portion 3b ( In the example shown in the figure, the distance in the Z-axis direction between the portion located closest to the + Z-axis direction). More specifically, it is a value measured by the method described in Examples described later. Note that the “unevenness of the current collector 2” does not include unevenness due to the surface roughness of the current collector 2.

The height H1 of the unevenness of the current collector 2 is, for example, 10% or more and 95% with respect to the thickness H2 of the electricity storage device electrode 10 (ratio of the height H1 to the thickness H2 (H1 / H2)). Or less, preferably 50% or more and 80% or less. If the ratio (H1 / H2) is smaller than 10%, the contact area between the current collector 2 and the electrode active material layer 6 may be reduced, and the adhesion may be reduced. On the other hand, if the ratio (H1 / H2) is greater than 95%, it becomes difficult to apply the electrode active material slurry to the current collector 2, and the current collector 2 is exposed on the surface of the electrode 10 for the electricity storage device. Electric storage device electrode 10
The yield may be reduced. Therefore, by setting the ratio (H1 / H2) in the above range, the adhesion between the current collector 2 and the electrode active material layer 6 can be improved, and the yield of the electrode for power storage device 10 can be improved.

  The thickness H2 of the electrode 10 for the electricity storage device is a distance between the surface 6a on one side and the surface 6b on the other side of the electrode active material layer 6. More specifically, it is a value measured by the method described in Examples described later.

  The current collector 2 is formed by processing a member that does not have an uneven shape (for example, a rectangular parallelepiped metal member) so as to have an uneven shape (processes unevenness). The thickness of the current collector 2 before being processed to be uneven is, for example, 0.5 μm or more and 50 μm or less, preferably 1 μm or more and 40 μm or less, and more preferably 2 μm or more and 35 μm or less. If the thickness of the current collector 2 before being processed to be uneven is less than 0.5 μm, the toughness of the current collector 2 is reduced, and there is a case where the current collector 2 is broken due to a crack caused by an impact or a tension applied in the manufacturing process. . On the other hand, if the thickness of the current collector 2 before being processed to be uneven is greater than 50 μm, the processability may be reduced when the current collector 2 is processed to be uneven, and unevenness having a desired shape may not be formed. is there. Therefore, by setting the thickness of the current collector 2 before the uneven processing to the above range, the current collector 2 can be prevented from being broken and the workability can be improved.

  The thickness of the current collector 2 after the unevenness processing is, for example, from 0.1 μm to 48 μm, preferably from 0.5 μm to 38 μm, and more preferably from 1 μm to 33 μm. When the thickness of the current collector 2 is smaller than 0.1 μm, there may be a high resistance. On the other hand, if the thickness of the current collector 2 is larger than 48 μm, it becomes difficult to make the current collector 2 uneven, so that the contact area between the current collector 2 and the electrode active material layer 6 is reduced. Resistance may be high. Furthermore, when the thickness of the current collector 2 is larger than 48 μm, the energy density when the current collector 2 is used for an electricity storage device may be reduced. Therefore, by setting the thickness of the current collector 2 within the above range, it is possible to obtain a power storage device with low resistance and high energy density. The thickness of the current collector 2 after the unevenness processing is smaller than the thickness of the current collector 2 before the unevenness processing.

  The thickness of the current collector 2 can be measured by, for example, observing the cut surface of the current collector 2 with a scanning electron microscope (SEM).

  The current collector 2 is provided with a through hole 4. An electrode active material layer 6 is filled in the through hole 4. In the example shown in FIG. 1, the planar shape of the through hole 4 is a circle, but may be a polygon such as a quadrangle. However, considering the electric field concentration at the corner, the planar shape of the through hole 4 is preferably circular. The through holes 4 may be arranged in a matrix form as shown in FIG. 1 or may be arranged at random. However, the arrangement of the through holes 4 in a matrix form makes the negative electrode more uniformly doped with lithium ions. It is more preferable because the property can be increased.

  Examples of the method of providing the through holes 4 in the current collector 2 include laser irradiation, etching processing (specifically, electrolytic etching processing), punching processing, and expanding processing. However, considering that the through hole 4 having a small hole diameter can be formed, the method of providing the through hole 4 in the current collector 2 is preferably laser irradiation or etching. Furthermore, considering that the generation of burrs can be further suppressed, laser irradiation and etching are preferable as a method of providing the current collector 2 with the through holes 4.

The number of the through-holes 4, on the surface 1 mm ² per collector 2, is 30 or more 10000 or less, preferably 8000 or less 70 or more, more preferably not more than 7000 more than 2000. If the number of through-holes 4 per 1 mm ² is less than 30, lithium ions will not easily pass through the current collector 2, and it may take time to pre-dope lithium ions into the negative electrode, which may increase the manufacturing cost. . On the other hand, if the number of through holes 4 per 1 mm ² is more than 10,000, the strength of the current collector 2 may be reduced. Further, if the number of through holes 4 per 1 mm ² is more than 10,000, processing for forming the through holes 4 becomes difficult, and the manufacturing cost may increase. Therefore, by setting the number of the through holes 4 of the surface 1 mm ² per collector 2 in the above range, it is possible to shorten the time of pre-doping of lithium ions, and to suppress the reduction in the strength of the current collector 2 Further, the manufacturing cost can be reduced.

  In the example shown in FIGS. 2 and 3, only one through hole 4 is provided in each of the recesses 3a and the protrusions 3b. However, this is for convenience and only one recess 3a. And the some through-hole 4 may be provided in the one convex part 3b.

The number of through-holes 4 per 1 mm ² is the number of through-holes 4 existing within the range of the projected area 1 mm ² of the current collector 2 that can be confirmed by SEM. For example, if the through-hole is halved on the 1 mm ² boundary line, it is converted to 0.5 and added to the other ½ through-hole.

In addition, when the through-hole 4 is formed by etching, the dry particle image analyzer is used to irradiate light from one side of the current collector 2 and perform data processing from the spread of transmitted light on the other side of the current collector 2. The diameter assumed to be circular may be calculated by calculating the diameter distribution and the number of samples having a unit area of 10 μm ² . Then, the number of the through holes 4 obtained, in terms of per unit area of 1 mm ^2, may be calculated the number of through-holes 4 per 1 mm ^2.

  The opening width of the through hole 4 is, for example, 1 μm or more and 170 μm or less, preferably 2 μm or more and 150 μm or less, and more preferably 5 μm or more and 140 μm or less. If the opening width of the through-hole 4 is smaller than 1 μm, the electrode active material layer 6 is difficult to enter the through-hole 4, and there are cases where a space is formed in the through-hole 4 and the electric field is concentrated. Therefore, lithium dendrite may be deposited. Furthermore, when the opening width of the through hole 4 is smaller than 1 μm, it becomes difficult for lithium ions to pass through the current collector 2, and it takes time to pre-dope lithium ions into the negative electrode, which may increase the manufacturing cost. On the other hand, when the opening width of the through-hole 4 is larger than 170 μm, the holding force due to the surface tension of the current collector 2 is reduced, and the electrode active material layer 6 is divided into a place where the through-hole 4 is provided and a place where the through-hole 4 is not provided. The film thickness may be different. As a result, the electric field is locally concentrated and lithium dendrite may be deposited. Furthermore, if the opening width of the through hole 4 is larger than 170 μm, the area of the current collector 2 may be reduced, and the resistance of the current collector 2 may be increased. Therefore, by setting the opening width of the through-hole 4 in the above range, the lithium ion pre-doping time can be shortened, and the electrode active material layer 6 can easily enter the through-hole 4. It is possible to increase the uniformity of the film thickness of the electrode active material layer 6 and further suppress the resistance of the current collector 2 from increasing.

  The opening width of the through hole 4 is the value of the diameter (hole diameter) when the planar shape of the through hole 4 is circular, and the length of the long axis when the planar shape of the through hole 4 is elliptical. When the planar shape of the through hole 4 is a polygon, it is the length of the longest line segment among the virtual line segments connecting the two vertices. The opening width of the through hole 4 can be measured, for example, by observing the surface of the current collector 2 with an SEM.

The opening ratio of the through hole 4 is 0.1% to 70%, preferably 1% to 60%, more preferably 2% to 50%. When the opening ratio of the through holes 4 is smaller than 0.1%, it may take time to pre-dope lithium ions into the negative electrode, which may increase the manufacturing cost. On the other hand, when the opening ratio of the through hole 4 is larger than 70%, the area of the current collector 2 is reduced, and the current collector 2 may have a high resistance. Therefore, by setting the aperture ratio of the through hole 4 in the above range, the pre-doping time of the lithium ion to the negative electrode can be shortened,
In addition, the resistance of the current collector 2 can be reduced.

  The aperture ratio of the through-hole 4 is obtained by measuring the mass of the current collector 2, and the apparent volume of the current collector 2 (the length of the current collector 2 in the X-axis direction × the length in the Y-axis direction × the length in the Z-axis direction) ) And the specific gravity of the current collector 2 is obtained. And an aperture ratio can be calculated | required by following formula (1).

  Opening ratio (%) = [1- (mass of current collector / specific gravity of current collector) / (apparent volume of current collector)] × 100 (1)

  As shown in FIG. 4, a raised portion 4 a is provided in the periphery (edge) of the through hole 4. The raised portion 4a is a portion where the current collector 2 melts and rises when the current collector 2 is irradiated with a laser to form the through-hole 4. The raised portion 4a is provided so as to surround the through hole 4 in plan view. The raised portion 4 a is provided on one surface 2 a and the other surface 2 b of the current collector 2. When the through-hole 4 is formed by laser irradiation, a raised portion 4a that rises smoothly is formed instead of the generation of burrs, and a short circuit between the positive electrode and the negative electrode due to burrs can be suppressed. Furthermore, the surface area of the current collector 2 can be increased by the raised portions 4a, and the contact area between the current collector 2 and the electrode active material layer 6 can be increased.

  The current collector 2 may have a main body portion made of, for example, a metal and a conductive adhesive layer provided on the surface of the main body portion. By the conductive adhesive layer, the adhesion between the current collector 2 and the electrode active material layer 6 can be improved, and the contact resistance between the current collector 2 and the electrode active material layer 6 can be lowered.

  The thickness of the conductive adhesive layer is, for example, 1 μm or more and 15 μm or less, preferably 2 μm or more and 10 μm or less, more preferably 2 μm or more and 5 μm or less. When the thickness of the conductive adhesive layer is smaller than 1 μm, the contact resistance between the current collector 2 and the electrode active material layer 6 may be increased. On the other hand, if the thickness of the conductive adhesive layer is greater than 15 μm, the electrical conductivity between the main body portion of the current collector 2 and the electrode active material layer 6 may be insufficient, and the resistance may increase. Therefore, by setting the thickness of the conductive adhesive layer in the above range, the contact resistance between the current collector 2 and the electrode active material layer 6 is lowered, and the main body portion of the current collector 2 and the electrode active material layer 6 Can be ensured.

  As the conductive adhesive layer, for example, a conductive adhesive obtained by dissolving or dispersing a conductive agent, a binder, and a thickener in a solvent is used.

  The conductive agent used for the conductive adhesive is not particularly limited as long as it has conductivity. For example, carbon black such as acetylene black and ketjen black (registered trademark of Akzo Nobel Chemicals Besloten Fennaut Shap), Graphite or the like is preferable. These conductive agents can be used alone or in combination of two or more. The volume average particle diameter of the conductive agent used for the conductive adhesive is, for example, from 0.001 μm to 10 μm, preferably from 0.05 μm to 5 μm, and more preferably from 0.01 μm to 1 μm.

 The binder used in the conductive adhesive is, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), a fluorine-containing polymer such as a fluoroacrylic polymer, styrene-butadiene rubber (SBR), Examples thereof include polymer compounds such as diene polymers such as acrylonitrile-butadiene rubber (NBR), acrylate polymers, polyimides, polyamides, and polyurethanes. Furthermore, a cellulose derivative may be used as a thickener, and an ammonium salt of carboxymethyl cellulose is particularly preferable.

The conductive adhesive can be produced by mixing the above components and a solvent such as water using a mixer. Examples of the mixer include a ball mill, a sand mill, a pigment disperser, a crusher,
An ultrasonic disperser, a homogenizer, a planetary mixer, a Hobart mixer, or the like is used.

  Examples of the method for applying the conductive adhesive include a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, and a brush coating method.

1.2. Electrode Active Material Layer The electrode active material layer 6 is provided on the surface of the current collector 2. In the example shown in FIG. 2, the electrode active material layer 6 is provided on one surface 2 a and the other surface 2 b of the current collector 2 and the inner surface of the through hole 4. Although not shown, the electrode active material layer 6 may not be provided on either one of the surfaces 2a and 2b of the current collector 2. Further, a part of the current collector 2 is an electrode plain portion where the electrode active material layer 6 is not provided. The current collector 2 can be energized at the electrode uncoated portion.

  The surfaces 6 a and 6 b of the electrode active material layer 6 have higher flatness than the surfaces 2 a and 2 b of the current collector 2. The flatness of the surfaces 6a and 6b of the electrode active material layer 6 can be increased by applying a predetermined time after applying the electrode active material slurry for forming the electrode active material layer 6 to the current collector 2. it can. The surfaces 6a and 6b of the electrode active material layer 6 may be flat surfaces.

  When the electrode active material layer 6 is a positive electrode active material layer (positive electrode active material layer), the thickness of one side of the electrode active material layer 6 (the thickness of the electrode active material layer 6 on one surface of the current collector 2) ) Is, for example, 100 μm or more and 400 μm or less, preferably 150 μm or more and 380 μm or less. When the electrode active material layer 6 is a negative electrode active material layer (negative electrode active material layer), the thickness of the electrode active material layer 6 on one side is, for example, 20 μm to 200 μm, preferably 30 μm to 100 μm. It is. In the electricity storage device electrode 10, since the current collector 2 has irregularities, the electrode active material layer 6 can be formed even when the thickness of the electrode active material layer 6 is increased compared to an electrode in which the current collector does not have irregularities. The active material layer 6 is difficult to peel off from the current collector 2.

  The thickness of the electrode active material layer 6 on one side is, for example, the distance D1 between the bottom of the concave portion 3a of the surface 2a and the surface 6a and the distance D2 between the top of the convex portion 3b of the surface 2a and the surface 6a. And the average value. The distances D <b> 1 and D <b> 2 can be measured by observing a cross section of the electricity storage device electrode 10 with an SEM.

  The electrode active material layer 6 includes, for example, an electrode active material, a conductive additive, and a binder.

1.2.1. Electrode active material The shape of the electrode active material is, for example, powder, fiber, or filler.

  The positive electrode active material contained in the positive electrode active material layer may be any material as long as it can reversibly carry lithium ions and anions such as tetrafluoroborate. For example, an allotrope of carbon is used. Specifically, examples of the carbon allotrope include activated carbon and polyacene. Preferably, the positive electrode active material is activated carbon, specifically, activated carbon such as phenol, rayon, acrylic, pitch, or coconut shell. These allotropes of carbon can be used alone or in combination of two or more as the active material. When carbon allotropes are used in combination, two or more carbon allotropes having different average particle diameters or particle size distributions may be used in combination.

In order to increase the adsorption area of lithium ions on the surface of the positive electrode active material layer, the positive electrode active material preferably has a large specific surface area. Specifically, the specific surface area of the positive electrode active material is 1000 m ² / g or more, preferably 1200 m ² / g or more and 3200 m ² / g or less, more preferably 1500 m ² / g or more and 3000 m ² / g or less. is there.

  The 50% volume cumulative diameter (D50) of the positive electrode active material by the laser diffraction method is, for example, from 0.1 μm to 20 μm, preferably from 1 μm to 15 μm, more preferably from 2 μm to 10 μm.

  As the negative electrode active material contained in the negative electrode active material layer, a material capable of reversibly carrying lithium ions is used. Preferably, the negative electrode active material is a carbon material such as graphite, non-graphitizable carbon, hard carbon, coke, graphene, polyacene organic semiconductor (PAS), or the like. PAS is obtained by carbonizing a phenol resin or the like, activated as necessary, and then pulverized. A negative electrode active material can be used individually or in combination of 2 or more types according to the kind of electrode for electrical storage devices. When the negative electrode active materials are used in combination, two or more types of negative electrode active materials having different average particle diameters or particle size distributions may be used in combination.

  The 50% volume cumulative diameter (D50) of the negative electrode active material by the laser diffraction method is, for example, from 0.1 μm to 20 μm, preferably from 1 μm to 15 μm, more preferably from 2 μm to 10 μm. When the volume particle diameter of the negative electrode active material is in the above range, the electrode for an electricity storage device 10 can be easily molded and the capacity can be increased.

1.2.2. Conductive auxiliary The positive electrode active material layer may contain a conductive auxiliary as required. The conductive auxiliary agent is not particularly limited as long as it has conductivity, and a carbon allotrope or a metal is used, and preferably a carbon allotrope is used. Specifically, as the conductive assistant, conductive carbon black such as furnace black, acetylene black, and ketjen black (registered trademark of Akzo Nobel Chemicals Bethloten Fennaut Shap); graphite such as natural graphite and artificial graphite; Particulate conductive assistants composed of carbon allotropes such as Examples of the conductive assistant include fibrous conductive assistants made of carbon allotropes such as carbon fibers such as polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, and vapor grown carbon fibers. Examples of conductive assistants made of metal include particulate conductive assistants such as titanium oxide, ruthenium oxide, aluminum, and nickel; fibrous conductive assistants such as metal fibers. Among these, as a conductive support agent, carbon black is preferable, and acetylene black and furnace black are more preferable. These conductive assistants can be used alone or in combination of two or more.

  The 50% volume cumulative diameter (D50) of the conductive assistant by the laser diffraction method is preferably smaller than the 50% volume cumulative diameter (D50) of the electrode active material by the laser diffraction method, for example, 0.001 μm or more and 10 μm or less. The thickness is preferably 0.05 μm or more and 5 μm or less, and more preferably 0.01 μm or more and 1 μm or less. By setting the volume average particle diameter of the conductive assistant within the above range, high conductivity can be obtained with a smaller amount of use.

  The amount of the conductive assistant is, for example, from 0.1 to 50 parts by weight, preferably from 0.5 to 15 parts by weight, more preferably 1 to 100 parts by weight of the electrode active material. It is not less than 10 parts by weight. By setting the amount of the conductive additive in the above range, the capacity of the electricity storage device including the electrode for electricity storage device 10 can be increased, and the internal resistance can be lowered.

1.2.3. Binder The binder is not particularly limited as long as it is a compound having a binding force. Examples of the binder include fluorine-containing polymers such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and a fluorine acrylic polymer, styrene-butadiene rubber (SBR), and acrylonitrile-butadiene rubber (NBR). ) Polymer compounds such as diene polymers, acrylate polymers, polyimides, polyamides, polyurethanes, and the like. Especially, as a binder, a fluorine-containing polymer and a diene polymer are preferable. When these are used as the binder, the adhesion between the current collector 2 and the electrode active material layer 6 can be improved, and the density of the electrode active material layer 6 can be increased. The internal resistance can be lowered. Moreover, the flexibility of the electrode 10 for power storage devices can be improved. These binders can be used alone or in combination of two or more. The binder may be a binder having a core-shell structure obtained by stepwise polymerizing a mixture of two or more monomers.

  The amount of the binder is, for example, 1 part by weight or more and 20 parts by weight or less, preferably 2 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the electrode active material.

  The electricity storage device current collector 2 has the following characteristics, for example.

The current collector 2 has unevenness, the height of the unevenness is 40 μm or more and 450 μm or less, and 30 or more and 10,000 or less through holes 4 are provided per 1 mm ² . It is 0.1% or more and 70% or less. Thus, in the current collector 2, when the current collector 2 is used for an electricity storage device, the contact area with the electrode active material layer 6 can be increased, and the internal resistance can be reduced. Energy can be achieved (see “Experimental example” described later). Further, the current collector 2 can suppress a short circuit (see “Experimental Example” described later), and can achieve a long life.

  The current collector 2 constitutes a positive electrode. Here, when the current collector 2 constitutes a negative electrode (when used as a negative electrode), the current collector 2 has irregularities, so that the portion provided in the concave portion 3a of the negative electrode active material layer and the negative electrode active The portion of the material layer provided on the convex portion 3b may have a different lithium ion doping amount. As a result, there are places where the magnitude of the voltage applied to the negative electrode active material layer is different and the electric field is concentrated, and lithium dentride may precipitate (lithium precipitates in a dendritic shape). Therefore, by using the current collector 2 as the positive electrode and using the current collector without irregularities as the negative electrode, it is possible to suppress the short circuit due to a small internal resistance while suppressing the precipitation of lithium dentride. Can be obtained.

  In addition, when lithium dentride does not precipitate depending on the voltage applied to the negative electrode and the height of the unevenness, the current collector 2 can be used for both the positive electrode and the negative electrode. Thereby, the electrical storage device which has smaller internal resistance and can suppress a short circuit can be obtained.

  In the current collector 2, the opening width of the through hole 4 is 1 μm or more and 170 μm or less. Thus, in the current collector 2, the lithium ion pre-doping time can be shortened, and the electrode active material layer 6 can easily enter the through hole 4. It is possible to improve the thickness uniformity and further suppress the resistance of the current collector 2 from increasing.

  The electrode 10 for electrical storage devices has the following characteristics, for example.

  The electrode 10 includes a current collector for an electricity storage device (for example, current collector 2) according to the present invention. Therefore, the electrode 10 can reduce internal resistance and can suppress a short circuit, when the electrode 10 is used for an electrical storage device.

  In the electrode 10, the uneven height H <b> 1 is 10% or more and 95% or less with respect to the thickness of the electrode 10. Therefore, in the electrode 10, the adhesion between the current collector 2 and the electrode active material layer 6 can be improved, and the yield of the storage device electrode 10 can be improved.

  The electrode 10 is suitable for various applications such as an electric vehicle or a hybrid vehicle, a solar power generation energy storage system combined with a solar cell, a load leveling power source combined with a battery, an elevator energy regenerative power, and an AGV livestock power source. Can be used.

  The current collector 2 should be checked for the presence of burrs and metal powders by analysis using SEM, energy dispersive X-ray analysis (EDX), fluorescent X-ray analysis (XRF), etc., and metal indicators. Can do.

  Examples of the metal indicator include a heterocyclic aromatic compound or a heterocyclic aromatic compound derivative having a complex forming ability with a metal ion, an azo compound, and the like. Examples of the heterocyclic aromatic compound or the heterocyclic aromatic compound derivative include phenanthroline compounds, and specific examples include 1,10-phenanthroline and bathophenanthroline. The blending amount is preferably about 0.001 wt% or more and 5 wt% or less with respect to 100 wt% of water.

  Examples of the azo compound include thiazolyl azo compounds and pyridyl azo compounds.

  Specific examples of the thiazolylazo compounds include 1- (2-thiazolylazo) -2-naphthol, 4- (2-thiazolylazo) -resorcinol, 2- (2-thiazolylazo) -4-methylphenol, 2- (2- Thiazolylazo) -4-methoxyphenol, 1- (2-thiazolylazo) -2-naphthol-6-sulfonic acid, 2- (2-thiazolylazo) -4-chlorophenol and the like.

  Specific examples of the pyridylazo compound include 1- (2-pyridylazo) -2-naphthol, 4- (2-pyridylazo) -resorcinol, 2- (2-pyridylazo) -4-methylphenol, 2- (2- Pyridylazo) -chromotropic acid, 2- (2-pyridylazo) 4-methoxyphenol and the like.

  The azo compound is preferably contained in an amount of about 0.001 wt% to 5 wt% with respect to 100 wt% of the alcohol solvent.

  Examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and tert-butyl alcohol.

  In addition, when confirming the presence or absence of metal powder using an azo compound as a metal indicator, Hiroko Wada, Analytical Chemistry, Vol. 21, no. 4,543-550 (1972) can be referred to.

2. Next, a method for manufacturing an electrode for an electricity storage device according to the present embodiment will be described with reference to the drawings. FIG. 7 is a flowchart for explaining the manufacturing method of the electrode 10 for the electricity storage device according to this embodiment. FIG. 8 is a schematic view for explaining the method for manufacturing the electrode 10 for an electricity storage device according to this embodiment. For convenience, the illustration of the through hole 4 is omitted in FIG. 2 and 3, the shape of the current collector 2 is illustrated as a sine wave shape, but in FIG. 8, the shape of the current collector 2 is illustrated as a triangular wave shape.

First, as shown in FIG. 8, the unevenness | corrugation is formed in the electrical power collector 2 using the processing roller 7 (step S10). Specifically, the current collector 2 is conveyed by transporting the current collector 2 having no irregularities between the pair of processing rollers 7 and passing the current collector 2 between the pair of processing rollers 7. Concavities and convexities are formed in The surface of the processing roller 7 has an uneven shape. The transport direction of the current collector 2 is, for example, the vertical direction (for example, upward with respect to the direction in which gravity acts).

Next, 30 or more and 10,000 or less through holes 4 are formed in the current collector ² per 1 mm 2 of the surface of the current collector 2 (step S12). Specifically, the surface of the current collector 2 is irradiated with laser light from the laser 8 to form the through hole 4. In the illustrated example, laser light is irradiated from the surface 2 a side of the current collector 2, but laser light may be irradiated from the surface 2 b side of the current collector 2.

The type of the laser 8 is not particularly limited, but when an aluminum foil or a copper foil is used as the current collector 2, a CO ₂ laser having a wavelength of 9.3 μm is preferable. As the laser 8, a YAG laser or a UV laser may be used.

  The energy of the laser beam irradiated from the laser 8 is per through hole (per one through hole 4), for example, 0.1 μJ or more and 20 μJ or less, preferably 0.2 μJ or more and 15 μJ or less, and more Preferably, it is 0.3 μJ or more and 13 μJ or less. If the energy of the laser beam for one through-hole is smaller than 0.1 μJ, the amount of heat is too small to make the through-hole 4 difficult to form, and the movement of lithium ions is hindered, making it difficult to dope the negative electrode. . On the other hand, if the energy of the laser beam for one through hole is larger than 20 μJ, the amount of heat is too large, so that it is difficult to form the through hole 4 having a desired hole diameter, and it becomes difficult to control the hole diameter of the through hole 4. There is. Therefore, by setting the energy of the laser beam for one through hole in the above range, it is possible to form the through hole 4 that is difficult to prevent the movement of lithium ions and whose hole diameter can be easily controlled. Further, by setting the energy of the laser beam for one through hole to 0.3 μm or more and 13 μm or less, a smoother raised portion 4a can be formed.

  In addition, the method of forming the through-hole 4 is not limited to laser beam irradiation, For example, an etching process (chemical etching process and electrolytic etching process), a punching process, and an expanding process may be used.

  Next, the electrode active material slurry 5 is applied to the surface of the current collector 2 (step S14). Specifically, the electrode active material slurry 5 is applied from the slurry application part 9, and the electrode active material slurry 5 is applied to the surfaces 2 a and 2 b of the current collector 2 (double-sided application). In the illustrated example, the electrode active material slurry 5 is applied to the current collector 2 in a state where the current collector 2 is conveyed in the vertical direction (vertical application method). The electrode active material slurry 5 includes, for example, the above electrode active material, a conductive additive, and a binder. The electrode active material slurry 5 may further contain a cellulose derivative.

  Next, the electrode active material slurry 6 formed on the surface of the current collector 2 is dried and pressed to form the electrode active material layer 6 (step S16).

  Through the above steps, the electrode 10 can be manufactured.

  The manufacturing method of the electrode 10 for electrical storage devices has the following characteristics, for example.

  In the manufacturing method of the electrode 10, when it uses for an electrical storage device, the electrode 10 which can reduce internal resistance and can suppress a short circuit can be manufactured.

In the manufacturing method of the electrode 10, the through-hole 4 is formed by irradiating the current collector 2 with laser light. Therefore, in the method for manufacturing the electrode 10, it is possible to suppress the generation of burrs when the through hole 4 is formed, compared to the case where the through hole is formed by providing a plurality of concave portions and convex portions on the emboss roll, for example.

  In the manufacturing method of the electrode 10, the energy of the laser beam is 0.1 μJ or more and 20 μJ or less per through hole. Therefore, in the manufacturing method of the electrode 10, it is possible to form the through hole 4 that is difficult to prevent the movement of lithium ions and that can easily control the hole diameter.

  In the manufacturing method of the electrode 10, even if the electrode active material slurry 5 is applied to the current collector 2 by a vertical coating method, the current collector 2 has irregularities, so that the applied electrode active material slurry is applied. 5 is difficult to move downward due to gravity. Therefore, in the method for manufacturing the electrode 10, the electrode active material layer 6 with high flatness can be formed.

  In addition, in the manufacturing method of the electrode 10, the process of forming an unevenness | corrugation in the electrical power collector 2 (step S10), the process of forming the through-hole 4 in the electrical power collector 2 (step S12), and the electrical power collector 2 for electrode active materials The step of applying the slurry 5 (step S14) and the step of drying and pressing the slurry 5 for electrode active material (step S16) may all be performed in separate lines. Thereby, management in each process can be facilitated.

  In addition, as shown in FIG. 9, the electrode active material slurry 5 is not applied to the surfaces 2 a and 2 b of the current collector 2 at the same time, but first the electrode active material slurry 5 is applied to the surface 2 b of the current collector 2. Next, the electrode active material slurry 5 may be applied to the surface 2 a of the current collector 2. The formation of the through holes 4 by the laser beam may be performed simultaneously with the application of the electrode active material slurry 5 to the surface 2 b of the current collector 2.

3. Next, a method for manufacturing an electrode for an electricity storage device according to a modification of the present embodiment will be described with reference to the drawings. FIG. 10 is a flowchart for explaining a method for manufacturing the electrode 10 for an electricity storage device according to a modification of the present embodiment. FIG. 11 is a schematic diagram for explaining a method of manufacturing the electricity storage device electrode 10 according to a modification of the present embodiment.

  Hereinafter, in the manufacturing method of the electricity storage device electrode 10 according to the modified example of the present embodiment, differences from the above-described example of the electricity storage device electrode 10 manufacturing method according to the present embodiment will be described, and similar points will be described. Is omitted.

  In the method for manufacturing the electricity storage device electrode 10 according to this embodiment described above, as shown in FIGS. 7 and 8, the through-holes are formed in the current collector 2 after the step of forming irregularities in the current collector 2 (S 10). 4 was formed (S12).

  On the other hand, in the method of manufacturing the electricity storage device electrode 10 according to the modification of the present embodiment, as shown in FIGS. 10 and 11, before the step of forming irregularities on the current collector 2 (S 22), the current collection is performed. A step (S20) of forming the through hole 4 in the electric body 2 is performed.

  In addition, the process of forming the through-hole 4 in the current collector 2 (S20), the process of forming irregularities in the current collector 2 (S22), and the process of applying the electrode active material slurry 5 to the current collector 2 (S24) And the step of drying and pressing the electrode active material slurry 5 (S26) include the step of forming the through holes 4 in the current collector 2 (S12), and forming the irregularities in the current collector 2, respectively. The step (S10), the step of applying the electrode active material slurry 5 to the current collector 2 (S14), and the step of drying and pressing the electrode active material slurry 5 (S16) are the same.

In the method for manufacturing the electrode for electricity storage device 10 according to the modification of the present embodiment, the step of forming the through-hole 4 in the current collector 2 (S20) before the step of forming irregularities in the current collector 2 (S22). I do.
Therefore, in the manufacturing method of the electrode 10 for the electricity storage device according to the modification of the present embodiment, the depth of focus of the laser light is easily determined as compared to the case where the through hole 4 is formed by laser light irradiation after the unevenness is formed, The current collector 2 having a desired aperture ratio can be obtained.

  However, in the manufacturing method of the electrode 10 for an electricity storage device according to the modification of the present embodiment, the unevenness is formed in the current collector 2 after the through hole 4 is formed, so that the deformation of the through hole 4 or the current collector 2 is formed. Cracks are likely to occur. Therefore, in the method for manufacturing the electricity storage device electrode 10 according to the modification of the present embodiment, it is preferable that the current collector 2 is formed with irregularities in consideration of the hole diameter and the aperture ratio of the through holes 4.

4). Next, a lithium ion capacitor 100 according to this embodiment will be described with reference to the drawings. FIG. 12 is a cross-sectional view schematically showing the lithium ion capacitor 100 according to this embodiment. FIG. 13 is a cross-sectional view taken along the line BB of FIG. 12 schematically showing the lithium ion capacitor 100 according to the present embodiment. For convenience, in FIG. 12, the wound body 40 is illustrated in a simplified manner. In FIG. 13, the positive electrode 10a and the negative electrode 10b are shown in a simplified manner.

  The lithium ion capacitor 100 includes the electrode for an electricity storage device according to the present invention. Below, the lithium ion capacitor 100 which contains the electrode 10 for electrical storage devices as the positive electrode 10a and the negative electrode 10b is demonstrated. As shown in FIGS. 12 and 13, the lithium ion capacitor 100 includes an outer container 12 that becomes a negative electrode terminal, a sealing plate 20, a positive electrode terminal 30, and a wound body 40.

  As shown in FIG. 12, the outer container 12 has, for example, a cylindrical shape whose upper surface is open. Although not shown, the outer container 12 may have a rectangular parallelepiped shape whose upper surface is open. The material of the exterior container 12 is, for example, aluminum, copper, nickel, iron, stainless steel or the like. A wound body 40 and an electrolytic solution are accommodated in the outer container 12. For example, a negative electrode lead 16 is connected to the inner surface of the outer container 12. The negative electrode lead 16 electrically connects the inner surface of the outer container 12 and the negative electrode 10 b of the wound body 40. Therefore, the exterior container 12 also serves as a negative electrode terminal. The material of the negative electrode lead 16 is, for example, copper, stainless steel, nickel, or the like.

  The sealing plate 20 is fixed to the opening edge of the exterior container 12. The sealing plate 20 may be insulative or conductive, but when the sealing plate 20 is conductive, for example, an insulating member (see FIG. (Not shown).

  The positive terminal 30 is attached to an opening provided in the sealing plate 20. The material of the positive electrode terminal 30 is, for example, aluminum. For example, a positive electrode lead 14 is connected to the lower surface of the positive electrode terminal 30. The positive electrode lead 14 electrically connects the positive electrode terminal 30 and the positive electrode 10 a of the wound body 40. The material of the positive electrode lead 14 is, for example, aluminum.

  In the example shown in FIG. 12, the negative electrode lead 16 is electrically connected to the outer container 12, but the positive electrode lead 14 is electrically connected to the outer container 12, and the negative electrode lead 16 is at the position of the positive electrode terminal 30. It may be configured to be electrically connected to existing terminals (not shown).

The wound body 40 is accommodated in the outer container 12 and immersed in the electrolytic solution. As shown in FIG. 14, the wound body 40 includes a positive electrode 10 a, a negative electrode 10 b, a first separator 50, a second separator 55, and a lithium electrode 60. Here, FIG. 14 is a plan view schematically showing a state in which the wound body 40 is unfolded (a state before being wound). FIG. 15 is a cross-sectional view taken along the line CC of FIG. 14 schematically showing the wound body 40. For convenience, in FIGS. 14 and 15,
The positive electrode 10a and the negative electrode 10b are illustrated in a simplified manner.

  As shown in FIGS. 14 and 15, the wound body 40 includes, for example, a sheet-like first separator 50, a positive electrode 10 a, a second separator 55, and a negative electrode 10 b, which are stacked in this order from the winding start side S. It is wound around towards the end of winding E. In the illustrated example, the lithium electrode is fixed to the first separator 50 and wound together with the first separator 50 to form a wound body 40. The cross-sectional shape of the wound body 40 is spiral as shown in FIG.

  Although not shown, the cross-sectional shape of the wound body 40 may be a flat spiral. Although not shown, the positive electrode 10a, the negative electrode 10b, the separators 50 and 55, and the lithium electrode 60 do not have to form a wound body, and the sheet-like positive electrode, negative electrode, separator, and lithium electrode You may comprise the laminated electrode body laminated | stacked.

  As the separators 50 and 55, a porous material that is durable against the electrolytic solution, the positive electrode active material, and the negative electrode active material is used. Specifically, as the separators 50 and 55, for example, a microporous membrane or nonwoven fabric made of polyolefin such as polyethylene or polypropylene, a micro-thick membrane or nonwoven fabric made of cellulose and rayon, or pulp generally called electrolytic capacitor paper is used as a main raw material. A porous film is used. Further, a solid electrolyte may be used instead of the separator.

  The lithium electrode 60 is fixed to the first separator 50 with, for example, a tape, an adhesive, or the like. In the illustrated example, two lithium electrodes 60 are provided on the winding start side S and the winding end side E of the first separator 50 with the positive electrode 10a interposed therebetween. Therefore, in the wound body 40 shown in FIG. 13, the lithium electrode 60 is disposed at the center portion and the outer peripheral portion of the wound body 40. Although not shown, the number of lithium electrodes 60 is not particularly limited and may be one.

  The lithium electrode 60 functions as a lithium ion supply source. Specifically, in the wound body 40 as shown in FIG. 13, the lithium electrode 60 is oxidized by being immersed in the electrolytic solution in a state where the negative electrode 10 b and the lithium electrode 60 are electrically connected and short-circuited. Then, the electrons are ionized by flowing to the negative electrode 10b, and are released into the electrolytic solution as lithium ions. The lithium ions can be electrochemically doped into the negative electrode 10b (also referred to as “pre-dope”) via the electrolytic solution. As a result, the potential of the negative electrode 10b can be lowered. Lithium ions can pass through the porous separators 50 and 55 and the through holes 4 provided in the current collector 2 and can be pre-doped into the negative electrode 10b with good uniformity. The lithium electrode 60 includes, for example, a lithium foil and a metal foil (specifically, a copper foil).

  As the electrolytic solution, for example, a nonaqueous electrolytic solution in which an electrolyte is dissolved in an organic solvent is used.

Examples of the electrolyte used in the electrolytic solution include (C ₂ H ₅ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₃ (CH ₃ ) NBF ₄ , (C ₂ H ₅ ) ₄ NPF ₆ , LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiPF ₆ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) _{2 and the} like. The concentration of the electrolyte in the electrolytic solution is preferably at least 0.1 mol / liter or more, and preferably 0.5 mol / liter or more and 1.5 mol / liter or less in order to reduce the internal resistance due to the electrolytic solution. Further preferred.

Examples of the solvent (electrolyte solvent) used in the electrolytic solution include carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; lactones such as γ-butyrolactone; sulfolanes; Nitriles such as acetonitrile; These can be used alone or as a mixed solvent of two or more. Of these, carbonates are preferred.

5. Experimental Example An experimental example is shown below to describe the present invention more specifically. The present invention is not limited by the following experimental examples.

5.1. Production of positive electrode <Example 1 (S1)>
A conductive paint containing carbon black having a 50% volume cumulative diameter (D50) value of 3 μm is coated on both sides of an aluminum plate using a vertical die type double-side coating machine, and then dried under reduced pressure. As a result, a conductive layer was formed on the aluminum plate-like front and back surfaces to obtain a positive electrode current collector.

  Next, a positive electrode active material slurry was prepared by adding and dispersing activated carbon powder having a 50% volume cumulative diameter (D50) of 3 μm, a fluoroacrylic binder, and carboxymethylcellulose in water.

  Next, the plate-like positive electrode current collector is conveyed to a processing roller having irregularities and passed therethrough, so that the plate-like positive electrode current collector has sinusoidal irregularities (in the plan view, the concave and convex portions are A shape provided in a checkered pattern).

  Next, after irradiating a laser beam to form a through-hole having a predetermined through-hole diameter and opening ratio, a positive electrode active material slurry is applied to both surfaces of a positive and negative electrode current collector having an uneven shape, and the applied positive electrode The positive electrode active material layer was formed by drying and pressing the slurry for active material.

  Then, by cutting the positive electrode current collector, a positive electrode having a positive electrode active material layer on both sides of the positive electrode current collector and a positive electrode uncoated portion on which the positive electrode active material layer is not formed is prepared. The electrode S1 for a lithium ion capacitor was obtained.

  FIG. 16 is a table showing the parameters of the lithium ion capacitor electrode S1 and the lithium ion capacitor electrodes S2 to S9 and C1 to C7 described below.

<Example 2 (S2)>
A lithium ion capacitor electrode S2 was produced in the same manner as in Example 1 except that through holes were formed in the positive electrode current collector before the irregularities were formed in the positive electrode current collector.

<Example 3 (S3)>
The positive electrode active material slurry is applied to one surface of the positive electrode current collector, and at the same time, the other surface, which is the opposite surface of the coating surface, is irradiated with laser light to form a through hole. Next, the positive electrode active material slurry is formed on the other surface. A lithium ion capacitor electrode S3 was produced in the same manner as in Example 1 except that the positive electrode active material slurry applied on both sides was dried and pressed.

<Example 4 (S4) to Example 6 (S6)>
In Example 4 (S4) to Example 6 (S6), lithium ion capacitor electrodes S4 to S6 were produced in the same manner as in Example 1 except that the conditions were changed to those shown in FIG.

  Specifically, in Example 4, compared with Example 1, the aperture ratio was mainly increased and the number of through holes was increased. In Example 5, compared with Example 1, the through-hole diameter and the aperture ratio were mainly increased, and the number of through-holes was reduced. In Example 6, compared with Example 1, the through-hole diameter was mainly enlarged and the number of through-holes was decreased.

<Example 7 (S7)>
Other than forming a positive electrode current collector having sinusoidal irregularities by transporting and passing an electrolytic etching foil (electrolytically etched metal foil) having a predetermined aperture diameter and opening ratio to a processing roller having irregularities Produced a lithium ion capacitor electrode S7 in the same manner as in Example 1. That is, in the lithium ion capacitor electrode S7, the through hole was formed not by laser light but by electrolytic etching.

<Example 8 (S8) and Example 9 (S9)>
In Example 8 (S8) and Example 9 (S9), lithium ion capacitor electrodes S8, 9 were produced in the same manner as in Example 1 except that the conditions shown in FIG. 16 were changed.

  Specifically, in Example 8, the height of the unevenness was mainly increased as compared with Example 1. In Example 9, compared with Example 1, the height of the unevenness was mainly reduced.

<Comparative Example 1 (C1)>
A conductive layer was applied on both sides of an aluminum plate-like expanded metal by a die coater and dried, and a conductive layer was formed on both sides of the expanded metal to obtain a positive electrode current collector. Next, a positive electrode active material slurry was applied to both sides of the positive electrode current collector and dried, and the resulting coating film was pressed to form a positive electrode active material layer, thereby obtaining a lithium ion capacitor electrode C1. . That is, in the lithium ion capacitor electrode C1, the current collector does not have irregularities, and the through hole is not formed by the laser beam.

<Comparative Example 2 (C2) to Comparative Example 6 (C6)>
In Comparative Example 2 (C2) to Comparative Example 6 (C6), lithium ion capacitor electrodes C2 to C6 were produced in the same manner as in Example 1 except that the conditions were changed to those shown in FIG.

  Specifically, in Comparative Example 2, the height of the unevenness was mainly reduced as compared with Example 1. In Comparative Example 3, compared with Example 1, the height of the unevenness was mainly increased. In Comparative Example 4, compared with Example 1, the through-hole diameter and the aperture ratio were mainly increased, and the number of through-holes was reduced. In Comparative Example 5, compared with Example 1, the aperture ratio was mainly increased and the number of through holes was increased. In Comparative Example 6, compared with Example 1, the aperture ratio was mainly reduced and the number of through holes was reduced.

<Comparative Example 7 (C7)>
Although an attempt was made to produce an electrode for a lithium ion capacitor in the same manner as in Example 7, the number of through-holes was too large, and cracks and tearing occurred during machining with the machining roller, and the electrode could not be produced. .

<Reference example>
Form a through-hole diameter of 10 μm on the positive electrode current collector coated with the positive electrode active material slurry using an uneven mold, and dry and press the positive electrode active material slurry coated on both sides of the positive electrode current collector. Thus, a positive electrode active material layer was formed on both surfaces to produce a lithium ion capacitor electrode according to a reference example.

5.2. Production of Negative Electrode <Example 10 (S10)>
A negative electrode active material slurry containing a graphite-based composite powder having a 50% volume cumulative diameter (D50) value of 5 μm and an SBR binder was prepared.

The copper plate-like negative electrode current collector was conveyed to a processing roller having irregularities and passed therethrough to form a three-dimensional shape having sinusoidal irregularities on the plate-shaped negative electrode current collector. Next, laser light is irradiated to form through holes so as to have a predetermined hole diameter and aperture ratio, and the negative electrode slurry is applied to both surfaces of the negative electrode current collector having irregularities, and then applied to the negative electrode slurry. Was dried and pressed to form a negative electrode active material layer.

  Then, the negative electrode current collector is cut to prepare a negative electrode having a negative electrode active material layer on both sides of the negative electrode current collector and a negative electrode uncoated portion on which the negative electrode active material layer is not formed. The electrode S10 for lithium ion capacitors was obtained.

  FIG. 17 is a table showing parameters of the lithium ion capacitor electrode S10 and the lithium ion capacitor electrodes S11 to S13 and C8 to C14 described below.

<Example 11 (S11)>
A lithium ion capacitor electrode S11 was produced in the same manner as in Example 10 except that through holes were formed in the negative electrode current collector before the irregularities were formed in the negative electrode current collector.

<Example 12 (S12)>
A negative electrode active material slurry is applied to one surface of the negative electrode current collector, and at the same time, a laser beam is irradiated to the other surface opposite to the coated surface to form a through hole. Next, the negative electrode active material slurry is formed on the other surface. A lithium ion capacitor electrode S12 was produced in the same manner as in Example 10 except that the negative electrode active material slurry applied on both sides was dried and pressed.

<Example 13 (S13)>
A copper plate-like expanded metal was conveyed to a processing roller having irregularities and passed therethrough to form a negative electrode current collector having sinusoidal irregularities. Next, the negative electrode active material slurry is applied to both surfaces of the negative electrode current collector, and the negative electrode active material slurry applied to both surfaces is dried and pressed to form a negative electrode active material layer on both surfaces to form lithium. An ion capacitor electrode S13 was produced.

<Comparative Example 8 (C8) to Comparative Example 12 (C12)>
In Comparative Example 8 (C8) to Comparative Example 12 (C12), lithium ion capacitor electrodes C8 to C12 were produced in the same manner as in Example 10 except that the conditions were changed to those shown in FIG.

  Specifically, in Comparative Example 8, the uneven processing was not performed. In Comparative Example 9, compared with Example 10, the height of the unevenness was mainly increased. In Comparative Example 10, the height of the unevenness was mainly reduced as compared with Example 10. In Comparative Example 11, compared with Example 10, the aperture ratio was mainly reduced and the number of through holes was reduced. In Comparative Example 12, compared with Example 10, the through-hole diameter and the aperture ratio were mainly increased, and the number of through-holes was reduced.

<Comparative Example 13 (C13)>
A copper plate-like expanded metal was conveyed to a processing roller having irregularities and passed therethrough to form a negative electrode current collector having sinusoidal irregularities. Next, the negative electrode active material slurry is applied to both surfaces of the negative electrode current collector, and the negative electrode active material slurry applied to both surfaces is dried and pressed to form a negative electrode active material layer on both surfaces to form lithium. An ion capacitor electrode C13 was produced.

<Comparative Example 14 (C14)>
An electrolytic etching foil having a predetermined hole diameter and an opening ratio was used to form a negative electrode current collector having sinusoidal irregularities by transporting and passing through a processing roller having irregularities. There were too many, and it was not possible to produce an electrode due to cracking or tearing during processing with the processing roller 5.3. Production of Lithium Ion Capacitor First and second separators of cellulose and rayon mixed nonwoven fabric were prepared. And the positive electrode was arrange | positioned between the two lithium electrodes in the surface of a 1st separator. At this time, it arrange | positioned so that a positive electrode plain part (part in which the electrode active material layer of a positive electrode collector is not provided) may protrude from the other end edge of the long side direction of a 1st separator.

  Next, the second separator was laminated on the positive electrode so that the positive electrode plain portion protruded from the other end edge in the long side direction of the second separator. That is, the second separator was disposed at substantially the same position as the first separator.

  Next, the negative electrode was laminated on the second separator so that the negative electrode uncoated portion (the portion where the electrode active material layer of the negative electrode current collector was not provided) protruded from one side edge of the second separator in the long side direction. . Thus, the electrode laminated body was comprised. The positive electrode and the negative electrode were arranged so that the positive electrode active material layer and the negative electrode active material layer face each other with the second separator interposed therebetween. The electrode laminate was wound from one end of the electrode laminate so that the negative electrode was inside the stainless steel core rod.

  Next, a lithium electrode current collector is formed by crimping a lithium electrode current collector of a copper porous foil on a lithium metal foil on the surface of the first separator with a gap from the end of winding of the positive electrode. A wound electrode body was produced by fixing the body to the first separator with tape.

  Next, the outer peripheral surface including the end of the electrode body was covered with a polypropylene film and fixed with tape. A stainless steel core rod was formed after forming an electrode body, and the electrode body was pressed to form a flat wound electrode body. At this time, it adjusted so that a lithium electrode might be located in the flat part of a flat wound-type electrode body.

  The negative electrode plain part and the negative electrode lead were electrically connected by superimposing a negative electrode lead on the negative electrode plain part of the obtained wound electrode body and joining them by laser welding. Furthermore, the negative electrode lead was electrically connected by joining to the negative electrode terminal plate by laser welding.

  Next, the positive electrode lead was superimposed on the positive electrode plain portion of the electrode body and joined by laser welding to electrically connect the positive electrode plain portion and the positive electrode lead. Furthermore, the positive electrode lead was electrically connected to the positive electrode terminal plate by joining by laser welding.

  The negative electrode terminal plate and the positive electrode terminal plate were integrated with an aluminum sealing plate via a polypropylene resin holder by insert resin molding. The dimensions of the sealing plate were 15 mm (length) × 150 mm (width) × 1.5 mm (thickness).

  An electrode body (rolled body) was placed in an aluminum outer package of 15 mm (width) × 150 mm (length) × 100 mm (height). The opening of the rectangular outer container was sealed with a sealing plate and fixed by laser welding.

Next, an electrolytic solution in which LiPF ₆ was dissolved at a concentration of 1 mol / L in an ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate mixed solvent was injected from the hole formed in the sealing plate. Thereafter, an aluminum safety valve was welded to the hole formed in the sealing plate. In this way, a wound-angle type lithium ion capacitor was manufactured.

Examples 1 (S1) to 9 (S9) and 1 (C1) to 7 (C7) were used as the positive electrode of the lithium ion capacitor. As the negative electrode of the lithium ion capacitor, the above Example 10 (S10) to Example 12 (S12) and Comparative Example 8 (C8) to Comparative Example 13 (C13) were used. FIG. 18 is a table showing combinations of positive and negative electrodes and respective parameters of lithium ion capacitors according to Examples 14 to 23 and Comparative Examples 15 to 20.

5.4. Measurement method of each parameter <Measurement of energy density>
The lithium ion capacitor (cell) is charged at a constant current of 0.19 A until the cell voltage reaches 3.8 V, and then charged at a constant voltage of 3.8 V for 30 minutes, at a constant current of 0.19 A. The charge / discharge operation for discharging until the cell voltage reached 1.9 V was repeated 5 times. The capacity at the time of discharge in the fifth charge / discharge operation was defined as the cell capacity. The value obtained by dividing the product of the obtained cell capacity and average cell voltage by the volume of the cell was defined as the energy density (Wh / L). The energy density is shown in FIG. As an evaluation standard, 18.0 (Wh / L) or more is good.

<Measurement of DC internal resistance>
The cell is charged with a constant current of 1.9 A (time rate: 10 C) until the cell voltage reaches 3.8 V, and then a constant current-constant voltage charging is performed for 0.5 hour by applying a constant voltage of 3.8 V. Next, the battery was discharged at a constant current of 19 A (time rate 100 C) until the cell voltage reached 2.2V. At that time, an approximate straight line of the voltage after 1 second and after 3 seconds is taken and extrapolated to 0 seconds, and the difference (ΔV) between the extrapolated voltage and 3.8 V is divided by the current value 19A. DC internal resistance (DC-IR) was used. The DC internal resistance is shown in FIG. As an evaluation standard, 5.5 mΩ or less is good.

<Measurement of voltage difference>
The cell was charged to 3.8 V with a current of 10 C, and the initial cell voltage A was measured. Next, after carrying out constant voltage charge for 1 hour, it was left to stand at room temperature for 24 hours, then the cell voltage B was measured, and the voltage difference between the initial cell voltage A and the cell voltage B was confirmed. The voltage difference is shown in FIG. A large voltage difference means a short circuit. As an evaluation standard, 30 mV or less is favorable.

<Measurement of thickness on one side of electrode active material layer>
The electrode was taken out from the cell where the energy density, the direct current internal resistance, and the voltage difference were measured, and the operation of immersing in dehydrated dimethyl carbonate with stirring at 25 ° C. for 10 minutes was repeated three times, and pre-dried at 60 ° C. for 1 hour. The preliminarily dried electrode thus obtained was cut into a length of 2 cm and a width of 1 cm, and the cut cross section was observed with an SEM. A distance D1 from the bottom of the concave portion that is provided on the current collector and is in contact with the electrode active material layer to the surface of the electrode active material layer; and a distance D2 from the top of the convex portion that is in contact with the electrode active material layer to the surface of the electrode active material layer; 10 points were measured, and the average value of the obtained results was taken as the thickness of the electrode active material layer on one side. The distances D1 and D2 and the thickness of the electrode active material layer on one side are shown in FIGS.

<Measurement of current collector thickness, uneven height H1 and electrode thickness H2>
The thickness of the current collector was measured at an arbitrary measurement location on the electrode obtained by the above method by SEM observation, and the average value of the obtained results was defined as the current collector thickness. In addition, at any measurement location, the height from the bottom of the three-dimensional concave portion of the current collector to the top of the convex portion is measured, and the average value of the obtained height is calculated as the height of the three-dimensional unevenness ( The height of the unevenness was H1). In addition, the maximum distance between one surface of the electrode active material layer and the other surface is measured at 10 points at the same location where the height H1 of the unevenness is measured, and the average value of the obtained distances is measured The thickness was H2. FIGS. 16 and 17 show the thickness of the current collector, the height H1 of the unevenness, and the height H1 (%) of the unevenness with respect to the thickness H2 of the electrode.

  In FIG. 16 and FIG. 17, the “thickness of the plane current collector” is the thickness of the current collector before the uneven processing.

<Measurement of through-hole diameter and number of through-holes (when through-holes are formed by laser)>
About the collector of the electrode obtained by said method, the through-hole diameter of the collector and the number of through-holes were measured. The diameter of the through hole of the current collector was measured by SEM observation to measure the diameter of the open through hole. Further, the number of through holes per 1 mm ² was measured. At this time, if the through hole is halved on the 1 mm ² boundary line, it is converted to 0.5 and added to the other ½ through hole to be 1. The through-hole diameter and the number of through-holes are shown in FIGS.

  In FIG. 16 and FIG. 17, “laser irradiation amount” is energy used to form one through hole.

<Measurement of through-hole diameter and number of through-holes (when through-holes are formed by electrolytic etching)>
When the through-hole was formed by electrolytic etching, light was irradiated from one side using a dry particle image analyzer Morphologi G2 (manufactured by Sysmex Corporation), and a circular shape was assumed by data processing from the spread of transmitted light on the opposite side. The aperture was calculated, and the aperture distribution and number of samples with a unit area of 10 μm ² were determined. Next, the number of through holes was measured by converting per unit area of 1 mm ² .

<Measurement of aperture ratio>
In the current collector of the electrode obtained by the above method, the mass was measured, the current collector size (length × width × height) was measured to determine the apparent volume of the current collector, and the specific gravity was determined. And the aperture ratio was calculated | required by Formula (1) mentioned above. The aperture ratio is shown in FIGS. 16 and 17.

5.5. Measurement Results In Examples 14 to 23, good results were obtained in energy density, DC internal resistance, and voltage difference. 16 to 18, the height of the unevenness is set to 40 μm to 450 μm, the number of through holes is set to 30 to 10,000 per 1 mm ² , and the opening ratio of the through holes is set to 0.1% to 70%. It was found that the internal resistance can be reduced and the short circuit can be suppressed.

  In Comparative Example 15, since both the positive electrode (Comparative Example 1) and the negative electrode (Comparative Example 8) did not have irregularities, the adhesion between the electrode current collector and the electrode active material layer was lowered and the resistance became high. Furthermore, since the positive electrode and the negative electrode do not have irregularities, the thickness of the electrode active material layer cannot be increased, and the energy density of the cell is small.

  In Comparative Example 16, since the height of the unevenness of the negative electrode (Comparative Example 9) is large and the distance between the current collector and the surface layer of the electrode active material layer is large, the electron conductivity with the electrolytic solution is low, and the high resistance became. Furthermore, lithium dendride precipitated. Further, the height of the unevenness of the positive electrode (Comparative Example 2) was small, the thickness of the positive electrode active material layer could not be increased, and the energy density was small. Further, in Comparative Example 16, it is considered that the voltage difference is increased because the height of the unevenness of the positive electrode is large.

  In Comparative Example 17, since the height of the unevenness of the positive electrode (Comparative Example 3) is large and the distance between the current collector and the surface layer of the electrode active material layer is large, the electron conductivity with the electrolytic solution becomes low, and the high resistance became. Furthermore, in Comparative Example 17, the height of the unevenness of the negative electrode is large, so it is considered that the voltage difference has increased.

  In Comparative Example 18, since the through-hole diameter of the positive electrode (Comparative Example 4) was large, the number of through-holes was reduced, the migration of lithium ions was suppressed, and the lithium ion occlusion did not proceed well and the resistance became high. Also, in the negative electrode (Comparative Example 11) current collector, the number of through-holes was reduced, lithium ion migration was suppressed, and lithium ion occlusion did not proceed well, resulting in high resistance. As a result, the energy density as a cell also decreased.

  In Comparative Example 19, since the aperture ratio of the positive electrode (Comparative Example 5) was large, the conductive portion of the metal current collector was reduced and the resistance was high. Moreover, since the through-hole diameter of the negative electrode (Comparative Example 12) was large, the number of through-holes was reduced, the migration of lithium ions was suppressed, and the lithium ion occlusion did not proceed well, resulting in high resistance. As a result, the energy density as a cell also decreased.

  In Comparative Example 20, in the negative electrode (Comparative Example 13), the number of through holes was reduced, the migration of lithium ions was suppressed, and the lithium ion occlusion did not proceed well and the resistance became high. As a result, the energy density as a cell also decreased.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). The present invention also includes a configuration in which a non-essential part of the configuration described in the above embodiment is replaced with another configuration. Furthermore, the present invention includes a configuration that achieves the same effects as the configuration described in the above embodiment or a configuration that can achieve the same object. Furthermore, the present invention includes a configuration obtained by adding a known technique to the configuration described in the above embodiment.

2 ... Current collector for electricity storage device, 2a, 2b ... surface, 3a ... concave portion, 3b ... convex portion, 4 ... through hole, 4a ... raised portion, 5 ... slurry for electrode active material, 6 ... electrode active material layer, 6a , 6b ... surface, 7 ... processing roller, 8 ... laser, 9 ... slurry application part, 10 ... electrode for power storage device, 10a ... positive electrode, 10b ... negative electrode, 12 ... outer container, 14 ... positive electrode lead, 16 ... negative electrode lead, DESCRIPTION OF SYMBOLS 20 ... Sealing plate, 30 ... Positive electrode terminal, 40 ... Winding body, 50 ... 1st separator, 55 ... 2nd separator, 60 ... Lithium electrode, 100 ... Lithium ion capacitor

Claims (11)

A current collector for an electricity storage device having irregularities,
The height of the unevenness is 40 μm or more and 450 μm or less,
30 to 10,000 through-holes are provided per 1 mm ² ,
The current collector for an electricity storage device, wherein an opening ratio of the through hole is 0.1% or more and 70% or less. In claim 1,
A current collector for an electricity storage device constituting the positive electrode. In claim 1 or 2,
The current collector for an electricity storage device, wherein the opening width of the through hole is 1 μm or more and 170 μm or less. A current collector having irregularities;
An electrode active material layer provided on the surface of the current collector;
Including
The height of the unevenness is 40 μm or more and 450 μm or less,
The current collector is provided with 30 to 10,000 through-holes per 1 mm ² ,
The electrode for an electricity storage device, wherein an opening ratio of the through hole is 0.1% or more and 70% or less. In claim 4,
An electrode for an electricity storage device, which is a positive electrode. In claim 4 or 5,
The height of the unevenness is 10% or more and 95% or less of the electrode for an electricity storage device with respect to the thickness of the electrode for the electricity storage device. In any one of Claims 4 thru | or 6,
The opening width of the said through-hole is an electrode for electrical storage devices which is 1 micrometer or more and 170 micrometers or less.   The lithium ion capacitor containing the electrode for electrical storage devices of any one of Claims 4 thru | or 7. Forming irregularities on the current collector using a roller;
Forming 30 or more and 10,000 or less through holes per 1 mm ^{2 in the current} collector;
Applying a slurry for electrode active material to the surface of the current collector;
Including
In the step of forming the irregularities,
The height of the unevenness is 40 μm or more and 450 μm or less,
In the step of forming the through hole,
The manufacturing method of the electrode for electrical storage devices which sets the aperture ratio of the said through-hole to 0.1% or more and 70% or less. In claim 9,
In the step of forming the through hole,
The manufacturing method of the electrode for electrical storage devices which irradiates the said collector with a laser beam and forms the said through-hole. In claim 10,
The energy of the said laser beam is a manufacturing method of the electrode for electrical storage devices which is 0.1 microJ or more and 20 microJ or less per said through-hole.