JP2010157541A - Wound-type accumulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wound-type accumulator capable of obtaining high productivity by the fact that an electrolyte penetrates inside a wound electrode unit in a short time to uniformly dope an electrode with lithium ions in a short time. <P>SOLUTION: The wound-type accumulator includes: the wound electrode unit which is constituted by stacking and winding a cathode, having a positive active material capable of reversibly carrying and supporting lithium ions or anions, and an anode, having a negative active material capable reversibly carrying and supporting lithium ions, with a separator disposed therebetween, and in which an outermost peripheral portion or an innermost peripheral portion is the separator; a lithium ion supply source provided on an inner peripheral surface of the outermost peripheral portion or the innermost peripheral portion; and an electrolyte made of an aprotic organic solvent electrolytic solution of lithium salt. In the wound-type accumulator, the anode or cathode is doped with lithium ions by means of electrochemical contact of the anode or cathode with the lithium ion supply source, the percentages of the region, which are not covered with the lithium ion supply source in the inner peripheral surface of the outermost peripheral portion or innermost peripheral portion of the wound electrode unit, are 10 to 70%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wound storage power source having an electrode winding unit in which strip-shaped positive and negative electrodes are stacked and wound.

In recent years, a battery having a negative electrode made of a carbon material such as graphite and a positive electrode made of a lithium-containing metal oxide such as LiCoO ₂ has been developed. In this battery, by charging after assembling the battery, lithium ions are supplied from the lithium-containing metal oxide constituting the positive electrode to the negative electrode, and when further discharged, lithium ions are returned from the negative electrode to the positive electrode. It is a so-called rocking chair type battery, and it is called a lithium ion secondary battery because it uses only lithium ions for charging and discharging without using metal lithium for the negative electrode, and is distinguished from lithium batteries using lithium metal. . This lithium ion secondary battery is characterized by high voltage, high capacity, and high safety.

  In addition, while environmental problems are being highlighted, development of a clean energy storage system using solar power generation or wind power generation, and a power source used for an electric vehicle or a hybrid electric vehicle replacing a gasoline vehicle are being actively performed. Furthermore, recently, as power equipment and equipment such as power windows and IT-related equipment are improved in performance and functionality, development of a new power source having high energy density and high output density is required.

  In recent years, as a storage power source for applications that require high energy density and high output characteristics, a storage power source called a hybrid capacitor, which combines the storage principle of lithium ion secondary batteries and electric double layer capacitors, has been developed. Attention has been paid. In such a hybrid capacitor, a carbon material capable of inserting and extracting lithium ions is previously occluded and supported (hereinafter also referred to as “doping”) by a chemical method or an electrochemical method, and a negative electrode. An organic electrolyte capacitor having a negative electrode made of a carbon material that can obtain a high energy density has been proposed (see, for example, Patent Document 1).

  Such an organic electrolyte capacitor is expected to have high performance, but it takes a very long time when lithium ions are doped in advance on the negative electrode, and it is necessary to uniformly carry lithium ions on the entire negative electrode. In particular, it has been difficult to put into practical use as a large-sized high-capacity cell such as a cylindrical battery in which electrodes are wound or a square battery in which a plurality of electrodes are stacked.

  In order to solve such a problem, a positive electrode and a negative electrode each having a current collector formed with holes penetrating the front and back surfaces, each of which includes a negative electrode active material capable of reversibly carrying lithium ions, And a negative electrode winding unit wound in a state where the negative electrode and the negative electrode are stacked via a separator, and a lithium ion supply source provided on either the outer peripheral surface or the inner peripheral surface of the electrode winding unit And a wound-type storage power source in which lithium ions are doped into the negative electrode by electrochemical contact between the negative electrode and lithium metal has been proposed (see, for example, Patent Document 2).

In this wound-type storage power source, since the current collector is provided with holes that penetrate the front and back surfaces, the lithium ion supply source is disposed on either the outer peripheral surface or the inner peripheral surface of the electrode winding unit. However, the lithium ions move between the electrodes through the holes of the current collector without being blocked by the current collector, so that not only the negative electrode portion in the vicinity of the lithium ion source but also the lithium ion source It is possible to electrochemically dope lithium ions into the remote anode part.
And, as described above, the negative electrode in which lithium ions are preliminarily doped into a carbon material that can occlude and desorb lithium ions has a lower potential than activated carbon used in electric double layer capacitors. In addition, since the withstand voltage of the cell is improved and the capacity of the negative electrode is extremely large compared to the activated carbon, a high energy density can be obtained according to the wound-type storage power source provided with the negative electrode.

  However, in such a wound-type storage power source, since lithium metal is provided only on one of the outer peripheral surface and the inner peripheral surface of the electrode element, it takes a long time to uniformly dope lithium ions throughout the negative electrode. There is a problem that it is necessary. In addition, when a lithium ion supply source is provided only on the outer peripheral surface of the electrode winding unit, a high voltage and a high capacity can be obtained. Since it is necessary to use a source, there is a problem that the filling amount of the electrode is lowered and it is difficult to obtain a sufficiently high energy density.

  In order to solve such a problem, an electrode layer containing a positive electrode active material capable of reversibly carrying lithium ions and / or anions is formed on at least one surface of a current collector having holes penetrating the front and back surfaces. And a negative electrode in which an electrode layer containing a negative electrode active material capable of reversibly supporting lithium ions is formed on at least one surface of a current collector having a hole penetrating the front and back surfaces via a separator. A cylindrical electrode winding unit wound in a stacked state, and a lithium ion source is arranged on both the inner and outer peripheral surfaces of the electrode winding unit, and the negative electrode And / or a wound-type storage power source in which lithium ions are doped into the negative electrode and / or the positive electrode by electrochemical contact between the positive electrode and a lithium ion source. For example, see Patent Document 3.).

Japanese Patent Laid-Open No. 8-1007048 Japanese Patent No. 3485935 JP 2007-67105 A

However, in such a wound-type storage power source, it takes a long time for the electrolyte to penetrate, and a long period is required to uniformly dope lithium ions into the entire negative electrode, and high productivity is obtained. Not found out. This is presumably because the surface of the electrode winding unit is covered with the lithium ion supply source, so that the electrolytic solution is difficult to diffuse into the electrode winding unit.
Moreover, in the wound-type storage power source described in Patent Document 3, after assembling the electrode winding unit, the lithium ion supply source is arranged on the inner peripheral surface and the outer peripheral surface thereof, so the manufacturing process is complicated, This also has the problem that high productivity cannot be obtained.

  The present invention has been made based on the circumstances as described above, and its purpose is to allow the electrolyte to penetrate into the electrode winding unit in a short time and to uniformly dope lithium ions into the electrode in a short period of time. An object of the present invention is to provide a wound-type storage power source capable of obtaining high productivity.

In the wound storage power source of the present invention, an electrode layer containing a positive electrode active material capable of reversibly supporting lithium ions and / or anions is formed on at least one surface of a current collector having holes penetrating the front and back surfaces. And a belt-like negative electrode in which an electrode layer containing a negative electrode active material capable of reversibly carrying lithium ions is formed on at least one surface of a current collector having holes penetrating the front and back surfaces. And an electrode stack formed by stacking the positive electrode and the negative electrode through a separator, wound from one end thereof, and the outermost peripheral part and / or the innermost peripheral part is the cylinder Electrode winding unit,
A lithium ion source provided on the inner peripheral surface of the outermost peripheral portion and / or the inner peripheral surface of the innermost peripheral portion of the electrode winding unit; and
Comprising an electrolyte comprising an aprotic organic solvent electrolyte solution of a lithium salt,
A wound-type storage power source in which lithium ions are doped into the negative electrode and / or the positive electrode by electrochemical contact between the negative electrode and / or the positive electrode and the lithium ion supply source,
The ratio of the area not covered by the lithium ion supply source on the inner peripheral surface of the outermost peripheral portion and / or the outer peripheral surface of the innermost peripheral portion of the electrode winding unit provided with the lithium ion supply source is 10 respectively. It is characterized by being -70%.

In the wound-type storage power source of the present invention, the lithium ion supply source is preferably provided so as not to contact the positive electrode and the negative electrode by the separator.
The lithium ion supply source is preferably crimped or stacked on a metal current collector, and the metal current collector on which the lithium ion supply source is crimped or stacked is preferably made of a porous foil. preferable.

The electrode stack is formed by stacking the first separator, the negative electrode, the second separator, and the positive electrode in this order, and the one end side portion of the first separator is opposite to the surface on which the negative electrode is disposed. The lithium supply source provided on the inner peripheral surface of the innermost peripheral portion of the electrode winding unit is disposed on the surface of the electrode winding unit, and the electrode winding unit is configured by winding the electrode stack from one end thereof Is preferred.
Further, the electrode winding unit is configured such that the outermost peripheral part of the positive electrode is covered with the outermost peripheral part of the negative electrode through the separator, and the outermost peripheral part of the negative electrode is covered with the outermost peripheral part of the separator. It is preferable that a lithium supply source is provided on the inner peripheral surface in the outermost peripheral portion.

  The wound storage power source of the present invention is suitable as a lithium ion capacitor or a lithium ion secondary battery.

According to the present invention, the outermost peripheral part of the electrode winding unit provided with the lithium ion supply source and / or the inner peripheral surface of the innermost peripheral part has a region not covered with the lithium ion supply source, Since the ratio of this region is 10 to 70% with respect to the entire inner peripheral surface of the outermost peripheral part and / or innermost peripheral part of the electrode winding unit, the electrolyte solution can be quickly placed inside the electrode winding unit. Further, since lithium ions are uniformly doped in the entire electrode in a short period of time, high productivity can be obtained.
In addition, since the electrode stack is wound in a state where the lithium ion supply source is arranged in advance on the separator, the production of the electrode winding unit and the arrangement of the lithium ion supply source can be performed in the same process. Higher productivity can be obtained.

Hereinafter, a case where the wound type storage power source of the present invention is implemented as a wound type lithium ion capacitor (hereinafter also referred to as “wound type LIC”) will be described.
FIG. 1 is a cross-sectional view illustrating the configuration of an example of a wound LIC according to the present invention.
In this wound type LIC, the electrode winding unit 10 is provided in the outer container 20. As shown in FIG. 2, the electrode winding unit 10 includes an electrode stack 10A in which the negative electrode 12, the second separator 14, and the positive electrode 11 are stacked in this order on one surface of the first separator 13. From one end, the core rod 19 is wound around in a cylindrical shape. Here, the positive electrode 11 and the negative electrode 12 are disposed so that respective electrode layers, which will be described later, face each other with the second separator 14 interposed therebetween. In the illustrated example, the electrode stack 10 </ b> A is wound so that the first separator 13 is on the inner side, so that the innermost peripheral portion of the entire electrode winding unit 10 is the innermost periphery of the first separator 13. A portion 13a is provided. The negative electrode 12 is longer than the positive electrode 11, and the outermost peripheral portion of the positive electrode 11 is wound and covered with the outermost peripheral portion of the negative electrode 12, and the first separator 13 and the second separator 12 are further covered. The separator 14 is longer than the negative electrode 12, and the outermost peripheral portion of the negative electrode 12 is wound around the outermost peripheral portion of the first separator 13 and the outermost peripheral portion 14 a of the second separator 14 in this order. Thus, the outermost peripheral portion of the entire electrode winding unit 10 is made the outermost peripheral portion 14 a of the second separator 14.
In the present invention, the “positive electrode” means a pole on the side where a current flows out during discharging and a current flows in during charging, and the “negative electrode” refers to a current flowing in during discharging. This means the pole on the side where current flows out.

The inner circumferential surface of the innermost circumferential portion of the electrode winding unit 10 (the innermost circumferential portion 13a of the first separator 13), that is, the one surface on the one end side of the first separator 13 opposite to the one surface on which the negative electrode 12 is disposed. On the other surface, lithium ion supply sources 15 made of a plurality of rectangular film-like lithium metals respectively extending in the width direction of the first separator 13 (direction perpendicular to the paper surface in FIG. 1) are spaced apart from each other in the circumferential direction. The lithium ion supply source 15 is not in direct contact with each of the positive electrode 11 and the negative electrode 12 by the first separator 13. Further, the inner peripheral surface of the outermost peripheral portion of the electrode winding unit 10 (the outermost peripheral portion 14a of the second separator 14), that is, the surface of the other end portion of the second separator 14 is respectively A plurality of rectangular film-like lithium metal sources 16 extending in the width direction (perpendicular to the paper surface in FIG. 1) are arranged apart from each other in the circumferential direction. The separator 14 is not in direct contact with each of the positive electrode 11 and the negative electrode 12. In the present invention, the “inner peripheral surface” means a surface on the center side of the electrode winding unit, and the “outer peripheral surface” means a surface opposite to the inner peripheral surface.
Further, in the wound type LIC of this example, as shown in FIG. 3, the electrode winding unit 10 is fixed by being wound by the tape 25, whereby the electrode winding unit 10 is fixed to the outer container. The work accommodated in 20 becomes easy, and the assembly workability of the wound LIC is improved. Further, a positive electrode terminal 17 and a negative electrode terminal 18 that are electrically connected to the positive electrode 11 and the negative electrode 12 are drawn out from both ends of the electrode winding unit 10.
The exterior container 20 is filled with an electrolytic solution made of an aprotic organic solvent electrolyte solution of lithium salt.

In the present invention, the lithium ion supply sources 15 and 16 may be provided on at least one inner peripheral surface of the outermost peripheral portion and the innermost peripheral portion of the electrode winding unit 10. A region (hereinafter referred to as “non-occupied region”) of the inner peripheral surface of the outermost peripheral portion of the electrode winding unit 10 provided with 16 and / or the inner peripheral surface of the innermost peripheral portion not covered with the lithium ion supply sources 15 and 16. The ratio of R (the ratio of the area of the unoccupied region R to the area of the inner peripheral surface of the outermost peripheral portion and / or the ratio of the area of the unoccupied region R to the area of the inner peripheral surface of the innermost peripheral portion) , 10 to 70%, preferably 15 to 50%, more preferably 20 to 30%. If the ratio of the non-occupied region R is in the above range, the penetration of the electrolytic solution can be achieved in a short time, whereby lithium ions are uniformly doped in the entire negative electrode 12 in a short time, and the pre-doping can be performed in a short time. Completed.
When the proportion of the unoccupied region R is less than 10%, it takes a long time for the electrolyte solution to penetrate, so that a long time is required until the lithium ions are uniformly doped into the entire electrode layer 12a of the negative electrode 12 after all. Is not preferable because it is necessary. On the other hand, when the proportion of the unoccupied region R exceeds 70%, the area of the lithium ion supply sources 15 and 16 facing the positive electrode 11 and / or the negative electrode 12 is small, so that it takes a long time to complete the pre-doping. Since it requires, it is not preferable.
Further, the non-occupied region R is preferably distributed uniformly over the entire inner peripheral surface of the outermost peripheral portion and / or innermost peripheral portion of the electrode winding unit 10. For example, instead of using one lithium ion supply source having a small area, it is possible to secure a non-occupied region R having a predetermined area by arranging a plurality of small area lithium ion supply sources apart from each other. This is preferable because a wide flow path of the electrolyte can be secured. Further, when a lithium ion supply source that is made porous by punching or the like is used, it is more preferable because an unoccupied area having a predetermined area can be secured by one lithium ion supply source.

The positive electrode 11 and the negative electrode 12 (hereinafter, both are also referred to as “electrodes”) are each formed by forming an electrode layer on at least one surface of a strip-shaped current collector, and both have substantially the same structure. Therefore, the following description will be made with reference to the same drawing.
FIG. 4 is an explanatory plan view showing the electrode in the electrode winding unit in a developed state, and FIG. 5 is an explanatory view showing an AA section of the electrode shown in FIG. 4 in an enlarged manner.
In this example, the negative electrode 12 (positive electrode 11) is formed on one surface (upper surface in FIG. 5) of the strip-shaped negative electrode current collector 12a (positive electrode current collector 11a) via a base layer 12c (11c). An electrode layer 12b (11b) containing a substance is formed, and a negative electrode terminal 18 (positive electrode terminal 17) is stitched or cold, for example, on the other surface of the negative electrode current collector 12a (positive electrode current collector 11a). Fixed and connected by welding.
When the electrode layer 12b or the electrode layer 11b formed on both surfaces of the negative electrode current collector 12a or the positive electrode current collector 11a is used as the electrode, the electrode layer 12b or the electrode layer 11b is partially made of the negative electrode current collector. The negative electrode terminal 18 or the positive electrode terminal 17 can be connected to the electrode layer 12b or the electrode layer 11b by peeling from the body 12a or the positive electrode current collector 11a.
Here, the negative electrode terminal 18 and the positive electrode terminal 17 may be drawn separately from both ends of the electrode winding unit 10 or may be drawn from one end portion. Further, it is sufficient that one negative electrode terminal 18 and one positive electrode terminal 17 are provided, but it is preferable that a plurality of each of the negative electrode terminal 18 and the positive electrode terminal 17 is provided because the internal resistance is reduced.

The positive electrode current collector 11a and the negative electrode current collector 12a (hereinafter also referred to as “electrode current collector”) are made of a porous material having holes P penetrating the front and back surfaces. Examples of the form include expanded metal, punching metal, metal net, foam, or porous foil having through holes formed by etching.
The shape of the hole P of the electrode current collector can be set to a circular shape, a rectangular shape, or any other appropriate shape. Moreover, it is preferable that the thickness of an electrode electrical power collector is 20-50 micrometers from a viewpoint of intensity | strength and weight reduction.
The porosity of the electrode current collector is usually 10 to 79%, preferably 20 to 60%. Here, the porosity is calculated by [1− (mass of electrode current collector / true specific gravity of electrode current collector) / (apparent volume of electrode current collector)] × 100.
As the material of the electrode current collector, various materials generally used for applications such as organic electrolyte batteries can be used. Specific examples of the material of the negative electrode current collector 12a include stainless steel, copper, and nickel. Examples of the material of the positive electrode current collector 11a include aluminum and stainless steel.
By using such a porous material as an electrode current collector, lithium ions can be supplied even if lithium ion supply sources 15 and 16 are arranged on both the inner and outer peripheral surfaces of the electrode winding unit 10. Since it moves freely between each electrode through the hole P of an electrode electrical power collector from the sources 15 and 16, the negative electrode 12 and / or the positive electrode 11 can be doped with lithium ion.

In the present invention, at least a part of the holes P in the electrode current collector is closed with a conductive material that does not easily fall off. In this state, the electrode layers 11a and 12a are formed on one surface of the electrode current collector. Preferably, it is possible to improve the productivity of the electrode, and to prevent or suppress a decrease in the reliability of the storage power source caused by the electrode layers 11b and 12b dropping from the electrode current collector. be able to.
Further, by reducing the thickness of the electrode (total thickness of the electrode current collector and the electrode layer), higher energy density and output density can be obtained.
In addition, the shape and number of holes P in the electrode current collector are such that lithium ions in the electrolyte described later can move between the front and back of the electrode without being blocked by the current collector, and depending on the conductive material. It can set suitably so that it may block easily.

The electrode layer 12b in the negative electrode 12 contains a negative electrode active material capable of reversibly carrying lithium ions.
The negative electrode active material constituting the electrode layer 12b is, for example, a heat-treated product of graphite, non-graphitizable carbon, and aromatic condensation polymer, and the hydrogen atom / carbon atom number ratio (hereinafter referred to as “H / C”). ) Is a polyacene-based organic semiconductor (hereinafter referred to as “PAS”)) having a polyacene-based skeleton structure of 0.50 to 0.05, among which PAS has a high capacity. It is more preferable at the point obtained. For example, if a PAS having H / C of about 0.2 carries 400 mAh / g of lithium ions (discharges) and then discharges, a capacitance of 650 F / g or more is obtained, and a lithium of 500 mAh / g or more is obtained. When ions are supported (charged), a capacitance of 750 F / g or more is obtained. From this, it is understood that PAS has a very large capacitance.

  In the present invention, when an anode active material having an amorphous structure such as PAS is used, the potential decreases as the amount of lithium ions to be carried increases, so that the withstand voltage (charge voltage) of the obtained storage power source is reduced. Since the voltage rise rate (discharge curve slope) during discharge increases, the amount of lithium ions is appropriately set within the range of lithium ion storage capacity of the active material, depending on the required operating voltage of the storage power source. It is preferable to do.

  Since PAS has an amorphous structure, it does not undergo structural changes such as swelling / shrinkage due to the insertion / desorption of lithium ions, so it has excellent cycle characteristics. Since it has an isotropic molecular structure (higher order structure), it has excellent characteristics for rapid charge and rapid discharge, and is therefore suitable as a negative electrode active material.

  The aromatic condensation polymer that is a precursor of PAS is a condensate of an aromatic hydrocarbon compound and aldehydes. As the aromatic hydrocarbon compound, for example, phenols such as phenol, cresol and xylenol can be suitably used. Examples thereof include methylene / bisphenols, hydroxy / biphenyls, hydroxynaphthalenes and the like represented by the following formula. Of these, phenols, and particularly phenols, are suitable for practical use.

(In the formula, x and y are each independently an integer of 0 to 2.)

  The aromatic condensation polymer may be a modified aroma obtained by substituting a part of an aromatic hydrocarbon compound having a phenolic hydroxyl group with an aromatic hydrocarbon compound having no phenolic hydroxyl group, such as xylene, toluene, aniline, etc. A group condensation polymer such as a condensate of phenol, xylene and formaldehyde can also be used. Furthermore, a modified aromatic polymer substituted with melamine or urea can be used, and a furan resin is also suitable.

PAS is used as an insoluble and infusible substrate, and the insoluble and infusible substrate can also be produced, for example, from the aromatic condensation polymer as follows. That is, by gradually heating the aromatic condensation polymer to a temperature of 400 to 800 ° C. in a non-oxidizing atmosphere (including vacuum), H / C is preferably 0.5 to 0.05, preferably Can obtain an insoluble and infusible substrate of 0.35 to 0.10.
However, the method for producing an insoluble and infusible substrate is not limited to this. For example, in the method described in JP-B-3-24024, H / C is in the above range, and 600 m ² / g. It is also possible to obtain an insoluble and infusible substrate having a specific surface area by the above BET method.

  In the insoluble infusible substrate, according to X-ray diffraction (CuKα), the position of the main peak is represented by 2θ and is not more than 24 °, and in addition to the main peak, the position is 41 to 46 °. There are other broad peaks in between. That is, the insoluble infusible substrate has a polyacene skeleton structure in which an aromatic polycyclic structure is appropriately developed, has an amorphous structure, and can be stably doped with lithium ions. It is suitable as a negative electrode active material for a storage power source.

  In the present invention, the negative electrode active material preferably has a pore diameter of 3 nm or more and a pore volume of 0.10 mL / g or more, and the upper limit of the pore diameter is not limited, but is usually in the range of 3 to 50 nm. is there. Moreover, although it does not specifically limit about the range of pore volume, Usually, it is 0.10-0.5 mL / g, Preferably it is 0.15-0.5 mL / g.

In the wound LIC according to the present invention, the electrode layer 12b in the negative electrode 12 is formed on the negative electrode current collector 12a using a material containing a negative electrode active material such as the above carbon material or PAS. The method is not specified and a known method can be used. Specifically, a negative electrode active material powder, a binder and, if necessary, a slurry in which conductive powder is dispersed in an aqueous medium or an organic solvent are prepared, and this slurry is applied to the surface of the negative electrode current collector 12a. The electrode layer 12a can be formed by drying or by previously forming the slurry into a sheet shape and attaching the resulting molded body to the surface of the negative electrode current collector 12a.
Here, examples of the binder used for preparing the slurry include rubber-based binders such as SBR, synthetic fluorine-based resins such as polytetrafluoroethylene and polyvinylidene fluoride, and thermoplastic resins such as polypropylene and polyethylene. Among these, a fluorine-based resin is preferable as the binder, and a fluorine-based resin having a fluorine atom / carbon atom ratio (hereinafter referred to as “F / C”) of 0.75 or more and less than 1.5 is used. It is preferable that a fluororesin having an F / C of 0.75 or more and less than 1.3 is more preferable.
Although the usage-amount of a binder changes with kinds, electrode shape, etc. of a negative electrode active material, it is 1-20 mass% with respect to a negative electrode active material, Preferably it is 2-10 mass%.
Moreover, as an electroconductive material used as needed, acetylene black, a graphite, a metal powder etc. are mentioned, for example. The amount of the conductive material used varies depending on the electric conductivity of the negative electrode active material, the electrode shape, and the like, but it is preferably used at a ratio of 2 to 40% by mass with respect to the negative electrode active material.

When the electrode layer 12b is formed by applying the slurry to the negative electrode current collector 12a, as shown in FIG. 5, an underlying layer 12c of a conductive material is formed on the coated surface of the negative electrode current collector 12a. It is preferable to do. When the slurry is directly applied to the surface of the negative electrode current collector 12a, the negative electrode current collector 12a is a porous material, so that the slurry leaks from the hole P of the negative electrode current collector 12a, or the negative electrode current collector Since the surface of 12a is not smooth, it may be difficult to form the electrode layer 12b having a uniform thickness. Then, by forming the base layer 12c on the surface of the negative electrode current collector 12a, the hole P is blocked by the base layer 12c and a smooth coating surface is formed, so that the slurry can be easily applied, The electrode layer 12b having a uniform thickness can be formed.
In the illustrated example, the electrode layer 12b is formed on only one surface of the negative electrode current collector 12a. However, when the electrode layer 12b is formed on both surfaces of the negative electrode current collector 12a, for example, The negative electrode terminal 18 can be connected to the said uncoated area | region by intermittently apply | coating slurry to either of both surfaces, and forming the uncoated area | region in the negative electrode collector 12a.

  The thickness of the electrode layer 12b in the negative electrode 12 is designed in balance with the thickness of the electrode layer 11b in the positive electrode 11 so as to ensure a sufficient energy density for the obtained wound LIC. From the viewpoint of output density, energy density, industrial productivity, and the like, when formed on one surface of the negative electrode current collector 12a, it is usually 15 to 100 μm, preferably 20 to 80 μm.

The electrode layer 11b in the positive electrode 11 contains a positive electrode active material capable of reversibly carrying lithium ions and / or anions such as tetrafluoroborate.
The positive electrode active material constituting the electrode layer 11b is, for example, a heat-treated product of activated carbon, conductive polymer, aromatic condensation polymer, and has a polyacene skeleton structure with H / C of 0.05 to 0.50. PAS or the like can be used.
The electrode layer 11b in the positive electrode 11 can be formed by the same method as the electrode layer 2b in the negative electrode 12.

In the wound LIC according to the present invention, the potential of the positive electrode 11 and the negative electrode 12 after the positive electrode 11 and the negative electrode 12 are short-circuited is preferably 2.0 V or less.
In conventional electric double layer capacitors, generally the same type (mainly activated carbon) of the same type is used as the active material in the positive electrode and the negative electrode. This active material has a potential of about 3 V when the capacitor is assembled. When the capacitor is charged, an anion forms an electric double layer on the surface of the positive electrode, thereby increasing the potential of the positive electrode. On the other hand, the cation forms an electric double layer on the surface of the negative electrode, thereby lowering the potential of the negative electrode. Conversely, during discharge, anions are released from the positive electrode and cations are released from the negative electrode into the electrolyte, respectively, so that the potential drops or rises, and finally the potential becomes about 3V. Thus, since the normal carbon material has a potential of about 3 V, the organic electrolyte capacitor in which the carbon material is used for both the positive electrode and the negative electrode has the positive electrode and the negative electrode after the positive electrode and the negative electrode are short-circuited. Each of the potentials is about 3V.

In contrast, in the wound LIC according to the present invention, the potential of the positive electrode 11 after the positive electrode 11 and the negative electrode 2 are short-circuited as described above is 2.0 V (Li / Li ⁺ , the same shall apply hereinafter) or less. It is preferable to become. That is, in the wound LIC according to the present invention, a positive electrode active material that can reversibly carry lithium ions and / or anions is used, while an active material that can reversibly carry lithium ions as a negative electrode active material. It is preferable to carry lithium ions on the negative electrode 12 and / or the positive electrode 11 in advance so that the potential of the positive electrode 11 and the negative electrode 12 becomes 2.0 V or less after the positive electrode 11 and the negative electrode 12 are short-circuited using a substance. .

In addition, in this invention, the electric potential of the positive electrode after short-circuiting a positive electrode and a negative electrode is 2.0V or less means the electric potential of the positive electrode calculated | required by either of the following two methods (A) or (B). The case where it becomes 2.0V or less.
(A) After being doped with lithium ions, the positive electrode terminal and the negative electrode terminal were allowed to stand for 12 hours or longer in a state where the positive electrode terminal and the negative electrode terminal were directly bonded to each other, then the short circuit was released and the positive electrode measured within 0.5 to 1.5 hours Potential.
(B) After discharging at constant current to 0 V over 12 hours with a charge / discharge tester, leaving the positive electrode terminal and the negative electrode terminal connected with a conducting wire for 12 hours or more, then releasing the short circuit, 0.5 ~ Positive electrode potential measured within 1.5 hours.

  In the present invention, the positive electrode potential of 2.0 V or less after the positive electrode 11 and the negative electrode 12 are short-circuited is not limited to immediately after being doped with lithium ions, but is charged, discharged or charged / discharged. The positive electrode potential after the short circuit is 2.0 V or less in any state, such as when a short circuit occurs after repeating the above.

In the present invention, the fact that the potential of the positive electrode becomes 2.0 V or less after the positive electrode and the negative electrode are short-circuited will be described in more detail.
As described above, activated carbon and carbon materials usually have a potential of about 3 V (Li / Li ⁺ ), and when a capacitor is formed using activated carbon for both the positive electrode and the negative electrode as an active material, any potential is used. Therefore, even if the positive electrode and the negative electrode are short-circuited, the potential of the positive electrode does not change and remains at about 3V. The same applies to so-called hybrid capacitors using activated carbon as the positive electrode active material and carbon materials such as graphite and non-graphitizable carbon used in lithium ion secondary batteries as the negative electrode active material. Since the potential is also about 3V, even if the positive electrode and the negative electrode are short-circuited, the potential of the positive electrode does not change and remains at about 3V. Therefore, although depending on the mass balance of the positive electrode and the negative electrode, since the potential of the negative electrode transitions to around 0 V when charged, the charge voltage can be increased, and thus a capacitor having a high voltage and a high energy density can be obtained. . In general, the upper limit of the charging voltage is determined to be a voltage at which the electrolyte does not decompose due to an increase in the positive electrode potential. Therefore, when the positive electrode potential is set as the upper limit, the charging voltage is increased by a value that decreases the negative electrode potential. Can be increased.

However, in the above-described hybrid capacitor in which the positive electrode potential is about 3 V at the time of short circuit, when the upper limit potential of the positive electrode is 4.0 V, for example, the positive electrode potential at the time of discharge is up to 3.0 V, The change is about 1.0 V, and the capacity of the positive electrode cannot be fully utilized. Furthermore, when lithium ions are inserted (charged) and desorbed (discharged) into the negative electrode, the initial charge / discharge efficiency is often low, and it is known that there are lithium ions that cannot be desorbed during discharge. . This has been explained that the surface of the negative electrode is consumed for the decomposition of the electrolyte solution or trapped in the structural defect portion of the carbon material, but in this case, compared to the charge / discharge efficiency of the positive electrode When the charge / discharge efficiency of the negative electrode is lowered and the positive electrode and the negative electrode are short-circuited after repeated charge / discharge, the positive electrode potential becomes higher than 3V and the utilization capacity further decreases. In other words, the positive electrode can be discharged from 4.0 V to 2.0 V. However, when the positive electrode can only be discharged from 4.0 V to 3.0 V, or only half of the available capacity is used. Although it is possible to obtain a high voltage, it is difficult to obtain a high capacity.
Therefore, in order to obtain not only a high voltage and a high energy density as a capacitor, but also a high capacity and a high energy density, it is necessary to improve the utilization capacity of the positive electrode.

  If the potential of the positive electrode after a short circuit between the positive electrode and the negative electrode is lower than 3.0 V, the use capacity increases and the capacity increases. In order to set the potential of the positive electrode to 2.0 V or less after a short circuit between the positive electrode and the negative electrode, not only the amount charged by charging / discharging of the capacitor but also lithium ions from a lithium ion supply source such as lithium metal to the negative electrode separately. It is preferable to charge. By supplying lithium ions from other than the positive electrode and the negative electrode, when the positive electrode and the negative electrode are short-circuited, the positive electrode, the negative electrode, and the lithium metal are in an equilibrium potential, so both the positive electrode potential and the negative electrode potential are 3.0 V. It becomes as follows. Further, the equilibrium potential decreases as the amount of lithium metal constituting the lithium ion supply source increases. If the negative electrode active material and the positive electrode active material change, the equilibrium potential also changes. Therefore, the negative electrode in consideration of the characteristics of the negative electrode active material and the positive electrode active material so that the positive electrode potential after the short circuit between the positive electrode and the negative electrode is 2.0 V or less. It is necessary to adjust the amount of lithium ions to be supported.

  In the wound LIC according to the present invention, as described above, the potential of the positive electrode 11 after the positive electrode 11 and the negative electrode 12 are short-circuited is 2.0 V or less. That is, lithium ions are supplied to the positive electrode and / or the negative electrode 12 from other than the negative electrode 12. The supply of lithium ions may be either one or both of the negative electrode 12 and the positive electrode 11. For example, when activated carbon is used as the positive electrode active material, the amount of lithium ions supported increases and the potential of the positive electrode 11 decreases. Since the lithium ion is consumed irreversibly and the capacity of the capacitor may be reduced, the amount of lithium ions supplied to the negative electrode 12 and the positive electrode 11 needs to be appropriately controlled so that the problem does not occur. It is. In any case, since the lithium ions previously supplied to the positive electrode 11 and / or the negative electrode 12 are supplied to the negative electrode 12 by charging the cell, the potential of the negative electrode 12 decreases.

Further, when the potential of the positive electrode 11 after the positive electrode 11 and the negative electrode 12 are short-circuited is higher than 2.0 V, it is obtained because the amount of lithium ions supplied to the positive electrode 11 and / or the negative electrode 12 is small. The energy density of the wound LIC is small. As the supply amount of lithium ions increases, the potential of the positive electrode 11 after the positive electrode 11 and the negative electrode 12 are short-circuited becomes lower and the energy density is improved. In order to obtain a high energy density, 2.0 V or less is preferable, and in order to obtain a higher energy density, 1.0 V (Li / Li ⁺ ) or less is preferable. That the potential of the positive electrode 11 becomes lower after the positive electrode 11 and the negative electrode 12 are short-circuited, in other words, the amount of lithium ions supplied to the negative electrode 12 increases by charging the wound LIC. That is, the capacitance of the negative electrode 12 increases and the potential change amount of the negative electrode 12 decreases. As a result, the potential change amount of the positive electrode 11 increases and the capacitance and capacity of the wound LIC increase. Thus, a high energy density can be obtained.

  Further, when the potential of the positive electrode 11 is less than 0.1 V, although depending on the positive electrode active material, problems such as gas generation and irreversible consumption of lithium ions occur. It becomes difficult. Moreover, when the electric potential of the positive electrode 11 becomes too low, it means that the mass of the negative electrode active material is excessive, and conversely, the energy density decreases. Therefore, generally, the potential of the positive electrode 11 is 0.1 V or higher, preferably 0.3 V or higher.

  In the present invention, the capacitance and the capacitance are defined as follows. The capacitance of the capacitor indicates the slope of the discharge curve of the capacitor, the unit is F (farad), and the capacitance per unit mass of the capacitor is the capacitance of the capacitor based on the mass of the positive electrode active material and the negative electrode active material. It is the value divided by the total mass of the substance, the unit is F / g, the capacitance of the positive electrode indicates the slope of the discharge curve of the positive electrode, the unit is F, and the capacitance per unit mass of the positive electrode The positive electrode capacitance is divided by the mass of the positive electrode active material, the unit is F / g, and the negative electrode capacitance is a value obtained by dividing the negative electrode capacitance by the mass of the negative electrode active material. The unit is F / g.

  Further, the capacitance of the capacitor is the difference between the discharge start voltage and the discharge end voltage of the capacitor, that is, the product of the voltage change amount and the capacitance of the capacitor. The unit is C (coulomb), but 1C is 1 Since this is the amount of charge when a current of 1 A flows per second, in this specification, it is converted into mAh. The capacity of the positive electrode is the product of the difference between the potential of the positive electrode at the start of discharge and the potential of the positive electrode at the end of discharge (amount of change in positive electrode potential) and the capacitance of the positive electrode, and the unit is C or mAh. The capacity is a product of the difference between the potential of the negative electrode at the start of discharge and the potential of the negative electrode at the end of discharge (amount of change in negative electrode potential) and the capacitance of the negative electrode, and the unit is C or mAh. The capacity of the capacitor matches the capacity of the positive electrode and the capacity of the negative electrode.

In the wound LIC according to the present invention, the capacitance per unit mass of the negative electrode active material is three times or more than the capacitance per unit weight of the positive electrode active material, and the mass of the positive electrode active material is negative electrode active material. The mass of the negative electrode is preferably larger than the mass of the material. For example, by appropriately controlling the filling amount (pre-doping amount) of lithium ions into the negative electrode 12 in consideration of the capacitance of the positive electrode, The electrostatic capacity can be set to three times or more the electrostatic capacity per unit mass of the positive electrode active material, and the mass of the positive electrode active material can be made larger than the mass of the negative electrode active material. Thereby, a capacitor having a higher voltage and a higher capacity than the conventional electric double layer capacitor can be obtained.
Further, when a negative electrode active material having a capacitance per unit weight larger than the capacitance per unit weight of the positive electrode active material is used, the mass of the negative electrode active material is changed without changing the potential change amount of the negative electrode 12. Since it can be reduced, the filling amount of the positive electrode active material is increased, and the capacitance and capacity of the wound LIC can be increased.
The mass of the positive electrode active material is preferably larger than the mass of the negative electrode active material, but more preferably 1.1 to 10 times the mass of the negative electrode active material. When the mass of the positive electrode active material is less than 1.1 times the mass of the negative electrode active material, the capacity difference becomes small, which is not preferable. On the other hand, when the mass of the positive electrode active material exceeds 10 times the mass of the negative electrode active material, the capacity may be reduced, and the thickness difference between the positive electrode 11 and the negative electrode 12 becomes too large. This is not preferable in the configuration of the rotary LIC.

As the first separator 13 and the second separator 14, it is possible to use a porous body having durability against an electrolytic solution, a positive electrode active material, or a negative electrode active material and having continuous air holes, and having low electrical conductivity.
As materials for the first separator 13 and the second separator 14, cellulose (paper), polyethylene, polypropylene, and other known materials can be used. Among these, cellulose (paper) is preferable in terms of durability and economy.
Although the thickness of the 1st separator 13 and the 2nd separator 14 is not specifically limited, Usually, about 20-50 micrometers is preferable.

As shown in FIG. 6, the lithium ion supply sources 15 and 16 are preferably pressure-bonded or stacked on metal current collectors (hereinafter referred to as “lithium electrode current collectors”) 15 a and 16 a. In such a configuration, the lithium electrode current collectors 15a and 16a can be electrically connected to, for example, the negative electrode terminal 18 through the lithium electrode terminals by providing the lithium electrode terminals.
The lithium electrode current collectors 15a and 16a have the same porous structure as that of the electrode current collector so that the lithium metal constituting the lithium ion supply sources 15 and 16 can be pressure-bonded easily and lithium ions can pass through if necessary. It is preferable to use one. Moreover, it is preferable to use what does not react with lithium ion supply sources 15 and 16, such as stainless steel, as the material of the lithium electrode current collectors 15a and 16a.
Further, when a conductive porous body such as a stainless mesh is used as the lithium electrode current collectors 15a and 16a, at least a part of the lithium metal constituting the lithium ion supply sources 15 and 16, particularly 80% by mass or more, It is preferable to be embedded in the holes of the lithium electrode current collectors 15a and 16a, so that even after lithium ions are supported on the negative electrode 12, gaps generated between the electrodes due to the disappearance of lithium metal are reduced and obtained. The reliability of the wound LIC can be maintained more reliably.
The thickness of the lithium electrode current collectors 15a and 16a is preferably about 10 to 200 μm.
Further, the thickness of the lithium metal to be pressure-bonded to the lithium electrode current collectors 15a and 16a is appropriately determined in consideration of the amount of lithium ions supported in advance on the negative electrode 12, but is usually preferably about 50 to 300 μm.

  The amount of lithium metal constituting the lithium ion supply sources 15 and 16 is such that the lithium ion is doped so that the potential of the positive electrode 11 after the positive electrode 11 and the negative electrode 12 are short-circuited is 2.0 V or less. Further, for example, lithium ions are supplied to the negative electrode 12 so that lithium ions can be doped as quickly and as balanced as possible from both the outer peripheral surface and the inner peripheral surface of the electrode winding unit 10. It is preferable to distribute the amount of lithium metal constituting the source 15 and the amount of lithium metal constituting the lithium ion supply source 16.

  The material of the negative electrode terminal 18 and the positive electrode terminal 17 is not particularly limited as long as it has conductivity, and various materials can be used, but the same material as that of the negative electrode current collector 12a and the positive electrode current collector 11a, respectively. A thing is preferable from points, such as connectivity and expansibility.

The material of the tape 25 is not particularly limited as long as it has durability against the electrolytic solution and does not adversely affect the obtained wound LIC, but the material of the first separator 13 and the second separator 14 is not limited. The same material is preferred.
Further, the tape 25 having a thickness of about 50 to 100 μm and a width of about 5 to 10 mm is preferable because the electrode winding unit 10 can be stably fixed and workability is improved.
In addition, the number of tapes 25 and the positions fixed by the tapes 25 are appropriately determined mainly depending on the dimensions of the electrode winding unit 10. Usually, when the number of the tapes 25 is 2 to 3, the electrode winding unit is used. 10 can be stably fixed.

As a material of the core rod 19, metal materials, such as stainless steel, copper, and nickel, can be used.
Further, the diameter of the core rod 19 can be appropriately set according to the diameter of the inner periphery of the electrode winding unit 10.

  The material of the outer container 20 is not particularly limited, and various materials generally used for batteries or capacitors can be used. For example, a metal material such as iron or aluminum, a plastic material, or a composite material obtained by laminating them is used. The outer container 20 may be a film type using a laminate film of aluminum and a polymer material such as nylon and polypropylene from the viewpoint of reducing the size and weight of the wound LIC. preferable. The shape of the outer container 20 is not particularly limited, and can be appropriately selected according to the use, such as a cylindrical shape or a rectangular shape. However, when the cylindrical electrode winding unit 10 is accommodated, a cylindrical one is used. When the flat cylindrical electrode winding unit 10 is accommodated, a rectangular shape is preferable.

As the electrolytic solution filled in the outer container 20, an aprotic organic solvent electrolyte solution of lithium salt is used.
As the lithium salt constituting the electrolyte, any lithium salt can be used as long as it is capable of transporting lithium ions, does not cause electrolysis even under high voltage, and lithium ions can exist stably. Specific examples thereof include LiClO ₄ , Examples include LiAsF ₆ , LiBF ₄ , LiPF ₆ , and Li (C ₂ F ₅ SO ₂ ) ₂ N.
Specific examples of the aprotic organic solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, acetonitrile, dimethoxyethane, tetrahydrofuran, dioxolane, methylene chloride, sulfolane and the like. These aprotic organic solvents can be used alone or in admixture of two or more.
The electrolytic solution is prepared by mixing the above electrolyte and solvent in a sufficiently dehydrated state, but the concentration of the electrolyte in the electrolytic solution is at least 0.1 in order to reduce the internal resistance due to the electrolytic solution. It is preferably at least mol / L, more preferably from 0.5 to 1.5 mol / L.

Such a wound LIC can be manufactured, for example, as follows.
First, a base layer 11c made of, for example, a carbon-based conductive material is formed on one surface of the positive electrode current collector 11a to close the holes P of the positive electrode current collector 11a, and then the positive electrode current collector 11a has a positive electrode on the surface of the base layer 11c. A positive electrode 11 is produced by applying a slurry containing an active material and a binder to form an electrode layer 11a, and an underlayer made of, for example, a carbon-based conductive material is formed on one surface of the negative electrode current collector 12a. By forming 12c, the hole P of the negative electrode current collector 12a is closed, and then a slurry containing a negative electrode active material and a binder is applied to the surface of the base layer 12c to form the electrode layer 12a. Thereby, the negative electrode 12 is produced. Then, the positive electrode terminal 17 and the negative electrode terminal 18 are fixedly connected to the positive electrode current collector 11a in the positive electrode 11 and the negative electrode current collector 12a in the negative electrode 12 by, for example, stitching.
Next, the negative electrode 12, the second separator 14, and the positive electrode 11 are stacked in this order on one surface of the first separator 13, whereby the electrode stack 10A is manufactured. Here, the positive electrode 11 and the negative electrode 12 are disposed such that the electrode layers 11 b and 12 b face each other with the second separator 14 interposed therebetween. And the electrode winding unit 10A is produced by winding the produced electrode stack 10A from one end of the electrode stack 10A so that the first separator 13 is on the inner side of the core rod 19, The electrode winding unit 10 is fixed by rolling the tape 25.
In the above, as shown in FIG. 7, the first separator 13 has an electrode on the other surface opposite to the one surface on which the negative electrode 12 is disposed on the one end side portion which is the innermost peripheral portion of the electrode winding unit 10. A lithium ion supply source 15 disposed on the inner peripheral surface of the innermost peripheral portion of the winding unit 10 is fixed by being crimped, and on the lithium ion supply source 15, as shown in FIG. A lithium electrode current collector 15a is fixed by pressure bonding. On the other hand, as shown in FIG. 9, the second separator 14 has lithium ions arranged on the outer peripheral surface of the electrode winding unit 10 on the surface of the other end side portion that is the outermost peripheral portion of the electrode winding unit 10. A supply source 16 is crimped and fixed, and a lithium electrode current collector 16a is crimped and fixed on the lithium ion supply source 16 as shown in FIG. In this way, the lithium ion supply sources 15 and 16 are arranged on the inner peripheral surface and the outer peripheral surface of the electrode winding unit 10, respectively.

  The electrode winding unit 10 thus produced is housed in the outer container 20 and filled with an electrolyte solution. Further, the positive electrode terminal 17 and the negative electrode terminal 18 in the electrode winding unit 10 are A wound type LIC is obtained by sealing the outer container 20 in a state where the outer container 20 is pulled out.

And in the wound type LIC produced in this way, since the outer container 20 is filled with an electrolyte solution capable of supplying lithium ions, when left for an appropriate period, the negative electrode 12 and / or the positive electrode The lithium ions released from the lithium ion supply sources 15 and 16 are doped into the negative electrode 12 and / or the positive electrode 11 by electrochemical contact between the lithium ion supply sources 15 and 16.
Thus, according to the present invention, the lithium ion supply source 15, the innermost surface of the electrode winding unit 10 provided with the lithium ion supply source 15, 16 is provided on the inner peripheral surface of the innermost peripheral portion. 16, there is an unoccupied region R that is not covered, and the proportion of the unoccupied region R is 10 to 10% of the outermost peripheral portion of the electrode winding unit 10 and / or the entire inner peripheral surface of the innermost peripheral portion. Since it is 70%, the electrolytic solution penetrates into the electrode winding unit 10 in a short time, and lithium ions are uniformly doped in the entire negative electrode 12 in a short time, so that high productivity is obtained. Further, the electrode stacking unit 10A is wound and lithium ion supply is performed by winding the electrode stack 10A in a state where the lithium ion supply sources 15 and 16 are arranged in advance on the first separator 13 and the second separator 14. Since the arrangement of the sources 15 and 16 can be performed in the same process, higher productivity can be obtained.

FIG. 11 is an explanatory cross-sectional view showing the configuration of an electrode winding unit in another example of a wound LIC according to the present invention.
The electrode winding unit 10 in the wound LIC of this example has an electrode stack in which a negative electrode 12, a second separator 14, and a positive electrode 11 are stacked in this order on one surface of a first separator 13. The separator 13 is wound in a flat cylindrical shape from one end of the electrode stack so that the innermost peripheral portion of the entire electrode winding unit 10 is the first separator 13. The innermost peripheral portion 13a is used. Further, the outermost peripheral portion of the positive electrode 11 is wound and covered by the outermost peripheral portion of the negative electrode 12, and the outermost peripheral portion of the negative electrode 12 is further covered by the outermost peripheral portion of the first separator 13 and the second separator 14. The outermost peripheral portion 14 a is wound and covered in this order, and thereby the outermost peripheral portion of the entire electrode winding unit 10 is the outermost peripheral portion 14 a of the second separator 14.
The inner circumferential surface of the innermost circumferential portion of the electrode winding unit 10 (the innermost circumferential portion 13a of the first separator 13), that is, the one surface on the one end side of the first separator 13 opposite to the one surface on which the negative electrode 12 is disposed. On the other surface, a plurality of rectangular film-like lithium metals which are respectively crimped to both surfaces of the lithium electrode current collector 15a extending in the width direction of the first separator 13 (direction perpendicular to the paper surface in FIG. 11). The lithium ion supply source 15 is arranged in a state of being separated from each other, and the lithium ion supply source 15 is not in direct contact with each of the positive electrode 11 and the negative electrode 12 by the first separator 13. Further, the inner peripheral surface of the outermost peripheral portion of the electrode winding unit 10 (the outermost peripheral portion 14a of the second separator 14), that is, the surface of the other end portion of the second separator 14 is respectively A lithium ion supply source 16 made of a plurality of rectangular film-like lithium metals, which is bonded to one surface of the lithium electrode current collector 16a and extends in the width direction (a direction perpendicular to the paper surface in FIG. 11), is disposed. The supply source 16 is not in direct contact with each of the positive electrode 11 and the negative electrode 12 by the second separator 14. In the illustrated example, two lithium ion supply sources 16 are disposed on one surface of the outer periphery of the electrode winding unit 10 and the other surface opposite thereto.
And the ratio of the unoccupied area | region R in the inner peripheral surface of the outermost peripheral part of the electrode winding unit 10 in which the lithium ion supply sources 15 and 16 were provided, and / or the inner peripheral surface of the innermost peripheral part is 10-70, respectively. %, Preferably 15 to 50%, more preferably 20 to 30%.

In the above, the configuration of the positive electrode 11, the negative electrode 12, and other members is basically the same as that of the wound LIC shown in FIG.
Moreover, the electrode winding unit 10 shown in FIG. 11 can be manufactured in the same manner as the electrode winding unit 10 of the wound LIC shown in FIG.

  The wound type LIC having such an electrode winding unit 10 accommodates the electrode winding unit 10 in an outer container, fills the outer container with an electrolyte, and further, a positive electrode in the electrode winding unit 10. The terminal 17 and the negative electrode terminal 18 are obtained by sealing the exterior container in a state where the terminal 17 and the negative electrode terminal 18 are pulled out of the exterior container.

And in the wound type LIC produced in this way, since the exterior container is filled with an electrolyte solution capable of supplying lithium ions, when left for an appropriate period, the negative electrode 12 and / or the positive electrode 11 The lithium ions released from the lithium ion supply sources 15 and 16 are doped into the negative electrode 12 and / or the positive electrode 11 by electrochemical contact between the lithium ion supply sources 15 and 16.
Thus, according to such a wound type LIC, the outermost peripheral portion of the electrode winding unit 10 provided with the lithium ion supply sources 15 and 16 and / or the unoccupied region on the inner peripheral surface of the innermost peripheral portion. Since the ratio of R is 10 to 70%, the electrolytic solution penetrates into the electrode winding unit 10 in a short time, and lithium ions are uniformly doped in the entire negative electrode 12 in a short time. Sex is obtained.
Further, the electrode stacking unit 10A is wound and lithium ion supply is performed by winding the electrode stack 10A in a state where the lithium ion supply sources 15 and 16 are arranged in advance on the first separator 13 and the second separator 14. Since the arrangement of the sources 15 and 16 can be performed in the same process, higher productivity can be obtained.

As mentioned above, although embodiment of this invention was described, this invention is not limited to these forms, A various change is possible.
For example, the present invention is not limited to a wound LIC, but can be suitably applied to a lithium ion secondary battery, and can also be applied to other wound storage power sources.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

<Example 1>
(1) Production of negative electrode:
A phenol resin molded plate having a thickness of 0.5 mm is placed in a siliconite electric furnace, heated to 500 ° C. at a rate of 50 ° C./hour in a nitrogen atmosphere, and further heated to 660 ° C. at a rate of 10 ° C./hour. The PAS plate was manufactured by heat treatment. The obtained PAS plate was pulverized with a disk mill to prepare a PAS powder. The H / C ratio of this PAS powder was 0.21.
Next, 100 parts by mass of the prepared PAS powder and 10 parts by mass of polyvinylidene fluoride powder were added to 80 parts by mass of N-methylpyrrolidone, and dissolved and dispersed to prepare a negative electrode slurry. This slurry for negative electrode was coated on the both sides of a negative electrode current collector made of copper expanded metal (manufactured by Nippon Metal Industry Co., Ltd.) having a thickness of 32 μm and a porosity of 50% by a die coater. 3 cm, the length of the uncoated part is intermittently applied and dried so as to be 10 cm, and the resulting coating film is pressed to form an electrode layer, thereby producing a negative electrode. .
The thickness of the obtained negative electrode (total thickness of the negative electrode current collector and the electrode layers formed on both surfaces thereof) was 77 μm.
The negative electrode is used as a working electrode, lithium metal is used as a counter electrode, and a reference electrode, and a capacitor is formed using an electrolytic solution in which LiPF ₆ is dissolved in propylene carbonate at a concentration of 1 mol / L. On the other hand, when lithium ions for 400 mAh / g were charged and the capacitance per unit weight of the negative electrode was determined, it was 661 F / g.

(2) Production of positive electrode:
By adding 100 parts by weight of activated carbon powder having a specific surface area of 1950 m ² / g, 10 parts by weight of acetylene black, 7 parts by weight of an acrylic binder, and 4 parts by weight of carboxymethyl cellulose to water and dispersing, A slurry was prepared.
On the other hand, non-aqueous carbon-based conductive paint (manufactured by Nippon Atchison Co., Ltd .: EB) -815) was intermittently coated with a die coater so that the length of the coated portion was 46.3 cm and the length of the uncoated portion was 10 cm, and dried to form a base layer. The total thickness of the positive electrode current collector and the underlayer formed on both surfaces thereof was 52 μm, and the holes of the positive electrode current collector were blocked by the underlayer.
Next, the prepared slurry for positive electrode is applied to both sides of the positive electrode current collector on which the underlayer is formed by a die coater so that the length of the coated portion is 46.3 cm and the length of the uncoated portion is 10 cm. By intermittently coating and drying, the resulting coating film was pressed to form an electrode layer, thereby producing a positive electrode.
The thickness of the obtained positive electrode (the total thickness of the positive electrode current collector and the base layer and electrode layer formed on both surfaces thereof) was 212 μm.
Further, this positive electrode is used as a working electrode, lithium metal as a counter electrode, and a reference electrode, and a capacitor is formed using an electrolytic solution in which LiPF ₆ is dissolved in propylene carbonate at a concentration of 1 mol / L. The capacitance per unit weight of the positive electrode was determined from the discharge time between 5 V and found to be 119 F / g.

(3) Production of electrode winding unit:
The manufactured negative electrode was cut to a size of 5.6 cm (width) × 49.3 cm (length) so as to include an uncoated portion of the negative electrode current collector at a position 10 mm from the end, and then made of nickel. The negative electrode terminal was placed on the uncoated part of the negative electrode current collector and connected by ultrasonic welding.
Further, the manufactured positive electrode was cut into a dimension of 5.4 cm (width) × 46.3 cm (length) so as to include an uncoated portion of the positive electrode current collector at a position 10 mm from the end portion, and was made of aluminum. The positive electrode terminal was placed on the uncoated part of the positive electrode current collector and connected by ultrasonic welding.
Moreover, the surface of the one end side part of the 1st separator used as the innermost peripheral part of the electrode winding unit obtained by preparing the 1st separator and 2nd separator which consist of a cellulose / rayon mixed nonwoven fabric each having a thickness of 35 μm A lithium ion source consisting of a lithium metal foil having a vertical and horizontal dimension of 5.4 cm × 0.9 cm and a thickness of 170 μm is arranged and fixed by crimping, and the vertical and horizontal dimensions are fixed on the lithium ion source. A lithium electrode current collector made of a copper expanded metal having a size of 7.4 cm × 0.9 cm, a thickness of 32 μm, and a porosity of 50% was placed and fixed by pressure bonding. On the other hand, the surface of the other end side portion of the second separator which is the outermost peripheral portion of the obtained electrode winding unit is made of a lithium metal foil having a vertical and horizontal dimension of 5.4 cm × 2.0 cm and a thickness of 170 μm. Two lithium ion sources are spaced apart at a distance of 0.5 cm and fixed by crimping, on these lithium ion sources, the vertical and horizontal dimensions are 5.4 cm × 2.0 cm, A lithium electrode current collector made of a copper expanded metal having a thickness of 32 μm and a porosity of 50% was placed and fixed by pressure bonding.
Then, the negative electrode, the second separator, and the positive electrode were stacked in this order on the surface of the first separator opposite to the surface to which the lithium ion supply source was pressure-bonded, thereby forming an electrode stack. Here, the positive electrode and the negative electrode were arranged so that the respective electrode layers face each other with the second separator interposed therebetween. This electrode stack is wound around one end of the electrode stack with a stainless steel core rod having a diameter of 3.5 mm so that the first separator is on the inside. A 5 mm cylindrical electrode winding unit was prepared and fixed by winding a tape on the electrode winding unit.
The ratio of the region (non-occupied region) not covered with the lithium ion supply source on the inner peripheral surface of the outermost peripheral portion and innermost peripheral portion of the electrode winding unit was 20%.
Moreover, since each lithium ion supply source was previously pressure-bonded to the first separator and the second separator, the electrode winding unit could be easily manufactured.

(4) Production of wound type LIC:
A bottomed cylindrical outer packaging material made of iron-nickel plating having an outer diameter of 18 mm and a height of 65 mm is prepared, and the produced electrode winding unit is housed inside the outer packaging material, and the electrode cage The negative electrode terminal of the rotating unit was resistance welded to the inner bottom of the outer container material, and then grooving was performed on the upper portion of the outer container material. Next, after attaching a polypropylene gasket to the top of the outer container material, the positive electrode terminal of the electrode winding unit was resistance-welded to the lid material. Then, 9 g of an electrolytic solution in which LiPF ₆ was dissolved in propylene carbonate at a concentration of 1 mol / L was injected into the exterior container material and vacuum impregnated, and the time until completion was 2 minutes. Thereafter, the outer container material was caulked and hermetically sealed in a state where the outer container material was covered with a lid material. In this way, a total of three cylindrical wound LICs were produced.

(5) Initial evaluation of wound type LIC:
The three wound LICs produced were allowed to stand for 7 days after being produced, and then one wound LIC was disassembled. As a result, it was confirmed that the lithium metal foil as the lithium ion supply source had disappeared. . From this, it is determined that the negative electrode has been doped with the expected amount of lithium ions after 7 days have passed since the production.

(6) Characteristic evaluation of wound type LIC Each of the two wound type LICs is charged with a constant current of 750 mA until the voltage of the capacitor reaches 3.8 V, and then a constant voltage of 3.8 V is applied. Constant current-constant voltage charging was performed for 0.5 hour. Next, the capacitor was discharged with a constant current of 750 mA until the voltage of the capacitor reached 2.2V. This operation was repeated as one cycle, and the capacity, energy density, and internal resistance of the capacitor in the discharge at the tenth cycle were measured, and the average value for the two wound LICs was calculated. The results are shown in Table 1 below.

  As is clear from the above results, according to Example 1, the electrode winding unit can be easily manufactured, the electrolyte solution can be permeated in a short time, and lithium ions can be uniformly doped in the entire negative electrode in a short time. Therefore, it was confirmed that a wound type LIC with high productivity, high capacitance and energy density, and low internal resistance was obtained.

<Comparative example 1>
As a lithium ion supply source disposed on the inner peripheral surface of the electrode winding unit, one lithium metal foil having a vertical and horizontal dimension of 5.4 cm × 1.0 cm and a thickness of 135 μm is used. An electrode winding unit is manufactured in the same manner as in Example 1 except that one lithium metal foil having a vertical and horizontal dimension of 5.4 cm × 5.0 cm and a thickness of 135 μm is used as a lithium ion supply source. Three wound type LICs were produced.
In the above, the ratio of the area | region (unoccupied area | region) which is not covered with the lithium ion supply source in the inner peripheral surface of the outermost periphery part of an electrode winding unit and an innermost periphery part was 0%, respectively.
Further, in the production of the wound type LIC, when the electrolyte was injected and vacuum impregnated, the time until completion was 4 minutes.
When the manufactured wound type LIC was initially evaluated in the same manner as in Example 1, it was confirmed that the lithium metal foil remained.
Further, the fabricated wound LIC was evaluated for characteristics in the same manner as in Example 1. The results are shown in Table 2 below.

  From the above results, in Comparative Example 1, since the proportion of the non-occupied region is 0%, it takes a longer time for the electrolyte to penetrate than in Example 1, and lithium ions are dispersed throughout the negative electrode. It took a long time to dope uniformly.

<Comparative example 2>
In the same manner as in Example 1, a negative electrode and a positive electrode were produced.
The manufactured negative electrode was cut to a size of 5.6 cm (width) × 49.3 cm (length) so as to include an uncoated portion of the negative electrode current collector at a position 10 mm from the end, and then made of nickel. The negative electrode terminal was placed on the uncoated part of the negative electrode current collector and connected by ultrasonic welding.
Further, the manufactured positive electrode was cut into a dimension of 5.4 cm (width) × 46.3 cm (length) so as to include an uncoated portion of the positive electrode current collector at a position 10 mm from the end portion, and was made of aluminum. The positive electrode terminal was placed on the uncoated part of the positive electrode current collector and connected by ultrasonic welding.
Then, by preparing a first separator and a second separator made of cellulose / rayon mixed nonwoven fabric each having a thickness of 35 μm, and stacking the first separator, the negative electrode, the second separator and the positive electrode in this order, An electrode stack was constructed. Here, the positive electrode and the negative electrode were arranged so that the respective electrode layers face each other with the second separator interposed therebetween. The electrode stack is wound from one end of the electrode stack with an aluminum core rod having a diameter of 3.5 mm so that the first separator is on the inner side, whereby an inner diameter of 3.5 mm and an outer diameter of 15. A 5 mm electrode winding unit was prepared, and fixed by winding a tape on the electrode winding unit.
Next, from a copper expanded metal having a vertical and horizontal dimension of 5.4 cm × 5.0 cm and a thickness of 32 μm to a lithium ion source made of a lithium metal foil having a vertical and horizontal dimension of 5.4 cm × 5.0 cm and a thickness of 134 μm. The lithium electrode current collector was crimped, and the lithium ion supply source to which the lithium electrode current collector was crimped was disposed so as to be in contact with the outer peripheral surface of the electrode winding unit. In addition, a lithium ion supply source made of a lithium metal foil having a vertical and horizontal dimension of 5.4 cm × 1.0 cm and a thickness of 134 μm is applied to a copper expanded metal having a vertical and horizontal dimension of 5.4 cm × 1.0 cm and a thickness of 32 μm. The lithium electrode current collector was crimped, and the lithium ion supply source to which the lithium electrode current collector was crimped was disposed so as to be in contact with the inner peripheral surface of the electrode winding unit.
The ratio of the region (non-occupied region) not covered with the lithium ion supply source on the inner peripheral surface and the outer peripheral surface of the electrode winding unit was 0%.
In the above, it took a long time to arrange the lithium ion supply source.

A bottomed cylindrical outer packaging material made of iron-nickel plating having an outer diameter of 18 mm and a height of 65 mm is prepared, and the produced electrode winding unit is housed inside the outer packaging material, and the electrode cage The negative electrode terminal of the rotating unit was resistance welded to the inner bottom of the outer container material, and then grooving was performed on the upper portion of the outer container material. Next, after attaching a polypropylene gasket to the top of the outer container material, the positive electrode terminal of the electrode winding unit was resistance-welded to the lid material. Then, 9 g of an electrolytic solution in which LiPF ₆ was dissolved in propylene carbonate at a concentration of 1 mol / L was injected into the exterior container material and vacuum impregnated, and the time to completion was 3 minutes. Thereafter, the outer container material was caulked and hermetically sealed in a state where the outer container material was covered with a lid material. In this way, a total of three cylindrical wound LICs were produced.
When the manufactured wound type LIC was initially evaluated in the same manner as in Example 1, it was confirmed that the lithium metal foil remained. After assembling the disassembled wound LIC and leaving it to stand for 2 days (9 days in total), the wound LIC was disassembled again, and it was confirmed that the lithium metal foil as the lithium ion supply source had disappeared. . From this, it is judged that the intended amount of lithium ions has been doped into the negative electrode after 9 days from the production. Further, the fabricated wound LIC was evaluated for characteristics in the same manner as in Example 1. The results are shown in Table 3 below.

  From the above results, in Comparative Example 2, since the proportion of the non-occupied region is 0%, it takes a longer time for the electrolyte to penetrate than in Example 1, and lithium ions are dispersed throughout the negative electrode. It took a long time to dope uniformly. Moreover, the internal resistance of the obtained wound type LIC was high. This is considered because the contact pressure between the electrode winding unit and the lithium ion supply source was insufficient because the lithium ion supply source was arranged after the electrode winding unit was manufactured.

It is sectional drawing for description which shows the structure in an example of the winding type | mold LIC which concerns on this invention. It is sectional drawing for description which shows the structure of an electrode stack. It is explanatory drawing which shows the electrode winding unit in the winding type | mold LIC shown in FIG. It is an explanatory top view shown in the state where the electrode in the electrode winding unit was developed. It is explanatory drawing which expands and shows the AA cross section of the electrode shown in FIG. It is sectional drawing for description which shows a lithium ion supply source and a lithium electrode electrical power collector. It is explanatory drawing which shows the state by which the lithium ion supply source was crimped | bonded to the other surface in the one end side part of a 1st separator. It is explanatory drawing which shows the state by which the lithium electrode electrical power collector was crimped | bonded to the lithium ion supply source crimped | bonded to the 1st separator. It is explanatory drawing which shows the state by which the lithium ion supply source was crimped | bonded to the surface in the surplus part of a 2nd separator. It is explanatory drawing which shows the state by which the lithium electrode electrical power collector was crimped | bonded to the lithium ion supply source crimped | bonded to the 2nd separator. It is sectional drawing for description which shows the structure of the electrode winding unit in the other example of the winding type | mold LIC which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electrode winding unit 10A Electrode stack 11 Positive electrode 11a Positive electrode collector 11b Electrode layer 11c Underlayer 12 Negative electrode 12a Negative electrode collector 12b Electrode layer 12c Underlayer 13 First separator 13a Innermost peripheral portion 14 Second separator 14a Outermost peripheral portion 15, 16 Lithium ion supply source 15a, 16a Lithium electrode current collector 17 Positive electrode terminal 18 Negative electrode terminal 19 Core rod 20 Exterior container 25 Tape P Hole R Unoccupied region

Claims (8)

A belt-like positive electrode in which an electrode layer containing a positive electrode active material capable of reversibly supporting lithium ions and / or anions is formed on at least one surface of a current collector having holes penetrating the front and back surfaces; A belt-like negative electrode in which an electrode layer containing a negative electrode active material capable of reversibly supporting lithium ions is formed on at least one surface of a current collector having a through-hole, and the positive electrode and the negative electrode are separators A cylindrical electrode winding unit in which the electrode stack is stacked from one end and the outermost peripheral part and / or the innermost peripheral part is the separator,
A lithium ion source provided on the inner peripheral surface of the outermost peripheral portion and / or the inner peripheral surface of the innermost peripheral portion of the electrode winding unit; and
Comprising an electrolyte comprising an aprotic organic solvent electrolyte solution of a lithium salt,
A wound-type storage power source in which lithium ions are doped into the negative electrode and / or the positive electrode by electrochemical contact between the negative electrode and / or the positive electrode and the lithium ion supply source,
The ratio of the area not covered by the lithium ion supply source on the inner peripheral surface of the outermost peripheral portion and / or the outer peripheral surface of the innermost peripheral portion of the electrode winding unit provided with the lithium ion supply source is 10 respectively. A wound-type storage power source characterized by being -70%.   The wound-type storage power source according to claim 1, wherein the lithium ion supply source is provided so as not to contact the positive electrode and the negative electrode by a separator.   The wound-type storage power source according to claim 1 or 2, wherein the lithium ion supply source is crimped or stacked on a metal current collector.   4. The wound-type storage power source according to claim 3, wherein the metal current collector on which the lithium ion supply source is crimped or stacked is made of a porous foil.   The electrode stack is formed by stacking the first separator, the negative electrode, the second separator, and the positive electrode in this order, and a surface opposite to the surface on which the negative electrode is disposed on the one end side portion of the first separator. In addition, a lithium supply source provided on the inner peripheral surface of the innermost peripheral portion of the electrode winding unit is disposed, and the electrode winding unit is configured by winding the electrode stack from one end thereof. The wound-type storage power source according to any one of claims 1 to 4.   In the electrode winding unit, the outermost peripheral part of the positive electrode is covered with the outermost peripheral part of the negative electrode through the separator, and the outermost peripheral part of the negative electrode is covered with the outermost peripheral part of the separator. The wound-type storage power source according to any one of claims 1 to 5, wherein a lithium supply source is provided on an inner peripheral surface of the portion.   The wound-type storage power source according to any one of claims 1 to 6, which is a lithium ion capacitor.   The wound storage power source according to any one of claims 1 to 6, which is a lithium ion secondary battery.

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