JP5271860B2 - Accumulator - Google Patents

Description

  The present invention relates to a storage power source such as a lithium ion secondary battery and a lithium ion capacitor.

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 is a combination of the storage principles of lithium ion secondary batteries and electric double layer capacitors, has recently 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).
As such an organic electrolyte capacitor, a wound type having an electrode unit in which an electrode stack in which a positive electrode and a negative electrode are stacked through a separator capable of impregnating an electrolyte is wound from one end thereof, and a plurality of positive electrodes In addition, in these capacitors, a separator of an electrode unit is known which has an electrode unit composed of an electrode stack in which a plurality of negative electrodes are alternately stacked via a separator that can be impregnated with an electrolyte. The entire electrode unit is fixed by a tape having a pressure-sensitive adhesive layer.

Japanese Patent Laid-Open No. 8-1007048

  However, in such a capacitor, the adhesive layer of the tape provided on the separator absorbs the electrolytic solution, and the electrolytic solution impregnated in the separator is remarkably reduced at the portion in contact with the adhesive layer in the separator. Therefore, when lithium ions are doped in advance from the lithium ion supply source to the negative electrode, in the lithium ion supply source, the ionization of the portion in contact with the portion where the electrolytic solution in the separator is reduced is slower than the other portions. Since unevenness occurs in the supply rate of lithium ions, it takes a long time to uniformly dope lithium ions throughout the negative electrode, resulting in a problem that high productivity cannot be obtained.

  The present invention has been made based on the above circumstances, and its purpose is to prevent unevenness in the supply rate of lithium ions when doping lithium ions from a lithium ion supply source to a negative electrode. The object is to provide a storage power source that is suppressed and has high productivity.

The accumulator of the present invention is a positive electrode in which 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 holes penetrating the front and back surfaces, the positive electrode and the positive electrode An electrode unit comprising an electrode stack in which negative electrodes are stacked via separators;
A lithium ion source provided in contact with one surface of the separator; and
Comprising an electrolyte comprising an aprotic organic solvent electrolyte solution of a lithium salt,
A 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 other surface of the separator is provided with a tape that fixes the electrode unit and has an adhesive layer formed on one surface so as to overlap the lithium ion supply source via the separator, and / or A plurality of holes penetrating in the thickness direction of the pressure-sensitive adhesive layer are formed ,
The plurality of holes formed in the pressure-sensitive adhesive layer have a pitch of 1 to 5 mm and a diameter of 1 to 5 mm .

In the 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 a 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 source is crimped or stacked is made of a porous foil. Further preferred.

In the storage power source of the present invention, the electrode unit is configured by winding the electrode stack from one end thereof, and the lithium ion supply source is provided at one end side portion and / or the other end side portion of the separator. It may be done.
In such a storage power source, the electrode stack is formed by stacking a first separator, a negative electrode, a second separator, and a positive electrode in this order, and a negative electrode is formed on one end side portion of the first separator. The lithium ion supply source may be disposed on a surface opposite to the surface on which the lithium ion supply source is disposed, and the electrode stack may be wound from one end so that the lithium ion supply source is on the inner side.

In the storage power source of the present invention, the electrode unit includes an electrode stack in which a plurality of the positive electrodes and a plurality of the negative electrodes are alternately stacked via separators, and the lithium ion supply source includes the electrode stack. It may be provided in the separator arranged first.
In such a storage power source, a negative electrode may be disposed on the separator disposed first in the electrode stack.

  Moreover, the storage power supply of this invention is suitable as a lithium ion capacitor.

According to the storage power source of the present invention, the tape provided in the separator is formed with a plurality of holes penetrating in the thickness direction of the tape and / or the pressure-sensitive adhesive layer, and the plurality of holes have a pitch thereof. Is 1 to 5 mm, and the diameter is 1 to 5 mm, it is possible to prevent or suppress a decrease in the electrolyte solution impregnated in the separator in the portion in contact with the pressure-sensitive adhesive layer in the separator. When lithium ions are doped in advance from the lithium ion source to the negative electrode, unevenness in the supply rate of lithium ions is prevented or suppressed, so that lithium ions can be uniformly doped throughout the negative electrode in a short time. Therefore, high productivity can be obtained.

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 a side view of the electrode winding unit in the winding type 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 a top view of the tape in the wound type LIC shown in FIG. It is explanatory drawing which expands and shows the YY cross section of the tape shown in FIG. It is a side view of the electrode winding unit in the other example of the winding type LIC concerning the present invention. It is a side view of the electrode winding unit in the further another example of the winding type LIC concerning the present invention. It is sectional drawing for description which shows the modification of a tape.

Hereinafter, a case where the storage power source of the present invention is implemented as a wound lithium ion capacitor (hereinafter also referred to as “winding 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 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. It is configured to be wound around a core rod 19 from one end 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, whereby the inner peripheral surface of the electrode winding unit 10 is formed by the first separator 13. The negative electrode 12 and the second separator 14 are longer than the positive electrode 11 and the first separator 13, and the outermost peripheral portion of the positive electrode 11 is wound around the outermost peripheral portion of the negative electrode 12 and the second separator 14. Thus, the outer peripheral surface of the electrode winding unit 10 is formed by 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.

  On the inner peripheral surface of the electrode winding unit 10, that is, on the other surface opposite to the one surface on which the negative electrode 12 is disposed on the one end side portion of the first separator 13, a lithium ion supply source 15 made of film-like lithium metal is provided. The lithium ion supply source 15 is arranged in a state where it is crimped to the first separator 13 and is not in direct contact with each of the positive electrode 11 and the negative electrode 12 by the first separator 13. Has been. Further, a lithium ion supply source 16 made of a film-like lithium metal is crimped to the second separator 14 on the surface of the second separator 14 while being spaced apart from the outer end portion 11E of the positive electrode 11 in the circumferential direction. The lithium ion 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, a lithium ion supply source 16 is disposed at a portion of the second separator 14 wound so as to cover the outermost peripheral portion of the negative electrode 12, and the second separator 14 is disposed at the outer end of the lithium ion supply source 16. The surplus portion 14a is further wound from the portion 16E by one or more rounds, and the lithium ion supply source 16 is in contact with the inner surface of the surplus portion 14a.

As shown in FIG. 3, the outer circumferential surface of the electrode winding unit 10, that is, the outer surface of the surplus portion 14 a of the second separator 14 is positioned so as to overlap the lithium ion supply source 16 through the second separator 14. In the state where the strip-shaped tape 25 for fixing the electrode winding unit 10 overlaps the lithium ion supply source 16 via the second separator 14, the width direction along the other end 14 </ b> E of the second separator 14. (The direction perpendicular to the paper surface in FIG. 1) is provided so that the work of housing the electrode winding unit 10 in the outer container 20 is facilitated, 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 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 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 H 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 H 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 the electrodes from the sources 15 and 16 through the holes H of the electrode current collector, the negative electrode 12 and / or the positive electrode 11 can be doped with lithium ions.

In the present invention, at least a part of the holes H in the electrode current collector are closed with a conductive material that does not easily fall off, and in this state, the electrode layers 11b and 12b 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), a higher output density can be obtained.
The shape and number of holes H 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 organic semiconductor (hereinafter referred to as “PAS”) having a polyacene skeleton structure of 0.50 to 0.05.

  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 12b 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 H 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 H is blocked by the base layer 12c, and a smooth coating surface is formed. 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 12b 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 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 (Li / Li ⁺ , the same shall apply hereinafter) or less. Is preferred. 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 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 accordingly. 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. Also, 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 11 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.

As the first separator 13 and the second separator 14, a porous body that has durability against an electrolytic solution, a positive electrode active material, or a negative electrode active material and has continuous air holes that can be impregnated with the electrolytic solution, etc. Can be used.
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, and the materials of the negative electrode current collector 12a and the positive electrode current collector 11a are respectively The same thing is preferable from points, such as connectivity and expansibility.

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.

FIG. 7 is a plan view of the tape 25 in the wound LIC shown in FIG. 1, and FIG. 8 is an explanatory view showing an enlarged YY section of the tape shown in FIG.
The tape 25 has an adhesive layer 27 formed on one surface, and the tape 25 has a plurality of holes 26 penetrating the entire tape 25 including the adhesive layer 27 in the thickness direction.

The material of the base 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 first separator 13 and the second separator The same material as the separator 14 is preferable.
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.
Moreover, it is preferable that the area of the arrangement | positioning area | region of the tape 25 is 1-30% of the area of the outermost peripheral surface of the electrode winding unit 10, More preferably, it is 5-30%, More preferably, it is 5-25%. .
Further, the length of the tape 25 may be equal to the width of the second separator 14 or may be smaller than the width of the second separator 14.

  The pitch P of the holes 26 formed in the tape 25 (distance between the centers of adjacent holes 26) P is preferably 1 to 5 mm, more preferably 2 to 5 mm, and still more preferably 2.5 to 4 mm. When the pitch P of the holes 26 is less than 1 mm, the adhesion to the second separator 14 tends to be low, and the tape 25 may be peeled off from the second separator 14. On the other hand, when the pitch P of the holes 26 exceeds 5 mm, the absorption of the electrolytic solution into the tape 25 increases, so that the electrolytic solution impregnated in the second separator 14 is easily depleted. Unevenness occurs in speed, and productivity is reduced.

  Moreover, it is preferable that the diameter D of the hole 26 formed in the tape 25 is 1-5 mm, More preferably, it is 2-5 mm, More preferably, it is 2.5-4 mm. When the diameter D of the hole 26 is less than 1 mm, the absorption of the electrolytic solution into the tape 25 increases, so that the electrolytic solution impregnated in the second separator 14 is easily depleted. As a result, unevenness occurs and productivity is reduced. On the other hand, when the diameter D of the hole 26 exceeds 5 mm, the adhesion to the second separator 14 tends to be low, and the tape 25 may be peeled off from the second separator 14.

  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.

The exterior container 20 is filled with an electrolytic solution made of an aprotic organic solvent electrolyte solution of a lithium salt.
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.

In the wound type LIC, the electrode winding unit 10 is accommodated in the outer container 20, and the outer container 20 is filled with an electrolytic solution. Further, the positive electrode terminal 17 and the negative electrode terminal 18 in the electrode winding unit 10. Can be obtained by sealing the outer container 20 in a state where the outer container 20 is pulled out of the outer container 20.
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.
Further, the electrode stacking unit 10 is manufactured and the lithium ion is supplied 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.

  According to such a wound LIC, the tape 25 provided in the second separator 14 is formed with a plurality of holes 26 penetrating the adhesive layer 27 in the thickness direction. 14, it is possible to prevent or suppress the decrease in the electrolyte solution impregnated in the second separator 14 at the portion in contact with the pressure-sensitive adhesive layer 27. When doping is performed, unevenness in the supply rate of lithium ions is prevented or suppressed, so that lithium ions can be uniformly doped in the entire negative electrode 12 in a short time, and thus high productivity can be obtained. .

As mentioned above, although embodiment of the storage power supply of this invention was described, this invention is not limited to said form, A various change is possible.
(1) The shape and arrangement position of the tape 25 are not limited to those shown in FIG.
For example, as shown in FIG. 9, a plurality of rectangular tapes 25 may be provided along the other end portion 14 </ b> E of the second separator 14 so as to be spaced apart from each other in the width direction. According to such a configuration, since the area of the arrangement region of the tape 25 can be reduced, the absorption of the electrolytic solution by the adhesive layer 27 of the tape 25 is reduced, and as a result, the supply rate of lithium ions is further uneven. In addition, the productivity is further improved and the consumption of the tape material is reduced, so that the cost can be reduced.
Further, as shown in FIG. 10, a plurality of strip-shaped tapes 25 may be provided so as to extend in the circumferential direction of the second separator 14 while being separated from each other in the width direction of the second separator 14. The tape 25 may be provided so as to run over one turn or more of the electrode winding unit 10 or may be provided so as to run less than one turn of the electrode winding unit 10.
As shown in FIG. 11, the hole 26 of the tape 25 may be formed so as to penetrate only the pressure-sensitive adhesive layer 27.
(2) The storage power source of the present invention may be of a laminated type having an electrode unit composed of an electrode stack in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked via separators. The lithium ion source can be provided on the first placed separator in the electrode stack. In such a configuration, it is preferable that the negative electrode is disposed on the separator disposed first.
(3) The storage power source of the present invention is not limited to the LIC, but can be suitably applied to a wound or stacked lithium ion secondary battery, and other stacked or wound storages. It can also be applied to power supplies.

DESCRIPTION OF SYMBOLS 10 Electrode winding unit 10A Electrode stack 11 Positive electrode 11a Positive electrode current collector 11b Electrode layer 11c Underlayer 11E Positive electrode outer end 12 Negative electrode 12a Negative electrode current collector 12b Electrode layer 12c Underlayer 13 First separator 13a Innermost circumference Portion 14 Second separator 14a Surplus portion 14E Other end portions 15 and 16 of second separator Lithium ion supply source 15a and 16a Lithium electrode current collector 16E Outer end portion of lithium ion supply source 17 Positive electrode terminal 18 Negative electrode terminal 19 core Bar 20 Exterior container 25 Tape 26 Hole 27 Adhesive layer H Hole

Claims (9)

A 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, and penetrates the front and back surfaces. 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 pores, and the positive electrode and the negative electrode are stacked via a separator. An electrode unit composed of stacked electrode stacks,
A lithium ion source provided in contact with one surface of the separator; and
Comprising an electrolyte comprising an aprotic organic solvent electrolyte solution of a lithium salt,
A 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 other surface of the separator is provided with a tape that fixes the electrode unit and has an adhesive layer formed on one surface so as to overlap the lithium ion supply source via the separator, and / or A plurality of holes penetrating in the thickness direction of the pressure-sensitive adhesive layer are formed ,
The plurality of holes formed in the pressure-sensitive adhesive layer have a pitch of 1 to 5 mm and a diameter of 1 to 5 mm . The storage battery 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 the separator. The storage battery according to claim 1 or 2, wherein the lithium ion supply source is crimped or stacked on a metal current collector. The storage battery 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 unit is configured by winding the electrode stack from one end thereof, and the lithium ion supply source is provided at one end side portion and / or the other end side portion of the separator. The storage power supply according to any one of claims 1 to 4. The electrode stack is formed by stacking a first separator, a negative electrode, a second separator, and a positive electrode in this order. One end side portion of the first separator is opposite to the surface on which the negative electrode is disposed. 6. The storage power source according to claim 5, wherein the lithium ion supply source is disposed on a surface, and the electrode stack is wound from one end so that the lithium ion supply source is on the inside. The electrode unit is composed of an electrode stack in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked via separators, and the lithium ion supply source is a separator disposed first in the electrode stack. The storage power supply according to any one of claims 1 to 4, wherein the storage power supply is provided. The accumulator according to claim 7, wherein a negative electrode is disposed on a separator disposed first in the electrode stack. The storage power supply according to any one of claims 1 to 8, which is a lithium ion capacitor.

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