JP2016143711A - Method of manufacturing electrode, power storage device and device for making active material of electrode occlude lithium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrode, where occlusion of lithium to an electrode active material progresses uniformly at a low cost, and to provide a power storage device and a device.SOLUTION: A method of manufacturing an electrode includes (A) a step for reducing the pressure in a chamber housing a collector in which a layer containing an active material (hereinafter, referred to (active material layer)) is formed, and a lithium supply source, (B) a step for supplying an organic solvent containing lithium ions into the chamber subjected to pressure reduction, and (C) a step for making the active material occlude lithium. Consequently, an electrode where the entire active material is doped uniformly with lithium can be obtained, and it is very useful in the manufacture of the electrode of a battery or a capacitor, such as a lithium ion secondary battery, an air battery, a lithium ion capacitor, and the like.SELECTED DRAWING: None

Description

  The present invention relates to an electrode manufacturing method, an electricity storage device, and an apparatus for occluding lithium in an active material of an electrode, and more specifically, suitable for a battery or capacitor such as a lithium ion secondary battery, an air battery, or a lithium ion capacitor. The present invention relates to an electrode manufacturing method to be used, an electricity storage device including an electrode manufactured by the manufacturing method, and an apparatus for inserting lithium into an active material of the electrode.

  2. Description of the Related Art In recent years, progress in downsizing and weight reduction of electronic devices has been remarkable, and accordingly, demands for downsizing and weight reduction of batteries used as power sources for driving the electronic devices are further increased. In order to satisfy such demands for reduction in size and weight, nonaqueous electrolyte secondary batteries represented by lithium ion secondary batteries have been developed as power storage devices. Moreover, a lithium ion capacitor is known as an electricity storage device corresponding to an application that requires high energy density characteristics and high output characteristics.

  In such an electricity storage device, a process (generally referred to as pre-doping) in which lithium is previously occluded in an electrode active material is employed for various purposes. For example, in a lithium ion capacitor, pre-doping is performed in order to lower the negative electrode potential and increase the energy density, but a method of pre-doping a negative electrode active material in a cell using a current collector having a through hole has become mainstream. (For example, refer to Patent Document 1). In addition, in a lithium ion secondary battery, pre-doping is performed to reduce the irreversible capacity of the negative electrode. In addition to the above method, a method of pre-doping the negative electrode active material before assembling the battery is adopted (for example, (See Patent Documents 2 and 3).

JP 2007-67105 A JP 7-235330 A Japanese Patent Laid-Open No. 9-293499

  However, in the method using a current collector having a through hole, there is a problem that the manufacturing cost becomes very high because it is necessary to provide a regular and fine through hole in the current collector. Further, in the method proposed in Patent Document 3, it is not necessary to use a current collector having a through-hole. However, since the electrolytic solution does not easily penetrate into the pores of the electrode active material, the occlusion of lithium is an electrode active material. There is a problem that it does not proceed uniformly in the plane of the layer and in the thickness direction.

  Therefore, an object of the present invention is to provide an electrode manufacturing method, an electricity storage device, and an apparatus that are low in cost and in which occlusion of lithium into the electrode active material is uniform.

In view of this situation, the present inventors have conducted intensive research and found that the above-mentioned problems can be solved by adopting a specific process, and the present invention has been completed.
That is, in the first aspect of the present invention, (A) the pressure in the chamber containing the current collector and the lithium supply source in which the layer containing the active material (hereinafter also referred to as “active material layer”) is formed is reduced. Provided is a method for producing an electrode, comprising: (B) supplying an organic solvent containing lithium ions into the decompressed chamber; and (C) occluding lithium in the active material.

According to a second aspect of the present invention, there is provided an electricity storage device comprising a negative electrode, a positive electrode, and an electrolyte produced by the production method according to the first aspect of the present invention.
Furthermore, in the third aspect of the present invention, (1) a current chamber in which a layer containing an active material is formed and a chamber containing a lithium supply source, (2) a decompression means for decompressing the inside of the chamber, and (3 An apparatus for occluding lithium in an active material of an electrode, comprising supply means for supplying an organic solvent containing lithium ions into the chamber.

  By using the manufacturing method and apparatus of the present invention, an electrode in which lithium is uniformly doped in the entire active material can be obtained. Therefore, the production method and apparatus of the present invention are extremely useful for the production of a battery such as a lithium ion secondary battery, an air battery, or a lithium ion capacitor, or an electrode of a capacitor. In addition, by using the electrode manufactured by the manufacturing method of the present invention, it is possible to obtain a battery and a capacitor including an electrode in which lithium is uniformly doped in the entire active material.

It is a model diagram explaining the whole structure of the apparatus of this invention. It is an exploded view explaining the structure of the chamber etc. of FIG. It is a schematic diagram explaining the structure of the chamber of FIG. 1, and a preliminary | backup chamber. 4A is an exploded view illustrating the configuration of the holding portion, FIG. 4B is a schematic diagram illustrating the configuration of the electrode precursor, and FIG. 4C is a diagram of the lithium electrode. It is a schematic diagram explaining a structure. It is a block diagram explaining the structure of the control part of FIG.

Hereinafter, the present invention will be described in detail.
[Method for producing electrode]
In the production method of the present invention, the organic solvent containing lithium ions penetrates evenly into the pores of the active material by contacting with an organic solvent containing lithium ions in a state where the system containing the active material layer is decompressed. Therefore, it is considered that a high-quality electrode containing an active material in which lithium is uniformly occluded can be obtained.
(A) Process The electrical power collector in which the active material layer was formed is normally manufactured by preparing the slurry containing an active material, a binder, etc., apply | coating this on a electrical power collector, and making it dry. The active material is not particularly limited as long as it is an electrode active material used for an electrode utilizing insertion / extraction of lithium ions, and may be a negative electrode active material or a positive electrode active material.

  Examples of the negative electrode active material include carbon materials such as graphite, graphitizable carbon, non-graphitizable carbon, and composite carbon materials in which graphite particles are coated with a carbide of pitch or resin; alloying with lithium such as Si and Sn is possible. Or a metal containing a semimetal or an oxide thereof. Specific examples of the carbon material include carbon materials described in JP2013-258392A. Specific examples of a material containing a metal, a semimetal, or an oxide thereof that can be alloyed with lithium include materials described in JP-A-2005-123175 and JP-A-2006-107795.

  Examples of the positive electrode active material include lithium transition metal composite oxides such as lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide. Note that the production method of the present invention can compensate for lithium deficiency in the positive electrode active material.

  Both positive and negative electrode active materials can be used alone or in admixture of two or more. The production method of the present invention is suitable for occluding lithium in the negative electrode active material, and particularly suitable for occluding lithium in the negative electrode active material containing a carbon material.

  Examples of the binder include rubber-based binders such as styrene-butadiene rubber (SBR) and NBR; fluorine-based resins such as polytetrafluoroethylene and polyvinylidene fluoride; polypropylene, polyethylene, and JP-A-2009-246137. Fluorine-modified (meth) acrylic binders as disclosed.

  The active material layer further includes a conductive agent such as carbon black, graphite, vapor-grown carbon fiber, metal powder; carboxyl methyl cellulose, its Na salt or ammonium salt, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, Thickeners such as oxidized starch, phosphorylated starch, or casein may be contained.

The thickness of the active material layer is not particularly limited, but is usually 5 to 500 μm, preferably 10 to 200 μm, and particularly preferably 10 to 100 μm.
In the case of an electrode used for a lithium ion secondary battery, the density of the active material layer is preferably 1.50 to 2.00 g / cc, particularly preferably 1.60 to 1.90 g / cc. In the case of an electrode used for a capacitor, it is preferably 0.50 to 1.50 g / cc, and particularly preferably 0.70 to 1.20 g / cc.

  The material of the current collector is preferably copper, nickel, stainless steel or the like when the manufacturing method of the present invention is applied to the negative electrode, while aluminum, stainless steel, or the like is preferable when the manufacturing method of the present invention is applied to the positive electrode. preferable. The thickness of the current collector is usually 5 to 50 μm regardless of whether the current is positive or negative. In the production method of the present invention, it is not necessary to use a current collector having a through-hole, but the surface roughness of the current collector to be used may be either positive or negative from the viewpoint of the adhesion of the active material layer. The arithmetic average roughness Ra is preferably 0.05 to 5 μm, particularly preferably 0.1 to 2 μm.

  Although the form is not specifically limited as a lithium supply source, For example, a lithium metal plate, a lithium alloy plate, etc. are mentioned. These thicknesses are usually 0.03 to 3 mm. When the method described later is adopted as a method for occluding lithium in the active material, the lithium supply source is preferably disposed on the conductive substrate. The conductive substrate may be porous. Examples of the material for the conductive substrate include copper, stainless steel, nickel, and the like.

  In the chamber, the current collector on which the active material layer is formed and the lithium supply source may be arranged so that the lithium supply source and the active material layer are in direct contact with each other, but are arranged so that they are in contact with each other via a separator. It is preferable that As a separator used at this time, the same separator as a general separator constituting an electricity storage device can be used.

In the step (A), in order to enhance a desired effect, the inside of the chamber is preferably decompressed to 10 kPa or less, more preferably 1 kPa or less, and particularly preferably 0.1 kPa or less.
Step (B) The organic solvent containing lithium ions is preferably an organic solvent in which a lithium salt is dissolved. Examples of the lithium salt include LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiPF ₆ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , LiC ₄ BO. ₈ etc. are mentioned. These can be used alone or in admixture of two or more.

  The organic solvent is preferably an aprotic organic solvent, specifically, ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, acetonitrile, dimethoxyethane, tetrahydrofuran, Examples include dioxolane, methylene chloride, sulfolane and the like. These organic solvents can be used alone or in admixture of two or more.

  In the organic solvent containing lithium ions, additives such as vinylene carbonate, vinyl ethylene carbonate, 1-fluoroethylene carbonate, 1- (trifluoromethyl) ethylene carbonate, succinic anhydride, maleic anhydride, propane sultone, diethyl sulfone, etc. May be contained.

  The concentration of lithium ions (lithium salt) in the organic solvent containing lithium ions is preferably 0.1 mol / L or more, and more preferably in the range of 0.5 to 1.5 mol / L. .

The supply amount and supply speed of the organic solvent containing lithium ions are appropriately set according to the volume of the chamber.
(C) Process Although it does not specifically limit as a method of occluding lithium in an active material, The method of short-circuiting the electrical power collector in which the said active material layer was formed, and the said lithium supply source, or the said active material layer A method in which a direct current is passed between the current collector formed with the above-described lithium supply source is preferable.

  In the method of short-circuiting the current collector on which the active material layer is formed and the lithium supply source, the conductive base material on which the current collector and the lithium supply source are disposed is used as a terminal, and a conductor such as a metal wire is provided between both terminals. It is only necessary to electrically connect with. Although the time to short-circuit is suitably set according to the area, thickness, etc. of an active material layer, it is 1-1000 hours normally, Preferably it is 5-500 hours.

On the other hand, in a method of passing a direct current between a current collector formed with an active material layer and a lithium supply source, a direct current stabilization power source is used with the current collector and the conductive substrate on which the lithium supply source is disposed as a terminal. The positive terminal may be connected to the conductive base material on which the lithium supply source is disposed, and the negative terminal of the DC stabilized power source may be connected to the current collector. The current when energizing is appropriately set according to the area, thickness, and the like of the active material layer.
(D) Step In the production process of the present invention, after the step (B), further, (D) providing a step of increasing the pressure in the chamber to a higher pressure than after the step (A), It is preferable at the point which raises a desired effect.

  In the step (D), the pressure in the chamber is preferably increased to 10 kPa or more, more preferably 50 kPa or more, and particularly preferably increased to atmospheric pressure. You may pressurize, after returning the pressure in a chamber to atmospheric pressure.

The step (D) may be performed in parallel with the step (C) after the step (B), but is preferably performed before the step (C).
The manufacturing method of the present invention is suitable for manufacturing a negative electrode of a battery or a capacitor. More specifically, it is suitable for the production of negative electrodes of air batteries as primary batteries in addition to power storage devices such as lithium ion capacitors, lithium ion secondary batteries, and air batteries (secondary batteries). Suitable for manufacturing negative electrodes.
[Power storage device]
The electricity storage device of the present invention includes a positive electrode, a negative electrode, and an electrolyte, and at least one of the positive electrode and the negative electrode is an electrode manufactured by the manufacturing method of the present invention. The electricity storage device is not particularly limited as long as it is an electricity storage device that utilizes insertion / extraction of lithium ions, but is preferably a lithium ion capacitor, a lithium ion secondary battery, or an air battery, particularly lithium ion A capacitor is preferred. Moreover, it is preferable that the electrical storage device of this invention is equipped with the negative electrode manufactured by the manufacturing method of this invention.

  When the electricity storage device of the present invention includes the negative electrode manufactured by the manufacturing method of the present invention, the basic configuration of the positive electrode is the same as the configuration of the positive electrode described in the step (A) of the “electrode manufacturing method”. However, as the positive electrode active material, organic active materials such as nitroxy radical compounds and oxygen can be used in addition to those already exemplified.

  On the other hand, when the electricity storage device of the present invention includes the positive electrode manufactured by the manufacturing method of the present invention, the basic configuration of the negative electrode is the same as the configuration of the negative electrode described in the step (A) of the “electrode manufacturing method”. However, as the negative electrode active material, metal lithium, lithium alloy and the like can be used in addition to those already exemplified.

  In the electricity storage device of the present invention, the electrolyte is usually used in the state of an electrolytic solution dissolved in a solvent. The basic configuration of the electrolytic solution is the same as the configuration of the organic solvent containing lithium ions described in the step (B) of the “electrode manufacturing method”. The electrolyte is usually prepared and used in a liquid state, but a gel or solid electrolyte may be used for the purpose of preventing leakage.

  When the electrolyte is used in the state of an electrolyte, a separator is usually provided between the positive electrode and the negative electrode so that the positive electrode and the negative electrode are not in physical contact. As a separator, the nonwoven fabric or porous film which uses a cellulose rayon, polyethylene, a polypropylene, polyamide, polyester, a polyimide etc. as a raw material can be mentioned, for example.

As the structure of the electricity storage device, for example, a laminated cell in which a laminated body in which three or more plate-like positive electrodes and negative electrodes are laminated via a separator is enclosed in an exterior film, and a strip-like positive electrode and negative electrode are separators. Examples include a wound cell in which a laminated body wound through a container is accommodated in a rectangular or cylindrical container.
[Device for occluding lithium in the electrode active material]
An apparatus 1 used for occluding lithium in an active material of an electrode using the electrode manufacturing method of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the apparatus 1 includes a chamber 10, a holding unit 30, a spare chamber 40, a pump unit (decompression unit) 45, a supply unit (supply unit) 50, and a power supply unit 55. And a control unit 60 are mainly provided.

  The chamber 10 is a container having a processing space SP1 in which lithium is stored in the electrode active material. The processing space SP1 of the chamber 10 is connected to the pump unit 45 through the first decompression pipe 71 so as to be able to communicate with it, and communicates with the spare chamber 40 through the second decompression pipe 72 branched from the first decompression pipe 71. Connected as possible. Furthermore, it is connected to the supply unit 50 via a liquid injection pipe 73 so that liquid injection is possible. Further, a leak pipe 74 and a leak valve 85 are provided as means for enabling the inside of the chamber 10 to communicate with the outside air. In the present embodiment, the first pressure reducing pipe 71, the second pressure reducing pipe 72, and the liquid injection pipe 73 will be described by being applied to an example formed using a resin.

  As shown in FIGS. 2 and 3, the chamber 10 mainly includes a chamber main body 11, a chamber lid portion 21, and a packing 25 that constitute the processing space SP <b> 1. In the processing space SP1, a packing 25 in which an elastic member such as rubber is annularly formed is sandwiched between the chamber body 11 and the chamber lid portion 21, and the chamber body 11 and the chamber lid portion 21 are fixed to a fixing member (not shown) such as a bolt. )) To form a close contact. In the present embodiment, description will be made by applying to an example in which the chamber body 11 and the chamber lid portion 21 are formed using stainless steel.

  The chamber body 11 is open toward the chamber lid portion 21 and has a recess 12 that forms the processing space SP1. The chamber body 11 is provided with a liquid level sensor 17 and a liquid level measurement pipe 18, and a spacer 19 can be disposed inside the recess 12.

  A first pressure reducing pipe 71 is opened on the pressing side surface 15 of the recess 12, and an end of the liquid injection pipe 73 is opened on the bottom surface 13. Further, the recess 12 is formed with a spacer side surface 14 adjacent to the spacer 19 and a pressing side surface 15 facing the spacer side surface 14 and having an inclined portion 16.

  The inclined portion 16 of the pressing side surface 15 has an inclination approaching the spacer side surface 14 toward the bottom surface 13 and presses the electrode precursor 91, the lithium electrode 96, and the separator 99 together with the holding portion 30. is there. In the present embodiment, description will be made by applying to an example in which the inclined portion 16 is formed in all regions except a portion perpendicular to the bottom surface 13 provided in the vicinity of the chamber lid portion 21 on the pressing side surface 15.

  The liquid level sensor 17 and the liquid level measurement pipe 18 are provided on the pressing side surface 15 side in the chamber body 11, and measure the liquid level of the solution injected into the processing space SP1. One end of the liquid level measurement pipe 18 is open to a portion of the pressing side surface 15 that is perpendicular to the bottom surface 13. The other end portion is a gap formed between the holding portion 30 and the bottom surface 13 of the processing space SP1 when the holding portion 30 is disposed in the vicinity of the bottom surface 13 in the inclined portion 16, in other words, in the processing space SP1. It opens to the position where it communicates with. The liquid level sensor 17 measures the liquid level of the solution in the processing space SP1 by measuring the liquid level of the solution in the liquid level measurement pipe 18. As the liquid level sensor 17, a known sensor can be used, and the type and form thereof are not limited.

  The spacer 19 is disposed so as to be able to be inserted into and removed from the recess 12. By changing the dimension (thickness) of the spacer 19 to be arranged, the interval formed between the pressing side surface 15 can be adjusted. The member forming the spacer 19 may be stainless steel as in the chamber body 11 or the like, or may be resin as in the first decompression pipe 71 or the like.

  The chamber lid 21 forms the processing space SP1 by closing the opening of the recess 12 in the chamber body 11. The chamber lid portion 21 is provided with a doping electrode 22 to which a current is supplied from the power source portion 55 and a through hole 23 into which a guide bar 32 of the holding portion 30 described later is inserted.

  Further, as shown in FIG. 1, the chamber lid portion 21 is provided with a leak pipe 74 and a leak valve 85 as means for connecting the processing space SP1 and the outside air so as to communicate with each other. In the present invention, the means for allowing the inside of the chamber 10 to communicate with the outside air is such that the organic solvent containing lithium ions is positioned above the liquid level of the organic solvent after being supplied into the chamber 10. 10 is preferably connected. The leak valve 85 is provided to open and close the leak pipe 74 to control the flow of gas such as air.

  As shown in FIGS. 2 and 4A, the holding unit 30 holds the electrode precursor 91, the lithium electrode 96, and the separator 99. The held electrode precursor 91, the lithium electrode 96, and The separator 99 is disposed in the processing space SP1. The holding unit 30 mainly includes a lithium electrode 96, a separator 99, an electrode precursor 91, a separator 99, a support unit 31 that sandwiches the lithium electrode 96 in that order, and a pressing unit 35. ing.

  Although not shown, the holding unit 30 holds the space between the support unit 31 and the pressing unit 35 using a guide pin with a span wider than the width of the electrode precursor 91, and the lithium electrode 96, The separator 99, the electrode precursor 91, the separator 99, and the lithium electrode 96 are sandwiched at such a pressure that the lithium electrode 96 does not fall off, but the movable structure is further compressible in the thickness direction.

  In the present embodiment, description will be made by applying to an example in which the support portion 31 and the pressing portion 35 are formed using a resin. However, a material and a configuration that ensure insulation with the doping electrode 22 (chamber 10). Any known materials and configurations can be used as long as they are not particularly limited.

  The support portion 31 is a member formed in a flat plate shape, and is a member that is disposed to face the spacer 19 when the holding portion 30 is disposed in the processing space SP1. The support portion 31 is provided with a pair of guide bars 32 formed in a rod shape extending toward the chamber lid portion 21. The guide bar 32 is inserted into the through hole 23 of the chamber lid portion 21 so as to be detachable, and keeps the relative posture of the holding portion 30 with respect to the chamber body 11 constant.

  2 and 4A, since the pair of guide bars 32 are arranged in a direction perpendicular to the paper surface, only one guide bar 32 is shown, and the other guide bar 32 is one side. Since it is hidden behind the guide bar 32, it is not shown.

  The guide bar 32 is provided with a stopper 33 having a bowl shape. The stopper 33 is disposed closer to the chamber body 11 than the chamber lid 21 when the holding unit 30 is disposed in the processing space SP1. For example, when holding the tip of the guide bar 32 protruding from the chamber lid 21 and pulling up the holding portion 30 from the recess 12, the chamber lid 21 and the holding portion 30 come into contact with each other by a stopper 33 having a diameter larger than that of the through hole 23. Is suppressed.

  The pressing portion 35 is a member formed in a trapezoidal column shape having a trapezoidal cross section, and is a member that is disposed to face the pressing side surface 15 when the holding portion 30 is disposed in the processing space SP1. A pressing surface 36 having an inclination similar to that of the inclined portion 16 is provided on the surface of the pressing portion 35 that faces the pressing side surface 15. In other words, the pressing surface 36 has an inclination that approaches the spacer side surface 14 toward the bottom surface 13 when the holding unit 30 is disposed in the processing space SP1.

  When the holding part 30 is disposed in the processing space SP1, the inclined part 16 and the pressing surface 36 are in contact with each other, and the spacer 19 and the support part 31 are in contact with each other. In this state, when a downward force (force toward the bottom surface 13) is exerted on the holding portion 30 by its own weight, the holding portion 30 is pressed by the inclined portion 16 and the pressing surface 36 having an inclination approaching the spacer side surface 14 toward the bottom surface 13. The force which makes the part 35 and the support part 31 contact | adhere will work. Further, even when the lithium electrode 96 becomes thinner due to the progress of occlusion of lithium, the holding portion 30 moves to the bottom surface 13 side by its own weight, so that the above-described adhesion by the inclined portion 16 and the pressing surface 36 is performed. It becomes possible to keep the power to make.

  As shown in FIG. 4B, the electrode precursor 91 is provided with a rectangular active material layer 93 arranged along the longitudinal direction on both surfaces of a current collector 92 in which a copper foil is formed in a rectangular shape. Is. An active material layer unformed portion 94 extending in the longitudinal direction is formed in the vicinity of one of the pair of long sides of the current collector 92, and the vicinity of the pair of short sides of the current collector 92 and the active material layer 93 An active material layer non-formed portion 95 extending in the short direction is formed therebetween. The electrode precursor 91 can be electrically connected to one of the pair of doping electrodes 22 in the active material layer unformed portion 94 of the current collector 92.

  As shown in FIG. 4C, the lithium electrode 96 has a lithium metal plate 98 arranged along the longitudinal direction on one surface of a rectangular copper plate 97. The lithium metal plate 98 is arranged to face the active material layer 93 of the electrode precursor 91 when held by the holding unit 30. The two lithium electrodes 96 are electrically connected to each other and can be electrically connected to the other of the pair of doping electrodes 22.

  The separator 99 is disposed between the lithium electrode 96 and the electrode precursor 91. In the present embodiment, description will be made by applying to an example in which the separator 99 is a nonwoven fabric made of polypropylene.

  As shown in FIGS. 1 and 3, the preliminary chamber 40 is a container that forms a preliminary space SP <b> 2 that communicates with the processing space SP <b> 1 through the first pressure reducing pipe 71 and the second pressure reducing pipe 72. The preliminary chamber 40 is used when the processing space SP1 is decompressed together with the pump unit 45. One end of the second decompression pipe 72 communicates with the spare space SP2 of the spare chamber 40, and the other end communicates with the first decompression pipe 71.

  A spare chamber side cock (connection control means) 82 is provided on the spare chamber 40 side of the second decompression pipe 72, and a pump side cock (connection control means) 83 is provided on the first decompression pipe 71. The spare chamber side cock 82 controls the flow of the fluid by opening and closing the second decompression pipe 72.

  The spare chamber 40 is used as follows. After the step (A) in the “electrode manufacturing method”, the pressure in the spare space SP2 is opened by opening the spare chamber side cock 82 and the pump side cock 83 with the decompression cock 81 closed and driving the pump unit 45. The pressure is reduced. When the pressure in the spare space SP2 decreases to a predetermined value, the spare chamber side cock 82 and the pump side cock 83 are closed, and the pump unit 45 is stopped.

  Next, by opening the decompression cock and the spare chamber side cock 82, the spare space SP2 of the spare chamber 40 decompressed in advance by the pump unit 45 and the processing space SP1 are communicated. As a result, the pressure in the processing space SP1 is reduced.

  Next, the preliminary chamber side cock 82 is closed, the pump side cock 83 is opened with the decompression cock 81 opened, and the pump unit 45 is driven to further decompress the processing space SP1 of the chamber 10. Thereafter, the process proceeds to the process (B) and the process (C). During that time, the pressure in the spare space SP2 is reduced in the same manner as described above.

  If it does in this way, when manufacturing an electrode continuously with the manufacturing method of the present invention, the time which the above-mentioned (A) process requires can be shortened. In the present embodiment, description will be made by applying to an example in which the auxiliary chamber 40, the second decompression pipe 72, the auxiliary chamber side cock 82, and the pump side cock 83 are not provided.

  The pump unit 45 communicates with the processing space SP1 through the first decompression pipe 71 and further communicates with the spare space SP2 through the second decompression pipe 72, and the pump section 45 is connected to the processing space SP1 and the spare space SP2. The pressure is reduced. In the present embodiment, description will be made by applying to an example in which the pump unit 45 is a scroll-type dry vacuum pump, but other known decompression pumps can be used and are not particularly limited.

  One end of the first decompression pipe 71 is in communication with the processing space SP1, and the other end is in communication with the suction part of the pump unit 45. Further, a decompression cock (connection control means) 81 is provided between a communication side end portion of the first decompression pipe 71 with the processing space SP1 and a communication part with the second decompression pipe 72. The decompression cock 81 controls the flow of fluid by opening and closing the first decompression pipe 71.

  As shown in FIG. 1, the supply unit 50 communicates with the processing space SP <b> 1 via the liquid injection pipe 73 and supplies a solution that is an organic solvent containing lithium ions to the processing space SP <b> 1. As the supply unit 50, a container made of a material that does not dissolve in the organic solvent to be used and does not react with the organic solvent can be used, and the configuration is not particularly limited.

  The liquid injection pipe 73 is provided with a liquid injection cock 84 that opens and closes the liquid injection pipe 73 to control the flow of the solution. In the present invention, the supply means is preferably connected to the chamber 10 so that the organic solvent containing lithium ions is supplied into the chamber 10 from the bottom surface 13 side.

  As shown in FIGS. 1 and 2, the power supply unit 55 supplies a direct current to the electrode precursor 91 and the lithium electrode 96 through the doping electrode 22. In the present embodiment, description will be made by applying to an example of a DC power supply with a current / voltage monitor that can supply a DC current to the electrode precursor 91 and the lithium electrode 96.

  As shown in FIG. 5, the control unit 60 controls the apparatus 1 to execute a step of occluding lithium in the active material of the electrode. The control unit 60 is a computer system having a CPU (Central Processing Unit), ROM, RAM, hard disk, input / output interface, and the like. The control program stored in the ROM or the like causes the CPU to function as the calculation unit 61, causes the input / output interface or the like to function as the transmission / reception unit 62, and causes the hard disk or the like to function as the storage unit 63. .

  The arithmetic unit 61 generates a control signal for controlling supply / stop of the current by the power supply unit 55 and the value of the supplied current. In addition, the control signal for adjusting the pressure in the processing space SP1 of the chamber 10 and the pressure in the spare space SP2 of the spare chamber 40 is generated by controlling the driving / stopping of the pump part 45 and the pump part 45 and the like. . Furthermore, it also generates a control signal for controlling supply / stop of the solution by the supply unit 50. In addition, a control signal for controlling the opening / closing of the decompression cock 81, the injection cock 84, the spare chamber side cock 82, the pump side cock 83, and the leak valve 85 is also generated.

  The pressure in the processing space SP1 and the pressure in the spare space SP2 may be adjusted according to the driving time of the pump unit 45, or a pressure sensor that measures the pressure in the processing space SP1 and the pressure in the spare space SP2. The adjustment may be made based on the measurement signal of the pressure sensor, and is not particularly limited.

  The transmission / reception unit 62 receives the measurement signal output from the liquid level sensor 17 and also transmits various control signals generated by the calculation unit 61 to the target device. The transmission / reception unit 62 includes a signal indicating the operation state of the power supply unit 55, the pump unit 45, and the supply unit 50, a decompression cock 81, a liquid injection cock 84, a spare chamber side cock 82, and a pump side. A signal indicating the open / closed state of the cock 83 or the leak valve 85 may be received.

  The storage unit 63 stores a program, a parameter, and the like for executing the step of occluding lithium in the above-described electrode active material. The storage unit 63 can output the above-described program, parameters, and the like based on the control signal input from the calculation unit 61.

Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. The following Examples and Comparative Examples were performed in an air environment controlled at an air temperature of 23 ° C. and a dew point of −40 ° C.
<Manufacture of electrodes>
[Example 1]
An active material layer 93 having a thickness of 52 mm × 52 mm and a thickness of 40 μm is provided on both sides of the current collector 92 made of copper foil having a thickness of 70 mm × 382 mm, a thickness of 15 μm, and a surface roughness Ra = 0.1 μm in the longitudinal direction of the current collector 92. The electrode precursor 91 was produced by forming six places along each. At this time, the active material layer unformed portion 94 having a width of 18 mm extending along the longitudinal direction at one end portion of the long side of the current collector 92, and between the both end portions of the short side of the current collector 92 and the active material layer 93 An active material layer non-formed part 95 having a width of 10 mm extending in the short direction was provided. Note that the active material layer 93 includes graphite (active material), carboxymethyl cellulose, acetylene black (conductive agent), a binder, and a dispersant (by mass ratio: 88: 3: 5: 3: 1).

  A lithium electrode 96 was produced by attaching six lithium metal plates 98 formed as 50 mm × 50 mm and a thickness of 1 mm as a lithium supply source to a copper plate 97 having a thickness of 2 mm with a spacing of 12 mm between each other. . Two such lithium electrodes 96 were produced.

  The lithium electrodes 96 were arranged on both surfaces of the electrode precursor 91 so that the active material layer 93 and the lithium metal plate 98 face each other through a separator 99 made of a polypropylene nonwoven fabric having a thickness of 1 mm. At this time, the electrode precursor 91 and the lithium electrode 96 were disposed so that the center positions of the facing active material layer 93 and the lithium metal plate 98 substantially coincided with each other.

  The electrode precursor 91, the separator 99, and the lithium electrode 96 were inserted into the processing space SP <b> 1 of the chamber 10 together with the holding unit 30. At this time, the electrode precursor 91 and the like are arranged so that the active material layer non-formed part 94 having a width of 18 mm provided at the end of the long side of the current collector 92 is positioned on the upper side (chamber lid part 21 side) in the chamber 10. Inserted.

  Next, the processing chamber SP1 of the chamber 10 was decompressed by driving the pump unit 45 with the preliminary chamber side cock 82 closed and the pump side cock 83 and the decompression cock 81 opened. The inside of the processing space SP1 of the chamber 10 was depressurized to 100 Pa, and the depressurization cock 81 was closed.

Subsequently, a solution containing 1.2 M LiPF6 and 3% by mass of 1-fluoroethylene carbonate (solvent is ethylene carbonate / ethyl methyl carbonate / dimethyl carbonate = 3/4/3 (volume ratio) ) Was supplied to the treatment space SP1. When the liquid level of the solution containing LiPF ₆ or the like reached 5 mm above the upper end of the active material layer 93, the injection cock 84 provided in the injection pipe 73 was closed.

Subsequently, the leak valve 85 provided in the upper part of the chamber 10 was opened, the pressure in the chamber 10 was raised, and it returned to atmospheric pressure.
Next, a current of 300 mA was passed through the electrode precursor 91 and the lithium electrode 96 connected to the power supply unit 55 via the doping electrode 22. In consideration of the irreversible capacity, electricity was supplied until the lithium occlusion rate was about 87% of the graphite capacity.

When the lithium-occluded electrode was taken out from the chamber 10 as described above, the entire surface of the active material layer was uniformly changed to gold.
[Example 2]
In Example 1, an electrode in which lithium was occluded was produced in the same manner as in Example 1 except that the step of returning the pressure in the chamber 10 to atmospheric pressure was not performed. When the obtained electrode was taken out from the chamber, the entire surface of the active material layer was discolored in gold, but color unevenness was observed.
[Comparative example]
The comparative example is different from the above-described first embodiment in that the step of depressurizing the inside of the chamber 10 is performed after the step of injecting a solution containing LiPF ₆ or the like into the processing space SP1 of the chamber 10.

Specifically, the electrode precursor 91 and the like produced in the same manner as in Example 1 were inserted into the processing space SP1 of the chamber 10 together with the holding unit 30. Next, a solution containing LiPF ₆ or the like similar to that used in Example 1 was injected into the processing space SP1 of the chamber 10 until the liquid level reached 5 mm above the upper end of the active material layer 93.

  Next, the inside of the chamber 10 was depressurized in the same manner as in Example 1 using the pump unit 45, the spare chamber 40, and the like. After reducing the pressure in the chamber 10 to 100 Pa, the pressure reducing cock 81 provided in the first pressure reducing piping 71 was closed. Next, the leak valve 85 provided at the upper part of the chamber 10 was opened, and the pressure in the chamber 10 was increased to return to atmospheric pressure. Next, an electrode in which lithium was occluded was manufactured in the same manner as in Example 1 through the doping electrode 22 provided in the upper part of the chamber 10.

When the obtained electrode was taken out from the chamber 10, several black regions having a size of the cm diameter level were found on the active material layer 93. In these areas, it can be said that occlusion of lithium is not progressing.
<Manufacture of lithium ion capacitors>
A lithium ion capacitor was produced by a conventional method using the electrode produced in the above example as the negative electrode. The obtained lithium ion capacitor exhibited excellent charge / discharge characteristics. On the other hand, when the lithium ion capacitor was similarly manufactured using the electrode manufactured in the comparative example as a negative electrode, the obtained lithium ion capacitor had a large amount of gas generated when held in a charged state. In the negative electrode manufactured in the comparative example, it is considered that a portion where a so-called SEI film is not formed partially exists.

  DESCRIPTION OF SYMBOLS 1 ... Apparatus, 10 ... Chamber, 40 ... Preliminary chamber, 45 ... Pump part (pressure reduction means), 50 ... Supply part (supply means), 81 ... Decompression cock (connection control means), 82 ... Reserve chamber side cock (connection) Control means), 83... Pump side cock (connection control means)

Claims (7)

(A) a step of depressurizing the inside of the chamber containing the current collector on which the layer containing the active material is formed and the lithium supply source;
(B) supplying an organic solvent containing lithium ions into the decompressed chamber; and
(C) The manufacturing method of the electrode including the process of occluding lithium in the said active material.   Furthermore, after the said (B) process, (D) The manufacturing method of Claim 1 including the process which raises the atmospheric pressure in the said chamber to the atmospheric pressure higher than the atmospheric pressure after the said (A) process.   The manufacturing method according to claim 1, wherein the electrode is a capacitor or a negative electrode of a battery.   The manufacturing method of any one of Claim 1 to 3 whose said active material is what contains a carbon material.   An electrical storage device provided with the negative electrode manufactured by the method of any one of Claim 1 to 4, a positive electrode, and electrolyte. (1) a chamber containing a current collector on which a layer containing an active material is formed and a lithium supply source;
(2) An apparatus for occluding lithium in an active material of an electrode, comprising: decompression means for decompressing the inside of the chamber; and (3) supply means for supplying an organic solvent containing lithium ions into the chamber. Further, (4) a spare chamber that is connected to the inside by the pressure reducing means so as to be able to be depressurized, and is connected to be able to flow a gas between the inside of the chamber;
(5) connection control means for controlling connection between the chamber and the decompression means, connection between the preliminary chamber and the decompression means, and connection between the chamber and the preliminary chamber;
The apparatus of claim 6, comprising: