JP2019067730A - Power storage device electrode, power storage device, and method of manufacturing power storage device electrode - Google Patents

Abstract

To provide a power storage device electrode with high strength for which high connection reliability is secured even when a current collector plate, in which an electrode unit including silicon as an active material is disposed, is used.SOLUTION: A power storage device electrode is characterized by comprising: a current collector plate configured from a body part and a lead-out part; an electrode unit disposed in the body part of the current collector plate; and a lead wire connected to the lead-out part of the current collector plate. In the power storage device electrode, the lead-out part and the body part are formed from homogeneous stainless steel, the stainless steel is austenitic stainless steel including a martensite structure, and the electrode unit includes silicon as an active material.SELECTED DRAWING: Figure 1

Description

The present invention relates to a storage device electrode, a storage device, and a method of manufacturing the storage device electrode.

An electricity storage device using a metal having a large ionization tendency such as lithium is used in many fields because it can store a large amount of energy.
As a method of manufacturing such an electric storage device, Patent Document 1 includes, as a positive electrode active material, a carbonaceous material formed on a positive electrode current collector plate having a through hole and having a layered structure capable of inserting and desorbing anions. A positive electrode, a negative electrode containing a carbonaceous material having a layered structure capable of inserting and removing lithium ions, formed on a negative electrode current collector plate having through holes, as a negative electrode active material, and a non-aqueous electrolyte containing a lithium salt And a lithium ion source and a laminate formed by laminating the positive electrode and the negative electrode with a separator interposed therebetween in the cell for a storage device, and the non-aqueous electrolyte solution. Cell preparation process for injecting electricity, charge / discharge process for charging / discharging between positive electrode and lithium ion source, and electrochemical contact between negative electrode and lithium ion source Method for manufacturing a power storage device, characterized in that it comprises a and a storage step of occluding lithium ions in the negative electrode is disclosed.

In the method of manufacturing an electricity storage device described in Patent Document 1, metallic lithium is used as a lithium ion supply source. Charge and discharge is performed between the positive electrode and the lithium ion supply source using such a lithium ion supply source, and electrochemical contact is made between the negative electrode and the lithium ion supply source, and lithium ion is absorbed in the negative electrode. I am doing it.

When a power storage device is manufactured by such a method described in Patent Document 1, metal lithium, which is a lithium ion supply source, remains in the power storage device.
Lithium metal contained in the lithium ion source is a material which is easily ignited and is dangerous. Therefore, it is desirable that metal lithium does not remain in the storage device.

Patent Document 2 describes the use of a carbonaceous material pre-doped with lithium ions as such a lithium ion source.
That is, it is described that a carbonaceous material is fixed to a current collector plate, lithium ions are absorbed between layers of the carbonaceous material by intercalation, and this is used as a lithium-containing electrode.
By using such a lithium ion-containing electrode, charging and discharging can be performed between the positive electrode and the lithium ion source without using lithium metal, and further, electrochemistry can be performed between the negative electrode and the lithium ion source. Contact can be made to occlude lithium ions in the negative electrode.

However, when lithium ions are stored in the carbonaceous material by intercalation, the storage amount of lithium ions has a theoretical upper limit of 372 mAh / g, which can not be exceeded. For this reason, examination of material which can occlude more lithium ions than carbonaceous material was performed.

JP, 2014-211950, A JP, 2016-103609, A

Silicon is known as a material capable of alloying with lithium ions and capable of absorbing lithium ions. When lithium is stored using silicon, it is theoretically said that lithium ions of 4000 mAh / g or more can be stored.
That is, when lithium is stored using silicon, the storage and release amount of lithium ion per unit volume is large, and the capacity of the power storage device can be increased.
However, there is a problem that expansion and contraction of the active material itself become large when lithium ions are absorbed and released.
Therefore, when silicon is fixed to a current collecting plate and used as an electrode, large distortion occurs in the current collecting plate, and there is a problem that the current collecting plate is warped or wrinkled. Because of these problems, when silicon is used as an active material, there is a problem that the current collector is deformed in the storage device or the connection reliability is lowered.

In the present invention, even when using a current collector plate in which an electrode portion containing silicon is disposed as an active material, it is possible to provide a high strength electrode for a storage device having high connection reliability and a method of manufacturing the same. An object of the present invention is to provide a storage device in which the storage device electrode is used.

(1) The electrode for a storage battery device of the present invention is
A current collector consisting of a main body portion and a lead portion;
An electrode portion disposed in the main portion of the current collector plate;
An electrode for a storage device comprising a lead wire connected to the lead-out portion of the current collector plate,
The lead-out portion and the body portion are formed of the same stainless steel,
The above stainless steel is an austenitic stainless steel containing a martensitic structure,
The electrode unit is characterized in that it contains silicon as an active material.

In the electrode for a storage battery device of the present invention, the current collector plate is formed of an austenitic stainless steel including a martensitic structure.
The martensitic structure is high in hardness. Therefore, when the current collector is made of an austenitic stainless steel containing a martensitic structure, the current collector can be made hard and have high strength. Therefore, it is easy to prevent the occurrence of warpage or wrinkles in the current collector plate.
Therefore, even if metal ions are occluded in the active material of the electrode part or metal ions occluded in the active material of the electrode part are released and the volume of the active material changes, the current collector plate is warped or wrinkled. It will be easier to prevent.

In the storage device electrode of the present invention, the lead-out portion connected to the lead wire and the main body portion are formed of the same stainless steel.
That is, when connecting the lead wire and the current collector plate, the current collector plate is connected by a method which does not deteriorate the heat without applying heat.
Therefore, the strength of the lead-out portion connected to the lead wire becomes sufficiently strong, and the function of the current collector plate also becomes difficult to deteriorate.

Further, it is desirable that the electrode for a storage device of the present invention be in the following mode.

(2) In the electrode for a storage battery device of the present invention, it is desirable that the martensitic structure be interspersed in an austenite structure in the cross section obtained by cutting the current collector plate along the thickness direction.
The fact that the martensitic structure is scattered like islands in the austenite structure means that the austenitic structure content (mass) is larger than the martensite structure content (mass).
Since the austenite structure is chemically stable, the collector plate of such a configuration is resistant to corrosion and elution.

(3) In the storage device electrode of the present invention, it is desirable that the lead wire has a smaller elastic modulus than the current collector plate.
If the lead wire has a smaller elastic modulus than the current collector plate, the lead wire absorbs external force or vibration when subjected to external force or vibration. Therefore, it becomes difficult to apply strong force to the connection part of a lead wire and a current collection board, and the connection part of a lead wire and a current collection board becomes difficult to be damaged.

(4) In the storage device electrode of the present invention, the lead wire is preferably made of at least one selected from the group consisting of nickel, copper, aluminum and brass.
These materials have high electric conductivity and are excellent as lead wire materials.
In addition, these substances can be firmly connected to stainless steel by ultrasonic welding. Therefore, the connection strength between the lead wire and the current collector plate can be sufficiently high.

(5) In the storage device electrode of the present invention, the lead wire may be plated with at least one selected from the group consisting of nickel, gold, silver, zinc and chromium.
These materials can be rigidly connected to stainless steel by ultrasonic welding. Therefore, the connection strength between the lead wire on which these substances are plated and the current collector plate can be sufficiently high.
Moreover, a material with a low elastic modulus can be used as a core material of a lead wire, and the elastic modulus of the whole lead wire can be made low.

(6) In the electrode for a storage battery device of the present invention, it is desirable that the active material be made of only silicon.
Silicon can occlude metal ions by alloying with the metal ions.
Therefore, for example, it is possible to occlude more metal ions than a substance such as carbon which occludes metal ions by intercalation. In particular, lithium ions can store 4000 mAh / g or more.
Therefore, the electrical capacity becomes sufficiently large.
As described above, when silicon occludes a large amount of metal ions or when a large amount of metal ions are released from silicon, the volume of silicon which is an active material largely changes. When the volume of silicon changes in this manner, wrinkles and warpage easily occur on the current collector plate.
However, in the storage device electrode of the present invention, the current collector plate is formed of austenitic stainless steel including a martensitic structure. Therefore, even if the volume of silicon changes, warpage or wrinkles are less likely to occur in the current collector plate.

(7) The electrode for a storage battery device of the present invention may be used as a metal ion supply electrode for supplying metal ions to an electrolytic solution.
The storage device electrode of the present invention can be used not only as the positive electrode or the negative electrode of the storage device but also as a metal ion supply electrode.

(8) The electricity storage device of the present invention is characterized by comprising the electrode for an electricity storage device of the present invention.
Therefore, in the electricity storage device of the present invention, wrinkles and warpage are less likely to occur in the current collector plate of the electrode for electricity storage device.

(9) The method for producing an electrode for a storage battery device of the present invention,
A current collector consisting of a main body portion and a lead portion;
An electrode portion disposed in the main portion of the current collector plate;
A method of manufacturing an electrode for a storage battery device, comprising: a lead wire connected to the lead-out portion of the current collector plate,
Including an ultrasonic connection step of connecting the lead portion and the lead portion by ultrasonic welding;
The current collector plate is formed of an austenitic stainless steel containing a martensitic structure,
The electrode unit is characterized in that it contains silicon as an active material.

In the method of manufacturing an electrode for a storage battery device of the present invention, the current collector plate and the lead wire are connected by ultrasonic welding.
When a part of the current collector plate or a part of the lead wire is melted by heat such as resistance welding to connect the current collector plate and the lead wire, the stainless steel forming the current collector plate is degraded by the heat. When such a deterioration occurs, there is a problem that a partial thermal distortion occurs to reduce the function of the current collector plate.
On the other hand, ultrasonic welding is a method by which metals can be connected without generating heat. Therefore, if ultrasonic welding is used, the current collector plate and the lead wire can be connected without deteriorating the current collector plate. Therefore, the strength of the lead-out portion connected to the lead wire is sufficiently strong, and the function of the current collector plate is also less likely to be deteriorated.

In the storage device electrode of the present invention, the lead-out portion connected to the lead wire and the main body portion are formed of the same stainless steel.
That is, when connecting the lead wire and the current collector plate, the current collector plate is not deteriorated.
Therefore, partial thermal distortion hardly occurs, the strength of the lead-out portion connected to the lead wire becomes sufficiently strong, and the function of the current collector plate also becomes difficult to deteriorate.

FIG. 1 is a cross-sectional view schematically showing an example of an electrode for a storage device of the present invention. FIG. 2: is sectional drawing which shows typically an example of the cross section which cut | disconnects the current collection board in the thickness direction in the electrode for electrical storage devices of this invention.

(Detailed Description of the Invention)
Hereinafter, although the electrode for electrical storage devices of this invention is demonstrated using drawing, the electrode for electrical storage devices of this invention is not limited to the following description.

FIG. 1 is a cross-sectional view schematically showing an example of an electrode for a storage device of the present invention.
As shown in FIG. 1, the storage device electrode 10 includes a current collector plate 20, an electrode portion 30 formed on both sides of the current collector plate 20, and a lead wire 40 connected to an end of the current collector plate 20. It consists of

In addition, the lead-out portion 21 and the main body portion 22 are formed of the same quality stainless steel.

The stainless steel forming the current collector plate 20 is an austenitic stainless steel containing a martensitic structure.
In addition, the electrode unit 30 contains silicon as an active material.

In the storage device electrode 10, the current collector plate 20 is formed of austenitic stainless steel including a martensitic structure.
The martensitic structure is high in hardness. Therefore, when the current collector plate 20 is formed of an austenitic stainless steel including a martensitic structure, the current collector plate 20 can be hard and have high strength. Therefore, it is easy to prevent the occurrence of warpage or wrinkles in the current collector plate 20.
Therefore, even if metal ions are absorbed in the active material of the electrode unit 30 or metal ions absorbed in the active material of the electrode unit are released and the volume of the active material changes, the current collector plate 20 is warped or wrinkled. Is more likely to be prevented.

In the storage device electrode 10, the lead-out portion 21 and the main body portion 22 are formed of the same stainless steel.
Although mentioned later in detail, when connecting the lead wire 40 and the current collector plate 20, the current collector plate 20 is not deteriorated.
Therefore, partial thermal distortion hardly occurs, and the main body portion 22 has sufficient strength.

In the storage device electrode 10, it is desirable that the martensitic structure be scattered in the form of islands in the austenite structure in the cross section in which the current collector plate 20 is cut along the thickness direction.
The state in which the martensitic structure is scattered in the form of islands in the austenitic structure will be described below with reference to the drawings.

FIG. 2: is sectional drawing which shows typically an example of the cross section which cut | disconnects the current collection board in the thickness direction in the electrode for electrical storage devices of this invention.
In FIG. 2, reference numeral 26 denotes a martensitic structure, and reference numeral 27 denotes an austenitic structure.
In the present specification, “the state in which the martensitic structure is scattered in the form of islands in the austenite structure” means that the martensitic structure 26 is not unevenly distributed in one place, as shown in FIG. Means to be present in the macula.

The fact that the martensitic structure is scattered like islands in the austenite structure means that the austenitic structure content (mass) is larger than the martensite structure content (mass).
Since the austenite structure is chemically stable, the collector plate of such a configuration is resistant to corrosion and elution.

The presence of martensitic structure and austenitic structure can be analyzed by the electron backscattering diffraction pattern measurement method (EBSD method) under the following conditions.

(Conditions of EBSD method)
<Analyzer>
EF-SEM: JSM-7000F / EBSDD manufactured by Nippon Denshi Co., Ltd .: TSL Solution
<Analytical conditions>
Range: 14 x 36 μm
Step: 0.05 μm / step
Measurement point: 233376
Magnification: 5000 times phase: γ-iron, α-iron

In the present specification, “the lead-out portion and the main body portion are formed of the same quality stainless steel” means a structure in which the tissues constituting the lead-out portion and the main body portion are continuous, and the EBSD is It means that the measurement by the method is performed and the following results are obtained.
That is, "the lead-out portion and the main body portion are formed of the same quality stainless steel",
It is a structure in which the structure forming the lead-out portion 21 and the main body portion 22 is continuous, and there is no interface between them, and martensite in a cross section which cuts the lead-out portion 21 along the thickness direction This means that the area of the structure is 5 to 20% of the entire cross section, and the area of the martensitic structure is 5 to 20% of the entire cross section when the main body 22 is cut along the thickness direction.

Further, in the cross section in which the lead portion 21 is cut along the thickness direction, the area of the martensitic structure is preferably 5 to 20% of the entire cross section.
Moreover, in the cross section which cut | disconnects the main-body part 22 along the thickness direction, it is desirable for the area of a martensitic structure to be 5 to 20% of the whole cross section.
If the area of the martensitic structure of the cross section which cuts the lead-out portion 21 along the thickness direction and the area of the martensitic structure of the cross section which cuts the main body 22 along the thickness direction are within the above range The plate is less susceptible to corrosion and also has high strength.
Moreover, in the said cross section, when the area which a martensitic structure occupies is less than 5%, it will become difficult to acquire the strength improvement effect of the current collector plate by containing a martensitic structure.
In the above cross section, when the area occupied by the martensitic structure exceeds 20%, the martensitic structure is easily exposed to the surface and continuously connected to the martensitic structure existing inside, and the entire current collector plate is corroded. It becomes easy to do. In addition, since the proportion of the martensitic structure is increased, the toughness of the current collector plate is easily reduced. As a result, the current collector plate is easily broken.

In the storage device electrode 10, the thickness of the current collector plate 20 is preferably 5 to 50 μm.
If the thickness of the current collector plate is less than 5 μm, the current collector plate is easily broken because it is too thin.
If the thickness of the current collector plate is more than 50 μm, it is too thick, and the size of the power storage device using the electrode for a power storage device including the current collector plate with such a thickness tends to be large.

The tensile strength of the current collector plate 20 is not particularly limited, but preferably 300 to 1500 MPa.

In the electrode 10 for a storage device, it is desirable that the lead wire 40 has a smaller elastic modulus than the current collector plate 20.
When the lead wire 40 has a smaller elastic modulus than the current collector plate 20, the lead wire 40 absorbs external force or vibration when it receives an external force or vibration. Therefore, it becomes difficult to apply strong force to the connection part of lead wire 40 and current collection board 20, and the connection part of lead wire 40 and current collection board 20 becomes difficult to be damaged.

In the storage device electrode 10, the elastic modulus of the lead wire 40 is desirably 50 to 150 GPa.
In the storage device electrode 10, the elastic modulus of the current collector plate 20 is desirably 150 to 250 GPa.
Moreover, in the electrode 10 for electrical storage devices, it is desirable that the Vickers hardness of the current collection board 20 is 300-500.

In the storage device electrode 10, the lead wire 40 is preferably made of at least one selected from the group consisting of nickel, copper, aluminum and brass.
These materials have high electric conductivity and are excellent as lead wire materials.
In addition, these substances can be firmly connected to stainless steel by ultrasonic welding. Therefore, the connection strength between the lead wire and the current collector plate can be sufficiently high.

In the storage device electrode 10, the lead wire 40 may be plated with at least one selected from the group consisting of nickel, gold, silver, zinc and chromium.
These materials can be rigidly connected to stainless steel by ultrasonic welding. Therefore, the connection strength between the lead wire on which these substances are plated and the current collector plate can be sufficiently high.
Moreover, a material with a low elastic modulus can be used as a core material of a lead wire, and the elastic modulus of the whole lead wire can be made low.
Furthermore, the cross-sectional shape of the lead wire is not particularly limited. Any shape such as a circle, a rectangle, or a plate can be used.

In the storage device electrode 10, it is desirable that the electrode unit 30 be made of an active material and a binder.

The active material may further contain carbon or the like, as long as it contains silicon.

The average particle size of the active material is not particularly limited, but is preferably 1 to 10 μm.
When the average particle size of the active material is 1 μm or more, the average particle size of the active material can be easily adjusted.
If the average particle size of the active material is 10 μm or less, the specific surface area is sufficiently large, so that the time required for doping can be shortened.

In the storage device electrode 10, it is preferable that the active material of the electrode unit 30 be made of only silicon.
Silicon can occlude metal ions by alloying with the metal ions.
Therefore, for example, it is possible to occlude more metal ions than a substance such as carbon which occludes metal ions by intercalation. In particular, lithium ions can store 4000 mAh / g or more.
Therefore, when the active material is made only of silicon, the electric capacity is sufficiently large.
As described above, when silicon stores a large amount of metal ions or when a large amount of metal ions are released from silicon, the volume of silicon which is an active material changes significantly. When the volume of silicon changes in this manner, wrinkles and warpage easily occur on the current collector plate.
However, in the storage device electrode of the present invention, the current collector plate is formed of austenitic stainless steel including a martensitic structure. Therefore, even if the volume of silicon changes, warpage or wrinkles are less likely to occur in the current collector plate.

Although the material of the binder of the electrode part 30 is not specifically limited, A polyimide resin, a polyamide imide resin, etc. can be mentioned. Among these, polyimide resins are preferable.
The polyimide resin is a compound which is heat resistant and strong. Therefore, when the active material is bound by a binder made of polyimide resin, the electrode portion 30 can be hardly peeled off from the current collector plate 20 even if the volume of the active material changes due to the storage and release of metal ions.

It is desirable that the weight ratio of the active material to the binder in the electrode unit 30 be 70:30 to 90:10.

The binder of the electrode unit 30 may contain a conductive aid.
The material of the conductive aid is not particularly limited, and carbon black, carbon fibers, carbon nanotubes and the like can be mentioned. Among these, carbon black is desirable.
When the binder contains a conductive additive, the conductivity of the electrode 10 for a storage battery can be increased. Therefore, current can be collected efficiently.
In particular, carbon black can ensure conductivity with a small amount. Therefore, when the carbon black is a conductive additive, the conductivity of the storage device electrode 10 can be further improved.

When the conductive additive comprises carbon black, the average particle diameter is preferably 3 to 500 nm.
In the electrode portion 30, the weight ratio of the conductive additive to the binder is preferably 20 to 50%.

Although the thickness of the electrode part 30 is not specifically limited in the electrical storage device electrode 10, it is desirable that it is 5-50 micrometers.
When the thickness of the electrode portion is less than 5 μm, the amount of the active material is smaller than that of the current collector plate, so that the electric capacity is easily reduced.
When the thickness of the electrode portion exceeds 50 μm, the size of the electricity storage device manufactured using the electrode for electricity storage device becomes large. In addition, the distance for the metal ions to move in the electrode portion becomes long, and it takes time for charging and discharging.

The areal density of the electrode unit 30 on one side is not particularly limited, but is preferably 0.1 to 10 mg / cm ² .

The storage device electrode of the present invention can be used as a positive electrode or a negative electrode of a storage device or as a metal ion supply electrode for doping metal ions in an electrolytic solution.

Next, the manufacturing method of the electrode for electrical storage devices of this invention is demonstrated.
A method of manufacturing an electrode for a storage battery device according to the present invention is a storage battery device including a current collector plate including a main body portion and a lead-out portion, an electrode portion disposed on the current collector plate, and a lead wire connected to the current collector plate. It is a manufacturing method of an electrode, and the ultrasonic connection process which connects a current collection board and a lead wire by ultrasonic welding is included.
In addition, the current collector plate is formed of an austenitic stainless steel including a martensitic structure, and the electrode portion is characterized by containing silicon as an active material.

An example of such a method for producing an electrode for a storage device of the present invention will be described in detail below.

(1) Process of producing current collector plate First, a metal plate formed of austenitic stainless steel is prepared.
Next, a current collector plate is manufactured by extending a metal plate. By this spreading process, a portion of the austenite structure is transformed to a martensitic structure.
In the spreading process, it is desirable to cold work so that the thickness is 60 to 80% of the original thickness.
Thus, a current collector plate formed of an austenitic stainless steel containing a martensitic structure can be produced.

(2) Production Process of Active Material Slurry Silicon and a binder are mixed to produce an active material slurry.
The weight ratio of the active material to the binder is not particularly limited, but it is desirable to prepare the active material: binder = 70: 30 to 90:10.

The binder is not particularly limited, and examples thereof include a polyimide resin precursor and a polyamideimide resin precursor. Among these, a polyimide resin precursor is desirable.

From the viewpoint of coatability, the viscosity of the active material slurry is desirably 1 to 10 Pa · s. The viscosity of the slurry is measured using a B-type viscometer under conditions of 1 to 10 rpm.
The viscosity of the active material slurry can be adjusted by adjusting the ratio of the active material to the binder. Moreover, you may adjust a viscosity with a thickener etc. as needed.

(3) Coating step of active material slurry The active material slurry is coated on a current collector plate.
Although the quantity of the active material slurry to apply is not specifically limited, It is desirable that it is 0.1-10 mg / cm < ² > after heat-drying.

(4) Pressing Process Next, the current collector plate coated with the active material slurry is pressed.
The pressure of the press processing is not particularly limited, but it is sufficient if it can be held down so that the active material becomes flat.

(5) Heating Step Next, the current collector plate coated with the active material slurry is heated to cure the binder contained in the active material slurry.
It is desirable to determine the heating conditions in accordance with the type of binder used.
When the binder contains a polyimide resin precursor, the heating temperature is preferably 250 to 350 ° C. Further, the atmosphere at the time of heating is desirably an inert atmosphere such as a nitrogen gas atmosphere.

(6) Ultrasonic Welding Step Next, the current collector plate and the lead wire are connected by ultrasonic welding.
When a part of the current collector plate or a part of the lead wire is melted by heat such as resistance welding to connect the current collector plate and the lead wire, the stainless steel forming the current collector plate is degraded by the heat. When such deterioration occurs, there is a problem that the function of the current collector is deteriorated.
On the other hand, ultrasonic welding is a method by which metals can be connected without generating heat. Therefore, if ultrasonic welding is used, the current collector plate and the lead wire can be connected without deteriorating the current collector plate. Therefore, thermal distortion does not occur, the strength of the lead-out portion is sufficiently strong, and the function of the current collector plate is also less likely to be deteriorated.
In addition, the time of connecting a current collection board and a lead wire by ultrasonic welding may be before arrange | positioning an active material on a current collection board.

In addition, ultrasonic welding uses, for example, an ultrasonic welding machine (2000 Xea 40: 0.8 type manufactured by Nippon Emerson Co., Ltd. Branson Division), output: 100 to 500 W, welding time: 50 to 500 milliseconds, ultrasonic horn The pressure of: can be performed under the conditions of 5 to 25 MPa.

In addition, since the desirable structure of the lead wire is already demonstrated, description here is abbreviate | omitted.

Next, a storage device using the storage device electrode of the present invention will be described.
A storage device using the storage device electrode of the present invention is also a storage device of the present invention.

The electricity storage device of the present invention is
Positive electrode,
A negative electrode,
A separator for separating the positive electrode and the negative electrode;
An electricity storage package that accommodates the positive electrode, the negative electrode, and the separator;
And the electrolytic solution enclosed in the above-mentioned storage package,
The positive electrode or the negative electrode may be the electrode for a storage device of the present invention.

In the storage device of the present invention, the lead wire of the storage device electrode of the present invention may be used to connect to another electrode, or may be used to connect to another electrical component. .

In the electricity storage device of the present invention, the negative electrode is preferably the electrode for the electricity storage device of the present invention.
Hereinafter, the electricity storage device of the present invention in which the negative electrode is an electrode for a electricity storage device of the present invention will be described.
The negative electrode is the electrode for a storage device of the present invention.
That is, the negative electrode is a current collector plate including a main body portion and a lead portion;
An electrode portion disposed on a main portion of the current collector plate,
An electrode for a storage device comprising a lead wire connected to the lead-out portion of the current collector plate,
The lead-out portion and the main body portion are formed of the same stainless steel,
Stainless steel is an austenitic stainless steel containing a martensitic structure,
The electrode portion contains silicon as an active material.
In addition, in the following description, the current collection board and silicon of the electrode for electrical storage devices of this invention are each described also as a negative electrode current collection board and a negative electrode active material.

In the storage device electrode of the present invention, the positive electrode is preferably composed of a positive electrode current collector and a positive electrode active material provided on the positive electrode current collector.
The positive electrode current collector is preferably made of aluminum, nickel, copper, silver and alloys thereof, although not particularly limited.
The positive electrode active material is not particularly limited, but LiMnO ₂ , Li _x Mn ₂ O ₄ (0 <x <2), Li ₂ MnO ₃ , Li _x Mn _1.5 Ni _0.5 O ₄ (0 <x <2) Lithium manganate having a layered structure such as lithium manganate or spinel structure; LiCoO ₂ , LiNiO ₂ or some of these transition metals replaced with another metal; LiNi _1/3 Co _1/3 Mn Lithium transition metal oxides in which specific transition metals such as _1/3 O ₂ do not exceed half; Li in excess of the stoichiometric composition in these lithium transition metal oxides; and olivine structures such as LiFePO ₄ Those that have are listed.
In addition, these metal oxides include aluminum, iron, phosphorus, titanium, silicon, lead, tin, indium, bismuth, silver, barium, calcium, mercury, palladium, platinum, tellurium, zirconium, zinc, lanthanum, etc. Material substituted may also be used. In particular, Li _α Ni _β Co _γ Al _δ O ₂ (1 ≦ α ≦ 2, β + γ + δ = 1, β ≧ 0.7, γ ≦ 0.2) or Li _α Ni _β Co _γ Mn _δ O ₂ (1 ≦ α It is desirable that ≦ 1.2, β + γ + δ = 1, β ≧ 0.6, γ ≦ 0.2).
The positive electrode active material may be used alone or in combination of two or more.

In the electricity storage device of the present invention, the separator is not particularly limited, but a porous film such as polypropylene or polyethylene or a non-woven fabric can be used. Moreover, what laminated | stacked those can also be used as a separator. Further, polyimide, polyamide imide, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), cellulose, glass fiber, which is highly heat resistant, can also be used. In addition, it is also possible to use a woven fabric separator in which the fibers are bundled and formed into a thread.

In the electricity storage device of the present invention, the electrolytic solution is not particularly limited, but a solution in which a metal salt is dissolved in a solvent as an electrolyte can be used.
As the solvent, cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC ), Linear carbonates such as dipropyl carbonate (DPC), aliphatic carboxylic acid esters such as methyl formate, methyl acetate and ethyl propionate, γ-lactones such as γ-butyrolactone, 1,2-diethoxyethane (DEE), linear ethers such as ethoxymethoxyethane (EME), cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylformium Amide, acetonitrile, propyl nitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, Examples include aprotic organic solvents such as propylene carbonate derivatives, tetrahydrofuran derivatives, ethyl ether, 1,3-propanesultone, anisole, N-methylpyrrolidone, fluorinated carboxylic acid esters and the like.
One of these may be used alone, or two or more may be mixed and used.

The metal salt is not particularly limited, and lithium salt, sodium salt, calcium salt, magnesium salt and the like can be used.
When a lithium salt is used as the metal salt, the lithium salt may be LiPF ₆ , LiAsF ₆ , LiAlCl ₄ , LiClO ₄ , LiBF ₄ , LiSbF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ CO ₃ , LiC (CF ₃ SO _{2) 2, LiN (CF 3} SO 2) 2, LiN (C 2 F 5 SO 2) 2, LiB 10 Cl 10, lower aliphatic lithium carboxylate, chloroborane lithium, lithium tetraphenylborate, LiBr, LiI, LiSCN , LiCl, imides and the like.
One of these may be used alone, or two or more may be mixed and used.

The electrolyte concentration of the electrolytic solution is not particularly limited, but is preferably 0.5 to 1.5 mol / L.
If the electrolyte concentration is less than 0.5 mol / L, it will be difficult to achieve sufficient conductivity of the electrolytic solution.
When the electrolyte concentration exceeds 1.5 mol / L, the density and viscosity of the electrolytic solution tend to increase.

An example of a method of manufacturing the electricity storage device of the present invention of such an aspect will be described.
First, a negative electrode current collector plate on which a negative electrode active material is disposed is prepared, a positive electrode current collector plate on which a positive electrode active material is disposed is prepared, and a separator is prepared.

Then, the negative electrode current collector plate and the positive electrode current collector plate are laminated with the separator interposed between the negative electrode current collector plate and the positive electrode current collector plate so that the negative electrode current collector plate and the positive electrode current collector plate are not in contact. I assume. At this time, the lead-out portion of each negative electrode current collector plate is arranged to protrude from the laminate.

Next, the lead-out portion of the negative electrode current collector plate is connected to the lead wire by ultrasonic welding. Since the connection is made by ultrasonic welding, the lead-out portion does not deteriorate due to heat and remains uniform.
The negative electrode current collector plate is made of austenitic stainless steel having a martensitic structure, and can be connected by ultrasonic welding without deteriorating the portion connected to the lead wire.
Further, the positive electrode current collector plate is also electrically connected to the lead wire. The method of electrically connecting the positive electrode current collector plate and the lead wire is not particularly limited, and may be connected by, for example, resistance welding or ultrasonic welding.

Next, the stacked body is housed in a storage package, and sealed together with an electrolytic solution in which the electrolyte is dissolved, whereby the storage device of the present invention can be manufactured.

Next, another aspect of the electricity storage device of the present invention will be described.

The electricity storage device of the present invention is
Positive electrode,
A negative electrode,
A separator for separating the positive electrode and the negative electrode;
A metal ion supply electrode for doping metal ions into the positive electrode and / or the negative electrode;
An electricity storage package that accommodates the positive electrode, the negative electrode, the separator, and the metal ion supply electrode;
And the electrolytic solution enclosed in the above-mentioned storage package,
The positive electrode, the negative electrode or the metal ion supply electrode may be the electrode for a storage device of the present invention.

Hereinafter, a case where the storage device electrode of the present invention is used as a metal ion supply electrode will be described.

When the electrode for a storage device of the present invention is used as a metal ion supply electrode, it is necessary to dope the electrode for a storage device of the present invention with metal ions.
First, a method of doping metal ions to the electrode for a storage device of the present invention will be described.

(1) Organic Electrolyte Application Step First, an organic electrolyte is applied to the electrode portion of the current collector plate of the electrode for a storage device of the present invention.
The organic electrolytic solution is not particularly limited, but a solution in which a metal salt is dissolved in an organic solvent as an electrolyte can be used.
As the organic solvent, cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC) and vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate ( Linear carbonates such as EMC), dipropyl carbonate (DPC), aliphatic carboxylic acid esters such as methyl formate, methyl acetate and ethyl propionate, γ-lactones such as γ-butyrolactone, 1,2-diethoxy Linear ethers such as ethane (DEE) and ethoxymethoxyethane (EME), cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylpho Lumamide, acetonitrile, propylnitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, Examples include aprotic organic solvents such as propylene carbonate derivatives, tetrahydrofuran derivatives, ethyl ether, 1,3-propanesultone, anisole, N-methylpyrrolidone, fluorinated carboxylic acid esters and the like.
One of these may be used alone, or two or more may be mixed and used.
When lithium is used as the metal ion source, it is desirable that the organic electrolyte have lithium ion conductivity.
(2) Heating step Next, the electrode portion coated with the organic electrolytic solution is brought into contact with a metal ion source, and heating is performed to dope metal ions.
The metal ion source is not particularly limited, and examples thereof include lithium, sodium, magnesium and calcium. Among these, lithium is desirable.
Although the conditions for heating are not particularly limited, it is desirable to heat at 250 to 300 ° C. for 10 to 120 minutes.

(3) Drying Step The electrode of the storage device after doping is washed with a solvent and naturally dried to complete the doping. As a solvent, DMC (dimethyl carbonate) can be suitably used.

In addition, the method of doping is not limited to the method of contacting such a metal ion source, Other methods can also be utilized. For example, the metal ion source and the electrode for a storage device can be connected to an external circuit and electrically doped.
In addition, although the storage device electrode of the present invention is manufactured by connecting the lead portion of the current collector plate and the lead wire by ultrasonic welding, the doping may be performed before ultrasonic welding, It may be performed after ultrasonic welding.

When the storage device electrode of the present invention is used as a metal ion supply electrode, the positive electrode in the storage device of the present invention preferably has the following configuration.
That is, it is desirable that the positive electrode be composed of a positive electrode current collector plate and a positive electrode active material provided on the positive electrode current collector plate.
The positive electrode current collector is preferably made of aluminum, nickel, copper, silver and alloys thereof, although not particularly limited.
The positive electrode active material is not particularly limited, but LiMnO ₂ , Li _x Mn ₂ O ₄ (0 <x <2), Li ₂ MnO ₃ , Li _x Mn _1.5 Ni _0.5 O ₄ (0 <x <2) Lithium manganate having a layered structure such as lithium manganate or spinel structure; LiCoO ₂ , LiNiO ₂ or some of these transition metals replaced with another metal; LiNi _1/3 Co _1/3 Mn Lithium transition metal oxides in which specific transition metals such as _1/3 O ₂ do not exceed half; Li in excess of the stoichiometric composition in these lithium transition metal oxides; and olivine structures such as LiFePO ₄ Those that have are listed.
In addition, these metal oxides include aluminum, iron, phosphorus, titanium, silicon, lead, tin, indium, bismuth, silver, barium, calcium, mercury, palladium, platinum, tellurium, zirconium, zinc, lanthanum, etc. Material substituted may also be used. In particular, Li _α Ni _β Co _γ Al _δ O ₂ (1 ≦ α ≦ 2, β + γ + δ = 1, β ≧ 0.7, γ ≦ 0.2) or Li _α Ni _β Co _γ Mn _δ O ₂ (1 ≦ α It is desirable that ≦ 1.2, β + γ + δ = 1, β ≧ 0.6, γ ≦ 0.2).
The positive electrode active material may be used alone or in combination of two or more.

When the storage device electrode of the present invention is used as a metal ion supply electrode, the negative electrode in the storage device of the present invention preferably has the following configuration.
That is, the negative electrode preferably includes a negative electrode current collector plate and an electrode portion provided on the negative electrode current collector plate, and the electrode portion preferably contains a negative electrode active material.
The negative electrode current collector plate is not particularly limited, but is preferably made of aluminum, nickel, copper, silver, an alloy thereof, or the like.
The negative electrode active material is not particularly limited, but is preferably made of silicon, silicon monoxide, silicon dioxide, carbon or the like.

When the storage device electrode of the present invention is used as a metal ion supply electrode, the separator in the storage device of the present invention is not particularly limited, but a porous film such as polypropylene or polyethylene or a non-woven fabric can be used. Moreover, what laminated | stacked those can also be used as a separator. Further, polyimide, polyamide imide, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), cellulose, glass fiber, which is highly heat resistant, can also be used. In addition, it is also possible to use a woven fabric separator in which the fibers are bundled and formed into a thread.

When the storage device electrode of the present invention is used as a metal ion supply electrode, in the storage device of the present invention, the electrolytic solution is not particularly limited, but a solution in which a metal salt is dissolved in a solvent can be used.
As the solvent, cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC ), Linear carbonates such as dipropyl carbonate (DPC), aliphatic carboxylic acid esters such as methyl formate, methyl acetate and ethyl propionate, γ-lactones such as γ-butyrolactone, 1,2-diethoxyethane (DEE), linear ethers such as ethoxymethoxyethane (EME), cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylformium Amide, acetonitrile, propyl nitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, Examples include aprotic organic solvents such as propylene carbonate derivatives, tetrahydrofuran derivatives, ethyl ether, 1,3-propanesultone, anisole, N-methylpyrrolidone, fluorinated carboxylic acid esters and the like.
One of these may be used alone, or two or more may be mixed and used.

The metal salt is not particularly limited, and lithium salt, sodium salt, calcium salt, magnesium salt and the like can be used.
When a lithium salt is used as the metal salt, the lithium salt may be LiPF ₆ , LiAsF ₆ , LiAlCl ₄ , LiClO ₄ , LiBF ₄ , LiSbF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ CO ₃ , LiC (CF ₃ SO _{2) 2, LiN (CF 3} SO 2) 2, LiN (C 2 F 5 SO 2) 2, LiB 10 Cl 10, lower aliphatic lithium carboxylate, chloroborane lithium, lithium tetraphenylborate, LiBr, LiI, LiSCN , LiCl, imides and the like.
One of these may be used alone, or two or more may be mixed and used.

The electrolyte concentration of the electrolytic solution is not particularly limited, but is preferably 0.5 to 1.5 mol / L.
If the electrolyte concentration is less than 0.5 mol / L, it will be difficult to achieve sufficient conductivity of the electrolytic solution.
When the electrolyte concentration exceeds 1.5 mol / L, the density and viscosity of the electrolytic solution tend to increase.

An example of a method of manufacturing the electricity storage device of the present invention of such an aspect will be described.
First, a positive electrode, a negative electrode and a separator are prepared.
Next, a separator is sandwiched between the positive electrode and the negative electrode so that the positive electrode and the negative electrode are not in contact, and the positive electrode and the negative electrode are stacked to form a laminate.
Separately, an electrode for a storage device of the present invention doped with metal ions, that is, a metal ion supply electrode is prepared. The lead-out portion of the metal ion supply electrode is connected in advance to a lead wire made of nickel plated copper by ultrasonic welding.

Next, the metal ion supply electrode is disposed on the outer side of the laminate, these are housed in a storage package, and sealed together with an electrolytic solution in which the electrolyte is dissolved, whereby the storage device of the present invention can be manufactured.
Further, by connecting the metal ion supply electrode and the positive electrode or the negative electrode with an external circuit, metal ions necessary for charge and discharge can be supplied to the positive electrode or the negative electrode.

The storage device electrode of the present invention can be suitably used as a positive electrode or a negative electrode of a storage device, or as a metal ion supply electrode for doping metal ions.

DESCRIPTION OF SYMBOLS 10 Storage battery device electrode 20 Current collection board 21 Lead-out | draw-out part 22 Main-body part 26 Martensite structure 27 Austenite structure 30 Electrode part 40 Lead wire

Claims (9)

A current collector consisting of a main body portion and a lead portion;
An electrode portion disposed on a main portion of the current collector plate;
An electrode for a storage device comprising a lead wire connected to the lead-out portion of the current collector plate,
The lead-out portion and the body portion are formed of the same stainless steel,
The stainless steel is an austenitic stainless steel containing a martensitic structure,
The electrode unit includes an silicon as an active material. 2. The electrode for a storage device according to claim 1, wherein in the cross section of cutting the current collector plate along the thickness direction, the martensitic structure is scattered like islands in austenite structure. The electrode for a storage device according to claim 1, wherein the lead wire has an elastic modulus smaller than that of the current collector plate. The electrode for a storage device according to any one of claims 1 to 3, wherein the lead wire is made of at least one selected from the group consisting of nickel, copper, aluminum and brass. The electrode for a storage device according to any one of claims 1 to 4, wherein the lead wire is plated with at least one selected from the group consisting of nickel, gold, silver, zinc and chromium. The electrode for a storage device according to any one of claims 1 to 5, wherein the active material is made only of silicon. The electrode for a storage device according to any one of claims 1 to 6, wherein the storage device electrode is a metal ion supply electrode for supplying a metal ion to an electrolytic solution. A storage device comprising the storage device electrode according to any one of claims 1 to 7. A current collector consisting of a main body portion and a lead portion;
An electrode portion disposed on a main portion of the current collector plate;
A manufacturing method of an electrode for an electricity storage device, comprising: a lead wire connected to the lead-out portion of the current collector plate,
An ultrasonic connection step of connecting the lead portion and the lead wire by ultrasonic welding;
The current collector plate is formed of an austenitic stainless steel containing a martensitic structure,
The method for manufacturing an electrode for a storage battery device, wherein the electrode unit contains silicon as an active material.

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