JP2009205864A - Nonaqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-aqueous electrolyte battery in which welding connectivity between a lead extraction part and a lead is improved without causing short-circuit or resistance increase of the lead taking-out part caused by falling-off of a coating agent. <P>SOLUTION: This non-aqueous electrolyte battery is equipped with: an exterior material; electrode groups laminated via separators among a plurality of positive electrodes and a plurality of negative electrodes; positive electrode leads connected to a plurality of positive electrodes; negative electrode leads connected to a plurality of negative electrodes; and a non-aqueous electrolyte housed in the exterior material. Respective positive electrodes are equipped with current collectors having current collector main bodies and the lead extraction parts integrally protruded from these main bodies, and with positive electrode layers formed at the current collector main bodies. Respective negative electrodes are equipped with the current collectors having the current collector main bodies and the lead extraction parts integrally protruded from these main bodies, and with negative electrode layers formed in the current collector main bodies. As for the lead extraction parts of the positive electrodes and the negative electrodes, contact angle against water of 20°C is 45° or less, and as for the collector main bodies, the contact angle against water of 20°C is more than 45°. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte battery.

  The rolling oil at the time of rolling remains in the aluminum foil used as a collector of the nonaqueous electrolyte battery represented by the conventional lithium ion secondary battery. When the aluminum foil as a current collector has an electrode layer formation region and an electrode layer non-formation region, and the rolling oil remains in the electrode layer non-formation region of the aluminum foil in a structure in which the electrode layer non-formation region is used for the lead extraction part Since the wettability is low, the weldability when the lead is welded to the lead take-out portion is lowered. The decrease in weldability increases the contact resistance between the lead and the current collector, and becomes an obstacle to large current characteristics.

Patent Document 1 discloses that residual rolling oil of an aluminum foil as a current collector is removed to improve the wettability of the electrode coating slurry and the aluminum foil.
Japanese Patent Laid-Open No. 2005-50679

  However, in the structure in which the aluminum foil as the current collector has the electrode layer formation region and the electrode layer non-formation region as described above, and the electrode layer non-formation region is used for the lead extraction portion, the electrode coating as in Patent Document 1 is performed. When the wettability between the working slurry and the aluminum foil is increased, the electrode coating slurry flows into a portion that originally becomes an electrode layer unformed region. As a result, there is a possibility that a short circuit or an increase in the resistance of the lead extraction portion may occur due to the dropping of the coating agent flowing into the electrode layer non-formed region (lead extraction portion).

  An object of the present invention is to provide a nonaqueous electrolyte battery having improved weld connectivity between a lead extraction part and a lead without causing a short circuit due to dropping of the coating agent or an increase in resistance of the lead extraction part. .

According to a first aspect of the present invention, an exterior material;
An electrode group having a structure in which a plurality of positive electrodes, a plurality of negative electrodes, and separators interposed between the positive electrodes and the negative electrodes are stacked in the exterior material;
A positive electrode lead connected to the plurality of positive electrodes;
A negative electrode lead connected to the plurality of negative electrodes;
Comprising a non-aqueous electrolyte housed in the exterior material,
Each of the positive electrodes is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a current collector body and a current collector having a lead extraction portion integrally projecting from the body, and the current collector body A positive electrode layer containing a positive electrode active material formed on one side or both sides, and each lead extraction part is joined and bundled by welding,
The lead extraction part of each positive electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. exceeding 45 °,
The positive electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and connected to the lead-out portions of the bundled positive electrodes by welding,
Each negative electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a current collector body and a current collector having a lead-out portion protruding integrally from the body, and the current collector body A negative electrode layer containing a negative electrode active material formed on one side or both sides of each, and each lead extraction part is joined and bundled together by welding,
The lead extraction part of each negative electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. of more than 45 °, and the negative electrode lead has a purity of 99% or more There is provided a non-aqueous electrolyte battery characterized in that it is made of aluminum or an aluminum alloy having a purity of 99% or more and is connected to the lead-out portions of the bundled negative electrodes by welding.

According to a second aspect of the present invention, an exterior material;
An electrode group having a structure in which a positive electrode, a plurality of negative electrodes, and a separator interposed between the positive electrodes and the negative electrode are wound in a spiral shape;
A positive electrode lead connected to the positive electrode;
A negative electrode lead connected to the negative electrode;
Comprising a non-aqueous electrolyte housed in the exterior material,
The positive electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a strip-shaped current collector body and a current collector having a plurality of lead extraction portions integrally projecting from the current collector body; A positive electrode layer containing a positive electrode active material formed on one side or both sides of the belt-like current collector body, and each lead extraction part is joined and bundled together by welding,
Each lead extraction part of the positive electrode has a contact angle with respect to water at 20 ° C. of 45 ° or less, and the current collector body has a contact angle with respect to water at 20 ° C. exceeding 45 °,
The positive electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and connected by welding to a plurality of lead extraction portions bundled with the positive electrode,
The negative electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a strip-shaped current collector body and a current collector having a plurality of lead extraction portions integrally projecting from the current collector body; A negative electrode layer containing a negative electrode active material formed on one side or both sides of the strip-shaped current collector body, and each lead extraction part is joined and bundled together by welding,
Each lead take-out part of the negative electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. of more than 45 °, and the negative electrode lead has a purity of 99% or more There is provided a nonaqueous electrolyte battery characterized in that it is made of aluminum or an aluminum alloy having a purity of 99% or more and is connected to a plurality of lead-out portions bundled with the negative electrode by welding.

According to a third aspect of the present invention, an exterior material;
An electrode group having a structure in which a positive electrode, a plurality of negative electrodes, and a separator interposed between the positive electrodes and the negative electrode are wound in a spiral shape;
A positive electrode lead connected to the positive electrode;
A negative electrode lead connected to the negative electrode;
Comprising a non-aqueous electrolyte housed in the exterior material,
The positive electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and takes out a strip-shaped current collector body and a strip-shaped lead integrally formed on a side surface along the longitudinal direction of the current collector body. And a positive electrode layer containing a positive electrode active material formed on one side or both sides of the band-shaped current collector body, and the lead take-out part spirals on one spiral surface of the electrode group. Protruding into a shape,
The lead lead-out part of the positive electrode has a contact angle with respect to 20 ° C. water of 45 ° or less, and the current collector body has a contact angle with respect to water of 20 ° C. exceeding 45 °,
The positive electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and is connected to a plurality of lead-out portions protruding in a spiral shape of the positive electrode by welding, and is joined and bundled by welding. A plurality of intermediate leads, and a main lead made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more and connected to the bundled intermediate leads by welding,
The negative electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and is formed on a side surface opposite to the lead-out portion of the positive electrode along the longitudinal direction of the strip-shaped current collector body and the current collector body. A current collector having an integrally formed strip-shaped lead extraction portion; and a negative electrode layer containing a negative electrode active material formed on one or both surfaces of the strip-shaped current collector body, wherein the lead extraction portion is Projecting spirally on the other spiral surface of the electrode group,
The lead extraction part of the negative electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. exceeding 45 °,
The negative electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and is connected by welding to a plurality of lead extraction portions protruding in a spiral shape of the negative electrode, and is joined and bundled by welding. A non-aqueous electrolyte battery comprising a plurality of intermediate leads and a main lead made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more and connected to the bundled intermediate leads by welding. Is provided.

  According to the present invention, a non-aqueous electrolyte battery having excellent large current characteristics with improved weld connectivity between the lead extraction part and the lead without causing a short circuit due to dropping of the coating agent or an increase in resistance of the lead extraction part. Can provide.

  Hereinafter, nonaqueous electrolyte batteries according to embodiments of the present invention will be described in detail with reference to the drawings. Each figure is a schematic diagram for promoting explanation and understanding of the invention, and its shape, dimensions, ratio, etc. are different from the actual apparatus, but these are considered in consideration of the following explanation and known techniques. The design can be changed as appropriate.

(First embodiment)
1 is a cross-sectional view of the nonaqueous electrolyte battery according to the first embodiment, FIG. 2A is a front view of a positive electrode incorporated in the nonaqueous electrolyte battery of FIG. 1, and FIG. FIG. 3 is a perspective view of an electrode group incorporated in the nonaqueous electrolyte battery of FIG. 1. FIG. 3 is a front view of the negative electrode incorporated in the nonaqueous electrolyte battery.

  The rectangular exterior material 1 is composed of, for example, a rectangular (rectangular) metal can (for example, an aluminum can) 2 that also serves as a positive electrode terminal, and a lid 3 made of, for example, aluminum that is airtightly attached to the opening of the metal can 2 by welding. Has been. The gas vent hole 4 is opened at the center of the lid 3. A metal thin film (not shown) (for example, an aluminum thin film) is attached to the back surface of the gas vent hole 4 and the lid 3 in the vicinity thereof by welding or the like, and when the gas pressure in the exterior material 1 exceeds a certain value, it breaks and gas is released. Escape to the outside of the exterior material 1. The rectangular positive terminal 5 is integrally projected from the gas vent hole 4 to, for example, the lid 3 located on the left side. The negative electrode terminal 6 having a T-shaped cross section is fitted into the rectangular insulating ring 7 of the lid 3 located on the right side, for example, from the gas vent hole 4 and is airtightly fixed.

  The rectangular laminated electrode group 8 is accommodated in the metal can 2 of the exterior material 1. The rectangular electrode group 8 includes a plurality of positive electrodes 9 shown in FIG. 2A and a plurality of negative electrodes 10 shown in FIG. 2B folded in a ninety nine as shown in FIG. The separators 11 are alternately inserted and stacked, and the end portions of the separators 11 are wound so as to cover the outer peripheral side surfaces of the rectangular columnar laminate. Such a rectangular laminated electrode group 8 is inserted and accommodated in the metal can 2 so that the surface of the separator 11 folded into a ninety-nine shape becomes the upper and lower end surfaces.

  The positive electrode 9 has a current collector 12 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil having a purity of 99% or more). The current collector 12 includes a rectangular elongated current collector main body 12a and a lead extraction portion 12b that protrudes integrally from, for example, a part of the upper left end of the current collector main body 12a. A positive electrode layer (not shown) containing the positive electrode active material is formed on one side or both sides of the current collector body 12 b of the current collector 12. In each positive electrode 9, the lead extraction portion 12 b has a property that the contact angle with respect to 20 ° C. water is 45 ° or less, and the current collector body 12 a has a property that the contact angle with respect to 20 ° C. water exceeds 45 °. Each positive electrode 9 is inserted into a bent portion of a separator 11 folded into a ninety-nine shape so that lead extraction portions 12b of the current collector 12 are arranged in the stacking direction as shown in FIG. These lead extraction portions 12b are joined and bundled together by welding.

  The negative electrode 10 includes a current collector 13 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil having a purity of 99% or more). The current collector 13 includes a rectangular elongated current collector body 13a and a lead extraction portion 13b that integrally protrudes from, for example, a part of the upper right end of the current collector body 13a. A negative electrode layer (not shown) containing the negative electrode active material is formed on one side or both sides of the current collector body 13 b of the current collector 13. In each negative electrode 10, the lead extraction portion 13 b has a property that the contact angle with respect to 20 ° C. water is 45 ° or less, and the current collector body 13 a has a property that the contact angle with respect to 20 ° C. water exceeds 45 °. Each negative electrode 10 is inserted into the bent portion of the separator 11 folded into a ninety-nine shape so that the lead extraction portion 13b of the current collector 13 is arranged in the stacking direction as shown in FIG. These lead extraction portions 13b are joined and bundled together by welding.

  A positive electrode lead 14 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more has a lower end connected to a bundled lead extraction portion 12b of a plurality of positive electrodes 9 and the other end directly below the positive electrode terminal 5. It is connected to the lower surface of the lid 3 by welding.

  A negative electrode lead 15 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more has a lower end connected to a bundled lead extraction portion 13b of a plurality of negative electrodes 10, and the other end connected to the lower surface of the lid 3. The exposed negative electrode terminal 6 is connected to the lower end surface by welding.

  In addition, laser welding, resistance welding, ultrasonic welding, etc. are mentioned as welding used for the connection of the lead extraction parts in 1st Embodiment, the connection of a lead extraction part, and a lead etc., for example.

  Hereinafter, each member of the nonaqueous electrolyte battery will be described in detail.

1) Positive electrode As described above, the positive electrode has a positive electrode active material, a conductive agent and a binder on one or both sides of a current collector body made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more. The positive electrode layer containing the structure is formed.

As the positive electrode active material, various oxides, sulfides, and the like can be used. For example, manganese dioxide (MnO ₂ ), iron oxide, copper oxide, nickel oxide, lithium manganese composite oxide (eg, Li _x Mn ₂ O ₄ or Li _x MnO ₂ ), lithium nickel composite oxide (eg, Li _x NiO ₂ ) , Lithium cobalt composite oxide (Li _x CoO ₂ ), lithium nickel cobalt composite oxide {for example, LiNi _1-yz Co _y M _z O ₂ (M is at least one element selected from the group consisting of Al, Cr and Fe) , 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 0.1}, lithium manganese cobalt composite oxide {for example, LiMn _1-yz Co _y M _z O ₂ (M is a group consisting of Al, Cr and Fe) At least one element selected), 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 0.1}, lithium manganese nickel composite compound {eg, LiMn _x Ni _x M _1-2x O ₂ (M is Co, Cr, Al) And at least one element selected from the group consisting of Fe, _1/3 ≦ x ≦ 1/2; for example, LiMn _1/3 Ni _1/3 Co _1/3 O ₂ , LiMn _1/2 Ni _1/2 O ₂ } , spinel type lithium-manganese-nickel composite oxide _{(LixMn 2-y Ni y O} 4), lithium phosphates having an olivine structure _{(Li x FePO 4, Li x} Fe 1-y Mn y PO 4, Li x CoPO 4 etc. ), Iron sulfate (Fe ₂ (SO ₄ ) ₃ ), vanadium oxide (for example, V ₂ O ₅ ), conductive polymer materials such as polyaniline and polypyrrole, disulfide-based polymer materials, sulfur (S) Organic materials such as carbon fluoride and inorganic materials can also be used, and when x, y, and z are not specified in the chemical formula, each is preferably in the range of 0 or more and 1 or less. Arbitrariness.

  More preferable active materials are lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel cobalt composite oxide, lithium manganese nickel composite compound, spinel type lithium manganese nickel composite oxide, lithium manganese cobalt composite. Examples thereof include oxides and lithium iron phosphate. By using these active materials, a high-voltage nonaqueous electrolyte battery can be obtained.

  As the conductive agent, for example, acetylene black, ketjen black, graphite, coke and the like can be used.

  As the binder, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, or the like can be used.

  The blending ratio of the active material, the conductive agent and the binder is preferably in the range of 80 to 95% by weight of the active material, 3 to 20% by weight of the conductive agent, and 2 to 7% by weight of the binder.

  The current collector is formed from a plate of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil or an aluminum alloy foil). The current collector is particularly preferably JIS H 0001 aluminum foil. Since such an aluminum foil is hard and has little deformation at the time of processing, for example, it can be wound together with a positive electrode and a separator to suppress deformation when manufacturing a spiral electrode group, thereby reducing yield reduction such as short circuit. Is possible.

  The average crystal grain size of the aluminum foil and the aluminum alloy foil is 50 μm or less, more preferably 30 μm or less, and further preferably 5 μm or less. By making the average crystal grain size 50 μm or less, the strength of the aluminum foil or aluminum alloy foil can be drastically increased, so that the positive electrode can be densified with a high press pressure, and the battery capacity can be increased. Can be increased.

  The average crystal grain size is determined as follows. The structure of the current collector surface is observed with an optical microscope, and the number n of crystal grains existing within 1 mm × 1 mm is determined. Using this n, the average crystal grain area S is determined from S = 1 × 10 6 / n (μm 2). The average crystal particle diameter d (μm) is calculated from the obtained S value by the following formula (A).

d = 2 (S / π) ^1/2 (A)
The average crystal grain size of the aluminum foil and aluminum alloy foil changes under complex influences from a plurality of factors such as material structure, impurities, processing conditions, heat treatment history, and annealing conditions. The crystal grain size can be adjusted by combining the above factors in the production process of the current collector.

  The thickness of the aluminum foil and the aluminum alloy foil is 20 μm or less, more preferably 15 μm or less. The aluminum alloy is preferably an alloy containing elements such as magnesium, zinc, and silicon. On the other hand, when a transition metal such as iron, copper, nickel, or chromium is included in the alloy, its content is 1% by weight or less.

  In the current collector of the positive electrode, the current collector body (positive electrode layer forming region) has a contact angle with respect to 20 ° C. water of 45 ° or less, and the lead extraction part (positive electrode layer non-formed region) has a contact angle with respect to 20 ° C. water of 45 °. Shows properties exceeding °.

Here, as shown in FIG. 12, 0.1 ml of pure water (temperature 20 ° C.) is dropped on an aluminum foil (or aluminum alloy foil) 61 as a current collector, and the water droplet 62 and the aluminum foil 61 are in contact with each other. A straight line 63 connecting the contact point P1 and the apex P2 of the water drop 62 is drawn, an angle θ _B formed by the straight line 63 and the surface of the aluminum foil 61 is measured, and an angle twice this angle θ _B is measured with the surface of the aluminum foil 61. An angle θ _A (contact angle) formed by the tangent line 64 of the water droplet 62 can be obtained. The contact angle of the lead extraction part of the current collector can be measured by taking out the positive electrode from the battery and cutting out the lead extraction part exposed from the positive electrode. On the other hand, the contact angle of the current collector body of the current collector can be measured from the current collector body after the positive electrode is taken out from the battery and the positive electrode layer is removed.

  The contact angle of the lead extraction part of the current collector with respect to 20 ° C. water is preferably 30 ° or less, more preferably 20 ° or less. The contact angle of the current collector body with respect to 20 ° C. water is preferably 60 ° or more, more preferably 90 ° or more.

  A positive electrode including a current collector having such a lead take-out portion having a contact angle with respect to 20 ° C. water of 45 ° or less and a current collector body having a contact angle with respect to 20 ° C. water exceeding 45 ° is, for example, as follows: Can be produced by a simple method.

  First, a positive electrode active material, a binder and a conductive agent are suspended in an appropriate solvent to prepare a coating slurry. This coating slurry is applied to one or both sides of a current collector body, that is, a current collector excluding a lead extraction portion, of a current collector made of an aluminum foil having a purity of 99% or more or an aluminum alloy foil having a purity of 99% or more. And drying to form a positive electrode layer. Subsequently, after the current collector on which the positive electrode layer is formed is placed in, for example, a holder in the chamber of the atmospheric pressure plasma apparatus, plasma is generated in the chamber in the atmospheric pressure atmosphere by supplying high-frequency power. At this time, the exposed lead extraction portion of the current collector is exposed to plasma, and the rolling oil on the surface is removed.

  In the positive electrode obtained by such a method, the lead extraction part of the current collector has a property that the contact angle with water at 20 ° C. is 45 ° or less by removing the rolling oil, and the current collector body of the current collector is made of the rolling oil. The contact angle with respect to water at 20 ° C. exceeds 45 ° while remaining.

3) Negative electrode As described above, the negative electrode is made of an aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more. Thus, a negative electrode layer containing a conductive agent is formed.

  The negative electrode active material is not limited, but is preferably a lithium compound that occludes and releases lithium ions at a potential of 0.4 V vs Li / Li + or higher.

  As the lithium compound, for example, lithium oxide, lithium sulfide, lithium nitride, or the like can be used. These include compounds that do not contain lithium in an uncharged state, but that contain lithium upon charging.

Examples of the lithium oxide include titanium-containing metal composite oxides, amorphous tin oxides such as SnB _0.4 P _0.6 O _3.1 , tin silicon oxides such as SnSiO ₃ , silicon oxides such as SiO, tungsten oxides such as WO ₃ and the like. Can be used. Of these, titanium-containing metal composite oxides are preferable.

As the titanium-containing metal composite oxide, for example, lithium titanium oxide, titanium-based oxide not containing lithium, or the like can be used when the oxide is synthesized. Examples of the lithium titanium oxide include lithium titanate having a spinel structure and lithium titanate having a ramsdellite structure. Examples of the lithium titanate having a spinel structure include Li _{4 + x} Ti ₅ O ₁₂ (x varies within a range of −1 ≦ x ≦ 3 due to a charge / discharge reaction). Examples of the lithium titanate having a ramsdellite structure include Li _{2 + y} Ti ₃ O ₇ (y changes within a range of −1 ≦ y ≦ 3 due to a charge / discharge reaction). Examples of the titanium-based oxide include metal composite oxides containing at least one element selected from the group consisting of TiO ₂ , Ti and P, V, Sn, Cu, Ni, and Fe. TiO ₂ is preferably anatase type and low crystalline having a heat treatment temperature of 300 to 500 ° C. The metal composite oxide containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni and Fe is, for example, TiO ₂ —P ₂ O ₅ , TiO ₂ —V ₂ O ₅ , TiO. _2- P ₂ O ₅ —SnO ₂ , TiO ₂ —P ₂ O ₅ —MeO (Me is at least one element selected from the group consisting of Cu, Ni and Fe) and the like can be used. The metal composite oxide preferably has a low crystallinity and has a microstructure in which a crystal phase and an amorphous phase coexist or exist alone. Such a microstructured metal composite oxide can greatly improve the cycle performance. Among these, lithium titanium oxide, metal composite oxide containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni, and Fe are preferable. In such a metal composite oxide, the value of the molar ratio of oxygen can be changed by the influence of oxygen non-stoichiometry or the like.

Examples of the sulfide include titanium sulfide such as TiS ₂ , molybdenum sulfide such as MoS _2, and iron sulfide such as FeS, FeS ₂ , and Li _x FeS ₂ .

Examples of the nitride include lithium cobalt nitride (for example, Li _x Co _y N, 0 <x <4, 0 <y <0.5).

Among these active materials, it is preferable to include one selected from lithium titanate having a spinel structure such as Li _{4 + x} Ti ₅ O ₁₂ , FeS, and FeS ₂ , and the most preferable active material is a spinel structure. Lithium titanate having

  As the binder, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, styrene-butadiene rubber, or the like can be used.

  Examples of the conductive agent include carbon black such as acetylene black and ketjen black, graphite, coke, carbon fiber, and metal powder.

  The mixing ratio of the active material, the binder and the conductive agent is preferably in the range of 80 to 98% by weight of the active material, 2 to 7% by weight of the binder, and 0 to 20% by weight of the conductive agent.

  The current collector is formed from a plate of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil or an aluminum alloy foil). The current collector is particularly preferably JIS H 0001 aluminum foil. Since such an aluminum foil is hard and has little deformation at the time of processing, for example, it can be wound together with a positive electrode and a separator to suppress deformation when manufacturing a spiral electrode group, thereby reducing yield reduction such as short circuit. Is possible.

  The aluminum foil or aluminum alloy foil preferably has an average crystal grain size of 50 μm or less. Since aluminum foil or aluminum alloy foil having such an average crystal grain size can dramatically increase the strength, it becomes possible to increase the density of the negative electrode with a high press pressure and increase the battery capacity. In addition, since the current collector can be prevented from melting and corroding in an overdischarge cycle under a high temperature environment (40 ° C. or higher), an increase in negative electrode impedance can be suppressed. Furthermore, output characteristics, quick charge, and charge / discharge cycle characteristics can also be improved. A more preferable average crystal grain size is 30 μm or less, and further preferably 5 μm or less. The average crystal grain size is determined by the same method as described for the positive electrode.

  The thickness of the aluminum foil or aluminum alloy foil is desirably 20 μm or less, more preferably 15 μm or less.

  In the negative electrode current collector, the current collector body (negative electrode layer forming region) has a contact angle with water of 20 ° C. of 45 ° or less, and the lead extraction part (negative electrode layer non-formed region) has a contact angle with water of 20 ° C. of 45 °. Shows properties exceeding °.

  Here, the contact angle can be obtained by the same method as described for the positive electrode. The contact angle of the lead extraction part of the current collector can be measured by taking out the negative electrode from the battery and cutting out the lead extraction part exposed from the negative electrode. On the other hand, the contact angle of the current collector body of the current collector can be measured from the current collector body after the negative electrode is taken out from the battery and the negative electrode layer is removed.

  The contact angle of the lead extraction part of the current collector with respect to 20 ° C. water is preferably 30 ° or less, more preferably 20 ° or less. The contact angle of the current collector body with respect to 20 ° C. water is preferably 60 ° or more, more preferably 90 ° or more.

  The negative electrode provided with the current collector having such a lead take-out portion with a contact angle with respect to 20 ° C. water of 45 ° or less and a current collector body with a contact angle with respect to 20 ° C. water exceeding 45 ° is, for example, as follows: Can be produced by a simple method.

  First, a negative electrode active material, a binder and, if necessary, a conductive agent are suspended in a suitable solvent to prepare a coating slurry. This coating slurry is applied to one or both sides of a current collector body, that is, a current collector excluding a lead extraction portion, of a current collector made of an aluminum foil having a purity of 99% or more or an aluminum alloy foil having a purity of 99% or more. And dried to form a negative electrode layer. Subsequently, after the current collector on which the negative electrode layer is formed is placed in, for example, a holder in the chamber of the atmospheric pressure plasma apparatus, plasma is generated in the atmospheric pressure chamber by supplying high-frequency power. At this time, the exposed lead extraction portion of the current collector is exposed to plasma, and the rolling oil on the surface is removed.

  In the negative electrode obtained by such a method, the lead extraction part of the current collector has a property that the contact angle with water at 20 ° C. is 45 ° or less by removing the rolling oil, and the current collector body of the current collector is made of the rolling oil. The contact angle with respect to water at 20 ° C. exceeds 45 ° while remaining.

4) Separator As the separator, for example, a porous film or a non-woven fabric obtained from a polymer such as polyolefin, cellulose, polyethylene terephthalate, or vinylon is used. Here, the material of the separator is selected from one type or a combination of two or more types. In particular, a nonwoven fabric made of any of polyolefin, cellulose, polyethylene terephthalate, and vinylon is preferable.

5) Nonaqueous electrolyte This nonaqueous electrolyte contains a nonaqueous solvent and an electrolyte salt dissolved in the nonaqueous solvent. Further, the non-aqueous solvent may contain a polymer.

Examples of the electrolyte salt include LiPF ₆ , LiBF ₄ , Li (CF ₃ SO ₂ ) ₂ N (bistrifluoromethanesulfonylamide lithium; commonly known as LiTFSI), LiCF ₃ SO ₃ (commonly known as LiTFS), and Li (C ₂ F ₅ SO ₂ ). ₂ N (bis pentafluoroethanesulfonyl amide lithium; called _{LiBETI), LiClO 4, LiAsF 6} , LiSbF 6, bisoxalato Lato lithium borate _{(LiB (C 2 O 4)} 2 ( known as LiBOB)), difluoro (tri-fluoro-2 - oxide-2-trifluoromethyl - methylpropionate diisocyanatohexane (2 -) - 0,0) lithium borate _{(LiBF2 (OCOOC (CF 3)} 2) ( aka LiBF ₂ (HHIB))) include lithium salts and the like. These electrolyte salts may be used alone or in combination of two or more. Particularly preferred are LiPF ₆ and LiBF ₄ .

  The electrolyte salt concentration is preferably 1.5M or more and 3M or less. Such regulation of the electrolyte concentration makes it possible to further improve the performance when a high load current is passed while suppressing the influence of an increase in viscosity due to an increase in the electrolyte salt concentration.

  The non-aqueous solvent is not particularly limited, but propylene carbonate (PC), ethylene carbonate (EC), 1,2-dimethoxyethane (DME), γ-butyrolactone (GBL), tetrahydrofuran (THF), 2- Use methyltetrahydrofuran (2-MeHF), 1,3-dioxolane, sulfolane, acetonitrile (AN), diethyl carbonate (DEC), dimethyl carbonate (DMC), methyl ethyl carbonate (MEC), dipropyl carbonate (DPC), etc. Can do. These solvents may be used alone or in combination of two or more. Of these, γ-butyrolactone is preferred. When two or more kinds of solvents are combined, it is preferable to select from all solvents having a dielectric constant of 20 or more.

  An additive may be added to the non-aqueous electrolyte. Although an additive is not specifically limited, Vinylene carbonate (VC), vinylene acetate (VA), vinylene butyrate, vinylene hexanate, vinylene crotonate, catechol carbonate, etc. are mentioned. The concentration of the additive is 0.1% by weight or more and 3% by weight or less, more preferably 0.5% by weight or more and 1% by weight or less in terms of external ratio with respect to the nonaqueous electrolyte.

  As described above, according to the first embodiment, in the current collector 12 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more of the plurality of positive electrodes 9 incorporated in the stacked electrode group 8 shown in FIGS. Welding for joining the lead extraction portions 12b of the positive electrodes 9 together and bundling them by making the plurality of lead extraction portions 12b have a property that the contact angle with water at 20 ° C. is 45 ° or less, that is, a property showing high wettability. Can improve connectivity. Further, the connectivity of the bundled lead extraction portion 12b and the positive electrode lead 14 by welding can be improved.

  Similarly, in the current collector 13 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more of the plurality of negative electrodes 10 incorporated in the laminated electrode group 8, the contact angle of the lead extraction portion 13b with respect to water at 20 ° C. is 45. By making the following properties, that is, properties exhibiting high wettability, the connectivity by welding for joining and bundling a plurality of lead extraction portions 13b to each other, welding of the bundled lead extraction portions 13b and the negative electrode lead 15 Connectivity can be improved.

  Therefore, in the structure in which the leads 14 and 15 are connected to the plurality of positive electrodes 9 and negative electrodes 10, the contact angle of the lead extraction portions 12b and 13b of the current collectors 12 and 13 with respect to 20 ° C. water is 45 ° or less. Therefore, the connectivity between the plurality of lead extraction portions can be improved, and the connectivity between the bundled lead extraction portions and the leads can be improved, so that it is possible to provide a nonaqueous electrolytic battery with excellent large current characteristics.

  In addition, according to the first embodiment, the current collector 12 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more of the plurality of positive electrodes 9 incorporated in the laminated electrode group 8 is formed with a positive electrode layer. When applying the coating slurry containing the positive electrode active material to the current collector main body 12a by making the current main body 12a have a contact angle with water at 20 ° C. exceeding 45 °, that is, a property having poor wettability, The coating slurry can be suppressed or prevented from flowing into the lead extraction portion 12b, which is the positive electrode layer non-formation region of the current collector 12.

  Similarly, in the current collector 13 made of aluminum having a purity of 99% or more of the plurality of negative electrodes 10 or an aluminum alloy having a purity of 99% or more, the current collector body 13a on which the negative electrode layer is formed has a contact angle of 45 ° C. with respect to water at 20 ° C. When the coating slurry containing the negative electrode active material is applied to the current collector main body 13a by setting the property to exceed °, that is, the property having poor wettability, the negative electrode layer unformed region of the current collector 13 is applied to the current collector body 13a. It is possible to suppress or prevent the flow (protruding) into the lead extraction portion 13b.

  As a result, it is possible to prevent a short circuit or an increase in the resistance of the lead extraction part due to the dropping of the coating agent flowing into the lead extraction parts 12b and 13b of the positive electrode 9 and the negative electrode 10, thereby greatly contributing to the improvement of the yield of the nonaqueous electrolyte battery. .

In particular, in the negative electrode 10 having a negative electrode layer containing a negative electrode active material having a lithium occlusion potential of 0.4 V vs Li / Li ⁺ or higher, the current collector 13 made of aluminum having a purity of 99% or higher or an aluminum alloy having a purity of 99% or higher is used. A non-aqueous electrolyte battery with reduced self-discharge by exposing the lead extraction part 13b to a plasma atmosphere or the like, removing residual rolling oil on the surface thereof, and setting the contact angle to water at 20 ° C. to 45 ° or less. Can be obtained.

That is, the rolling oil at the time of rolling remains in the aluminum foil used as the current collector of the conventional nonaqueous electrolyte battery. This rolling oil is decomposed at the time of charging at a positive electrode potential of a general lithium ion secondary battery, but in a negative electrode containing a negative electrode active material having a lithium occlusion potential of 0.4 V vs Li / Li ⁺ or more, the decomposition reaction of the rolling oil is performed. Does not occur and remains as it is. When this residual rolling oil is present in the lead extraction portion, which is the negative electrode layer-unformed region of the aluminum foil current collector, self-discharge is promoted. For this reason, the lead extraction part 13b of the current collector 13 is exposed to a plasma atmosphere or the like to remove residual rolling oil on the surface, and the contact angle with respect to 20 ° C. water is set to 45 ° or less. In addition, a highly reliable nonaqueous electrolyte battery with reduced self-discharge can be provided.

  In the nonaqueous electrolyte battery according to the first embodiment shown in FIG. 1 to FIG. 3 described above, the laminated electrode group is not limited to a form using a 99-fold separator, and a plurality of rectangular separators, for example, are provided. You may laminate | stack between the positive electrode of a sheet, and a negative electrode.

(Second Embodiment)
4 is a cross-sectional view showing a nonaqueous electrolyte battery according to the second embodiment, FIG. 5A is a development view of a positive electrode incorporated in the nonaqueous electrolyte battery of FIG. 4, and FIG. 4 is a developed view of the negative electrode incorporated in the nonaqueous electrolyte battery 4, FIG. 6 is a top view of the electrode group incorporated in the nonaqueous electrolyte battery of FIG. 4, and FIG. It is a figure explaining the positional relationship of the several lead extraction part of the expand | deployed negative electrode for arranging.

  The rectangular packaging material 21 includes, for example, a rectangular (rectangular) metal can (for example, an aluminum can) 22 that also serves as a positive electrode terminal, and a lid 23 made of, for example, aluminum that is airtightly attached to the opening of the metal can 22 by welding. Has been. The gas vent hole 24 is opened at the center of the lid body 23. A metal thin film (not shown) (for example, an aluminum thin film) is attached to the back surface of the gas vent hole 24 and the lid 23 in the vicinity thereof by welding or the like, and when the gas pressure in the exterior material 21 exceeds a certain value, it breaks and gas is released. Escape to the outside of the exterior material 21. The rectangular positive terminal 25 is integrally projected from the gas vent hole 24 to, for example, a lid body 23 located on the left side. The negative electrode terminal 26 having a T-shaped cross section is fitted into a rectangular insulating ring 27 of the lid body 23 located, for example, on the right side from the gas vent hole 24 and is airtightly fixed.

  The flat spiral electrode group 28 is accommodated in a metal can 22 of the exterior material 21. The flat spiral electrode group 28 includes a belt-like positive electrode 29 shown in FIG. 5 (A) and a belt-like negative electrode 30 shown in FIG. 5 (B) spirally through a belt-like separator 31 as shown in FIG. It has a structure that is wound and press-molded to make it flat. Such a flat spiral electrode group 28 is inserted and accommodated in the metal can 22 so that the spiral surfaces are the upper and lower end surfaces.

  The positive electrode 29 has a current collector 32 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil having a purity of 99% or more). The current collector 32 includes a strip-shaped current collector main body 32a and a plurality of strip-shaped lead extraction portions 32b that protrude integrally from the current collector main body 32a. A positive electrode layer (not shown) containing the positive electrode active material is formed on one side or both sides of the current collector body 32 b of the current collector 32. In the positive electrode 29, the plurality of lead extraction portions 32b have a property that the contact angle with respect to 20 ° C. water is 45 ° or less, preferably 30 ° or less, more preferably 20 ° or less. The current collector body 32a has a property that the contact angle with respect to 20 ° C. water exceeds 45 °, preferably 60 ° or more, more preferably 90 ° or more. Each lead mounting portion 32b of the positive electrode 29 is set in a direction perpendicular to the direction of the straight portion of the flat spiral electrode group 28 as shown in FIG. Arranged side by side. These lead extraction portions 32b are bundled together by welding.

  The negative electrode 30 includes a current collector 33 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil having a purity of 99% or more). The current collector 33 is composed of a strip-shaped current collector body 33a and a plurality of strip-shaped lead extraction portions 33b that protrude integrally from the current collector body 33a. A negative electrode layer (not shown) containing the negative electrode active material is formed on one side or both sides of the current collector body 33 b of the current collector 33. In the negative electrode 30, the plurality of lead extraction portions 33 b have a property that the contact angle with respect to 20 ° C. water is 45 ° or less, preferably 30 ° or less, more preferably 20 ° or less. The current collector body 33a has a property that the contact angle with respect to 20 ° C. water exceeds 45 °, preferably 60 ° or more, and more preferably 90 ° or more. Each negative electrode lead mounting portion 33b is set in a direction perpendicular to the direction of the straight portion of the flat spiral electrode group 28 as shown in FIG. Arranged side by side. These lead extraction portions 33b are joined and bundled together by welding.

Next, the position setting of the plurality of lead extraction portions will be described in detail. For example, paying attention to a plurality of lead extraction portions 33b of the negative electrode 30 arranged side by side in a direction perpendicular to the direction of the straight portion of the flat spiral electrode group 29, the winding start and end of the winding in the flat spiral electrode group 29 are focused. Assuming that the positions toward S1 are S1, S2, S3, S4, and S5, the positional relationship of each lead extraction portion 33b can be calculated from FIG. 7 showing the developed negative electrode. In other words, when the plurality of lead extraction portions 33b are positioned at the straight line portion (length L) of the flat spiral electrode group 29, between the arbitrary points (between L ₁ and L ₂ , where L ₁ + L _2). = L, L ₁ ≠ L ₂ ).

As shown in FIG. 7, the distance between the position S1 of the lead extraction portion 33b on the winding start side and the position S2 of the lead extraction portion 33b adjacent to the winding end side is L ₂ + (D _n π) / 2 + L ₂ . It can be calculated from the formula. Here, D _n is the total thickness when the negative electrode is wound from the beginning of winding to position S2. The distance between the positions S2 and S3 is an expression of L ₁ + (D _{n + 1} π) / 2 + L ₁ , and the distance between the positions S3 and S4 is an expression of L ₂ + (D _{n + 2} π) / 2 + L ₂ , S4 and S5 Can be calculated from the formula L ₁ + (D _{n + 3} π) / 2 + L ₁ , respectively. Here, D _{n + 1} , D _{n + 2} and D _{n + 3} are total thicknesses when the negative electrode is wound from the beginning of winding to position S3, position S4 and position S5, respectively.

  By determining the positions (intervals of the lead extraction portions 33b) of the plurality of lead extraction portions 33b integrally projecting from the strip-shaped current collector main body 33a based on such a formula, the plurality of lead extraction portions 33b are determined. As shown in FIG. 6, the flat spiral electrode group 29 can be arranged side by side in a direction perpendicular to the direction of the straight portion.

  Similarly, with respect to the positive electrode, by determining the positions of the plurality of lead extraction portions 32b that integrally project from the strip-shaped current collector body 32a (intervals between the lead extraction portions 32b), the plurality of lead extraction portions 32b are determined. As shown in FIG. 6, the flat spiral electrode group 29 can be arranged side by side in a direction perpendicular to the direction of the straight portion.

  The positive electrode lead 34 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more has its lower end connected to a plurality of lead extraction portions 32b bundled with the positive electrode 29 by welding and the other end directly below the positive electrode terminal 25. The lid 23 is connected to the lower surface by welding.

  A negative electrode lead 35 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more has its lower end connected to a plurality of lead extraction portions 33b bundled with the negative electrode 10 by welding and the other end to the lower surface of the lid 23. The exposed negative electrode terminal 26 is connected to the lower end surface by welding.

  In addition, laser welding, resistance welding, ultrasonic welding, etc. are mentioned as welding used for the connection of the lead extraction parts in 2nd Embodiment, the connection of a lead extraction part, and a lead etc., for example.

  The details of each member of the nonaqueous electrolyte battery are the same as those described in the first embodiment.

  A positive electrode including a current collector having a plurality of strip-shaped lead extraction portions having a contact angle with respect to 20 ° C. water of 45 ° or less and a strip-shaped current collector body having a contact angle with respect to 20 ° C. water exceeding 45 ° is, for example, It can be produced by the following method.

  First, a positive electrode active material, a binder and a conductive agent are suspended in an appropriate solvent to prepare a coating slurry. Of the current collector made of an aluminum foil having a purity of 99% or more or an aluminum alloy foil having a purity of 99% or more, this coating slurry is a strip-shaped current collector body, that is, one side of the current collector excluding a plurality of lead extraction portions or It is applied on both sides and dried to form a positive electrode layer. Subsequently, after the current collector on which the positive electrode layer is formed is placed in, for example, a holder in the chamber of the atmospheric pressure plasma apparatus, plasma is generated in the chamber in the atmospheric pressure atmosphere by supplying high-frequency power. At this time, the exposed plurality of lead extraction portions of the current collector are exposed to plasma, and the rolling oil on the surface is removed.

  In the positive electrode obtained by such a method, the multiple lead extraction part of the current collector has a property that the contact angle with water at 20 ° C. is 45 ° or less by removing the rolling oil, and the current collector main body of the current collector is the rolling oil The contact angle with respect to water at 20 ° C. exceeds 45 °.

  A negative electrode including a current collector having a plurality of lead take-out portions having a contact angle with respect to 20 ° C. water of 45 ° or less and a current collector body having a contact angle with respect to 20 ° C. water exceeding 45 ° is, for example, It can produce by such a method.

  First, a negative electrode active material, a binder and, if necessary, a conductive agent are suspended in a suitable solvent to prepare a coating slurry. This coating slurry is applied to one or both sides of a strip-shaped current collector body of an aluminum foil having a purity of 99% or more or an aluminum alloy foil having a purity of 99% or more, that is, a current collector excluding a plurality of lead extraction portions. It is applied and dried to form a negative electrode layer. Subsequently, after the current collector on which the negative electrode layer is formed is placed in, for example, a holder in the chamber of the atmospheric pressure plasma apparatus, plasma is generated in the atmospheric pressure chamber by supplying high-frequency power. At this time, the exposed plurality of lead extraction portions of the current collector are exposed to plasma, and the rolling oil on the surface is removed.

  In the negative electrode obtained by such a method, the lead extraction part of the current collector has a property that the contact angle with water at 20 ° C. is 45 ° or less by removing the rolling oil, and the current collector body of the current collector is made of the rolling oil. The contact angle with respect to water at 20 ° C. exceeds 45 ° while remaining.

  As described above, according to the second embodiment, a plurality of current collectors 32 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more of the positive electrode 29 incorporated in the flat spiral electrode group 28 shown in FIGS. By making the lead lead-out portion 32b have a contact angle with water at 20 ° C. of 45 ° or less, that is, a property showing high wettability, the lead lead-out portions 12b of the positive electrode 29 are joined to each other by welding to bind them together. Connectivity can be improved. Further, the connectivity of the bundled lead extraction portion 32b and the positive electrode lead 34 by welding can be improved.

  Similarly, in a current collector 33 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more of the negative electrode 30 incorporated in the flat spiral electrode group 28, the contact angle of the plurality of lead extraction portions 33b with respect to water at 20 ° C. Of 45 ° or less, that is, a property exhibiting high wettability, so that a plurality of lead take-out portions 33b are joined by welding to bind them together, and the bundled lead take-out portions 33b and the negative electrode lead 35 Connectivity by welding can be improved.

  Accordingly, in the current collectors 32 and 33 of the positive electrode 29 and the negative electrode 30, a plurality of strip-shaped lead extraction portions 32b and 33b are integrally projected from the strip-shaped current collector main bodies 32a and 33a, and the leads 34 and 35 are formed in the lead extraction portion. In the multi-point connection structure for connecting the plurality of lead extraction portions, the contact angle of the plurality of lead extraction portions 32b and 33b of the current collectors 32 and 33 with respect to 20 ° C. water is 45 ° or less. Since the connectivity can be improved and the connectivity between the bundled lead extraction portion and the leads can be improved, a non-aqueous electrolytic battery having excellent large current characteristics can be provided.

  Further, the current collector main body 32a on which the positive electrode layer is formed and the current collector main body 33b on which the negative electrode layer is formed are described in the first embodiment by making the contact angle with respect to water at 20 ° C. exceed 45 °. In the same manner as described above, it is possible to suppress or prevent the coating slurry from flowing into the lead take-out portions 32b and 33b of the positive electrode 29 and the negative electrode 30 in the step of applying the coating slurry, thereby preventing the coating agent from falling off. Since the resulting short circuit or increase in resistance of the lead extraction portion can be prevented, it can greatly contribute to the improvement of the yield of the nonaqueous electrolyte battery.

In particular, in the negative electrode 30 having a negative electrode layer containing a negative electrode active material having a lithium occlusion potential of 0.4 V vs Li / Li ⁺ or higher, the current collector 33 made of aluminum having a purity of 99% or higher or an aluminum alloy having a purity of 99% or higher is used. As described in the first embodiment, the lead extraction part 33b is exposed to a plasma atmosphere or the like, and the residual rolling oil on the surface is removed so that the contact angle with respect to 20 ° C. water is 45 ° or less. Similarly, a nonaqueous electrolyte battery with reduced self-discharge can be obtained.

(Third embodiment)
8 is a cross-sectional view showing a nonaqueous electrolyte battery according to the third embodiment, FIG. 9A is a development view of a negative electrode incorporated in the nonaqueous electrolyte battery of FIG. 8, and FIG. 9B is a diagram. FIG. 10 is a developed view of the positive electrode incorporated in the nonaqueous electrolyte battery of FIG. 8, and FIG. 10 is a perspective view of the flat spiral electrode group incorporated in the nonaqueous electrolyte battery of FIG.

  The rectangular exterior member 41 includes, for example, a rectangular (square) metal can (for example, an aluminum can) 42 that also serves as a positive electrode terminal, and a lid 43 made of, for example, aluminum that is airtightly attached to the opening of the metal can 42 by welding. Has been. The gas vent hole 44 is opened at the center of the lid body 43. A metal thin film (not shown) (for example, an aluminum thin film) is attached to the back surface of the gas vent hole 44 and the lid 43 in the vicinity thereof by welding or the like, and when the gas pressure in the exterior material 41 exceeds a certain value, it breaks and gas is released. Escape to the outside of the exterior material 41. The rectangular positive terminal 45 is integrally projected from the gas vent hole 44 to, for example, a lid body 43 located on the left side. The negative electrode terminal 46 having a T-shaped cross section is fitted into a rectangular insulating ring 47 of the lid body 43 located on the right side from the gas vent hole 44 and fixed in an airtight manner.

  The flat spiral electrode group 48 is accommodated in a metal can 42 of the exterior material 41. The flat spiral electrode group 48 is formed by winding a belt-like positive electrode 49 shown in FIG. 9B and a belt-like negative electrode 50 shown in FIG. 9A in a spiral shape via a belt-like separator (not shown). , Has a flat structure by press molding. Such a flat spiral electrode group 48 is inserted and accommodated in the metal can 42 so that the spiral surfaces are the upper and lower end surfaces.

  The positive electrode 49 includes a current collector 51 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil having a purity of 99% or more). The current collector 51 includes a belt-shaped current collector main body 51a and a belt-shaped lead extraction portion 51b formed integrally on a side surface along the longitudinal direction of the current collector main body 51a. A positive electrode layer (not shown) containing the positive electrode active material is formed on one side or both sides of the current collector body 51 b of the current collector 51. As shown in FIG. 10, the lead extraction portion 51 b protrudes spirally from one spiral surface of the flat spiral electrode group 48 (the surface on the bottom side of the metal can 42 in the state accommodated in the metal can 42). Yes. In the positive electrode 49, the lead extraction portion 51b protruding in a spiral shape has a property that the contact angle with respect to 20 ° C. water is 45 ° or less, preferably 30 ° or less, more preferably 20 ° or less. The current collector main body 51a has a property that the contact angle with respect to water at 20 ° C. exceeds 45 °, preferably 60 ° or more, more preferably 90 ° or more.

  The negative electrode 50 includes a current collector 52 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more (for example, an aluminum foil having a purity of 99% or more). The current collector 52 includes a strip-shaped current collector main body 52a and a strip-shaped lead extraction integrally formed on the side surface opposite to the lead extraction portion 51b of the positive electrode 49 along the longitudinal direction of the current collector main body 52a. Part 52b. A negative electrode layer (not shown) containing the negative electrode active material is formed on one side or both sides of the current collector body 52 b of the current collector 52. As shown in FIG. 10, the lead extraction part 52 b spirally projects from the other spiral surface of the flat spiral electrode group 48 (the surface on the lid 43 side in the state accommodated in the metal can 42). In the negative electrode 50, the lead extraction portion 52b protruding in a spiral shape has a property that the contact angle with respect to water at 20 ° C. is 45 ° or less, preferably 30 ° or less, more preferably 20 ° or less. The current collector main body 52a has a property that the contact angle with respect to water at 20 ° C. exceeds 45 °, preferably 60 ° or more, more preferably 90 ° or more.

  A plurality of positive intermediate leads 53 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more are connected to a plurality of portions of lead extraction portions 51b protruding in a spiral shape of the positive electrode 49 by welding. These positive intermediate leads 53 are bundled together by welding. The positive electrode main lead 54 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more is connected to the positive electrode intermediate lead 53 having one end bundled by resistance welding, and the other end is welded to the bottom inner surface of the metal can 42 by welding. It is connected. The plurality of positive intermediate leads 53 and positive main leads 54 constitute a positive lead.

  A plurality of negative electrode intermediate leads 55 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more are connected to a plurality of portions of lead extraction portions 52b protruding in a spiral shape of the negative electrode 50 by welding. These negative electrode intermediate leads 55 are joined and bundled together by welding. A negative electrode main lead 56 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more is connected to a negative electrode intermediate lead 55 having one end bundled by resistance welding, and the other end is exposed to the lower surface of the lid 43 It is connected to the lower end surface of 46 by welding. The plurality of negative electrode intermediate leads 55 and the negative electrode main lead 56 constitute a negative electrode lead.

  In addition, laser welding, resistance welding, ultrasonic welding, etc. are mentioned for the welding used for the connection of a lead extraction part and intermediate | middle lead in 3rd Embodiment, and a connection of an intermediate | middle lead and a main lead, etc., for example.

  The details of each member of the nonaqueous electrolyte battery are the same as those described in the first embodiment.

  A positive electrode including a current collector having a spiral lead extraction portion having a contact angle with respect to 20 ° C. water of 45 ° or less and a strip-shaped current collector body having a contact angle with respect to water of 20 ° C. exceeding 45 °, For example, it can be produced by the following method.

  First, a positive electrode active material, a binder and a conductive agent are suspended in an appropriate solvent to prepare a coating slurry. This coating slurry is applied to one or both sides of a current collector body, that is, a current collector excluding a lead extraction portion, of a current collector made of an aluminum foil having a purity of 99% or more or an aluminum alloy foil having a purity of 99% or more. And drying to form a positive electrode layer. Subsequently, after the current collector on which the positive electrode layer is formed is placed in, for example, a holder in the chamber of the atmospheric pressure plasma apparatus, plasma is generated in the chamber in the atmospheric pressure atmosphere by supplying high-frequency power. At this time, the exposed lead extraction portion of the current collector is exposed to plasma, and the rolling oil on the surface is removed.

  In the positive electrode obtained by such a method, the lead-out portion protruding in a spiral shape of the current collector has a property that the contact angle with water at 20 ° C. is 45 ° or less by removing the rolling oil, and the current collector of the current collector The main body shows the property that the contact angle with water at 20 ° C. exceeds 45 ° while the rolling oil remains.

  Further, a negative electrode including a current collector having a lead extraction portion protruding in a spiral shape with a contact angle with respect to 20 ° C. water of 45 ° or less and a current collector body with a contact angle with respect to 20 ° C. water exceeding 45 °, For example, it can be produced by the following method.

  First, a negative electrode active material, a binder and, if necessary, a conductive agent are suspended in a suitable solvent to prepare a coating slurry. One side or both sides of the current collector, excluding the lead-out portion protruding in a spiral shape, from the coated slurry of the aluminum foil having a purity of 99% or more or the aluminum alloy foil having a purity of 99% or more. And dried to form a negative electrode layer. Subsequently, after the current collector on which the negative electrode layer is formed is placed in, for example, a holder in the chamber of the atmospheric pressure plasma apparatus, plasma is generated in the atmospheric pressure chamber by supplying high-frequency power. At this time, the exposed lead extraction portion of the current collector is exposed to plasma, and the rolling oil on the surface is removed.

  In the negative electrode obtained by such a method, the lead-out portion protruding in a spiral shape of the current collector has a property that the contact angle with water at 20 ° C. is 45 ° or less by removing the rolling oil, and the current collector of the current collector The main body shows the property that the contact angle with water at 20 ° C. exceeds 45 ° while the rolling oil remains.

  As described above, according to the third embodiment, the current collector 51 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more of the positive electrode 49 incorporated in the flat spiral electrode group 48 shown in FIGS. By making the lead extraction part 51b protruding in a shape of a contact angle with water at 20 ° C. 45 ° or less, that is, a property showing high wettability, a plurality of lead extraction parts 51b protruding in a spiral shape of the positive electrode 49 are formed. When welding the positive intermediate lead 53, high connection reliability can be achieved.

  Similarly, in the current collector 52 made of aluminum having a purity of 99% or more or aluminum alloy having a purity of 99% or more of the negative electrode 50 incorporated in the flat spiral electrode group 48, the lead-out portion 52b protruding in a spiral shape is placed at 20 ° C. with water. High contact reliability is achieved when the negative electrode intermediate lead 55 is welded to the lead-out portion 52b protruding in a spiral shape of the negative electrode 50 by making the contact angle with respect to the electrode 45 ° or less, that is, exhibiting high wettability. it can.

  Therefore, in the multipoint connection structure in which the plurality of positive intermediate leads 53 and the plurality of negative intermediate leads 55 are connected to the lead extraction portions 51b and 52b protruding in a spiral shape of the current collectors 51 and 52 in the positive electrode 49 and the negative electrode 50, respectively. The lead extraction portions 51b and 52b protruding in a spiral shape of the current collectors 51 and 52 have a contact angle with respect to water at 20 ° C. of 45 ° or less, so that the lead extraction portions 51b and 52b protruding in a spiral shape and a plurality Since the high connection reliability between the intermediate leads 53 and 55 can be ensured, it is possible to provide a non-aqueous electrolytic battery with excellent large current characteristics.

  Further, the current collector main body 51a on which the positive electrode layer is formed and the current collector main body 52b on which the negative electrode layer is formed are described in the first embodiment by making the contact angle with water at 20 ° C. exceed 45 °. In the same manner as described above, the flow of coating slurry to the lead extraction portions 51b and 52b of the positive electrode 49 and the negative electrode 50 in the step of applying the coating slurry is suppressed or prevented, and the coating agent falls off. Since the resulting short circuit or increase in resistance of the lead extraction portion can be prevented, it can greatly contribute to the improvement of the yield of the nonaqueous electrolyte battery.

In particular, in the negative electrode 50 having a negative electrode layer containing a negative electrode active material having a lithium occlusion potential of 0.4 V vs Li / Li ⁺ or higher, the current collector 52 made of aluminum having a purity of 99% or higher or an aluminum alloy having a purity of 99% or higher is used. As described in the first embodiment, the lead extraction part 52b is exposed to a plasma atmosphere or the like, the residual rolling oil on the surface is removed, and the contact angle with respect to 20 ° C. water is 45 ° or less. Similarly, a nonaqueous electrolyte battery with reduced self-discharge can be obtained.

(Fourth embodiment)
FIG. 11 is a cross-sectional view showing a nonaqueous electrolyte battery according to the fourth embodiment. Note that. In FIG. 11, the same members as those in FIGS. 8 to 10 used in the description of the third embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the nonaqueous electrolyte battery according to the fourth embodiment, a bottomed rectangular cylindrical insulating member 57 is provided on the inner surface of the metal can 42 of the exterior material 41 as shown in FIG. The insulating member is made of a synthetic resin such as polytetrafluoroethylene (PTFE), and is formed on the inner surface of the metal can 42 by, for example, coating. The flat spiral electrode group 48 having the same configuration and structure as in the third embodiment is housed horizontally in the metal can 42 of the exterior member 41. That is, the metal can 42 has a horizontally long shape, and the flat spiral electrode group 48 is stored horizontally in the metal can 42 so that two opposing spiral surfaces are located on the side of the metal can 42. ing.

  A plurality of positive electrode intermediate leads 53 and a plurality of negative electrode intermediate leads 55 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more and a plurality of negative electrode intermediate leads 55 of the same material are formed in a spiral shape on one side (for example, the left side) of the flat spiral electrode group 48. The lead extraction portion 51b protruding in a spiral shape of the positive electrode on the surface and the lead extraction portion 52b protruding in a spiral shape of the negative electrode on the other (for example, the right side) spiral surface on the lid 43 side (upper side) of the flat spiral electrode group 48 ) Are connected by welding so as to be aligned in the axial direction. The intermediate leads 53 and 55 of the positive electrode and the negative electrode are bundled together by welding.

  A positive electrode main lead 54 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more is connected to a positive intermediate lead 53 having one end bundled by resistance welding from the side thereof, and the other end is directly below the positive terminal 45. Is connected to the lower surface of the lid 43 by welding. The negative electrode main lead 56 made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more is connected to the negative electrode intermediate lead 55 having one end bundled by resistance welding from the side thereof, and the other end is the bottom surface of the lid 43 It is connected to the lower end surface of the negative electrode terminal 46 exposed by welding.

  In addition, laser welding, resistance welding, ultrasonic welding, etc. are mentioned as welding used for the connection of the lead extraction part and intermediate | middle lead in 4th Embodiment, the connection of an intermediate | middle lead, and a main lead, etc., for example.

As described above, according to the fourth embodiment, it is possible to provide a non-aqueous electrolytic battery excellent in large current characteristics as in the third embodiment described above, and can greatly contribute to the improvement of the yield of the non-aqueous electrolyte battery. In addition, self-discharge can be reduced in a nonaqueous electrolyte battery including a negative electrode having a negative electrode layer containing a negative electrode active material having a lithium occlusion potential of 0.4 V vs Li / Li ⁺ or higher.

  Further, the flat spiral electrode group 48 is accommodated horizontally in the metal can 42 of the exterior member 41, and the plurality of positive electrode intermediate leads 53 and the plurality of negative electrode intermediate leads 55 are connected to the positive and negative electrodes of the flat spiral electrode group 48. The other end of the main lead 56 of the negative electrode is connected by welding so as to be aligned in the axial direction on the lid 43 side (upper side) of the flat spiral electrode group 48 respectively to the lead extraction portions 51b and 52b protruding in a spiral shape. In addition, since the other end of the positive main lead 54 can be pulled out and connected to the relatively thick lid 43 side, the positive main lead 54 is connected to the bottom of the thin metal can 42 as in the third embodiment. As compared with the case, the assembly becomes easier and the connection reliability can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings described above.

Example 1
<Preparation of positive electrode>
N-methyl-2 containing 89% by weight of LiCoO _{2 as a} positive electrode active material, 3% by weight of graphite powder and 3% by weight of acetylene black as a conductive agent, and 5% by weight of polyvinylidene fluoride (PVdF) as a binder. -Dispersed in a pyrrolidone (NMP) solvent to prepare a positive electrode working slurry. The slurry was applied to an aluminum foil having a thickness of 99% or more with a thickness of 15 μm, dried, and pressed to form a positive electrode layer having a density of 3.3 g / cm ³ to produce a positive electrode material.

<Production of negative electrode>
91% by weight of Li ₄ Ti ₅ O _{12 as} a negative electrode active material, 7% by weight of graphite as a conductive agent, and 2% by weight of PVdF as a binder were mixed in an N-methyl-2-pyrrolidone (NMP) solution. Thus, a negative electrode coating slurry was prepared. This slurry was applied to a current collector made of an aluminum foil having a thickness of 15% or more and having a purity of 99% or more, dried, and pressed to produce a negative electrode material having a negative electrode layer having a density of 2.1 g / cm ³ .

<Preparation of non-aqueous electrolyte>
A nonaqueous electrolyte was prepared by mixing 2M LiBF ₄ in a mixed solvent in which ethylene carbonate (EC): propylene carbonate (PC): γ-butyrolactone (GBL) was mixed at a volume ratio of 1: 1: 4.

<Battery assembly>
The positive electrode material was punched out to produce a positive electrode. As shown in FIG. 2A, the punched piece (positive electrode) has a rectangular current collector body in which an aluminum foil current collector and a strip shape integrally projecting from the current collector body. And a lead extraction part, and a structure in which a positive electrode layer is formed on the current collector body. This positive electrode was placed on a holder in a chamber of an atmospheric pressure plasma apparatus, and plasma was generated in the atmospheric pressure atmosphere chamber by supplying high frequency power to expose the exposed lead extraction portion of the current collector to the plasma. As a result of this treatment, the lead takeout part has a contact angle with water of 20 ° C. of 20 °.

  Similarly, the negative electrode material was punched out to produce a positive electrode. As shown in FIG. 2B, the punched piece (negative electrode) has a rectangular current collector body and a strip shape in which the aluminum foil current collector protrudes integrally from the current collector body. And a lead extraction portion, and a structure in which a negative electrode layer is formed on the current collector body. The negative electrode was placed in a holder in the chamber of the atmospheric pressure plasma apparatus, and plasma was generated in the atmospheric pressure atmosphere chamber by supplying high-frequency power to expose the exposed lead extraction portion of the current collector to the plasma. As a result of this treatment, the lead takeout part has a contact angle with water of 20 ° C. of 20 °.

  Note that the current collector body covered with the positive electrode layer of the positive electrode and the current collector body covered with the negative electrode layer of the negative electrode had a contact angle of 105 ° with water at 20 ° C.

  Next, a rectangular positive electrode and a negative electrode are alternately inserted into a folded portion of a separator made of a cellulose nonwoven fabric folded in a ninety-nine shape and stacked, and the end of the separator covers the outer peripheral side surface of the rectangular columnar laminate. Thus, the rectangular laminated electrode group shown in FIG. Next, after joining and bundling the lead extraction portions of the plurality of positive electrodes and the plurality of negative electrodes of the electrode group by laser welding, respectively, the positive electrode and negative electrode leads made of aluminum are respectively laser-welded to the bundled lead extraction portions. Joined and connected. Next, prepare a lid made of aluminum having the vent hole, positive electrode terminal and negative electrode terminal shown in FIG. 1, and connect the positive lead extending from the electrode group by laser welding to the lower surface of the lid directly below the positive electrode terminal. Then, the negative electrode lead was joined and connected to the lower end surface of the negative electrode terminal exposed on the lower surface of the lid by laser welding. After inserting the electrode group to which the lid was connected into a 0.5 mm thick rectangular aluminum can and injecting electrolyte, the lid was fitted into the opening of the aluminum can and the lid was canned by laser welding. The prismatic non-aqueous electrolyte battery having the structure shown in FIG. 1 and having the battery capacity of 1 Ah was assembled.

(Example 2)
The positive electrode material of Example 1 was punched out to produce a positive electrode. As shown in FIG. 5A, the punched piece (positive electrode) includes a strip-shaped current collector body having an aluminum foil current collector and a plurality of strips integrally projecting from the current collector body. And has a structure in which a positive electrode layer is formed on a band-shaped current collector body. The positive electrode was placed in a holder in a chamber of an atmospheric pressure plasma apparatus, and plasma was generated in the atmospheric pressure chamber by supplying high-frequency power to expose a plurality of lead extraction portions exposed to the current collector to the plasma. The plurality of lead take-out portions have the property that the contact angle with respect to 20 ° C. water is 20 ° by this treatment.

  Similarly, the negative electrode material of Example 1 was punched out to produce a negative electrode. As shown in FIG. 5B, the punched piece (negative electrode) includes a strip-shaped current collector main body and a plurality of strips integrally protruding from the current collector main body. And a negative electrode layer formed on the band-shaped current collector body. This negative electrode was placed in a holder in a chamber of an atmospheric pressure plasma apparatus, and plasma was generated in the atmospheric pressure chamber by supplying high-frequency power to expose a plurality of lead extraction portions exposed to the current collector to the plasma. The plurality of lead take-out portions have the property that the contact angle with respect to 20 ° C. water is 20 ° by this treatment.

  Note that the current collector body covered with the positive electrode layer and the current collector body covered with the negative electrode layer had a contact angle with water of 20 ° C. of 105 °.

  Further, the positions (intervals) of the plurality of lead extraction portions of the positive electrode and the negative electrode are flat spiral electrodes obtained by spirally winding together with the separator and press-molding according to the second embodiment and FIGS. It was set so that a plurality of lead extraction portions of the positive electrode and the negative electrode were arranged in a direction perpendicular to the straight portion of the group.

  Next, the obtained positive electrode and negative electrode are wound through a band-shaped separator made of a cellulose nonwoven fabric, press-molded, and a plurality of lead extraction portions of the positive electrode and the negative electrode are perpendicular to the straight portion as shown in FIG. A flat spiral electrode group arranged in each direction was prepared. Next, after joining and bundling multiple lead extraction parts of the positive electrode and negative electrode of the electrode group by laser welding, respectively, the positive electrode and negative electrode lead made of aluminum are joined to each bundled lead extraction part by laser welding. Connected. Subsequently, a lid made of aluminum having the vent hole, the positive terminal and the negative terminal shown in FIG. 4 is prepared, and the positive lead extending from the electrode group is joined by laser welding to the lower surface of the lid directly below the positive terminal. Then, the negative electrode lead was joined and connected to the lower end surface of the negative electrode terminal exposed on the lower surface of the lid by laser welding. The electrode group to which the lid was connected was inserted into a rectangular aluminum can having a thickness of 0.5 mm, and an electrolyte solution similar to that in Example 1 was injected, and then the lid was fitted into the opening of the aluminum can. The prismatic nonaqueous electrolyte battery having the structure shown in FIG. 4 and having the battery capacity of 1 Ah was assembled by joining the lid to the can by welding and sealing hermetically.

(Example 3)
The positive electrode material of Example 1 was punched out to produce a positive electrode. As shown in FIG. 9B, the punched piece (positive electrode) is integrally formed with a current collector body made of a strip of aluminum foil and a side surface along the longitudinal direction of the current collector body. And a strip-shaped lead extraction portion formed, and a structure in which a positive electrode layer is formed on the strip-shaped current collector main body. This positive electrode was placed in a holder in a chamber of an atmospheric pressure plasma apparatus, and plasma was generated in the atmospheric pressure atmosphere chamber by supplying high-frequency power to expose the strip-shaped lead extraction portion where the current collector was exposed to the plasma. The strip-shaped lead-out portion became a property having a contact angle of 20 ° with respect to water at 20 ° C. by this treatment.

  Similarly, the negative electrode material of Example 1 was punched out to produce a positive electrode. As shown in FIG. 9A, the punched piece (negative electrode) is formed integrally with a current collector body made of aluminum foil on a strip-shaped current collector body and a side surface along the longitudinal direction of the current collector body. And has a structure in which a negative electrode layer is formed on the band-shaped current collector main body. This negative electrode was placed in a holder in a chamber of an atmospheric pressure plasma apparatus, and plasma was generated in the chamber in an atmospheric pressure atmosphere by supplying high-frequency power to expose the strip-shaped lead extraction portion where the current collector was exposed to the plasma. The strip-shaped lead-out portion became a property having a contact angle of 20 ° with respect to water at 20 ° C. by this treatment.

  Note that the current collector body covered with the positive electrode layer and the current collector body covered with the negative electrode layer had a contact angle with water of 20 ° C. of 105 °.

  Subsequently, it wound around through the strip-shaped separator which consists of a cellulose nonwoven fabric between the obtained positive electrode and negative electrode, and was press-molded, and the flat spiral electrode group was produced. As shown in FIG. 10 described above, the lead lead-out portion of the negative electrode protrudes spirally from the spiral surface on the upper side of the electrode group. As shown in FIG. 10, the lead lead-out portion of the positive electrode protrudes spirally from the spiral surface below the electrode group. Subsequently, as shown in FIG. 10 described above, after a plurality of intermediate leads made of aluminum are connected by laser welding to a plurality of lead extraction portions protruding in a spiral shape of the positive electrode and the negative electrode of the electrode group, respectively, the positive electrode and the negative electrode A plurality of intermediate leads were joined and bundled by laser welding. Main leads made of aluminum were joined and connected to the bundled intermediate leads by laser welding. Subsequently, a lid made of aluminum having the vent hole, the positive electrode terminal and the negative electrode terminal shown in FIG. 8 is prepared, and the main lead of the negative electrode extending from the electrode group is exposed to the lower end surface of the negative electrode terminal exposed on the lower surface of the lid. They were joined and connected by welding. The electrode group to which the lid was connected was inserted into a rectangular aluminum can having a thickness of 0.5 mm, and the main lead extending from the positive electrode of the electrode group was joined and connected to the inner surface of the bottom of the aluminum can by laser welding. After injecting the same electrolytic solution, the lid is fitted into the opening of the aluminum can, and the lid is joined to the can by laser welding and hermetically sealed to thereby have a battery capacity of 1 Ah as shown in FIG. A rectangular non-aqueous electrolyte battery having the structure shown in FIG.

Example 4
A flat spiral electrode group having the same positive and negative intermediate leads as in Example 3 connected to a 0.5 mm-thick square aluminum can in a horizontal manner with its spiral surface facing the inner surface of the can A prismatic nonaqueous electrolyte battery having the structure shown in FIG. 11 and having a battery capacity of 1 Ah was assembled in the same manner as in Example 3.

(Comparative Example 1)
A nonaqueous electrolyte battery similar to that of Example 1 was assembled, except that plasma irradiation was not performed on the strip-shaped lead extraction portion of the positive and negative electrode current collectors. In addition, these lead extraction parts had a contact angle of 105 ° with respect to 20 ° C. water.

(Comparative Example 2)
A nonaqueous electrolyte battery similar to that of Example 2 was assembled, except that plasma irradiation was not performed on the plurality of strip-shaped lead extraction portions of the positive and negative electrode current collectors. In addition, these lead extraction parts had a contact angle of 105 ° with respect to 20 ° C. water.

(Comparative Example 3)
A non-aqueous electrolyte battery similar to that of Example 3 was assembled, except that plasma irradiation was not performed on the strip-shaped lead extraction portion of the positive and negative electrode current collectors. In addition, these lead extraction parts had a contact angle of 105 ° with respect to 20 ° C. water.

(Comparative Example 4)
A non-aqueous electrolyte battery similar to that of Example 4 was assembled, except that plasma irradiation was not performed on the strip-shaped lead extraction portion of the positive and negative electrode current collectors. In addition, these lead extraction parts had a contact angle of 105 ° with respect to 20 ° C. water.

  About the obtained non-aqueous electrolyte battery of Examples 1-4 and Comparative Examples 1-4, battery resistance and a large current discharge characteristic were evaluated with the following method.

<Evaluation of battery resistance>
After the obtained battery was charged to a fully charged state, discharging was performed for 0.5 Ah to obtain a discharge depth of 50%. The open circuit voltage (V1) of a battery having a discharge depth of 50% was measured. When this battery was discharged at a current value of 40 A, the voltage value (V2) after 5 seconds was measured. From these measurement results, the battery resistance at the time of discharging at 40 A for 5 seconds was obtained by the following formula (1).

Battery resistance (Ω) = (V1−V2) / 40 (1)
For example, in Example 1, V1 is 2.368V and V2 is 2.121V, and by substituting these voltage values into the formula (1), the battery resistance is about 0.00618Ω (about 6.18mΩ). Is required.

<Evaluation of large current discharge characteristics>
After charging the battery after measuring the battery resistance to a fully charged state, the discharge capacity (C1) when discharging until the battery voltage reached 2 V with a discharge current of 1 C was measured. Furthermore, after the battery was charged to a fully charged state again, the discharge capacity (C20) when discharging until the battery voltage reached 2 V with a discharge current of 20 C was measured. From these measurement results, the maintenance ratio of the 20 C discharge capacity with respect to the 1 C discharge capacity was obtained by the following equation (2).

Discharge capacity maintenance rate = (C20 / C1) × 100 (2)
For example, in Example 1, C1 is 1003 mAh and C20 is 804 mAh, and by substituting these discharge capacities into the above equation (2), it is required that the discharge capacity retention rate is about 80.16%.

The battery resistance and large current discharge characteristics of the batteries of Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1 below.

  As apparent from Table 1, the batteries of Examples 1 to 4 are superior in battery resistance and large current discharge characteristics as compared with the batteries of Comparative Examples 1 to 4 corresponding to Example 1. .

(Comparative Example 5)
A negative electrode current collector made of aluminum foil was placed in a holder in a chamber of an atmospheric pressure plasma apparatus, and plasma was generated in the chamber in an atmospheric pressure atmosphere by supplying high-frequency power to expose the entire surface of the current collector to the plasma. By this treatment, the current collector was changed to a 20 ° contact angle with water at 20 ° C. Using the obtained negative electrode current collector, a negative electrode material was prepared in the same manner as in Example 1, and the negative electrode having the shape shown in FIG. A rectangular nonaqueous electrolyte battery having the structure shown in FIG. 1 and having the battery capacity of 1 Ah similar to that of Example 1 except that this negative electrode was used was assembled.

  With respect to the 500 nonaqueous electrolyte batteries of Comparative Example 5 and Example 1 obtained above, the yield (number of defective batteries) was examined by the following method.

<Evaluation of yield>
After assembling 500 batteries by the method of Comparative Example 5 and Example 1, these batteries were left in a fully charged state for 30 days in an environment of 25 ° C., and then subjected to additional charging so as to be in a fully charged state again. If the charge capacity at that time was 10% or more of the battery capacity, it was judged that there was a short-circuited portion inside the battery, and a failure was determined.

  As a result, it was confirmed that in Example 1, the number of defective batteries was 1 out of 500, whereas in Comparative Example 5, the number of defective batteries was 6 out of 500, and the yield was low.

1 is a cross-sectional view showing a nonaqueous electrolyte battery according to a first embodiment of the present invention. The front view which shows the positive electrode and negative electrode which are integrated in the nonaqueous electrolyte battery of FIG. The perspective view of the electrode group integrated in the nonaqueous electrolyte battery of FIG. Sectional drawing which shows the nonaqueous electrolyte battery which concerns on 2nd Embodiment of this invention. FIG. 5 is a development view of a positive electrode and a negative electrode incorporated in the nonaqueous electrolyte battery of FIG. 4. The top view of the electrode group integrated in the nonaqueous electrolyte battery of FIG. The figure explaining the positional relationship of the some lead extraction part of the expand | deployed negative electrode for arranging the lead extraction part of a negative electrode along with the linear part of an electrode group. Sectional drawing which shows the nonaqueous electrolyte battery which concerns on 3rd Embodiment of this invention. FIG. 9 is a development view of a negative electrode and a positive electrode incorporated in the nonaqueous electrolyte battery of FIG. 8. The perspective view of the flat spiral electrode group integrated in the nonaqueous electrolyte battery of FIG. Sectional drawing which shows the nonaqueous electrolyte battery which concerns on 4th Embodiment of this invention. The figure for demonstrating the contact angle with respect to 20 degreeC water.

Explanation of symbols

  1, 2, 41 ... exterior material, 2, 22, 42 ... metal can (aluminum can), 3, 23, 43 ... lid, 6, 26, 46 ... negative electrode terminal, 8, 28, 48 ... electrode group, 9 , 29, 49 ... positive electrode, 10, 30, 50 ... negative electrode, 11, 31 ... separator, 12, 32, 51 ... positive electrode current collector, 12a, 32a, 51a ... current collector body, 12b, 32b, 51b ... Lead extraction part, 13, 33, 52 ... negative electrode current collector, 13a, 33a, 52a ... current collector body, 13b, 33b, 52b ... lead extraction part, 14, 34 ... positive electrode lead, 15, 35 ... negative electrode lead 53 ... Positive electrode intermediate lead, 54 ... Positive electrode main lead, 55 ... Negative electrode intermediate lead, 56 ... Negative electrode main lead.

Claims (4)

Exterior material;
An electrode group having a structure in which a plurality of positive electrodes, a plurality of negative electrodes, and separators interposed between the positive electrodes and the negative electrodes are stacked in the exterior material;
A positive electrode lead connected to the plurality of positive electrodes;
A negative electrode lead connected to the plurality of negative electrodes;
Comprising a non-aqueous electrolyte housed in the exterior material,
Each of the positive electrodes is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a current collector body and a current collector having a lead extraction portion integrally projecting from the body, and the current collector body A positive electrode layer containing a positive electrode active material formed on one side or both sides of each, and each lead extraction part is bonded and bundled together by welding,
The lead extraction part of each positive electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. exceeding 45 °,
The positive electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and connected to the lead-out portions of the bundled positive electrodes by welding,
Each negative electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a current collector body and a current collector having a lead-out portion protruding integrally from the body, and the current collector body A negative electrode layer containing a negative electrode active material formed on one side or both sides of each, and each lead extraction part is joined and bundled together by welding,
The lead extraction part of each negative electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. of more than 45 °, and the negative electrode lead has a purity of 99% or more A non-aqueous electrolyte battery comprising: an aluminum alloy having a purity of 99% or more and connected to the lead-out portions of the bundled negative electrodes by welding. Exterior material;
An electrode group having a structure in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound in a spiral shape, housed in the exterior material;
A positive electrode lead connected to the positive electrode;
A negative electrode lead connected to the negative electrode;
Comprising a non-aqueous electrolyte housed in the exterior material,
The positive electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a strip-shaped current collector body and a current collector having a plurality of lead extraction portions integrally projecting from the current collector body; A positive electrode layer containing a positive electrode active material formed on one side or both sides of the belt-like current collector body, and each lead extraction part is joined and bundled together by welding,
Each lead extraction part of the positive electrode has a contact angle with respect to water at 20 ° C. of 45 ° or less, and the current collector body has a contact angle with respect to water at 20 ° C. exceeding 45 °,
The positive electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and connected by welding to a plurality of lead extraction portions bundled with the positive electrode,
The negative electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and has a strip-shaped current collector body and a current collector having a plurality of lead extraction portions integrally projecting from the current collector body; A negative electrode layer containing a negative electrode active material formed on one side or both sides of the strip-shaped current collector body, and each lead extraction part is joined and bundled together by welding,
Each lead take-out part of the negative electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. of more than 45 °, and the negative electrode lead has a purity of 99% or more A non-aqueous electrolyte battery comprising: an aluminum alloy having a purity of 99% or more and connected to a plurality of lead-out portions bundled with the negative electrode by welding. Exterior material;
An electrode group having a structure in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound in a spiral shape, housed in the exterior material;
A positive electrode lead connected to the positive electrode;
A negative electrode lead connected to the negative electrode;
Comprising a non-aqueous electrolyte housed in the exterior material,
The positive electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and takes out a strip-shaped current collector body and a strip-shaped lead integrally formed on a side surface along the longitudinal direction of the current collector body. And a positive electrode layer containing a positive electrode active material formed on one side or both sides of the band-shaped current collector body, and the lead take-out part spirals on one spiral surface of the electrode group. Protruding into a shape,
The lead lead-out part of the positive electrode has a contact angle with respect to 20 ° C. water of 45 ° or less, and the current collector body has a contact angle with respect to water of 20 ° C. exceeding 45 °,
The positive electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and is connected to a plurality of lead-out portions protruding in a spiral shape of the positive electrode by welding, and is joined and bundled by welding. A plurality of intermediate leads, and a main lead made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more and connected to the bundled intermediate leads by welding,
The negative electrode is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and is formed on a side surface opposite to the lead-out portion of the positive electrode along the longitudinal direction of the strip-shaped current collector body and the current collector body. A current collector having an integrally formed strip-shaped lead extraction portion; and a negative electrode layer containing a negative electrode active material formed on one or both surfaces of the strip-shaped current collector body, wherein the lead extraction portion is Projecting spirally on the other spiral surface of the electrode group,
The lead extraction part of the negative electrode has a contact angle with water of 20 ° C. of 45 ° or less, the current collector body has a contact angle with water of 20 ° C. exceeding 45 °,
The negative electrode lead is made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more, and is connected by welding to a plurality of lead extraction portions protruding in a spiral shape of the negative electrode, and is joined and bundled by welding. A non-aqueous electrolyte battery comprising a plurality of intermediate leads and a main lead made of aluminum having a purity of 99% or more or an aluminum alloy having a purity of 99% or more and connected to the bundled intermediate leads by welding. .   4. The nonaqueous electrolyte battery according to claim 1, wherein the current collectors of the positive electrode and the negative electrode are JIS H 0001 aluminum foil. 5.

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