JP2017054706A - Electrode, method for manufacturing electrode, and nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode capable of suppressing self discharge of a battery irrespective of thickness of an insulating layer, a method for manufacturing the same, and a nonaqueous electrolyte battery with suppressed self discharge.SOLUTION: There is provided an electrode 1 including a collector 2 having an outer edge 2c, active material containing layers 4a and 4b, first insulating layers 5a and 5b, a second insulating layer 6, and a coupling part 7. The active material containing layers 4a and 4b are formed in at least a part of a surface with the exception of the outer edge of the collector. The active material containing layers 4a and 4b also include a first surface 4c and a second surface 4d. The first insulating layers 5a and 5b cover the first surface 4c and second surface 4d of the active material containing layers 4a and 4b. The first insulating layers 5a and 5b also include a particulate insulator. The second insulating layer 6 covers a surface of the outer edge 2c of the collector 2. The second insulating layer 6 also includes a fibrous insulator. The first insulating layers 5a and 5b, and the second insulating layer 6 are in contact with the coupling part 7.SELECTED DRAWING: Figure 5

Description

  Embodiments described herein relate generally to an electrode, an electrode manufacturing method, and a nonaqueous electrolyte battery.

  In secondary batteries such as lithium secondary batteries, a porous separator is used in order to avoid contact between the positive electrode and the negative electrode. Usually, the separator is prepared as a free-standing film separate from the positive electrode and the negative electrode. A separator is disposed between the positive electrode and the negative electrode to form a unit structure (electrode cell), which is wound or laminated to form a battery.

  A general separator includes a microporous membrane made of a polyolefin resin film. Such a separator is produced, for example, by extruding a melt containing a polyolefin resin composition into a sheet, extracting and removing substances other than the polyolefin resin, and then stretching the sheet.

  Since the separator made of a resin film needs to have mechanical strength so as not to be broken at the time of producing a battery, it is difficult to make it thinner to some extent. Therefore, especially in a battery of a type in which a large number of battery cells are stacked or wound, the thickness of the separator limits the amount of unit battery layer that can be stored per unit volume of the battery. This leads to a decrease in battery capacity.

JP2014-41817

  The problem to be solved by the present invention is to provide an electrode capable of suppressing the self-discharge of the battery regardless of the thickness of the insulating layer, a manufacturing method thereof, and a nonaqueous electrolyte battery in which the self-discharge is suppressed. There is.

  According to the first embodiment, an electrode including a current collector having an outer edge portion, an active material-containing layer, a first insulating layer, a second insulating layer, and a connecting portion is provided. The active material-containing layer is formed on at least a part of the surface excluding the outer edge of the current collector. The active material-containing layer has a first surface and a second surface. The first insulating layer covers the first surface and the second surface of the active material-containing layer. The first insulating layer includes a particulate insulator. The second insulating layer covers the surface of the outer edge portion of the current collector. The second insulating layer includes a fibrous insulator. In the coupling portion, the first insulating layer and the second insulating layer are in contact with each other.

  In addition, according to the first embodiment, the step of preparing the insulating layer non-formed electrode (first step), the step of obtaining the first insulating layer (second step), the second insulating layer An electrode manufacturing method including a obtaining step (third step) is provided. In the first step, a current collector having an outer edge, and an active material-containing layer formed on at least a part of the surface excluding the outer edge of the current collector and having a first surface and a second surface An insulating layer-unformed electrode is prepared. In the second step, the first insulating layer is obtained by applying and drying a slurry containing a particulate insulator and a binder on the first surface and the second surface of the active material-containing layer. In the third step, the second insulating layer is obtained by directly forming a fibrous insulator on the surface of the outer edge portion of the current collector at the same time as or different from the step of obtaining the first insulating layer.

  According to 2nd Embodiment, the nonaqueous electrolyte battery containing the positive electrode, the negative electrode which consists of an electrode of 1st Embodiment, and a nonaqueous electrolyte is provided.

The perspective view which shows the 1st example of the electrode which concerns on 1st Embodiment. The perspective view which shows the 2nd example of the electrode which concerns on 1st Embodiment. The perspective view which shows the 3rd example of the electrode which concerns on 1st Embodiment. The perspective view which shows the 4th example of the electrode which concerns on 1st Embodiment. Sectional drawing obtained when the electrode shown in FIG. 1 is cut | disconnected along a tab extension direction. Sectional drawing obtained when the electrode shown in FIG. 4 is cut | disconnected along a long side direction. Sectional drawing obtained when cut | disconnecting the electrode in which an insulating layer is not formed along the tab extension direction. The partial notch perspective view of the 1st example of the nonaqueous electrolyte battery which concerns on 2nd Embodiment. Sectional drawing which cut | disconnected the electrode group along the tab extension direction. The perspective view which shows the structure of the other example of an electrode group. The disassembled perspective view of the 2nd example of the nonaqueous electrolyte battery which concerns on 2nd Embodiment. The perspective view which shows the electrode group used for the 3rd example of the nonaqueous electrolyte battery which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
According to the first embodiment, a current collector having an outer edge portion and an active material containing the first surface and the second surface formed on at least a part of the surface excluding the outer edge portion of the current collector An electrode is provided that includes a layer, a first insulating layer, a second insulating layer, and a coupling portion. The first insulating layer covers the first surface and the second surface of the active material-containing layer, and includes a particulate insulator. The second insulating layer covers the surface of the outer edge portion of the current collector and includes a fibrous insulator. In the connecting portion, the first insulating layer and the second insulating layer are in contact with each other. The contact between the first insulating layer and the second insulating layer can be confirmed with an optical microscope. In the connecting portion, it is desirable that the first insulating layer and the second insulating layer are integrated.

  Here, the 1st surface and 2nd surface of an active material content layer are the main surfaces of an active material content layer, and are the surfaces which have the largest area in an active material content layer.

  Since the first insulating layer can have a lower porosity than the second insulating layer, the first insulating layer can be a thin and dense insulating layer. On the other hand, since the first insulating layer is adhered to the active material-containing layer surface and the current collector surface with a binder or the like, the first insulating layer is easily peeled off from the electrode when the binder deteriorates. Further, the first insulating layer is inferior in adhesion to the current collector as compared with the second insulating layer.

  As in the embodiment, the first surface and the second surface of the active material-containing layer are covered with the first insulating layer, and the surface of the outer edge portion of the current collector is covered with the second insulating layer. By providing a connecting portion where the insulating layer and the second insulating layer are in contact with each other, the adhesion between the current collector and the insulating layer is improved, and the contact area between the electrode including the second insulating layer and the first insulating layer is increased. Therefore, peeling and dropping of the first insulating layer from the electrode can be suppressed. As a result, it is possible to suppress a minute short circuit between the electrode and the counter electrode facing each other through the first insulating layer, so that self-discharge of the battery can be suppressed. In addition, the second insulating layer can suppress the occurrence of an internal short circuit when the outer edge portion of the current collector is in contact with the counter electrode in a battery manufacturing process (particularly, an electrode group manufacturing process) or the like.

  Since the effect of suppressing the peeling and dropping of the first insulating layer can be obtained even if the thickness of the first insulating layer is reduced, the volume occupied by the first insulating layer in the electrode group is reduced to reduce the volume energy density. It is possible to improve.

  Since the outer edge surface of the current collector covered with the second insulating layer has a small contribution to the electrode reaction, the consumption rate of the electrolytic solution is slower than that of the first insulating layer. Therefore, the electrolytic solution held in the second insulating layer can be supplied to the first insulating layer through the connecting portion, and the second insulating layer can function as a reservoir for the electrolytic solution. As a result, even when the first insulating layer is thinned, it is possible to avoid the electrolyte of the first insulating layer being depleted. Thereby, battery performance, such as rate performance and lifetime performance, can be improved.

  As described above, by using the separator in which the first insulating layer and the second insulating layer are integrated by the connecting portion, the self-discharge and internal short circuit of the battery can be suppressed, and the volume energy density can be suppressed. Battery performance such as rate performance and life performance can be improved.

  The connecting portion is preferably located on the surface in the vicinity of the outer edge portion of the active material-containing layer. Since the outer edge portion of the active material-containing layer has a smaller area than the first surface and the second surface, the contact area with the first insulating layer is small. Since the connection portion suppresses peeling and dropping of the first insulating layer covering the surface in the vicinity of the outer edge portion of the active material-containing layer, it is possible to reduce the occurrence rate of self-discharge.

  It is desirable that a second insulating layer is formed on the first insulating layer covering one end portion of the first surface and the second surface of the active material-containing layer to form a connection portion. Such a connecting portion can suppress the occurrence of cracks in the first insulating layer when the electrodes are wound for electrode group production, and thus suppress the peeling and dropping of the first insulating layer. Can do.

  A first example to a fourth example of the electrode of the first embodiment are shown in FIGS.

  1 includes a quadrilateral current collector 2, a current collecting tab 3, active material-containing layers 4a and 4b, first insulating layers 5a and 5b, and a second insulating material. Layer 6 is included. FIG. 7 shows an electrode without an insulating layer. As shown in FIG. 7, the current collector 2 has a first surface 2a and a second surface 2b located on the opposite side of the first surface 2a. Here, the first surface and the second surface of the current collector are the main surfaces of the current collector, and are surfaces having the largest area in the current collector. The active material-containing layer 4 a is formed on the first surface 2 a of the current collector 2, and the active material-containing layer 4 b is formed on the second surface 2 b of the current collector 2. The active material-containing layer 4a has a first surface 4c, and the active material-containing layer 4b has a second surface 4d. The outer edge portions of the active material containing layers 4a and 4b are indicated by 4e. The current collector 2 has a protrusion near the center of one side of the outer edge 2c. The projecting portion does not hold the active material-containing layer, and functions as the current collecting tab 3.

  As shown in FIG. 5, the first insulating layer 5a covers at least the first surface 4c of the active material-containing layer 4a. The first insulating layer 5b covers at least the second surface 4d of the active material-containing layer 4b. The first insulating layers 5a and 5b may cover the surfaces (side surfaces) of the outer edge portions 4e of the active material-containing layers 4a and 4b, respectively. The second insulating layer 6 covers at least the surface (side surface) of the outer edge 2 c of the current collector 2. In the case of FIG. 5, the second insulating layer 6 covers the surface of the outer edge portion 4 e of the active material containing layers 4 a and 4 b and the surface of the outer edge portion 2 c of the current collector 2. In the vicinity of the surface of the outer edge portion 4e of the active material containing layers 4a and 4b, the first insulating layers 5a and 5b and the second insulating layer 6 are in contact with each other, and the connecting portion 7 is present. A portion of the surface of the current collecting tab 3 that intersects the surface of the outer edge portion 4 e of the active material containing layers 4 a and 4 b is covered with the second insulating layer 8.

  By the presence of the connecting portion 7 on the surface of the outer edge portion 4e of the active material containing layers 4a and 4b, peeling and dropping off of the first insulating layers 5a and 5b near the outer edge portion of the electrode 1 can be suppressed. Thereby, the self discharge resulting from a leak current can be suppressed. Further, since the contact area between the second insulating layer and the electrode can be increased by forming the second insulating layer 8 on the surface of the current collecting tab 3, the second insulating layer is peeled off and dropped off. Can be suppressed. Therefore, an internal short circuit in which the outer edge portion of the current collector is in contact with the counter electrode can be reduced.

  The electrode 1 of the second example shown in FIG. 2 has the same configuration as that of the first example, except that a plurality of current collecting tabs 3 protrude from one long side of the current collector 2. The same members as those in the first example are denoted by the same reference numerals and description thereof is omitted. As shown in the second example, the electrode 1 can have a plurality of current collecting tabs 3.

  The electrode 1 of the third example shown in FIG. 3 includes a quadrilateral current collector 2, a current collecting tab 3, active material containing layers 4a and 4b, first insulating layers 5a and 5b, Insulating layer 6 is included. The current collector 2 has a protruding portion on one long side of the outer edge portion 2c. The projecting portion does not hold the active material-containing layer, and functions as the current collecting tab 3. The first insulating layer 5a covers at least the first surface 4c of the active material-containing layer 4a. The first insulating layer 5b covers at least the second surface 4d of the active material-containing layer 4b. The first insulating layers 5a and 5b may cover the surfaces (four side surfaces) of the outer edge portion 4e of the active material-containing layers 4a and 4b, respectively. The second insulating layer 6 covers at least the surface (side surface) of the outer edge 2 c of the current collector 2. In the case of FIG. 3, the second insulating layer 6 also covers the surfaces (four side surfaces) of the outer edge portion 4e of the active material-containing layers 4a and 4b. Therefore, on the surface (four side surfaces) of the outer edge portion 4e of the active material-containing layers 4a and 4b, there is a connecting portion 7 where the first insulating layers 5a and 5b and the second insulating layer 6 are in contact. A portion of the surface of the current collecting tab 3 that intersects the surface of the outer edge portion 4e of the active material containing layers 4a and 4b is covered with the second insulating layer 8.

  By the presence of the connecting portion 7 on the surface of the outer edge portion 4e of the active material containing layers 4a and 4b, peeling and dropping off of the first insulating layers 5a and 5b near the outer edge portion of the electrode 1 can be suppressed. Thereby, the self discharge resulting from a leak current can be suppressed. Further, since the contact area between the second insulating layer and the electrode can be increased by forming the second insulating layer 8 on the surface of the current collecting tab 3, the second insulating layer is peeled off and dropped off. Can be suppressed. Therefore, an internal short circuit in which the outer edge portion of the current collector is in contact with the counter electrode can be reduced.

  The electrode 1 of the fourth example shown in FIGS. 4 and 6 includes an active material containing layer on the first insulating layer 5a covering one end parallel to the short side of the first surface 4c of the active material containing layer 4a. The structure is the same as that of the third example except that the second insulating layer 6b is formed on the first insulating layer 5b covering one end portion parallel to the short side of the second surface 4d of the layer 4b. . A portion where the first insulating layer 5 a and the second insulating layer 6 b are in contact with each other is a connecting portion 7. The same members as those in the third example are denoted by the same reference numerals and description thereof is omitted.

  According to the electrode 1 of the fourth example, when the winding is started from the end portion where the second insulating layer 6b is formed during the production of the electrode group, the radius of curvature of the end portion increases, but the first insulating layer 5a , 5b can be prevented from cracking, and therefore the first insulating layers 5a, 5b can be prevented from peeling off and falling off.

Hereinafter, each member included in the electrode will be described.
(1) Current collector Examples of the current collector include a foil made of a conductive material. Examples of the conductive material include aluminum and an aluminum alloy.

The tab is preferably formed of the same material as the current collector. A portion of the current collector where the active material-containing layer is not formed may be used as a tab, but a tab may be prepared separately from the current collector and connected to the current collector by welding or the like. It is.
(2) Active material-containing layer The active material-containing layer may be formed on both surfaces (first surface and second surface) of the current collector, but can also be formed on only one surface.

  The active material-containing layer may contain a binder and a conductive agent in addition to the active material. The electrode can be used for the positive electrode, the negative electrode, or both the positive and negative electrodes.

When the electrode is used as a negative electrode, as the negative electrode active material, carbon materials such as graphite, tin / silicon alloy materials, and the like can be used, and lithium titanate is preferable. Examples of lithium titanate include Li _{4 + x} Ti ₅ O ₁₂ (0 ≦ x ≦ 3) having a spinel structure and Li _{2 + y} Ti ₃ O ₇ (0 ≦ y ≦ 3) having a ramsteride structure. Can be mentioned. The type of the negative electrode active material can be one type or two or more types.

  The average particle size of the primary particles of the negative electrode active material is preferably in the range of 0.001 to 1 μm. The particle shape may be either granular or fibrous. In the case of a fiber, the fiber diameter is preferably 0.1 μm or less. When lithium titanate having an average particle size of 1 μm or less is used as the negative electrode active material, a negative electrode active material-containing layer having high surface flatness is obtained. Further, when lithium titanate is used, the potential is lower than that of a general lithium secondary battery, so that lithium metal does not precipitate in principle. Since the negative electrode active material containing lithium titanate has a small expansion / contraction associated with the charge / discharge reaction, the crystal structure of the active material can be prevented from collapsing.

  Examples of the negative electrode conductive agent include acetylene black, carbon black, and graphite. Examples of the binder for binding the negative electrode active material and the negative electrode conductive agent include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, and styrene-butadiene rubber.

When the electrode is used as a positive electrode, a general lithium transition metal composite oxide can be used as the positive electrode active material. For _{example, LiCoO 2, LiNi 1-x} Co x O 2 (0 <x <0.3), LiMn x Ni y Co z O 2 (0 <x <0.5,0 <y <0.5,0 ≦ z <0.5), LiMn _2−x M _x O ₄ (M is at least one element selected from the group consisting of Li, Mg, Co, Al and Ni, 0 <x <0.2), LiMPO ₄ (M is at least one element selected from the group consisting of Fe, Co, and Ni).

Examples of the positive electrode conductive agent include carbonaceous materials such as acetylene black, carbon black, and graphite. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and fluorine-based rubber.
(3) First insulating layer The first insulating layer includes a particulate insulator. The first insulating layer has, for example, a structure in which particulate insulators are dispersed in a layered base material, a layered aggregate of particulate insulators, and a structure in which particulate insulators are bonded with a binder. It can be. As the particulate insulator, for example, an oxide, a nitride, or the like can be used. One or more types of particulate insulators can be used.

Examples of the oxide include Li ₂ O, BeO, B ₂ O ₃ , Na ₂ O, MgO, Al ₂ O ₃ , SiO ₂ , P ₂ O ₅ , CaO, Cr ₂ O ₃ , Fe ₂ O ₃ , ZnO. , ZrO ₂ , TiO ₂ , zeolite (M _{2 / n} O.Al ₂ O ₃ .xSiO ₂ .yH ₂ O (wherein M is at least one selected from the group consisting of Na, K, Ca and Ba) Metal atoms, n is a number corresponding to the charge of the metal cation M ^{n +} , x and y are the number of moles of SiO ₂ and H ₂ O, and 2 ≦ x ≦ 10, 2 ≦ y ≦ 10) and the like. Examples of the nitride include BN, AlN, Si ₃ N ₄ and Ba ₃ N ₂ .

Furthermore, silicon carbide (SiC), zircon (ZrSiO ₄ ), carbonates (eg, MgCO ₃ and CaCO ₃ ), sulfates (eg, CaSO ₄ and BaSO ₄ ), and composites thereof (eg, a kind of porcelain) Steatite (MgO · SiO ₂ ), forsterite (2MgO · SiO ₂ ), cordierite (2MgO · 2Al ₂ O ₃ · 5SiO ₂ ) and the like can be used as the particulate insulator.

  Among the particulate insulators, silicon dioxide particles and aluminum oxide particles are preferable. This is because side reactions can be reduced.

  The shape of the particulate insulator is not particularly limited, and may be any shape such as a spherical shape, a scale shape, a polygonal shape, or a fibrous shape.

  It is preferable to use a particulate insulator having high hardness. When excessive pressure is applied to the first insulating layer, the holes in the layer may be deformed and crushed. The particulate insulator can avoid deformation of holes in the first insulating layer. The impregnation property of the electrolyte and the ionic conductivity are not lowered, and the battery durability is prevented from deteriorating.

  The average particle size of the particulate insulator is preferably in the range of 5 nm to 100 μm. This is because if the average particle size is small, the air permeability value of the first insulating layer may increase and the impregnation of the electrolytic solution may decrease, whereas if the average particle size is large, the particulate insulator This is because it becomes easy to drop off from the first insulating layer. A more preferable range of the average particle diameter is 5 nm to 10 μm, and a further preferable range is 5 nm to 1 μm. When the particulate insulator having an average diameter in such a range is contained in less than about 40% of the total volume of the first insulating layer, a desired effect can be obtained.

  By containing the particulate insulator, the strength of the first insulating layer is increased. For example, when the wound type is used, the bendability is improved and the compression resistance is improved, and even when the laminated type is used, damage at the edge portion at the time of punching can be reduced. Thus, the performance can be maintained while maintaining the rigidity of the insulating layer.

In addition to increasing the strength of the first insulating layer, the resistance to heat shrinkage can be increased by containing the particulate insulator. In particular, when α-Al ₂ O ₃ is used as the material for the particulate insulator, the heat resistance of the first insulating layer is further enhanced.

  It is desirable that the thickness of the first insulating layer be in the range of 12 μm or less. Accordingly, the thickness of the separator is reduced, and the number of electrode windings or the number of stacked layers can be increased, so that a high battery capacity can be obtained. The first insulating layer is preferably thin, and a first insulating layer made of a single particle layer can also be used.

The porosity of the first insulating layer is desirably 30% or more and 70% or less. Thereby, since the leakage current can be prevented even when the thickness of the first insulating layer is reduced, the self-discharge suppressing effect of the battery can be enhanced.
(4) Second insulating layer The second insulating layer includes a fibrous insulator. The second insulating layer is formed directly by supplying a raw material of the fibrous insulating material to the surface of the outer edge of the current collector or the surface of the tab. The second insulating layer may be an aggregate of fibrous insulators.

  Examples of the fibrous insulator include organic fibers. The organic material constituting the organic fiber can be selected from the group consisting of polyamideimide, polyamide, polyolefin, polyether, polyimide, polyketone, polysulfone, cellulose, polyvinyl alcohol (PVA), and polyvinylidene fluoride (PVdF). Examples of the polyolefin include polypropylene (PP) and polyethylene (PE). Polyimide and PVdF are generally considered to be materials that are difficult to form into fibers. When the electrospinning method is employed, such a material can be formed into a fibrous layer. One kind or two or more kinds of organic fibers can be used. Preferable are polyimide, polyamideimide, cellulose, PVdF, and PVA, and more preferable are polyimide, polyamideimide, cellulose, and PVdF.

  In particular, since polyimide is insoluble and infusible at 250 to 400 ° C. and does not decompose, a second insulating layer having excellent heat resistance can be obtained.

  The organic fiber preferably has a length of 1 mm or more and a thickness of 1 μm or less. Since the second insulating layer made of such an organic fiber layer has sufficient strength, porosity, air permeability, pore diameter, electrolytic solution resistance, oxidation-reduction resistance, and the like, it functions well as a separator. The thickness of the organic fiber can be measured by electron microscope (SEM) observation, scanning probe microscope (SPM), TEM, STEM, or the like. Further, the length of the organic fiber is obtained based on the length measurement by SEM observation.

  Since it is necessary to ensure ion permeability and electrolyte-containing liquid properties, 30% or more of the total volume of the fibers forming the second insulating layer is preferably organic fibers having a thickness of 1 μm or less. A more preferable range of the thickness is 350 nm or less, and a more preferable range is 50 nm or less. The volume of the organic fiber having a thickness of 1 μm or less (more preferably 350 nm or less, more preferably 50 nm or less) occupies 80% or more of the total volume of the fibers forming the second insulating layer. . Such a state can be confirmed by SEM observation of the second insulating layer. More preferably, the organic fibers having a thickness of 40 nm or less occupy 40% or more of the total volume of the fibers forming the second insulating layer. When the diameter of the organic fiber is small, the influence of hindering the movement of lithium ions is small.

  The second insulating layer has holes, and the average hole diameter of the holes is preferably 5 nm to 10 μm. The porosity is preferably 10 to 90%. With such pores, a separator having excellent lithium ion permeability and good electrolyte impregnation properties can be obtained. The porosity is more preferably 80% or more. The average pore diameter and porosity of the pores can be confirmed by mercury porosimetry, calculation from volume and density, SEM observation, and gas desorption method. A large porosity in the second insulating layer has a small influence on the movement of lithium ions.

  It is desirable that the porosity of the second insulating layer is larger than the porosity of the first insulating layer. Thereby, the nonaqueous electrolyte retention performance of the second insulating layer can be made higher than that of the first insulating layer. As a result, the nonaqueous electrolyte in the second insulating layer can be supplied to the first insulating layer even if the nonaqueous electrolyte in the first insulating layer is consumed due to charge / discharge reaction or the like. Thus, depletion of the nonaqueous electrolyte in the insulating layer can be avoided, and the life performance of the nonaqueous electrolyte battery can be made excellent.

  The thickness of the second insulating layer is desirably in the range of 12 μm or less. Accordingly, since the thickness of the connecting portion where the first insulating layer and the second insulating layer are in contact with each other can be reduced, it is possible to avoid occurrence of winding deviation when the electrode is wound together with the counter electrode. . The lower limit of the thickness is not particularly limited, but can be 1 μm.

  The thickness of the first insulating layer and the thickness of the second insulating layer are preferably the same, or the thickness of the second insulating layer is preferably thinner than the thickness of the first insulating layer. As a result, the difference in thickness between the connecting portion where the first insulating layer and the second insulating layer are in contact with each other and the other portions can be reduced. Can be reduced.

  The second insulating layer is formed by, for example, an electrospinning method. By using the electrospinning method, the second insulating layer made of the organic fiber layer having the above-described conditions can be easily formed on the electrode surface. The electrospinning method, in principle, forms a single continuous fiber, so that a thin film can ensure resistance to breakage due to bending and film cracking. A single organic fiber constituting the layer has a low probability of fraying or partial loss of the organic fiber layer, which is advantageous in terms of suppressing self-discharge.

  In electrospinning, a solution prepared by dissolving an organic material in a solvent is used as a raw material solution. Examples of the organic material can include the same materials as those described for the organic material constituting the organic fiber. The organic material is used by being dissolved in a solvent at a concentration of, for example, about 5 to 60% by mass. The solvent for dissolving the organic material is not particularly limited. Any solvent such as dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N, N′dimethylformamide (DMF), N-methylpyrrolidone (NMP), water, alcohols, etc. A solvent can be used. For organic materials with low solubility, electrospinning is performed while melting the sheet-like organic material with a laser or the like. In addition, mixing of a high boiling point organic solvent and a low melting point solvent is allowed.

  The organic fiber layer is formed by discharging the raw material solution from the spinning nozzle over the surface of a predetermined electrode while applying a voltage to the spinning nozzle using a high-pressure generator. The applied voltage is appropriately determined according to the solvent / solute species, the boiling point / vapor pressure curve of the solvent, the solution concentration, temperature, nozzle shape, sample-nozzle distance, etc. It can be set to 100 kV. The feed rate of the raw material solution is also appropriately determined according to the solution concentration, solution viscosity, temperature, pressure, applied voltage, nozzle shape, and the like. In the case of a syringe type, for example, it can be about 0.1 to 500 μl / min per nozzle. In the case of multiple nozzles or slits, the supply speed may be determined according to the opening area.

  Since the organic fibers are directly formed on the surface of the electrode in a dry state, it is substantially avoided that the solvent of the raw material solution penetrates into the electrode. The residual amount of the solvent inside the electrode is extremely low at a ppm level or less. The residual solvent inside the electrode causes an oxidation-reduction reaction to cause battery loss, leading to deterioration of battery performance. According to the present embodiment, the risk of such inconvenience is reduced as much as possible, so that the performance of the battery can be improved.

  In the organic fiber layer, the porosity can be increased if the organic fiber contained in the organic fiber layer is in a sparse state. For example, it is not difficult to obtain a layer having a porosity of about 90%. It is extremely difficult to form such a layer with a large porosity with particles.

  The second insulating layer made of an organic fiber layer is more advantageous than the inorganic fiber layer in terms of unevenness, ease of cracking, electrolyte-containing properties, adhesion, bending properties, porosity, and ion permeability.

  It is preferable that a cation exchange group is present on the surface of the organic fiber. Since the movement of lithium ions passing through the separator is promoted by the cation exchange group, the performance of the battery is improved. Specifically, rapid charging and rapid discharging can be performed over a long period of time. The cation exchange group is not particularly limited, and examples thereof include a sulfonic acid group and a carboxylic acid group. The fiber having a cation exchange group on the surface can be formed by, for example, an electrospinning method using a sulfonated organic material.

  An electrode is produced by the method demonstrated below, for example.

A slurry containing an active material, a conductive agent and a binder is prepared, and the resulting slurry is applied to both sides of the current collector and dried to form an active material-containing layer. After pressing, if necessary, Cut to desired dimensions. For the current collector tab, do not apply slurry to a part of the current collector and use this part as the current collector tab, or weld a metal plate or the like to the current collector and use the metal plate or the like as the current collector tab. Use. The first insulating layer and the second insulating layer are formed by the following method on the electrode having no insulating layer formed as described above.
(Method for forming first insulating layer)
The slurry in which the particulate insulator and the binder are dispersed in a solvent (for example, water) is applied on the active material-containing layer of the electrode, and then dried to coat the active material-containing layer with the first insulating layer. Examples of the application method include a method using a die coater, gravure coating, spraying by spraying, and the like. Die coaters and gravure coats are excellent in utilization efficiency of raw materials. In addition, spraying is effective in reducing manufacturing costs. Examples of the binder include carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR), and an acrylic binder.
(Method for forming second insulating layer)
For example, an electrospinning method is employed. In the electrospinning method, the electrode on which the second insulating layer is to be formed is grounded to form a ground electrode. The raw material solution is charged by the voltage applied to the spinning nozzle, and the amount of charge per unit volume of the raw material solution increases due to volatilization of the solvent from the raw material solution. Since the volatilization of the solvent and the accompanying increase in the charge amount per unit volume occur continuously, the raw material solution discharged from the spinning nozzle extends in the longitudinal direction and is deposited on the electrode as nano-sized organic fibers. A Coulomb force is generated between the organic fiber and the electrode due to a potential difference between the nozzle and the electrode. Therefore, the contact area with the electrode can be increased by the nano-sized organic fiber, and the organic fiber can be deposited on the electrode, particularly on the current collector and the tab by the Coulomb force. It is possible to increase the peel strength from the. The peel strength can be controlled, for example, by adjusting the solution concentration, the sample-nozzle distance, and the like. Note that in the case where the second insulating layer is not formed on the current collecting tab, the second insulating layer may be formed after masking the current collecting tab.

  The first insulating layer and the second insulating layer can be formed at the same time. However, even if the second insulating layer is formed after the first insulating layer is formed, the second insulating layer is formed. A first insulating layer may be formed later. The portion of the electrode surface covered with the first insulating layer has high insulation, so that organic fibers by electrospinning are hardly deposited, and the current collector and the current collector tab exposed on the electrode surface are not deposited. Organic fibers can be selectively deposited. Therefore, when the second insulating layer is formed after the first insulating layer is formed, the second insulating layer can be selectively formed at a necessary portion.

  In addition, after the electrode group is manufactured using the electrode of the embodiment, the second insulating layer can be deposited on at least a part of the surface of the electrode group.

  The formation speed of the first insulating layer is faster than that of the second insulating layer. Therefore, by covering the first surface and the second surface of the active material-containing layer having a large area ratio in the electrode with the first insulating layer, the formation speed of the insulating layer can be increased, and the electrode is manufactured. Can be shortened.

  The physical properties (porosity, etc.) of the first and second insulating layers contained in the battery can be performed on the first and second insulating layers taken out from the battery by the following method. After the battery is completely discharged or in an inert gas atmosphere such as Ar, the exterior member (for example, a metal container or a laminate film container) is opened, and the electrode structure (electrode group) is taken out. After peeling off the first and second insulating layers from the positive electrode and the negative electrode, the first and second insulating layers are washed with a solvent (for example, diethyl carbonate (DEC), methyl ethyl carbonate (MEC)) to obtain the first Then, the non-aqueous electrolyte adhering to the second insulating layer is removed. Next, the first and second insulating layers are dried and subjected to measurement.

  The thicknesses of the first and second insulating layers are measured after a resin filling process is performed on the electrode structure (electrode group) taken out from the battery exterior member (for example, a metal container or a laminate film container). be able to.

  According to the first embodiment described above, the active material-containing layer is coated, the first insulating layer including the particulate insulator and the surface of the outer edge of the current collector are coated, and the fibrous insulator is coated. There is provided an electrode including a second insulating layer including a connecting portion where the first insulating layer and the second insulating layer are in contact with each other. Since such an electrode can suppress peeling and dropping of the first insulating layer, it can suppress self-discharge of the battery.

In addition, according to the first embodiment, an electrode manufacturing method including a first insulating layer manufacturing step and a second insulating layer manufacturing step is provided. The first insulating layer is obtained by applying a slurry containing a particulate insulator and a binder to the first surface and the second surface of the active material-containing layer and drying it. The second insulating layer is obtained by directly forming a fibrous insulator on the outer edge surface of the current collector at the same time as or different from the step of obtaining the first insulating layer. According to such a method, it is possible to obtain an electrode in which the first insulating layer and the second insulating layer are closely adhered with high strength.
(Second Embodiment)
According to the second embodiment, a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided. The electrode according to the first embodiment can be used for a positive electrode, a negative electrode, or a positive electrode and a negative electrode. The form of the nonaqueous electrolyte battery according to the present embodiment is not particularly limited, and can be, for example, a laminated type, a flat type, a thin type, a square type, a wound type, or a cylindrical type.

  First to third examples of the nonaqueous electrolyte battery are shown in FIGS.

  A non-aqueous electrolyte battery 10 of the first example shown in FIG. 8 is called a thin or flat type, and includes a laminate film exterior member 11, an electrode group 12, a positive electrode terminal 13, a negative electrode terminal 14, and a non-aqueous battery. Contains an electrolyte (not shown). The electrode group 12 has a stacked structure in which positive and negative electrodes are alternately stacked via separators. FIG. 9 shows an example of a laminated structure. The positive electrode 15 includes a positive electrode current collector 15a made of a foil such as aluminum, a positive electrode active material-containing layer 15b, and a positive electrode current collector tab 15c. The positive electrode current collector 15a has a rectangular main body portion and a protruding portion protruding from one side of the main body portion. The positive electrode active material-containing layer 15b is formed on both main surfaces (first surface and second surface) of the main body portion of the positive electrode current collector 15a. A positive electrode active material-containing layer is not formed on the protruding portion, and functions as the positive electrode current collecting tab 15c. The negative electrode 16 has a negative electrode current collector 16a made of a foil such as aluminum, a negative electrode active material-containing layer 16b, and a negative electrode current collector tab 16c. The negative electrode active material-containing layer 16b is formed on both main surfaces of the main body portion of the negative electrode current collector 16a. The negative electrode current collector 16a has a rectangular main body portion and a protruding portion protruding from one side of the main body portion. A negative electrode active material-containing layer is not formed on the protruding portion, and functions as the negative electrode current collecting tab 16c. The separator includes the first insulating layers 5 a and 5 b and the second insulating layer 6. The main surface (first surface) of one negative electrode active material-containing layer 16b is covered with the first insulating layer 5a, and the main surface (second surface) of the other negative electrode active material-containing layer 16b is the first insulating layer. It is covered with a layer 5b. The second insulating layer 6 covers the outer edge surfaces (side surfaces) of the negative electrode current collector 16a and the negative electrode active material-containing layer 16b. The second insulating layer 6 is in contact with the outer edge portions of the first insulating layers 5 a and 5 b, and the place is the connecting portion 7. The positive electrode 15 and the negative electrode 16 are alternately stacked, and the first insulating layer 5a or the first insulating layer 5b is located between the positive electrode active material-containing layer 15b and the negative electrode active material-containing layer 16b. A non-aqueous electrolyte (not shown) is held or impregnated in the electrode group 12. The positive electrode current collecting tab 15 c of each positive electrode 15 is electrically connected to the positive electrode terminal 13, and the negative electrode current collecting tab 16 c of each negative electrode 16 is electrically connected to the negative electrode terminal 14. As shown in FIG. 8, the leading ends of the positive electrode terminal 13 and the negative electrode terminal 14 protrude from the exterior member 1 in a state of being spaced apart from each other.

  According to the multilayer nonaqueous electrolyte battery shown in FIGS. 8 and 9, the first insulating layer is prevented from peeling and dropping near the outer edge portion of the negative electrode, so that self-discharge is suppressed. The battery sealing step is performed by heat sealing after housing the electrode group and the non-aqueous electrolyte in a laminate film exterior member. The heat sealing is performed in a state where the inside of the exterior member is evacuated. Therefore, although pressure is applied in the vicinity of the edge of the electrode group, peeling and dropping off of the first insulating layer are suppressed by the presence of the connecting portion. As a result, it is possible to suppress a minute short circuit between the negative electrode and the positive electrode opposed via the first insulating layer, so that the self-discharge of the battery can be suppressed. Further, the second insulating layer can suppress the occurrence of an internal short circuit when the outer edge of the negative electrode or the negative electrode current collecting tab is in contact with the positive electrode.

  In FIG. 8, the extending direction of the positive electrode terminal and the negative electrode terminal is the same, but the extending direction of the positive electrode terminal and the negative electrode terminal is not limited to the same direction, and as illustrated in the second example of FIG. It is also possible for the extending direction of 13 to be opposite to the extending direction of the negative electrode terminal 14.

  A non-aqueous electrolyte battery 10 of the third example shown in FIG. 11 is called a square shape, and is made of a metal container 20, a wound electrode group 21, a lid 22, a positive electrode terminal 23, a negative electrode terminal 24, A non-aqueous electrolyte (not shown). The wound electrode group 21 has a structure in which a positive electrode 25 and an insulating layer (separator) integrated negative electrode 26 are wound in a flat spiral shape. The electrode 1 having the structure shown in FIG. 3 or 4 is used for the negative electrode 26 integrated with an insulating layer. Therefore, the separator includes the first insulating layer and the second insulating layer. As the positive electrode 25, the electrode 1 having the structure shown in FIG. 3 or FIG. 4 may be used. However, the positive electrode 25 does not include the first insulating layer and the second insulating layer (for example, there is no insulating layer). The same structure as shown in FIG. 3 or FIG. 4 may be used. In the wound electrode group 21, the positive current collecting tab wound in a flat spiral shape is located on one surface, and the negative current collecting tab wound in a flat spiral shape is on the other surface 27. positioned. A first insulating layer is located between the positive electrode active material-containing layer and the negative electrode active material-containing layer. A non-aqueous electrolyte (not shown) is held or impregnated in the electrode group 21. The positive electrode lead 28 is electrically connected to the positive electrode current collecting tab and is also electrically connected to the positive electrode terminal 23. The negative electrode lead 29 is electrically connected to the negative electrode current collecting tab and is also electrically connected to the negative electrode terminal 24. The electrode group 21 is disposed in the container 20 so that the positive electrode lead 28 and the negative electrode lead 29 face the main surface side of the battery container 20. The lid 22 is fixed to the opening of the metal container 20 by welding or the like. The positive electrode terminal 23 and the negative electrode terminal 24 are respectively attached to the lid 22 via an insulating hermetic seal member (not shown).

  According to the wound nonaqueous electrolyte battery shown in FIG. 11, the first insulating layer is prevented from peeling and dropping from the negative electrode located on the inner peripheral side of the electrode group, so that self-discharge is suppressed. . Since the curvature radius of the positive electrode and the negative electrode is larger on the inner peripheral side of the electrode group, cracks are likely to occur in the first insulating layer located on the inner peripheral side, but the first insulating layer is peeled off due to the presence of the connecting portion. And omission are suppressed. As a result, it is possible to suppress a minute short circuit between the negative electrode and the positive electrode opposed via the first insulating layer, so that the self-discharge of the battery can be suppressed. Further, the second insulating layer can suppress the occurrence of an internal short circuit when the outer edge of the negative electrode or the negative electrode current collecting tab is in contact with the positive electrode.

  Further, by using the electrode having the structure shown in FIG. 4 as the negative electrode and starting winding from the end in the short side direction of the negative electrode active material-containing layers 4a and 4b covered with the second insulating layer 6b, the radius of curvature is increased. Although cracks occur in the first insulating layers 5a and 5b on the large inner peripheral side, the second insulating layer 6b is laminated there, so that the first insulating layers 5a and 5b are prevented from peeling and dropping off. can do.

  In order to avoid peeling and dropping of the first insulating layer, it is desirable that the second insulating layer covers at least the main surface of the first insulating layer and the outer edge portion of the active material-containing layer. More preferably, the electrode surface excluding the tip of the current collecting tab is covered with the second insulating layer.

  As shown in FIG. 12, the end surface of the electrode group 21 wound in a spiral shape may be covered with the second insulating layer 30. Thereby, the occurrence of a short circuit at the end face of the electrode group is avoided, and the safety as a battery can be improved.

  The nonaqueous electrolyte used for the nonaqueous electrolyte battery of the embodiment will be described. Examples of the non-aqueous electrolyte include a liquid non-aqueous electrolyte that is prepared by dissolving the electrolyte in an organic solvent, a gel non-aqueous electrolyte that is a composite of the liquid electrolyte and a polymer material, and the like. The liquid non-aqueous electrolyte can be prepared, for example, by dissolving the electrolyte in an organic solvent at a concentration of 0.5 mol / l or more and 2.5 mol / l or less.

Examples of the electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenide (LiAsF ₆ ), and trifluoromethanesulfone. Examples thereof include lithium salts such as lithium acid lithium (LiCF ₃ SO ₃ ) and bistrifluoromethylsulfonylimide lithium [LiN (CF ₃ SO ₂ ) ₂ ], or mixtures thereof. It is preferable that it is difficult to oxidize even at a high potential, and LiPF ₆ is most preferable.

  Examples of the organic solvent include cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), and vinylene carbonate, and chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and methyl ethyl carbonate (MEC). And cyclic ethers such as tetrahydrofuran (THF), 2-methyltetrahydrofuran (2MeTHF), dioxolane (DOX), chain ethers such as dimethoxyethane (DME) and dietoethane (DEE), γ-butyrolactone (GBL), acetonitrile ( AN) and sulfolane (SL). These organic solvents may be used alone or as a mixture of two or more.

  Examples of the polymer material include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), and the like.

  As the nonaqueous electrolyte, a room temperature molten salt (ionic melt) containing lithium ions, a polymer solid electrolyte, an inorganic solid electrolyte, or the like may be used.

  The nonaqueous electrolyte battery according to the second embodiment described above uses the electrode according to the first embodiment as at least one of a positive electrode and a negative electrode. Therefore, the self-discharge and internal short circuit of the battery can be suppressed.

Examples are shown below.
Example 1
As a negative electrode, an electrode was prepared in which a negative electrode active material-containing layer containing lithium titanate was provided on both surfaces (first surface and second surface) of a current collector made of aluminum foil. The average particle diameter of primary particles of lithium titanate was 0.5 μm. Moreover, the negative electrode active material content layer was not formed in the one end part parallel to the long side direction of a collector, and this location was made into the negative electrode current collection tab.

Disperse 100 parts by weight of Al ₂ O ₃ particles (particulate insulator) having an average particle diameter of 1 μm, 1 part by weight of carboxymethyl cellulose (CMC), and 4 parts by weight of an acrylic binder in water, Prepared. The obtained slurry was applied to the main surfaces (first surface and second surface) of each negative electrode active material-containing layer by spraying and dried, whereby a first having a thickness of 10 μm and a porosity of 60% was obtained. An insulating layer was formed.

  On this negative electrode, an organic fiber (fibrous insulator) layer was formed by electrospinning.

  Polyimide was used as the organic material. This polyimide was dissolved in DMAc as a solvent at a concentration of 20% by mass to prepare a raw material solution for forming an organic fiber layer. The obtained raw material solution was supplied to the side surface of the negative electrode from the spinning nozzle at a supply rate of 5 μl / min using a metering pump. Using a high voltage generator, a voltage of 20 kV was applied to the spinning nozzle, and an organic fiber layer was formed on the side surface of the negative electrode while moving the range of 100 × 200 mm with this spinning nozzle. The negative electrode current collector tab was subjected to electrospinning in a state where the surface of the negative electrode current collector tab was masked except for a 10 mm portion from the boundary with the negative electrode side surface, and the negative electrode having the structure shown in FIG. 3 was obtained. . On the surface of the outer edge portion of the active material-containing layer on the negative electrode side surface, the first insulating layer and the second insulating layer were in contact with each other to provide a connecting portion (first connecting portion).

  As a result of observation by SEM, the thickness of the formed organic fiber layer is 10 μm, the thickness of the organic fiber is 50 nm or less, and 40% of the total volume of the fiber forming the second insulating layer is the diameter. It was confirmed to be about 50 nm. Moreover, it was confirmed by mercury porosimetry that the porosity was 90%. From the length measurement by SEM and observation at the time of forming the fiber film, it is estimated that the length of the organic fiber is at least 1 mm or more.

  Next, a simple cell was produced using the produced negative electrode, and battery performance was evaluated.

  As the positive electrode, an electrode was prepared in which a positive electrode active material-containing layer containing lithium cobaltate was provided on a current collector made of aluminum foil.

  In the obtained first and second insulating layer integrated negative electrodes, the positive electrode is disposed so that the positive electrode active material-containing layer faces the negative electrode active material-containing layer through the first insulating layer, and these are formed into a flat shape. By pressing after winding, an electrode group having a flat spiral shape was obtained. After vacuum drying overnight at room temperature, it was left in a glove box with a dew point of −80 ° C. or lower for 1 day.

This was accommodated in a metal container together with the electrolytic solution to obtain a nonaqueous electrolyte battery of Example 1. The electrolyte used was one in which LiPF ₆ was dissolved in ethylene carbonate (EC) and dimethyl carbonate (DMC). Further, the nonaqueous electrolyte battery of Example 1 had the structure shown in FIG.
(Example 2)
A second insulating layer is deposited in the same manner as in Example 1 on the first insulating layer covering the first surface and the second surface of the negative electrode active material-containing layer from the short side to the width of 1 mm. A negative electrode having the same configuration as in Example 1 was produced except that the second connecting portion was formed. An electrode group was produced in the same manner as in Example 1 except that the negative electrode was wound from the side where the second connecting portion was present. A nonaqueous electrolyte battery was produced in the same manner as in Example 1 using the obtained electrode group.
(Examples 3 to 6)
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the types of the particulate insulator and the fibrous insulator were changed as shown in Table 1 below.
(Comparative Example 1)
An electrode group was produced in the same manner as in Example 1 except that the negative electrode side surface was covered with an insulating tape having a thickness of 20 μm instead of forming the second insulating layer. Since the thickness of the electrode group became thicker than the standard value, the electrode group could not be stored in the metal container. For this reason, the battery could not be manufactured.
(Comparative Example 2)
Containing Al ₂ O ₃ particles having the same composition as in Example 1 while forming an organic fiber layer on the entire negative electrode surface (excluding the surface of the negative electrode current collector tab) by electrospinning under the same conditions as in Example 1. The slurry was applied by spraying and dried to coat the entire negative electrode surface (excluding the surface of the negative electrode current collector tab) with a layer of organic fibers containing Al ₂ O ₃ particles. The thickness of the organic fiber layer was 10 μm, and the porosity was 60%. A non-aqueous electrolyte battery was produced in the same manner as in Example 1 using the obtained negative electrode.

  For the batteries of Examples 1 to 6 and Comparative Example 2, after removing defective products having a voltage of 0 V by an insulation test, the self-discharge amount (mAh / day) was measured by measurement using a potentiostat. The measurement conditions are as follows. The SOC (state of charge) before storage was 100%, the battery voltage was 2.7 V, the storage temperature was 25 ° C., and the storage time was 7 days. The percentage of non-defective products was measured assuming that the battery voltage after storage was less than 2 V, and the results are shown in Table 1 below.

  As is clear from Table 1, the non-defective product ratio in Examples 1 to 6 is higher than that in Comparative Example 2. This is because the first insulating layer is not peeled off or dropped off, and self-discharge due to leakage current is suppressed. The non-defective rate in Example 2 is the highest because the second insulating layer is deposited on the first insulating layer covering the end portion where the negative electrode starts to be wound.

  On the other hand, in Comparative Example 2 in which insulating particles were included in the organic fiber layer, the porosity of the organic fiber layer was higher than that of the first insulating layer. Became lower. Further, the formation rate of the organic fiber layer by the electrospinning method is about several tens of μl / min, whereas the formation rate of the first first insulating layer by slurry application is as high as about 100 μl / min. Therefore, the separator formation speed of Comparative Example 2 is slower than that of Examples 1 to 6, and it can be said that the electrode manufacturing methods of Examples 1 to 6 are excellent in productivity.

  According to the electrode of at least one embodiment and example described above, the first insulating layer covering the first surface and the second surface of the active material-containing layer and including a particulate insulator, Since it includes a second insulating layer that covers the surface of the outer edge portion of the electric body and includes a fibrous insulator, and a connecting portion where the first insulating layer and the second insulating layer are in contact with each other, the self-discharge of the battery is prevented. Can be suppressed.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Electrode, 2 ... Current collector, 3 ... Current collection tab, 4a, 4b ... Active material containing layer, 5a, 5b ... 1st insulating layer, 6, 6a, 6b, 8 ... 2nd insulating layer, 7 DESCRIPTION OF SYMBOLS ... Connection part, 10 ... Battery, 11 ... Exterior member, 12 ... Electrode group, 13 ... Positive electrode terminal, 14 ... Negative electrode terminal, 15 ... Positive electrode, 15a ... Positive electrode collector, 15b ... Positive electrode active material containing layer, 15c ... Positive electrode Current collector tab, 16 ... negative electrode, 16a ... negative electrode current collector, 16b ... negative electrode active material containing layer, 16c ... negative electrode tab, 20 ... container, 21 ... electrode group, 22 ... lid, 23 ... positive electrode terminal, 24 ... negative electrode terminal 25 ... positive electrode, 26 ... negative electrode, 27 ... negative electrode current collecting tab, 28 ... positive electrode lead, 29 ... negative electrode lead, 30 ... organic fiber layer.

Claims (5)

A current collector having an outer edge;
An active material-containing layer formed on at least a part of the surface of the current collector excluding the outer edge, and having a first surface and a second surface;
A first insulating layer covering the first surface and the second surface of the active material-containing layer and including a particulate insulator;
A second insulating layer that covers a surface of the outer edge of the current collector and includes a fibrous insulator;
An electrode comprising: the first insulating layer and a connecting portion in contact with the second insulating layer.   The electrode according to claim 1, wherein the connecting portion is located on a surface of an outer edge portion of the active material-containing layer.   The connecting portion includes a portion in which the second insulating layer is formed on the first insulating layer covering one end of each of the first surface and the second surface of the active material-containing layer, The electrode according to claim 1 or 2. An insulating layer that includes a current collector having an outer edge and an active material-containing layer formed on at least a part of the surface of the current collector excluding the outer edge and having a first surface and a second surface. Preparing a forming electrode;
Applying a slurry containing a particulate insulator and a binder to the first surface and the second surface of the active material-containing layer to obtain a first insulating layer by drying;
Including the step of obtaining a second insulating layer by forming a fibrous insulator directly on the surface of the outer edge of the current collector at the same time as or different from the step of obtaining the first insulating layer. The manufacturing method of the electrode of any one of Claims 1-3. A positive electrode;
A negative electrode comprising the electrode according to claim 1;
A non-aqueous electrolyte battery comprising a non-aqueous electrolyte.