JP2004221064A - Electrochemical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently provide an electrochemical element having a simple structure, high reliability, and a high electrical capacitance. <P>SOLUTION: This electrochemical element is a secondary battery having a group of electrodes 10 composed of (a) at least one first electrode 15a, (b) at least one second electrode 15b, and (c) a separator 16 intervening between the first electrode and the second electrode. The first electrode (a) is composed of a fist collector sheet 13a having a conductive part and an insulating part and at least one first electrode mix layer 14a carried by the sheet, and the second electrode (b) is composed of a second collector sheet 13b having a conductive part and an insulating part and at least one second electrode mix layer 14b carried by the sheet. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an electrochemical device, and more particularly to an improvement in an electrode group of a secondary battery having a high energy density such as a lithium ion secondary battery.

  With the miniaturization and weight reduction of electronic and electric devices, demands for miniaturization and weight reduction of secondary batteries are increasing. On the other hand, the current secondary battery has a complicated internal structure, and there is a limit to improving the electric capacity of a product per fixed volume. In addition, the complicated structure hinders the improvement of battery reliability. For example, a current collecting tab or a current collecting lead connected to the electrode may prevent a uniform electrode reaction on the electrode surface. Also, if metal burrs larger than usual occur on the cut surface of the lead, there is a concern that an internal short circuit may occur.

  The secondary battery has an electrode group including a positive electrode, a negative electrode, and a separator. The electrode group includes a stacked type and a wound type. A stacked electrode plate group is obtained by alternately stacking a positive electrode and a negative electrode via a separator. Further, the wound electrode group is obtained by winding a long positive electrode and a negative electrode via a separator. These electrode plates usually have side surfaces on which the ends of the positive electrode and the negative electrode are arranged flush. In order to extract electricity from such a side without causing a short circuit, a current collecting tab and a current collecting lead are required.

Therefore, from the viewpoint of simplifying the internal structure of the battery, the positive electrode protrudes from one of the side surfaces of the electrode plate group, and the negative electrode protrudes from the side surface opposite to the side surface. Instead, it is proposed to extract electricity directly from each side. For example, in a battery having a stacked electrode plate group, a technique has been proposed in which protruded electrode plates of the same polarity are integrally joined using a predetermined metal member (for example, see Patent Document 1). Further, in a battery having a wound electrode group, a technique has been proposed in which a protruding electrode material having the same polarity is joined to a plate-shaped current collector plate (for example, see Patent Document 2). .
JP 2001-126707 A JP 2000-294222 A

  However, in the case where the positive electrode protrudes from one of the side surfaces of the electrode group and the negative electrode protrudes from the side surface opposite to the side surface, the electrode groups must be manufactured one by one. The process becomes complicated. That is, there is a problem that a plurality of electrode plate groups cannot be simultaneously manufactured.

  The present invention relates to an electric power having an electrode group including (a) at least one first electrode, (b) at least one second electrode, and (c) a separator interposed between the first electrode and the second electrode. A chemical element, wherein the first electrode (a) comprises a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer carried on the first current collector sheet; The electrode (b) relates to an electrochemical device comprising a second current collector sheet having a conductive portion and an insulating portion and at least one second electrode mixture layer carried on the second current collector sheet.

The conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group, and the conductive portion of the second current collector sheet is a second terminal on a second side surface of the electrode plate group. Preferably, the insulating portion of the first current collector sheet is provided on the second side surface, and the insulating portion of the second current collector sheet is provided on the first side surface.
An insulating portion of the first current collector sheet and an insulating portion of the second current collector sheet may be arranged on the side surfaces of the electrode plate group other than the first side surface and the second side surface.

That is, the electrode group includes a side surface on which the insulating portion of the first current collector sheet and / or the insulating portion of the second current collector sheet are arranged, in addition to the first side surface and the second side surface. Can have.
It is preferable that the first side surface and the second side surface are located on opposite sides of the electrode plate group.

  A first insulating material portion for insulating the first terminal and the second electrode may be provided on the first side surface. Further, a second insulating material portion for insulating the second terminal and the first electrode can be provided on the second side surface.

  The present invention is also an electrochemical device having a wound electrode plate group in which a first electrode and a second electrode are wound with a separator interposed therebetween, wherein the first electrode includes a conductive portion and an insulating portion. Comprising a first current collector sheet having at least one first electrode mixture layer supported thereon, wherein the second electrode has a second current collector sheet having a conductive portion and an insulating portion and is supported by the second current collector sheet. And a conductive portion of the first current collector sheet is connected to a first terminal on a first bottom surface of the electrode plate group, and a conductive portion of the second current collector sheet is formed. Is connected to a second terminal on a second bottom surface of the electrode plate group, an insulating portion of the first current collector sheet is arranged on the second bottom surface, and an insulating portion of the second current collector sheet is connected to the first terminal. The present invention relates to an electrochemical device arranged on a bottom surface.

  The present invention is also an electrochemical device having a wound electrode plate group in which a first electrode and a second electrode are wound with a separator interposed therebetween, wherein the first electrode includes a conductive portion and an insulating portion. Comprising a first current collector sheet having at least one first electrode mixture layer supported thereon, wherein the second electrode has a second current collector sheet having a conductive portion and an insulating portion and is supported by the second current collector sheet. And a conductive portion of the first current collector sheet is connected to a first terminal on a first bottom surface of the electrode plate group, and a conductive portion of the second current collector sheet is formed. Is connected to a second terminal on a second bottom surface of the electrode plate group, an insulating portion of the first current collector sheet is arranged on the second bottom surface, and an insulating portion of the second current collector sheet is connected to the first terminal. A first bottom surface for insulating the first terminal and the second electrode from each other; And an insulating material part is provided, wherein the second bottom surface, an electrochemical device in which the second insulating material portion for insulating the first electrode and the second terminal is provided.

  The present invention is also an electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween, wherein the plurality of first electrodes are each a conductive part. A first current collector sheet having at least one first electrode mixture layer supported on the first current collector sheet, and a plurality of second electrodes each having a conductive portion and an insulating portion. An electrical conductor sheet and at least one second electrode mixture layer carried on the electrical conductor sheet, wherein a conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group; A conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode group; an insulating portion of the first current collector sheet is disposed on the second side surface; The present invention relates to an electrochemical device in which an insulating portion of a sheet is disposed on the first side surface.

  The present invention is also an electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween, wherein the plurality of first electrodes are each a conductive part. A first current collector sheet having at least one first electrode mixture layer supported on the first current collector sheet, and a plurality of second electrodes each having a conductive portion and an insulating portion. An electrical conductor sheet and at least one second electrode mixture layer carried on the electrical conductor sheet, wherein a conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group; A conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode group; an insulating portion of the first current collector sheet is disposed on the second side surface; An insulating portion of the sheet is disposed on the first side surface, and the first side surface has the A first insulating material portion for insulating the terminal from the second electrode is provided, and a second insulating material portion for insulating the second terminal from the first electrode is provided on the second side surface. The present invention relates to an electrochemical device provided with:

  The present invention is also an electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween, wherein the plurality of first electrodes are each a conductive part. A first current collector sheet having at least one first electrode mixture layer supported on the first current collector sheet, and a plurality of second electrodes each having a conductive portion and an insulating portion. An electrical conductor sheet and at least one second electrode mixture layer carried on the electrical conductor sheet, wherein a conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group; (2) The conductive portion of the current collector sheet is connected to the second terminal on the second side surface of the electrode plate group, and the insulating portion of the first current collector sheet is provided on all side surfaces other than the first side surface of the electrode plate group. An insulating portion of the second current collector sheet is disposed on the second side of the electrode plate group. An electrochemical element which is arranged on all sides except.

  The present invention is also an electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween, wherein the plurality of first electrodes are each a conductive part. A first current collector sheet having at least one first electrode mixture layer supported on the first current collector sheet, and a plurality of second electrodes each having a conductive portion and an insulating portion. An electrical conductor sheet and at least one second electrode mixture layer carried on the electrical conductor sheet, wherein a conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group; (2) The conductive portion of the current collector sheet is connected to the second terminal on the second side surface of the electrode plate group, and the insulating portion of the first current collector sheet is provided on all side surfaces other than the first side surface of the electrode plate group. An insulating portion of the second current collector sheet is disposed on the second side of the electrode plate group. The first side surface is provided with a first insulating material portion for insulating the first terminal from the second electrode, and the second side surface includes the first insulating material portion. The present invention relates to an electrochemical device provided with a second insulating material portion for insulating two terminals and the first electrode.

  It is preferable that the first current collector sheet and the second current collector sheet each include a resin sheet and a conductive layer provided on the surface thereof. In addition, the insulating portions of the first current collector sheet and the second current collector sheet each include one end of a resin sheet, and the conductive portions of the first current collector sheet and the second current collector sheet. Is preferably composed of respective conductive layers.

  The first terminal and the second terminal can be provided by, for example, disposing a metal coating on the first side surface and the second side surface, respectively. The insulating part of the first current collector sheet can be fixed to the second terminal, and the insulating part of the second current collector sheet can be fixed to the first terminal.

  ADVANTAGE OF THE INVENTION According to this invention, the structure of a positive electrode terminal and a negative electrode terminal is simple, and it is not necessary to use a current collection tab or a current collection lead. Therefore, it is possible to provide an electrochemical device having a small size, a simple structure, high reliability, and high electric capacity. Further, according to the present invention, a plurality of electrochemical devices can be efficiently manufactured at the same time.

  FIG. 1 shows a longitudinal sectional view of an example of a laminated electrode group according to the present invention. The electrode plate group 10 includes a plurality of first electrodes 15a and a plurality of second electrodes 15b that are alternately stacked, and a separator 16 is interposed between the first electrodes 15a and the second electrodes 15b. .

  The first electrode 15a includes a first current collector sheet 13a and two first electrode mixture layers 14a. The first current collector sheet 13a has a predetermined shape pattern provided on the resin sheet 11a and both surfaces thereof. Of the conductive layer 12a. That is, the first current collector sheet 13a has a conductive portion and an insulating portion according to the shape pattern of the conductive layer.

  In FIG. 1, the conductive layer is provided on the entire surface except for one end 11x of the resin sheet or on the entire surface except for the end 11x and the end located on the front and back of FIG. The first electrode mixture layer is provided on the conductive layer. In the first current collector sheet of FIG. 1, the end 11x or the end 11x of the resin sheet having no conductive layer and the end located on the front and back of FIG. 1 function as an insulating portion. An exposed portion of the conductive layer is left at an end 12x of the conductive layer located on the opposite side of the end 11x.

  The thickness of the resin sheet is preferably, for example, 0.5 to 500 μm. Further, the thickness of the conductive layer is preferably 0.01 to 100 μm. The thickness of the first electrode mixture layer is not particularly limited, but is preferably, for example, 1 to 1000 μm.

  Examples of the resin sheet include olefin-based polymers such as polyethylene, polypropylene, and polymethylpentene; ester-based polymers such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, and polyarylate; and thioether-based polymers such as polyphenylene sulfide. Polymers, aromatic vinyl polymers such as polystyrene, nitrogen-containing polymers such as polyimide and aramid resin, and fluoropolymers such as polytetrafluoroethylene and polyvinylidene fluoride can be used. These may be used alone, or a copolymer, a polymer alloy, a polymer blend or the like in which two or more kinds are combined may be used.

  A normal resin sheet having a flat surface may be used, or a perforated body, lath body, porous body, net, foam, woven fabric, nonwoven fabric, or the like may be used. Alternatively, a resin sheet having irregularities on the surface can be used.

  For the conductive layer, an electronic conductor that does not cause a chemical change in the configured battery can be used without particular limitation. When the first electrode is a positive electrode, for example, stainless steel, aluminum, an aluminum alloy, titanium, carbon, or the like can be used, and particularly, aluminum, an aluminum alloy, or the like is preferable. When the first electrode is a negative electrode, for example, stainless steel, nickel, copper, a copper alloy, titanium, or the like can be used, and particularly, copper, a copper alloy, or the like is preferable.

  The method for forming the conductive layer is not particularly limited. For example, the conductive layer can be formed by depositing a conductive material on a resin sheet. At that time, it is preferable to perform the vapor deposition after covering the resin sheet with a mask having an opening of a predetermined shape so that a vapor deposition film having a predetermined shape pattern is formed.

  The electrode group of FIG. 1 includes two types of second electrodes 15b and 15b '. The inner second electrode 15b sandwiched between the two first electrodes 15a has the same structure as the first electrode 15a, except that the arrangement in the electrode group is reversed. That is, the inner second electrode 15b is composed of the second current collector sheet 13b and the two second electrode mixture layers 14b, and the second current collector sheet 13b is formed of the resin sheet 11b and the predetermined surfaces provided on both surfaces thereof. Of the conductive layer 12b having the following shape pattern. The second current collector sheet has a conductive part and an insulating part according to the shape pattern of the conductive layer.

  In the second current collector sheet of FIG. 1, the end 11y of the resin sheet having no conductive layer or the end 11y and the end located on the front and back of FIG. 1 function as an insulating portion. An exposed portion of the conductive layer is left at an end 12y of the conductive layer located on the opposite side of the end 11y.

  On the other hand, the outermost two second electrodes 15b 'are the same as the inner second electrodes except that the conductive layer 12b and the second electrode mixture layer 14b are provided on one surface, not on both surfaces of the resin sheet 11b. It has the structure of

  The exposed portion of the conductive layer of the first current collector sheet is disposed on the first side surface of the electrode plate group, that is, on the left side of FIG. 1. That is, they are arranged on the right side of FIG. In FIG. 1, the first side surface and the second side surface are located on opposite sides of the electrode plate group, but the arrangement of the first side surface and the second side surface is not limited to this. . On the other hand, the exposed portion of the conductive layer of the second current collector sheet is disposed on the first side surface of the electrode plate group, and the insulating portion on the opposite side is disposed on the second side surface of the electrode plate group. I have.

  That is, in FIG. 1, the first electrode and the second electrode having the same structure are arranged in opposite directions. Therefore, the exposed portion of the conductive layer of the first current collector sheet is adjacent to the insulating portion of the second current collector sheet, and the exposed portion of the conductive layer of the second current collector sheet is formed of the first current collector sheet. Adjacent to the insulation. With such an arrangement, it is easy to prevent a short circuit between the first electrode and the second electrode. In addition, it is easy to connect the exposed portions of the conductive layers of the plurality of first current collector sheets or the second current collector sheets to each other and obtain a high-capacity battery connected in parallel. However, from the viewpoint of reliably preventing a short circuit, it is preferable to provide the electrode with an insulating portion having a width of 0.001 mm or more, preferably 0.1 mm or more.

  The exposed portions of the conductive layers of the plurality of first current collector sheets and the second current collector sheets may be connected by any method. For example, as shown in FIG. 1, a method of covering the first side surface and the second side surface with a conductive material can be preferably used. The thickness of the coating of the conductive material is, for example, about 0.01 to 1 mm. In this case, the conductive material can be used as the first terminal 17a or the second terminal 17b while connecting the conductive material to the exposed portion of the conductive layer. In order to obtain a good current collection state, it is preferable that the contact area between the exposed portion of the conductive layer and the conductive material is large, and the exposed portion of the conductive layer has a thickness of 0.001 to 1 mm inside the coating of the conductive material. It is preferable to penetrate to the depth.

  Between the first terminal and the first side surface and between the second terminal and the second side surface, a first insulating material portion 18a for insulating the first terminal from the second electrode and a second insulating material are provided. It is preferable that the material portion 18b is provided. Since the insulating portion of the second current collector sheet is disposed on the first side surface and the insulating portion of the first current collector sheet is disposed on the second side surface, short-circuiting can be performed without providing an insulating material portion. It is easy to prevent this, but the reliability of the secondary battery is greatly improved by providing the insulating material portion. The thickness of the insulating material portion is not particularly limited, but is preferably 0.001 mm or more, and more preferably 0.01 mm or more.

  The method for forming the insulating material portion is not particularly limited, but the insulating material portion can be formed by, for example, applying a paste or liquid insulating material to a predetermined position by a screen printing method. Further, the insulating material portion can be formed by attaching a film-shaped or tape-shaped insulating material to a predetermined position.

  Examples of the insulating material used for the insulating material portion include a thermoplastic resin, a thermosetting resin, a glass composition, and a ceramic. Further, a composite material in which a woven fabric or a nonwoven fabric is impregnated with a resin can be used. When a thermosetting resin is used, a step of heating and curing the resin coating film is required.

  Examples of resins that can be used for the insulating material portion include olefin-based polymers such as polyethylene, polypropylene, and polymethylpentene; polyethylene-based terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyarylate, and ester-based polymers such as polycarbonate; Ether polymers such as ethylene oxide, polypropylene oxide, polyacetal, polyphenylene ether, polyetheretherketone, and polyetherimide; sulfone polymers such as polysulfone and polyethersulfone; acrylonitrile polymers such as polyacrylonitrile, AS resin and ABS resin; and polyphenylene Thioether polymers such as sulfide, aromatic vinyl polymers such as polystyrene Chromatography, polyimide, nitrogen-containing polymer, such as aramid resin, polytetrafluoroethylene, fluorine polymers such as polyvinylidene fluoride, acrylic polymers such as polymethyl methacrylate and the like. These may be used alone, or a copolymer, a polymer alloy, a polymer blend or the like in which two or more kinds are combined may be used. Further, a polymer obtained by polymerization and solidification by heating or UV irradiation may be used.

  In FIG. 1, the second electrode mixture layer has a larger area than the first electrode mixture layer. In the case of a lithium ion secondary battery, it is preferable to adopt such a structure in which the first electrode mixture layer is used as a positive electrode and the second electrode mixture layer is used as a negative electrode. On the other hand, when the first electrode mixture layer is a negative electrode and the second electrode mixture layer is a positive electrode, the area of the first electrode mixture layer is preferably larger than that of the second electrode mixture layer.

Next, an example of a method for manufacturing a laminated electrode group will be described with reference to FIG.
(A) Preparation of First Electrode First, a resin sheet 21a large enough to provide a desired number of current collector sheets is prepared. Next, a plurality of conductive layers having a predetermined shape pattern are provided at the same position on both surfaces of the resin sheet 21a. For example, conductive layers of a predetermined shape are formed on a resin sheet in a plurality of rows and a plurality of columns as shown in FIG. Such a conductive layer can be obtained, for example, by covering a resin sheet with a mask having a matrix-shaped opening and vapor-depositing metal on the resin sheet portion exposed from the opening.

  Here, a case where one conductive layer is formed so as to straddle two current collector sheets will be described. That is, when a resin sheet having a size capable of providing 2n current collector sheets is used, n conductive layers are formed on one surface of the resin sheet.

  Next, two first electrode mixture layers 22a are formed on each conductive layer. An exposed portion 23a of the conductive layer having no mixture is left between the two first electrode mixture layers. Although FIG. 2 illustrates the electrode mixture layers in three rows and three columns, usually, more conductive layers and electrode mixture layers are formed on a larger current collector sheet.

  The first electrode mixture layer is formed by applying a paste made of the first electrode mixture to the entire surface of the conductive layer except for the central portion. The coating method is not particularly limited, but it is preferable to adopt screen printing, pattern coating, or the like. At this time, the exposed portion of the conductive layer on which the paste made of the mixture has not been applied becomes a connection portion 24a to the first terminal after the electrode plate group is formed.

  The first electrode mixture is prepared by mixing an active material of the first electrode, a conductive material, a binder and the like with a dispersion medium. Thereafter, the paste coating is dried, and the dried coating is rolled with a roller to increase the mixture density.

When the first electrode is the positive electrode of a lithium ion secondary battery, for example, a lithium-containing transition metal oxide can be preferably used as the active material. Examples of the lithium-containing transition metal oxides, for _{example, Li x CoO z, Li x} NiO z, Li x MnO z, Li x Co y Ni 1-y O z, Li x Co f V 1-f O z, Li x _{Ni 1-y M y O z} (M = Ti, V, Mn, Fe), Li x Co a Ni b M c O z (M = Ti, Mn, Al, Mg, Fe, Zr), Li x Mn 2 O ₄ , Li _x Mn _{2 (1-y)} M _2y O ₄ (M = Na, Mg, Sc, Y, Fe, Co, Ni, Ti, Zr, Cu, Zn, Al, Pb, Sb) and the like be able to. However, the x value changes in the range of 0 ≦ x ≦ 1.2 due to charging and discharging of the battery. Also, 0 ≦ y ≦ 1, 0.9 ≦ f ≦ 0.98, 1.9 ≦ z ≦ 2.3, a + b + c = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, and 0 ≦ c <1. is there. These may be used alone or in combination of two or more.

  When the first electrode is a negative electrode of a lithium ion secondary battery, examples of the active material include lithium, a lithium alloy, an intermetallic compound, a carbon material, an organic compound or an inorganic compound capable of inserting and extracting lithium ions, and a metal complex. And an organic polymer compound can be preferably used. These may be used alone or in combination of two or more.

  Carbon materials include coke, pyrolytic carbon, natural graphite, artificial graphite, mesocarbon microbeads, graphitized mesophase microspheres, vapor-grown carbon, glassy carbon, carbon fibers (polyacrylonitrile, pitch, cellulose, Vapor-phase growth system), amorphous carbon, and an organic compound fired body. Among these, natural graphite and artificial graphite are particularly preferred.

  As the conductive material, for example, carbon black such as acetylene black, graphite, or the like is used. Further, as the binder, for example, a fluororesin such as polyvinylidene fluoride and polytetrafluoroethylene, an acrylic resin, styrene butadiene rubber, ethylene propylene terpolymer and the like can be used.

  Next, an insulating material is applied along the peripheral portion of the first electrode mixture layer that is adjacent to the exposed portion of the conductive layer of the second current collector sheet when the electrode plate group is formed. Here, it is preferable to perform pattern coating. Other portions of the peripheral portion of the first electrode mixture layer may be coated with an insulating material, but the entire exposed portion of the conductive layer of the first current collector sheet is not covered. When obtaining the electrode plate group as shown in FIG. 1, an insulating material is applied to at least the side of the peripheral portion of the first electrode mixture layer opposite to the exposed portion of the conductive layer. The application of the insulating material is not always necessary, and may be arbitrarily performed. The insulating resin applied here forms the first insulating material portion in the electrode plate group.

(B) Preparation of second electrode The second electrode having the second electrode mixture layers on both surfaces can be prepared in the same manner as the first electrode. That is, a plurality of conductive layers of a predetermined shape pattern are provided at the same position on both sides of a resin sheet 21b having a size capable of providing a desired number of current collector sheets, and a second electrode mixture layer is provided on each conductive layer. 22b are formed two by two. An exposed portion 23b of the conductive layer having no mixture is left between the two second electrode mixture layers. At this time, the exposed portion of the conductive layer on which the paste made of the mixture has not been applied becomes a connection portion 24b with the second terminal after the electrode group is formed. In addition, the second electrode having the second electrode mixture layer only on one side is manufactured in the same manner as described above, except that the conductive layer, the second electrode mixture layer, and the insulating material are not provided on the other side. Can be.

(C) Manufacture of Electrode Plate Group The manufactured assembly composed of a plurality of first electrodes and the assembly composed of a plurality of second electrodes are laminated via a separator. At this time, these are laminated so that the first electrode mixture layer 22a of the first electrode and the second electrode mixture layer 22b of the second electrode face each other. In addition, the bipolar plate is arranged such that the exposed portion 23a of the conductive layer and the insulating material in the first electrode face the insulating material and the exposed portion 23b of the conductive layer in the second electrode, respectively. Then, on both outermost surfaces, a pair of second electrodes having a second electrode mixture layer only on one side are arranged, the inner electrodes are sandwiched by these, and the whole is pressed. As a result, an assembly including a plurality of electrode plate stacks is obtained.

  A woven or nonwoven fabric made of an olefin polymer such as polyethylene or polypropylene, glass fiber, or the like can be used for the separator. Further, a solid electrolyte or a gel electrolyte can be used as the separator.

  For the solid electrolyte, for example, polyethylene oxide, polypropylene oxide, or the like can be used as a matrix material. As the gel electrolyte, for example, a gel electrolyte in which a non-aqueous electrolyte solution described later is held in a matrix made of a polymer material can be used. As the polymer material forming the matrix, polyethylene oxide, polypropylene oxide, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, or the like can be used. These may be used alone or in combination of two or more. Among these, it is particularly preferable to use a copolymer of vinylidene fluoride and hexafluoropropylene, or a mixture of polyvinylidene fluoride and polyethylene oxide.

  Next, an assembly including a plurality of electrode stacks is divided for each electrode stack. At this time, the first electrode and the second electrode are cut along the arrow direction shown in FIG. The cut portions of the current collector sheet corresponding to the exposed portions of the conductive layer become the connection portions 24a and 24b to the terminals, and the cut portions 25a and 25b corresponding to the exposed portions of the resin sheet on the opposite side become the insulating portions.

  In the case of a current collector made of a metal foil that has been generally used in the past, metal burrs generated during cutting pose a problem. This is because metal burrs break through the separator and are a major cause of causing an internal short circuit. Therefore, it is important to prevent the generation of metal burrs, but it is extremely difficult to cut the metal foil without generating metal burrs. On the other hand, when a current collector sheet made of a resin sheet is used, since most of the cut surface is occupied by the resin, metal burrs do not occur. Therefore, the reliability of the electrochemical device can be greatly improved.

  Next, a side surface on which the exposed portions of the conductive layer of the first current collector sheet and the insulating portions of the second current collector sheet are alternately arranged is covered with a metal. For example, the side surface can be coated with a metal by spraying molten or semi-molten metal fine particles on the side surface. Since the insulating material is applied to the end surface of the second electrode on the side surface, a short circuit between the metal film and the second electrode does not occur. The metal film thus formed is electrically connected only to the exposed portion of the conductive layer of the first current collector sheet. The side surface on which the exposed portions of the conductive layer of the second current collector sheet and the insulating portions of the first current collector sheet are alternately arranged is also covered with metal in the same manner as described above.

  Here, when the terminal is a positive electrode terminal, it is preferable to use aluminum powder as the metal fine particles. When the terminal is a negative electrode terminal, it is preferable to use copper powder as the metal fine particles.

  The metal film electrically connected to the conductive layer of the first current collector sheet and the metal film electrically connected to the conductive layer of the second current collector sheet serve as a first terminal and a second terminal, respectively. Function. On the other hand, the side surface of the electrode group having no terminal may be left as it is, but it is preferable that the side surface is covered with a porous insulating material if possible.

  An assembly of electrode plates can also be obtained using an assembly consisting of a plurality of first electrodes and an assembly consisting of a plurality of second electrodes as shown in FIG. When obtaining such an aggregate including the first electrodes, a plurality of rows of strip-shaped conductive layers are formed at the same position on both surfaces of the resin sheet 31a having a size capable of providing a desired number of current collector sheets. Such a conductive layer can be obtained, for example, by covering a resin sheet with a mask having a strip-shaped opening and depositing a metal on the resin sheet portion exposed from the opening. Also in this case, one strip-shaped conductive layer is formed so as to straddle two strip-shaped current collector sheets. That is, when a resin sheet having a size capable of providing 2n strip-shaped current collector sheets is used, n strip-shaped conductive layers are formed on one surface of the resin sheet.

  Next, two strip-shaped first electrode mixture layers 32a are formed on each strip-shaped conductive layer. An exposed portion 33a of the conductive layer having no mixture is left between the two band-shaped first electrode mixture layers 32a. The strip-shaped first electrode mixture layer 32a is formed by applying a paste made of the same first electrode mixture as described above to the entire surface of the conductive layer except for the central portion. The coating method is the same as in the case of the laminated electrode group. At this time, the exposed portion 33a of the conductive layer on which the paste is not applied becomes a connection portion 34a with the first terminal.

  Further, when obtaining an aggregate composed of the second electrodes, a plurality of rows of strip-shaped conductive layers are provided at the same position on both surfaces of the resin sheet 31b having a size capable of providing a desired number of current collector sheets. Two strip-shaped second electrode mixture layers 32b are formed on each. An exposed portion 33b of the conductive layer having no mixture is left between the two band-shaped second electrode mixture layers. At this time, the exposed portion of the conductive layer on which the paste made of the mixture is not applied becomes a connection portion 34b with the second terminal after the electrode group is formed.

  When such an assembly of electrode plates is divided for each electrode plate stack in the direction of the arrow shown in FIG. 3, the cut portion of the current collector sheet corresponding to the exposed portion of the conductive layer is connected to the terminal. The cut portions 35a and 35b corresponding to the exposed portions of the resin sheet on the opposite side become the insulating portions, and the cross sections of the mixture are exposed at the other cut portions. In this case, it is preferable to seal the side surface of the electrode plate group from which the cross section of the mixture is exposed with a porous insulating material.

  The electrode plate group according to the present invention is accommodated in a case having a predetermined shape together with a predetermined electrolyte as needed. As the case, for example, a stainless steel plate, an aluminum plate or the like processed into a predetermined shape, an aluminum foil (aluminum laminated sheet) having a resin coating on both surfaces, a resin case, or the like is used. The shape and material of the case are not particularly limited. The electrolytic solution varies depending on the type of the battery, but when the electrochemical element is a lithium ion secondary battery, a solution obtained by dissolving a lithium salt in a non-aqueous solvent is used as the electrolytic solution. The lithium salt concentration in the electrolytic solution is preferably, for example, 0.5 to 1.5 mol / L.

  Non-aqueous solvents include non-aqueous solvents such as ethylene carbonate, propylene carbonate, butylene carbonate, and cyclic carbonates such as vinylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethyl propyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, and dipropyl carbonate. Aliphatic carbonates such as cyclic carbonate, methyl formate, methyl acetate, methyl propionate and ethyl propionate; γ-lactones such as γ-butyrolactone and γ-valerolactone; 1,2-dimethoxyethane; Acyclic ethers such as ethoxyethane and ethoxymethoxyethane, cyclic ethers such as tetrahydrofuran and 2-methyl-tetrahydrofuran, dimethylsulfoxy , 1,3-dioxolane, trimethyl phosphate, triethyl phosphate, alkyl phosphate esters and their fluorides, such as trioctyl phosphate can be used. These are preferably used in combination of a plurality of types. In particular, a mixture containing a cyclic carbonate and an acyclic carbonate, a mixture containing a cyclic carbonate, an acyclic carbonate, and an aliphatic carboxylic acid ester are preferable.

Lithium salts include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAlCl ₄ , LiSbF ₆ , LiSCN, LiCl, LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiN (CF ₃ SO ₂ ) ₂ , Li ₂ B ₁₀ Cl ₁₀ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiPF ₃ (CF ₃ ) ₃ , LiPF ₃ (C ₂ F ₅ ) _{3 and the} like can be used. These may be used alone or in combination of two or more, but it is preferable to use at least LiPF6.

  According to the above-described manufacturing method, for example, an electrode group having an arbitrary size can be efficiently manufactured within a range of 1 to 300 mm in length, 1 to 300 mm in width, and 0.01 to 20 mm in thickness. .

  Next, an example of a method for manufacturing a wound electrode group according to the present invention will be described. FIG. 4 is a partial conceptual diagram of the wound electrode group drawn around the first electrode, and further, the outermost mixture layer, the electrode plate, and the like are omitted.

(A) Production of first electrode and second electrode The first electrode and the second electrode used for the wound electrode group have a strip shape, and the first electrode and the second electrode used for the stacked electrode group are different from each other. It has the same structure as the electrodes. Therefore, the manufacturing method of the first electrode and the second electrode is almost the same as the case of the stacked type. For example, the same aggregates of the first electrode and the second electrode as shown in FIG. 3 are manufactured. Next, in the same manner as described above, an insulating material is applied on at least the side of the peripheral portion of the electrode mixture layer opposite to the exposed portion side of the conductive layer. This portion is adjacent to the exposed portion of the conductive layer of the counter electrode in the electrode plate group.

(B) Preparation of Electrode Group An assembly made of the first electrode and an assembly made of the second electrode are wound via the separator 40. At this time, the electrodes are arranged such that the strip-shaped first electrode mixture layer 32a and the second electrode mixture layer 32b face each other. The bipolar plates are arranged such that the exposed portion of the conductive layer and the insulating material of the first electrode face the insulating material and the exposed portion of the conductive layer of the second electrode, respectively. As a result, a long cylindrical aggregate composed of a plurality of wound electrode plates that are alternately arranged in the opposite direction is obtained.

  Next, the long cylindrical aggregate is divided for each electrode plate group. On one side surface (bottom surface) of such an electrode plate group, exposed portions of the conductive layer of the first current collector sheet and insulating portions of the second current collector sheet are alternately and concentrically arranged. On the other side (bottom), exposed portions of the conductive layer of the second current collector sheet and insulating portions of the first current collector sheet are alternately and concentrically arranged.

  Covering the bottom surface where the exposed portions of the conductive layers of the first current collector sheet are arranged and the bottom surface where the exposed portions of the conductive layers of the second current collector sheet are arranged with metal in the same manner as described above. Thereby, the first terminal 41 and the second terminal 42 can be formed.

  As described above, by applying an insulating material to the end face of the second electrode on the first terminal side, a short circuit between the metal film and the second electrode can be reliably prevented, and the first electrode on the second terminal side can be prevented. By coating the end face with an insulating material, a short circuit between the metal film and the first electrode can be reliably prevented.

In this example, a stacked lithium ion secondary battery was manufactured in the following manner.
(A) Preparation of First Electrode A sheet of polyethylene terephthalate (hereinafter referred to as PET) having a width of 198 mm, a length of 282 mm, and a thickness of 7 μm was prepared. Next, a plurality of rectangular (65 mm × 46 mm) copper vapor-deposited films arranged in three rows and six columns were formed at the same position on both sides of the PET sheet using a mask having a matrix-shaped opening. The thickness of the copper deposition film was 0.1 μm.

  Next, 100 parts by weight of spherical graphite (graphitized mesophase small spheres) as an active material, 3 parts by weight of styrene-butadiene rubber as a binder, and an appropriate amount of a carboxymethylcellulose aqueous solution as a dispersion medium are mixed to form a first mixture. A paste comprising the electrode mixture was prepared. Then, the paste was applied to the entire surface except for the central part of each vapor-deposited film. As a result, two 32 mm x 46 mm first electrode mixture layers were formed on each of the deposited films. Between the two first electrode mixture layers, an exposed portion of a copper vapor-deposited film having no mixture was left in a groove shape having a width of 1 mm. Thereafter, the coating film of the paste was dried, and the dried coating film was rolled with a roller until the thickness became 70 μm.

  Next, in the peripheral portion of the first electrode mixture layer, a portion opposite to the portion adjacent to the exposed portion of the deposited film was coated with polyvinylidene fluoride having a width of 0.3 mm as an insulating material. Thus, an assembly of first electrodes having first electrode mixture layers in 6 rows and 6 columns on both surfaces was obtained.

(B) Preparation of second electrode A PET sheet having a width of 198 mm, a length of 282 mm, and a thickness of 7 μm was prepared. Next, a plurality of rectangular (64 mm × 45 mm) aluminum vapor-deposited films arranged in three rows and six columns were formed at the same position on both sides of the PET sheet using a mask having a matrix-shaped opening. The thickness of the Al deposited film was 0.1 μm.

Next, 100 parts by weight of lithium cobalt oxide (LiCoO ₂ ) as an active material, 3 parts by weight of acetylene black as a conductive material, 7 parts by weight of polyvinylidene fluoride as a binder, and an appropriate amount of carboxymethyl cellulose aqueous solution as a dispersion medium were prepared. Was mixed to prepare a paste composed of the second electrode mixture. Then, the paste was applied to the entire surface except for the central part of each vapor-deposited film. As a result, two second electrode mixture layers each having a size of 31 mm × 45 mm were formed on each deposited film. Between the two second electrode mixture layers, an exposed portion of a vapor-deposited Al film having no mixture was left in a groove shape having a width of 2 mm. Thereafter, the coating film of the paste was dried, and the dried coating film was rolled with a roller until the thickness became 70 μm.

  A portion of the peripheral portion of the second electrode mixture layer opposite to the portion adjacent to the exposed portion of the deposited film was coated with polyvinylidene fluoride having a width of 0.3 mm as an insulating material. In this way, an aggregate of the second electrodes having the second electrode mixture layers of 6 rows and 6 columns on both surfaces was obtained.

  On the other hand, a second electrode having a second electrode mixture layer only on one side was produced in the same manner as described above, except that the conductive layer, the second electrode mixture layer and the insulating material were not provided on the other side.

(C) Preparation of Electrode Group Two sets of first electrodes having first electrode mixture layers on both surfaces and one assembly of second electrodes having second electrode mixture layers on both surfaces are provided. It was sandwiched via a separator. At this time, the first electrode mixture layer and the second electrode mixture layer face each other, and the exposed portion of the vapor-deposited film and the polyvinylidene fluoride on the first electrode correspond to the polyvinylidene fluoride and the polyvinylidene fluoride on the second electrode, respectively. The bipolar plates were arranged so as to face the exposed portions of the deposited film. Then, on both outermost surfaces, a pair of second electrodes having a second electrode mixture layer only on one side were arranged, the inner electrode was sandwiched by these, and the whole was pressed. As a result, an aggregate composed of a plurality of electrode plate stacks was obtained.

  Next, the cutting position is set to correspond to the center of the exposed portion of the deposited film on the first electrode and the center of the exposed portion of the deposited film on the second electrode. Divided. As a result, as many as 36 electrode plate stacks could be obtained at one time by a series of coating and laminating steps.

  Copper fine particles in a semi-molten state were sprayed on the side surfaces of the first current collector sheet where the exposed portions of the copper vapor-deposited film and the PET resin portions of the second current collector sheet were alternately arranged. As a result, a copper film having a thickness of 0.5 mm was formed on the side surface. At this time, the exposed portion of the copper vapor deposition film had penetrated into the copper film to a depth of 0.2 mm. This copper film can be used as a negative electrode terminal as it is.

  Next, aluminum particles in a semi-molten state were sprayed onto the side surfaces of the second current collector sheet where the exposed portions of the deposited Al film and the PET resin portions of the first current collector sheet were alternately arranged. As a result, an aluminum film having a thickness of 0.5 mm was formed on the side surface. At this time, the exposed portion of the deposited Al film had penetrated into the aluminum film to a depth of 0.2 mm. This aluminum film can be used as it is as a positive electrode terminal.

Lead wires were respectively connected to the copper film and the aluminum film of the electrode group thus obtained, and a charge / discharge test was performed using an external charge / discharge device. The electrolyte used here was prepared by dissolving LiPF ₆ at a concentration of 1 mol / L in a mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) mixed at a volume ratio of 30:70.

[Evaluation]
The charge and discharge were performed in a 20 ° C. atmosphere.
Charging and discharging were performed in a current mode of ^2.5 mA / cm ² with respect to the electrode area, respectively. The charge termination voltage was set to 4.2V. The discharge end voltage was 3.0 V. The electric capacity obtained under the above conditions was 900 mAh. Further, even when the lithium ion secondary battery of Example 1 was dropped and subjected to mechanical shock, no abnormality such as a voltage drop due to an internal short circuit was found.

  As a comparison, a negative electrode was manufactured using a core material made of a conventionally used copper foil, and a positive electrode was manufactured using a core material made of an aluminum foil. Was 1.2 times that of the lithium ion secondary battery of Example 1. From this, it has been clarified that according to the present invention, the energy density per capacity of the electrochemical element can be increased as compared with the related art.

  The electrochemical device of the present invention is suitable as a power source for devices such as a mobile phone, a personal digital assistant, a camcorder, a personal computer, a PDA, a portable audio device, an electric vehicle, and a power source for road leveling.

It is a longitudinal section of the lamination type electrode group concerning the present invention. It is a conceptual diagram which shows the cut part of the assembly which consists of a 1st electrode, and the assembly which consists of a 2nd electrode. It is a conceptual diagram which shows the cut part of the assembly which consists of another 1st electrode, and the assembly which consists of another 2nd electrode. It is a longitudinal section conceptual diagram of a winding type electrode group concerning the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Electrode group 11a, b Resin sheet 11x, y Resin sheet end 12a, b Conductive layer 12x, y Conductive layer end 13a First current collector sheet 13b Second current collector sheet 14a First electrode mixture Layer 14b Second electrode mixture layer 15a First electrode 15b, b 'Second electrode 16 Separator 17a First terminal 17b Second terminal 18a First insulating material portion 18b Second insulating material portion 21a, b Resin sheet 22a First electrode Mixture layer 22b Second electrode mixture layer 23a, b Exposed portion of conductive layer 24a Connection portion to first terminal 24b Connection portion to second terminal 25a, b Cut portion 31a, b corresponding to exposed portion of resin sheet Resin sheet 32a Strip-shaped first electrode mixture layer 32b Strip-shaped second electrode mixture layer 33a, b Exposed portion of conductive layer 34a Connection portion with first terminal 34b Connection portion with second terminal 35a, b Resin Cutting unit 40 the separator 41 first terminal 42 second terminal corresponding to the exposed portion of the over bets

Claims (12)

An electrochemical device having (a) at least one first electrode, (b) at least one second electrode, and (c) an electrode group including a separator interposed between the first electrode and the second electrode. hand,
The first electrode (a) includes a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer carried on the first current collector sheet,
The second electrode (b) is an electrochemical element comprising a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet.   A conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group, and a conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode plate group. 2. The electrochemical device according to claim 1, wherein an insulating portion of the first current collector sheet is disposed on the second side surface, and an insulating portion of the second current collector sheet is disposed on the first side surface. 3. element.   The insulating portion of the first current collector sheet and the insulating portion of the second current collector sheet are arranged on a side surface of the electrode plate group other than the first side surface and the second side surface. Electrochemical element.   The said electrode group has a side which the insulating part of the said 1st current collector sheet and / or the insulating part of the said 2nd current collector sheet | seat is arrange | positioned other than the said 1st side surface and the said 2nd side surface. Item 3. An electrochemical device according to Item 2.   The electrochemical device according to claim 2, wherein the first side surface and the second side surface are located on opposite sides of the electrode group.   A first insulating material portion for insulating the first terminal and the second electrode is provided on the first side surface, and the second terminal, the first electrode, and the second side surface are provided on the second side surface. The electrochemical device according to claim 2, further comprising a second insulating material portion for insulating the element. An electrochemical device having an electrode group in which a first electrode and a second electrode are wound with a separator interposed therebetween,
The first electrode includes a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer supported on the first current collector sheet,
The second electrode includes a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet,
A conductive portion of the first current collector sheet is connected to a first terminal on a first bottom surface of the electrode plate group;
A conductive portion of the second current collector sheet is connected to a second terminal on a second bottom surface of the electrode plate group;
An insulating portion of the first current collector sheet is disposed on the second bottom surface;
An electrochemical device wherein an insulating portion of the second current collector sheet is disposed on the first bottom surface. An electrochemical device having an electrode group in which a first electrode and a second electrode are wound with a separator interposed therebetween,
The first electrode includes a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer supported on the first current collector sheet,
The second electrode includes a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet,
A conductive portion of the first current collector sheet is connected to a first terminal on a first bottom surface of the electrode plate group;
A conductive portion of the second current collector sheet is connected to a second terminal on a second bottom surface of the electrode plate group;
An insulating portion of the first current collector sheet is disposed on the second bottom surface;
An insulating portion of the second current collector sheet is disposed on the first bottom surface;
A first insulating material portion for insulating the first terminal and the second electrode from each other on the first bottom surface;
An electrochemical device, wherein a second insulating material portion for insulating the second terminal and the first electrode is provided on the second bottom surface. An electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween,
The plurality of first electrodes include a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer supported on the first current collector sheet,
The plurality of second electrodes each include a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet,
A conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group;
A conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode plate group;
An insulating portion of the first current collector sheet is disposed on the second side surface;
An electrochemical device wherein an insulating portion of the second current collector sheet is disposed on the first side surface. An electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween,
The plurality of first electrodes include a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer supported on the first current collector sheet,
The plurality of second electrodes each include a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet,
A conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group;
A conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode plate group;
An insulating portion of the first current collector sheet is disposed on the second side surface;
An insulating portion of the second current collector sheet is disposed on the first side surface;
A first insulating material portion for insulating the first terminal and the second electrode from each other on the first side surface;
An electrochemical device, wherein a second insulating material portion for insulating the second terminal and the first electrode is provided on the second side surface. An electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween,
The plurality of first electrodes include a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer supported on the first current collector sheet,
The plurality of second electrodes each include a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet,
A conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group;
A conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode plate group;
Insulating portions of the first current collector sheet are arranged on all side surfaces other than the first side surface of the electrode plate group,
An electrochemical device in which insulating portions of the second current collector sheet are arranged on all side surfaces of the electrode plate group except the second side surface. An electrochemical device having an electrode group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked with a separator interposed therebetween,
The plurality of first electrodes include a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer supported on the first current collector sheet,
The plurality of second electrodes each include a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried on the second current collector sheet,
A conductive portion of the first current collector sheet is connected to a first terminal on a first side surface of the electrode plate group;
A conductive portion of the second current collector sheet is connected to a second terminal on a second side surface of the electrode plate group;
Insulating portions of the first current collector sheet are arranged on all side surfaces other than the first side surface of the electrode plate group,
Insulating portions of the second current collector sheet are disposed on all side surfaces except the second side surface of the electrode plate group,
A first insulating material portion for insulating the first terminal and the second electrode from each other on the first side surface;
An electrochemical device, wherein a second insulating material portion for insulating the second terminal and the first electrode is provided on the second side surface.

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