JP4249527B2 - Method for producing electrochemical element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrochemical device, and more particularly to an improvement in an electrode plate group of a secondary battery having a high energy density such as a lithium ion secondary battery.
[0002]
[Prior art]
As electronic and electric devices become smaller and lighter, there is an increasing demand for smaller and lighter secondary batteries. On the other hand, the current secondary battery has a complicated internal structure, and there is a limit in improving the electric capacity of the product per fixed volume. In addition, a complicated structure hinders improvement of battery reliability. For example, a current collecting tab or current lead connected to the electrode may prevent a uniform electrode reaction at the electrode surface. In the unlikely event that a metal burr larger than usual occurs on the cut surface of the lead, there is a concern about the occurrence of an internal short circuit.
[0003]
The secondary battery has an electrode plate group including a positive electrode, a negative electrode, and a separator, and the electrode plate group includes a stacked type and a wound type. The laminated electrode plate group is obtained by alternately laminating positive electrodes and negative electrodes via separators. The wound electrode plate group is obtained by winding a long positive electrode and a negative electrode through a separator. These electrode plate groups usually have side surfaces in which the ends of the positive electrode and the negative electrode are arranged flush with each other. In order to take out electricity without causing a short circuit from such a side, a current collecting tab and a current collecting lead are required.
[0004]
Therefore, from the viewpoint of simplifying the internal structure of the battery, the positive electrode is protruded from one of the side surfaces of the electrode plate group, the negative electrode is protruded from the side surface opposite to the side surface, and the current collecting tab or current collecting lead is interposed Instead, it has been proposed to take electricity directly from each side. For example, in a battery having a stacked electrode plate group, a technique has been proposed in which a protruded electrode plate of the same polarity is integrally joined using a predetermined metal member (see, for example, Patent Document 1). In addition, in a battery having a wound-type electrode plate group, a technique has been proposed in which a protruding core member of the same polarity and a plate-like current collector plate are joined (for example, see Patent Document 2). .
[0005]
[Patent Document 1]
JP 2001-126707 A
[Patent Document 2]
JP 2000-294222 A
[0006]
[Problems to be solved by the invention]
However, when the positive electrode is protruded from one of the side surfaces of the electrode plate group and the negative electrode is protruded from the side surface opposite to the side surface, the electrode plate group must be produced one by one. The process becomes complicated. That is, there is a problem that a plurality of electrode plate groups cannot be manufactured simultaneously.
[0007]
[Means for Solving the Problems]
The present invention has been made in view of the above situation. According to the present invention, a plurality of electrochemical elements having a simple structure, high reliability, and high electric capacity can be efficiently manufactured at the same time.
[0008]
  That is, the present invention provides (a) sheet-likeFirstBoth insulating base materialsSide tablesurfaceOf the first electrode made of a matrix pattern or a strip pattern at positions facing each other across the first insulating substrate.First current collector with conductive layerBodyObtaining processWhen,( a ' ) A second electrode conductive layer made of a matrix pattern or a strip pattern is provided on the both side surfaces of the sheet-like second insulating base material so as to face each other across the second insulating base material. Obtaining a current collector;(B)eachSaidFor first electrodeConductive layersurfaceInLeave,Of the conductive layer for the first electrodeWhile corresponding to the patternA first exposed portion that exposes the first electrode conductive layer along any one of a row direction and a column direction of the matrix pattern and a length direction of the strip pattern. The pattern of the agent layerForming the first electrodeGroupObtaining processWhen,( b ' ) On the surface of each second electrode conductive layer, it corresponds to the pattern of the second electrode conductive layer, and is along any one of the row direction and column direction of the matrix pattern and the length direction of the strip pattern. Forming a second electrode mixture layer pattern by providing a second exposed portion where the second electrode conductive layer is exposed, and obtaining a second electrode group;(C)The first exposed portion in the first electrode group and a second gap portion in which the second electrode conductive layer is not formed in the second electrode group are opposed to each other, and the second in the second electrode group. The separator is sandwiched between the exposed portion and the first gap portion where the first electrode conductive layer is not formed in the first electrode group.The first electrode groupWhenThe second electrode groupAndLamination and obtaining a laminateWhen, (D)A first edge is formed along the first exposed portion of the first electrode group and the second gap portion of the second electrode group; and the first gap portion of the first electrode group; and A second edge is formed along the second exposed portion of the second electrode group.The laminateTurn offTo obtain a plurality of laminated electrode plate groups by cuttingWhen,including,A method for manufacturing an electrochemical device is provided.
[0010]
  Moreover, the method for producing an electrochemical device according to the present invention comprises the step (b).And said process ( b ' )And before step (c)Leave,at least,SaidA surface of the second gap portion of the second electrode plate group at the first edge and a surface of the first gap portion of the first electrode plate group at the second edge, respectively.It is effective to include a step of forming the insulating material portion.
[0011]
  Furthermore, the method for producing an electrochemical device according to the present invention includes:An end on the first end side and an end on the second end side in the laminated electrode plate group,It is effective to include a step of coating with metal to form the first terminal and the second terminal.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention provides (a) sheet-likeFirstBoth insulating base materialsSide tablesurfaceOf the first electrode made of a matrix pattern or a strip pattern at positions facing each other across the first insulating substrate.First current collector with conductive layerBodyObtaining processWhen,( a ' ) A second electrode conductive layer made of a matrix pattern or a strip pattern is provided on the both side surfaces of the sheet-like second insulating base material so as to face each other across the second insulating base material. Obtaining a current collector;(B)eachSaidFor first electrodeConductive layersurfaceInOf the conductive layer for the first electrodeWhile corresponding to the patternA first exposed portion that exposes the first electrode conductive layer along any one of a row direction and a column direction of the matrix pattern and a length direction of the strip pattern. The pattern of the agent layerForming the first electrodeGroupObtaining processWhen,( b ' ) On the surface of each second electrode conductive layer, it corresponds to the pattern of the second electrode conductive layer, and is along any one of the row direction and column direction of the matrix pattern and the length direction of the strip pattern. Forming a second electrode mixture layer pattern so as to provide a second exposed portion where the second electrode conductive layer is exposed, and obtaining a second electrode group;, (C)The first exposed portion in the first electrode group and a second gap portion in which the second electrode conductive layer is not formed in the second electrode group are opposed to each other, and the second in the second electrode group. The separator is sandwiched between the exposed portion and the first gap portion where the first electrode conductive layer is not formed in the first electrode group.The first electrode groupWhenThe second electrode groupAndLamination and obtaining a laminateWhen,(D)A first edge is formed along the first exposed portion of the first electrode group and the second gap portion of the second electrode group; and the first gap portion of the first electrode group; and A second edge is formed along the second exposed portion of the second electrode group.The laminateTurn offTo obtain a plurality of laminated electrode plate groups by cuttingWhen,The manufacturing method of the electrochemical element containing this.
[0013]
The main steps (a) to (d) of the method for producing an electrochemical device according to the present invention will be described in the order of steps. Further, other steps will be described as appropriate. Other steps can be appropriately selected and combined by those skilled in the art depending on the structure and application of the electrochemical device obtained by the production method according to the present invention. Further, the present invention is not limited to these.
[0014]
Step (a)and( a ' )
  First, step (a)and( a ' ), A conductive layer is provided in a predetermined pattern on both surfaces of the sheet-like insulating substrate to obtain a first current collector and a second current collector.
  As shown in FIG. 1, a resin sheet 21a that is a sheet-like insulating substrate having a size capable of providing a desired number of current collector sheets is prepared, and a plurality of predetermined sheets are provided at the same position on both surfaces of the resin sheet 21a. A patterned conductive layer is provided. Here, a matrix-like pattern will be described as the predetermined pattern.
[0015]
  For example, conductive layers having 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 by a method of coating a resin sheet with a matrix-like mask and depositing a metal on the resin sheet exposed from the mask.
  The resin sheet 21a has a size equivalent to two electrodes.For first electrodeA plurality of conductive layers 26a are formed. That is, when obtaining 2n electrodes, n conductive layers are formed on one side of the resin sheet. In this way, the first current collector is obtained.
[0016]
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 side of the resin sheet.
The second current collector may be manufactured in the same manner. That is, as shown in FIG. 1, a plurality of conductive layers having a predetermined shape pattern are provided at the same position on both surfaces of a resin sheet 21b having a size capable of providing a desired number of current collector sheets, and the second current collector is provided. obtain.
[0017]
Here, the thickness of the resin sheet is preferably, for example, 0.5 to 500 μm. Moreover, it is preferable that the thickness of a conductive layer is 0.01-100 micrometers. Although the thickness of a 1st electrode mixture layer is not specifically limited, For example, it is preferable that it is 1-1000 micrometers.
[0018]
Examples of the resin sheet include olefin polymers such as polyethylene, polypropylene and polymethylpentene, ester polymers such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate and polyarylate, and thioethers 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 singly or may be a copolymer, polymer alloy, polymer blend or the like combining two or more.
[0019]
Note that a normal resin sheet having a flat surface may be used, and a perforated body, a lath body, a porous body, a net, a foamed body, a woven fabric, a non-woven fabric, or the like may be used. Moreover, the resin sheet which has an unevenness | corrugation on the surface can also be used.
[0020]
As the conductive layer, an electronic conductor that does not cause a chemical change in the constructed battery can be used without any particular limitation. In the case where the first electrode is a positive electrode, for example, stainless steel, aluminum, aluminum alloy, titanium, carbon and the like can be used, and aluminum, aluminum alloy and the like are particularly preferable. Further, when the first electrode is a negative electrode, for example, stainless steel, nickel, copper, copper alloy, titanium, and the like can be used, and copper, copper alloy, and the like are particularly preferable.
[0021]
The method for forming the conductive layer is preferably obtained by, for example, a method in which a resin sheet is covered with a matrix mask and a metal is deposited on the resin sheet exposed from the mask. Note that the mask in this case is a sheet-like mask having openings in a matrix, or oil applied in a matrix on a resin sheet for the purpose of inhibiting the deposition metal deposition. Other methods include printing ink in a matrix on a resin sheet, depositing the metal, and then cleaning and removing the ink and the deposited metal on the ink, after depositing the metal on the resin sheet, laser, etc. However, the method is not particularly limited to these methods.
[0022]
Step (b)and( b ' )
  Next, on the conductive layer, a plurality of first electrode mixture layers and second electrode mixture layers are formed corresponding to the pattern and provided with gaps, and the first electrode group and the second electrode Get a group.
  As shown in the upper side of FIG.For first electrodeConductive layer26aofsurfaceIn addition, two first electrode mixture layers 22a are formed. There is no mixture as a gap between the two first electrode mixture layersFor first electrodeConductive layerFirstThe exposed part 23a is left.
[0023]
The first electrode mixture layer is formed by applying a paste made of the first electrode mixture to the entire surface except for the central portion of the conductive layer. The coating method is not particularly limited, but it is preferable to employ screen printing, pattern coating, or the like. At this time, the exposed portion of the conductive layer to which the paste made of the mixture was not applied becomes the connecting portion 24a with the first terminal after the electrode plate group is configured.
[0024]
In FIG. 2, an electrode mixture layer of 3 rows and 3 columns is drawn, but usually more conductive layers and electrode mixture layers are formed on a larger current collector sheet.
The first electrode mixture is prepared by mixing the active material, conductive material, binder, and the like of the first electrode with a dispersion medium. Thereafter, the coating film of the paste is dried, and the dried coating film is rolled with a roller to increase the mixture density.
[0025]
Here, when the first electrode is a 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 oxide include Li_xCoO_z, Li_xNiO_z, Li_xMnO_z, Li_xCo_yNi_1-yO_z, Li_xCo_fV_1-fO_z, Li_xNi_1-yM_yO_z(M = Ti, V, Mn, Fe), Li_xCo_aNi_bM_cO_z(M = Ti, Mn, Al, Mg, Fe, Zr), Li_xMn₂O_Four, Li_xMn_{2 (1-y)}M_2yO_Four(M = Na, Mg, Sc, Y, Fe, Co, Ni, Ti, Zr, Cu, Zn, Al, Pb, Sb). However, the x value varies in the range of 0 ≦ x ≦ 1.2 depending on the charge / discharge 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, 0 ≦ c <1 is there. These may be used alone or in combination of two or more.
[0026]
When the first electrode group is used for the negative electrode of a lithium ion secondary battery, examples of the active material include lithium, lithium alloys, intermetallic compounds, carbon materials, organic compounds and inorganic compounds capable of inserting and extracting lithium ions, and metals. Complexes, organic polymer compounds and the like can be preferably used. These may be used alone or in combination of two or more.
[0027]
Examples of carbon materials include coke, pyrolytic carbon, natural graphite, artificial graphite, mesocarbon microbeads, graphitized mesophase microspheres, vapor-grown carbon, glassy carbon, carbon fibers (polyacrylonitrile-based, pitch-based, cellulose-based, Vapor phase growth system), amorphous carbon, and organic compound fired body. Of these, natural graphite and artificial graphite are particularly preferable.
[0028]
As the conductive material, for example, carbon black such as acetylene black, graphite or the like is used. As the binder, for example, a fluororesin such as polyvinylidene fluoride and polytetrafluoroethylene, an acrylic resin, a styrene butadiene rubber, an ethylene propylene terpolymer, and the like can be used.
[0029]
  Here, the step (b)and( b ' )After step (c) described laterLeave,at least,SaidA surface of the second gap portion of the second electrode plate group at the first edge and a surface of the first gap portion of the first electrode plate group at the second edge, respectively.It is preferable to perform the process of forming an insulating material part.
  That is, when the electrode plate group is configured, the second current collector sheetFor the second electrodeConductive layerSecondAn insulating material is applied along the periphery of the first electrode mixture layer that will be adjacent to the exposed portion. Here too, it is preferable to perform pattern coating.
[0030]
The other part of the peripheral edge of the first electrode mixture layer may be covered with an insulating material, but the entire exposed part of the conductive layer of the first current collector sheet is not covered. When obtaining the electrode plate group as shown in FIG. 2, an insulating material is applied to at least the side opposite to the exposed portion side of the conductive layer in the peripheral portion of the first electrode mixture layer. Note that the application of the insulating material is not necessarily required and may be performed arbitrarily. The insulating resin applied here forms the first insulating material portion in the electrode plate group.
[0031]
Further, the second electrode group may be formed in the same manner as the first electrode group.
Furthermore, in the laminated body obtained by the process (c) mentioned later, the 2nd electrode mixture layer is provided only in the 1st electrode group which has a 1st electrode mixture layer only in the single side | surface at each both ends of a laminated body, and one side. It is effective to stack the second electrode group having the first electrode mixture layer and the second electrode mixture layer inward. This is because the electrode mixture layer is not exposed in the outermost layer.
[0032]
In this case, although the said electrical power collector may be exposed to the outermost layer of a laminated body, the said insulating base material may be exposed, without providing the said conductive layer. For the second electrode group having the second electrode mixture layer only on one side, the conductive layer, the first electrode mixture layer or the second electrode mixture layer, and the insulating material are not provided on the other side, It can be produced by the same method as described above.
[0033]
Step (c)
  Next, the first electrode group and the second electrode group are,Lamination is performed via a separator to obtain a laminate.
  Step (b)and( b ' )The first electrode group and the second electrode group produced by the above are stacked via a separator. At this time, the first electrode mixture layer 22a included in the first electrode group and the second electrode mixture layer 22b included in the second electrode group are laminated so as to face each other.
[0034]
Further, the bipolar plates are arranged so that the exposed portion 23a of the conductive layer and the insulating material in the first electrode group face the insulating material and the exposed portion 23b of the conductive layer in the second electrode group, respectively. And a pair of 2nd electrode group which has a 2nd electrode mixture layer only on one side is arrange | positioned on both outermost surfaces, an inner side electrode group is clamped by these, and the whole is pressed. As a result, a multilayer body including a plurality of multilayer electrode groups is obtained.
[0035]
For the separator, a woven fabric or a nonwoven fabric made of an olefin polymer such as polyethylene or polypropylene or glass fiber can be used.
A solid electrolyte or gel electrolyte can also be used as a separator.
For the solid electrolyte, for example, polyethylene oxide, polypropylene oxide or the like can be used as the matrix material.
[0036]
Moreover, as a gel electrolyte, what hold | maintained the below-mentioned non-aqueous electrolyte in the matrix which consists of polymer materials can be used, for example. As the polymer material for 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.
[0037]
Step (d)
Then, the laminated body is cut at the gap to obtain a plurality of laminated electrode plate groups.
An assembly composed of a plurality of electrode plate stacks is divided into electrode plate stacks. At this time, the first electrode and the second electrode are cut at the gap along the arrow direction shown in FIG. The cut portions of the current collector sheet corresponding to the gaps that are the exposed portions of the conductive layers are the connection portions 24a and 24b with the terminals, and the cut portions 25a and 25b corresponding to the exposed portions of the resin sheet on the opposite side are the insulating portions. It becomes.
[0038]
In the case of a current collector made of a metal foil that has been generally used from the past, metal burrs generated during cutting become a problem. This is because the metal burrs break through the separator and cause a major short circuit. Therefore, it is important to prevent the occurrence of metal burrs, but it is extremely difficult to cut the metal foil without causing 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, no metal burrs are generated. Therefore, the reliability of the electrochemical device can be greatly improved.
[0039]
  Here, the laminated plate groupIn the aboveFirstThe end on the edge side and the endSecondThe edge on the edge sideThe,RespectivelyIt is preferable to perform the step of covering with metal and forming the first terminal and the second terminal.
  First current collector sheetFor the first electrodeConductive layerFirstExposed part and,A side surface in which 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 metal by spraying molten or semi-molten metal fine particles on the side surface.
[0040]
In the said side surface, since the insulating material is applied to the end surface of the second electrode, 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 surfaces where 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 are also covered with metal in the same manner as described above.
[0041]
When the terminal is a positive electrode terminal, it is preferable to use aluminum powder as the metal fine particles. Moreover, when a terminal turns into a negative electrode terminal, it is preferable to use copper powder as said metal microparticle.
[0042]
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 are respectively used as the first terminal and the second terminal. Function. On the other hand, the side surfaces of the electrode group having no terminals may be left as they are, but it is preferable to cover them with a porous insulating material if possible.
In this way, the electrochemical device according to the present invention can be obtained.
[0043]
FIG. 3 shows a schematic cross-sectional view of the electrochemical element according to the present invention obtained through these steps. The stacked 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 electrode 15a and the second electrode 15b. is doing.
The first electrode 15a is composed of a first current collector sheet 13a and two first electrode mixture layers 14a. The first current collector sheet 13a is a resin sheet 11a and a predetermined shape pattern provided on both surfaces thereof. It is comprised with the conductive layer 12a which has. 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.
[0044]
In FIG. 3, a conductive layer is provided on the entire surface except one end portion 11x of the resin sheet or on the entire surface excluding the end portions 11x and the end portions located on the front and back of the paper surface of FIG. A first electrode mixture layer is provided on the conductive layer. In the first current collector sheet of FIG. 1, the end portion 11x or the end portion 11x of the resin sheet that does not have a conductive layer and the end portion located on the front and back of the paper surface of FIG. 1 function as an insulating portion. The exposed portion of the conductive layer is left at the end portion 12x of the conductive layer located on the opposite side of the end portion 11x.
[0045]
Here, a case where the predetermined pattern in the step (a) has a strip shape arranged in parallel will be described. In this case, an assembly of electrode plate groups can be obtained by producing a plurality of first electrode groups and second electrode groups as shown in FIG.
[0046]
When obtaining such a first electrode group, a plurality of rows of strip-like conductive layers are formed at the same position on both surfaces of a 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 strip-shaped mask and depositing metal on the resin sheet portion exposed from the mask. Also here, 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 side of the resin sheet.
[0047]
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 as a gap between the two strip-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 excluding the central portion of the conductive layer. The coating method is the same as that described above. At this time, the exposed portion 33a of the conductive layer to which the paste is not applied becomes a connection portion 34a with the first terminal.
[0048]
Further, when obtaining the second electrode group, a plurality of rows of strip-like conductive layers are provided at the same positions on both surfaces of the resin sheet 31b having a size capable of providing a desired number of current collector sheets, and on each conductive layer, Two strip-shaped second electrode mixture layers 32b are formed. An exposed portion 33b of the conductive layer having no mixture is left between the two strip-shaped second electrode mixture layers. At this time, the exposed portion of the conductive layer to which the paste made of the mixture was not applied becomes the connection portion 34b with the second terminal after the electrode plate group is configured.
[0049]
When the laminated body, which is an assembly of such electrode plate groups, is divided into individual laminated electrode plate groups along the direction of the arrow shown in FIG. 4, the current collector sheet corresponding to the exposed portion of the conductive layer is divided. The cut portions become the connection portions 34a and 34b with the terminals, 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 section of the mixture is exposed at the other cut portions. become. In this case, it is preferable to seal the side surface of the electrode plate group where the cross section of the mixture is exposed with a porous insulating material.
[0050]
The laminated electrode plate group obtained as described above is housed together with a predetermined electrolyte in a case having a predetermined shape as necessary. As the case, for example, a stainless steel plate, an aluminum plate or the like processed into a predetermined shape, an aluminum foil (aluminum laminate sheet) having a resin film on both sides, a resin case, or the like is used.
In the case where the electrochemical element is, for example, a lithium ion secondary battery, an electrolytic solution in which a lithium salt is dissolved in a nonaqueous solvent is used. The lithium salt concentration in the electrolytic solution is preferably 0.5 to 1.5 mol / L, for example.
[0051]
Nonaqueous solvents include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, non-dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethyl propyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate, and the like. Cyclic carbonate, aliphatic formate such as methyl formate, methyl acetate, methyl propionate, ethyl propionate, γ-lactone such as γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane, 1,2-di 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 plural kinds. 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 preferred.
[0052]
LiPF includes LiPF₆, LiBF_FourLiClO_FourLiAlCl_Four, LiSbF₆, LiSCN, LiCl, LiCF_ThreeSO_Three, LiCF_ThreeCO₂, LiAsF₆, LiN (CF_ThreeSO₂)₂, Li₂B_TenCl_Ten, LiN (C₂F_FiveSO₂)₂, LiPF_Three(CF_Three)_Three, LiPF_Three(C₂F_Five)_ThreeEtc. can be used. These may be used alone or in combination of two or more, but at least LiPF6 is preferably used.
[0053]
According to the above manufacturing method, for example, an electrode plate group having an arbitrary size can be efficiently manufactured as long as it is in the range of 1 to 300 mm in length, 1 to 300 mm in width, and 0.01 to 20 mm in thickness. it can.
The electrochemical device according to the present invention obtained as described above comprises at least one first electrode, (b) at least one second electrode, and a separator interposed between the first electrode and the second electrode. An electrochemical device having an electrode plate group, wherein the first electrode comprises a first current collector sheet having a conductive portion and an insulating portion, and at least one first electrode mixture layer carried thereon, The second electrode (b) includes a second current collector sheet having a conductive portion and an insulating portion, and at least one second electrode mixture layer carried thereon.
[0054]
The conductive portion of the first current collector sheet is connected to the first terminal on the first side surface of the electrode plate group, and the conductive portion of the second current collector sheet is the second terminal on the second side surface of the electrode plate group. It is preferable that the insulating part of the first current collector sheet is disposed on the second side surface, and the insulating part of the second current collector sheet is disposed on the first side surface.
[0055]
The insulating part of the first current collector sheet and the insulating part 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 plate 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.
The first side surface and the second side surface are preferably located on opposite sides of the electrode plate group.
A first insulating material part for insulating the first terminal and the second electrode may be provided between the first terminal and the first side surface. In addition, a second insulating material portion for insulating the second terminal and the first electrode can be provided between the second terminal and the second side surface.
[0056]
In other words, the electrochemical device according to the present invention is an electrochemical device having an electrode plate group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked via separators, the plurality of first electrodes Each of the electrodes 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, and the plurality of second electrodes include a conductive portion and an insulating portion, respectively. A second current collector sheet having at least one second electrode mixture layer carried thereon, and a conductive portion of the first current collector sheet is a first terminal on a first side surface of the electrode plate group. And the conductive portion of the second 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 disposed on the second side surface, An insulating part of the second current collector sheet is disposed on the first side surface. That.
[0057]
The electrochemical element according to the present invention is an electrochemical element having an electrode plate group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked via separators, wherein the plurality of first electrodes Comprises a first current collector sheet having a conductive portion and an insulating portion, respectively, and at least one first electrode mixture layer carried thereon, and the plurality of second electrodes include a conductive portion and an insulating portion, respectively. A second current collector sheet having at least one second electrode mixture layer carried thereon, and 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. Connected, the conductive portion of the second current collector sheet is connected to the second terminal on the second side surface of the electrode plate group, the insulating portion of the first current collector sheet is disposed on the second side surface, An insulating part of the second current collector sheet is disposed on the first side surface; A first insulating material part is provided between the terminal and the first side surface to insulate the first terminal and the second electrode, and between the second terminal and the second side surface. A second insulating material portion for insulating the second terminal and the first electrode is provided.
[0058]
The electrochemical device according to the present invention is also an electrochemical device having an electrode plate group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked via separators, wherein the plurality of first electrodes Comprises a first current collector sheet having a conductive portion and an insulating portion, respectively, and at least one first electrode mixture layer carried thereon, and the plurality of second electrodes include a conductive portion and an insulating portion, respectively. A second current collector sheet having at least one second electrode mixture layer carried thereon, and 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. Connected, 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, and an insulating portion of the first current collector sheet is the first side surface of the electrode plate group. Arranged on all side surfaces except for the insulating part of the second current collector sheet It is arranged at all sides except for the second side plate group.
[0059]
Furthermore, the electrochemical device according to the present invention is an electrochemical device having an electrode plate group in which a plurality of first electrodes and a plurality of second electrodes are alternately stacked via separators, the plurality of first electrodes. One electrode includes a first current collector sheet having a conductive portion and an insulating portion, respectively, and at least one first electrode mixture layer carried thereon, and the plurality of second electrodes are insulated from the conductive portion, respectively. A second current collector sheet having at least one portion, and at least one second electrode mixture layer carried thereon, wherein the conductive portion of the first current collector sheet is first on the first side surface of the electrode plate group. Connected to the terminal, the conductive portion of the second 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 the first electrode of the electrode plate group. Arranged on all sides except one side, insulation of the second current collector sheet Is arranged on all side surfaces other than the second side surface of the electrode plate group, and a first insulation for insulating the first terminal and the second electrode between the first terminal and the first side surface. A material part is provided, and a second insulating material part for insulating the second terminal and the first electrode is provided between the second terminal and the second side surface.
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
[0060]
【Example】
"Example"
In this example, a stacked lithium ion secondary battery was manufactured in the following manner.
Step (a)
First, a conductive layer was provided on both surfaces of a sheet-like insulating substrate based on a predetermined pattern to obtain a first current collector and a second current collector.
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, using a mask having a matrix-like opening, a plurality of rectangular (65 mm × 46 mm) copper deposited films arranged in 3 rows and 6 columns are formed at the same positions on both sides of the PET sheet. I got an electric body. The thickness of the copper vapor deposition film was 0.1 μm.
Next, a PET sheet having a width of 198 mm, a length of 282 mm, and a thickness of 7 μm was prepared. Next, using a mask having a matrix-like opening, a plurality of rectangular (64 mm × 45 mm) aluminum deposited films arranged in 3 rows and 6 columns are formed at the same positions on both sides of the PET sheet. I got an electric body. The thickness of the Al vapor deposition film was 0.1 μm.
[0061]
Step (b)
Next, a plurality of first electrode mixture layers and second electrode mixture layers are formed on the conductive layer with gaps corresponding to the patterns, respectively, and the first electrode group and the second electrode group Got.
By mixing 100 parts by weight of active material spheroidal graphite (graphitized mesophase spherules), 3 parts by weight of styrene butadiene rubber as a binder, and an appropriate amount of carboxymethyl cellulose aqueous solution as a dispersion medium, the first electrode mixture A paste consisting of was prepared.
And the paste was applied to the whole surface except the center part of each vapor deposition film. As a result, two 32 mm × 46 mm first electrode mixture layers were formed on each deposited film. Between the two 1st electrode mixture layers, the exposed part of the copper vapor deposition film which does not have a mixture was left in the groove | channel shape of width 1mm. 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, polyvinylidene fluoride having a width of 0.3 mm was applied as an insulating material to a portion on the side opposite to the portion adjacent to the exposed portion of the deposited film in the peripheral portion of the first electrode mixture layer. In this way, the 1st electrode group which has the 1st electrode mixture layer of 6 rows 6 columns on both surfaces was obtained.
[0062]
Next, lithium cobaltate (LiCoO) as an active material₂) By mixing 100 parts by weight, 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 an aqueous solution of carboxymethylcellulose as a dispersion medium, A paste was prepared.
And the paste was applied to the whole surface except the center part of each vapor deposition film. As a result, two 31 mm × 45 mm second electrode mixture layers were formed on each deposited film. Between the two 2nd electrode mixture layers, the exposed part of the vapor deposition film of Al which does not have a mixture was left in the groove shape of width 2mm. 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, polyvinylidene fluoride having a width of 0.3 mm was applied as an insulating material to a portion on the side opposite to the portion adjacent to the exposed portion of the deposited film in the peripheral portion of the second electrode mixture layer. Thus, a second electrode group having 6 rows and 6 columns of the second electrode mixture layer on both surfaces was obtained.
On the other hand, the second electrode having the 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.
[0063]
Step (c)
Next, the first electrode group and the second electrode group were laminated via a separator to obtain a laminated body.
Two first electrode groups having a first electrode mixture layer on both surfaces and one second electrode group having a second electrode mixture layer on both surfaces were sandwiched via a separator. At this time, so that the first electrode mixture layer and the second electrode mixture layer face each other, and the exposed portion of the vapor deposition film and the polyvinylidene fluoride in the first electrode group are respectively polyfluorinated in the second electrode group. Bipolar plates were placed so as to face vinylidene and the exposed portions of the deposited film. And a pair of 2nd electrode which has a 2nd electrode mixture layer only on one side was distribute | arranged to both outermost surfaces, the inner side electrode was clamped by these, and the whole was pressed. As a result, a multilayer body including a plurality of multilayer electrode groups was obtained.
[0064]
Step (d)
The laminated body was cut at the gap to obtain a plurality of laminated electrode plate groups.
The assembly made up of a plurality of electrode plate stacks was divided for each electrode plate stack so that the cutting position corresponded to the center of the exposed portion of the vapor deposition film in the first electrode and the center of the exposed portion of the vapor deposition film in the second electrode. As a result, as many as 36 electrode plate stacks could be obtained at a time through a series of coating and laminating processes.
Thereafter, semi-molten copper fine particles were sprayed on the side surface where the exposed portions of the copper vapor deposition film of the first current collector sheet 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-deposited film bite 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.
[0065]
Next, semi-molten aluminum fine particles were sprayed on the side surfaces where the exposed portions of the Al vapor deposition film of the second current collector sheet 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 Al vapor deposition film bite into the aluminum film to a depth of 0.2 mm. This aluminum film can be used as a positive electrode terminal as it is.
Lead wires were respectively connected to the copper film and the aluminum film of the laminated electrode plate group thus obtained, and a charge / discharge test was performed using an external charge / discharge device.
The electrolyte used here was LiPF in a mixed solvent in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a volume ratio of 30:70.₆Was dissolved at a concentration of 1 mol / L.
[0066]
[Evaluation]
Charging / discharging was performed in a 20 ° C. atmosphere.
Charging and discharging are each 2.5 mA / cm with respect to the electrode area.²The current mode was performed. The end-of-charge voltage was 4.2V. The final discharge voltage was 3.0V. The electric capacity obtained under the above conditions was 900 mAh.
As a comparison, when a negative electrode was produced using a core material made of copper foil, which was conventionally used, and a positive electrode was made using a core material made of aluminum foil, in order to obtain a battery having the same capacity The capacity of the battery was 1.2 times that of the lithium ion secondary battery of the example. From this, it became clear that according to the present invention, the energy density per capacity of the electrochemical device can be increased as compared with the conventional case.
Further, even when the lithium ion secondary battery of the example was dropped and given a mechanical impact, no abnormality such as a voltage drop due to an internal short circuit was observed.
[0067]
【The invention's effect】
As described above, according to the present invention, the structure of the positive electrode terminal and the negative electrode terminal is simple, and there is no need to use a current collecting tab or a current collecting lead. An electrochemical element can be provided. And according to this invention, a several electrochemical element can be manufactured efficiently simultaneously. By using a non-aqueous electrolyte secondary battery including such an electrochemical element, a highly reliable mobile phone, portable information terminal device, camcorder, personal computer, PDA, portable acoustic device, electric vehicle, power source for load leveling Etc. can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a state in which a conductive layer is provided on an insulating substrate based on a predetermined pattern in a manufacturing method according to the present invention.
FIG. 2 is a view for explaining a state in which a mixture layer is provided on a conductive layer of a current collector in the manufacturing method according to the present invention.
FIG. 3 is a schematic cross-sectional view of a stacked electrode group which is an electrochemical element obtained by the manufacturing method according to the present invention.
FIG. 4 is another view for explaining a state in which a mixture layer is provided on the conductive layer of the current collector in the manufacturing method according to the present invention.
[Explanation of symbols]
10 Laminated plate group
11a, b Resin sheet
11x, y End of resin sheet
12a, b Conductive layer
12x, y End of conductive layer
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 1st terminal
17b Second terminal
18a First insulating material part
18b Second insulating material part
21a, b Resin sheet
22a First electrode mixture layer
22b Second electrode mixture layer
23a, b Exposed portion of conductive layer
24a Connection with first terminal
24b Connection with second terminal
25a, b Cutting portion corresponding to the exposed portion of the resin sheet
31a, b Resin sheet
32a Band-shaped first electrode mixture layer
32b Band-shaped second electrode mixture layer
33a, b Exposed portion of conductive layer
34a Connection with first terminal
34b Connection with second terminal
35a, b Cutting portion corresponding to the exposed portion of the resin sheet
40 separator

Claims (3)

(A), of the two side table surface of the first insulating base sheet, at a position facing each other across said first insulating substrate, a first electrode conductive layer made of a matrix pattern or a strip pattern obtaining a first current collector is provided,
(A ′ ) A conductive layer for a second electrode made of a matrix pattern or a strip pattern is provided at a position facing both sides of the second insulating base material on both side surfaces of the sheet-like second insulating base material. Obtaining a second current collector,
(B) Oite the surface of each of said first electrode conductive layer, with correspond to the pattern of the first electrode conductive layer, the row and column directions of the matrix pattern, and a length direction of said strip pattern as first exposed portion of the first electrode conductive layer are exposed along either are provided, and the pattern of the first electrode mixture layer was formed, to obtain a first electrode group process,
( B ′ ) On the surface of each second electrode conductive layer, it corresponds to the pattern of the second electrode conductive layer, and any of the row direction and column direction of the matrix pattern, and the length direction of the strip pattern Forming a pattern of the second electrode mixture layer so as to provide a second exposed portion along which the second electrode conductive layer is exposed, and obtaining a second electrode group;
(C) The first exposed portion in the first electrode group and a second gap portion where the second electrode conductive layer is not formed in the second electrode group are opposed to each other, and in the second electrode group The first electrode group and the second electrode with a separator interposed therebetween so that the second exposed portion and the first gap portion where the first electrode conductive layer is not formed in the first electrode group are opposed to each other. and the group are stacked to obtain a laminate process,
(D) A first edge is formed along the first exposed portion of the first electrode group and the second gap portion of the second electrode group, and the first gap of the first electrode group parts and such that the second edge is formed along the second exposed portion of the second electrode group, by disconnecting the laminate, a step of obtaining a plurality of laminated electrode plate group ,
Including, method for producing an electrochemical element. After the step (b) and the step (b '), Oite before the step (c), at least a second electrode assembly of the second gap portions of the surface at the first end edge, said on the surface of the first gap portion of the first electrode assembly in the second edge, each containing a step of forming an insulating material part, the method of manufacturing an electro-chemical device according to claim 1. An end portion of the end portion and the second end edge of said first end edge of the laminated electrode group, each coated with a metal, comprising the step of forming a first terminal and a second terminal, according to claim 1 The manufacturing method of the electrochemical element of description.

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