JP2022127065A - Non-aqueous electrolyte secondary battery and method for manufacturing non-aqueous electrolyte secondary battery - Google Patents

Abstract

To provide a non-aqueous electrolyte secondary battery that is excellent in load characteristics and includes stable conductive connection.SOLUTION: A non-aqueous electrolyte secondary battery 100 comprises: an exterior body in which a negative electrode can 1 and a positive electrode can 2 are insulated and sealed; and an electrode structure that is accommodated in the external body and includes a negative electrode 6 and a positive electrode 8 electrically connected with the negative electrode can 1 and the positive electrode can 2, respectively. The non-aqueous electrolyte secondary battery has adhesive layers 4 formed of a solidified body of conductive paste on inner surfaces of the negative electrode can 1 and the positive electrode can 2. The negative electrode 6 and the positive electrode 8 further include a negative electrode lead tab 5 and a positive electrode lead tab 7 that are electrically connected with the electrodes, respectively, and the negative electrode lead tab 5 and the positive electrode lead tab 7 have a negative electrode connection part 50 and a positive electrode connection part 70, respectively, which include conductive carbon material on surfaces opposite to the negative electrode can 1 and the positive electrode can 2. Laminating the adhesive layers 4, the negative electrode connection part 50, and the positive electrode connection part 70 in a crimped state electrically connects the negative electrode can 1 and the positive electrode can 2 and the negative electrode lead tab 5 and the positive electrode lead tab 7.SELECTED DRAWING: Figure 1

Description

The present invention relates to a non-aqueous electrolyte secondary battery and a method for manufacturing a non-aqueous electrolyte secondary battery.

In a so-called coin-shaped (button-shaped) battery in which an electrode structure serving as a power generation element is housed in a flat cylindrical metal container, the electrode structure has a flat positive electrode and a negative electrode facing each other with a separator interposed therebetween. A configuration using an electrode group formed by winding, stacking, or the like is known. (For example, see Patent Document 1.) Such a battery is excellent in heavy load characteristics and can be used as a main power source for small electronic devices that require a large current supply.
As the positive electrode and the negative electrode that constitute the electrode group of such a battery, a thin plate of metal such as aluminum or copper is used as a current collector, and an active material or the like is formed on the current collector. By electrically connecting the uncoated portion of the current collector and the metal container by welding, the coin-shaped (button-shaped) container can be used as an external terminal.

Japanese Patent Laid-Open No. 2002-200000 discloses that the exposed surface of the current collector and the inner bottom surface of the metal case are connected by conductive connection using a conductive adhesive instead of welding. In this case, since the entire application area of the conductive adhesive can form an effective conductive connection, good conductive connection can be maintained during heavy load discharge even when the electrode group expands and contracts due to charging and discharging.

Japanese Patent Application Laid-Open No. 2008-289260

However, the conductive connection using a conductive adhesive requires a process of drying and solidifying the conductive adhesive after bonding. And until it dries and hardens, the connection remains weak, making it difficult to handle the connection to prevent disconnection.
SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a non-aqueous electrolyte secondary battery having excellent load characteristics and stable conductive connection, and also provides such a non-aqueous electrolyte secondary battery with good workability. The task is to make it.

The non-aqueous electrolyte secondary battery of the present invention comprises: an exterior body in which a first container and a second container are insulated and sealed; and an electrode structure including a first electrode and a second electrode electrically connected to each other, and a solidified body of conductive paste on the inner surface of at least one of the first container and the second container. At least one of the first electrode and the second electrode further includes a lead tab electrically connected to the electrode, the lead tab connecting the first container and the A connecting part containing a conductive carbon material is provided on a surface of the second container facing the container on the connecting side, and the container and the connecting part are laminated by laminating the adhesive layer and the connecting part in a crimped state. It is characterized by being electrically connected to the lead tab.

A method for manufacturing a non-aqueous electrolyte secondary battery according to the present invention includes: an exterior body in which a first container and a second container are insulated and sealed; and an electrode structure including a first electrode and a second electrode electrically connected to the container of the non-aqueous electrolyte secondary battery, wherein the first container and the second forming an adhesive layer on the inner surface of the container by applying and solidifying a conductive paste to the inner surface of at least one of the containers; and at least one of the first electrode and the second electrode. a step of electrically connecting the container and the lead tab by superimposing and crimping a connection portion containing a conductive carbon material formed on the lead tab to be electrically connected to the adhesive layer; characterized by comprising at least

According to the present invention, the layer containing the carbon material formed on the positive electrode connection portion and the negative electrode connection portion of the positive electrode lead tab and the negative electrode lead tab is in contact with the solidified conductive paste formed on the inner surfaces of the positive electrode can and the negative electrode can. Thus, the positive and negative electrodes are electrically connected to the positive and negative electrode cans. By connecting the layers containing the carbon material to each other in a crimped state in this way, the electrical conductivity between the electrode and the container is improved. Moreover, even if the electrode structure composed of the positive electrode and the negative electrode expands or contracts during charging and discharging of the battery, a stable connection state between the lead tab and the container can be maintained. As a result, a battery having stable conductive connection and excellent load characteristics can be obtained.

Further, according to the present invention, a layer containing a carbon material is formed in advance on the positive electrode connection portion and the negative electrode connection portion of the positive electrode lead tab and the negative electrode lead tab, and a solidified conductive paste is formed on the inner surfaces of the positive electrode can and the negative electrode can, respectively. After that, the lead tab and the can are electrically connected by bringing them into contact with each other. As a result, compared to the case where the lead tab and the can are connected with an unsolidified conductive paste (conductive adhesive) and then the conductive paste is dried and solidified, the two can be connected with good workability.

In the non-aqueous electrolyte secondary battery of the present invention, the electrode has a current collector foil made of metal and a mixture layer formed on the current collector foil, and the mixture layer includes an active material and and a conductive aid made of a conductive carbon material, wherein the lead tab is an extension of the current collector foil, and the connecting portion is the mixture layer formed on the lead tab. is.

The method for manufacturing a non-aqueous electrolyte secondary battery according to the present invention further comprises the step of forming the electrode and the lead tab extending from the electrode by forming a mixture layer on a metal current collector foil, In a preferred embodiment, the mixture layer contains an active material and a conductive aid made of a conductive carbon material.

According to the present invention, the positive electrode and the negative electrode can be used as a positive lead tab and a negative lead tab. Thereby, a battery can be produced with better workability.

In a preferred embodiment of the non-aqueous electrolyte secondary battery of the present invention, an uneven portion is formed on the inner surface of the container.

In a preferred embodiment of the method for manufacturing a non-aqueous electrolyte secondary battery of the present invention, an adhesive layer is formed on the inner surface of the container after previously forming uneven portions on the inner surface of the container.

According to the present invention, the contact area between the can and the lead tab can be increased by the uneven portion on the inner surface of the can, so that the resistance of the battery can be reduced. Thereby, a non-aqueous electrolyte secondary battery having particularly excellent load characteristics and reliability can be obtained.

According to the present invention, it is possible to obtain a non-aqueous electrolyte secondary battery having stable conductive connections and excellent load characteristics, and in addition, it is possible to manufacture such a non-aqueous electrolyte secondary battery with good workability. can.

1 is a schematic cross-sectional view for explaining a non-aqueous electrolyte secondary battery that is an embodiment of the present invention; FIG. 1 is a schematic cross-sectional view for explaining an electrode structure that constitutes a non-aqueous electrolyte secondary battery that is an embodiment of the present invention; FIG. FIG. 2 is a schematic cross-sectional view for explaining a non-aqueous electrolyte secondary battery that is another example of an embodiment of the invention; FIG. 3 is a schematic cross-sectional view for explaining a non-aqueous electrolyte secondary battery that is still another example of an embodiment of the invention;

Hereinafter, each embodiment of the non-aqueous electrolyte secondary battery of the present invention will be given, and each configuration will be described in detail with reference to the drawings.

(Non-aqueous electrolyte secondary battery)
An example of the non-aqueous electrolyte secondary battery according to the present embodiment will be described with reference to the drawings.
FIG. 1(a) is a schematic cross-sectional view showing a state in which an electrode structure 10 is arranged inside an exterior body for explaining each component of the non-aqueous electrolyte secondary battery 100 of the present embodiment. Moreover, FIG.1(b) is a schematic sectional drawing which shows the state after sealing a battery.

The non-aqueous electrolyte secondary battery 100 according to the present embodiment is a so-called coin-type (button-type) battery in which an electrode structure is housed in a flat cylindrical metallic outer casing.
More specifically, as shown in FIG. 1(a), a flat cylindrical metallic first container (negative electrode can 1) with one end open and a metallic second container (positive electrode can 2) are provided. are insulated through an insulating gasket 3 . Then, the opening of the positive electrode can 2 is superimposed on the negative electrode can 1 and sealed by caulking to form a hermetically sealed outer package having a housing space formed therein.

The electrode structure 10 is housed in this housing space and electrically connected to the negative electrode can 1 and the positive electrode can 2, respectively, to form a battery. The electrode structure 10 is integrated with a first electrode (negative electrode 6) and a second electrode (positive electrode 8) facing each other with a separator 9 interposed therebetween.
Furthermore, although not shown, an electrolytic solution is sealed in the accommodation space.

The electrode structure 10 includes a sheet-like negative electrode 6 , a positive electrode 8 and a separator 9 . This electrode structure 10 can be accommodated in a container by stacking a negative electrode 6 and a positive electrode 8 via a separator 9 and by winding, stacking, folding, etc. in addition to the winding structure shown in FIG. It can be made into any shape. For example, when the electrode structure 10 is produced by winding, the separator 9 can be sandwiched between both sides of the sheet of the positive electrode 8, and the negative electrode 6 can be overlaid and wound flat.

Here, in this embodiment, the negative electrode lead tab 5 extends from the negative electrode 6 that constitutes the electrode structure 10 . The extended negative electrode lead tab 5 is folded back and positioned between the electrode structure 10 and the negative electrode can 1 . The negative electrode lead tab 5 has a negative electrode connection portion 50 on the surface facing the inner surface 1 a of the negative electrode can 1 . The negative electrode connecting portion 50 is made of a material containing a conductive carbon material. An adhesive layer 4 made of a solidified conductive paste is formed on the inner surface 1a of the negative electrode can 1 .

Similarly, a positive electrode lead tab 7 extends from the positive electrode 8 forming the electrode structure 10 . The extended positive electrode lead tab 7 is folded back and positioned between the electrode structure 10 and the positive electrode can 2 . The positive electrode lead tab 7 has a positive electrode connecting portion 70 on the surface facing the inner surface 2 a of the positive electrode can 2 . The positive electrode connecting portion 70 is made of a material containing a conductive carbon material. An adhesive layer 4 made of solidified conductive paste is formed on the inner surface 2 a of the positive electrode can 2 .

By assembling the battery, each of the members shown in FIG. 1(a) has a structure in which the electrode structure 10 is accommodated in the accommodation space inside the outer package as shown in FIG. 1(b). At this time, the negative electrode connecting portion 50 and the adhesive layer 4 formed on the inner surface 1a are pressure-connected. Thereby, the electrode structure 10 and the negative electrode can 1 are electrically connected. Also, the positive electrode connecting portion 50 and the adhesive layer 4 formed on the inner surface 2a are pressure-connected. Thereby, the electrode structure 10 and the positive electrode can 2 are electrically connected.
In this embodiment, the adhesive layer 4 made of a solidified conductive paste mixed with a carbon material, which will be described later, and the negative electrode connection portion 50 or the positive electrode connection portion 70 containing a conductive carbon material are press-connected. Thus, good electrical connection between the two can be achieved. In addition, the adhesive layer 4, the negative electrode connection portion 50, and the positive electrode connection portion 70 are all made of a soft resin material, and these members are in contact with each other. Even if the configured electrode structure 10 expands or contracts, a stable connection state between the lead tab and the container can be maintained.

Here, in particular, the negative electrode connecting portion 50 or the positive electrode connecting portion 70 of the electrode structure 10 constituting the non-aqueous electrolyte secondary battery of the present embodiment will be described in detail with reference to the drawings. Although the negative electrode 6 and the negative electrode connecting portion 50 are described in FIG. 2, the positive electrode 8 and the positive electrode connecting portion 70 are similarly arranged corresponding to the negative electrode 6 and the negative electrode connecting portion 50, respectively.

FIG. 2 is an enlarged sectional view of the vicinity of the negative electrode lead tab 5 of the electrode structure 10. FIG. The negative electrode 6 has a structure in which a negative electrode mixture 6b is formed on both sides of a negative electrode current collector 6a. In the example shown in FIG. 2( a ), the negative electrode current collector 6 a extends from the end of the negative electrode 6 in the winding direction and further extends in the opposite direction, so that the negative electrode current collector 6 a becomes the negative electrode lead tab 5 . there is A negative electrode connecting portion 50 is formed on one surface of the negative electrode current collector 6a.
This negative electrode connecting portion 50 contains a conductive carbon material. As a specific embodiment, for example, the negative electrode connecting portion 50 can be formed by applying and solidifying a conductive paste obtained by dispersing a conductive carbon material in a resin and an organic solvent. Alternatively, the negative electrode connecting portion 50 can be formed by dispersing a conductive carbon material in a resin to form a sheet, and then adhering the sheet to the negative electrode current collector 6a using a conductive adhesive.
Further, as shown in FIG. 2(b), the negative electrode 6, which is the negative electrode current collector 6a on which the negative electrode mixture 6b containing the conductive carbon material is formed, extends as it is, so that the negative electrode mixture 6b is formed. It may be the negative electrode connection portion 50 .

Although not shown, the positive electrode 8 in which the positive electrode mixture is formed on both sides of the positive electrode current collector is formed on the positive electrode current collector in the same manner as the negative electrode connecting portion 50 extending from the negative electrode 6 described above. The positive electrode connecting portion 70 can be formed by extending the positive electrode 8 containing the positive electrode mixture as it is.

The negative electrode connection portion 50 and the positive electrode connection portion 70 in the present embodiment are made of carbon materials such as graphite, furnace black, ketjen black, and acetylene black, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and styrene butadiene. It is composed of layers fixed by a binder made of rubber (SBR), polyacrylic acid (PA), carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), or the like.
Since these negative electrode connecting portion 50 and positive electrode connecting portion 70 contain a conductive carbon material, they are electrically conductive. and are electrically connected to each other.

A layer containing such a carbon material may also contain materials other than the carbon material and the binder. For example, when the negative electrode lead tab 5 is the extended portion of the negative electrode 6, or when the positive electrode lead tab 7 is the extended portion of the positive electrode 8, the layer containing the carbon material contains a material corresponding to the negative electrode active material of the battery described later. It may be a negative electrode mixture that

The conductive paste is a mixture of a carbon material such as graphite and a resin such as phenolic resin, and is used in the form of a paste dispersed in a solvent such as water. In this embodiment, the conductive paste is applied to the inner surface 1a of the negative electrode can 1 and the inner surface 2a of the positive electrode can 2, and then solidified by a drying process such as heat treatment. It is formed on the inner surface 2 a of the can 2 .

In the present embodiment, the solidified body of the conductive paste formed as described above and the layer containing the carbon material formed on the negative electrode connecting portion 50 and the positive electrode connecting portion 70 are pressure-connected. Such contact between the materials containing the carbon material results in good electrical conductivity between the can and the lead tab. In addition, since the contact is made between soft resin materials, even if the electrode structure 10 composed of the positive electrode 8 and the negative electrode 6 expands or contracts during charging and discharging of the battery, stable connection between the can and the lead tab is ensured. state can be preserved.

Next, another example of this embodiment will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 shows a schematic sectional view (FIG. 3(a)) explaining the arrangement of members before assembly and a schematic sectional view (FIG. 3(b)) after assembly, similar to FIG. FIG. 4 omits a schematic cross-sectional view after assembly, and shows only a schematic cross-sectional view for explaining the arrangement of members before assembly. In addition, in FIG.3(b), illustration of the adhesive layer 4 is abbreviate|omitted for description. Further, explanations of configurations common to the example shown in FIG. 1 are omitted.
As shown in FIGS. 3 and 4, in the present embodiment, it is preferable that an uneven portion 40 is formed on at least one of the inner surface 1a of the negative electrode can 1 and the inner surface 2a of the positive electrode can 2 . The concave-convex portion 40 can be formed by forming a convex portion on the inner surface of the can as shown in FIG. 3, or by forming a concave portion on the inner surface of the can as shown in FIG.
By forming such an uneven portion 40 on the inner surface of the can, the contact area between the can and the lead tab can be increased, and the internal resistance of the battery can be reduced.

When the concave-convex portion 40 is a convex portion as shown in FIG. 3A, a metal mesh is fixed on the inner surface 1a of the negative electrode can 1 or the inner surface 2a of the positive electrode can 2 by bonding, welding, or the like. By doing so, a convex portion can be formed. Alternatively, the projections may be formed by applying a paste containing a carbon material or metal particles in dots or lines and then solidifying the paste.

In addition, when the concave-convex portion 40 is a concave portion as shown in FIG. 4, the concave portion can be formed by cutting a part of the inner surface 1a of the negative electrode can 1 or the inner surface 2a of the positive electrode can 2 . As a method for forming the concave portion, for example, cutting, polishing, etching, or the like can be used.
Further, the recesses and protrusions may be formed on the inner surface 1a of the negative electrode can 1 or the inner surface 2a of the positive electrode can 2 by combining the above-described methods.

In the example shown in FIGS. 3 and 4, on the uneven portion 40 formed on the inner surface 1a of the negative electrode can 1 or the inner surface 2a of the positive electrode can 2, an adhesive layer 4 made of the above-described solidified conductive paste is further formed. ing. As shown in the example of FIG. 3(b), the contact area between the uneven portion 40 on which the adhesive layer 4 is formed and the connection portion of the lead tab is increased, thereby improving the conductivity and improving the load characteristics of the battery. can be

A known material can be used for the material constituting the non-aqueous electrolyte secondary battery in the present embodiment.
The negative electrode can 1 is formed in a flat cylindrical shape with one end open. Further, as shown in FIGS. 1 to 4, the negative electrode can 1 may be folded back at the end on the opening side, or may be formed in a multistage cylindrical shape. The negative electrode can 1 can be formed by drawing a stainless steel plate. Examples of stainless steel materials include SUS316L, SUS329J4L, and SUS304. As the material of the negative electrode can, for example, a clad material obtained by press-bonding copper, nickel, or the like to stainless steel may be used.

The positive electrode can 2 is formed in a flat cylindrical shape with one end open. The positive electrode can 2 can be formed by drawing a stainless steel plate. Examples of stainless steel materials include SUS316L and SUS329J4L.

The gasket 3 is made of an insulating member formed in an annular shape, is interposed between the negative electrode can 1 and the positive electrode can 2, and insulates and holds them.
Materials for the gasket 3 include, for example, polypropylene resin (PP), polyphenyl sulfide (PPS), polyethylene terephthalate (PET), polyamide, liquid crystal polymer (LCP), and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA). , polyether ether ketone resin (PEEK), polyether nitrile resin (PEN), polyether ketone resin (PEK), polyarylate resin, polybutylene terephthalate resin (PBT), polycyclohexane dimethylene terephthalate resin, polyether sulfone resin ( PES), polyaminobismaleimide resin, polyetherimide resin, and plastic resin such as fluororesin.

Further, a sealing agent may be further arranged between the negative electrode can 1 or the positive electrode can 2 and the gasket 3 in order to improve the sealing performance of the container. As the sealing agent, for example, asphalt, epoxy resin, polyamide resin, butyl rubber adhesive, or the like can be used.

The negative electrode 6 is formed by coating a negative electrode mixture 6b including a negative electrode active material, a conductive aid, and a binder on a negative electrode current collector 6a. More specifically, the negative electrode 6 is obtained by coating the negative electrode current collector 6a with a paste negative electrode mixture diluted with an organic solvent and then drying the negative electrode current collector 6a to remove the organic solvent. can be done.

The negative electrode current collector 6a is a metal thin film having a thickness of 100 μm or less, and copper, aluminum, or the like can be used as the metal. The negative electrode lead tab 5 is composed of a metal thin film from which the negative electrode current collector 6a extends. Further, the negative electrode lead tab 5 may be formed by attaching copper, nickel, aluminum or the like to the extending portion of the negative electrode current collector 6a by welding or the like.

A known material used for non-aqueous electrolyte secondary batteries can be used as the negative electrode active material. Examples of negative electrode active materials include carbon materials such as hard carbon, soft carbon, and graphite, silicon oxide represented by SiO _x (0<x<2), lithium titanate (Li ₄ Ti ₅ O ₁₂ ), Si, Various materials such as WO ₂ , WO ₃ and Li—Al alloys can be mentioned.

Carbonaceous materials such as furnace black, ketjen black, acetylene black, and graphite can be used as the conductive aid contained in the negative electrode mixture 6b. In addition, one of the above conductive agents may be used alone, or two or more thereof may be used in combination.

Examples of the binder contained in the negative electrode mixture 6b include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), polyacrylic acid (PA), carboxymethylcellulose (CMC), Polyvinyl alcohol (PVA) or the like can be used. Moreover, one of the above binders can be used alone, or two or more of them can be used in combination.

The positive electrode 8 is formed by coating a positive electrode mixture 8b including a positive electrode active material, a conductive aid, and a binder on a positive electrode current collector 8a. More specifically, the cathode 8 is obtained by coating the cathode current collector 8a with the cathode mixture 8b diluted with an organic solvent and made into a paste, and then drying the cathode current collector 8a to remove the organic solvent. be able to.

The positive electrode current collector 8a is a metal thin film having a thickness of 100 μm or less, and aluminum or the like can be used as the metal. The positive electrode lead tab 7 is composed of a metal thin film from which the positive electrode current collector 8a extends. The positive electrode lead tab 7 may be formed by attaching aluminum or the like to the extending portion of the positive electrode current collector 8a by welding or the like.

As the positive electrode active material, known materials used for non-aqueous electrolyte secondary batteries can be used. Examples of the positive electrode active material include various materials such as lithium manganese oxide, molybdenum oxide, lithium iron phosphate compound, lithium cobalt oxide, lithium nickel oxide, and vanadium oxide.

As the conductive aid and the binder contained in the positive electrode mixture 8b, various materials mentioned above as the conductive aid and the binder contained in the negative electrode mixture 6b can be used.

The separator 9 is a member having a characteristic of allowing lithium ions to pass therethrough. The separator 9 is formed of, for example, a polyolefin resin porous film, a glass nonwoven fabric, a resin nonwoven fabric, a laminate of cellulose fibers, or the like.

A non-aqueous electrolyte in which a supporting salt is dissolved in a non-aqueous solvent can be used as the electrolytic solution.
As the non-aqueous solvent, various compounds such as cyclic carbonates, chain carbonates and chain ethers can be used. These are for example gamma-butyrolactone (GBL), propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), methyl Organic solvents such as mate, 1,2-dimethoxyethane (DME), tetrahydrofuran (THF), dioxolane, dimethylformamide (DMF), glyme, sulfolane, and acetonitrile can be used singly or in combination. Moreover, as the supporting salt, for example, LiClO ₄ , LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiN(SO ₂ F) 2 or the like can be employed.

Examples of supporting electrolytes that can be used include LiClO ₄ , LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiN(SO ₂ F) ₂ and the like. Also, an ionic liquid may be used as the supporting salt.

In addition to these solvents and supporting salts, various additives can be added.
Furthermore, in place of the electrolytic solution, a gel electrolyte obtained by impregnating and occluding these non-aqueous electrolytic solutions in a highly absorbent porous polymer, or a solid solution of the lithium salt in a polymer such as polyethylene oxide or polyphosphazene crosslinked body. It is also possible to use a polymer solid electrolyte obtained by forming a polymer, or an inorganic solid electrolyte such as Li ₃ N or LiI.

It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways within its technical scope.
For example, in the present embodiment, a coin-shaped (button-shaped) container is used as an example. The present invention is not limited to this structure, and any structure may be employed as long as the positive electrode can and the negative electrode can are sealed in a mutually insulated state and are electrically connected to the negative electrode lead tab 5 and the positive electrode lead tab 7. For example, a flat positive electrode can and The negative electrode can may be an exterior body having a structure in which a cylindrical insulating member made of glass or ceramic is sandwiched. Also, the shape is not limited to a coin type (button type), and may be, for example, a rectangular outer body.

Further, the negative electrode lead tab 5 and the positive electrode lead tab 7 do not necessarily have to be extensions of the negative electrode 6 and the positive electrode 8, and a separate lead tab may be attached to the electrodes by welding or the like.

In addition, it is possible to appropriately replace the components in the above-described embodiments with well-known components without departing from the scope of the present invention.

(Manufacturing method of non-aqueous electrolyte secondary battery)
Next, a method for manufacturing the non-aqueous electrolyte secondary battery of this embodiment will be described.
The method for manufacturing the non-aqueous electrolyte secondary battery of the present embodiment includes steps of combining a positive electrode and a negative electrode to form an electrode structure, connecting the electrode structure to a positive electrode can and a negative electrode can, and connecting the negative electrode can to the positive electrode. and a step of crimping and sealing the can to form a battery.

First, the process of manufacturing an electrode structure by combining a positive electrode and a negative electrode will be described. First, the sheet-like separator 9 is folded in two and the sheet-like positive electrode 8 is sandwiched between them. Next, by stacking the negative electrode 6 on the positive electrode 8 sandwiched between the separators 9, a laminate is obtained in which the positive electrode 8 and the negative electrode 6 face each other with the separator 9 interposed therebetween. By flatly winding this laminate, the electrode structure 10 of the non-aqueous electrolyte secondary battery 100 can be obtained.

The electrode structure 10 can be formed into a shape that can be accommodated inside the exterior body by various methods such as winding, lamination, and folding as described above.

Here, each of the negative electrode 6 and the positive electrode 8 is arranged so that a part thereof protrudes from the separator 9 . The protruding negative electrode 6 and positive electrode 8 are used as the negative electrode lead tab 5 and the positive electrode lead tab 7, respectively. The negative electrode lead tab 5 and the positive electrode lead tab 7 are separately arranged above and below the electrode structure 10 so as not to overlap each other.

Next, the process of connecting the electrode structure to the positive can and the negative can will be described.
First, the inner surface 1a of the negative electrode can 1 and the inner surface 2a of the positive electrode can 2 are etched to form recesses, thereby forming the uneven portion 40 . Next, a conductive paste, which is a mixture of graphite and phenolic resin, is applied to the positions of the inner surfaces 1a and 2a, and dried to solidify the paste to form the adhesive layer 4. As shown in FIG.
Here, when forming the concave-convex portion 40, as described above, in addition to forming concave portions, convex portions may also be formed.
Next, the electrode structure 10 is placed on the inner surface 2 a of the positive electrode can 2 so that the positive electrode connecting portion 70 of the positive electrode lead tab 7 faces the inner surface 2 a of the positive electrode can 2 . Further, after the electrolytic solution is injected into the positive electrode can 2, the negative electrode can 1 with the gasket 3 attached thereto is arranged and pushed into the positive electrode can 2 from above so as to overlap. At this time, the negative electrode connecting portion 50 of the negative electrode lead tab 5 is arranged to face the inner surface 1 a of the negative electrode can 1 .

Then, the battery is crimped and sealed so that the opening of the positive electrode can 2 is tilted toward the negative electrode can 1 side. As a result, the adhesive layer 4 formed on the inner surface 2 a of the positive electrode can 2 and the positive electrode connecting portion 70 are pressure-connected, and the uneven portion 40 bites into the positive electrode connecting portion 70 . Further, the adhesive layer 4 formed on the inner surface 1 a of the negative electrode can 1 and the negative electrode connecting portion 50 are connected by pressure contact, and the uneven portion 40 bites into the negative electrode connecting portion 50 . In this way, the non-aqueous electrolyte secondary battery 100 is assembled by electrically connecting the positive electrode 8 and the positive electrode can 2, and the negative electrode 6 and the negative electrode can 1, respectively.

DESCRIPTION OF SYMBOLS 100... Nonaqueous electrolyte secondary battery 1... Negative electrode can 1a... Inner surface of negative electrode can 2... Positive electrode can 2a... Inner surface of positive electrode can 3... Gasket 4... Adhesive layer 40 . electrode structure

Claims (6)

an outer body formed by insulating and sealing a first container and a second container; a first electrode housed in the outer body and electrically connected to the first container and the second container, respectively; an electrode structure including a second electrode;
Having an adhesive layer made of a solidified conductive paste on the inner surface of at least one of the first container and the second container,
At least one of the first electrode and the second electrode further includes a lead tab electrically connected to the electrode, and the lead tab connects the first container and the second container. Having a connection part containing a conductive carbon material on the surface facing the container on the side,
A non-aqueous electrolyte secondary battery, wherein the container and the lead tab are electrically connected by laminating the adhesive layer and the connecting portion in a pressure-bonded state. The electrode has a metal current collector foil and a mixture layer formed on the current collector foil,
The mixture layer contains an active material and a conductive aid made of a conductive carbon material,
2. The non-aqueous electrolyte secondary battery according to claim 1, wherein said lead tab is an extension of said current collector foil, and said connecting portion is said mixture layer formed on said lead tab. 3. The non-aqueous electrolyte secondary battery according to claim 1, wherein an uneven portion is formed on the inner surface of the container. an outer body formed by insulating and sealing a first container and a second container; a first electrode housed in the outer body and electrically connected to the first container and the second container, respectively; A method for manufacturing a non-aqueous electrolyte secondary battery comprising an electrode structure including a second electrode,
a step of applying a conductive paste to the inner surface of at least one of the first container and the second container and solidifying it to form an adhesive layer on the inner surface of the container;
A connection portion containing a conductive carbon material formed on a lead tab electrically connected to at least one of the first electrode and the second electrode is superimposed on the adhesive layer and crimped. and a step of electrically connecting the container and the lead tab. further comprising a step of forming the electrode and the lead tab extending from the electrode by forming a mixture layer on a metal current collector foil;
5. The method of manufacturing a non-aqueous electrolyte secondary battery according to claim 4, wherein the mixture layer contains an active material and a conductive aid made of a conductive carbon material. 6. The method for manufacturing a non-aqueous electrolyte secondary battery according to claim 4, further comprising forming an adhesive layer on the inner surface of the container after previously forming uneven portions on the inner surface of the container.

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