WO2023033173A1

WO2023033173A1 - Secondary battery

Info

Publication number: WO2023033173A1
Application number: PCT/JP2022/033284
Authority: WO
Inventors: 宏之泉井
Original assignee: 株式会社村田製作所
Priority date: 2021-09-06
Filing date: 2022-09-05
Publication date: 2023-03-09

Abstract

Provided is a secondary battery comprising: an outer package; and an electrode assembly housed inside the outer package. In such a secondary battery, the outer package has an opening, and a sealing structure is provided so as to close the opening. The sealing structure includes a terminal portion and a sealing portion, the terminal portion has a second sealing portion and a terminal electrode provided on the second sealing portion, and the sealing portion is interposed between the second sealing portion and the outer package.

Description

secondary battery

The present disclosure relates to secondary batteries. In particular, the present disclosure relates to a secondary battery with an electrode assembly comprising an electrode layer comprising a positive electrode, a negative electrode and a separator.

Secondary batteries are so-called storage batteries, so they can be charged and discharged repeatedly, and are used for a variety of purposes. For example, secondary batteries are used in mobile devices such as mobile phones, smart phones, and laptop computers.

JP 2019-046639 A

The inventors of the present application realized that conventional secondary batteries had problems to be overcome, and found it necessary to take measures to address them. Specifically, the inventors of the present application have found that there are the following problems.

For example, as shown in FIG. 11, a conventional secondary battery 100 generally includes an electrode assembly 110 (a positive electrode, a negative electrode, and an electrode structure layer including a separator between them), and this electrode. It has a metallic outer casing 120 that can enclose the assembly 110 together with an electrolyte (not shown).

For example, the exterior body 120 may be provided with an opening 121 . A tab 111 that can extend from the electrode assembly 110 is electrically connected to the metal plate 130 through this opening 121 . The metal plate 130 can be indirectly connected to the exterior body 120 through an insulating sealing member 140 such as resin to form either a positive or a negative terminal electrode.

In general, the conventional insulating seal member 140, which can be made of resin or the like, has a risk that moisture such as water vapor may permeate therethrough, and a volatilized electrolytic solution may permeate to the outside. We found that there is room for improvement. It was also found that there is a possibility that a gas passage may be formed between the sealing member 140 and the exterior body 120, and that there is room for further improvement and improvement in the airtightness of the conventional secondary battery.

This disclosure has been made in view of such problems. That is, a main object of the present disclosure is to provide a secondary battery with improved airtightness.

The inventors of the present application have attempted to solve the above problems by dealing with them in a new direction, rather than dealing with them on the extension of the conventional technology. As a result, the secondary battery of the present disclosure, which achieves the above main object, was achieved.

In order to further improve the airtightness, the inventors of the present application have proposed inorganic sealing materials such as metal and/or glass that are excellent in preventing permeation of moisture such as water vapor ( In other words, we considered using a "non-resin sealing material").

As a result of intensive research, for example, an electrode assembly 10 formed by laminating a positive electrode 1, a negative electrode 2, and an electrode configuration layer 5 including a separator 3 therebetween as shown in FIGS. 1 and 2, and such an electrode assembly. For example, an inorganic sealing material (that is, a "non-resin sealing material") is included around an opening 21 of a metallic exterior body 20 that can accommodate the three-dimensional body 10 together with an electrolytic solution (not shown). It has been found that the airtightness can be further improved by providing the sealing portion (first sealing portion) 50 composed of the first sealing portion. In addition, by using the terminal portion 40 having an unprecedented novel structure, which includes such a sealing portion 50 as well as a further sealing portion (second sealing portion) 41 and a terminal electrode 42, It was found that the permeation-preventing property of volatilized electrolytic solution can be easily improved in addition to the permeation-preventing property of moisture such as water vapor.

The present disclosure provides a secondary battery that includes an exterior body and an electrode assembly housed inside the exterior body. In the secondary battery, the exterior body has an opening, and a sealing structure is provided so as to close the opening. The sealing structure includes a terminal portion and a sealing portion (first a sealing portion), wherein the first terminal portion includes a second sealing portion and a terminal electrode provided on the second sealing portion; A sealing portion is interposed between the second sealing portion and the exterior body.

According to the present disclosure, a secondary battery with excellent airtightness is obtained. It should be noted that the effects described in this specification are only examples and are not limited, and additional effects may be provided.

FIG. 1 is a cross-sectional view schematically showing the configuration of the electrode assembly (FIG. 1(A): electrode assembly with planar lamination type structure, FIG. 1(B): electrode assembly with wound lamination type structure). . FIG. 2 is a schematic cross-sectional view schematically showing the secondary battery according to the first embodiment of the present disclosure. FIG. 3 is a schematic cross-sectional view schematically showing a modification of the secondary battery according to the first embodiment of the present disclosure. FIG. 4 is a schematic cross-sectional view schematically showing variations of the terminal portion. FIG. 5 is a schematic top view schematically showing variations in arrangement of terminal electrodes (round secondary battery). FIG. 6 is a schematic top view schematically showing variations in arrangement of terminal electrodes (a prismatic secondary battery). FIG. 7 is a schematic cross-sectional view schematically showing a secondary battery according to a second embodiment of the present disclosure. FIG. 8 is a schematic cross-sectional view schematically showing a modification of the secondary battery according to the second embodiment of the present disclosure. FIG. 9 is a schematic diagram schematically showing a clad material that can be used as a metal part. FIG. 10 is a schematic cross-sectional view schematically showing a method of manufacturing a secondary battery. FIG. 11 is a schematic cross-sectional view schematically showing a conventional secondary battery.

Below, the present disclosure will be described in more detail by citing a secondary battery according to one embodiment of the present invention. Although the description will be made with reference to the drawings as necessary, the various elements in the drawings are only schematically and exemplarily shown for understanding of the present invention, and the external appearance and/or dimensional ratios are not the same as the actual ones. can differ.

The "cross-sectional view" directly or indirectly described in this specification is based on a virtual cross section of the secondary battery. Similarly, the direction of “thickness” described directly or indirectly in this specification, for example, in the case of “a secondary battery having a plate-like thickness”, corresponds to the plate thickness direction of such a secondary battery. . As used herein, "plan view" or "plan view shape" is based on a perspective view of an object viewed from above or below.

Also, the terms "vertical direction" and "horizontal direction" used directly or indirectly in this specification correspond to the vertical direction and the lateral direction in the drawings, respectively. Unless otherwise specified, the same reference numerals or symbols indicate the same members or parts or the same meanings. In one exemplary aspect, the downward vertical direction (ie, the direction in which gravity acts) can be considered to correspond to the "downward direction", and the opposite direction to the "upward direction".

[Basic configuration of secondary battery]
A "secondary battery" as used herein refers to a battery that can be repeatedly charged and discharged. Therefore, the secondary battery of the present disclosure is not overly bound by its name, and can include, for example, power storage devices.

The secondary battery of the present disclosure includes, for example, an electrode assembly formed by laminating electrode constituent layers including a positive electrode, a negative electrode, and a separator. For example, FIGS. 1A and 1B schematically illustrate an electrode assembly 10. FIG. As shown in the figure, the positive electrode 1 and the negative electrode 2 may be stacked with the separator 3 in between to form an electrode-constituting layer 5 . The electrode assembly 10 may be configured by stacking at least one or more such electrode configuration layers 5 . In FIG. 1A, the electrode configuration layer 5 has a planar laminated structure in which the electrode constituent layers 5 are laminated in a planar manner. On the other hand, in FIG. 1B, the electrode structure layer 5 has a wound laminated structure in which it is wound in a wound shape. That is, in FIG. 1(B), the wound laminated structure ( For example, it has a jelly roll structure).
In other words, the electrode assembly 10 may have a planar laminated structure in which the electrode constituent layers 5 are laminated so as to be stacked on each other, as shown in FIG. 1(A), for example. Alternatively, the electrode assembly 10 may have a wound laminated structure in which the electrode configuration layer 5 extending in a belt shape relatively long is wound in a roll, as shown in FIG. 1B, for example. good.
Note that FIG. 1(B) merely illustrates the winding laminate type structure of the electrode assembly, and the electrode assembly is wrapped with the cross section shown in FIG. 1(B) facing upward or downward. May be placed inside the body.

The planar lamination type structure or winding type structure is merely an example as the structure of the electrode assembly. In other words, the structure of the electrode assembly is not necessarily limited to a planar laminated structure (see FIG. 1(A)) or a wound laminated structure (see FIG. 1(B)). and the negative electrode on a long film and then folded, so-called stack-and-fold structure.

In the secondary battery of the present disclosure, such an electrode assembly may be enclosed in an outer package together with an electrolytic solution (eg, non-aqueous electrolytic solution). For example, the electrode assembly may be enclosed in the outer package together with a liquid electrolyte (eg, an electrolytic solution, which in some embodiments contains an organic solvent or the like).

The positive electrode is composed of at least a positive electrode material layer and, if necessary, a positive electrode current collector. In the positive electrode, for example, a positive electrode material layer is provided on at least one side of a positive electrode current collector. The cathode material layer contains a cathode active material as an electrode active material. For example, each of the plurality of positive electrodes in the electrode assembly may be provided with a positive electrode material layer on both sides of the positive electrode current collector, or may be provided with a positive electrode material layer only on one side of the positive electrode current collector. Anything is fine. For example, the positive current collector may have a foil form. That is, the positive electrode current collector may be made of metal foil.

The negative electrode is composed of at least a negative electrode material layer and, if necessary, a negative electrode current collector. In the negative electrode, for example, a negative electrode material layer is provided on at least one side of a negative electrode current collector. The negative electrode material layer contains a negative electrode active material as an electrode active material. For example, each of the plurality of negative electrodes in the electrode assembly may be provided with a negative electrode material layer on both sides of the negative electrode current collector, or may be provided with a negative electrode material layer only on one side of the negative electrode current collector. Anything is fine. For example, the negative electrode current collector may have a foil form. That is, the negative electrode current collector may be made of metal foil.

The electrode active materials that can be contained in the positive electrode material layer and the negative electrode material layer, that is, the positive electrode active material and the negative electrode active material, respectively, are substances that can directly participate in the transfer of electrons in the secondary battery, and charge and discharge, that is, the battery reaction. It is the main material of the positive electrode and the negative electrode that is responsible for

More specifically, ions can be brought to the electrolyte due to the "positive electrode active material that may be contained in the positive electrode material layer" and the "negative electrode active material that may be contained in the negative electrode material layer". Such ions can move between the positive electrode and the negative electrode to transfer electrons and charge and discharge.

The positive electrode material layer and the negative electrode material layer may be layers capable of intercalating and deintercalating lithium ions. In other words, the secondary battery according to one embodiment of the present invention is a non-aqueous electrolyte secondary battery in which lithium ions move between the positive electrode and the negative electrode via the non-aqueous electrolyte and the battery can be charged and discharged. It's okay.

When lithium ions are involved in charging and discharging, the secondary battery according to one embodiment of the present invention can correspond to a so-called "lithium ion battery". A lithium ion battery has a layer in which a positive electrode and a negative electrode can intercalate and deintercalate lithium ions.

The positive electrode active material of the positive electrode layer may be composed of, for example, granules, and the positive electrode layer may contain a binder for more sufficient contact and shape retention between the particles. A conductive aid may be contained in the positive electrode material layer in order to facilitate the electron transfer that promotes the battery reaction.

The negative electrode active material of the negative electrode layer may be composed of, for example, granules, and the negative electrode layer may contain a binder for more sufficient contact and shape retention between the particles. A conductive aid may be contained in the negative electrode material layer in order to facilitate the electron transfer that promotes the battery reaction.

Because of the form in which a plurality of components are contained in this way, the positive electrode material layer and the negative electrode material layer can also be called "positive electrode mixture layer" and "negative electrode mixture layer", respectively.

The positive electrode active material may be, for example, a material that contributes to intercalation and deintercalation of lithium ions. From this point of view, the positive electrode active material may be, for example, a lithium-containing composite oxide. More specifically, the positive electrode active material may be a lithium transition metal composite oxide containing lithium and at least one transition metal selected from the group consisting of cobalt, nickel, manganese and iron.

That is, the positive electrode material layer of the secondary battery according to one embodiment of the present invention may contain such a lithium-transition metal composite oxide as a positive electrode active material. For example, the positive electrode active material may be lithium cobaltate, lithium nickelate, lithium manganate, lithium iron phosphate, or a transition metal thereof partially replaced by another metal.

Although such a positive electrode active material may be contained as a single species, it may also be contained in combination of two or more species.

The binder that can be contained in the positive electrode material layer is not particularly limited. Examples of binders for the positive electrode layer include polymer compounds. More specifically, styrene-butadiene-based rubber, polyacrylic acid, polyimide-based resin, polyamideimide-based resin, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer and At least one selected from the group consisting of polytetrafluoroethylene and the like can be used as a binder for the positive electrode material layer.

The conductive aid that can be contained in the positive electrode material layer is not particularly limited. For example, the conductive additive for the positive electrode layer includes carbon black such as thermal black, furnace black, channel black, ketjen black and/or acetylene black, graphite such as natural graphite and/or artificial graphite, carbon nanotubes and/or At least one selected from carbon fibers such as vapor-grown carbon fibers, metal powders such as copper, nickel, aluminum and/or silver, and polyphenylene derivatives.

The thickness of the positive electrode material layer is not particularly limited. For example, the thickness dimension of the positive electrode material layer may be 1 μm or more and 300 μm or less, for example, 5 μm or more and 200 μm or less. The thickness dimension of the positive electrode material layer is the thickness inside the secondary battery, and the average value of the measured values at arbitrary 10 points may be adopted.

The negative electrode active material may be a material that contributes to intercalation and deintercalation of lithium ions. From this point of view, the negative electrode active material may be, for example, various carbon materials, oxides, and/or lithium alloys, metallic lithium, and the like.

Examples of various carbon materials for the negative electrode active material include graphite (more specifically, natural graphite and/or artificial graphite), hard carbon, soft carbon, and/or diamond-like carbon. For example, graphite has high electron conductivity and, for example, excellent adhesion to a negative electrode current collector.

As the oxide of the negative electrode active material, at least one selected from the group consisting of silicon oxide, tin oxide, indium oxide, zinc oxide and lithium oxide can be mentioned.

Such an oxide may be amorphous as its structural form. This is because deterioration due to non-uniformity such as grain boundaries or defects is less likely to occur.

The lithium alloy of the negative electrode active material may be any metal alloy capable of forming an alloy with lithium. It may be a binary, ternary or higher alloy of lithium with metals such as Zn and/or La.

Such an alloy may be amorphous as its structural form, for example. This is because deterioration due to non-uniformity such as grain boundaries or defects is less likely to occur.

The binder that can be contained in the negative electrode material layer is not particularly limited. Examples of binders for the negative electrode material layer include polymer compounds. More specifically, styrene-butadiene-based rubber, polyacrylic acid, polyimide-based resin, polyamideimide-based resin, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer and At least one selected from the group consisting of polytetrafluoroethylene and the like can be used as a binder for the negative electrode material layer.

The conductive aid that can be contained in the negative electrode material layer is not particularly limited. For example, the conductive aid for the negative electrode layer may be thermal black, furnace black, channel black, carbon black such as ketjen black and/or acetylene black, graphite such as natural graphite and/or artificial graphite, carbon nanotubes and/or At least one selected from carbon fibers such as vapor-grown carbon fibers, metal powders such as copper, nickel, aluminum and/or silver, and polyphenylene derivatives.

The thickness dimension of the negative electrode material layer is not particularly limited. For example, the dimension of the negative electrode material layer may be 1 μm or more and 300 μm or less, such as 5 μm or more and 200 μm or less. The thickness dimension of the negative electrode material layer is the thickness inside the secondary battery, and the average value of the measured values at arbitrary 10 points may be adopted.

The positive electrode current collector and negative electrode current collector that can be used for the positive electrode and the negative electrode are members that can collect and supply electrons generated in the electrode active material due to the battery reaction. Such an electrode current collector may be a sheet-like metal member. Also, such electrode current collectors may have a porous or perforated morphology. For example, the current collector may be a plate, metal foil, perforated metal, mesh and/or expanded metal, and the like.

The positive electrode current collector that can be used for the positive electrode may consist of a metal foil containing at least one selected from the group consisting of aluminum, stainless steel (SUS), nickel, and the like. The positive electrode current collector may be, for example, aluminum foil.

The negative electrode current collector that can be used for the negative electrode may consist of a metal foil containing at least one selected from the group consisting of copper, stainless steel (SUS), nickel, and the like. The negative electrode current collector may be, for example, copper foil.

In the present disclosure, "stainless steel" (SUS) refers to, for example, stainless steel defined in "JIS G 0203 Iron and Steel Terms", and is an alloy steel containing chromium or chromium and nickel good.

Each thickness dimension of the positive electrode current collector and the negative electrode current collector is not particularly limited. For example, each thickness dimension of the positive electrode current collector and the negative electrode current collector may be 1 μm or more and 100 μm or less, for example, 10 μm or more and 70 μm or less. Each thickness dimension of the positive electrode current collector and the negative electrode current collector is the thickness inside the secondary battery, and an average value of measured values at arbitrary 10 points may be adopted.

The separator that can be used for the positive electrode and the negative electrode is a member that can be provided from the viewpoint of preventing short circuits due to contact between the positive electrode and the negative electrode and/or retaining the electrolyte. In other words, the separator is a member that allows ions to pass through while preventing electronic contact between the positive electrode and the negative electrode.

For example, the separator is a porous or microporous insulating member and may have a membrane form due to its small thickness. By way of example only, a polyolefin microporous membrane may be used as the separator.

A microporous membrane that can be used as a separator may contain, for example, only polyethylene (PE) or only polypropylene (PP) as polyolefin. Furthermore, the separator may be a laminate that can be composed of a "PE microporous membrane" and a "PP microporous membrane". The surface of the separator may be covered with an inorganic particle coat layer and/or an adhesive layer or the like. The surface of the separator may have adhesiveness.

The thickness dimension of the separator is not particularly limited. For example, the thickness dimension of the separator may be 1 μm or more and 100 μm or less, for example, 2 μm or more and 20 μm or less. The thickness dimension of the separator is the thickness inside the secondary battery (particularly the thickness between the positive electrode and the negative electrode), and the average value of the measured values at arbitrary 10 points may be adopted.

In the present disclosure, the separator should not be particularly bound by its name, and may be a solid electrolyte, a gel electrolyte, and/or insulating inorganic particles that can have similar functions.

For the positive electrode, for example, a positive electrode layer slurry prepared by mixing a positive electrode active material, optionally a binder, and optionally a conductive aid in a dispersion medium (for example, a medium such as an organic solvent) is used as a positive current collector. It can be obtained by applying it to the body, drying it, and then rolling the dry coating with a roll press or the like.

For the negative electrode, for example, a negative electrode layer slurry prepared by mixing a negative electrode active material, optionally a binder, and optionally a conductive aid in a dispersion medium (for example, a medium such as an organic solvent) is used as a negative current collector. It can be obtained by applying it to the body, drying it, and then rolling the dry coating with a roll press or the like.

In a secondary battery according to an embodiment of the present invention, for example, an electrode assembly including an electrode configuration layer including a positive electrode, a negative electrode, and a separator may be enclosed in an exterior body together with an electrolyte. The electrolyte can assist in the migration of metal ions released from the electrodes (positive and/or negative electrodes). The electrolyte may be a “non-aqueous” electrolyte comprising organic electrolytes and/or organic solvents, etc., or an “aqueous” electrolyte comprising water.

When the positive electrode and the negative electrode have layers capable of intercalating and deintercalating lithium ions, for example, the electrolyte may be a lithium-in containing electrolyte or an organic electrolyte and/or a "non-aqueous" electrolyte containing an organic solvent. That is, the electrolyte may be a non-aqueous electrolyte. In the electrolyte, metal ions released from the electrodes (positive and/or negative electrodes) will be present, and therefore the electrolyte can assist in the movement of metal ions in the battery reactions.

A secondary battery according to an embodiment of the present invention may be a non-aqueous electrolyte secondary battery using a "non-aqueous" electrolyte containing a "non-aqueous" solvent and a solute as the electrolyte. The electrolyte may have a form such as liquid or gel (note that the "liquid" non-aqueous electrolyte can also be referred to as "non-aqueous electrolyte liquid" in the present disclosure).

The non-aqueous electrolyte may be an electrolyte containing a non-aqueous solvent and a solute. A specific solvent for the non-aqueous electrolyte may contain at least carbonate. Such carbonates may be cyclic carbonates and/or linear carbonates.

Although not particularly limited, cyclic carbonates include at least one selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC) and vinylene carbonate (VC). be able to.

Examples of chain carbonates include at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC) and dipropyl carbonate (DPC).

By way of example only, in one preferred embodiment of the present invention, a combination of cyclic carbonates and linear carbonates may be used as the non-aqueous electrolyte, such as ethylene carbonate (EC) and diethyl carbonate ( DEC), a mixture of ethylene carbonate (EC) and ethylmethyl carbonate (EMC), and the like may be used.
A conventional solute may be used as the solute of the non-aqueous electrolyte. A specific solute of the non-aqueous electrolyte is not particularly limited, but Li salts such as LiPF ₆ and/or LiBF ₄ may be used.

In the present disclosure, the "armor" of a secondary battery generally means a part, member or structure that can house or enclose an electrode assembly including an electrode configuration layer comprising a positive electrode, a negative electrode and a separator. The exterior body may be an exterior body having electrical conductivity or conductivity, or may be a metal exterior body. Also, such a metal sheath may have a two-part construction that may be composed of a cup-shaped member and a lid-shaped member.

In the present disclosure, the “cup-shaped member” has a side surface corresponding to the body and a main surface (typically, for example, a bottom or a lower surface) that is continuous therewith, and has a hollow inside. means the material to be obtained. In the present disclosure, the term “lid-shaped member” refers to a member that is combined to cover such a cup-shaped member (preferably, the inner hollow portion of the cup-shaped member is in contact with the side wall of the cup-shaped member. means a member provided to isolate from the The lid-shaped member is, for example, a single member (typically a plate-shaped member) that generally extends in a plane direction (particularly, a direction perpendicular to the direction in which the side wall of the cup-shaped member extends vertically). In particular, it may be a member provided so as to be in contact with the side wall of the cup-shaped member. As will be described later, the lid-shaped member in the present disclosure may be provided with a step (S) as shown in FIG. 2, for example.

The sheath may be provided with openings, for example, for passage of tabs or the like that may extend from the electrode assembly. The shape of the opening is not particularly limited. For example, the planar shape of the opening of the exterior body may have a geometric shape such as a circle, a square, or a rectangle. In addition, there is no particular limitation on the dimensions of the opening of the exterior body.
The opening can be provided at a desired position of the exterior body, and there is no particular limitation on the location of the opening. The opening may be provided in either the lid-shaped member or the cup-shaped member of the exterior body.

In the exterior body, the lid-shaped member and the cup-shaped member may be arbitrarily combined so that the upper end portions of the lid-shaped member and the cup-shaped member are engaged, coupled or fitted to each other.

The cup-shaped member and the lid-shaped member may be joined together by a welding process, which may allow relatively simple encapsulation of the electrode assembly.

The thickness of the exterior body may be, for example, 1 mm or more. The thickness of the exterior body is preferably 4 mm, more preferably 5 mm or more, and its upper limit is, for example, 200 mm or less.

In the present disclosure, "tab" means a conductive member or lead that can be electrically connected to the positive or negative electrode of the electrode assembly and can protrude or extend from the electrode assembly.
The tab can be in electrical contact with a terminal electrode of a sealing structure (first sealing structure) (see FIG. 2) that can be provided outside the exterior through at least the opening of the exterior. An electrical connection can be provided between the electrode and either the positive or negative electrode layer of the electrode assembly.
In addition, the tab can be in electrical contact with a metal portion of a further sealing structure (second sealing structure) (see FIG. 7) that can be provided inside the outer package, and the metal portion and the electrode can be electrically connected to each other. It can provide electrical connection between the electrode layers of either the positive or negative electrode of the assembly.
Also, there may be a tab (or lead) that can protrude or extend from the other of the positive electrode and the negative electrode of the electrode assembly, and the tab (or lead) is, for example, an outer body, particularly a metal cup-shaped member. It may be electrically connected.
Such tabs (or leads) may extend from or be part of the "current collectors" described above (i.e., "positive current collectors" and "negative current collectors"). may extend so as to protrude, and may be integrally made of the same material as the current collector.

In the present disclosure, the above configuration may be changed or modified as appropriate.

[Characteristics of the secondary battery of the present disclosure]
A secondary battery according to an embodiment of the present invention, for example, as illustrated in FIGS. has an exterior body 20 that can be accommodated together with the non-aqueous electrolyte.
For example, the exterior body 20 has an opening 21, and the sealing structure 30 is positioned so as to close the opening 21 (see FIG. 2).
In the present disclosure, the sealing structure 30 is also referred to as the "first sealing structure" or the "outer sealing structure", meaning, for example, the component, configuration or structure 30 enclosed by the dashed line in FIG. .

The sealing structure 30 is composed of a terminal portion 40 and a first sealing portion 50 . As illustrated in FIG. 2, the terminal portion 40 and the first sealing portion 50 may be provided so as to be stacked on each other. For example, the first sealing portion 50 is in contact with one main surface of the terminal portion 40 (for example, the lower main surface shown in FIG. 2), which corresponds to the peripheral edge portion or the outer portion of the terminal portion 40 . The portion 40 and the first sealing portion 50 may be arranged relative to each other.

The terminal portion 40 has a further sealing portion (second sealing portion) 41 and a terminal electrode 42 provided on the second sealing portion 41 . The term “terminal electrode provided in the second sealing portion” as used herein means, for example, a terminal electrode (for example, a plane visual contour) is included. In a preferred embodiment, the area occupied by the second sealing portion 41 is larger than the area occupied by the terminal electrode 42 in plan view of the terminal portion because of the "terminal electrode provided in the second sealing portion." there is As illustrated in FIG. 2, the sealing portion (second sealing portion) 41, which is an element included in the terminal portion 40, may be provided flush with the terminal electrode 42, for example. More specifically, the sealing portion (second sealing portion) 41 may be provided, for example, so as to surround the terminal electrode 42 and be in contact with the side surface of the terminal electrode 42 . From another point of view, the first sealing portion 50 is an element separate from the terminal portion 40, and is at a different height level (vertical level in the drawing) from the terminal electrode 42 of the terminal portion 40. While it may be positioned, the second sealing portion 41 is an element of the terminal portion 40 and may be positioned at the same height level as the terminal electrode 42 of the terminal portion 40 .

The first sealing portion 50 preferably comprises an inorganic sealing material. For example, as shown in FIG. 2, such an inorganic sealing portion 50 is interposed between the second sealing portion 41 of the terminal portion 40 and the exterior body 20, preferably the lid-like member 20a. may be provided or positioned in the
The fact that the first sealing portion 50 is “interposed” between the second sealing portion 41 and the exterior body 20 means that the second sealing portion 41 of the terminal portion 40 is separated from the second sealing portion 41 by the first sealing portion 50 . (preferably the ceramic member 41 containing ceramics) and the exterior body 20 (preferably the lid-like member 20a) are connected to each other. In the present disclosure, there is no particular limitation on the position where the first sealing portion 50 is arranged.

In the present disclosure, a secondary battery including such a first sealing structure 30 is called a secondary battery according to the "first embodiment" (see FIG. 2). In other words, a secondary battery including a single sealing structure corresponds to the secondary battery according to the first embodiment.

In the first embodiment, such a first sealing structure 30 can provide a secondary battery that exhibits improved airtightness, and in particular, can further improve the performance of preventing permeation of moisture such as water vapor. As a result, it becomes easier to improve the long-term reliability of the secondary battery, and the warranty period can be further extended.

In the secondary battery of the present invention, a further sealing structure 60 may be further provided inside the exterior body 20 to have a "double sealing structure" (see FIG. 7). In the present disclosure, such an additional sealing structure 60 is also referred to as a "second sealing structure" or an "internal sealing structure", such as the parts, configurations, and components enclosed in dashed lines in the lower portion of FIG. Or it means the structure 60.
The second sealing structure 60 has, for example, a metal portion 61 and a joint portion 62 . The coupling portion 62 may be a member for coupling the metal portion 61 and the exterior body 20, and is preferably coupled to the inner surface of the exterior body 20 (see FIG. 7).

In the present disclosure, a secondary battery including such a second sealing structure 60 is called a secondary battery according to the "second embodiment." In other words, two sealing structures (preferably two sealing structures arranged to face each other across the opening of the exterior body, that is, an external sealing structure and an internal sealing structure) The provided secondary battery corresponds to the secondary battery according to the second embodiment.

In the second embodiment, the second sealing structure 60 positioned inside the exterior body (in particular, the inner surface or the inner surface of the exterior body) exhibits even more improved airtightness, especially the permeation prevention property of volatilized electrolytic solution. It is possible to provide a secondary battery capable of further enhancing the above.

The secondary batteries according to the first embodiment and the second embodiment of the present disclosure will be described in detail below.

(First embodiment)
The secondary battery according to the first embodiment of the present disclosure basically comprises an electrode assembly 10 and an exterior body, preferably a lid, capable of housing the electrode assembly 10, as shown in FIGS. 1 and 2, for example. It has an outer body 20 which can be composed of a shaped member 20a and a cup shaped member 20b.
The exterior body 20 , preferably the lid-like member 20 a may have an opening 21 . In the first embodiment, a sealing structure 30 may be provided or positioned so as to block such an opening 21 . The sealing structure 30 may cover the opening 21 from above, as shown in FIGS. 1 and 2, or may be arranged in the exterior body, or may be arranged substantially flush with the exterior body. may In these cases, the first sealing portion 50 of the sealing structure 30 may be interposed between the second sealing portion 41 and the exterior body 20 . In other words, the first sealing portion 50 may couple the second sealing portion 41 of the terminal portion 40 and the exterior body 20 to each other.

(sealing structure)
In the present disclosure, the term “sealing structure” means a structure for closing an opening of an exterior body of a secondary battery, such as an opening that may be provided in a lid-like member of the exterior body.
For example, as shown in FIG. 2, the “sealing structure” is denoted by reference numeral “30”, and is a structure capable of closing the opening 21 of the exterior body 20 as a separate member from the exterior body 20, for example. (hereinafter also referred to as "first sealing structure" or "external sealing structure"). Such a first sealing structure makes it easier to prevent water such as water vapor from entering the secondary battery. Furthermore, such a first sealing structure makes it easier to prevent, for example, volatilized electrolytic solution from being released to the outside of the secondary battery. As a result, the airtightness reliability of the secondary battery is likely to be improved, and the product life of the secondary battery is likely to be maintained longer.

The sealing structure 30 may be composed of two or more members, and is composed of, for example, a terminal portion 40 and a first sealing portion 50 as shown in FIG. Preferably, it is composed of a terminal portion 40 composed of a terminal electrode 42 and a sealing portion 41 surrounding it, and a sealing portion 50 separate from the terminal portion 40 .

The first sealing portion 50 may comprise, for example, an inorganic sealing material, as will be described in detail below. That is, the first encapsulant 50 may be an inorganic encapsulant or an inorganic encapsulant. For example, the first sealing portion 50 contains at least one selected from the group consisting of metals, alloys and glass. The first sealing portion 50 may be provided between the terminal portion 40 and the exterior body 20 . More specifically, the first sealing portion 50 is provided or positioned so as to be interposed between the second sealing portion 41 of the terminal portion 40 and the exterior body 20 (for example, the lid-like member 20a). It's okay. The first sealing portion 50 makes it easier to prevent moisture from entering the interior of the secondary battery. Furthermore, the first sealing portion 50 makes it easier to prevent, for example, volatilized electrolytic solution from being discharged to the outside of the secondary battery. As a result, the airtightness reliability of the secondary battery is likely to be improved, and the product life of the secondary battery is likely to be maintained longer.

The terminal portion 40 has a second sealing portion 41 (which may be, for example, a second sealing portion containing ceramics) and a terminal electrode 42 .
At least part of the terminal electrode 42 may be provided inside the second sealing portion 41 . At least part of the terminal electrode 42 is exposed to the outside or outside of the secondary battery 101 at the terminal portion 40 . At least part of the terminal electrode 42 is exposed toward the inside or the inside of the secondary battery 101 at the terminal portion 40 . Preferably, the terminal electrode 42 is exposed on one main surface of the terminal portion 40 and also exposed on the other main surface of the terminal portion 40 . In a more specific aspect, the terminal electrode 42 is preferably exposed on the outer main surface of the terminal portion 40 and also exposed on the inner main surface of the terminal portion 40 .
By exposing at least part of the terminal electrode 42 to the outside or outside of the secondary battery 101, an electrical contact with other external equipment can be formed. At least part of the terminal electrode 42 is exposed toward the inside or inside of the secondary battery 101, so that the electrode assembly 10 can be attached to the electrode assembly 10 via a tab (for example, the tab 11 (first tab) shown in FIG. 2). It can be electrically connected to either one of the positive electrode and the negative electrode. The other of the positive and negative electrodes of the electrode assembly 10 is electrically connected to the exterior body 20 (preferably the cup-shaped member 20b) via a tab (for example, another tab 12 (second tab) shown in FIG. 2). It can be.

A tab (eg, tab 11 and/or tab 12) in the present disclosure may be a member comprising metal, preferably a metal member having an elongated shape. The tabs may be flexible and may be provided in a flexed and/or bent configuration. For example, the tab may consist of the electrode current collector of the electrode assembly, or it may be a current collecting lead provided on the electrode assembly (particularly its electrode). When the tab is made of an electrode current collector, the tab may be made of a metal portion of the electrode current collector that is not provided with the electrode material. When the tab consists of a current collecting lead, the tab may consist of a metal member having a thin-walled configuration and/or an elongated configuration. By way of example only, tab 11 may be electrically connected to the positive electrode of electrode assembly 10 . In such a case, the terminal electrode 42 can function as a positive electrode terminal of the secondary battery. Tab 11 may be made of aluminum, for example. Also by way of example only, the other tab 12 may be electrically connected to the negative electrode of the electrode assembly 10 . In such a case, the exterior body 20 (preferably the cup-shaped member 20b) can function as a negative electrode terminal of the secondary battery. Such a battery configuration is preferable in that a larger negative electrode terminal can be provided when the positive electrode and the negative electrode have layers capable of intercalating and deintercalating lithium ions.

The terms "terminal portion" and "first sealing portion" used in the present disclosure will be described in detail below.

(Terminal part)
In the present disclosure, the term “terminal portion” means a member that can function as a terminal by being electrically connected to an external element such as another device outside the secondary battery.
For example, as shown in FIG. and In the terminal portion 40, the sealing portion 41 and the terminal electrode 42 may be integrated with each other, preferably they may be integrated with each other so that the terminal portion forms a single member or single component.

The shape of the terminal portion is not particularly limited, and may be plate-like. That is, the mutual combination of the sealing portion 41 and the terminal electrode 42 may have a plate shape or a flat shape as a whole. In the present disclosure, "plate-like" means a shape having at least two major surfaces, which are positioned in a parallel or substantially parallel relationship to each other. The planar shape of the terminals is also not particularly limited, and may be, for example, rectangular, circular, and/or any other geometric shape.

The overall thickness of the terminal portion is not particularly limited. For example, the thickness of the entire terminal portion may be 0.1 mm or more and 1.5 mm or less.

In the present disclosure, the “second sealing portion” preferably refers to a sealing portion that constitutes the terminal portion as a component of the terminal portion itself, rather than a sealing portion that is interposed between the terminal portion and the exterior body. at least mean. Such a second sealing portion preferably has insulating properties, and preferably can hold or fix at least a portion of the terminal electrode inside or inside thereof. In addition, the second sealing portion can preferably prevent the infiltration of water such as water vapor into the battery and/or the release of volatilized chemical components such as electrolyte and electrolytic solution from the battery. Moreover, this second sealing portion can preferably prevent deformation, warping and/or bulging of the entire terminal portion.

For example, as shown in FIG. 2, the “second sealing portion” is denoted by reference numeral “41”, the second sealing portion 41 is provided with a terminal electrode 42, and at least part of the terminal electrode 42 is Preferably, it is held or secured to the second sealing portion 41 . As illustrated, the sealing portion 41 and the terminal electrode 42 are provided so that the sealing portion 41 and the terminal electrode 42 are adjacent to or in direct contact with each other so that the sealing portion 41 surrounds the terminal electrode 42 . It's okay. For example, the terminal portion 40 may have a form in which the terminal electrode 42 occupies a portion of the sealing portion region formed by the sealing portion 41 .

"Insulation" of the "second sealing portion" preferably means electrical insulation relative to the terminal electrode. In other words, preferably no electrical connection is made to the terminal electrode, or almost no electrical connection is made. For example, the second sealing portion can be made of an electrically insulating material such as resin and/or ceramics.

The second sealing portion may be made of, for example, a non-resin material, and in such a case, the second sealing portion can be referred to as a non-resin sealing portion. In this regard, the second sealing portion may comprise "ceramics". When the second sealing portion contains ceramics, it becomes easier to prevent water such as water vapor from entering the inside of the secondary battery more remarkably than materials such as resin. Furthermore, since ceramics are superior in corrosiveness to water such as water vapor and/or chemicals, it becomes easier to prevent permeation and/or release of volatilized electrolytic solution to the outside of the secondary battery, for example. As a result, the reliability of the airtightness of the secondary battery can be improved more easily, and the product life of the secondary battery can be easily maintained for a longer period of time.

In the present disclosure, "ceramics" is not particularly limited as long as it is, for example, ceramic crystals, especially metal oxides. For example, ceramics include lithium (Li), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), yttrium (Y), zirconium (Zr), Titanium (Ti), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu), Zinc (Zn), Boron (B), Aluminum (Al), Silicon (Si), Indium (In), Tin (Sn), Antimony (Sb), Barium (Ba), Tantalum (Ta), Tungsten (W), Lead (Pb), Bismuth (Bi), Lanthanum (La), Cesium (Ce), Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Oxygen (O), Carbon (C), It may be composed of at least one element selected from the group consisting of nitrogen (N), sulfur (S), phosphorus (P), fluorine (F) and chlorine (Cl). As just one example, the ceramics may be, for example, alumina (aluminum oxide). As typified by the second sealing portion made of or composed of ceramics, the second sealing portion 41 can also be referred to as an inorganic sealing portion or an inorganic sealing portion.

In the present disclosure, a "terminal electrode" means a portion or member that can be electrically connected (preferably directly connected) to an external element such as another device outside the secondary battery.

For example, as shown in FIG. 2, the "terminal electrode" is a member indicated by reference numeral "42", at least part of which may be provided in the second sealing portion 41 and held or fixed.

The terminal electrode preferably has conductivity. The terminal electrodes may be made of metals and/or alloys, for example. Terminal electrodes are made of, for example, gold (Au), silver (Ag), copper (Cu), iron (Fe), aluminum (Al), chromium (Cr), titanium (Ti), nickel (Ni), palladium (Pd). and platinum (Pt). Although this is just one example, the terminal electrode is made of, for example, a single metal.

The terminal electrode may be integrally formed as the terminal part together with the second sealing part using a technique such as firing. Alternatively, the terminal electrodes may be formed using techniques such as a printing method, a coating method, a plating method, a method using a conductive paste, a vapor deposition method, and/or a sputtering method.

For example, as shown in FIG. 2, the terminal electrode 42 may extend between both main surfaces of the terminal portion 40 . Preferably, the terminal electrode 42 may extend between both main surfaces of the terminal portion 40 so as to penetrate the terminal portion 40 (see FIGS. 2 and 4). That is, the terminal electrode 42 may extend in the thickness direction of the terminal portion 40 so as to be exposed on both one and the other of the opposing main surfaces of the terminal portion 40 . With such a configuration, the outer main surface of the terminal portion 40, in other words, the main surface opposite to the main surface directly facing the secondary battery (particularly its electrode assembly), that is, the illustrated terminal electrode 42 While the upper surface can be in electrical contact with external elements such as other equipment, the inner main surface of the terminal portion 40, in other words, the main surface directly facing the secondary battery (especially its electrode assembly), that is, the illustrated The lower surface of the terminal electrode 42 to be connected may be in electrical contact with the tab 11 .

The terminal electrode 42 may extend between the two main surfaces so that the width dimension of the terminal electrode 42 is constant (see FIGS. 2 and 4 (A)). )reference). Alternatively, the terminal electrode may extend between both main surfaces of the terminal portion so that the width dimension of the terminal electrode 42 is non-uniform. When the terminal electrodes extend between the main surfaces so as to be non-constant, the terminal electrodes may extend so that the width dimension changes gradually, or the terminal electrodes extend so that the width dimension varies stepwise. (see FIG. 7 and FIGS. 4(B)-4(G)).

From another point of view, the terminal electrodes 42 may be arranged on both main surfaces of the terminal portion 40 so as to extend relatively large in the surface direction or be wide (for example, FIG. 4(G)). terminal electrode 42''). For example, the terminal electrode portions positioned on both major surfaces of the terminal portion 40 may be wider or broader than the terminal electrode portion inside the terminal portion. In such a case, the relatively wide or broad terminal electrode portion can form a more suitable electrode surface (for example, two suitable electrode surfaces facing each other on both main surfaces of the terminal portion are provided). obtain).

When the overall airtightness of the terminal portion 40 is emphasized, if the ratio of the terminal electrode 42 to the second sealing portion 41 is smaller than that of the second sealing portion 41 in the same terminal portion volume, the volume of the second sealing portion 41 is reduced. is preferable because it increases On the other hand, when more emphasis is placed on electrical connection with an external element such as another device, the ratio of the terminal electrode 42 to the second sealing portion 41 on the outer (upper) main surface of the terminal portion 40 is the area standard. , it is preferable because the contact area with the external element increases. On the inner (lower) main surface of the terminal portion 40, the ratio of the terminal electrode 42 to the second sealing portion 41 may be smaller on an area basis from the viewpoint of airtightness (see FIG. 4B).

The ratio (for example, area ratio) of the terminal electrode 42 to the second sealing portion 41 on the outer (upper) main surface of the terminal portion 40 is the same as that of the second sealing portion on the inner (lower) main surface of the terminal portion 40. It may be larger than the ratio of the terminal electrode 42 to 41 . In other words, the ratio of the terminal electrode 42 to the second sealing portion 41 on the inner (lower) main surface of the terminal portion 40 is the ratio of the second sealing portion 41 on the outer (upper) main surface of the terminal portion 40 to It may be smaller than the proportion of the terminal electrode 42 (see FIG. 4B).

With such a configuration, the contact area with external elements is increased on the outer (upper) main surface of the terminal portion 40 , while the inner (lower) main surface of the terminal portion 40 is in electrical contact with the tab 11 more reliably. The second sealing portion 41 facilitates further improvement of the airtightness.
A portion of the inner (lower) main surface of the terminal portion 40 that can be electrically contacted with the tab 11 may be formed as a “narrow portion” (see FIG. 4B). The “narrow portion” may be separately formed as a “conducting path” inside the second sealing portion 41 .

The terminal section 40 may have a multi-layer structure (or multi-layer structure). For example, the terminal portion 40 may consist of two or more layers (see FIG. 4). Both the second sealing portion 41 and the terminal electrode 42 that may be included in the terminal portion 40 may have a multilayer structure or a multi-layer structure. Alternatively, only the second sealing portion 41 that may be included in the terminal portion 40 may have two or more layers, or only the terminal electrode 42 that may be included in the terminal portion 40 may have two or more layers. It's okay.

For example, a terminal portion 40a shown in FIG. 4A corresponds to the terminal portion 40 shown in FIG. A part of the terminal electrode 42 is formed in layers on the outer (upper) main surface of the terminal portion 40a shown in FIG. Part of the portion 41 may be formed in layers to form a multilayer structure. For example, the terminal portion 40b in FIG. 4B may be multilayered with the second sealing portion 41' and the terminal electrode 42'.

For example, one or more layered members 43 (for example, a layer of a material different from that of the second sealing portion 41′) are provided inside the second sealing portion 41′ like the terminal portion 40c shown in FIG. 4C. The terminal portion 40c may be multi-layered by providing . At this time, it can also be considered that the second sealing portion 41 ′ is vertically divided and multi-layered together with the layered member 43 .

The layered member 43 may be, for example, a layered member that can be provided to prevent permeation of moisture such as water vapor and/or permeation of volatilized electrolytic solution, particularly vertical permeation. Preferably, layered member 43 is a metal layer.

A layered member such as a metal layer in the terminal portion 40 may not be used for electrical connection. Such a layered member such as a metal layer in a non-electrically connected state is present in the second sealing portion, for example, in the lateral direction, thereby preventing permeation of moisture such as water vapor and/or permeation of volatilized electrolytic solution, In particular, it can contribute to prevention of transmission in the vertical direction.

There are no particular restrictions on the number and positions of the layered members arranged inside the second sealing portion.

For example, a plurality of

layered members

44a and 44b may be provided under the second sealing portion 41' (for example, a portion corresponding to the lower half thickness) of the terminal portion 40d shown in FIG. 4(D).
The layered member 44a may be, for example, a layered member that can be mainly provided for preventing permeation of volatilized electrolytic solution, and is preferably a metal layer.
The layered member 44b may be, for example, a layered member that can be mainly provided to prevent permeation of volatilized electrolytic solution and/or moisture such as water vapor from the outside, and is preferably a metal layer.

For example,

layer members

45a and 45b may be provided inside the second sealing portion 41' like the terminal portion 40e shown in FIG. 4(E).
The

layered members

45a and 45b are arranged with a gap therebetween in the vertical direction when viewed in cross section. Since the

layered members

45a and 45b are provided so as to integrally cross the inside of the second sealing portion 41' in the left-right direction, moisture such as water vapor and/or volatilized electrolytic solution cannot permeate. etc. can be prevented.

Layered members

45a and 45b may be metal layers.

For example,

layered members

46a, 46b, and 46c may be provided in the lower, intermediate, and upper portions of the second sealing portion 41', respectively, like the terminal portion 40f shown in FIG. 4(F).
The layered member 46a may be, for example, a layered member that can be provided mainly for preventing permeation of volatilized electrolytic solution, and is preferably a metal layer.
The layered member 46b may be, for example, a layered member that can be mainly provided to prevent permeation of volatilized electrolytic solution and/or moisture such as water vapor from the outside, and is preferably a metal layer.
The layered member 46c may be, for example, a layered member that can be mainly provided for preventing permeation of moisture such as water vapor from the outside, and is preferably a metal layer.

In the present disclosure, additional layered members may be added inside and/or on the surface of the terminal portion.

The layered member (preferably a metal layer) may or may not be responsible for electrical connection between the upper and lower main surfaces of the terminal portion. When not responsible for electrical connection between the upper and lower main surfaces of the terminal portion, the layered member may be, for example, a non-electrically connected metal layer provided in the inner region of the second sealing portion. On the other hand, when performing electrical connection between the upper and lower main surfaces of the terminal portion, the layered member may be a metal layer for electro-liquid connection provided in the inner region of the second sealing portion. In this case, the layered member may be electrically connected to the terminal electrode.

As in the preferred embodiment shown in FIG. 4, the layered member corresponds to a dummy electrode layer that does not provide electrical connection between the upper and lower main surfaces of the terminal portion. Alternatively, the layered member may be a ground layer.
That is, the layered member may be, for example, a metal layer provided exclusively for preventing permeation of moisture such as water vapor and/or volatilized electrolytic solution. If more emphasis is placed on enhancing such an effect, the metal layer may be provided as a plurality of layers of at least two or more in the second sealing portion.

When the layered member is provided, the layered member may be arranged so that the second sealing portion has a meandering shape, that is, the permeation path of moisture such as water vapor and/or volatilized electrolytic solution becomes a detour. . In other words, vertical infiltration of moisture such as water vapor and/or volatilized electrolytic solution may be prevented by the “meandering/circumferential form provided by the arrangement of the plurality of layered members”. Layered members may be connected vertically as desired to form more complex serpentine and/or circuitous shapes.

The second sealing portion may be one in which the layered member occupies 95% or more of the area as a whole when viewed from above. With such an area ratio, for example, it is possible to more effectively prevent water such as water vapor and/or volatilized electrolytic solution from penetrating vertically in a cross-sectional view.

The metal elements forming the layered member, preferably the metal layer, are not particularly limited, and examples include gold (Au), silver (Ag), copper (Cu), iron (Fe), aluminum (Al), chromium (Cr), It may be at least one selected from the group consisting of titanium (Ti), nickel (Ni), palladium (Pd) and platinum (Pt). The metal layer may be composed of a single metal, or may be composed of an alloy.

When the layered member is a metal layer, for example, it is possible to prevent permeation of moisture such as water vapor and/or volatilized electrolytic solution, and to easily impart higher strength to the terminal portion, which is sufficient for the internal pressure increase of the secondary battery. easier to tolerate.

The layered member may or may not be made of the same material as the terminal electrode.

The layered member (preferably a metal layer) may preferably be formed integrally with the ceramics and terminal electrodes contained in the second sealing portion through a technique such as firing when forming the second sealing portion. Alternatively, a layered member (preferably a metal layer) may be formed using techniques such as printing, coating, plating, using a conductive paste, vapor deposition, and/or sputtering.

In the terminal portion 40g shown in FIG. 4G, similarly to the terminal electrode 42' shown in FIG. A layered member may be arbitrarily provided in the second sealing portion 41″ shown in FIG. 4(G) as well.

In the present disclosure, the terminal portion may further have a "conductor", and this conductor may be connected to the terminal electrode. The material of the conductor is not particularly limited as long as it is an electrically conductive substance and/or material (an example is copper, but is not necessarily limited thereto), and its shape is not particularly limited. Conductors may be, for example, "vias" such as may be used in electronic substrates. That is, the conductor included in the terminal portion may have a via configuration. The form of the via is not particularly limited, and may have a through hole, for example. In other words, a via having a through hole or the like may be arranged or formed to penetrate the terminal electrode. For example, at least part of the terminal electrodes 42' and 42'' shown in FIGS. 4B and 4G may be provided as conductors in the form of vias. More specifically, the terminal electrodes At least relatively narrow portions in 42', 42'' may be provided as conductors, for example in the form of vias.

(First sealing portion)
In the present disclosure, the “first sealing portion” means, for example, a member that can be provided to prevent permeation of moisture such as water vapor and/or volatilized electrolytic solution. For example, the first encapsulant may include an inorganic encapsulant. The first sealing portion is provided or positioned between the second sealing portion that may be included in the terminal portion and the exterior body, and the second sealing portion and the exterior body are mutually connected. can be combined. That is, the first sealing portion is interposed between the terminal portion and the exterior body, and is located on the surface of the exterior body (on the outer surface of the exterior body) corresponding to the area around the opening of the exterior body through which the tab passes. is provided in
For example, as shown in FIG. 2, the first sealing portion is indicated by reference numeral "50", and is between the second sealing portion 41 and the outer surface of the exterior body 20 (preferably the lid-like member 20a). You can intervene.

There is no particular limitation on the thickness of the first sealing portion. For example, the thickness of the first sealing portion may be 0.03 mm or more and 0.3 mm or less.

In the present disclosure, the term "inorganic encapsulant" means an inorganic material that does not contain organic materials, or that inorganic materials are relatively more abundant than organic materials on a volume and/or weight basis. Means a lot of material.

In the present disclosure, the first sealing portion is essentially different from conventional seal members that can be manufactured from resin or the like (see resin seal member 140 shown in FIG. 11). In short, the first sealing portion can be called a non-resin sealing portion because it is made of a non-resin material. For example, the first sealing portion contains at least one selected from the group consisting of metals, alloys and glass.

Examples of “metals” that can be included in the first sealing portion in the present disclosure include tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), cadmium (Cd), copper (Cu), Gold (Au), Indium (In), Silver (Ag), Aluminum (Al), Arsenic (As), Iron (Fe), Chromium (Cr), Nickel (Ni), Cobalt (Co), Zinc (Zn), At least one metal selected from the group consisting of germanium (Ge), phosphorus (P), gallium (Ga), silicon (Si) and manganese (Mn) can be mentioned. By including the metal in the first sealing portion, it becomes easier to improve the reliability of airtightness.

In the present disclosure, the "alloy" that can be included in the first sealing portion includes a component comprising at least two metals selected from the above metals. By including the alloy in the first sealing portion, it becomes easier to improve the reliability of airtightness. In addition, since the first sealing portion contains an alloy, it becomes easier to connect the second sealing portion and the exterior body. As an alloy, for example, Kovar containing at least iron, nickel and cobalt may be used. This is because Kovar has a low coefficient of thermal expansion and facilitates bonding of the second sealing portion, especially the second sealing portion containing ceramics, and the exterior body at around room temperature.

Examples of "glass" that can be included in the first sealing portion in the present disclosure include soda lime glass, potash glass, borate glass, borosilicate glass, barium borosilicate glass, zinc borate glass, selected from the group consisting of barium borate glass, bismuth borosilicate glass, bismuth zinc borate glass, bismuth silicate glass, phosphate glass, aluminophosphate glass and zinc phosphate glass At least one type can be mentioned. By including glass in the first sealing portion, it becomes easier to improve the reliability of airtightness. In addition, since the first sealing portion contains glass, it becomes easier to connect the second sealing portion and the exterior body to each other.

As described above, the second sealing portion according to a preferred embodiment is also a non-resin sealing portion made of a non-resin material. Both the (first sealing portion) and the second sealing portion of the terminal portion can be non-resin sealing portions. That is, the encapsulation structure is provided with double non-resin encapsulation portions. The term "non-resin material" used herein means a material other than a resin material, and refers to, for example, at least one selected from the group consisting of ceramics, metals, alloys and glass described above. When both the sealing portion (first sealing portion) and the second sealing portion of the terminal portion in the sealing structure are non-resin sealing portions, for example, permeation and/or secondary It becomes easier to prevent release to the outside of the battery more remarkably, and as a result, it becomes easier to further improve the reliability of the airtightness of the secondary battery. That is, the product life of the secondary battery can be easily maintained even longer.

The first sealing part can be coupled with the second sealing part and the outer body by, for example, welding (eg, resistance welding), soldering (eg, AuSn, etc.), and/or heating. In other words, in the present disclosure, the second sealing portion and the exterior body can be coupled to each other via the first sealing portion. More specifically, it is possible to couple the second sealing portion of the terminal portion and the exterior body to each other through the first sealing portion such that the terminal portion closes the opening of the exterior body. can.

By using the first sealing portion in the present disclosure, for example, it becomes easier to significantly prevent permeation of moisture such as water vapor and / or volatilized electrolytic solution, and the second sealing portion and the exterior body are easily combined with each other. In particular, the second sealing portion made of ceramics and the exterior body made of metal are more easily and preferably combined.

In the present disclosure, the first sealing portion preferably contains an inorganic sealing material, so that it is more excellent in bonding with the second sealing portion similarly containing inorganic ceramics. . In such a case, it can be said that the first sealing portion is the inorganic sealing portion and the second sealing portion of the terminal portion is also the inorganic sealing portion.

Such a first sealing portion significantly prevents permeation of moisture such as water vapor and/or volatilized electrolytic solution, compared to a conventional resin-made sealing member (see FIG. 11). easy.

FIG. 2 specifically shows an example of the secondary battery 101 according to the first embodiment of the present disclosure. A secondary battery 101 includes an electrode assembly 10 and an exterior body 20 capable of accommodating the electrode assembly 10 and an electrolyte or electrolytic solution. The exterior body 20 may be a metal exterior body, and may be composed of a lid-shaped member 20a and a cup-shaped member 20b. The lid-shaped member 20a and the cup-shaped member 20b of the metal sheath may be joined together using a technique such as welding, for example.

The lid-shaped member 20a may be provided with a step S for placing the sealing structure 30 (particularly, the sealing structure provided outside the exterior body). The exterior body opening installation surface on which the opening is provided in the exterior body has a step around the opening (that is, the wall portion that provides a relatively different height level or position level is the exterior body). It can be said that it is provided in For example, the central region of the exterior body opening mounting surface may be at a relatively lower height or position level than the outer regions thereof, and thus the central region of the exterior body opening mounting surface may be recessed. In the illustrated embodiment, the highest surface of the first sealing structure 30 is positioned higher than the highest surface of the lid-like member 20a. However, depending on the specifications of the secondary battery 101, these heights may be flush with each other, or the height of the first sealing structure 30 may be lower than the height of the lid-like member 20a. may

The exterior body 20 (for example, the lid-shaped member 20a) has an opening 21, and the first sealing structure 30 is provided so as to close the opening 21. As shown in FIG. In a preferred aspect, a first sealing portion provided on the surface of the exterior body corresponding to the peripheral region of the opening of the exterior body (on the outer surface of the exterior body) is interposed between the exterior body and the terminal portion. The first sealing structure 30 is arranged such that the terminal portion closes the opening of the exterior body.
There is no particular limitation on the shape of the opening 21 of the exterior. The shape of the opening 21 of the exterior may be, for example, circular, elliptical, square or rectangular in plan view, or any other geometric shape.

A space provided inside the exterior body 20 (for example, the cup-shaped member 20b) may house the electrode assembly 10 together with an electrolyte (for example, a non-aqueous electrolyte solution).
The electrode assembly 10 provided inside the outer package 20 has an electrode configuration layer 5 including a positive electrode 1, a negative electrode 2, and a separator 3, as shown in FIG. 1, for example. For example, the wound laminated electrode assembly 10 shown in FIG. 1(B) may be used. Although there is no particular limitation, the cross section shown in FIG. may be placed (not shown).

As shown separately by the portion surrounded by the dashed line in FIG. The sealing structure 30 can close the opening 21 provided in the exterior body 20 (for example, the lid-like member 20a).

The terminal portion 40 has a second sealing portion 41 and a terminal electrode 42 provided on the second sealing portion 41 . The terminal electrode 42 may extend directly or indirectly between the upper and lower main surfaces of the second sealing portion 41 . A portion of the terminal electrode 42 may be exposed on the upper main surface and the lower main surface of the terminal portion 40, and these exposed portions can contribute to electrical connection.
Terminal electrode 42 can be physically and electrically connected to first tab 11 that can extend from either the positive or negative electrode of electrode assembly 10 . Also, the second tab 12 that can extend from the other of the positive and negative electrodes of the electrode assembly 10 can be physically and electrically connected to the exterior body 20, preferably the cup-shaped member 20b.
Terminal electrode 42 and first tab 11 may be electrically connected to the positive electrode of electrode assembly 10 . In this case, the terminal electrode 42 can function as a positive terminal. The outer body 20 , preferably the cup-shaped member 20 b and the second tab 12 may be electrically connected to the negative electrode of the electrode assembly 10 . In this case, the exterior body 20 can function as a negative terminal.

The first sealing portion 50 preferably contains an inorganic sealing material, and the second sealing portion 41 included in the terminal portion 40 and the exterior body 20 (preferably the lid-shaped member 20a) is interposed between The first sealing part 50 is preferably arranged around the opening 21 provided in the exterior body, and may have an opening of the same shape as the opening 21 of the exterior body. That is, the first sealing portion 50 has a shape along the peripheral edge of the terminal portion 40 as a whole, but has an opening (for example, the same or similar shape as the opening of the outer package) in the inner region thereof. opening).

The second sealing portion 41 included in the terminal portion 40 may be made of ceramics, for example. When the second sealing portion 41 is made of ceramics, it becomes easy to physically support and/or fix the terminal electrode 42 and to provide insulation to the terminal electrode 42 .

In the secondary battery 101, among the components or members that can constitute the first sealing structure 30, the second sealing portion 41 and the first sealing portion 50 are preferably non-resin sealing portions. . In other words, it can be said that a single encapsulation structure has double non-resin encapsulations, and in a preferred embodiment, double inorganic encapsulations. The non-resin-sealed portion of the first sealing portion 50 and the non-resin-sealed portion of the sealing portion 41 (second sealing portion) of the terminal portion 40 may have the same material. It may have different materials. In a preferred embodiment, the non-resin-sealed portion of the first sealing portion 50 and the non-resin-sealed portion of the sealing portion 41 (second sealing portion) of the terminal portion 40 have different materials. For example, the first sealing portion 50 may comprise a non-ceramic material such as a metal and/or alloy, while the sealing portion 41 of the terminal portion 40 may comprise a ceramic material. As described above, the second sealing portion 41 and the first sealing portion 50 can preferably each contain an inorganic sealing material, so that the sealing performance can be improved as compared with a conventional resin sealing member. easy to provide. Specifically, remarkably improved water vapor permeation prevention properties (more specifically, water vapor permeation prevention properties) and/or volatilized electrolytic solution permeation prevention properties are likely to be exhibited.
In addition, the second sealing portion 41 and the exterior body 20 (preferably the lid-shaped member 20a) can be more easily and firmly coupled by the first sealing portion 50, and further improved airtightness can be achieved. .

FIG. 3 shows a modification of the secondary battery according to the first embodiment of the present disclosure. The configuration of the secondary battery 102 shown in FIG. 3 is the same as the configuration shown in FIG. 2 except for the lid member 20a'.
The lid-shaped member 20a' shown in FIG. 3 has an opening 21' like the lid-shaped member 20a shown in FIG. It has become. Unlike the lid-like member 20a shown in FIG. 2, the lid-like member 20a' in FIG. 3 does not have a step (S) for providing the first sealing structure 30. As shown in FIG. It can be said that the lid-like member 20a' in FIG. 3 is made of a flat plate-like metal member as a whole.
Alternatively or additionally, the terminal portion 40 (see FIG. 2) of the first sealing structure 30 may be positioned within the opening 21' shown in FIG. The position of the first sealing portion 50 is not particularly limited as long as the second sealing portion 41 and the lid-like member 20a' are coupled via the stop portion 50. FIG.

In the secondary battery 102 shown in FIG. 3, since the surface of the lid member 20a' is flat, the space inside the battery can be used more effectively.

FIG. 4 schematically shows variations of the terminal portion 40 that can be employed in the embodiments of FIGS. 2 and 3. FIG.

FIG. 4A shows a terminal portion 40a similar to the terminal portion 40 used in FIGS.
In the terminal portion 40a, the area of the upper surface of the terminal electrode 42 and the area of the lower surface of the terminal electrode 42 are designed to be the same.

FIG. 4B shows a terminal portion 40b as a modified example of the terminal portion 40a shown in FIG. 4A.
In the terminal portion 40b, the area of the upper surface side of the terminal electrode 42' and the area of the lower surface side thereof are designed to be different from each other. It can be said that the exposed area of the terminal electrode on one main surface (upper surface) of the terminal portion is different from the exposed area of the terminal electrode on the other main surface (lower surface) of the terminal portion. In the exemplary embodiment shown in FIG. 4B, the area of the upper surface side of the terminal electrode 42' is larger than the area of the lower surface side. In other words, the area of the lower surface side of the terminal electrode 42' is smaller than the area of the upper surface side. Complementarily, the area of the upper surface side of the second sealing portion 41' is smaller than the area of the lower surface side. In other words, the area of the lower surface side of the second sealing portion 41' is larger than the area of the upper surface side.
The terminal electrode 42' and the second sealing portion 41' may be partially laminated on each other.
Moreover, each of the terminal electrode 42' and the second sealing portion 41' may be multi-layered. In that case, it is desirable that the terminal electrodes 42' are electrically connected in the vertical direction (that is, in the thickness direction of the terminal portion 40).

FIG. 4(C) shows a terminal portion 40c as a modified example of the terminal portion 40b shown in FIG. 4(B). In the terminal portion 40c, another member (for example, a member made of a material different from that of the second sealing portion, such as a metal member or a metal layer) crosses the inside of the second sealing portion 41'. is provided as follows. By configuring the terminal portion in this manner, the airtightness can be more easily improved. Expressed in another way, in the terminal portion 40c, a layered member (for example, a metal layer) 43 is arranged inside the second sealing portion 41' to form more layers.

FIG. 4(D) shows a terminal portion 40d as a modified example of the terminal portion 40b shown in FIG. 4(B). In the terminal portion 40d, another member (for example, a member made of a material different from that of the second sealing portion, such as a metal member or a metal layer) crosses the inside of the second sealing portion 41'. There are multiple Note that such a separate member (for example, a metal member or a metal layer) may not be electrically connected to the terminal electrode. In the terminal portion according to a preferred aspect, the metal layer provided inside the second sealing portion and not electrically connected to the terminal electrode extends in a direction perpendicular to the thickness direction of the terminal portion. are doing. By configuring the terminal portion in this manner, the airtightness can be more easily improved. This is because the metal material can effectively contribute to the anti-permeation property as a denser material. Expressed in another way, in the terminal portion 40d, a plurality of layered members (for example, metal layers) 44a and 44b are arranged inside the second sealing portion 41' to form more layers. As described above, the layered member does not have to be electrically connected to the terminal electrode. Airtightness can be further improved by increasing the number of layered members (for example, metal layers).

FIG. 4(E) shows a terminal portion 40e as a modified example of the terminal portion 40b shown in FIG. 4(B).
In the terminal portion 40e, a plurality of layered members (for example, metal layers) 45a and 45b are arranged inside the second sealing portion 41' to form a multilayer structure. Airtightness can be further improved by increasing the number of layered members (for example, metal layers).
As can be seen from the configuration of the terminal portion 40e, a plurality of separate members provided inside the second sealing portion 41' (that is, members made of a material different from the material of the second sealing portion described above, such as a metal member or metal layers, etc.) may be provided at different height levels or internal depth levels. For example, as shown in FIG. 4(E), one of two layered members that do not overlap each other in the thickness direction of the terminal portion is arranged relatively on the upper side, and the other is arranged relatively on the lower side. It can be.
In a preferred exemplary embodiment, the layered member (for example, metal layer) 45a is formed on the lower side of the second sealing portion 41' (for example, the region below the brim-shaped portion of the terminal electrode, preferably only the lower region). By arranging it in a limited area), for example, it becomes easier to suppress permeation of volatilized electrolytic solution. On the other hand, by arranging another layered member (for example, a metal layer) 45b above the second sealing portion 41' (preferably, a region outside the brim-shaped portion of the terminal electrode in the width direction), for example, It becomes easy to suppress permeation of water such as water vapor from the outside and/or permeation of electrolyte volatilized from the inside.

FIG. 4(F) shows a terminal portion 40f as a modified example of the terminal portion 40d shown in FIG. 4(D).
In the terminal portion 40f, a plurality of layered members (for example, metal layers) 46a, 46b and 46c are arranged inside the second sealing portion 41' to make the terminal portion 40f even more multilayered. Airtightness can be further improved by further increasing the number of layered members (for example, metal layers).
Specifically, the layered member (for example, a metal layer) 46a is placed below the second sealing portion 41' (for example, the region below the brim-shaped portion of the terminal electrode, preferably the region including the lower region). By arranging it in a wide area), for example, it becomes easier to suppress permeation of volatilized electrolytic solution. On the other hand, by arranging the layered member (for example, a metal layer) 46c on the upper portion of the second sealing portion 41' (preferably, the region outside the brim-shaped portion of the terminal electrode in the width direction), It becomes easier to suppress permeation of moisture such as water vapor.
Furthermore, by arbitrarily adding the layered member (for example, a metal layer) 46b, it becomes easier to suppress the permeation of moisture such as water vapor from the outside and/or the permeation of volatilized electrolytic solution.

There are no particular restrictions on the type of metal element that constitutes the metal layer. In a preferred embodiment, the metal layer is a layer made of at least one metal material selected from the group consisting of copper, aluminum, stainless steel, nickel, silver, gold, chromium, titanium, palladium, platinum, tin and iron. can be

FIG. 4(G) shows a terminal portion 40g as a modified example of the terminal portion 40b shown in FIG. 4(B). In the terminal portion 40g, the terminal electrode 42'' is multi-layered so as to have two similar upper and lower electrode surfaces. point-symmetrical or line-symmetrical cross-sectional shape). A layered member (preferably a metal layer) may be added to the terminal portion 40g in the same manner as described above.

In the terminal electrodes shown in FIG. 4, vias having through holes may be arbitrarily provided.

FIG. 5 shows variations in arrangement of the terminal electrodes 42 .
FIGS. 5A to 5F show, for example, a round (button-shaped or coin-shaped) secondary battery having an exterior body 20 which is circular in plan view. That is, in FIGS. 5(A) to 5(F), the exterior body 20 has a circular outline outside the plan view.
5A to 5F, the second sealing portion 41 has a rectangular shape in plan view (that is, a rectangular outline outside plan view). However, the second sealing portion 41 is not limited to this, and may have another shape such as a square or a circle in a plan view (that is, a square or a circle outline outside the plan view).
In FIGS. 5A to 5C, the terminal electrode 42 has a rectangular shape in plan view (that is, a rectangular outline outside plan view).
In FIG. 5A, the terminal electrode 42 is arranged at the geometric center of the second sealing portion 41 . The terminal electrode may be arranged offset from the geometric center of the second encapsulant (ie, arranged off-center). In FIG. 5B, the terminal electrode 42 is offset leftward from the geometric center of the second sealing portion 41 . In FIG. 5C, the terminal electrode 42 is offset rightward from the geometric center of the second sealing portion 41 .
5D to 5F, the terminal electrode 42 has a circular shape in plan view.
In FIG. 5D, the terminal electrode 42 is arranged at the geometric center of the second sealing portion 41 . Similarly, the terminal electrode may be offset from (ie, displaced from) the geometric center of the second encapsulant. In FIG. 5E, the terminal electrode 42 is offset leftward from the geometric center of the second sealing portion 41 . In FIG. 5F, the terminal electrode 42 is offset rightward from the geometric center of the second sealing portion 41 .
In the forms shown in FIGS. 5A to 5F, the shape of the terminal electrodes 42 is not limited to rectangular or circular, but may be other geometric shapes (eg, square or elliptical). Similarly, in the forms shown in FIGS. 5A to 5F, the outer contour of the exterior body when viewed from above is not limited to a circle, and may be an ellipse, for example. In addition, there are no particular restrictions on the position and/or layout of the terminal electrodes 42 in the second sealing portion 41, and they may be arranged in a desired position or in a desired layout according to product specifications. In other words, the terminal portion according to the present disclosure can have a high degree of freedom in designing the arrangement of the terminal electrodes.

FIG. 6 shows another variation of the arrangement of terminal electrodes 42 .
FIGS. 6A to 6F show, for example, a prismatic secondary battery having an exterior body 20 which is rectangular in plan view. That is, in FIGS. 6A to 6F, the outer contour of the exterior body 20 is rectangular when viewed from above.
6A to 6F, the second sealing portion 41 has a rectangular shape in plan view (that is, a rectangular outline outside plan view). However, the second sealing portion 41 is not limited to this, and may have another shape such as a square or a circle in a plan view (that is, a square or a circle outline outside the plan view).
In FIGS. 6A to 6C, the terminal electrode 42 has a rectangular shape in plan view (that is, a rectangular outline outside plan view).
In FIG. 6A, the terminal electrode 42 is arranged at the geometric center of the second sealing portion 41 . The terminal electrode may be arranged offset from the geometric center of the second encapsulant (ie, arranged off-center). In FIG. 6B, the terminal electrode 42 is offset leftward from the geometric center of the second sealing portion 41 . In FIG. 6C, the terminal electrode 42 is offset rightward from the geometric center of the second sealing portion 41 .
6D to 6F, the terminal electrode 42 has a circular shape in plan view.
In FIG. 6D, the terminal electrode 42 is arranged at the geometric center of the second sealing portion 41 . Similarly, the terminal electrode may be offset from (ie, displaced from) the geometric center of the second encapsulant. In FIG. 6E, the terminal electrode 42 is offset leftward from the geometric center of the second sealing portion 41 . In FIG. 6F, the terminal electrode 42 is offset rightward from the geometric center of the second sealing portion 41 .
In the forms shown in FIGS. 6A to 6F, the shape of the terminal electrodes 42 is not limited to rectangular or circular, but may be other geometric shapes (eg, square or elliptical). Similarly, in the forms shown in FIGS. 6A to 6F, the outer contour of the exterior body when viewed from above is not limited to a rectangle, and may be, for example, a square. Moreover, there is no particular limitation on the position where the terminal electrode 42 is arranged in the second sealing portion 41, and it may be arranged at a desired position according to the specifications of the product.

Thus, in the secondary battery of the present disclosure, the position of the terminal electrode can be freely designed according to the desired application. In other words, the secondary battery according to the present disclosure has a high degree of freedom in designing the terminal electrodes.

In the secondary battery of the first embodiment of the present disclosure, each member may be used in any combination as needed.

(Second embodiment)
A secondary battery according to the second embodiment of the present disclosure is illustrated in FIG. The secondary battery according to the second embodiment is provided with a further sealing structure (hereinafter also referred to as “second sealing structure” or “internal sealing structure”) inside the outer package. The secondary battery according to the second embodiment has a "double sealing structure" by having the second sealing structure together with the first sealing structure.

In the present disclosure, "additional sealing structure" mainly means a sealing structure that can be arranged inside the exterior body. Such a further encapsulation structure can form a "double encapsulation structure" in the secondary battery together with the first encapsulation structure described above.

By providing a further sealing structure (second sealing structure or internal sealing structure) inside the exterior body, the opening 21 can be closed from the inside of the exterior body, and the first sealing structure and the A "double encapsulation structure" can be formed. In such a double sealing structure, the sealing structures positioned on the outer side and the inner side of the outer package face each other with the opening of the outer package interposed therebetween. Such a double sealing structure makes it easier to suppress permeation of moisture such as water vapor and/or volatilized electrolytic solution from the outside, for example. In particular, it becomes easier to suppress the permeation of the volatilized electrolytic solution more remarkably.

In such a second embodiment, the second sealing structure has a "metal part" and a "joint part", and the joint part can be joined to the inner surface of the exterior body. That is, the second sealing structure can be bonded to the surface of the exterior body on the inner side corresponding to the area around the opening of the exterior body (on the inner surface of the exterior body). A structure having such a “metal portion” and a “bonding portion” and provided inside the exterior body can be referred to as a second sealing structure.

For example, as shown in FIG. 7, in the second embodiment, in addition to the sealing structure 30′ provided on the outer side of the exterior body (for example, the lid-like member 20a), a sealing structure as a further sealing structure 60 is provided inside the exterior body 20 (for example, the lid-like member 20a).

The second sealing structure 60 has a metal part 61 and a connecting part 62 for connecting the metal part 61 and the exterior body 20 (preferably the lid member 20a). The connecting portion 62 may be connected to the inner surface of the exterior body 20 (preferably the lid-like member 20a). In other words, the connecting portion 62 may be interposed between the metal portion 61 and the exterior body 20 (preferably the lid-like member 20a) even though it is provided inside the exterior body.

In the second sealing structure 60, mainly the metal portion 61 and the joint portion 62 facilitate, for example, remarkably suppressing the permeation of volatilized electrolytic solution and/or the permeation of moisture such as water vapor from the outside. In particular, permeation of volatilized electrolytic solution is likely to be suppressed more remarkably.

The metal part 61 can be physically and/or electrically connected to the first tab 11 that can extend from the electrode assembly 10 (see FIG. 7). As illustrated, the metal portion 61 may have a plate shape as a whole. The metal part 61 can have a planar view size equal to or larger than the opening size of the opening 21, for example. For example, the metal part 61 may have a planar view size equal to or larger than the planar view size of the terminal part 40 ′ provided on the outside of the exterior body.

The connecting portion 62 may have insulating properties, and has electrical insulating properties with respect to the exterior body 20 (for example, the lid-shaped member 20 a ) and the metal portion 61 . In such a case, the metal part 61 can be physically connected to the exterior body 20 (for example, the lid-like member 20a) through the connecting part 62, but can form a state in which it is not electrically connected. .

Although it is only an example, the term “insulation” (for example, insulation not only in the joint 62 but also in the second sealing portion 41) in this specification means the insulation that a general insulator has. It may have an electrical resistivity that a general insulator has, which is merely an example, but is at least 1.0×10 ⁵ Ω·m or more, preferably 1.0×10 ⁶ Ω·m or more, or more. It may preferably have a resistivity of 1.0×10 ⁷ Ω·m or more (at room temperature of 20° C.).

In the double sealing structure, for example, the metal part 61 (that is, the metal part of the internal sealing structure) and the terminal electrode 42' (that is, A conductive portion 80 may be provided for electrically connecting the terminal electrodes of the external sealing structure to each other.

The conductive portion 80 shown in FIG. 7 has one end surface directly connected to the second sealing portion 41′ and the terminal electrode 42′ of the terminal portion 40′ (see FIG. 7), and the other The end face is directly connected to the metal portion 61 (see FIG. 7).

In the secondary battery 103 according to the second embodiment shown in FIG. 7, for example, the terminal electrode 42', the conductive portion 80, the metal portion 61 and the first tab 11 are electrically connected to the positive electrode of the electrode assembly 10. you can In this case, the terminal electrode 42' can function as a positive terminal. On the other hand, the outer body 20 , eg, the cup-shaped member 20 b and the second tab 12 may be electrically connected to the negative electrode of the electrode assembly 10 . In this case, the exterior body 20 can function as a negative terminal.

The secondary battery 103 according to the second embodiment shown in FIG. 7 has a “double sealing structure” composed of a first sealing structure and a second sealing structure. Due to the first sealing portion 50, the second sealing portion 41', the joint portion 62, the metal portion 61, and the like, for example, the permeation of moisture such as water vapor from the outside and/or the volatilized electrolytic solution is increased. Remarkably easy to suppress.

The "metal portion", "bonding portion" and "conductive portion" relating to the second sealing structure will be described in detail below.

(metal part)
In the present disclosure, the “metal part” means a member having conductivity and containing at least one metal element. The metal part is indicated by reference numeral "61", for example as shown in FIG.

The metal part 61 contains, for example, at least one metal element selected from the group consisting of aluminum (Al), iron (Fe), chromium (Cr) and nickel (Ni).

The shape and dimensions of the metal part 61 are not particularly limited. For example, the metal part 61 preferably has a plate-like shape because it closes the opening of the exterior body. The thickness of the metal portion 61 is, for example, 0.1 mm or more and 1.0 mm or less.

Since the metal part 61 can be arranged inside the exterior body, it is preferable that the metal part 61 has corrosion resistance against, for example, an electrolytic solution. For example, the metal portion 61 may be made of an aluminum plate, a stainless steel plate and/or a nickel plate.

The metal part may be multi-layered. There is no particular limit to the number of layers that can be included in the metal part.

Metal portion 61 may comprise a clad material.
In the present disclosure, the “cladding material” means a member formed by simultaneously rolling and joining a plurality of metal materials. The metal part 61 may be, for example, a three-layer clad material 90 as shown in FIG. The clad material 90 used as the metal portion 61 may specifically include a first layer 91 , a second layer 92 and a third layer 93 .

The overall thickness of the clad material 90 is, for example, 0.1 mm or more and 1.0 mm or less.

The first layer 91 that can be included in the clad material 90 corresponds to the bottom layer, and since it may come into contact with, for example, an electrolytic solution, it preferably has corrosion resistance. The first layer 91 preferably contains, for example, aluminum, and is more preferably an aluminum plate. Alternatively, it may be made of the same material as the first tab 11 . The thickness of the first layer 91 is, for example, 0.1 mm or more and 1.0 mm or less.

The second layer 92 that can be included in the clad material 90 corresponds to the intermediate layer and preferably has physical strength and/or corrosion resistance. The second layer 92 preferably comprises, for example, stainless steel, more preferably a stainless steel plate. The thickness of the second layer 92 is, for example, 0.1 mm or more and 1.0 mm or less.

The third layer 93 that can be included in the cladding material 90 corresponds to the uppermost layer, and preferably has bonding properties with the connecting portion and the conductive portion. The third layer 93 preferably contains, for example, nickel, more preferably a nickel plate. The thickness of the third layer 93 is, for example, 0.1 mm or more and 1.0 mm or less.

(Coupling part)
In the present disclosure, the “joint portion” means a member that joins the metal portion and the inner surface of the exterior body, particularly the metal portion 61 and the inner surface of the lid-shaped member 20a. Preferably, the coupling portion is positioned around opening 21 . The joint is indicated by reference numeral "62", for example as shown in FIG.

The shape of the connecting portion 62 is not particularly limited. For example, the coupling portion 62 may have a plate-like shape. The thickness of the coupling portion 62 is, for example, 0.03 mm or more and 0.3 mm or less.

The connecting part 62 may have an opening similar to the opening of the exterior body. The connecting portion 62 is preferably arranged around the opening of the exterior body.

The coupling portion 62 has insulation against the metal portion and the exterior body. In other words, the connecting portion can inhibit electrical connection between the metal portion and the exterior body (preferably the lid-like member).

The connecting part 62 preferably has not only "insulating properties" but also "fusion properties" (or thermal adhesion properties).

As the coupling portion 62, for example, one containing a resin material or an elastomer material can be used. A thermoplastic resin, preferably a heat-sealable resin, can be used as the resin material. Examples of thermoplastic resins include polyolefin resins such as polyethylene and/or polypropylene, preferably polypropylene and copolymers thereof. As the connecting part 62, a single layer film of thermoplastic resin or a multilayer film containing thermoplastic resin can be used. An example of a multilayer film is a multilayer heat-fusible film in which a high-melting-point resin layer as an intermediate layer is sandwiched between low-melting-point resin layers (thermoplastic resin layers). Moreover, as an elastomer material, a polyester-based thermoplastic elastomer and the like can be mentioned.

The coupling portion 62 may have a film form. That is, the joint may have a membrane form, ie a thin form. For example, the joints may be provided using a film precursor having a morphology close to the final shape.

From another point of view, the joint 62 may contain an adhesive component that exhibits insulation. Examples of such adhesives include acrylic adhesives such as acrylic acid ester copolymers, rubber adhesives such as natural rubber, silicone adhesives such as silicone rubber, urethane adhesives such as urethane resin, α-olefin adhesives, ether adhesives, ethylene-vinyl acetate resin adhesives, epoxy resin adhesives, vinyl chloride resin adhesives, chloroprene rubber adhesives, cyanoacrylate adhesives, water-based polymers Isocyanate adhesives, styrene-butadiene rubber adhesives, nitrile rubber adhesives, nitrocellulose adhesives, reactive hot melt adhesives, phenol resin adhesives, modified silicone adhesives, polyamide resin adhesives , polyimide adhesive, polyurethane resin adhesive, polyolefin resin adhesive, polyvinyl acetate resin adhesive, polystyrene resin solvent adhesive, polyvinyl alcohol adhesive, polyvinylpyrrolidone resin adhesive, polyvinyl butyral resin adhesive Examples include adhesives, polybenzimidazole-based adhesives, polymethacrylate resin-based adhesives, melamine resin-based adhesives, urea resin-based adhesives, and/or resorcinol-based adhesives.

The connecting portion 62 provides insulation between the metal portion 61 and the inner surface of the exterior body 20, particularly between the metal portion 61 and the inner surface of the lid-like member 20a, and also prevents moisture such as water vapor and/or Permeation of the volatilized electrolytic solution or the like can be more significantly suppressed.

(Conductive part)
In the present disclosure, "conductive portion" means a conductive portion or member that can be provided or positioned between a metal portion and a terminal electrode. The conductive portion is indicated by reference numeral "80", for example as shown in FIG. The conductive part 80 electrically connects the sealing structure (first sealing structure) and the further sealing structure (second sealing structure) to each other. More specifically, the conductive portion serves for electrical connection between the metal portion and the terminal electrode. The conductive portion may be physically coupled to only the terminal electrode, only the second encapsulation, or both the terminal electrode and the second encapsulation, as long as it can make electrical contact with the terminal electrode. .

The thickness (or vertical length) of the conductive portion 80 is not particularly limited, and is, for example, 0.05 mm or more and 2.0 mm or less.

The conductive portion 80 is made of, for example, tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), cadmium (Cd), copper (Cu), gold (Au), indium (In), silver (Ag ), aluminum (Al), arsenic (As), iron (Fe), chromium (Cr), nickel (Ni), cobalt (Co), zinc (Zn), germanium (Ge), phosphorus (P), gallium (Ga ), silicon (Si) and manganese (Mn). By including the metal element in the conductive portion 80, the conductivity can be further enhanced. Silver paste, solder, or the like may be used as the conductive portion 80 . Alternatively, an elastic body such as a spring containing the metal element may be used as the conductive portion 80 . That is, a conductive portion that electrically connects the sealing structures may be provided as a spring member. In such a case, a secondary battery that is stronger against external impact can be provided.

In the secondary battery 103 according to the second embodiment shown in FIG. 7, the structure 30' is mentioned as a preferred aspect as the first sealing structure. The structure 30 ′ is composed of a terminal portion 40 ′ and a first sealing portion 50 . The terminal portion 40' has a second sealing portion 41' and a terminal electrode 42' provided on the second sealing portion 41'. Here, the terminal portion 40' may correspond to the terminal portion 40b shown in FIG. 4(B). Since the area of the lower side of the terminal electrode 42' is smaller than the area of the upper side of the terminal portion 40', the area of the lower side of the second sealing portion 41' can be made relatively larger. It is possible, and is superior in airtightness.

In the secondary battery according to the second embodiment, for example, other terminal portions shown in FIG. 4 can be used as the first sealing structure without particular limitation.

Moreover, the first sealing portion 50 and the outer package 20 used in the secondary battery 103 according to the second embodiment shown in FIG. 7, and the electrode assembly 10, the first tab 11 and the second Members such as tab 12 correspond to the respective members shown in FIG.

In the secondary battery 103 according to the second embodiment shown in FIG. 7, the first sealing portion 50 is interposed between the second sealing portion 41' and the exterior body 20 (preferably the lid-shaped member 20a). Then, the second sealing portion 41' and the exterior body 20 (preferably the lid member 20a) can be joined together. The first sealing portion 50 preferably comprises an inorganic sealing material, and may comprise at least one selected from the group consisting of metals, alloys and glass. Therefore, it is particularly excellent in bonding with the second sealing portion 41', which is also preferably made of inorganic ceramics. An alloy such as Kovar may be used as the first seal 50 .
(Modification of Second Embodiment)
As a modified example of the secondary battery 103 (FIG. 7) according to the second embodiment, another secondary battery 104 having a double sealing structure is shown in FIG.
The configuration of the secondary battery 104 is the same as that of the secondary battery according to the second embodiment shown in FIG. The configuration is the same as that included in the secondary battery 103 .

The protective layer 70 covers and protects at least a portion of the exterior body 20, and can further improve the bondability with the first sealing portion 50.

When the outer body 20 is a metal outer body, the protective layer 70 may be a plated layer. can be effective from a sexual point of view.

The protective layer 70 is made of, for example, gold (Au), silver (Ag), tin (Sn), copper (Cu), nickel (Ni), chromium (Cr), zinc (Zn), cobalt (Co), platinum (Pt ), rhodium (Rh), palladium (Pa), iridium (Ir) and ruthenium (Ru). When the protective layer 70 contains the metal element described above, the protection of the metal surface of the exterior body 20 and the bondability with the first sealing portion 50 are more likely to be improved.

The thickness of the protective layer is, for example, 0.3 μm or more and 20.0 μm or less. When the outer casing 20 is made of metal such as stainless steel and/or when the first sealing portion 50 is made of metal or an alloy such as Kovar, a nickel (Ni) plated layer is used as the protective layer 70 . you can This is because the protection of the surface of the exterior body 20 and/or the bondability with the first sealing portion 50 can be further improved. The protective layer 70 may be provided not only on the surface of the exterior body but also on the inner surface.

(Production method)
A secondary battery of the present disclosure will be described. A method for manufacturing a secondary battery having a double-sealed structure (see FIGS. 7 and 8) will be briefly described below as an example.

FIG. 10 illustrates a method of manufacturing a secondary battery (see FIGS. 7 and 8) having a double-sealed structure according to the second embodiment of the present disclosure.

Step (A): Step of Positioning the Exterior Body The exterior body 20 is positioned and arranged. The exterior body 20, particularly the lid-shaped member, can be formed by press working or the like. The step S is arbitrary. That is, the surface of the exterior body 20 may be flat (see FIG. 3). If necessary, at least part of the exterior body 20 may be covered with a protective layer 70 (see FIG. 8).

Step (B): Positioning Step of External Sealing Structure Preferably, the sealing structure 30 ′ prepared in advance is positioned on the upper side of the exterior body 20 so as to close the opening 21 . For example, a previously prepared sealing structure 30' is positioned and arranged so as to block the opening 21 on the upper side of the lid-like member. When the step S is provided, the sealing structure 30' prepared in advance is arranged in a region inside the step.
The sealing structure 30' is composed of a terminal portion 40' and a first sealing portion 50. The first sealing portion 50 is connected to the second sealing portion 41' of the terminal portion 40'. It may be pre-bonded, such as by welding, soldering and/or heating. The terminal portion 40' itself can be prepared by, for example, a sintering method (although this is merely an example, a method of laminating or printing and sintering a plurality of green sheets).

Step (C): Sealing and Joining Step The first sealing portion 50 is joined to the exterior body 20 from the inside (lower side) of the exterior body 20 by, for example, resistance welding, soldering, and/or heating along the direction of the arrow. .

By using the above steps (A) to (C), the external sealing structure (see FIGS. 2 and 3) of the secondary battery according to the first embodiment of the present disclosure can be similarly formed.

Step (D): Conductive Portion Joining Step While the conductive portion 80 is in electrical contact with the terminal electrode 42', the second sealing portion 41' and/or the terminal are bonded by, for example, welding, soldering and/or heating. It is coupled to electrode 42'.

Step (E): Bonding Step of Second Sealing Structure The second sealing structure 60 is bonded to the inner surface of the exterior body 20 by pressing and/or heating via the insulating bonding portion 62 . Whereas the insulating coupling portion 62 is pre-bonded to the second sealing structure 60 , the conductive portion 80 and/or the tab 11 (first tab) may also be pre-bonded to the metal portion 61 .

A secondary battery with a double-sealed structure can be finally obtained through the above processes. The above description is merely an example, and the manufacturing method of the secondary battery of the present disclosure is not limited to the above method.

Although the embodiments of the present invention have been described above, they are merely examples of typical examples. Therefore, those skilled in the art will easily understand that the present invention is not limited to this, and that various aspects are conceivable.

For example, although round (button-shaped or coin-shaped) and rectangular secondary batteries were mainly mentioned above (FIGS. 5 and 6), the present invention is not necessarily limited to these. In other words, the secondary battery of the present disclosure is not limited to having a circular or rectangular planar shape, and may have any other geometric shape. Similarly, the shape of the terminal electrode (particularly, the shape in plan view) is not necessarily limited to a rectangular shape or a circular shape, and may have other geometric shapes.

By the way, the term "rectangle" as used in this specification is not limited to being a perfect square, but also includes shapes that may be normally included in the "square shape" as recognized by those skilled in the art, even though they are modified from it. In addition, "circular" is not limited to a perfect circle (i.e., simply "circle" or "perfect circle"), but may be modified from a shape that can be normally included in "round" as recognized by those skilled in the art. also includes For example, not only circles and perfect circles, but also arcs with locally different curvatures, and shapes derived from circles and perfect circles, such as ellipses, may be used. In a typical example, such a battery having a circular shape in plan view corresponds to a so-called button-shaped or coin-shaped battery.

In addition, although the above description refers to the drawings assuming that the electrode assembly has a planar laminated structure or a wound laminated structure in particular, the present invention does not necessarily include an electrode assembly having a planar laminated structure or a wound laminated structure. It is not limited to secondary batteries comprising solids. In other words, the electrode assembly may be based on, for example, a stack-and-folding type structure, unless it is a feature specific to a planar lamination type structure or a wound lamination type structure.

The secondary battery of the present disclosure can be used in various fields where battery use or power storage can be assumed. Although it is only an example, the secondary battery of the present disclosure can be used in the electric / information / communication field where electric / electronic equipment etc. can be used (for example, mobile phones, smartphones, laptops and digital cameras, activity meters, arm computers , electronic paper, wearable devices, RFID tags, card-type electronic money, electric and electronic equipment fields including small electronic devices such as smart watches, and mobile equipment fields), household and small industrial applications (e.g., power tools, golf Carts, household/nursing/industrial robots), large industrial applications (e.g. forklifts, elevators, harbor cranes), transportation systems (e.g. hybrid vehicles, electric vehicles, buses, trains, electric assist bicycles, electric motorcycles, etc.), power system applications (for example, various power generation, road conditioners, smart grids, general household electrical storage systems, etc.), medical applications (medical equipment such as earphone hearing aids), medical applications (fields such as medication management systems), as well as IoT fields, space/deep-sea applications (for example, fields such as space probes and submersible research vessels).

Reference Signs List 1 positive electrode 2 negative electrode 3 separator 5

electrode configuration layer

10, 110 electrode assembly 11 first tab 12

second tab

20, 120 exterior body 20a lid-shaped member 20b cup-shaped

member

21, 121 opening 30 sealing structure/first Sealing structure 40 Terminal part 41 Further sealing part/Second sealing part 42 Terminal electrode 43, 44, 45, 46 Layered member 50 Sealing part/First sealing part 60 Further sealing structure/ Second sealing structure 61 metal part 62 joint part 70 protective layer 80 conductive part 90 clad material 91 first layer 92 second layer 93

third layer

100, 101, 102, 103, 104 secondary battery 111 tab 130 metal plate 140 sealing member S step

Claims

an exterior body;
and an electrode assembly housed inside the exterior body,
The exterior body has an opening, and a sealing structure is provided so as to close the opening,
The sealing structure is composed of a terminal portion and a sealing portion,
The terminal portion has a second sealing portion and a terminal electrode provided on the second sealing portion,
The secondary battery, wherein the sealing portion is interposed between the second sealing portion and the exterior body.
2. The two according to claim 1, wherein both the sealing portion of the sealing structure and the second sealing portion of the terminal portion are non-resin sealing portions made of a non-resin material. next battery.
3. The secondary battery according to claim 1, wherein said second sealing portion has insulating properties.
The secondary battery according to any one of claims 1 to 3, wherein the second sealing portion contains ceramics.
The secondary battery according to any one of claims 1 to 4, wherein said terminal portion has a multilayer structure.
The secondary battery according to any one of claims 1 to 5, wherein said sealing portion of said sealing structure contains at least one selected from the group consisting of metal, alloy and glass.
7. The secondary battery according to claim 1, wherein said terminal electrode extends between both main surfaces of said terminal portion.
The secondary battery according to any one of claims 1 to 6, wherein said terminal portion further has a conductor, and said conductor is connected to said terminal electrode.
In the terminal portion, a metal layer provided inside the second sealing portion and not electrically connected to the terminal electrode extends in a direction perpendicular to the thickness direction of the terminal portion. The secondary battery according to any one of claims 1 to 8.
10. The secondary battery according to any one of claims 1 to 9, wherein a further sealing structure is provided inside said exterior body to have a double sealing structure.
11. The double sealing structure according to claim 10, wherein the sealing structures located on the exterior side and the interior side of the exterior body face each other across the opening of the exterior body. secondary battery.
The further sealing structure has a metal part and a connecting part for connecting the metal part and the outer body, and the connecting part is connected to the inner surface of the outer body. 12. The secondary battery according to claim 10 or 11.
13. The secondary battery according to claim 12, wherein said joint has insulating properties.
14. The secondary battery according to claim 12, wherein said metal portion comprises a clad material.
15. The method according to any one of claims 10 to 14, further comprising a conductive portion for electrically connecting said metal portion of said further sealing structure and said terminal electrode of said sealing structure to each other. A secondary battery as described.