WO2021140838A1

WO2021140838A1 - Secondary battery

Info

Publication number: WO2021140838A1
Application number: PCT/JP2020/046570
Authority: WO
Inventors: 健太江口
Original assignee: 株式会社村田製作所
Priority date: 2020-01-10
Filing date: 2020-12-14
Publication date: 2021-07-15

Abstract

Provided is a secondary battery that includes: an electrode assembly; an exterior body for housing said electrode assembly; and an external output terminal for electrically connecting the electrode assembly to the outside. In said secondary battery, the electrode assembly is provided with a positive electrode and a negative electrode, the positive electrode is provided with an electrode current collecting tab, and the negative electrode is provided with a negative electrode current collecting tab. At least one of the positive electrode current collecting tab and the negative electrode current collecting tab is connected to the external output terminal. The external output terminal is disposed so as to be inclined with respect to at least one flat exterior main surface of the the exterior body.

Description

Secondary battery

The present invention relates to a secondary battery. In particular, the present invention relates to a secondary battery including an electrode assembly in which electrode constituent layers including a positive electrode, a negative electrode and a separator are laminated.

Since the secondary battery is a so-called storage battery, it can be repeatedly charged and discharged, and is used for various purposes. For example, secondary batteries are widely used as battery packs for mobile devices such as mobile phones, smartphones and notebook computers, and hybrid vehicles and electric vehicles.

Japanese Unexamined Patent Publication No. 2012-243405

The inventors of the present application realized that there was a problem to be overcome with the conventional secondary battery, and found that it was necessary to take measures for that purpose. Specifically, the inventors of the present application have found that there are the following problems.

A secondary battery usually consists of an electrode assembly (or an electrode group) formed by laminating an electrode constituent layer including a positive electrode, a negative electrode, and a separator between them, and an exterior body capable of accommodating or wrapping the electrode assembly. Consists of having and. The exterior body is provided with, for example, at least one output terminal used for connection with an external device or the like, that is, an "external output terminal" (more specifically, a positive electrode terminal, a negative electrode terminal, or both electrode terminals). (For example, Patent Document 1).

The external output terminal is usually provided so as to protrude from the exterior body. In order to connect to an external device, the dimensions including the external output terminal should be generally considered as the dimensions of the entire secondary battery. Therefore, it is necessary to reduce the overall size of the secondary battery by preventing the external output terminal from protruding from the exterior body as much as possible. In other words, there was a need for "miniaturization" of the entire secondary battery.

Further, for example, in the conventional button-shaped (or coin-shaped) secondary battery shown in FIG. 9, in order to secure a space for accommodating a current collecting tab that is electrically connected to an external output terminal, an electrode assembly ( Specifically, there was a situation that a part of the electrode) had to be cut. In such a case, there is a problem that the capacity of the battery is reduced by cutting the electrodes (see FIG. 9B). Note that FIG. 9A schematically shows a conventional button-shaped secondary battery, and FIG. 9B schematically shows a horizontal cross section of the conventional button-shaped secondary battery.
Further, as shown in the vertical cross-sectional view of FIG. 10, the space provided for accommodating the current collecting tab inside the exterior of the secondary battery _{includes a dead space (S 100} ), so that the internal space is effectively used. There was also the problem that it could not be used. It was also found that these problems also occur in a rectangular secondary battery (see FIG. 11). 11 (a) schematically shows a conventional square secondary battery, and FIG. 11 (b) schematically shows a horizontal cross section of the conventional square secondary battery. c) schematically shows the vertical cross section of the conventional square secondary battery.

The invention of the present application has been made in view of such a problem. That is, the main purpose is to make the secondary battery smaller by improving the arrangement of the external output terminals. It is also an object to increase the capacity of the battery and to make more effective use of the dead space inside the exterior.

As a result of diligent research, the inventors of the present application have referred to external output terminals (or simply referred to as "external terminals" or "terminals") such as positive electrode terminals or negative electrode terminals, for example, as shown in FIGS. By providing it "diagonally" with respect to at least one flat exterior main surface (for example, upper surface, lower surface) of the exterior body of the secondary battery, it is more specifically positioned at least a part of the "periphery" of the exterior body. It has been found that by providing the external output terminals (21, 31) on the "tilted surface" (22, 32), the size of the entire battery can be made relatively smaller than that of the conventional secondary battery. (For example, FIG. 5).
In addition, the "diagonal" arrangement of the external output terminals allows the current collecting tabs to be more compactly housed below the external output terminals (or below the inclined surface), which makes dead space inside the exterior more effective. It was also found to be available (eg Figure 6). As a result, it was also found that the capacity of the battery can be relatively increased (for example, FIG. 6). In this way, the inventors of the present application have completed the invention of the secondary battery in which the above-mentioned main object is achieved.

In the present invention, the electrode assembly, the exterior body accommodating the electrode assembly, and the outside for electrically connecting the electrode assembly and the outside (external to the secondary battery, specifically, an external device, etc.). A secondary battery including an output terminal, wherein the electrode assembly includes a positive electrode and a negative electrode, the positive electrode has a positive electrode current collecting tab, the negative electrode has a negative electrode current collecting tab, and the positive electrode current collecting tab. A secondary battery in which at least one of the negative electrode current collecting tabs is connected to the external output terminal, and the external output terminal is provided obliquely with respect to at least one flat exterior main surface of the exterior body. Provided. In the present disclosure, the above-mentioned secondary battery may be referred to as "the secondary battery of the present disclosure".

The secondary battery of the present disclosure is more preferably provided with an external output terminal arranged "diagonally", and the size of the entire secondary battery is reduced. In addition, the dead space inside the exterior can be used more effectively. Furthermore, the capacity of the secondary battery can be increased.

FIG. 1 is a cross-sectional view schematically showing the configuration of the electrode assembly (FIG. 1 (a): non-winding plane laminated type, FIG. 1 (b): wound type). FIG. 2 is a schematic perspective view showing a secondary battery according to an embodiment of the present invention. FIG. 3 is a schematic plan view showing a secondary battery according to an embodiment of the present invention. FIG. 4 is a schematic side view showing a secondary battery according to an embodiment of the present invention. FIG. 5 compares the dimensions of the secondary battery according to the embodiment of the present invention as seen from the lateral direction (or horizontal direction) with the dimensions of the conventional secondary battery as viewed from the lateral direction (or horizontal direction). It is a schematic side view. FIG. 6 is a schematic cross-sectional view comparing the internal configuration of the secondary battery according to the embodiment of the present invention with the internal configuration of the conventional secondary battery. FIG. 7 is a schematic schematic cross-sectional view showing a secondary battery according to an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing a secondary battery according to an embodiment of the present invention. FIG. 9 is a schematic view showing a conventional button-shaped (or coin-shaped) secondary battery having an external output terminal. FIG. 10 is a schematic view showing a schematic vertical cross section of a conventional button-shaped (or coin-shaped) secondary battery having an external output terminal. FIG. 11 is a schematic view showing a conventional rectangular secondary battery having an external output terminal.

Hereinafter, the present invention will be described in more detail with reference to the secondary battery according to the embodiment of the present invention. Although explanations will be given with reference to the drawings as necessary, the various elements in the drawings are merely schematically and exemplified for the understanding of the present invention, and the appearance, dimensional ratio, etc. may differ from the actual ones. ..

The "cross-sectional view" described directly or indirectly herein is a virtual cutout of a secondary battery along the stacking or stacking direction of the electrode assembly or electrode constituent layers that make up the secondary battery. Based on cross section (see Figure 1). Similarly, the direction of "thickness" as described directly or indirectly herein is based on the stacking direction of the electrode materials that make up the secondary battery. For example, in the case of a "plate-shaped thick secondary battery" such as a button type (or coin type), the direction of "thickness" corresponds to the plate thickness direction of such a secondary battery. As used herein, "planar view" is based on a sketch of an object viewed from above or below along the direction of such thickness.

Further, the "vertical direction" and the "horizontal direction" used directly or indirectly in the present specification correspond to the vertical direction and the horizontal direction in the figure, respectively. Unless otherwise specified, the same code or symbol shall indicate the same member or part or the same meaning. In one preferred embodiment, it can be considered that the vertical downward direction (that is, the direction in which gravity acts) corresponds to the "downward direction" and the opposite direction corresponds to the "upward direction".

[Basic configuration of secondary battery]
The term "secondary battery" as used herein refers to a battery that can be repeatedly charged and discharged. Therefore, the secondary battery according to the embodiment of the present invention is not excessively bound by its name, and may include, for example, a power storage device.

The secondary battery according to the embodiment of the present invention includes, for example, an electrode assembly in which electrode constituent layers including a positive electrode, a negative electrode, and a separator are laminated. For example, FIGS. 1 (a) and 1 (b) illustrate the electrode assembly 10. As shown, the positive electrode 1 and the negative electrode 2 may be stacked with each other via the separator 3 to form an electrode constituent layer 5. At least one or more of these electrode constituent layers 5 may be laminated to form the electrode assembly 10. In a secondary battery, such an electrode assembly may be enclosed in an exterior body together with an electrolyte (for example, a non-aqueous electrolyte). The structure of the electrode assembly is not necessarily limited to the planar laminated structure (see FIG. 1A), and for example, the electrode unit (or electrode) including the positive electrode, the negative electrode, and the separator arranged between the positive electrode and the negative electrode. It may have a winding type structure (see FIG. 1B) (for example, a jelly roll structure) in which the constituent layer) is wound in a roll shape. That is, as shown in FIG. 1A, for example, the electrode assembly 10 may have a flat laminated structure in which the electrode constituent layers 5 are laminated so as to be stacked on each other. Alternatively, the electrode assembly 10 may have a winding structure in which the electrode constituent layer 5 extending in a strip shape for a relatively long time is wound in a roll shape, for example, as shown in FIG. 1 (b). ..
Note that FIG. 1B merely illustrates a wound structure of the electrode assembly, and the electrode assembly is placed inside the exterior with the cross section shown in FIG. 1B set to "upward" or "downward". It may be placed in.
Further, the electrode assembly may have, for example, a so-called stack-and-folding structure in which a positive electrode, a separator and a negative electrode are laminated on a long film and then folded.

The positive electrode is composed of at least a positive electrode material layer and, if necessary, a positive electrode current collector. The positive electrode material layer contains a positive electrode active material as an electrode active material. The positive electrode current collector may or may not be present in the positive electrode. When a positive electrode current collector is present on the positive electrode, a positive electrode material layer may be provided on at least one surface of the positive electrode current collector on the positive electrode. For example, each of the plurality of positive electrodes in the electrode assembly may have positive electrode material layers provided on both sides of the positive electrode current collector, or positive electrode material layers may be provided on only one side of the positive electrode current collector. It may be the one that exists. For example, the positive electrode current collector may have a foil form. That is, the positive electrode current collector may be composed of the metal foil.

The negative electrode is composed of at least a negative electrode material layer and, if necessary, a negative electrode current collector. The negative electrode material layer contains a negative electrode active material as an electrode active material. The negative electrode current collector may or may not be present in the negative electrode. When the negative electrode current collector is present in the negative electrode, the negative electrode material layer may be provided on at least one surface of the negative electrode current collector in the negative electrode. For example, each of the plurality of negative electrodes in the electrode assembly may have negative electrode material layers provided on both sides of the negative electrode current collector, or negative electrode material layers may be provided on only one side of the negative electrode current collector. It may be the one that exists. For example, the negative electrode current collector may have a foil form. That is, the negative electrode current collector may be composed of the metal foil.

The electrode active material, that is, the positive electrode active material and the negative electrode active material, which can be contained in the positive electrode material layer and the negative electrode material layer, are substances that can be directly involved in the transfer of electrons in the secondary battery, respectively, and are charged and discharged, that is, the battery reaction. It is the main material of the positive electrode and the negative electrode.

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

The positive electrode material layer and the negative electrode material layer may be particularly layers capable of occluding and releasing lithium ions. That is, the secondary battery according to the embodiment of the present invention is a non-aqueous electrolyte secondary battery in which lithium ions can move between the positive electrode and the negative electrode via the non-aqueous electrolyte to charge and discharge the battery. You may be.

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

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

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

As described above, the positive electrode material layer and the negative electrode material layer can also be referred to as a "positive electrode mixture layer" and a "negative electrode mixture layer", respectively, because of the form in which a plurality of components are contained.

The positive electrode active material may be, for example, a substance that contributes to the occlusion and release 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, such a lithium transition metal composite oxide may be contained as a positive electrode active material in the positive electrode material layer of the secondary battery according to the embodiment of the present invention. For example, the positive electrode active material may be lithium cobalt oxide, lithium nickel oxide, lithium manganate, lithium iron phosphate, or a part of the transition metal thereof replaced with another metal.

Although such a positive electrode active material may be contained as a single species, it may 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, but is limited to polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, and polytetrafluoroethylene. At least one species selected from the group consisting of the above can be mentioned.

The conductive auxiliary agent that can be contained in the positive electrode material layer is not particularly limited, but is limited to carbon black such as thermal black, furnace black, channel black, ketjen black and acetylene black, graphite, carbon nanotubes, and vapor phase growth. At least one selected from carbon fibers such as carbon fibers, metal powders such as copper, nickel, aluminum and silver, and polyphenylene derivatives can be mentioned.

The thickness dimension of the positive electrode material layer is not particularly limited, but 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 any 10 points may be adopted.

The negative electrode active material may be a substance that contributes to the occlusion and release 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 (specifically, natural graphite and / or artificial graphite, etc.), hard carbon, soft carbon, diamond-like carbon, and the like. In particular, graphite has high electron conductivity and 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, lithium oxide and the like 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 an alloy of a metal that can be alloyed with lithium, for example, Al, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, It may be a binary, ternary or higher alloy of a metal such as Zn or La and lithium.

Such an alloy 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 binder that can be contained in the negative electrode material layer is not particularly limited, but is at least one selected from the group consisting of styrene-butadiene rubber, polyacrylic acid, polyvinylidene fluoride, polyimide-based resin, and polyamide-imide-based resin. Can be mentioned.

The conductive auxiliary agent that can be contained in the negative electrode material layer is not particularly limited, but is limited to carbon black such as thermal black, furnace black, channel black, ketjen black and acetylene black, graphite, carbon nanotubes, and vapor phase growth. At least one selected from carbon fibers such as carbon fibers, metal powders such as copper, nickel, aluminum and silver, and polyphenylene derivatives can be mentioned.

The thickness dimension of the negative electrode material layer is not particularly limited, but 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 negative electrode material layer is the thickness inside the secondary battery, and the average value of the measured values at any 10 points may be adopted.

The positive electrode current collector and the negative electrode current collector that can be used for the positive electrode and the negative electrode are members capable of collecting and supplying electrons generated by the electrode active material due to the battery reaction. Such an electrode current collector may be a sheet-shaped metal member. Further, such an electrode current collector may have a perforated or perforated form. For example, the current collector may be a metal leaf, a punching metal, a net or an expanded metal, a plate, or the like.

The positive electrode current collector that can be used for the positive electrode may be made 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, an aluminum foil.

The negative electrode current collector that can be used for the negative electrode may be made 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, a copper foil.

In the present disclosure, "stainless steel" (SUS) refers to, for example, stainless steel defined in "JIS G0203 steel terminology", and is an alloy steel containing chromium or chromium and nickel. It's okay.

The thickness dimensions of the positive electrode current collector and the negative electrode current collector are not particularly limited, but 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 the average value of the measured values at any 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 a short circuit due to contact between the positive electrode and the negative electrode and retaining the electrolyte. In other words, it can be said that the separator is a member capable of passing ions 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 film morphology due to its small thickness. Although only an example, a microporous polyolefin membrane may be used as the separator.

The microporous membrane that can be used as a separator may contain, for example, only polyethylene (PE) or polypropylene (PP) as the polyolefin. Furthermore, the separator may be a laminate that can be composed of a "microporous membrane made of PE" and a "microporous membrane made of PP". 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, but 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 any 10 points may be adopted.

In the present invention, the separator should not be particularly bound by its name, and may be a solid electrolyte, a gel-like electrolyte, and / or insulating inorganic particles having the same function.

In the secondary battery according to the embodiment of the present invention, for example, an electrode assembly including an electrode constituent 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 movement of metal ions released from the electrodes (positive electrode and / or negative electrode). The electrolyte may be an organic electrolyte and / or a "non-aqueous" electrolyte comprising organic solvents and the like, or it may be a "water-based" electrolyte containing water.

When the positive electrode and the negative electrode have a layer capable of occluding and releasing lithium ions, the electrolyte is an "non-aqueous" electrolyte (hereinafter referred to as "non-aqueous electrolyte") containing an organic electrolyte and / or an organic solvent and the like. Is preferable. That is, it is preferable that the electrolyte is a non-aqueous electrolyte. In the electrolyte, there will be metal ions released from the electrodes (positive electrode and / or negative electrode), and therefore the electrolyte can assist in the movement of the metal ions in the battery reaction.

The secondary battery according to the embodiment of the present invention is preferably a non-aqueous electrolyte secondary battery in which a "non-aqueous" electrolyte containing a "non-aqueous" solvent and a solute is used as the electrolyte. The electrolyte may have a form such as liquid or gel (note that the “liquid” non-aqueous electrolyte is also referred to as “non-aqueous electrolyte solution” in the present specification).

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

Although not particularly limited, the 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 the chain carbonates include at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl 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 chain carbonates may be used as the non-aqueous electrolyte, for example ethylene carbonate (EC) and diethyl carbonate ( A mixture with DEC), a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC), and the like may be used. As a specific non-aqueous electrolyte solute, for example, a Li salt such as _{LiPF 6} and / or LiBF _{4 may be used.}

The exterior body of the secondary battery is, for example, a member capable of accommodating or wrapping an electrode assembly formed by laminating electrode constituent layers including a positive electrode, a negative electrode, and a separator. As will be described later, in the present invention, the exterior body may be a metal exterior body having a non-laminated structure.

In the present invention, the above configuration may be appropriately changed or modified as necessary.

[Characteristics of the secondary battery of the present disclosure]
The secondary battery of the present disclosure includes an electrode assembly, an exterior body that houses the electrode assembly, and an electrical connection between the electrode assembly and the outside (or the outside of the secondary battery, specifically, an external device or the like). It has at least one external output terminal (more specifically, a positive electrode terminal, a negative electrode terminal, or both electrode terminals) for performing the above (hereinafter, “external terminal”, “output terminal”, “electrode”. Sometimes referred to as "terminal" or simply "terminal"). The secondary battery of the present disclosure is characterized by such an arrangement of external output terminals. That is, in the secondary battery, it is characterized in that the external output terminal used for connection with an external device or the like is arranged on the outer body.

In the secondary battery according to the embodiment of the present invention, the "external output terminal" described in detail below is provided "diagonally" with respect to the "at least one flat exterior main surface of the exterior body" of the secondary battery. It is characterized by being. In the present disclosure, "oblique" means that the "flat exterior main surface" described in detail below is angled at least greater than 0 °, for example, greater than 0 ° and greater than 90 °. It means that it is angled in a small range.

In the present disclosure, the "at least one flat exterior main surface of the exterior body" means any surface of the exterior body as long as it is the "flat main surface" of the exterior body. Here, the "flat main surface" of the exterior body means a main surface of the exterior body having at least a flat portion (or at least an intentionally provided non-concavo-convex portion).

In the invention of the present disclosure, the "flat exterior main surface" may be at least one of the "upper surface" and the "lower surface" facing each other in the thickness direction of the exterior body. Here, the thickness direction of the exterior body means, for example, the stacking direction when the electrode assembly has a laminated structure. Hereinafter, in the present disclosure, it is desirable that the description of "upper surface" and "lower surface" of the exterior body follows the above definition.

In the invention of the present disclosure, the "flat exterior main surface" is preferably a surface parallel to the main surface of the electrode assembly, more preferably the "upper surface" or "lower surface" of the exterior body parallel to the main surface of the electrode assembly. ".

In the invention of the present disclosure, the "main surface" of the electrode assembly or the exterior body may refer to one of the surfaces having the largest area regardless of the presence or absence of unevenness. For example, in the embodiments shown in FIGS. 2 to 4, the "main surface" of the exterior body may refer to the "lower surface" of the battery. Further, when the inclined surface is not considered, it may refer to the surface having the largest area. For example, in the embodiments shown in FIGS. 2 to 4, the "upper surface" of the exterior body may be referred to as the "main surface" (for example, FIG. 3).

For example, in the rectangular secondary battery 20 shown in FIG. 2A, the external output terminal 21 is provided "obliquely" with respect to the upper surface or the lower surface (particularly the upper surface) of the exterior body 23. Further, also in the button-shaped (or coin-shaped) secondary battery 30 shown in FIG. 2B, the external output terminal 31 is provided "obliquely" with respect to the upper surface or the lower surface (particularly the upper surface) of the exterior body 33. There is. Here, it should be noted that the shape of the secondary battery of the present disclosure is not limited to the square shape and the button shape (or coin shape).

As a specific means for providing the "external output terminal""diagonally" in the secondary battery of the present disclosure, for example, as shown in the schematic plan view of FIG. 3, the exterior body (23, 30) of the secondary battery (20, 30) is provided. 33) may be provided with "inclined surfaces" (22, 32). By providing such inclined surfaces (22, 32), the external output terminal (21) is provided with respect to the main surface (specifically, the upper surface or the lower surface, more specifically, the upper surface shown in the plan view of FIG. 3) of the exterior body. , 31) can be more easily provided "diagonally". In the invention of the present disclosure, such an inclined surface may be curved in a convex shape or may be recessed in a concave shape, for example.
FIG. 3A schematically shows a rectangular secondary battery 20 in a plan view, and FIG. 3B schematically shows a button-type secondary battery 30 in a plan view.

More specifically, as shown in the schematic plan view of FIG. 3, the inclined surface (22, 32) can be positioned on _{the “periphery” or edge (E a} , E _{b) of the exterior body (23, 33).} .. Here, the "periphery" of the exterior body generally means the entire peripheral edge (outer shape) of the outer body, and more specifically, the peripheral edge (outer shape) in the plan view of the outer body. By positioning the inclined surface on the peripheral edge of the exterior body, access to the external output terminal provided "diagonally" becomes easy.

The inclined surfaces (22, 32) are shown in a substantially rectangular shape or a substantially arc shape in the plan view of FIG. 3, for example, but in the present invention, the shape of the inclined surface is not particularly limited. Further, the size and area of the inclined surface are not particularly limited.

As shown in the schematic side view of FIG. 4A, in the secondary battery 40 according to another embodiment of the present invention, the inclined surface 42 has an angle θ ₁ with respect to the upper surface of the exterior body 43 of the secondary battery 40. It is provided. The angle θ ₁ is, for example, within the range of angles greater than 0 ° and less than 90 °. This angle θ ₁ is preferably in the range of 30 ° or more and 60 ° or less.
Further, the inclined surface 42 is provided at an _{angle θ 2} with respect to the lower surface of the exterior body 43 of the secondary battery 40. The angle θ ₂ is, for example, within the range of angles greater than 0 ° and less than 90 °. This angle θ ₂ is preferably in the range of 30 ° or more and 60 ° or less.
When the upper surface and the lower surface of the secondary battery 40 are parallel to each other, _{the value of the angle θ 1} is equal to the value of the angle θ ₂ .

Here, it should be noted that the shape of the secondary battery 40 shown in FIG. 4A is not limited to the square shape and the button shape (or coin shape). Further, in FIG. 4A, the external output terminal is omitted for convenience of explanation.

As shown in the schematic side view of FIG. 4B, the external output terminal 41 of the secondary battery 40 is provided on the inclined surface 42, but the position where the external output terminal 41 is arranged is not particularly limited.
The external output terminal 41 is preferably arranged in a _{space (or space) S 40} above (or above) the inclined surface 42. This is because the space S ₄₀ is a dead space in the conventional secondary battery (for example, the dead space S _{100 of the} _{conventional secondary battery 100 shown in FIG. 10 and the dead space S 200 of the} conventional secondary battery 200 shown in FIG. 11). ) Can correspond to the space that was thought to be. _{By arranging the external output terminal 41 in the space S 40} via the inclined surface 42 as shown in FIG. 4B, the dead space inside the exterior of the conventional secondary battery can be used more effectively.

Further, according to the invention of the present disclosure, for example, as shown in FIG. 5 (upper), the external output terminal 41 is arranged "obliquely" with respect to the upper surface (or lower surface) of the exterior body 43 of the secondary battery 40. More specifically, by providing the external output terminal 41 on the inclined surface 42, the size of the entire secondary battery can be made relatively smaller. In other words, the "miniaturization" of the entire secondary battery can be achieved.

For example, according to the schematic side view of FIG. 5 (bottom), in the conventional secondary battery 140, the external output terminal 141 projects outward from the exterior body 143, but the secondary battery 40 of the present disclosure (FIG. 5). In (above)), the external output terminal 41 is arranged “obliquely” in the _{space S 40, for example, via the inclined surface 42.} Therefore, in the secondary battery 40 of the present disclosure, in the side view from the side (horizontal direction), the external output terminal 141 of the conventional secondary battery 140 protrudes from the exterior body 143 (that is, FIG. 5 (bottom) of the example). The secondary battery can be miniaturized by the distance D _{1) shown in.}

In the secondary battery 40 of the present disclosure, for example, as shown in the schematic vertical cross-sectional view of FIG. 6 (top), a current collecting tab 44 extending from the electrode assembly 45 is connected to the external output terminal 41. There is. Here, the current collector tab 44 is attached to the electrode assembly 45 even if it is a positive electrode current collector tab 44a (not shown) that can extend from the positive electrode (or positive electrode current collector) that can be included in the electrode assembly 45. It may be a negative electrode current collector tab 44b (not shown) that can extend from a possible negative electrode (or negative electrode current collector). In other words, at least one of the positive electrode current collecting tab 44a and the negative electrode current collecting tab 44b that may extend from the electrode assembly 45, preferably one of them, more preferably the positive electrode current collecting tab 44a is connected to the external output terminal. .. Two or more external output terminals may be provided and the positive electrode current collecting tab 44a and the negative electrode current collecting tab 44b may be connected separately.

In the secondary battery 40, the external output terminal 41 may be one terminal of the positive electrode and the negative electrode, and the exterior body 43 may form the other terminal of the positive electrode and the negative electrode.

For example, when the external output terminal 41 is connected to the positive electrode current collecting tab 44a, the external output terminal 41 can function as a positive electrode terminal. At this time, when the exterior body is a metal exterior body, the other negative electrode current collecting tab 44b may be directly connected to the exterior body 43. At this time, the metal exterior body may serve as the negative electrode terminal. With such a configuration, the negative electrode area can be designed to be larger than that of the positive electrode.
Alternatively, when the external output terminal 41 is connected to the negative electrode current collecting tab 44b, the external output terminal 41 can function as a negative electrode terminal. At this time, when the exterior body is a metal exterior body, the other positive electrode current collecting tab 44a may be directly connected to the exterior body 43. At this time, the metal exterior body may serve as the positive electrode terminal.

Further, the current collecting tab having the opposite polarity to the current collecting tab that can be connected to the external output terminal 41 can be connected to an arbitrary place (for example, an inclined surface) of the exterior body via another output terminal like the external output terminal 41. May be indirectly and separately connected to. In the present disclosure, the term "indirectly" connecting the current collecting tab to the exterior body means that the current collecting tab is not directly electrically connected to the exterior body, but is another member (for example, an output terminal). It means that it is connected to the exterior body via such as. When the exterior body is a metal exterior body, it is preferable that the output terminal is attached to the metal exterior body via an insulating member such as an insulating member. Alternatively, the output terminal may be directly electrically connected to the exterior body without the intervention of an insulating member such as an insulating member.

Here, the configurations of the positive electrode current collecting tab 44a and the negative electrode current collecting tab 44b are not particularly limited as long as they can extend from the electrode assembly (specifically, the positive electrode and the negative electrode). For example, it may be composed of overlapping protruding portions of a plurality of current collectors (positive electrode current collector, negative electrode current collector) that can be provided on each of the positive electrode and the negative electrode.
For example, the positive electrode current collector tab 44a that can extend from the electrode assembly has a configuration in which the protruding portions of the positive electrode current collectors of the plurality of positive electrodes that can form the electrode assembly are integrated on the tip side. You can do it. Similarly, the negative electrode current collector tab 44b that can extend from the electrode assembly has a configuration in which the protruding portions of the negative electrode current collectors of the plurality of negative electrodes that can form the electrode assembly are integrated on the tip side. May have.
It is preferable that the positive electrode current collector tab 44a and the negative electrode current collector tab 44b can be integrally formed from the same material as the positive electrode current collector and the negative electrode current collector, respectively, and the shape and dimensions thereof are particularly limited. Absent.
It is preferable that the positive electrode current collecting tab 44a and the negative electrode current collecting tab 44b are arranged in a non-contact relationship with each other.

For example, as shown in FIG. 6 (bottom), the conventional secondary battery 140 has a problem that a _{dead space S 140 is generated when a space for accommodating the current collecting tab 144 is secured.} On the other hand, in the secondary battery 40 (FIG. 6 (top)) of the present disclosure, the external output terminal 41 can be arranged “diagonally” in the space (or space) S ₄₀ _{that can correspond to the conventional dead space S 140.} Therefore, the current collecting tab 44 (positive electrode current collecting tab 44a and / or negative electrode current collecting tab 44b) is successfully placed below (or below) the external output terminal 41 (or inclined surface 42) arranged "diagonally". Can be placed and accommodated.

As described above, the current collector tab 44 (positive electrode current collector tab 44a and / or negative electrode current collector tab 44b) is a collection of current collectors (positive electrode current collector and / or negative electrode current collector) that can extend from the electrode assembly. It may be in the state of being overlapped (or in the state of being overlapped or in the state of being joined). Therefore, in the invention of the present disclosure, such bulky aggregates can be compactly housed below (or below) the external output terminals 41 (or inclined surfaces 42) arranged "obliquely" ( For example, see FIGS. 6 and 8, especially FIG. 8).

With such a “diagonal” arrangement, in the secondary battery 40 (FIG. 6 (top)) of the present disclosure, the electrode assembly 45 is considerably connected to the inclined surface 42 or the external output terminal 41 arranged diagonally. Can be placed in close proximity. For example, the capacity (or volume) of the electrode assembly 45 can be increased by _{the distance D 2} as compared with the conventional secondary battery 140 (FIG. 6 (bottom)). As a result, the capacity of the electrode assembly 45 can be maximized, for example, and the capacity of the battery can be maximized while reducing the size of the entire secondary battery.

Hereinafter, the secondary battery according to the preferred embodiment of the present invention will be described, but before that, the “exterior body”, the “external output terminal”, the “electrode assembly” and the “current collector tab” will be described with reference to FIG. I will briefly explain the relationship between. It should be noted that these configurations are not limited to the following descriptions.

[Exterior body]
In the secondary battery of the present disclosure, the exterior body may be a flexible case having a laminated structure or the like, or a hard case having a non-laminated structure such as a metal exterior body. The exterior body is preferably a metal exterior body. For example, as shown in FIG. 7, as the exterior body 53, the metal exterior body may have a two-part configuration of, for example, a cup-shaped member 53a and a lid-shaped member 53b. The cup-shaped member 53a and the lid-shaped member 53b may be electrically connected. In that case, the entire exterior body including the cup-shaped member 53a and the lid-shaped member 53b can be treated as one large terminal. For example, it is preferable that the cup-shaped member 53a and the lid-shaped member 53b are electrically connected by any known means (for example, welding).

In the secondary battery of the present disclosure, it is preferable that the metal exterior body has a non-laminated structure. That is, in the present invention, the metal exterior body is not, for example, a laminated member of a metal sheet / fusion layer / protective layer. Preferably, the metal exterior has a structure composed of a single metal member. For example, the metal exterior body (each of the cup-shaped member 53a and the lid-shaped member 53b) may be a single member made of a metal such as stainless steel (SUS) or aluminum. The exterior body in the present disclosure may contain an alloy as a metal.
In the present disclosure, the term "single metal member" means that the exterior body does not have a so-called laminated structure in a broad sense, and in a narrow sense, the exterior body is a member substantially composed of only metal. It means that it has become. Therefore, an appropriate surface treatment may be applied to the surface of the metal exterior body as long as the member is substantially composed of only metal.

The metal exterior can have a relatively thin thickness. For example, the metal exterior body in the present invention may have a thickness dimension of 50 μm or more and less than 200 μm, for example, 50 μm or more and 190 μm or less, 50 μm or more and 180 μm or less, or 50 μm or more and 170 μm or less.

[External output terminal]
In the secondary battery of the present disclosure, the external output terminal is a terminal for electrically connecting the electrode assembly and the outside (or the outside of the secondary battery), and specifically for connecting to an external device or the like. It is a terminal to be provided (in the present disclosure, it may also be referred to as an "external terminal", an "output terminal", or an "electrode terminal"). The external output terminal can be used without particular limitation as long as it is a terminal containing a conductive material. As the material having conductivity, metal is preferable, and for example, at least one selected from the group consisting of stainless steel (SUS), aluminum, nickel and copper may be used. The plan-view shape of the external output terminal is also not particularly limited, and may be a substantially rectangular shape including an arbitrary geometric shape, for example, a substantially quadrangle, or a substantially circular shape. Further, the surface of the metal may be appropriately surface-treated.

The external output terminal often has a rivet-type configuration, and may be provided, for example, by "caulking" a metal rivet member. In particular, when the exterior body is a metal exterior body, it is preferable to "crimp" the metal rivet member via an arbitrary "insulating member". In this case, because of "caulking", the metal rivet portion is deformed, and sealing can be achieved by pressing the insulating member. As the "insulating member", for example, a member including a resin material or an elastomer material can be used.
As the resin material, a thermoplastic resin, preferably a heat-sealing resin can be used. Examples of the thermoplastic resin include polyolefin resins such as polyethylene and / or polypropylene and copolymers thereof. As the insulating member, a single-layer film made of a thermoplastic resin or a multilayer film containing a thermoplastic resin can be used. As an example of the multilayer film, a multilayer heat-sealing film in which both sides of a high melting point resin layer to be an intermediate layer are sandwiched by a low melting point resin layer (thermoplastic resin layer) can be mentioned. Further, examples of the elastomer material include polyester-based thermoplastic elastomers.

More specifically, as shown in FIG. 7, the external output terminal 51 is a metal rivet on an inclined surface 52 provided on the peripheral edge of the exterior body 53 (specifically, the cup-shaped member 53a) via the insulating member 56. It can be provided by "caulking" the member.

The external output terminal may be a metal plate. The metal plate may have a plurality of layers made of different metal materials.

For example, when a metal exterior body is used as the exterior body, the external output terminal 51 may be one of the positive electrode and the negative electrode, and the metal exterior body may be the other of the positive electrode and the negative electrode. As a result, the number of parts of the secondary battery can be reduced.

For example, the positive electrode side of the secondary battery is provided in the external output terminal 51, while the negative electrode side of the secondary battery can be provided in any region of the metal exterior 53. That is, the external output terminal 51 may be adopted only on the positive electrode side, and the negative electrode side may be connected from any place of the metal exterior body 53. Assuming that the one that outputs using the external output terminal is the positive electrode, the metal exterior body 53 is the negative electrode. Therefore, as a lithium ion battery whose negative electrode area is designed to be larger than that of the positive electrode, the possibility of causing a large short circuit can be reduced even if the electrode comes into contact with the can interior. Further, since it is only necessary to electrically connect the negative electrode to the exterior body, the production thereof becomes simple.

[Electrode assembly]
As shown in the schematic view of FIG. 7, in the secondary battery 50 of the present disclosure, since the external output terminal 51 can be arranged “diagonally”, the electrode assembly 55 has an inclined surface 52 or an external output terminal arranged obliquely. It can be arranged closer to the 51. With such a configuration, in the secondary battery 50, as described above, the capacity of the electrode assembly 55 in the exterior body 53 can be made larger, for example, maximized while the entire secondary battery is miniaturized.

The space S ₅₀ of the lower (or bottom) of the external output terminal 51 disposed in the "oblique" in the exterior body 53 via the inclined surface 52, as described above, current collection can extend from the electrode assembly 55 The tab 54 (specifically, the positive electrode current collecting tab 54a and / or the negative electrode current collecting tab 54b) can be accommodated more compactly.

In the secondary battery 50, it is preferable that the electrodes of the electrode assembly 55 include a positive electrode and a negative electrode capable of occluding and releasing lithium ions.

[Current collector tab]
As shown in the schematic diagram of FIG. 7, in the space S ₅₀ of the outer body 53 (more specifically cup 53a), the collector tab 54 (specifically may extend from the electrode assembly 55 positive current The electric tab 54a and / or the negative electrode current collecting tab 54b) can be successfully accommodated (eg, FIG. 8). It is preferable that the electrode assembly 55 includes a positive electrode and a negative electrode, the positive electrode includes a positive electrode current collecting tab 54a, and the negative electrode includes a negative electrode current collecting tab 54b.

It is preferable that the positive electrode current collecting tab 54a is connected to the external output terminal 51. Further, it is preferable that the negative electrode current collecting tab 54b is directly connected to the exterior body (specifically, the lid-shaped member 53b of the metal exterior body).

<Secondary battery according to a preferred embodiment of the present invention>
Finally, FIG. 8 shows a secondary battery 50 according to a preferred embodiment of the present invention. The secondary battery 50 includes at least an external output terminal 51, an exterior body 53, and an electrode assembly 55 in which an electrode constituent layer 5'is laminated.
The exterior body 53 is a metal exterior body, and the metal exterior body has a two-part configuration of a cup-shaped member 53a and a lid-shaped member 53b. The cup-shaped member 53a and the lid-shaped member 53b are electrically connected to each other by welding.
The external output terminal 51 is provided on the inclined surface 52 of the cup-shaped member 53a via the insulating member 56.
In the present disclosure, the "cup-shaped member" has a side surface portion corresponding to a body portion and a main surface portion (for example, an upper surface) continuous thereto, and a hollow portion is formed inside. It means a member.
In the present disclosure, the "lid-shaped member" means a member provided so as to cover such a cup-shaped member. The lid-shaped member may be, for example, a single member (typically a flat plate-shaped member) extending in the same plane. In the exterior body, the lid-shaped member and the cup-shaped member may be arbitrarily combined so that the lid-shaped member and the lower end portion of the cup-shaped member engage, connect, or fit with each other.
The electrode constituent layer 5'contains a positive electrode 1', a negative electrode 2', and a separator 3'.
The positive electrode 1'and the negative electrode 2'contain the positive electrode current collector and the negative electrode current collector in a sandwich shape, respectively. A positive electrode current collector tab 54a and a negative electrode current collector tab 54b, in which protruding portions of the positive electrode current collector and the negative electrode current collector are integrated on the tip side, extend from the electrode assembly 55, respectively. Here, the positive electrode current collector and the positive electrode current collector tab 54a are preferably integrally formed of the same conductive material. Similarly, the negative electrode current collector and the negative electrode current collector tab 54b are preferably integrally formed of the same conductive material.
The positive electrode current collecting tab 54a is preferably assembled by a conventionally known method and electrically connected to the external output terminal 51. Therefore, the external output terminal 51 can function as a positive electrode terminal.
The negative electrode current collecting tab 54b is preferably assembled by a conventionally known method and electrically connected to the lid-shaped member 53b of the metal exterior body. Here, as shown in FIG. 8, the negative electrode current collecting tab 54b is in contact with the lid-shaped member 53b and extends. Therefore, the lid-shaped member 53b, and thus the entire metal exterior body 55, can function as the negative electrode terminal.

The secondary battery 50 shown in FIG. 8 has a configuration in which the external output terminals 51 are arranged “diagonally” with respect to the main surface (specifically, the upper surface, the lower surface, more specifically, the upper surface) of the exterior body 53. More specifically, it has a configuration in which the external output terminals 51 are arranged "obliquely" via the inclined surface 52. In the secondary battery 50 having such a configuration, since the external output terminal 51 can be arranged in the dead space of the exterior body of the conventional secondary battery, such dead space can be effectively used (for example, FIG. 4). Further, a protection circuit or the like can be arranged in the dead space of the exterior body of the conventional secondary battery via the inclined surface 52, specifically, on the upper side or the lower side of the inclined surface 52, and the space can be used more effectively. can do.

Further, in the secondary battery 50, a current collector that can extend from the electrode assembly 55 to _{a space (or space) S 50} (for example, FIG. 7) below (or below) the external output terminal 51 (or the inclined surface 52). The tabs 54 (specifically, both the positive electrode current collecting tab 54a and the negative electrode current collecting tab 54b) can be accommodated successfully and efficiently. As a result, the electrode assembly 55 can be arranged closer to the external output terminal 51 or the inclined surface 52, and the capacity of the electrode assembly, and thus the capacity of the battery, can be increased while making the entire secondary battery smaller. , For example, can be maximized.

In the secondary battery 50, since the external output terminal 51 (specifically, the positive electrode terminal) is arranged “diagonally” and more specifically on the “inclined surface 52”, the battery The positive electrode and / or the negative electrode can be clearly discriminated or identified visually. Further, since the entire exterior body 53 is a negative electrode terminal, any surface of the exterior body can be electrically contacted (or contacted) as a negative electrode.

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

For example, although the above mainly touched on button-shaped (or coin-shaped) and polygonal secondary batteries, the present invention is not necessarily limited to these. That is, the secondary battery of the present disclosure is not limited to a circular or square shape in a plan view, and may have any other geometric shape. Similarly, the shape of the external output terminal (particularly the plan view shape) is not necessarily limited to a shape such as a substantially quadrangle or a substantially rectangular shape, and may have another geometric shape such as a substantially circular shape.
The term "circular or substantially circular" as used herein is not limited to a perfect circular shape (that is, simply a "circle" or a "perfect circle"), but is usually changed to a "round shape" as recognized by those skilled in the art. It also includes shapes that can be included. For example, not only a circle and a perfect circle, but also the curvature of the arc may be locally different, and further, a shape derived from a circle and a perfect circle such as an ellipse may be used.

The secondary battery according to the embodiment of the present invention can be used in various fields where storage can be expected. Although only an example, the secondary battery according to the embodiment of the present invention includes electric / information / communication fields (for example, mobile phones, smartphones, laptop computers and digital cameras, activities) in which electric / electronic devices can be used. Electric / electronic equipment field or mobile equipment field including meter, arm computer, electronic paper, wearable device, RFID tag, card type electronic money, small electronic device such as smart watch), home / small industrial application (for example, electric) Tools, golf carts, home / nursing / industrial robots), large industrial applications (eg forklifts, elevators, bay port cranes), transportation systems (eg hybrids, electrics, buses, trains) , Electric assisted bicycles, electric motorcycles, etc.), power system applications (for example, various power generation, road conditioners, smart grids, general household installation type power storage systems, etc.), medical applications (medical equipment fields such as earphone hearing aids) , Pharmaceutical applications (fields such as dose management systems), IoT fields, space / deep sea applications (for example, fields such as space probes and submersible research vessels) and the like.

1,1'Positive 2,2' Negative 3,3' Separator 5,5' Electrode constituent layer 10

Electrode assembly

20, 30, 40, 50, 100, 140, 200

Secondary battery

21, 31, 41, 51, 101,141,201

External output terminals

22,32,42,52

Inclined surfaces

23,33,43,53,103,143,203 Exterior bodies 44,54,104,144,204 Current collection tabs 45,55,105, 145,205 Electrode assembly 56 Insulation member S ₄₀ , S ₅₀ Space
S ₁₀₀ , S ₁₄₀ , S ₂₀₀ Dead space E Periphery (edge)

Claims

A secondary battery including an electrode assembly, an exterior body for accommodating the electrode assembly, and an external output terminal for electrically connecting the electrode assembly to the outside.
The electrode assembly comprises a positive electrode and a negative electrode, the positive electrode comprises a positive electrode current collecting tab, and the negative electrode comprises a negative electrode current collecting tab.
At least one of the positive electrode current collecting tab and the negative electrode current collecting tab is connected to the external output terminal.
A secondary battery in which the external output terminal is provided obliquely with respect to at least one flat exterior main surface of the exterior body.
The secondary battery according to claim 1, wherein the exterior body has an inclined surface, and the external output terminal is provided on the inclined surface.
The secondary battery according to claim 2, wherein the inclined surface is positioned at least a part of the peripheral edge of the exterior body in a plan view.
The secondary battery according to any one of claims 1 to 3, wherein the flat exterior main surface is at least one of an upper surface and a lower surface facing each other in the thickness direction of the exterior body.
The secondary battery according to any one of claims 1 to 4, wherein the positive electrode current collecting tab and / or the negative electrode current collecting tab is arranged below the diagonally provided external output terminal.
The secondary battery according to any one of claims 1 to 5, wherein the external output terminal is one terminal of a positive electrode and a negative electrode, and the exterior body forms the other terminal of the positive electrode and the negative electrode.
The secondary battery according to any one of claims 1 to 6, wherein the positive electrode current collecting tab is connected to the external output terminal, and the negative electrode current collecting tab is directly or indirectly connected to the exterior body. ..
The secondary battery according to any one of claims 1 to 7, wherein the external output terminal is attached to the exterior body via an insulating member.
The secondary battery according to any one of claims 1 to 8, wherein the exterior body is a metal exterior body, and the metal exterior body has a two-part configuration of a cup-shaped member and a lid-shaped member.
The secondary battery according to any one of claims 1 to 9, wherein the electrode of the electrode assembly includes a positive electrode and a negative electrode capable of storing and releasing lithium ions.