Patent Application
20230207988
The present invention relates to a secondary battery and a method for manufacturing the secondary battery. Particularly, the present invention relates to a secondary battery including an electrode assembly composed of electrode-constituting layers including a positive electrode, a negative electrode, and a separator.
Secondary batteries can be repeatedly charged and discharged, and are used in various applications. For example, secondary batteries are used for mobile devices such as mobile phones, smart phones and notebook computers. Further, such secondary batteries are disclosed in Patent Document 1 and Patent Document 2.
The inventors of the present application have noticed that the conventional secondary batteries have problems to be overcome, and have found a need to take measures therefor. Specifically, the inventors of the present application have found that the batteries have the following problems.
Patent Literature 1 discloses a secondary battery in which an electrode group housed in a battery container and a lid unit are connected with a lead plate interposed therebetween. In the process of for manufacturing the secondary battery, it is conceivable to increase the length of the lead plate from the viewpoints such as facilitating the electrical connection between the lead plate and the lid unit. In this case, however, it has not been easy to seal the lid unit while the lead plate is housed in the battery container. In addition, in housing the lead plate in the battery container, a load may be applied to the lid unit and/or the electrode group.
The present invention has been made in view of such problems. More specifically a main object of the present invention to provide a secondary battery that has a reduced load applied to a lead, and a method for manufacturing the secondary battery.
A secondary battery according to the present invention includes: an exterior body defining an internal space; an electrode assembly in the internal space of the exterior body; a terminal member electrically connected to the electrode assembly; a lead that electrically connects the terminal member and the electrode assembly; and a fixing member that fixes the lead to an inner surface of the exterior body.
In addition, a manufacturing method according to the present invention includes: electrically connecting a lead that is electrically connected to an electrode assembly within an interior space of an exterior body to a terminal member; and fixing the lead to an inner surface of the exterior body with a fixing member.
In the secondary battery according to the present invention, since the lead electrically connecting the terminal member and the electrode assembly is fixed to the inner surface of the exterior body, the lead fixed can be housed in the exterior body, and a load applied to the lead can be thus reduced. In addition, the method for manufacturing a secondary battery according to the present invention includes the step of fixing the lead to the inner surface of the exterior body, thus allowing the manufacture of a secondary battery in which a lead can be easily housed in an exterior body.
Hereinafter, a secondary battery according to an embodiment of the present invention will be described in more detail. Although the description will be made with reference to the drawings as necessary, various elements in the drawings are merely schematically and exemplarily shown for understanding of the present invention, and the appearance, the dimensional ratio, or the like can be different from those of an actual secondary battery.
The “vertical direction” and “horizontal direction” described directly or indirectly in this specification correspond to the vertical direction and horizontal direction in the drawings. Unless otherwise specified, the same reference signs or symbols denote the same members or sites, or the same semantic contents. In addition, the “sectional view” described directly or indirectly in the present specification is based on a virtual section obtained by cutting the secondary battery along the vertical direction of the electrode assembly or the electrode-constituting layer constituting the secondary battery. Similarly, the direction of a “thickness” described directly or indirectly in the present specification is based on the “vertical direction” of the electrode materials constituting the secondary battery. For example, in the case of a “secondary battery that has a thickness in a plate shape” such as a button type or a coin type, the direction of the “thickness” corresponds to the plate thickness direction of the secondary battery. The term “planar view” used in the present specification is based on a sketch drawing of an object viewed from above or below in the thickness direction. Unless otherwise specified, the same reference signs or symbols denote the same members or sites, or the same semantic contents.
The term “upper surface” used in the present specification means a surface positioned on the upper side in the vertical direction among surfaces constituting the battery, and the term “lower surface” means a surface positioned on the lower side in the vertical direction among the surfaces constituting the battery. Assuming such a typical secondary battery that has two opposed main surfaces, the term “upper surface “used in the present specification refers to one of the main surfaces, and the term “lower surface” refers to the other of the main surfaces.
[Basic Configuration of Secondary Battery]
The term “secondary battery” as used in the present specification refers to a battery that can be repeatedly charged and discharged. Accordingly, the secondary battery according to the present invention is not excessively limited by its name, and for example, an “electric storage device and the like can also be included in the subject of the present invention.
The secondary battery according to the present invention has an electrode assembly including electrode-constituting layers including a positive electrode, a negative electrode, and a separator.
The positive electrode 1 is composed of at least a positive electrode material layer and a positive electrode current collector. For the positive electrode, the positive electrode material layer is provided on at least one side of the positive electrode current collector, and the positive electrode material layer includes a positive electrode active material as an electrode active material. For example, for the plurality of positive electrodes in the electrode assembly, for each of the electrodes, the positive electrode material layer may be provided on both sides of the positive electrode current collector, or may be provided only on one side of the positive electrode current collector.
The negative electrode 2 is composed of at least a negative electrode material layer and a negative electrode current collector. For the negative electrode, the negative electrode material layer is provided on at least one side of the negative electrode current collector, and the negative electrode material layer includes a negative electrode active material as an electrode active material. For example, for the plurality of negative electrodes in the electrode assembly, for each of the electrodes, the negative electrode material layer may be provided on both sides of the negative electrode current collector, or may be provided only on one surface of the negative electrode current collector.
The electrode active materials included in the positive electrode 1 and the negative electrode 2, that is, the positive electrode active material and the negative electrode active material are substances directly involved in the transfer of electrons in the secondary battery, and are main substances of the positive and negative electrodes, which are responsible for charge-discharge, that is, a battery reaction. More specifically, ions are brought into the electrolyte due to “the positive electrode active material included in the positive electrode material layer” and “the negative electrode active material included in the negative electrode material layer”, and such ions move between the positive electrode and the negative electrode to transfer electrons, thereby leading to charge-discharge. The positive electrode material layer and the negative electrode material layer may be layers particularly capable of occluding and releasing lithium ions. More specifically, the secondary battery according to the present invention may be a nonaqueous electrolyte secondary battery in which lithium ions move between the positive electrode and the negative electrode through a nonaqueous electrolyte, thereby charging and discharging the battery. When lithium ions are involved in charge-discharge, the secondary battery according to the present invention corresponds to a so-called “lithium ion battery”, and the positive electrode and the negative electrode include a layer capable of occluding and releasing lithium ions.
When the positive electrode active material of the positive electrode material layer is composed of, for example, a granular material, a binder may be included in the positive electrode material layer for more sufficient contact between the particles and shape retention. Furthermore, a conductive auxiliary agent may be included in the positive electrode material layer to facilitate the transfer of electrons promoting a battery reaction. Similarly, when the negative electrode active material of the negative electrode material layer is composed of, for example, a granular material, a binder may be included for more sufficient contact between the particles and shape retention, and a conductive auxiliary agent may be included in the negative electrode material layer to facilitate the transfer of electrons promoting a battery reaction. As described above, the positive electrode material layer and the negative electrode material layer can, because of containing the multiple components, also be referred to respectively as a “positive electrode mixture layer” and a “negative electrode mixture layer”.
The positive electrode active material may be a material that contributes to occlusion and release of lithium ions. From such a viewpoint, 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 a group consisting of cobalt, nickel, manganese, and iron. More specifically, in the positive electrode material layer of the secondary battery according to the present invention, such a lithium-transition metal composite oxide is preferably included 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 material obtained by replacing a part of the transition metals with another metal. Such a positive electrode active material may be included as a single species, or two or more species may be included in combination.
The binder that can be included in the positive electrode material layer is not particularly limited, and examples thereof include at least one selected from the group consisting of a polyvinylidene fluoride, a vinylidene fluoride-hexafluoropropylene copolymer, a vinylidene fluoride-tetrafluoroethylene copolymer, and a polytetrafluoroethylene. The conductive auxiliary agent that can be included in the positive electrode material layer is not particularly limited, and examples thereof include at least one selected from carbon black such as thermal black, furnace black, channel black, ketjen black, and acetylene black, carbon fibers such as graphite, carbon nanotubes, and vapor-grown carbon fibers, metal powders such as copper, nickel, aluminum, and silver, and polyphenylene derivatives.
The thickness dimension of the positive electrode material layer is not particularly limited, and may be 1 μm to 300 μm, and is, for example, 5 μm to 200 μm. The thickness dimension of the positive electrode material layer is a thickness inside the secondary battery, and the average value of measured values at random 10 points may be employed.
The negative electrode active material may be a material that contributes to occlusion and release of lithium ions. From such a viewpoint, the negative electrode active material may be, for example, various carbon materials, oxides, and/or lithium alloys.
Examples of the various carbon materials for the negative electrode active material include graphite (natural graphite and artificial graphite), hard carbon, soft carbon, and diamond-like carbon. Particularly, graphite has high electron conductivity and excellent adhesiveness to the negative electrode current collector. Examples of the oxides for the negative electrode active material include at least one selected from the group consisting of a silicon oxide, a tin oxide, an indium oxide, a zinc oxide, and a lithium oxide. The lithium alloys for the negative electrode active material may be any metal that can be alloyed with lithium, and may be, for example, a binary, ternary, or higher alloy of lithium and a metal such as Al, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, Zn, and La. Such an oxide may be amorphous as its structural form. This is because deterioration due to nonuniformity such as grain boundaries or defects is less likely to be caused.
The binder that can be included in the negative electrode material layer is not particularly limited, and examples thereof include at least one selected from the group consisting of a styrene butadiene rubber, a polyacrylic acid, a polyvinylidene fluoride, a polyimide-based resin, and a polyamideimide-based resin. For example, the binder included in the negative electrode material layer may be a styrene-butadiene rubber. The conductive auxiliary agent that can be included in the negative electrode material layer is not particularly limited, and examples thereof include at least one selected from carbon black such as thermal black, furnace black, channel black, ketjen black, and acetylene black, carbon fibers such as graphite, carbon nanotubes, and vapor-grown carbon fibers, metal powders such as copper, nickel, aluminum, and silver, and polyphenylene derivatives. It is to be noted that the negative electrode material layer may include therein a component derived from a thickener component (for example, a carboxymethyl cellulose) used at the time of manufacturing the battery.
The thickness dimension of the negative electrode material layer is not particularly limited, and may be 1 μm to 300 μm, and is, for example, 5 μm to 200 μm. The thickness dimension of the negative electrode material layer is a thickness inside the secondary battery, and the average value of measured values at random 10 points may be employed.
The positive electrode current collector and the negative electrode current collector used for the positive electrode and the negative electrode are members that contribute to collecting and supplying electrons generated in the electrode active material by the battery reaction. Such an electrode current collector may be a sheet-like metal member. In addition, such an electrode current collector may have a porous or perforated form. For example, the current collector may be a metal foil, a punching metal, a net, an expanded metal, or the like. The positive electrode current collector used for the positive electrode is preferably made of a metal foil containing at least one selected from the group consisting of aluminum, stainless steel, and nickel, and may be, for example, an aluminum foil. In contrast, the negative electrode current collector used for the negative electrode is preferably made of a metal foil containing at least one selected from the group consisting of copper, stainless steel, and nickel, and may be, for example, a copper foil. It is to be noted that the term “stainless steel” in the present specification refers to, for example, the stainless steel defined in “JIS G 0203 Glossary of terms used in iron and steel”, which may be an alloy steel containing chromium or containing chromium and nickel.
The thickness dimension of each of the positive electrode current collector and the negative electrode current collector is not particularly limited, and may be 1 μm to 100 μm, and is, for example, 10 μm to 70 μm. The thickness dimension of each of the positive electrode current collector and the negative electrode current collector is a thickness inside the secondary battery, and the average value of measured values at random 10 points may be employed.
The separator 3 used for the positive electrode and the negative electrode is a member provided from viewpoints such as preventing a short circuit due to contact between the positive and negative electrodes and holding the electrolyte. In other words, the separator can be considered as 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, which may have the form of a membrane to the small thickness. By way of example only, a microporous membrane made of a polyolefin may be used as the separator. In this respect, the microporous membrane for use as the separator may include, for example, only a polyethylene (PE) or only a polypropylene (PP) as the polyolefin. Furthermore, the separator may be a laminate 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 coating layer, and/or an adhesive layer. The surface of the separator may have adhesiveness. Further, in the present invention, the separator is not to be particularly limited by its name, and may be solid electrolytes, gel electrolytes, and/or insulating inorganic particles that have a similar function.
The thickness dimension of the separator is not particularly limited, and may be 1 μm to 100 μm, and is, for example, 2 μm to 20 μm. The thickness dimension of the separator is a thickness inside the secondary battery (particularly, the thickness between the positive electrode and the negative electrode), and the average value of measured values at random 10 points may be employed.
For the secondary battery according to the present invention, the electrode assembly 10 composed of the electrode-constituting layers 5 including the positive electrode 1, the negative electrode 2, and the separator 3 may be enclosed together with an electrolyte in an exterior body. The electrolyte can assist the movement of metal ions released from the electrodes (positive electrode and/or negative electrode). The electrolyte may be a “nonaqueous” electrolyte, such as an organic electrolyte and an organic solvent, or may be an “aqueous” electrolyte containing water. When the positive electrode and the negative electrode have a layer capable of occluding and releasing lithium ions, the electrolyte is preferably a “nonaqueous” electrolyte containing an organic electrolyte and/or an organic solvent, or the like. More specifically, the electrolyte preferably serves as a nonaqueous electrolyte. In the electrolyte, metal ions released from the electrodes (positive electrode and/or negative electrode) will be present, and the electrolyte will thus assist the movement of the metal ions in the battery reaction. It is to be noted that the electrolyte may have a form such as a liquid form or a gel form.
The nonaqueous electrolyte is an electrolyte including a solvent and a solute. A specific solvent for the nonaqueous electrolyte may contain at least a carbonate. Such carbonates may be cyclic carbonates and/or chain carbonates. Although not particularly limited, examples of the cyclic carbonates include at least one selected from the group consisting of a propylene carbonate (PC), an ethylene carbonate (EC), a butylene carbonate (BC), and a vinylene carbonate (VC). Examples of the chain carbonates include at least one selected from the group consisting of a dimethyl carbonate (DMC), a diethyl carbonate (DEC), an ethyl methyl carbonate (EMC), and a dipropyl carbonate (DPC). By way of an example only, combinations of cyclic carbonates and chain carbonates may be used as the nonaqueous electrolyte, and for example, a mixture of an ethylene carbonate and a diethyl carbonate may be used. As a specific solute for the nonaqueous electrolyte, for example, Li salts such as LiPF6 and/or LiBF4 may be used.
The exterior body 50 of the secondary battery is a member capable of housing or enclosing the electrode assembly 10 including the electrode-constituting layers 5 including the positive electrode 1, the negative electrode 2, and the separator 3. As will be described later, in the present invention, the exterior body 50 may be a metal exterior body that has a non-laminate configuration.
[Feature of Secondary Battery According to Present Invention]
The secondary battery 100 according to the present invention includes the electrode assembly 10 described above, the exterior body 50 that has a space for housing the electrode assembly 10 therein, a terminal member 60 electrically connected to the electrode assembly 10, and a lead 40 for electrically connecting the terminal member 60 and the electrode assembly 10 (see
The electrode assembly 10 according to the present embodiment may have the wound-type structure described above with reference to
The exterior body 50 may be a metal exterior body that has a non-laminate configuration. In such a case, the exterior body 50 is not a laminate member including a metal sheet, a fusion layer, and a protective layer. More specifically, the exterior body 50 has a non-laminate configuration. The metal exterior body that has the non-laminate configuration preferably has a configuration including a single metal member. For example, such a metal exterior body may be a single member made of a metal such as stainless steel (SUS) and/or aluminum. The term “single metal member” as used herein means that the exterior body 50 has no so-called laminate configuration in a broad sense, and means that the exterior body 50 is a member substantially made of only a metal in a narrow sense. Thus, as long as the metal exterior body is a member substantially made of only a metal, the surface of the metal exterior body may be subjected to an appropriate surface treatment.
From the viewpoint of easily housing the electrode assembly 10, the exterior body 50 may include a first exterior body 54, which is a lid-shaped member, and a second exterior body 56, which is a cup-shaped member, as in the preferred embodiment illustrated in
The first exterior body 54 as a lid-shaped member may have, at the center thereof, an opening 54a formed. Further, the terminal member 60 may be provided so as to cover the opening 54a. An insulating material 70 may be disposed between the terminal member 60 and the first exterior body 54.
The insulating material 70 is provided so as to fill the gap between the first exterior body 54 and the terminal member 60, and it can be thus understood that the insulating material 70 contributes to “sealing”. As illustrated in
The terminal member 60 means, in the secondary battery, an output terminal provided for connection to an external device. The terminal member 60 has the form of, for example, a flat plate shape. The flat plate-shaped terminal member 60 may be, for example, a metal plate. The material of the terminal member 60 is not particularly limited, and may contain at least one metal selected from the group consisting of aluminum, nickel, and copper. As can be seen from the preferred embodiment illustrated in
The second exterior body 56 as a cup-shaped member has a housing space for housing the electrode assembly 10, and the above-described electrode assembly 10 may be housed in the housing space. In the preferred embodiment illustrated in
The lead 40 drawn out from the electrode assembly 10 is fixed to the inner surface of the exterior body 50. In this regard, the “inner surface of the exterior body” in the present specification means a surface of the exterior body that is not exposed to the outside in the finished secondary battery. In addition, the term “fixed” in the present specification means that the lead is attached so as not to move with respect to a predetermined position of the exterior body. For example, in the preferred embodiment illustrated in
Furthermore, the upper-surface lead 41 is also fixed to the terminal member 60 in addition to the first exterior body 54, and the fixing strength can be thus enhanced as compared with a conventionally known “secondary battery including a lead connected to only tan external electrode”.
In addition, in the case of a conventionally known “secondary battery including a lead connected to only an external electrode”, if the lead is large in length, the frequency of folding is increased in housing the lead inside an exterior body, thereby causing the lead complicated to have complicated routing. In contrast, in the preferred embodiment of the present invention (see
Furthermore, in a conventionally known “secondary battery including a lead connected to only an external electrode”, if the exterior is cleaved by the abnormally increased internal pressure of the exterior body, the external electrode may be detached from the lead and then scattered to the environment. In contrast, in the preferred embodiment of the present invention (see
The lead may be fixed with a fixing member. In the preferred embodiment illustrated in
The fixing member 80 used for fixing the lead is preferably a member that provides adhesiveness between the exterior body and the lead. In the present specification, the term “adhesiveness” means a property that peeling is unlikely to be caused after bonding. Examples of the fixing member 80 include an adhesive containing a polyethylene and/or a polypropylene, an olefin-based adhesive, a resin-based adhesive, and a hot-melt adhesive. The fixing method with the fixing member 80 used can achieve more firmly fixing than the fixing by crimping or welding.
The fixing strength between the upper-surface lead 41 and the first exterior body 54 may be higher than the connection strength between the terminal member 60 and the upper-surface lead 41. More specifically, the fixing between the terminal member 60 fixed with the fixing member 80 used and the first exterior body 54 may be higher than the connection strength between the upper-surface lead 41 and fixing member 80 electrically connected by laser welding or the like as described above. In this regard, in the present specification, the “connection strength” means an index that indicates how much strength peels off members when the members are connected to each other. With such fixing, if the internal pressure of the exterior body is abnormally increased, the first exterior body 54 and the terminal member 60 can be kept from being detached from the lead and scattered to the environment, because the first exterior body 54 and the upper-surface lead 41 are firmly fixed to each other.
Furthermore, the fixing member 80 is preferably a member that has an insulating property. In the present specification, the term “insulating property” is a property that makes a current unlikely to flow, and means the range of 106 Ω·m or more in terms of resistivity. In the preferred embodiment illustrated in
Next, additional aspects of fixing the lead will be described.
The lead may be folded and housed in the exterior body. More specifically, in the preferred embodiment illustrated in
In the preferred embodiment illustrated in
In the preferred embodiment illustrated in
In the preferred embodiment illustrated in
In the preferred embodiment illustrated in
In the preferred embodiment illustrated in
In the preferred embodiment illustrated in
Further, according to this aspect, the overall shape of the secondary battery in a planar view is a substantially circular shape. More specifically, the secondary battery 100 has a button type or a coin type in terms of outer shape (refer to
Next, another embodiment of the present invention will be described with reference to
An electrode assembly 10 according to the present embodiment may have the stacked-type structure described above with reference to
Further, in the preferred embodiment illustrated in
Next, another embodiment of the present invention will be described with reference to
In the preferred embodiment illustrated in
In the preferred embodiment illustrated in
[Feature of Method for Manufacturing Secondary Battery According to Present Invention]
Next, a method for manufacturing the secondary battery according to the present invention will be described with reference to
First, an electrode assembly 10 is manufactured by stacking or winding electrode-constituting layers including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and drawing leads electrically connected respectively to the positive electrode and the negative electrode. According to the present embodiment, the upper-surface lead 41 may be drawn out toward the upper surface of the electrode assembly, and the lower-surface lead 42 may be drawn out toward the lower surface thereof. Then, an electrolyte is housed together with the manufactured electrode assembly 10 in a second exterior body 56, which is a cup-shaped member (see
Next, a sealing structure for sealing the upper surface of the second exterior body 56 is prepared. The sealing structure for use in the present embodiment may include: a first exterior body 54 with an opening 54a; a terminal member 60 that covers the opening 54a and acts as an external terminal; and an insulating material 70 with insulating and adhesive properties, provided so as to fill the gap between the terminal member 60 and the first exterior body 54. More specifically, the terminal member 60 may be bonded to the first exterior body 54 with adhesive the insulating material 70. In this manner, the sealing structure for sealing the upper surface of the second exterior body 56 is manufactured.
Next, the lead electrically connected to the electrode assembly is electrically connected to the terminal member. In the preferred embodiment illustrated in
Next, the lead is fixed to the inner surface of the exterior body. In the preferred embodiment illustrated in
In addition, the position of the fixing member 80 provided is preferably close to the opening 54a of the first exterior body 54. More specifically, as illustrated in
In addition, the fixing between the terminal member 60 fixed with the fixing member 80 used and the first exterior body 54 may be higher than the connection strength between the upper-surface lead 41 and fixing member 80 electrically connected by laser welding or the like as described above. With such fixing, if the internal pressure of the exterior body is abnormally increased, the first exterior body 54 and the terminal member 60 can be kept from being detached from the lead and scattered to the environment, because the first exterior body 54 and the upper-surface lead 41 are firmly fixed to each other.
Next, as illustrated in
Then, the first exterior body 54 is mounted on the upper surface of the second exterior body 56, and the first exterior body 54 and the second exterior body 56 are attached to each other. The attachment may be performed by, for example, laser welding. It is to be noted that the approach for attaching the first exterior body 54 and the second exterior body 56 is not limited to laser welding, and for example, an adhesive may be used. For electrically connecting the first exterior body 54 and the second exterior body 56 to each other, a conductive adhesive may be used. In addition, for electrically insulating the first exterior body 54 and the second exterior body 56 from each other, an insulating adhesive may be used.
As described above, the method for manufacturing a secondary battery according to the present invention includes the connecting step of electrically connecting the lead electrically connected to the electrode assembly, to the terminal member, and the fixing step of fixing the lead to the inner surface of the exterior body. Then, the secondary battery manufactured according to the present embodiment has the lead fixed to the exterior body, thus allowing the load applied to the lead to be also distributed to the exterior body, and allowing the load to be reduced. The lead is also fixed to the terminal member in addition to the exterior body, thus allowing the fixing strength to be enhanced. Furthermore, the lead can be housed in the exterior body with the lead shortened by the amount fixed to the first exterior body, and the housing can be simplified. Further, the lead is positioned at an inner position of the exterior body so as not to hinder housing the lead, and then fixed, thereby allowing for facilitating the routing of the lead at the time of housing the lead. Furthermore, if the internal pressure of the exterior body is abnormally increased, the exterior body and the terminal member can be kept from being detached from the lead and scattered to the environment.
It is to be noted that embodiments disclosed herein are considered by way of illustration in all respects, and not considered as a basis for restrictive interpretations. Accordingly, the technical scope of the present invention is not to be construed only by the embodiments mentioned above, but is defined based on the description of the claims. In addition, the technical scope of the present invention encompasses meanings equivalent to the claims and all modifications within the scope of the claims.
The secondary battery according to the present invention can be used in various fields in which battery use or power storage is assumed. By way of example only, the secondary battery according to the present invention can be also used in the fields of electricity, information, and communication in which mobile devices and the like are used (for example, electric and electronic device fields or mobile device fields including mobile phones, smartphones, notebook computers and digital cameras, activity meters, arm computers, electronic paper, wearable devices, or small electronic machines such as RFID tags, card type electronic money, and smartwatches), home and small industrial applications (for example, the fields of electric tools, golf carts, and home, nursing, and industrial robots), large industrial applications (for example, the fields of forklift, elevator, and harbor crane), transportation system fields (for example, the fields of hybrid vehicles, electric vehicles, buses, trains, power-assisted bicycles, electric two-wheeled vehicles), power system applications (for example, the fields of various types of power generation, road conditioners, smart grids, and household power storage systems), medical applications (medical device fields such as earphone hearing aids), pharmaceutical applications (fields such as dosage management systems), IoT fields, space and deep sea applications (for example, the fields of a space probe and a submersible), and the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-142746 | Aug 2020 | JP | national |
The present application is a continuation of International application No. PCT/JP2021/027898, filed Jul. 28, 2021, which claims priority to Japanese Patent Application No. 2020-142746, filed Aug. 26, 2020, the entire contents of each of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP21/27898 | Jul 2021 | US |
| Child | 18173215 | US |
