WO2024257542A1 - Electrode plate, electrode body, and battery - Google Patents

Abstract

Disclosed is an electrode plate 21 comprising a band-like first core body 22 having a first main surface 23 and a second main surface 24, and active material layers 29 formed on the first main surface 23 and the second main surface 24. The first core body 22 has a double-sided exposure part 25 in which the active material layers 29 are not formed on the first main surface 23 and the second main surface 24. The double-sided exposure part 25 includes a first bonding region 25a to which a first lead 32 is bonded. At least one of the first main surface 23 and the second main surface 24 in the double-sided exposure part 25 is provided with a first identification display part 31 so that at least a part thereof overlaps with the first bonding region 25a in the thickness direction of the first core body 22. This makes it possible to avoid a decrease in the battery capacity due to the identification display part.

Description

Electrode plate, electrode body, and battery

The present disclosure relates to electrode plates, electrode bodies, and batteries.

　Technology for displaying information on an electrode plate provided in a battery is known (for example, Patent Document 1). The electrode plate in Patent Document 1 comprises a strip-shaped core body and active material layers formed on both sides of the core body, the core body having an exposed portion to which a current collecting lead is connected, and an identification display portion that can identify the manufacturing process history is formed in a position of the exposed portion different from the current collecting lead.

International Publication No. 2019/193869

However, although the identification marking needs to be provided in order to identify the history of the manufacturing process, an active material layer cannot be placed in the area where it is formed. In other words, the area where the identification marking is formed cannot effectively contribute to the development of battery capacity, and it can be said that the presence of the identification marking reduces the battery capacity. In this situation, one of the objectives of the present disclosure is to avoid the reduction in battery capacity due to the identification marking.

One aspect of the present disclosure relates to an electrode plate. The electrode plate includes a strip-shaped first core having a first main surface and a second main surface, and an active material layer formed on the first main surface and the second main surface, the first core having a double-sided exposed portion where the active material layer is not formed on the first main surface and the second main surface, the double-sided exposed portion including a first bonding region to which a first lead is bonded, and at least one of the first main surface and the second main surface of the double-sided exposed portion has a first identification display portion formed thereon so as to overlap at least a portion of the first bonding region in the thickness direction of the first core.

Another aspect of the present disclosure relates to an electrode assembly. The electrode assembly includes a first electrode plate and a second electrode plate wound with a separator interposed therebetween, and the first electrode plate is the electrode plate described above.

Another aspect of the present disclosure relates to a battery. The battery includes the above-mentioned electrode assembly and a bottomed cylindrical exterior can that contains the electrode assembly.

According to this disclosure, it is possible to avoid a decrease in battery capacity due to the identification display unit.

The novel features of the present invention are set forth in the appended claims, but the present invention, both in terms of structure and content, together with other objects and features of the present application, will be better understood from the following detailed description taken in conjunction with the drawings.

FIG. 1 is a longitudinal sectional view illustrating a schematic diagram of an example of a battery according to the present disclosure. FIG. 2 is a perspective view showing a schematic diagram of an example of an electrode body, in which the first and second leads are omitted. 3A and 3B are diagrams illustrating an example of a first electrode plate (electrode plate), in which FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along line III-III.

The following describes examples of embodiments of the electrode plate, electrode body, and battery according to the present disclosure. However, the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials may be given as examples, but other numerical values and materials may be applied as long as the effects of the present disclosure are obtained.

(Electrode plate)
The electrode plate according to the present disclosure includes a strip-shaped first core and an active material layer. In the following, an electrode plate used in a non-aqueous electrolyte secondary battery (e.g., a lithium ion secondary battery) will be described as an example, but the use of the electrode plate is not limited thereto. In the present disclosure, the category of secondary battery also includes an electricity storage device (e.g., a lithium ion capacitor) in which at least one of the positive electrode and the negative electrode is an electrode that exhibits capacity by a non-Faraday reaction.

The first core has a first main surface and a second main surface. When the electrode plate is used as a positive electrode plate, the first core may be a metal foil made of, for example, aluminum, an aluminum alloy, stainless steel, titanium, a titanium alloy, or the like. When the electrode plate is used as a negative electrode plate, the first core may be a metal foil made of, for example, copper, a copper alloy, nickel, a nickel alloy, or the like.

The active material layer is formed on the first and second principal surfaces of the first core. When the electrode plate is used as a positive electrode plate, the active material layer is a positive electrode active material layer, which may contain, in addition to the positive electrode active material, a conductive agent, a binder, a thickener, etc. When the electrode plate is used as a negative electrode plate, the active material layer is a negative electrode active material layer, which may contain, in addition to the negative electrode active material, a conductive agent, a binder, a thickener, etc.

As the positive electrode active material, for example, a composite metal oxide of lithium and a transition metal such as cobalt, manganese, or nickel can be used. The positive electrode active material may be used alone or in combination of two or more. As the negative electrode active material, for example, natural graphite, spherical or fibrous artificial graphite, non-graphitizable carbon (hard carbon), graphitizable carbon (soft carbon), and other carbon materials can be used.

As the conductive agent, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fiber and metal fiber, etc. can be used. As the conductive agent for the positive electrode, various graphites such as natural graphite and artificial graphite can be used.

The binder is not particularly limited as long as it can be dissolved or dispersed in the dispersion medium by kneading. Examples of the binder include fluororesin, rubbers, acrylic polymers or vinyl polymers (e.g., homopolymers or copolymers of monomers such as acrylic monomers such as methyl acrylate and acrylonitrile, and vinyl monomers such as vinyl acetate). Examples of the fluororesin include polyvinylidene fluoride, copolymers of vinylidene fluoride and propylene hexafluoride, and polytetrafluoroethylene. Examples of the rubber include acrylic rubber, modified acrylonitrile rubber, and styrene butadiene rubber (SBR). The binder may be used alone or in combination of two or more kinds. In general, fluororesin is preferred as the binder for the positive electrode, and fluororesin and rubbers are preferred as the binder for the negative electrode.

The first core has a double-sided exposed portion where no active material layer is formed on the first and second main surfaces. The double-sided exposed portion may be located midway along the length of the first core. The double-sided exposed portion includes a first bonding region to which the first lead is bonded. The first lead is a positive electrode lead when the electrode plate is used as a positive electrode plate, and is a negative electrode lead when the electrode plate is used as a negative electrode plate. The first bonding region is a region where the first core (double-sided exposed portion) and the first lead are bonded to each other (e.g., a region where the two are fused together), and is usually included inside the outline of the first lead when viewed from the thickness direction of the first core.

Here, it is difficult to provide an active material layer in the first bonding region, and also difficult to provide an active material layer in the region where the identification display part is formed. Therefore, normally, the first bonding region and the region where the identification display part is formed are each dead space from the viewpoint of battery capacity development. In contrast, in the electrode plate of the present disclosure, at least one of the first and second main surfaces in the both-side exposed portion has the first identification display part formed so as to overlap at least a portion with the first bonding region in the thickness direction of the first core body. In other words, as shown in FIG. 3(a), when viewed from the direction perpendicular to the paper surface of the figure, the first bonding region and the region where the first identification display part is formed at least partially overlap each other. This makes it possible to reduce the dead space from the above viewpoint and avoid a decrease in battery capacity.

The first identification display portion may be an identification display portion capable of identifying the history of the manufacturing process. The first identification display portion may be a QR code (registered trademark), which is a two-dimensional code, but is not limited to this. For example, the first identification display portion may be composed of numbers, letters, or a combination of numbers and letters, or may be composed of protrusions, holes, or a combination of protrusions and holes. The first identification display portion may also be a one-dimensional code such as a barcode. The first identification display portion may be formed, for example, by irradiating a laser onto the first main surface and/or the second main surface of the double-sided exposed portion.

The first core may further have a first double-sided coated section provided contiguous to one end of the double-sided exposed section in the longitudinal direction of the first core, with active material layers formed on the first and second main surfaces, and a second double-sided coated section provided contiguous to the other end of the double-sided exposed section in the longitudinal direction of the first core, with active material layers formed on the first and second main surfaces. In this configuration, the double-sided exposed section is sandwiched between the first double-sided coated section and the second double-sided coated section in the longitudinal direction of the first core. Since the first and second double-sided coated sections have a higher strength than the double-sided exposed section, deformation of the double-sided exposed section is suppressed when the first identification display section is formed on the double-sided exposed section. Therefore, the first identification display section can be formed on the double-sided exposed section with high accuracy. However, the first core may not have at least one of the first double-sided coated section and the second double-sided coated section.

The first core may further have a third double-sided coated section that is continuous with the double-sided exposed section in the width direction of the first core and has active material layers formed on the first and second main surfaces. With this configuration, the double-sided exposed section is reinforced from three directions by the first to third double-sided coated sections, making it even less susceptible to deformation. This allows the first identification marking to be formed on the double-sided exposed section with even greater precision. Furthermore, in the electrode plate according to the present disclosure, the area of the third double-sided coated section can be increased because the formation space for the third double-sided coated section is not narrowed by the first identification marking.

The first double-sided coated section, the second double-sided coated section, and the third double-sided coated section may be connected in the longitudinal direction of the first core body. In this configuration, the effect of reinforcing the double-sided exposed section is enhanced compared to when the first to third double-sided coated sections are not connected. Therefore, the first identification display section can be formed on the double-sided exposed section with even greater precision.

The electrode plate may further include a first lead joined to the first joining region. An electrode plate of this configuration may also be referred to as an "electrode plate assembly" in that it includes the first lead in addition to the electrode plate described above. However, in this specification, no clear distinction is made between the electrode plate and the electrode plate assembly, and both are referred to as "electrode plate" unless otherwise specified.

(Electrode body)
The electrode body according to the present disclosure includes a first electrode plate and a second electrode plate wound with a separator interposed therebetween. That is, the electrode body according to the present disclosure is a wound-type electrode body. The first electrode plate is the electrode plate described above. The first electrode plate may be a negative electrode plate or a positive electrode plate. The separator may be formed in a strip shape. The separator may be made of a polyolefin-based material or a porous film made by combining a polyolefin-based material with a heat-resistant material. Examples of the porous film made of a polyolefin-based material include porous films made of polyethylene, polypropylene, and ethylene-propylene copolymer. These resins may be used alone or in combination of two or more kinds. If necessary, other thermoplastic polymers may be used in combination with the polyolefin. Examples of the heat-resistant material include a heat-resistant resin and an inorganic filler. The porous film may be a single film or a multi-layer film. The multi-layer film may include a film of a mixture of a heat-resistant resin and an inorganic filler.

The second plate may include a strip-shaped second core having a second joint region to which the conductive member is joined. The second core may have a second identification display portion formed so as not to overlap the second joint region in the thickness direction of the second core. The conductive member may be made of metal, and may be, for example, a second lead joined to the main surface of the second plate, or a current collector plate joined to the end of the second plate. The conductive member may have a polarity different from that of the first lead. The second core may have a third main surface and a fourth main surface. The second joint region is a region where the second core and the conductive member are joined to each other (for example, a region where the two are fused together), and is usually included inside the outline of the conductive member when viewed from the thickness direction of the second core.

The second identification display portion may be an identification display portion capable of identifying the history of the manufacturing process. The second identification display portion may be a QR code (registered trademark) which is a two-dimensional code, but is not limited thereto. For example, the second identification display portion may be composed of numbers, letters, or a combination of numbers and letters, or may be composed of protrusions, holes, or a combination of protrusions and holes. The second identification display portion may also be a one-dimensional code such as a barcode. The second identification display portion may be formed, for example, by irradiating the third main surface and/or the fourth main surface of the second core body with a laser. The second identification display portion may or may not overlap the conductive member (e.g., the second lead) in the thickness direction of the second core body, as long as it does not overlap the second joint region.

The second identification display unit may be linked to the first identification display unit. In this configuration, information on not only the second plate but also the first plate can be checked via the second identification display unit. This is particularly useful because the first identification display unit may become unreadable after the first lead is joined to the first core. This linking may be achieved, for example, by registering information on the first and second identification display units in a specified terminal before winding the first and second plates through the separator.

(battery)
The battery according to the present disclosure includes the above-mentioned electrode assembly and a bottomed cylindrical exterior can that houses the electrode assembly. The exterior can may be, for example, a bottomed cylindrical shape or a bottomed rectangular tubular shape. The first core body or the second core body may be in contact with the inner surface of the exterior can. The exterior can may house a non-aqueous electrolyte together with the electrode assembly. The non-aqueous electrolyte may be prepared by dissolving a lithium salt in a non-aqueous solvent. Examples of non-aqueous solvents include cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate; chain carbonates such as dimethyl carbonate and diethyl carbonate; and lactones such as γ-butyrolactone. The non-aqueous solvents may be used alone or in combination of two or more.

Examples of the lithium salt include lithium salts having strong electron _- withdrawing properties, such as _LiPF6 , LiBF4, _LiClO4 , _LiAsF6 , _LiCF3SO3 , _LiN ( _{SO2CF3 ) 2} , LiN( _SO2C2F5 ) ₂ , and LiC( _{SO2CF3 ) 3} . The lithium salts can be used alone or in combination. _The concentration of the lithium salt in the non-aqueous electrolyte is, for example, 0.5 _to 1.5M, and preferably 0.7 to 1.2M.

The non-aqueous electrolyte may contain additives as appropriate. For example, vinylene carbonate (VC), cyclohexylbenzene (CHB), and modified forms of these may be used to form good films on the positive and negative electrodes. For example, terphenyl, cyclohexylbenzene, diphenyl ether, and the like may be used as additives that act when the non-aqueous electrolyte secondary battery is overcharged. The additives may be used alone or in combination of two or more kinds. The proportion of these additives is not particularly limited, but is, for example, about 0.05 to 10% by weight of the non-aqueous electrolyte.

As described above, according to the present disclosure, by arranging the first identification display part so that it overlaps at least partially with the first bonding region, it is possible to avoid a decrease in battery capacity due to the first identification display part. Furthermore, according to the present disclosure, by linking the first identification display part and the second identification display part to each other, it is possible to check information on the first and second plates only using the latter.

Below, an example of an electrode plate, electrode body, and battery according to the present disclosure will be specifically described with reference to the drawings. The above-mentioned components can be applied to the components of the electrode plate, electrode body, and battery of the example described below. The components of the electrode plate, electrode body, and battery of the example described below can be modified based on the above description. In addition, the matters described below may be applied to the above embodiment. Among the components of the electrode plate, electrode body, and battery of the example described below, components that are not essential for the electrode plate, electrode body, and battery according to the present disclosure may be omitted. Note that the diagrams shown below are schematic and do not accurately reflect the shape and number of actual members.

The battery 10 of this embodiment is configured as a lithium ion secondary battery, but is not limited to this. As shown in Figures 1 to 3, the battery 10 includes a wound electrode body 20, a cylindrical exterior can 40 with a bottom, and a sealing plate 50.

The electrode body 20 is formed by winding a band-shaped first electrode plate 21 and a second electrode plate 33 with a band-shaped separator 36 in between. The electrode body 20 is also provided with a pair of tapes 37 arranged near both ends in the width direction of the second electrode plate 33 (near the top and bottom ends in FIG. 2) and holding the electrode body 20 in a wound state. In this embodiment, the first electrode plate 21 is a positive electrode and the second electrode plate 33 is a negative electrode, but this is not limited to this. The second electrode plate 33 is exposed all around the outermost periphery of the electrode body 20, but this is not limited to this. At the outermost periphery of the electrode body 20, the second core body 34 (see FIG. 2) of the second electrode plate 33 is in contact with the inner surface of the outer can 40.

As shown in FIG. 3, the first electrode plate 21 comprises a strip-shaped first core body 22 having a first main surface 23 and a second main surface 24, a first active material layer 29 formed on the first main surface 23 and the second main surface 24, and a conductive first lead 32. In this embodiment, the first active material layer 29 is a positive electrode active material layer. The first electrode plate 21 is an example of an electrode plate, and the first active material layer 29 is an example of an active material layer.

The first core 22 has a double-sided exposed portion 25, a first double-sided coated portion 26, a second double-sided coated portion 27, and a third double-sided coated portion 28. The double-sided exposed portion 25 does not have a first active material layer 29 formed on the first main surface 23 and the second main surface 24. The first double-sided coated portion 26 is provided continuously at one end (left end in FIG. 3(a)) of the double-sided exposed portion 25 in the longitudinal direction (left-right direction in FIG. 3(a)) of the first core 22, and the first active material layer 29 is formed on the first main surface 23 and the second main surface 24. The second double-sided coated portion 27 is provided continuously at the other end (right end in FIG. 3(a)) of the double-sided exposed portion 25 in the longitudinal direction of the first core 22, and the first active material layer 29 is formed on the first main surface 23 and the second main surface 24. The third double-sided coated section 28 is provided continuously with the double-sided exposed section 25 in the width direction of the first core 22 (the vertical direction in FIG. 3(a)), and a first active material layer 29 is formed on the first main surface 23 and the second main surface 24. The first double-sided coated section 26, the second double-sided coated section 27, and the third double-sided coated section 28 are connected in the longitudinal direction of the first core 22. The first core 22 is made of, for example, aluminum foil or aluminum alloy foil.

The double-sided exposed portion 25 of the first core 22 includes a first bonding region 25a to which the first lead 32 is bonded. The width dimension of the first lead 32 (left-right dimension in FIG. 3(a)) may be, for example, 2 mm or more and 4 mm or less. The width dimension of the first bonding region 25a (left-right dimension in FIG. 3(a)) may be, for example, 1 mm or more and 3 mm or less. In this embodiment, the first lead 32 is ultrasonically bonded to the first core 22 in the first bonding region 25a, but is not limited to this. The double-sided exposed portion 25 may be covered with an insulating tape (not shown) that is provided to cover the first lead 32.

The first identification display portion 31 that can identify the history of the manufacturing process of the first electrode plate 21 is formed on both the first main surface 23 and the second main surface 24 of the double-sided exposed portion 25 so that at least a portion of the first identification display portion 31 overlaps with the first joint region 25a in the thickness direction of the first core body 22 (the vertical direction in FIG. 3(b)). The first identification display portion 31 in this embodiment is a QR code (registered trademark) that is a two-dimensional code, but is not limited to this. Note that in FIG. 3(b), the first identification display portion 31 is shown as protruding from the first main surface 23 and the second main surface 24, but this is for convenience of explanation, and the first identification display portion 31 does not have to protrude from the first main surface 23 and the second main surface 24. For example, the first identification display portion 31 may be composed of a number of depressions (not shown) formed on the first main surface 23 and the second main surface 24 by laser irradiation. The depth of the recess may be, for example, 1 μm or more and 3 μm or less.

In the example shown in FIG. 3, the center of the first joint region 25a and the center of the first identification display portion 31 coincide with each other in the longitudinal direction of the first core body 22, but this is not limited to this. For example, the center of the first identification display portion 31 may be shifted to one side (e.g., the left side in FIG. 3(a)) from the center of the first joint region 25a in the longitudinal direction of the first core body 22. However, even if the centers of the two are shifted in this way, it is necessary that at least a portion of the first identification display portion 31 overlaps with the first joint region 25a in the thickness direction of the first core body 22.

Although not shown in the figures, the second electrode plate 33 comprises a strip-shaped second core body 34 having two main surfaces, and a second active material layer formed on the two main surfaces. The second core body 34 is made of, for example, copper foil or copper alloy foil. In this embodiment, the second active material layer is a negative electrode active material layer. In this embodiment, the length dimension of the second electrode plate 33 is greater than the length dimension of the first electrode plate 21, but is not limited to this.

The second core body 34 has a second joint region (not shown) to which the second lead 61 is joined. The second core body 34 has a second identification display portion 35 linked to the first identification display portion 31 formed so as not to overlap with the second joint region in the thickness direction. In other words, the second identification display portion 35 is an identification display portion that can identify the manufacturing history of the first electrode plate 21 and the second electrode plate 33. The second identification display portion 35 in this embodiment is a QR code (registered trademark), which is a two-dimensional code, but is not limited to this. The second identification display portion 35 in this embodiment is disposed on the outermost periphery of the electrode body 20, but is not limited to this. The second lead 61 is an example of a conductive member.

The outer can 40 contains the electrode body 20 and a non-aqueous electrolyte (not shown). The outer can 40 is made of metal and is formed into a bottomed cylinder with an opening at one end (the upper end in FIG. 1). A second lead 61, which is connected to the second electrode plate 33, is connected to the inner bottom surface of the outer can 40. Thus, the outer can 40 of this embodiment functions as an external negative electrode terminal. A ring-shaped second insulating plate 64 is provided between the inner bottom surface of the outer can 40 and the electrode body 20.

The sealing plate 50 seals the opening of the exterior can 40. A gasket 62 is arranged on the periphery of the sealing plate 50, and the inside of the exterior can 40 is sealed by crimping the open end of the exterior can 40 together with the gasket 62. The sealing plate 50 is electrically connected to the first electrode plate 21 via the first lead 32. Thus, the sealing plate 50 of this embodiment functions as an external positive electrode terminal. A ring-shaped first insulating plate 63 is provided between the sealing plate 50 and the electrode body 20.

Additional Notes
The above description of the embodiments discloses the following techniques.
(Technique 1)
A strip-shaped first core body having a first main surface and a second main surface;
an active material layer formed on the first principal surface and the second principal surface;
Equipped with
the first core body has a double-sided exposed portion on the first main surface and the second main surface where the active material layer is not formed,
the two-sided exposed portion includes a first bonding region to which a first lead is bonded;
An electrode plate, in which a first identification marking portion is formed on at least one of the first main surface and the second main surface of the both-side exposed portion so as to overlap at least a portion of the first bonding region in the thickness direction of the first core body.
(Technique 2)
The first core body is
a first double-sided coated section provided continuously to one end of the double-sided exposed section in the longitudinal direction of the first core body, the first double-sided coated section having the active material layer formed on the first main surface and the second main surface;
a second double-sided coated section provided continuously with the other end of the double-sided exposed section in the longitudinal direction of the first core body, the active material layer being formed on the first main surface and the second main surface;
The electrode plate according to claim 1, further comprising:
(Technique 3)
The electrode plate according to Technology 2, wherein the first core body further has a third double-sided coated portion that is provided continuously with the double-sided exposed portion in the width direction of the first core body and in which the active material layer is formed on the first main surface and the second main surface.
(Technique 4)
The electrode plate according to Technology 3, wherein the first double-sided coated portion, the second double-sided coated portion, and the third double-sided coated portion are connected in the longitudinal direction of the first core body.
(Technique 5)
The electrode plate according to any one of techniques 1 to 4, further comprising the first lead joined to the first joining region.
(Technique 6)
The battery includes a first electrode plate and a second electrode plate wound with a separator interposed therebetween,
The electrode body, wherein the first electrode plate is the electrode plate described in Technology 5.
(Technique 7)
The second electrode plate includes a strip-shaped second core body having a second bonding region to which a conductive member is bonded,
The electrode body according to Technology 6, wherein the second core body has a second identification marking portion formed so as not to overlap with the second bonding region in a thickness direction of the second core body.
(Technique 8)
The electrode body according to claim 7, wherein the second identification display portion is associated with the first identification display portion.
(Technique 9)
An electrode assembly according to any one of techniques 6 to 8,
a cylindrical exterior can containing the electrode assembly;
Equipped with a battery.

Although the present invention has been described with respect to the presently preferred embodiments, such disclosure is not to be interpreted as limiting. Various modifications and alterations will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. Accordingly, the appended claims should be construed to embrace all such modifications and alterations without departing from the true spirit and scope of the invention.

This disclosure can be used for electrode plates, electrode bodies, and batteries.

10: Battery 20: Electrode body 21: First electrode plate (electrode plate)
22: First core body 23: First main surface 24: Second main surface 25: Both-side exposed portion 25a: First bonding region 26: First both-side coated portion 27: Second both-side coated portion 28: Third both-side Coating part 29: first active material layer (active material layer)
31: First identification mark 32: First lead 33: Second electrode plate 34: Second core 35: Second identification mark 36: Separator 37: Tape 40: Outer can 50: Sealing plate 61: Second lead (Conductive member)
62: Gasket 63: First insulating plate 64: Second insulating plate

Claims (9)

A strip-shaped first core body having a first main surface and a second main surface;
an active material layer formed on the first principal surface and the second principal surface;
Equipped with
the first core body has a double-sided exposed portion on the first main surface and the second main surface where the active material layer is not formed,
the two-sided exposed portion includes a first bonding region to which a first lead is bonded;
An electrode plate, in which a first identification marking portion is formed on at least one of the first main surface and the second main surface of the both-side exposed portion so as to overlap at least a portion of the first bonding region in the thickness direction of the first core body. The first core body is
a first double-sided coated section provided continuously to one end of the double-sided exposed section in the longitudinal direction of the first core body, the first double-sided coated section having the active material layer formed on the first main surface and the second main surface;
a second double-sided coated section provided continuously with the other end of the double-sided exposed section in the longitudinal direction of the first core body, the active material layer being formed on the first main surface and the second main surface;
The electrode plate of claim 1 further comprising: The electrode plate according to claim 2, wherein the first core body further has a third double-sided coated portion that is continuous with the double-sided exposed portion in the width direction of the first core body and in which the active material layer is formed on the first main surface and the second main surface. The electrode plate of claim 3, wherein the first double-sided coated portion, the second double-sided coated portion, and the third double-sided coated portion are connected in the longitudinal direction of the first core body. An electrode plate according to any one of claims 1 to 4, further comprising the first lead joined to the first joining region. The battery includes a first electrode plate and a second electrode plate wound with a separator interposed therebetween,
An electrode assembly, wherein the first plate is the electrode plate according to claim 5 . The second electrode plate includes a strip-shaped second core body having a second bonding region to which a conductive member is bonded,
The electrode body according to claim 6 , wherein the second core body has a second identification marking portion formed thereon so as not to overlap the second bonding region in a thickness direction of the second core body. The electrode body according to claim 7, wherein the second identification display unit is associated with the first identification display unit. The electrode assembly according to claim 6 ,
a cylindrical exterior can containing the electrode assembly;
Equipped with a battery.

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