MANUFACTURING METHOD FOR ELECTRODE BODY, MANUFACTURING APPARATUS FOR ELECTRODE BODY, AND ELECTRODE BODY
20230395867 · 2023-12-07
Inventors
Cpc classification
H01M50/46
ELECTRICITY
H01M10/0583
ELECTRICITY
International classification
H01M10/0583
ELECTRICITY
H01M50/46
ELECTRICITY
Abstract
This disclosure achieves the object by providing a manufacturing method for an electrode body, the manufacturing method including: a preparing step of preparing an electrode sheet including one separator, a plurality of first electrodes placed on a first surface of the separator, and a plurality of second electrodes placed on a second surface opposite from the first surface of the separator; and a laminating step of laminating the first electrodes and the second electrodes in the electrode sheet alternately via the separator. The electrode sheet satisfies predetermined conditions (i) to (iii) in a plan view in the thickness direction of the electrode sheet. In the laminating step, the first electrodes and the second electrodes are laminated alternately via the separator while the separator placed on a side surface of each of the first electrodes is brought into contact with a wall portion inclined from the vertical direction.
Claims
1. A manufacturing method for an electrode body, the manufacturing method comprising: a preparing step of preparing an electrode sheet including one separator, a plurality of first electrodes placed on a first surface of the separator, and a plurality of second electrodes placed on a second surface opposite from the first surface of the separator; and a laminating step of laminating the first electrodes and the second electrodes in the electrode sheet alternately via the separator, wherein: the electrode sheet satisfies the following conditions (i) to (iii) in a plan view in a thickness direction of the electrode sheet (i) the first electrodes and the second electrodes are placed alternately in a first direction, (ii) the first electrodes and the second electrodes are placed not to overlap with each other, and (iii) the first electrodes have an area larger than an area of the second electrodes; and in the laminating step, the first electrodes and the second electrodes are laminated alternately via the separator while the separator placed on a side surface of each of the first electrodes is brought into contact with a wall portion inclined from a vertical direction.
2. The manufacturing method according to claim 1, wherein: the separator in the electrode body includes, in a sectional view of the electrode body in a lamination direction, unit structures each including a first facing portion, a second facing portion, and a first connecting portion, and a second connecting portion connecting adjacent unit structures to each other; the first facing portion faces a corresponding first electrode and has a length corresponding to a length of the corresponding first electrode in a width direction; the second facing portion faces a corresponding second electrode and has a length corresponding to a length of the corresponding second electrode in the width direction; the first connecting portion connects the first facing portion and the second facing portion to each other and covers a side surface of the corresponding first electrode; and the second connecting portion connects the first facing portion in a first unit structure out of the adjacent unit structures to the second facing portion in a second unit structure out of the adjacent unit structures.
3. The manufacturing method according to claim 2, wherein, in a plan view of the electrode sheet from the thickness direction, W.sub.γ satisfies W.sub.γ=T.sub.1+ε(W.sub.α−W.sub.β)/2 (0.9≤ε≤1.1), where W.sub.α indicates a length of the corresponding first electrode in the first direction, W.sub.β indicates a length of the corresponding second electrode in the first direction, W.sub.γ indicates a length of a first blank portion corresponding to the first connecting portion in the first direction, and T.sub.1 indicates a thickness of the first electrode.
4. The manufacturing method according to claim 1, wherein: the first electrodes each include a first current collection layer, and a first active material layer placed on each surface of the first current collection layer; and the second electrodes each includes a second current collection layer, and a second active material layer placed on each surface of the second current collection layer.
5. The manufacturing method according to claim 1, wherein the first electrodes are negative electrodes, and the second electrodes are positive electrodes.
6. A manufacturing apparatus for an electrode body, the manufacturing apparatus being used for the manufacturing method according to claim 1, the manufacturing apparatus comprising: a conveyance member configured to convey the electrode sheet; and a storage member in which the electrode sheet conveyed from the conveyance member is stored, the storage member including the wall portion.
7. An electrode body including first electrodes and second electrodes laminated alternately via one separator, wherein: the separator includes, in a sectional view of the electrode body in a lamination direction, unit structures each including a first facing portion, a second facing portion, and a first connecting portion, and a second connecting portion connecting adjacent unit structures to each other; the first facing portion faces a corresponding first electrode and has a length corresponding to a length of the corresponding first electrode in a width direction; the second facing portion faces a corresponding second electrode and has a length corresponding to a length of the corresponding second electrode in the width direction; the first connecting portion connects the first facing portion and the second facing portion to each other and covers a side surface of the corresponding first electrode; and the second connecting portion connects the first facing portion in a first unit structure out of the adjacent unit structures to the second facing portion in a second unit structure out of the adjacent unit structures.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein:
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DETAILED DESCRIPTION OF EMBODIMENTS
[0030] The following describes details of a manufacturing method for an electrode body, a manufacturing apparatus for an electrode body, and an electrode body according to this disclosure, with reference to the drawings. Each of the following drawings is illustrated schematically, and the magnitude and the shape of each part are exaggerated appropriately to facilitate understanding. Further, in the present specification, in a case where merely the term “above” or “below” is described to express an arrangement of a second member relative to a first member, this arrangement includes both a case where the second member is placed right above or right below the first member such that the second member makes contact with the first member, and a case where the second member is placed above or below the first member via a third member, unless otherwise specified.
[0031] A. Manufacturing Method for Electrode Body
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[0036] In this disclosure, the first electrodes and the second electrodes are laminated alternately via the separator by using a predetermined electrode sheet with the use of the wall portion inclined from the vertical direction, thereby making it possible to balance improvement in productivity with restraint of breakage of the electrodes. As described above, in a case where an electrode body is manufactured by the winding method, when a positional deviation between electrodes occurs at the time of winding, the positional deviation causes an influence cumulatively. Accordingly, when the winding speed is raised to improve productivity, for example, the electrodes (particularly, an edge portion) may break under the accumulated influences of the positional deviation. In contrast, in this disclosure, the first electrodes and the second electrodes are laminated alternately via the separator with the use of the wall portion inclined from the vertical direction. The positional relationship between the first electrode and the second electrode in the lamination direction is defined by the length of the separator (the length of a first blank portion (described later)) brought into contact with the wall portion, and therefore, there is such an advantage that the influence of a positional deviation between electrodes does not occur cumulatively. On that account, even when the speed of the electrode sheet is raised to improve productivity, for example, it is possible to restrain the electrodes from breaking.
[0037] 1. Preparing Step
[0038] A preparing step in this disclosure is a step of preparing a predetermined electrode sheet. As illustrated in
[0039] The electrode sheet in this disclosure satisfies the following conditions (i) to (iii) in a plan view in the thickness direction. The “thickness direction of the electrode sheet” indicates a normal direction of a principal surface (the first surface and the second surface) of the separator.
[0040] The condition (i) is as follows. That is, the first electrodes and the second electrodes are placed alternately in the first direction. The first direction is typically the longitudinal direction of the electrode sheet. The electrode sheet is conveyed in its longitudinal direction, in general. For example, in
[0041] The condition (ii) is as follows. That is, the first electrodes and the second electrodes are placed not to overlap with each other. More specifically, in the first direction, a blank portion in which the first electrode and the second electrode are not present is placed between the first electrode and the second electrode. For example, the electrode sheet 50 illustrated in
[0042] As illustrated in
[0043] The positional relationship between the first electrode and the second electrode in the lamination direction is defined by the length W.sub.γ of the first blank portion B.sub.1 brought into contact with the wall portion. W.sub.γ is not limited in particular, provided that W.sub.γ has a value that allows the first electrode and the second electrode to be laminated via the separator, but it is preferable to satisfy W.sub.γ=T.sub.1+ε(W.sub.α−W.sub.β)/2 (0.9≤ε≤1.1). By satisfying this relationship, it is possible to obtain an electrode body in which the center of the first electrode accords with the center of the second electrode in the lamination direction. For example, in
[0044] Further, W.sub.δ is not limited in particular, provided that W.sub.δ has a value that allows the first electrode and the second electrode to be laminated via the separator, but for example, it is preferable to satisfy W.sub.δ≥{(T.sub.2).sup.2+((W.sub.α−W.sub.β)/2).sup.2}.sup.1/2. As described above, since the positional relationship between the first electrode and the second electrode in the lamination direction is defined by the length W.sub.γ of the first blank portion B.sub.1 brought into contact with the wall portion, WO does not affect the positional relationship, basically.
[0045] The condition (iii) is as follows. That is, the area of the first electrode is larger than the area of the second electrode. For example, as illustrated in
[0046] When W.sub.α indicates the length (width) of the first electrode in the first direction, and W.sub.β indicates the length (width) of the second electrode in the first direction, it is preferable that W.sub.α be larger than W.sub.β. The ratio of W.sub.α to W.sub.β (W.sub.α/W.sub.β) is, for example, equal to or more than 1.01, may be equal to or more than 1.05, or may be equal to or more than 1.1. Meanwhile, W.sub.α/W.sub.β is, for example, equal to or less than 1.5.
[0047] When D.sub.α indicates the length (depth) of the first electrode in the second direction perpendicular to the first direction, and Do indicates the length (depth) of the second electrode in the second direction, it is preferable that D.sub.α be larger than D.sub.β. The ratio of D.sub.α to D.sub.β (D.sub.α/D.sub.β) is, for example, equal to or more than 1.01, may be equal to or more than 1.05, or may be equal to or more than 1.1. Meanwhile, D.sub.α/D.sub.β is, for example, equal to or less than 1.5.
[0048] The electrode sheet includes one separator, a plurality of first electrodes, and a plurality of second electrodes. The separator is a porous membrane, in general. Examples of the material for the separator include resins such as polyethylene (PE), polypropylene (PP), polyester, cellulose, and polyamide, for example. The separator may have a single-layered structure or may have a multi-layered structure. Examples of the separator having a multiple-layered structure include a separator having a two-layer structure of PE/PP, and a separator having a three-layer structure of PP/PE/PP or PE/PP/PE, for example. Further, the separator may be made of a woven fabric or may be made of a nonwoven fabric. The thickness of the separator is not limited in particular but is equal to or more than 0.1 μm but equal to or less than 1 mm, for example.
[0049] The first electrode includes, for example, a first current collection layer, and a first active material layer placed on each surface of the first current collection layer. Further, the first electrode is a positive electrode or a negative electrode. In a case where the first electrode is a positive electrode, the first electrode includes a positive-electrode current collection layer and a positive-electrode active material layer. In the meantime, in a case where the first electrode is a negative electrode, the first electrode includes a negative-electrode current collection layer and a negative-electrode active material layer. It is preferable that the first electrode be a negative electrode. This is because it is possible to restrain deposition of dendrite.
[0050] The second electrode includes, for example, a second current collection layer, and a second active material layer placed on each surface of the second current collection layer. Further, the second electrode is a positive electrode or a negative electrode. In a case where the first electrode is a positive electrode, the second electrode is a negative electrode and includes a negative-electrode current collection layer and a negative-electrode active material layer. In the meantime, in a case where the first electrode is a negative electrode, the second electrode is a positive electrode and includes a positive-electrode current collection layer and a positive-electrode active material layer. Materials used for the positive-electrode current collection layer, the positive-electrode active material layer, the negative-electrode current collection layer, and the negative-electrode active material layer are not limited in particular, and well-known materials are used.
[0051] 2. Laminating Step
[0052] The laminating step in this disclosure is a step of laminating the first electrodes and the second electrodes in the electrode sheet alternately via the separator. In the laminating step, while the separator (the first blank portion) placed on the side surface of the first electrode is brought into contact with the wall portion inclined from the vertical direction, the first electrodes and the second electrodes are laminated alternately via the separator.
[0053] As illustrated in
[0054] As illustrated in
[0055] As illustrated in
[0056] As illustrated in
[0057] As illustrated in
[0058] 3. Electrode Body
[0059] The electrode body in this disclosure is an electrode body in which the first electrodes and the second electrodes are laminated alternately via one separator. The separator in the electrode body includes, in a sectional view in the lamination direction of the electrode body, the unit structure including the first facing portion, the second facing portion, and the first connecting portion, and the second connecting portion connecting adjacent unit structures to each other. The “lamination direction of the electrode body” indicates a direction where the first electrode and the second electrode are laminated via the separator.
[0060] As illustrated in
[0061] This disclosure can provide a battery including the electrode body described above. The battery may include the electrode body, an electrolytic solution with which the electrode body is impregnated, and an outer packaging body in which the electrode body and the electrolytic solution are stored. The type of the electrolytic solution is not limited in particular, and a well-known electrolytic solution is used. Further, the type of the outer packaging body is not limited in particular, and a well-known outer packaging body is used. The type of the battery is not limited in particular, but the battery is a lithium-ion secondary battery, for example. The purpose of the battery is, for example, a power supply of a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), a gasoline-fueled automobile, or a diesel powered automobile. Particularly, it is preferable that the battery be used for a drive power supply of a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV). Further, the battery in this disclosure may be used as a power supply of a movable body (e.g., a train, a vessel, an aircraft) other than the vehicle or may be used as a power supply of an electric appliance such as an information processing device.
[0062] B. Manufacturing Apparatus for Electrode Body
[0063] A manufacturing apparatus for an electrode body in this disclosure is used for the aforementioned manufacturing method for the electrode body and includes a conveyance member configured to convey the electrode sheet, and a storage member in which the electrode sheet conveyed from the conveyance member is stored, the storage member having the aforementioned wall portion.
[0064] In this disclosure, the manufacturing apparatus includes the storage member having the wall portion inclined from the vertical direction, and therefore, it is possible to achieve a manufacturing apparatus for an electrode body, the manufacturing apparatus balancing improvement in productivity with restraint of breakage of an electrode.
[0065] The conveyance member in this disclosure includes, for example, a support portion configured to support the electrode sheet, and a driving portion configured to move the position of the support portion. For example, a conveyance member 60 illustrated in
[0066] The storage member in this disclosure has at least the wall portion inclined from the vertical direction. For example, a storage member 70 illustrated in
[0067] The manufacturing apparatus for the electrode body in this disclosure may include a guide member configured to assist the conveyance of the electrode sheet as needed. For example, the manufacturing apparatus of the electrode body, as illustrated in
[0068] C. Electrode Body
[0069] The electrode body in this disclosure is similar to what is described in “A. Manufacturing Method for Electrode Body,” and therefore, the electrode body in this disclosure is not described herein.
[0070] This disclosure is not limited to the above embodiment. The above embodiment is just an example and has a configuration substantially the same as the technical idea described in claims in this disclosure, and any configuration that can yield similar effects is included the technical scope of this disclosure.