Electrode plate and method for manufacturing the electrode plate
Patent Information
- Application Number
- KR1020260010682
- Authority / Receiving Office
- KR · KR
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-07
- Filing Date
- 2026-01-20
- Publication Date
- 2026-08-14
Smart Images
Figure P1020260010682_ABST
Abstract
Description
Technology Field
[0001] The present invention relates to an electrode plate and a method for manufacturing the electrode plate. Background Technology
[0002] For example, as an electrode plate of a capacitor device, it is known that a portion of the electrode foil is exposed, while an active material layer forming a dry film is pressed onto the electrode foil through a conductive adhesive layer provided on the other portion of the electrode foil (see Patent Document 1). Prior art literature
[0003] Japanese Patent Publication No. 2023-103999 The problem to be solved
[0004] However, among the electrode plates described above, there are cases where an insulating protective layer made of insulating ceramic powder or the like is provided between the exposed portion of the electrode foil and the adhesive layer, and then the active material layer is pressed against the electrode foil through the adhesive layer. This is because the exposed portion of the electrode foil may be bent for purposes such as current collection. However, due to this bending, the portion of the exposed portion of the electrode foil adjacent to the active material layer strongly contacts the corner portion of the end edge of the opposing electrode facing this portion through the separator. This is to prevent the problem of a large short-circuit current flowing when the end edge of the opposing electrode penetrates the separator and contacts the portion of the exposed portion of the electrode foil adjacent to the active material layer. Furthermore, even when a burr on the opposing electrode foil generated at the end edge of the opposing electrode penetrates the separator and contacts the portion of the exposed portion of the electrode foil adjacent to the active material layer, the insulating protective layer can prevent the problem of a large short-circuit current flowing.
[0005] However, in an electrode plate with an insulating protective layer formed in this manner, there are cases where the active material layer attached to the adhesive layer protrudes from the adhesive layer onto the insulating protective layer. In this case, if the insulating protective layer is formed to be thicker than the adhesive layer, when the active material layer is heat-pressed onto the adhesive layer, pressure is concentrated at the overlapping portion of the relatively thick insulating protective layer and the protruding active material layer near the boundary between the insulating protective layer and the adhesive layer. On the other hand, pressure is not sufficiently applied to the overlapping portion of the relatively thin adhesive layer and the active material layer, resulting in insufficient electrical conductivity between the active material layer and the electrode foil through the conductive adhesive layer in this area. Thus, there is a risk of non-uniformity in the battery reaction occurring in the active material layer attached to the adhesive layer.
[0006] The present invention has been made in consideration of these problems and aims to provide an electrode plate having an adhesive layer and an insulating protective layer on an electrode foil, wherein the active material layer is well adhered to the entire adhesive layer even if the active material layer protrudes to the insulating protective layer. Furthermore, the invention aims to provide a method for manufacturing such an electrode plate. means of solving the problem
[0007] (1) One embodiment of the present invention for solving the above problem comprises an electrode foil, a conductive adhesive layer provided on the electrode foil, an active material layer provided on the adhesive layer and adhered to the adhesive layer, and an insulating protective layer provided between the electrode foil exposure portion where the electrode foil is exposed and the adhesive layer along the adhesive layer and the active material layer, wherein the insulating protective layer is thinner than the adhesive layer.
[0008] The aforementioned electrode plate comprises, in addition to an adhesive layer and an active material layer adhered to the adhesive layer, an insulating protective layer formed along the adhesive layer and the active material layer on the electrode foil. Therefore, when an electrode body is formed using this electrode plate, the aforementioned insulating protective layer can suppress the occurrence of a short circuit caused by burrs on the opposing electrode foil, such as those formed at the corner or end edge portions of the opposing electrode's end edge portions, penetrating the separator and contacting the electrode foil of the electrode plate. Furthermore, the insulating protective layer is made thinner than the adhesive layer. Consequently, even if the active material layer adhered to the adhesive layer protrudes onto the insulating protective layer, the sum of the thicknesses of the insulating protective layer and the active material layer is smaller than the sum of the thicknesses of the adhesive layer and the active material layer. Therefore, appropriate pressure can be applied to the active material layer located on the adhesive layer, so the entire active material layer located on the adhesive layer adheres to the adhesive layer, making it difficult for non-uniformity in the battery reaction to occur.
[0009] Examples of electrode foils include metal foils such as aluminum foil or copper foil. Examples of active material particles in the active material layer include lithium transition metal composite oxide particles, such as lithium nickel cobalt manganese composite oxide particles; carbon-based particles such as graphite, carbon black (such as acetylene black); digraphitic carbon, nongraphitic carbon, and carbon nanotubes; and silicon-based particles. Examples of conductive particles included in the adhesive layer include acetylene black. Additionally, examples of thermoplastic resins for the adhesive layer include polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE). Examples of insulating ceramic powders for the insulating protective layer include alumina, magnesia, or silica. Additionally, examples of thermoplastic resins for the insulating protective layer include polyvinylidene fluoride or polytetrafluoroethylene.
[0010] As electrode plates, in addition to positive and negative plates in which non-metallic active material layers are formed on both sides of an electrode foil, electrode plates for bipolar secondary batteries in which a positive active material layer is formed on one side of an electrode foil and a negative active material layer is formed on the other side can also be cited. Furthermore, as storage devices using such electrode plates, secondary batteries that use ions of alkali metals such as Li, Na, and K as charge carriers, such as lithium-ion secondary batteries, can be cited. Additionally, capacitors such as lithium-ion capacitors can also be cited.
[0011] (2) The electrode plate described in (1) may be an electrode plate in which the active material layer is made of a self-supporting active material sheet.
[0012] (3) A method for manufacturing an electrode plate as described in any one of (1) to (2), wherein the method comprises a heat pressing process to form a strip electrode plate in which the strip active material layer is bonded to the strip adhesive layer, wherein the strip electrode plate has a strip adhesive layer formed on the strip electrode foil, a strip adhesive layer formed on both outer sides in the width direction of the strip adhesive layer, and a pair of strip insulating protective layers formed on the strip adhesive layer that are thinner than the strip adhesive layer, wherein the strip active material layer is overlapped on the strip adhesive layer and pressed while heating.
[0013] (4) A method for manufacturing an electrode plate as described in (3), wherein prior to the heat pressing process, an adhesive layer paste is applied in a strip shape on the strip electrode foil, leaving the strip-shaped exposed portion, and an undried strip-shaped adhesive layer is formed by drying, and a protective layer paste is applied in a strip shape to form an undried strip-shaped protective layer that becomes the strip-shaped adhesive layer, and simultaneously or sequentially, an adhesive layer paste is applied in a strip shape to form an undried strip-shaped protective layer that becomes the strip-shaped insulating protective layer by drying, and the adhesive layer is further provided in the application process of forming the undried strip-shaped adhesive layer and the undried strip-shaped protective layer so that the strip-shaped insulating protective layer becomes thinner than the strip-shaped adhesive layer, and the adhesive layer is further provided in the drying process of drying the undried strip-shaped adhesive layer and the undried strip-shaped protective layer to form the adhesive layer-equipped strip electrode foil having the strip-shaped adhesive layer and the strip-shaped insulating protective layer that is thinner than the strip-shaped adhesive layer.
[0014] (5) A method for manufacturing an electrode plate as described in (4), wherein the strip-shaped electrode foil having an adhesive layer has, on a first surface of the strip-shaped electrode foil, a first strip-shaped adhesive layer which is the strip-shaped adhesive layer and a first strip-shaped insulating protective layer which is the strip-shaped insulating protective layer, and on a second surface which is the back surface of the first surface of the strip-shaped electrode foil, a second strip-shaped adhesive layer which is the strip-shaped adhesive layer and a second strip-shaped insulating protective layer which is the strip-shaped insulating protective layer, and the heat pressing process involves, among the strip-shaped electrode foil having an adhesive layer, overlapping the first strip-shaped active material layer which is the strip-shaped active material layer with the first strip-shaped adhesive layer and overlapping the second strip-shaped active material layer which is the strip-shaped active material layer with the second strip-shaped adhesive layer, and simultaneously pressing the first strip-shaped active material layer while heating the first strip-shaped adhesive layer and simultaneously heating the second strip-shaped active material layer while The method of manufacturing an electrode plate can be a simultaneous heating and pressing process to form the strip-shaped electrode plate, wherein the first strip-shaped active material layer is adhered to the first strip-shaped adhesive layer and the second strip-shaped active material layer is adhered to the second strip-shaped adhesive layer. Brief explanation of the drawing
[0015] Figure 1 is a partial fracture cross-sectional view of a battery using a positive electrode plate in an electrode body according to an embodiment. FIG. 2 is an explanatory diagram illustrating the configuration of an electrode body including a positive electrode plate according to an embodiment. FIG. 3 is a cross-sectional view of a positive electrode plate according to an embodiment, indicated by the AA arrow in FIG. 2. Figure 4 is a flowchart of a method for manufacturing a positive electrode plate according to an embodiment. FIG. 5 is an explanatory diagram illustrating the overall configuration of a manufacturing apparatus used in a method for manufacturing a positive electrode plate according to an embodiment. FIG. 6 is a cross-sectional view of a strip-shaped positive electrode foil according to an embodiment, indicated by the BB arrow in FIG. 5. Specific details for implementing the invention
[0016] (Embodiment)
[0017] Hereinafter, a battery (1) (an example of a storage device) equipped with a positive electrode plate (5P) according to an embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. This battery (1) is a rectangular and sealed lithium-ion secondary battery and is installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric vehicles, or in various devices.
[0018] The battery (1) is composed of a battery case (2), an electrode body (5) housed inside the battery case (2), a positive electrode terminal (3) and a negative electrode terminal (4) fixedly installed in the battery case (2), and an insulating member (not shown) that insulates between them and the battery case (2). Among these, the battery case (2) is made of metal (aluminum in this embodiment) and is in the shape of a rectangular box. The electrode body (5) is covered with an insulating film in the shape of a pouch (not shown) inside the battery case (2). Additionally, an electrolyte (6) is housed inside the battery case (2), a portion of which is impregnated into the electrode body (5), and a portion of which is stored in the bottom of the battery case (2).
[0019] The positive electrode terminal (3) is made of an aluminum plate and has a long, slender shape. An internal connection part (3I) forming one end of the positive electrode terminal (3) is connected to a positive electrode current collection part (5PC) in which the positive electrode current collection foil (5PF) is exposed among the positive electrode plates (5P) (described later) constituting the electrode body (5). Meanwhile, the other end of the positive electrode terminal (3) is drawn out to the outside of the battery case (2) to form a positive electrode external terminal part (3G).
[0020] Additionally, the negative terminal (4) is made of a copper plate and has a long, slender shape. An internal connection part (4I) forming one end of the negative terminal (4) is connected to the negative current collection part (5NC) of the negative plate (5N) (described later) constituting the electrode body (5). Meanwhile, the other end of the negative terminal (4) is drawn out to the outside of the battery case (2) to form a negative external terminal part (4G).
[0021] The electrolyte (6) is a non-aqueous electrolyte having an organic solvent and a lithium salt containing fluorine. In this embodiment, an organic solvent mixed with ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate is used as the organic solvent. Additionally, LiPF6 is used as the lithium salt containing fluorine.
[0022] The electrode body (5) housed in the battery case (2) is a so-called flat wound electrode body, and is formed by winding a strip-shaped positive electrode plate (5P) and a strip-shaped negative electrode plate (5N) with a pair of strip-shaped separators (5S) interposed, and then pressing it in a direction perpendicular to the ground in FIG. 1 to make it flat.
[0023] Among the electrode bodies (5), the long strip-shaped negative electrode plate (5N) in the long side direction AH is provided with a strip-shaped negative electrode collecting foil (5NF) made of copper foil and a strip-shaped negative electrode active material layer (5NA) provided on both sides of the negative electrode collecting foil (5NF) (see FIG. 2). The negative electrode active material layer (5NA) is composed of negative electrode active material particles not shown and a binder. In this embodiment, graphite particles are used as the negative electrode active material particles. Additionally, the end edge portion of one side BH1 (downward in FIG. 2) in the width direction BH of the strip-shaped negative electrode plate (5N) is formed as a long strip-shaped negative electrode collecting portion (5NC) in the long side direction AH where the negative electrode active material layer (5NA) does not exist on the negative electrode collecting foil (5NF) and the negative electrode collecting foil (5NF) is exposed.
[0024] Meanwhile, the positive electrode plate (5P), which is a long strip in the direction of the long side AH, is provided with a strip in the direction of the positive electrode current collector (5PF) and a positive electrode active material layer (5PA) made of aluminum foil, in addition to a strip in the direction of the positive electrode current collector (5PX) and an adhesive layer (5PY) in the same manner (see FIG. 2 and FIG. 3). The end edge portion of the other side BH2 (upward in FIG. 2, leftward in FIG. 3) of the positive electrode plate (5P) in the direction of the width BH is formed as a strip in the direction of the long side AH of the positive electrode current collector (5PC) in which the positive electrode active material layer (5PA) is not present on the positive electrode current collector (5PF) and the positive electrode current collector (5PF) is exposed. In addition, the insulating protective layer (5PX) is provided along the adhesive layer (5PY) between the positive electrode current collector (5PC) and the adhesive layer (5PY). More specifically, in this embodiment, the insulating protective layer (5PX) is formed in contact with the adhesive layer (5PY).
[0025] Among these, the positive electrode active material layer (5PA) comprises positive electrode active material particles, conductive particles, and a binder made of fibrillated PTFE. This positive electrode active material layer (5PA) is composed of a so-called self-standing positive electrode active material sheet SH that exists and can be handled independently. This positive electrode active material sheet SH is a known "dry" active material sheet manufactured without using a solvent, and the layer thickness is, for example, 80 μm.
[0026] Additionally, as illustrated in FIG. 3, in the positive electrode plate (5P) of the present embodiment, the positive electrode active material layer (5PA) has a first portion PA1 that overlaps the adhesive layer (5PY) from the outer CHO of the thickness direction CH (upward and downward direction in FIG. 3). In addition, there may be a case where the positive electrode active material layer (5PA) does not overlap the adhesive layer (5PY) but protrudes onto the insulating protective layer (5PX) described later, and a second portion PA2 is formed that overlaps the insulating protective layer (5PX) from the outer CHO of the thickness direction CH. In this case, as illustrated in FIG. 3, the first portion PA1 of the positive electrode active material layer (5PA) is conductive to the positive electrode current collector foil (5PF) directly below through the conductive adhesive layer (5PY) containing conductive particles. In contrast, the second portion PA2, which overlaps with the insulating protective layer (5PX), cannot conduct electricity with the positive electrode current collector (5PF) immediately below it. Therefore, while the first portion PA1 can participate in the charge / discharge reaction in the battery (1), the second portion PA2 cannot participate in the charge / discharge reaction.
[0027] The adhesive layer (5PY) adheres the aforementioned positive electrode active material layer (5PA) to the positive electrode current collector foil (5PF). This adhesive layer (5PY) comprises conductive particles made of acetylene black and a thermoplastic resin made of PVDF. As shown in FIG. 3, this adhesive layer (5PY) is a layer formed so as to extend in the long side direction AH (direction perpendicular to the ground in FIG. 3), with one layer each on the first surface PFA and the second surface PFB of the positive electrode current collector foil (5PF). In this embodiment, the thickness of the layer CH in the thickness direction of this adhesive layer (5PY) is 6 μm.
[0028] The insulating protective layer (5PX) is a layer intended to suppress the flow of a large current caused by burrs generated on the corner portion of the negative electrode active material layer (5NA) or the negative electrode current collector foil (5NF) among adjacent negative electrode plates (5N) interposed by the separator (5S), penetrating the separator (5S), contacting the positive electrode current collector foil (5PF), and short-circuiting. This insulating protective layer (5PX) comprises insulating ceramic powder made of alumina and a thermoplastic resin made of PVDF. The thickness of the insulating protective layer (5PX) in the thickness direction CH of this embodiment is 3 μm, and is thinner than the thickness of the adhesive layer (5PY) described above. In addition, as described above, this insulating protective layer (5PX) overlaps with the second portion PA2 of the positive electrode active material layer (5PA) in the thickness direction CH.
[0029] For this reason, when the electrode body (5) is formed using the positive electrode plate (5P) of the present embodiment, the corner portion of the negative electrode current collection part (5NC) of the negative electrode plate (5N) or the burrs of the negative electrode current collection foil (5NF) can penetrate the separator (5S) and come into contact with the positive electrode current collection foil (5PF) of the positive electrode plate (5P), thereby preventing a short circuit from occurring. Furthermore, even if the positive electrode active material layer (5PA) adhered to the adhesive layer (5PY) protrudes onto the insulating protective layer (5PX), the sum of the thicknesses of the insulating protective layer (5PX) and the positive electrode active material layer (5PA) (second portion PA2) becomes smaller compared to the sum of the thicknesses of the adhesive layer (5PY) and the positive electrode active material layer (5PA) (first portion PA1). Therefore, the positive electrode active material layer (5PA) (first part PA1) overlapping the adhesive layer (5PY) can have pressure applied appropriately over the entire surface without being affected by the protruding part (second part PA2 of the positive electrode active material layer (5PA)). In this way, the entire first part PA1 of the positive electrode active material layer (5PA) adheres to the adhesive layer (5PY), making it difficult for non-uniformity of the battery reaction to occur in the first part PA1.
[0030] In addition, since this positive electrode plate (5P) uses a self-supporting positive electrode active material sheet SH in the positive electrode active material layer (5PA), it can be easily attached to the positive electrode current collector foil (5PF) through the adhesive layer (5PY), so the positive electrode plate (5P) can be formed at a low cost.
[0031] As illustrated in FIGS. 4 and 5, the method for manufacturing a positive electrode plate (5P) according to the present embodiment comprises a first adhesive paste layer application process S1, a first protective paste layer application process S2, and a first drying process S3. Additionally, it comprises a second adhesive paste layer application process S4, a second protective paste layer application process S5, and a second drying process S6. Furthermore, it comprises an active material sheet heating and pressing process S7 and a cutting process S8.
[0032] In the first adhesive paste layer application process S1, the first adhesive paste layer (5PY1) is formed by applying an adhesive paste PY in a strip shape to the central part of the width direction PFA1 on the first surface PFA of the strip-shaped positive electrode foil (5PF1), where the two end portions PFA2 of the width direction (direction perpendicular to the ground in FIG. 5, left-right direction in FIG. 6) of BH are emptied. Specifically, first, the strip-shaped positive electrode foil (5PF1) is unwound from the unwinder (81). Then, the adhesive paste PY is applied to the central part of the width direction PFA1 of the first surface PFA of the strip-shaped positive electrode foil (5PF1) being conveyed on the conveying roll (82) using the first die coater (101A) to a predetermined thickness (in this embodiment, the thickness after drying is 6 μm). In addition, the adhesive layer paste PY is a suspension of conductive particles in a solvent in addition to dissolving the aforementioned thermoplastic resin in a solvent.
[0033] In the subsequent first protective paste layer application process S2, a protective layer paste PX is applied to a portion of the two end portions of the width direction BH where the strip-shaped positive electrode foil (5PF1) is exposed and the first adhesive paste layer (5PY1) is not formed on the first surface PFA of the strip-shaped positive electrode foil (5PF1). Specifically, the protective layer paste PX is applied to the two outer sides (front side and depth side in FIG. 5, right side and left side in FIG. 6) of the width direction BH of the strip-shaped first adhesive paste layer (5PY1) formed on the first surface PFA of the strip-shaped positive electrode foil (5PF1) using a second die coater (102A) to a predetermined thickness (in this embodiment, the thickness after drying is 3㎛) to form the first protective paste layer (5PX1). In addition, the protective layer paste PX is a suspension of insulating ceramic particles in a solvent, in addition to dissolving the thermoplastic resin described above in a solvent.
[0034] In the first drying process S3, the formed first adhesive paste layer (5PY1) and the first protective paste layer (5PX1) are dried. Specifically, a drying booth (103) is used to volatilize (evaporate) the solvent in both paste layers (5PY1, 5PX1). As a result, the first strip adhesive layer (5PY2) and the first strip insulating protective layer (5PX2) are formed on the first surface PFA of the strip positive electrode foil (5PF1) after drying.
[0035] In the second adhesive paste layer application process S4, similar to the first adhesive paste layer application process S1, an adhesive layer paste PY is applied to the second surface PFB, which is the back surface of the first surface PFA of the strip-shaped positive electrode foil (5PF1), to form a second adhesive paste layer (5PY3) (in this embodiment, the thickness after drying is 6 μm). Specifically, the adhesive layer paste PY is applied in a strip shape to the central part PFB1 of the second surface PFB of the strip-shaped positive electrode foil (5PF1) in the width direction using a first die coater (101A).
[0036] In the second protective paste layer application process S5, just like in the first protective paste layer application process S2, a protective layer paste PX is applied to a part of the two end portions of the width direction BH of the second surface PFB of the strip-shaped positive electrode foil (5PF1) to form a second protective paste layer (5PX3) (in this embodiment, the thickness after drying is 3㎛).
[0037] In the second drying process S6, the formed second adhesive paste layer (5PY3) and second protective paste layer (5PX3) are dried using a drying booth (103), just like in the first drying process S3. As a result, a second strip adhesive layer (5PY4) and a second strip insulating protective layer (5PX4) are formed on the second surface PFB of the strip positive electrode foil (5PF1) after drying.
[0038] The adhesive layer-equipped strip-shaped positive electrode foil (5PF2) (see FIG. 6) at the end of the second drying process S6 has strip-shaped exposed portions (5PC1) in which strip-shaped positive electrode foils (5PF1) are exposed at both ends of the width direction BH of the first surface PFA. Additionally, a first strip-shaped adhesive layer (5PY2) is formed at the center of the width direction PFA1 of the first surface PFA, and a pair of first strip-shaped insulating protective layers (5PX2), which are thinner than the first strip-shaped adhesive layer (5PY2), are formed at both ends of the width direction BH of the first surface PFA PFA (both outer BH1, BH2) of the first strip-shaped adhesive layer (5PY2). Meanwhile, a second strip-shaped adhesive layer (5PY4) is formed in the central part of the width direction of the second surface PFB, PFB1, and a pair of second strip-shaped insulating protective layers (5PX4), which are thinner than the second strip-shaped adhesive layer (5PY4), are formed in the ends of the width direction of the second surface PFB, PFB2 (both outer BH1, BH2) of the second surface PFB.
[0039] According to each of the processes described above, a strip-shaped adhesive layer (5PY2, 5PY4) and a strip-shaped insulating protective layer (5PX2, 5PX4) thinner than this can be reliably formed on the strip-shaped positive electrode foil (5PF1).
[0040] In the continuing active material sheet heating and pressing process S7, among the adhesive layer-equipped strip-shaped positive electrode foil (5PF2) formed by processes S1 to S6, the first strip-shaped active material layer (5PA2) that has been separately formed is overlapped with the first strip-shaped adhesive layer (5PY2), and the second strip-shaped active material layer (5PA4) that has been separately formed is overlapped with the second strip-shaped adhesive layer (5PY4). After that, the strip-shaped active material layers (5PA2, 5PA4) are pressed while heating the strip-shaped adhesive layers (5PY2, 5PY4). Specifically, a known strip-shaped and self-supporting positive electrode active material sheet SH (e.g., layer thickness 80 μm), which is separately formed and wound on a reel (83), is unwound through a conveying roll (84) and overlapped to cover the first strip-shaped adhesive layer (5PY2) of the strip-shaped positive electrode foil (5PF2) equipped with an adhesive layer. In addition, the positive electrode active material sheet SH is unwound through the conveying roll (84) in the same manner and overlapped to cover the second strip-shaped adhesive layer (5PY4) of the strip-shaped positive electrode foil (5PF2) equipped with an adhesive layer. Then, using a roll press (104) consisting of two rolls (104A, 104B) heated to, for example, 80°C or higher, the positive electrode active material sheet SH is pressed against the first strip-shaped adhesive layer (5PY2) and the second strip-shaped adhesive layer (5PY4) while heating, respectively. Accordingly, a striped positive electrode plate (5P1) is formed having a first striped active material layer (5PA2) on the first surface PFA of the striped positive electrode foil (5PF1) and a second striped active material layer (5PA4) on the second surface PFB, respectively.
[0041] However, in the active material sheet heat pressing process S7, for example as shown in FIG. 3, a portion protruding from the strip adhesive layer (5PY2, 5PY4) among the strip active material layers (5PA2, 5PA4) (a portion corresponding to the second portion PA2) may be heat-pressed by a roll press (104) while positioned on the strip insulating protective layer (5PX2, 5PX4). However, in the strip positive electrode foil (5PF2) equipped with an adhesive layer of the present embodiment, the first strip insulating protective layer (5PX2) formed on the first surface PFA is thinner than the first strip adhesive layer (5PY2). Also, the second strip insulating protective layer (5PX4) formed on the second surface PFB is thinner than the second strip adhesive layer (5PY4). For this reason, pressure from the roll press (104) (roll (104A, 104B)) is applied to a first portion PA1 located on the strip adhesive layer (5PY2, 5PY4) among the strip active material layers (5PA2, 5PA4). In this way, the strip adhesive layer (5PY2, 5PY4) and the first portion PA1 located on the strip adhesive layer (5PY2, 5PY4) among the strip active material layers (5PA2, 5PA4) can be well adhered over the entire surface. In this way, the first portion PA1 of the positive electrode active material layer (5PA) is adhered to the adhesive layer (5PY), and a positive electrode plate (5P) that is conductive to the positive electrode current collector foil (5PF) can be manufactured.
[0042] In addition, the active material sheet heating and pressing process S7 uses a roll press (104) consisting of two rolls (104A, 104B) to heat and press the first strip-shaped active material layer (5PA2) against the first strip-shaped adhesive layer (5PY2), and at the same time heat and press the second strip-shaped active material layer (5PA4) against the second strip-shaped adhesive layer (5PY4). In this way, the first strip-shaped active material layer (5PA2) and the second strip-shaped active material layer (5PA4) can be attached to both sides of the first surface PFA and the second surface PFB of the strip-shaped positive electrode foil (5PF2) equipped with an adhesive layer, respectively, at once.
[0043] After that, in the cutting process S8, the strip-shaped positive electrode plate (5P1) is cut to obtain a positive electrode plate (5P). Specifically, first, the center of the strip-shaped positive electrode plate (5P1) in the width direction is cut in the long side direction using a first cutting cutter (106) to divide it in half. Then, a second cutting cutter (107) is used to cut it into a positive electrode plate (5P) of a predetermined long side dimension. In this way, the positive electrode plate (5P) is completed.
[0044] Although the present invention has been described above based on embodiments, the present invention is not limited to the embodiments described above and can be appropriately modified and applied within the scope without departing from the gist thereof.
[0045] For example, in the embodiment, the present invention is described as being applied to the positive electrode plate among the electrode plates. However, it may be applied to the negative electrode plate instead of the positive electrode plate, or applied to the negative electrode plate in addition to the positive electrode plate. Furthermore, in the embodiment, protective paste layer application processes S2 and S5 are illustrated, in which a protective layer paste PX is applied to each of the outer sides in the width direction of the adhesive paste layers (5PY1, 5PY3) formed on the strip-shaped positive electrode foil (5PF1) so as to be in contact with the adhesive paste layers (5PY1, 5PY3). That is, a positive electrode plate (5P) is illustrated in which the insulating protective layer (5PX) is provided in contact with the adhesive layer (5PY). However, the insulating protective layer may be provided between the exposed portion of the electrode foil and the adhesive layer along the adhesive layer and the active material layer. Accordingly, the insulating protective layer may be formed by applying the protective layer paste PX along the undried strip-shaped adhesive layer without contacting the undried strip-shaped adhesive layer formed on the strip-shaped electrode foil, leaving a gap.
[0046] In addition, in an embodiment, a positive electrode plate (5P) is exemplified having a positive electrode active material layer (5PA) having a second portion PA2 located on an insulating protective layer (5PX) in addition to having a first portion PA1 located on an adhesive layer (5PY) (see FIG. 3). However, it is not necessary for the second portion to always be present on the active material layer. In addition, in the active material sheet heat pressing process S7 (heat pressing process) of an embodiment, the process involves covering the first strip-shaped adhesive layer (5PY2) with the first strip-shaped active material layer (5PA2) (first strip-shaped active material layer) and covering the second strip-shaped adhesive layer (5PY4) with the second strip-shaped active material layer (5PA4) (second strip-shaped active material layer). However, for example, a process of covering the first strip-shaped adhesive layer with the first strip-shaped active material layer (5PA2) may be performed, and then a process of covering the second strip-shaped adhesive layer with the second strip-shaped active material layer (5PA4) may be performed. In addition, in an embodiment, the first adhesive paste layer (5PY1) was applied to the strip-shaped positive electrode foil (5PF1), and then the first protective paste layer (5PX1) was applied. That is, the first adhesive paste layer (5PY1) was applied before the first protective paste layer (5PX1). However, conversely, the first adhesive paste layer (5PY1) may be applied after the first protective paste layer (5PX1) has been applied. Alternatively, the first adhesive paste layer (5PY1) and the first protective paste layer (5PX1) may be applied simultaneously. Explanation of the symbols
[0047] 5P: Positive electrode plate (electrode plate) 5P1: Strip-type positive electrode plate (strip-type electrode plate) 5PA: Positive electrode active material layer (active material layer) 5PA2: First band-like active material layer (band-like active material layer) 5PA4: Second band-like active material layer (band-like active material layer) 5PC: Positive electrode current collector (electrode foil exposed part) 5PC1: Strip-shaped exposed part 5PF: Electrode collector (electrode foil) 5PF1: Strip-shaped positive electrode foil (strip-shaped electrode foil) 5PF2: Strip-shaped positive electrode foil with adhesive layer (Strip-shaped electrode foil with adhesive layer) 5PX: Insulation protection layer 5PX1: First protective paste layer (undried strip-shaped protective layer) 5PX2: First strip-shaped insulation protective layer (strip-shaped insulation protective layer) 5PX3: Second protective paste layer (undried strip-shaped protective layer) 5PX4: Second strip-shaped insulation protective layer (strip-shaped insulation protective layer) 5PY: Adhesive layer 5PY1: First adhesive paste layer (undried strip-shaped adhesive layer) 5PY2: 1st strip-shaped adhesive layer (strip-shaped adhesive layer) 5PY3: Second adhesive paste layer (undried strip-shaped adhesive layer) 5PY4: Second strip-shaped adhesive layer (strip-shaped adhesive layer) BH1: One side outer (in the width direction) BH2: The outer side (in the width direction) of the other side PFA: 1st side PFB: Page 2 PX: Protective layer paste PY: Adhesive layer paste S1: First adhesive paste layer application process (application process) S2: First protective paste layer application process (application process) S3: 1st drying process (drying process) S4: Second adhesive paste layer application process (application process) S5: Second protective paste layer application process (application process) S6: Second drying process (drying process) S7: Active material sheet heating and pressing process (heating and pressing process, simultaneous heating and pressing process) SH: Positive electrode active material sheet (active material sheet)
Claims
Claim 1 The electrode plate comprises an electrode foil, a conductive adhesive layer provided on the electrode foil, an active material layer provided on the adhesive layer and adhered to the adhesive layer, and an insulating protective layer provided between the electrode foil exposure portion where the electrode foil is exposed and the adhesive layer along the adhesive layer and the active material layer, wherein the insulating protective layer is thinner than the adhesive layer. Claim 2 In claim 1, the electrode plate, wherein the active material layer is composed of a self-supporting active material sheet. Claim 3 A method for manufacturing an electrode plate according to claim 1 or 2, comprising a heat pressing process to form a strip electrode plate in which the strip active material layer is adhered to the strip adhesive layer, wherein the strip electrode foil has a strip adhesive layer and a pair of strip insulating protective layers formed on both outer sides in the width direction of the strip adhesive layer, leaving a strip exposed portion on which the strip electrode foil is exposed in a strip shape, the strip electrode foil having a strip adhesive layer and a strip insulating protective layer thinner than the strip adhesive layer, wherein the strip active material layer is overlapped on the strip adhesive layer and pressed while heating. Claim 4 A method for manufacturing an electrode plate according to claim 3, comprising: a coating process in which, prior to the heat pressing process, an adhesive layer paste is applied in a strip shape on the strip-shaped electrode foil, leaving the strip-shaped exposed portion, to form an undried strip-shaped adhesive layer by drying, and simultaneously or sequentially, a protective layer paste is applied in a strip shape to form an undried strip-shaped protective layer by drying, thereby forming an undried strip-shaped protective layer along the undried strip-shaped adhesive layer; a coating process in which the undried strip-shaped adhesive layer and the undried strip-shaped protective layer are formed such that the strip-shaped insulating protective layer becomes thinner than the strip-shaped adhesive layer; and a drying process in which the undried strip-shaped adhesive layer and the undried strip-shaped protective layer are dried to form the adhesive layer-equipped strip-shaped electrode foil having the strip-shaped adhesive layer and the strip-shaped insulating protective layer that is thinner than the strip-shaped adhesive layer. Claim 5 In claim 4, the strip-shaped electrode foil equipped with an adhesive layer has, on a first surface of the strip-shaped electrode foil, a first strip-shaped adhesive layer which is the strip-shaped adhesive layer and a first strip-shaped insulating protective layer which is the strip-shaped insulating protective layer, and on a second surface which is the back surface of the first surface of the strip-shaped electrode foil, a second strip-shaped adhesive layer which is the strip-shaped adhesive layer and a second strip-shaped insulating protective layer which is the strip-shaped insulating protective layer, and the heat pressing process comprises, among the strip-shaped electrode foil equipped with an adhesive layer, overlapping the first strip-shaped active material layer which is the strip-shaped active material layer with the first strip-shaped adhesive layer and overlapping the second strip-shaped active material layer which is the strip-shaped active material layer with the second strip-shaped adhesive layer, and simultaneously pressing the first strip-shaped active material layer while heating the first strip-shaped adhesive layer and pressing the second strip-shaped active material layer while heating the second strip-shaped adhesive layer, thereby the first strip-shaped A method for manufacturing an electrode plate, comprising a simultaneous heating and pressing process for forming a strip-shaped electrode plate in which an active material layer is adhered to the first strip-shaped adhesive layer and a second strip-shaped active material layer is adhered to the second strip-shaped adhesive layer.