Battery manufacturing method

Abstract

The invention relates to a manufacturing method of a battery. A method of the present disclosure for manufacturing a battery includes roller-conveying a heated elongated sheet-like bipolar electrode laminate with a conveying roller. In the method of the present disclosure, the first electrode active material layer is configured from a plurality of island-shaped portions extending in the transport direction, at least one gap extending in the transport direction is present between the plurality of island-shaped portions, the temperature reduction of the bipolar electrode laminate when the bipolar electrode laminate passes through the transport roller is 30 DEG C or more, and the temperature reduction of the bipolar electrode laminate when the bipolar electrode laminate passes through the transport roller is 30 DEG C or more. The conveyance roller has a recessed portion at a position overlapping the gap portion or the opposite side surface thereof, so that at least a portion of the gap portion or the opposite side surface of the bipolar electrode laminate does not come into contact with the conveyance roller.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for manufacturing a battery. BACKGROUND

[0002] As disclosed in Japanese Patent Application Publication No. 2017-228349 and Japanese Patent Application Publication No. 2009-298496, a technique for suppressing generation of wrinkles in an electrode laminate subjected to roll conveying is known.

[0003] Japanese Patent Application Publication No. 2023-073069, Japanese Patent Application Publication No. 2022-066723, Japanese Patent Application Publication No. 2009-049006, and Japanese Patent Application Publication No. 2022-139880 disclose an electrode laminate having a gap portion formed in a plane of an electrode active material layer. SUMMARY

[0004] The present disclosers have found that, in manufacturing a bipolar electrode laminate having a gap portion formed in a plane of an electrode active material layer on one side, a crack is likely to occur in the electrode active material layer on the other side at a side opposite to the gap portion when subjected to roll conveying.

[0005] An object of the present disclosure is to provide a method for manufacturing a battery capable of suppressing a crack in an electrode active material layer.

[0006] The present disclosers and others have found that the above problem can be solved by the following means.

[0007] A method for manufacturing a battery,

[0008] comprises roll-conveying a long sheet-shaped bipolar electrode laminate heated by a pair of conveying rolls,

[0009] the bipolar electrode laminate has, in order, a first electrode active material layer, a current collector layer, and a second electrode active material layer,

[0010] the first electrode active material layer is composed of a plurality of island-shaped portions extending in a conveying direction, and at least one gap portion extending in the conveying direction is present between the plurality of island-shaped portions,

[0011] the bipolar electrode laminate is cooled by 30°C or more when passing through the conveying rolls, and the conveying rolls have a recess at a position overlapping with the gap portion or a side opposite thereto, thereby causing at least a part of the gap portion or the side opposite thereto of the bipolar electrode laminate to not contact the conveying rolls.

[0012] In the above-described method,

[0013] The width of the recess can also be the width of the gap portion or more.

[0014] In the above-described method,

[0015] In the above-described method,

[0016] In the above-described method,

[0017] The method can further include drying the first electrode active material layer and the second electrode active material layer by laser heating before the roll transport is performed.

[0018] In the above-described method,

[0019] The method can further include pressurizing the bipolar electrode laminate before the drying is performed.

[0020] According to the method of manufacturing a battery of the present disclosure, it is possible to suppress the occurrence of the above-described cracking of the electrode active material layer. BRIEF DESCRIPTION OF DRAWINGS

[0021] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, in which like reference numerals denote like elements, and wherein:

[0022] Figure 1 is a schematic view showing an example of the method of the present disclosure.

[0023] Figure 2 is a schematic cross-sectional view showing an example of the bipolar electrode laminate of the method of the present disclosure.

[0024] Figure 3 is a schematic plan view showing an example of the method of the present disclosure.

[0025] Figure 4 is a schematic cross-sectional view showing an example of the method of the present disclosure. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present disclosure will be described in detail. Furthermore, the present disclosure is not limited to the following embodiments, and can be implemented in various modifications within the scope of the gist of the present disclosure.

[0027] Method of manufacturing a battery

[0028] The method of manufacturing a battery of the present disclosure includes roll conveying a heated long strip-shaped bipolar electrode laminate with a conveying roller. In the method of the present disclosure, the bipolar electrode laminate successively has a first electrode active material layer, a current collector layer, and a second electrode active material layer, the first electrode active material layer is composed of a plurality of island-shaped portions extending in a conveying direction, and there is at least one gap portion extending in the conveying direction between the plurality of island-shaped portions, the temperature of the bipolar electrode laminate when passing through the conveying roller is 30°C or higher, and the conveying roller has a recess at a position overlapping with the gap portion or the opposite side surface thereof. Thereby, at least a part of the gap portion or the opposite side surface of the bipolar electrode laminate does not come into contact with the conveying roller.

[0029] As described above, the present disclosers have found that, in the manufacturing of a bipolar electrode laminate having a gap portion formed in the face of an electrode active material layer (first electrode active material layer) on one side, a breakage of an electrode active material layer (second electrode active material layer) on the other side is likely to occur in the opposite side surface of the gap portion when roll conveying is performed.

[0030] The present disclosers and others have considered that one of the reasons for the breakage of the second electrode active material layer in the opposite side surface of the gap portion is caused by thermal contraction. That is, it is considered that, when roll conveying a heated long strip-shaped bipolar electrode laminate with a conveying roller, the temperature of the bipolar electrode laminate decreases due to the conveying roller. The gap portion in the bipolar electrode laminate is less rigid than other portions, and thus it is considered that a wrinkle caused by thermal contraction is generated in the gap portion. It is considered that the breakage of the second electrode active material layer in the opposite side surface of the gap portion occurs due to interference of the thus generated wrinkle with the conveying roller.

[0031] In this regard, the present disclosers and others have found that, even if the temperature of the bipolar electrode laminate decreases due to the conveying roller, by providing a recess in the conveying roller at a position overlapping with the gap portion or the opposite side surface thereof, at least a part of the gap portion or the opposite side surface of the bipolar electrode laminate does not come into contact with the conveying roller, and thus the breakage of the second electrode active material layer in the opposite side surface of the gap portion can be suppressed. As a reason for this, it is considered that, by providing a recess in the conveying roller at a position overlapping with the gap portion or the opposite side surface thereof, even if a wrinkle is generated in the gap portion due to thermal contraction accompanying the temperature decrease of the bipolar electrode laminate, the generated wrinkle is less likely to interfere with the conveying roller.

[0032] Next, the method of manufacturing an electrode of the present disclosure will be described with reference to the drawings. Note that the dimensional relationships in the drawings do not reflect actual dimensional relationships.

[0033] Roll Conveying

[0034] As Figure 1As exemplified, the method of the present disclosure includes roll-transporting the heated long sheet-shaped bipolar electrode laminate 100 with the transport roller 20. Further, Figure 1 is a schematic diagram exemplifying a scheme in which the bipolar electrode laminate is wound to the winding spool 42 from the unwinding spool 41 via heating (drying) by the laser irradiation device 10 and roll-transporting by the transport roller 20.

[0035] The heating temperature is not particularly limited, and can be, for example, 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, 170°C or higher, 180°C or higher, 190°C or higher, or 200°C or higher, and can be 300°C or lower, 290°C or lower, 280°C or lower, 270°C or lower, 260°C or lower, or 250°C or lower. If the heating temperature is within the above range, it is considered that the temperature of the bipolar electrode laminate 100 easily decreases due to the transport roller 20 at the time of roll-transporting the bipolar electrode laminate 100 with the transport roller 20. If based on such a presumption, the method of the present disclosure is particularly effective for the bipolar electrode laminate heated at a temperature within the above range.

[0036] As exemplified in Figure 2 , in the method of the present disclosure, the bipolar electrode laminate successively has the first electrode active material layer 110, the current collector layer 130, and the second electrode active material layer 120.

[0037] As exemplified in Figure 2 and Figure 3 , in the method of the present disclosure, the first electrode active material layer 110 is composed of a plurality of island-shaped portions 111 extending in the transport direction, and at least one gap portion 131 extending in the transport direction is present between the plurality of island-shaped portions. Further, the transport direction is indicated with the arrow of Figure 3 .

[0038] The number of the island-shaped portions 111 and the gap portion 131 is not particularly limited. For example, in a case where the number of the gap portion 131 is set to n, the number of the island-shaped portions can be n+1. In this case, n is not particularly limited, and can be 1 or higher, 2 or higher, 3 or higher, 5 or higher, 7 or higher, 9 or higher, or 10 or higher, and can be 30 or lower, 25 or lower, 20 or lower, or 15 or lower.

[0039] The gap portion 131 can extend throughout the bipolar electrode laminate 100 in the transport direction of the bipolar electrode laminate 100, or can extend in a part of the bipolar electrode laminate 100.

[0040] The first electrode active material layer 110 composed of the plurality of island-shaped portions 111 can be either a positive electrode active material layer or a negative electrode active material layer, and particularly, can be a positive electrode active material layer. The second electrode active material layer 120 can be either a positive electrode active material layer or a negative electrode active material layer, and particularly, can be a negative electrode active material layer.

[0041] In the method of the present disclosure, the temperature drop of the bipolar electrode laminate 100 when passing through the conveyance roller 20 is 30°C or more.

[0042] The temperature drop of the bipolar electrode laminate 100 can be due to the temperature of the conveyance roller 20 being lower than the temperature of the bipolar electrode laminate 100 which has been heated.

[0043] The temperature drop of the bipolar electrode laminate 100 can be 40°C or more, 50°C or more, 60°C or more, 70°C or more, 80°C or more, 90°C or more, or 100°C or more, and can be 150°C or less, 130°C or less, or 110°C or less. If the temperature drop of the bipolar electrode laminate 100 is within the above range, thermal shrinkage is likely to occur at the gap portion 131 of the bipolar electrode laminate 100, and therefore, it is significant to apply the method of the present disclosure.

[0044] The temperature of the bipolar electrode laminate can be monitored with a thermometer such as a temperature sensor. Particularly, the thermometer can be a non-contact radiation thermometer.

[0045] As illustrated in Figure 3 and Figure 4 In the method of the present disclosure, the conveyance roller 20 has a recess 21 at a position overlapping with the gap portion 131 or the opposite side surface thereof. Thereby, at least a part of the gap portion 131 or the opposite side surface thereof, particularly, the entire gap portion 131 or the opposite side surface thereof, of the bipolar electrode laminate 100 is not in contact with the conveyance roller 20. By making such a structure, it is possible to suppress the occurrence of breakage of the second electrode active material layer 120 at the opposite side surface of the gap portion 131. Furthermore, in the scheme illustrated in Figure 3 and Figure 4 In the scheme illustrated in Figure 3 , the bipolar electrode laminate 100 is omitted at a portion overlapping with the conveyance roller 20 for convenience of explanation.

[0046] The position of the recess 21 at the conveyance roller 20 is not particularly limited as long as it is a position overlapping with at least a part of the gap portion 131 or the opposite side surface thereof. For example, as illustrated in Figure 4As illustrated, the position of the center of the recess 21 can substantially coincide with the position of the center of the gap portion 131 in the cross direction of the gap portion 131.

[0047] As illustrated, in the method of the present disclosure, the width of the recess 21 can be equal to or greater than the width of the gap portion 131. By making such a structure, the wrinkles generated at the gap portion 131 are less likely to interfere with the second electrode active material layer. In the present disclosure, the "width" means the length in the cross direction of the gap portion 131. Figure 3

[0048] The width of the recess 21 can be appropriately designed in consideration of the degree of wrinkles that can be generated at the gap portion 131 and the like.

[0049] The width of the gap portion can be appropriately set in consideration of the desired battery capacity and the like.

[0050] The recess 21 can be formed on a part of the outer periphery of the conveyance roller 20, or can be formed over the entire outer periphery.

[0051] In the method of the present disclosure, in the conveyance roller, the shape of the end portion of the portion other than the recess that contacts the bipolar electrode laminate is not particularly limited, but particularly, the end portion can be chamfered. By chamfering the end portion, damage to the bipolar electrode laminate 100 can be suppressed. Particularly, the chamfering can be a round (R) chamfering. The radius of the R chamfering in this case can be 0.1 mm or more, 0.3 mm or more, or 0.5 mm or more, and can be 10.0 mm or less, 5.0 mm or less, 3.0 mm or less, 2.0 mm or less, or 1.0 mm or less.

[0052] Further, in Figure 3 the present disclosure, a case where the second electrode active material layer 120 is arranged on the inner side in the radial direction of the conveyance roller 20, that is, on the side that contacts the conveyance roller 20 is illustrated. However, in the method of the present disclosure, the first electrode active material layer 110 can also be arranged on the side that contacts the conveyance roller 20.

[0053] In the method of the present disclosure, the temperature of the bipolar electrode laminate when being subjected to the roller conveyance is not particularly limited, and can be 40°C or more, 50°C or more, 60°C or more, 70°C or more, 80°C or more, 90°C or more, or 100°C or more, and can be 150°C or less, 140°C or less, 130°C or less, 120°C or less, 110°C or less, or 100°C or less. If the temperature is within the above range, the bipolar electrode laminate is easily cooled, and thus, the method of the present disclosure is significant.

[0054] ​When the bipolar electrode laminate 100 is roll-transported by the transport roller 20, the transport direction of the bipolar electrode laminate 100 can also be subjected to a direction change of a prescribed angle or more. In this case, the length of the bipolar electrode laminate 100 in contact with the transport roller 20 can be made longer, and thus the effect of preventing the second electrode active material layer from being broken by the recess 21 is large. The prescribed angle is not particularly limited, and can be 45° or more, 60° or more, 70° or more, 80° or more, 85° or more, or 90° or more, and can be 180° or less, 150° or less, 130° or less, 120° or less, 110° or less, 100° or less, 95° or less, or 90° or less.

[0055] In the method of the present disclosure, the transport roller can be used in multiple stages in the transport direction of the electrode active material layer. The number of stages of the transport roller is not particularly limited and can be appropriately set from the viewpoint of suppressing breakage of the electrode active material layer and saving space, and the like.

[0056] Drying

[0057] The method of the present disclosure can further include drying the first electrode active material layer 110 and the second electrode active material layer 120 by laser heating before roll-transportation is performed. By laser heating, the bipolar electrode laminate can be efficiently heated. When laser heating is performed, air blowing can also be performed in combination. The air blowing can also be hot air.

[0058] As Figure 1 illustrated, laser heating can be performed by the laser irradiation device 10. Furthermore, laser heating and roll-transportation can be performed continuously as Figure 1 illustrated, or can be performed discontinuously.

[0059] In the case where the first electrode active material layer and the second electrode active material layer are dried by laser heating, the object of laser irradiation can be any of the first and second electrode active material layers. In the case where the first electrode active material layer is a positive electrode active material layer, in particular, the first electrode active material layer can be irradiated with laser light to be heated.

[0060] Pressurization

[0061] Although not illustrated, the method of the present disclosure can further include pressurizing the bipolar electrode laminate 100 before drying.

[0062] In the case where the second electrode active material layer 120 contains a binder, in the second electrode active material layer 120 that has been subjected to pressurization, the binder is solidified by pressure, and thus the flexibility is generally considered to decrease. If based on such a presumption, it is particularly effective to apply the method of the present disclosure to the bipolar electrode laminate 100 that has been subjected to pressurization.

[0063] The method of pressurization is not particularly limited, and a conventional method can be employed.

[0064] The pressure of pressurization is not particularly limited, and can be appropriately set so that the density of the electrode active material layer becomes a desired value.

[0065] Low-temperature drying

[0066] The method of the present disclosure can further include drying the first and second electrode active material layers at a temperature lower than that in drying by the above-described laser heating before pressurization. The drying temperature in this process can be 80°C or higher, 90°C or higher, or 100°C or higher, and can be 140°C or lower, 130°C or lower, or 120°C or lower.

[0067] Battery

[0068] The battery of the present disclosure is manufactured by the method of the present disclosure for manufacturing a battery. In the battery of the present disclosure, the breakage of the second electrode active material layer at the opposite side surfaces of the gap portion 131 of the bipolar electrode laminate 100 can be suppressed.

[0069] The battery of the present disclosure can also include the bipolar electrode laminate 100, and optionally have an electrolyte layer.

[0070] The battery of the present disclosure can also be a liquid battery or a solid battery. Furthermore, in the present disclosure, "solid battery" means a battery that uses at least a solid electrolyte as an electrolyte, and thus, the solid battery can also use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. In addition, the solid battery of the present disclosure can also be a full solid battery, that is, a battery that uses only a solid electrolyte as an electrolyte.

[0071] The battery of the present disclosure can be a primary battery or a secondary battery. In particular, it can be a lithium ion secondary battery.

[0072] Hereinafter, each element constituting the battery will be described.

[0073] Current collector layer

[0074] As the current collector layer, a publicly known structure can be employed as the current collector layer of the battery. The current collector layer can be, for example, a copper foil, a copper alloy foil, a nickel foil, an aluminum foil, an aluminum alloy foil, a stainless steel foil, a carbon sheet, or the like.

[0075] The current collector layer can have two kinds of current collector layers that are different from each other. In this case, each current collector layer can be adhered to each other via a conductive adhesive layer, or can be joined by pressurization or the like. For example, the current collector layer on one side of the negative electrode active material layer can be a copper foil, and the current collector layer on one side of the positive electrode active material layer can be an aluminum foil.

[0076] The thickness of the current collector layer is not particularly limited and can be 1 μm or more and 300 μm or less, 5 μm or more and 200 μm or less, or 10 μm or more and 100 μm or less. In the case where the current collector layer has two current collector layers that are bonded to each other via a conductive adhesive layer, the total thickness of the respective layers can be in the above range.

[0077] The size of the current collector layer is not particularly limited and can be appropriately set, for example, in consideration of the capacity of a desired battery or the like.

[0078] The shape of the current collector layer in the battery obtained by the method of the present disclosure is not particularly limited and can be, for example, a quadrangle such as a rectangle.

[0079] The first and second electrode active material layers

[0080] The first and second electrode active material layers can also contain an electrode active material, and optionally contain a binder, a conductive auxiliary agent, and other components.

[0081] The electrode active material layer can be formed from an electrode composite material paste.

[0082] Further, in the present disclosure, a "composite material" means a composition that can constitute an electrode active material layer or the like as it is or by further containing other components. In addition, in the present disclosure, an "electrode composite material paste" means a paste that contains, in addition to a "composite material", a dispersion medium, whereby coating and drying can be performed to form an electrode active material layer or the like.

[0083] The thickness of the electrode active material layer is not particularly limited. The thickness of the electrode active material layer can be 10 μm or more and 500 μm or less, 100 μm or more and 450 μm or less, or 200 μm or more and 400 μm or less.

[0084] The size of the electrode active material layer is not particularly limited and can be appropriately set, for example, in consideration of the capacity of a desired battery or the like.

[0085] The shape of the first and second electrode active material layers in the battery obtained by the method of the present disclosure is not particularly limited and can be, for example, a quadrangle such as a rectangle.

[0086] The electrode active material

[0087] The electrode active material is not particularly limited. In the present disclosure, for example, in the case where the first electrode active material layer is a positive electrode active material layer, the first electrode active material layer can contain a positive electrode active material. In addition, for example, in the case where the second electrode active material layer is a negative electrode active material layer, the second electrode active material layer can contain a negative electrode active material.

[0088] As the positive active material, there is no particular limitation as long as it is a material having a higher potential than the negative active material. In the case where the bipolar electrode laminate of the present disclosure is a bipolar electrode laminate for a lithium ion secondary battery, as the positive active material, for example, lithium cobaltate (LiCoO2), lithium nickelate (LiNiO2), lithium manganate (LiMn2O4), a solid solution oxide (Li2MnO3-LiMO2 (M = Co, Ni, etc.)), lithium nickel manganate (LiNi 1 / 2 Mn 1 / 2 O2), lithium nickel cobalt manganate (LiNi 1 / 3Mn 1 / 3 Co 1 / 3 O2), olivine-type lithium phosphorus oxide (LiFePO4), and the like; polyaniline, polypyrrole, and the like; Li2S, CuS, Li-Cu-S compounds, TiS2, FeS, MoS2, Li-Mo-S compounds, Li-Ti-S compounds, Li-V-S compounds, and the like; acetylene black impregnated with sulfur, porous carbon impregnated with sulfur, a mixture powder of sulfur and carbon, and the like using sulfur as the active material; and the like. These positive active materials can be used singly or in combination of two or more.

[0089] The content of the positive active material in the positive composite material of the electrode composite material is not particularly limited and can be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 95% by mass or more.

[0090] The shape of the positive active material can be, for example, particulate.

[0091] As the negative active material, there is no particular limitation as long as it is a material having a lower potential than the positive active material. In the case where the bipolar electrode laminate of the present disclosure is a bipolar electrode laminate for a lithium ion secondary battery, as the negative active material, for example, graphite (artificial graphite, natural graphite), resin carbon, carbon fiber, activated carbon, hard carbon, soft carbon, and the like; metal-based materials mainly including tin, tin alloy, silicon, silicon alloy, gallium, gallium alloy, indium, indium alloy, aluminum, aluminum alloy, and the like; polynaphthalene, polyacetylene, polypyrrole, and the like; metallic lithium; Li4Ti5O 12 and the like; Li-Si alloy, Li-Sn alloy, Li-Al alloy, Li-Ga alloy, Li-Mg alloy, Li-In alloy, and the like. These negative active materials can be used singly or in combination of two or more.

[0092] The content of the negative active material in the negative electrode composite as the electrode composite is not particularly limited and can be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 95% by mass or more.

[0093] The shape of the negative active material can be, for example, particulate.

[0094] Binder

[0095] The binder is not particularly limited and, in the case where the battery of the present disclosure is a lithium ion secondary battery, for example, polyvinylidene fluoride (PVdF), polytetrafluoroethylene, polyethylene, polypropylene, an aromatic polyamide resin, a polyamide, a polyimide, a polyamide-imide, polyvinyl alcohol, polyacrylonitrile, polyacrylic acid, polymethyl acrylate, polyethyl acrylate, polyhexyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polyhexyl methacrylate, polyvinyl acetate, polyvinyl pyrrolidone, a polyether, a polyether sulfone, polyhexafluoropropylene, styrene butadiene rubber, carboxymethyl cellulose, and the like can be exemplified. These binders can be used alone or in combination with two or more kinds.

[0096] The content of the binder in the electrode composite is not particularly limited and can be appropriately set depending on the desired adhesiveness and the like.

[0097] Conductive auxiliary agent

[0098] The conductive auxiliary agent is not particularly limited and, in the case where the battery of the present disclosure is a lithium ion secondary battery, for example, graphite such as natural graphite and artificial graphite; carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, and pyrolytic carbon black; carbon fibers such as carbon nanotubes and conductive metal fibers; metal powders such as aluminum powder; conductive whiskers such as zinc oxide whiskers and conductive potassium titanate whiskers; conductive metal oxides such as titanium oxide; organic conductive materials such as phenylene derivatives; and the like can be exemplified. These conductive auxiliary agents can be used alone or in combination with two or more kinds.

[0099] The content of the conductive auxiliary agent in the electrode composite is not particularly limited and can be appropriately set depending on the desired conductivity and the like.

[0100] Other components

[0101] The electrode composite can also contain components other than those described above. As such components, a solid electrolyte, a dispersant, and the like are exemplified.

[0102] Examples 1 and 2 and Comparative Example 1

[0103] Example 1

[0104] The long strip-shaped bipolar electrode laminate was heated by laser irradiation. The positive electrode active material layer as the first electrode active material layer of the bipolar electrode laminate used was composed of a plurality of island-shaped portions extending in the conveyance direction as shown in Figure 2 and a plurality of gap portions extending in the conveyance direction were present between the plurality of island-shaped portions. In addition, the negative electrode active material layer as the second electrode active material layer of the bipolar electrode laminate used was present on the entire surface on the side opposite to the positive electrode active material layer as shown in Figure 2

[0105] As shown in Figure 3 and Figure 4 The heated bipolar electrode laminate was roll-conveyed using a conveyance roll having a recess at a position overlapping the side surface opposite to the gap portion. The roll-conveyance was performed with the negative electrode active material layer as the second electrode active material layer disposed on one side of the conveyance roll. The temperature drop of the bipolar electrode laminate upon passing through the conveyance roll was 30°C.

[0106] Example 2

[0107] The bipolar electrode laminate was roll-conveyed in the same manner as in Example 1 except that a conveyance roll whose end portion contacting the bipolar electrode laminate other than the recess was subjected to R chamfering processing (chamfering radius: 0.5 mm).

[0108] Comparative Example 1

[0109] The bipolar electrode laminate was roll-conveyed in the same manner as in Example 1 except that a conveyance roll having no recess was used.

[0110] Evaluation

[0111] Whether or not the negative electrode active material layer as the second electrode active material layer on the side surface opposite to the gap portion of the bipolar electrode laminate was cracked or damaged was visually confirmed. The results are shown in Table 1.

[0112] (Table 1)

[0113] ​

Claims

1. A method for manufacturing a battery, This includes using conveyor rollers to transport the heated, elongated, sheet-like bipolar electrode laminate. The bipolar electrode stack comprises, in sequence, a first electrode active material layer, a current collector layer, and a second electrode active material layer. The first electrode active material layer is composed of a plurality of island-shaped portions extending in the transport direction, and at least one gap extending in the transport direction exists between the plurality of island-shaped portions. The temperature drop of the bipolar electrode stack as it passes through the conveyor roller is above 30°C, and... The conveying roller has a recess at a position overlapping the gap or its opposite side, thereby preventing at least a portion of the gap or its opposite side of the bipolar electrode stack from contacting the conveying roller.

2. The method for manufacturing a battery according to claim 1, wherein, The width of the recess is greater than or equal to the width of the gap.

3. The method according to claim 1, wherein, In the conveying roller, the ends of the portion outside the recess that contact the bipolar electrode stack are chamfered.

4. The method for manufacturing a battery according to claim 1, wherein, It also includes drying the first electrode active material layer and the second electrode active material layer by laser heating before the roller conveying is performed.

5. The method for manufacturing a battery according to claim 4, wherein, It also includes pressurizing the bipolar electrode stack before the drying process.

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