Battery manufacturing device and method for manufacturing battery

Abstract

To improve the efficiency of manufacturing a battery.SOLUTION: A battery manufacturing device includes: a first manufacturing unit for executing a first step including continuously supplying an electrode composition including an active material to a release film to convey and continuously compressing the electrode composition supplied on the release film; and a second manufacturing unit for executing a second step including introducing the electrode composition separated from the release film and divided on a unit-by-unit basis into the assembly step.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present invention relates to a battery manufacturing apparatus and a battery manufacturing method. [Background technology]

[0002] Batteries such as lithium ion batteries are generally used in the form of a combination of a plurality of unit cells (also referred to as unit cells or battery cells). As described in Patent Document 1, for example, a unit cell is composed of an active material layer, a current collector layer, a separator, and a frame that encapsulates the active material layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6633866 [Patent Document 2] Patent No. 7220860 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to efficiently manufacture cells, it is possible to carry out the steps up to assembling the cells continuously as a series of lines, as described in Patent Document 2, for example. However, the time required for each step up to assembling the cells is not constant, and the speed of the entire series of lines may be limited by a time-consuming step. Also, for some steps, incorporating them into a series of lines may make it difficult to ensure accuracy.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a battery manufacturing apparatus and a battery manufacturing method that can improve the efficiency of battery manufacturing. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the battery manufacturing apparatus of the present invention comprises a first manufacturing unit that performs a first step including at least continuously supplying an electrode composition containing an active material to a release film being transported and continuously compressing the electrode composition supplied onto the release film, and a second manufacturing unit that performs a second step including at least introducing the electrode composition separated from the release film and divided into units into an assembly process. Effect of the Invention

[0007] According to the battery manufacturing apparatus and battery manufacturing method of the present invention, it is possible to improve the efficiency of battery manufacturing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of a single cell of a battery manufactured using a battery manufacturing apparatus according to an embodiment. [Figure 2A] FIG. 2A is a schematic diagram of a first manufacturing device included in the battery manufacturing apparatus of the embodiment. [Figure 2B] FIG. 2B is a schematic diagram of a second manufacturing device included in the battery manufacturing apparatus of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description may show characteristic parts in an enlarged scale for the purpose of emphasizing the characteristic parts, and the dimensional ratios of each component may not be the same as the actual ones. Also, for the same purpose, some parts may be omitted in the drawings.

[0010] <Battery pack (secondary battery)> The battery manufacturing apparatus and the battery manufacturing method of the embodiment are applied to, for example, the manufacture of lithium ion batteries. Lithium ion batteries are used in the form of a modularized battery assembly formed by combining a plurality of lithium ion single batteries (also referred to as single cells or battery cells), or in the form of a battery pack formed by combining a plurality of such battery assemblies and adjusting the voltage and capacity. An example of a lithium ion secondary battery is shown below, but the type of secondary battery according to the present invention is not limited to a lithium ion secondary battery and includes other secondary batteries.

[0011] <Single cell (battery cell)> 1 is a schematic cross-sectional view of a unit cell 10. The above-mentioned battery pack can be manufactured by combining a plurality of unit cells 10. For example, the unit cell 10 has a positive electrode 20a and a negative electrode 20b as two electrodes 20 (battery electrodes), and a separator 30.

[0012] The separator 30 is disposed between the positive electrode 20a and the negative electrode 20b. In the assembled battery, the multiple single cells 10 are stacked with the positive electrodes 20a and the negative electrodes 20b facing in the same direction.

[0013] The separator 30 holds an electrolyte. Thus, the separator 30 functions as an electrolyte layer. The separator 30 is disposed between the electrode active material layers 22 of the positive electrode 20a and the negative electrode 20b, and prevents them from contacting each other. Thus, the separator 30 functions as a partition wall between the positive electrode 20a and the negative electrode 20b.

[0014] Examples of the electrolyte held in the separator 30 include an electrolytic solution or a gel polymer electrolyte. By using these electrolytes, high lithium ion conductivity is ensured. Examples of the form of the separator include a porous sheet separator made of a polymer or fiber that absorbs and holds the electrolyte, a nonwoven fabric separator, and the like.

[0015] The positive electrode 20a and the negative electrode 20b each have a current collector layer 21, an electrode active material layer 22, and a frame 35. The electrode active material layer 22 and the current collector layer 21 are arranged in this order from the separator 30 side. The frame 35 is frame-shaped (annular). The frame 35 surrounds the periphery of the electrode active material layer 22. The frame 35 of the positive electrode 20a and the frame 35 of the negative electrode 20b are welded to each other and integrated. Alternatively, the frame 35 of the positive electrode 20a and the frame 35 of the negative electrode 20b may be integrally manufactured from the beginning. That is, the frame 35 of the positive electrode 20a and the frame 35 of the negative electrode 20b may be manufactured separately and then integrated, or may be manufactured as a single member. In the following description, when the electrode active material layers 22 of the positive electrode 20a and the negative electrode 20b are to be distinguished from each other, they will be referred to as a positive electrode active material layer 22a and a negative electrode active material layer 22b, respectively.

[0016] <Specific examples of positive electrode current collectors> As the positive electrode current collector constituting the positive electrode current collector layer 21a, a current collector used in a known lithium ion cell can be used, for example, a known metal current collector and a resin current collector composed of a conductive material and a resin (such as the resin current collectors described in JP 2012-150905 A and WO 2015 / 005116 A, etc.) can be used. From the viewpoint of battery characteristics, etc., the positive electrode current collector constituting the positive electrode current collector layer 21a is preferably a resin current collector.

[0017] Examples of the metal current collector include one or more metal materials selected from the group consisting of copper, aluminum, titanium, nickel, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, alloys containing one or more of these metals, and stainless steel alloys. These metal materials may be used in the form of a thin plate or metal foil. In addition, the above metal materials may be formed on the surface of a substrate made of a material other than the above metal materials by a method such as sputtering, electrodeposition, or coating, and used as the metal current collector.

[0018] The resin collector preferably contains a conductive filler and a matrix resin. Examples of the matrix resin include, but are not limited to, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), etc. The conductive filler is not particularly limited as long as it is selected from materials having electrical conductivity. The conductive filler may be a conductive fiber having a fibrous shape.

[0019] The resin current collector may contain other components (such as a dispersant, a crosslinking accelerator, a crosslinking agent, a colorant, an ultraviolet absorber, and a plasticizer) in addition to the matrix resin and the conductive filler. A plurality of resin current collectors may be laminated, or a resin current collector and a metal foil may be laminated.

[0020] The thickness of the positive electrode collector layer 21a is not particularly limited, but is preferably 5 to 150 μm. When a plurality of resin collectors are laminated to be used as the positive electrode collector layer 21a, the total thickness after lamination is preferably 5 to 150 μm. The positive electrode collector layer 21a can be obtained, for example, by melt-kneading a matrix resin, a conductive filler, and an optional filler dispersant to obtain a conductive resin composition, and molding the conductive resin composition into a film by a known method.

[0021] <Specific examples of positive electrode active materials> The positive electrode active material layer 22a is preferably a non-binding body of a mixture containing a positive electrode active material. Here, the non-binding body means that the position of the positive electrode active material in the positive electrode active material layer is not fixed, and the positive electrode active materials are not irreversibly fixed to each other and to the positive electrode active material and the current collector. When the positive electrode active material layer 22a is a non-binding body, the positive electrode active materials are not irreversibly fixed to each other, so that the interface between the positive electrode active materials can be separated without mechanically destroying it, and even if stress is applied to the positive electrode active material layer 22a, the positive electrode active material moves, so that destruction of the positive electrode active material layer 22a can be prevented, which is preferable. The positive electrode active material layer 22a that is a non-binding body can be obtained by, for example, making the positive electrode active material layer 22a into a positive electrode active material layer 22a that contains a positive electrode active material and an electrolyte but does not contain a binder. In this specification, the binder means a chemical that cannot reversibly fix the positive electrode active materials to each other and the positive electrode active material and the current collector. These binders are used by dissolving or dispersing them in a solvent, and when the solvent is evaporated or distilled off, the surface solidifies without exhibiting any adhesiveness, and therefore cannot reversibly fix the positive electrode active materials together or between the positive electrode active material and the current collector.

[0022] Examples of the positive electrode active material include, but are not limited to, composite oxides of lithium and transition metals, composite oxides containing two types of transition metal elements, and composite oxides containing three or more types of metal elements.

[0023] The positive electrode active material may be a coated positive electrode active material having at least a part of its surface coated with a coating material containing a polymer compound. When the positive electrode active material is coated with the coating material, the volume change of the positive electrode is mitigated, and the expansion of the positive electrode can be suppressed.

[0024] As the polymer compound constituting the coating material, those described as active material coating resins in JP 2017-054703 A and WO 2015 / 005117 A, for example, can be suitably used.

[0025] The coating material may contain a conductive agent, which may be the same as the conductive filler contained in the positive electrode current collector layer 21a.

[0026] The positive electrode active material layer 22a may contain an adhesive resin. For example, the adhesive resin may be a resin for coating a non-aqueous secondary battery active material described in JP 2017-054703 A in which a small amount of organic solvent is mixed to adjust the glass transition temperature to room temperature or lower, and a resin described as an adhesive in JP 10-255805 A. The adhesive resin means a resin that does not solidify even when the solvent component is evaporated and dried, and has adhesiveness (the property of adhering by applying a slight pressure without using water, solvent, heat, etc.). On the other hand, the solution-drying type electrode binder used as a binder means a material that dries and solidifies by evaporating the solvent component, thereby firmly adhering and fixing the active materials to each other. Therefore, the above-mentioned binder (solution-drying type electrode binder) and the adhesive resin are different materials.

[0027] The positive electrode active material layer 22a may contain an electrolytic solution containing an electrolyte and a non-aqueous solvent. As the electrolyte, a substance used in a known electrolytic solution can be used. As the non-aqueous solvent, a substance used in a known electrolytic solution (e.g., phosphoric acid ester, nitrile compound, and mixtures thereof) can be used. For example, a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC), or a mixture of ethylene carbonate (EC) and propylene carbonate (PC) can be used.

[0028] The positive electrode active material layer 22a may contain a conductive assistant, which may be a conductive material similar to the conductive filler contained in the positive electrode current collector layer 21a.

[0029] The thickness of the positive electrode active material layer 22a is not particularly limited, but from the viewpoint of battery performance, it is preferably 300 to 750 μm, and more preferably 350 to 600 μm.

[0030] In an embodiment, the positive electrode composition supplied to form the positive electrode active material layer 22a is a wet powder containing a positive electrode active material and a non-aqueous electrolyte solution. The wet powder is more preferably in a pendular or funicular state.

[0031] The proportion of the nonaqueous electrolyte in the wet powder is not particularly limited, but in order to achieve a pendular or funicular state, in the case of a positive electrode, it is desirable that the proportion of the nonaqueous electrolyte be 0.5 to 30% by weight of the entire wet powder.

[0032] <Specific examples of negative electrode current collectors> The negative electrode current collector constituting the negative electrode current collector layer 21b may be appropriately selected from the same configuration as that described for the positive electrode current collector, and may be obtained by the same method. From the viewpoint of battery characteristics, the negative electrode current collector layer 21b is preferably a resin current collector. The thickness of the negative electrode current collector layer 21b is not particularly limited, but is preferably 5 to 150 μm.

[0033] <Specific examples of negative electrode active materials> The negative electrode active material layer 22b is preferably a non-binding material of a mixture containing a negative electrode active material. The reason why the negative electrode active material layer is preferably a non-binding material and the method for obtaining the non-binding negative electrode active material layer 22b are the same as the reason why the positive electrode active material layer 22a is preferably a non-binding material and the method for obtaining the non-binding positive electrode active material layer 22a.

[0034] As the negative electrode active material, for example, a carbon-based material, a silicon-based material, or a mixture thereof can be used, but is not particularly limited.

[0035] The negative electrode active material may be a coated negative electrode active material having at least a part of its surface coated with a coating material containing a polymer compound. When the negative electrode active material is coated with the coating material, the volume change of the negative electrode is mitigated, and the expansion of the negative electrode can be suppressed.

[0036] As the coating material, the same coating material as that constituting the coated positive electrode active material can be suitably used.

[0037] The negative electrode active material layer 22b contains an electrolytic solution containing an electrolyte and a non-aqueous solvent. The composition of the electrolytic solution may be the same as that of the electrolytic solution contained in the positive electrode active material layer 22a.

[0038] The negative electrode active material layer 22b may contain a conductive assistant, which may be the same conductive material as that contained in the positive electrode active material layer 22a.

[0039] The negative electrode active material layer 22b may contain an adhesive resin, which may be the same as the adhesive resin that is an optional component of the positive electrode active material layer 22a.

[0040] The thickness of the negative electrode active material layer 22b is not particularly limited, but from the viewpoint of battery performance, it is preferably 450 to 900 μm, and more preferably 500 to 750 μm.

[0041] In an embodiment, the negative electrode composition supplied to form the negative electrode active material layer 22b is a wet powder containing a negative electrode active material and a non-aqueous electrolyte solution. The wet powder is more preferably in a pendular or funicular state.

[0042] The proportion of the nonaqueous electrolyte in the wet powder is not particularly limited, but in order to achieve a pendular or funicular state, in the case of a negative electrode, it is desirable that the proportion of the nonaqueous electrolyte be 0.20 to 40% by weight of the entire wet powder.

[0043] <Examples of separators> Examples of the electrolyte held in the separator 30 include an electrolytic solution and a gel polymer electrolyte. By using these electrolytes, high lithium ion conductivity is ensured in the separator 30. Examples of the form of the separator 30 include, but are not limited to, a porous film made of polyethylene or polypropylene.

[0044] <Examples of frame bodies> The frame 35 is not particularly limited as long as it is a material that is durable against the electrolyte, but for example, a polymer material is preferable, and a thermoplastic polymer material is more preferable. The material constituting the frame 35 may be any material that has insulation properties, sealing properties (liquid-tightness), heat resistance at the battery operating temperature, electrolyte resistance, etc., and a resin material is preferably used. More specifically, the frame 35 may be, for example, a polyolefin resin, a polyurethane resin, or a polyvinylidene fluoride resin, and the like, and polyolefin resin is preferable because it is highly durable and easy to handle.

[0045] <Battery manufacturing device and battery manufacturing method> Next, a battery manufacturing apparatus and a battery manufacturing method according to the present embodiment will be described. For example, the battery manufacturing apparatus executes a battery manufacturing method described below to manufacture the unit cell 10 shown in FIG.

[0046] FIG. 2A is a schematic diagram of a first manufacturing apparatus 1000A included in the battery manufacturing apparatus. FIG. 2B is a schematic diagram of a second manufacturing apparatus 1000B included in the battery manufacturing apparatus. The first manufacturing apparatus 1000A performs a first step including at least continuously supplying an electrode composition containing an active material to a release film being conveyed and continuously compressing the electrode composition supplied onto the release film. The second manufacturing apparatus 1000B performs a second step including at least introducing the electrode composition separated from the release film and divided into units into an assembly step. The battery manufacturing apparatus manufactures the single cell 10 shown in FIG. 1 by having the first manufacturing apparatus 1000A perform the first step and the second manufacturing apparatus 1000B perform the second step. The first manufacturing apparatus 1000A is an example of a first manufacturing section. The second manufacturing apparatus 1000B is an example of a second manufacturing section.

[0047] For example, as shown in Fig. 2A, the first manufacturing apparatus 1000A includes a chamber 101, a conveying device 210, an electrode composition supplying device 300, and a pressing device 400. In Fig. 2A, the downstream side of the conveying direction of the release film 40B by the conveying device 210 is shown as the +X direction, and the upper side in the vertical direction is shown as the +Y direction.

[0048] The chamber 101 is a room whose interior can be kept at a reduced pressure lower than atmospheric pressure. The interior of the chamber 101 is reduced in pressure to a pressure lower than atmospheric pressure by a vacuum pump (not shown). The standard atmospheric pressure is about 1013 hPa (about 101 kPa).

[0049] The release roll 40R is formed by winding a strip-shaped release film 40B into a roll shape. The conveying device 210 pulls out the release film 40B from the release roll 40R and conveys it in the +X direction. For example, the conveying device 210 conveys the release film 40B by rotating a drive roller (not shown) in contact with the release film 40B. In addition, for example, the conveying device 210 supports the release film 40B from below by a roller or a stage so that the release film 40B does not sag.

[0050] The release roll 40R may be disposed outside the chamber 101. In this case, the release film 40B pulled out from the release roll 40R is transported into the chamber 101 through a slit provided in the chamber 101. The external space of the chamber 101 in which the release roll 40R is disposed may be at normal pressure, or may be reduced in pressure by a chamber different from the chamber 101.

[0051] The electrode composition supplying device 300 continuously supplies the electrode composition 22c to the conveyed release film 40B. Although the specific configuration of the electrode composition supplying device 300 is not particularly limited, as an example, the electrode composition supplying device 300 includes a hopper. That is, the electrode composition supplying device 300 applies the electrode composition 22c held in the hopper to the conveyed release film 40B so as to have a constant thickness.

[0052] A part or the whole of the inner wall of the hopper provided in the electrode composition supplying device 300 may be configured to be a moving belt. That is, the electrode composition 22c in the hopper may be driven in the direction of the release film 40B by rotating the moving belt. As described above, the electrode composition 22c may be a wet powder containing an active material and a nonaqueous electrolyte, and the electrode composition 22c may solidify in the hopper, causing the supply amount of the electrode composition 22c to the release film 40B to become unstable. In response to this, the electrode composition supplying device 300 can stabilize the supply amount of the electrode composition 22c to the release film 40B by driving the electrode composition 22c by the moving belt.

[0053] The press device 400 continuously compresses the electrode composition 22c supplied onto the release film 40B. For example, the press device 400 has an upper roller 401 and a lower roller 402 as shown in Fig. 2A. The press device 400 sandwiches and compresses the electrode composition 22c supplied onto the release film 40B with the upper roller 401 and the lower roller 402. That is, the press device 400 performs roll pressing on the electrode composition 22c.

[0054] When performing the roll press, a release film different from the release film 40B may be further used to suppress adhesion of the electrode composition 22c to the roller. For example, a release film wound in a roll shape is pulled out in synchronization with the conveying speed of the electrode composition 22c and is laid on the upper surface of the electrode composition 22c before the roll press. As a result, the roll press is performed in a state in which the release film is sandwiched between the upper roller 401 and the electrode composition 22c, thereby suppressing adhesion of the electrode composition 22c to the upper roller 401. The release film after the roll press is peeled off from the electrode composition 22c and can be collected, for example, by winding it up in a roll shape.

[0055] 2A, a belt-shaped member consisting of release film 40B and electrode composition 22c after compression by press device 400 is referred to as member 41B. First manufacturing apparatus 1000A winds up member 41B to manufacture member roll 41R. As described above, the various processes performed by first manufacturing apparatus 1000A are executed as a continuous series of lines.

[0056] Next, the second manufacturing apparatus 1000B will be described. For example, as shown in Fig. 2B, the second manufacturing apparatus 1000B includes a chamber 102, a conveying apparatus 220, a dividing apparatus 500, and a transfer apparatus 600. In Fig. 2B, the downstream side of the conveying direction of the member 41B by the conveying apparatus 220 is shown as the +X' direction, and the upper side in the vertical direction is shown as the +Y direction. The +X' direction may coincide with or be different from the +X direction shown in Fig. 2A.

[0057] Similar to the chamber 101, the chamber 102 is a room whose interior can be maintained at a pressure lower than atmospheric pressure.

[0058] The member roll 41R shown in Fig. 2B is manufactured by the first manufacturing apparatus 1000A as described above, and is transported into the chamber 102. For example, a storage room is provided for storing the member roll 41R manufactured by the first manufacturing apparatus 1000A, and each time the member roll 41R is consumed in the second manufacturing apparatus 1000B, the member roll 41R is transported from the storage room into the chamber 102. Note that it is also possible to omit the storage room for the member roll 41R by having the first manufacturing apparatus 1000A manufacture the member roll 41R in response to consumption of the member roll 41R by the second manufacturing apparatus 1000B.

[0059] The transport device 220 pulls out the component 41B from the component roll 41R and transports it in the +X' direction. For example, the transport device 220 transports the component 41B by rotating a drive roller (not shown) in contact with the component 41B. Also, for example, the transport device 220 supports the component 41B from below with a roller or a stage to prevent bending of the component 41B.

[0060] Here, the second manufacturing equipment 1000B peels off the release film 40B from the member 41B. That is, the second manufacturing equipment 1000B separates the release film 40B from the electrode composition 22c. The release film 40B separated from the electrode composition 22c is gathered into a release roll 41R' shown in FIG. 2, for example, and appropriately transported to the outside of the chamber 102. The transport device 220 continues to transport the electrode composition 22c separated from the release film 40B in the +X' direction.

[0061] Next, the dividing apparatus 500 divides the electrode composition 22c into units. Here, the division unit corresponds to, for example, the single cell 10 shown in Fig. 1. That is, the dividing apparatus 500 divides the electrode composition 22c according to the dimensions of the electrode active material layer 22 in the single cell 10 shown in Fig. 1. For example, the dividing apparatus 500 divides the electrode composition 22c into units using a laser cutter.

[0062] Hereinafter, the electrode composition 22c separated from the release film 40B and divided into units by the dividing device 500 will also be referred to as an electrode composition 22c'. The transfer device 600 introduces the electrode composition 22c' into the assembly process of the unit cell 10.

[0063] The assembly process may be performed by the second manufacturing apparatus 1000B, or may be performed in another apparatus (not shown). That is, the second process performed by the second manufacturing apparatus 1000B may or may not include the assembly process. For example, the second manufacturing apparatus 1000B performs the assembly process for the electrode composition 22c' introduced to the assembly process by the transfer apparatus 600. Alternatively, the second manufacturing apparatus 1000B introduces the electrode composition 22c' by the transfer apparatus 600 to another apparatus that performs the assembly process.

[0064] For example, the second manufacturing apparatus 1000B performs the assembly step in the chamber 102 shown in Fig. 2B. Alternatively, the second manufacturing apparatus 1000B may perform the step of peeling the release film 40B from the member 41B and the step of dividing the electrode composition 22c into units in the chamber 102, and may perform the assembly step in another chamber different from the chamber 102, the inside of which is depressurized below atmospheric pressure.

[0065] Although the specific embodiment of the assembly process of the unit cell 10 is not particularly limited, as an example, the positive electrode 20a and the negative electrode 20b are first produced. For example, when the electrode composition 22c' is a positive electrode active material, the positive electrode 20a can be produced by supplying the positive electrode collector layer 21a and the frame 35 to the electrode composition 22c'. When the electrode composition 22c' is a negative electrode active material, the negative electrode 20b can be produced by supplying the negative electrode collector layer 21b and the frame 35 to the electrode composition 22c'.

[0066] After the positive electrode 20a and the negative electrode 20b are manufactured, the positive electrode 20a and the negative electrode 20b are stacked with the separator 30 interposed therebetween to manufacture the single cell 10. For example, the single cell 10 can be manufactured by supplying the separator 30 to the surface of the positive electrode 20a facing the positive electrode active material layer 22a, and further supplying the negative electrode 20b so that the separator 30 and the negative electrode active material layer 22b are in contact with each other. Alternatively, the single cell 10 can be manufactured by supplying the separator 30 to the surface of the negative electrode 20b facing the negative electrode active material layer 22b, and further supplying the positive electrode 20a so that the separator 30 and the positive electrode active material layer 22a are in contact with each other.

[0067] The assembly process of the unit cell 10, such as manufacturing the positive electrode 20a and the negative electrode 20b and stacking the positive electrode 20a, the negative electrode 20b, and the separator 30, is performed in a state in which the unit cell 10 is divided into units. That is, the assembly process of the unit cell 10 is performed on a sheet-by-sheet basis.

[0068] As described above, the battery manufacturing apparatus of the embodiment includes a first manufacturing apparatus 1000A for performing the first step shown in FIG. 2A and a second manufacturing apparatus 1000B for performing the second step shown in FIG. 2B. The first step includes continuously supplying an electrode composition 22c containing an active material to a conveyed release film 40B, and continuously compressing the electrode composition 22c supplied onto the release film 40B. The second step includes introducing the electrode composition 22c' separated from the release film 40B and divided into units into an assembly process. This allows the battery manufacturing apparatus to improve the manufacturing efficiency of batteries.

[0069] In general, the latter part of the assembly process of the single cell 10, such as stacking the positive electrode 20a, the negative electrode 20b, and the separator 30, must be performed on a sheet-by-sheet basis. Compared with the processes of supplying and compressing the electrode composition, which are performed continuously, the assembly process performed on a sheet-by-sheet basis takes time, and if all the processes are performed on a continuous line, the assembly process becomes a bottleneck and the battery manufacturing efficiency decreases. In order to improve the battery manufacturing efficiency, it is also possible to prepare multiple assembly process lines for performing the assembly process, and to distribute the electrode composition that has been continuously subjected to the processes of supplying and compressing to the multiple assembly process lines. However, when such a method is adopted, there is a risk that the entire line, including the processes of supplying and compressing the electrode composition, will stop due to a malfunction of one of the multiple assembly process lines.

[0070] In contrast, in the battery manufacturing apparatus of the embodiment, the first step including supplying and compressing the electrode composition and the second step including introduction to the assembly process are assigned to different devices. The first manufacturing apparatus 1000A can continuously and efficiently execute the steps of supplying and compressing the electrode composition. The second manufacturing apparatus 1000B executes the assembly process of the unit cell 10 one by one. Even if a malfunction occurs in the second manufacturing apparatus 1000B and the line performing the assembly process of the unit cell 10 is stopped, the first step by the first manufacturing apparatus 1000A is not affected. In this way, the battery manufacturing apparatus of the embodiment can improve the manufacturing efficiency of the battery by appropriately dividing a series of steps from supplying the electrode composition to assembling the cell 10.

[0071] In the battery manufacturing apparatus of the embodiment, various processes are performed by the first manufacturing apparatus 1000A and the second manufacturing apparatus 1000B in the chamber 101 or the chamber 102, the inside of which is depressurized below atmospheric pressure. This makes it possible to prevent air from remaining and improve the uniformity of the electrode active material layer 22.

[0072] As described above, the electrode composition supplying device 300 continuously supplies the electrode composition 22c to the conveyed release film 40B, and then divides the electrode composition 22c into units. Here, by intermittently supplying the electrode composition 22c according to the dimensions of the electrode active material layer 22 in the single cell 10, it is possible that the shape of the electrode composition 22c may be adjusted at the stage of supplying the electrode composition 22c.

[0073] However, when the electrode composition 22c is supplied intermittently, the supply is repeatedly started and stopped, and the electrode composition 22c may scatter or the basis weight may become unstable at the ends (start end and end). In addition, in order to realize the intermittent supply of the electrode composition 22c, a mechanical structure is required, for example, a shutter that opens and closes the opening of the hopper. Such a mechanical structure has a limited life due to wear and tear, so regular maintenance and replacement of parts are required, which is undesirable in terms of manufacturing efficiency and cost.

[0074] In contrast, the electrode composition supplying device 300 of the embodiment can improve the accuracy of supplying the electrode composition 22c to the release film 40B by continuously supplying. Specifically, it is possible to avoid cases where the electrode composition 22c scatters at the starting end and the ending end, or where the basis weight becomes unstable, and by keeping the electrode composition 22c in a constantly flowing state inside the hopper, it is possible to suppress the adhesion of the electrode composition in the hopper. This makes it possible to stabilize the supply of the electrode composition 22c and improve the quality of the coated surface of the electrode composition 22c on the release film 40B. Furthermore, unlike the case where the electrode composition 22c is supplied intermittently, it is only necessary to keep the coating thickness constant, and therefore feedback control of the coating thickness can be easily realized.

[0075] As described above, the press device 400 continuously compresses the electrode composition 22c continuously supplied onto the release film 40B. The press device 400 of the embodiment compresses a continuum having a substantially constant coating thickness, and therefore the accuracy of compression can be improved compared to the case where the electrode composition 22c is intermittently supplied. For example, it is possible to avoid the case where the electrode composition 22c is scattered at the start and end. Unlike the case where the electrode composition 22c is intermittently supplied, the press thickness of the electrode composition 22c after compression only needs to be constant, and therefore feedback control of the press thickness can be easily realized.

[0076] In the embodiment, an example in which the electrode composition 22c is supplied to the release film 40B has been described, but it is possible to use a collector sheet formed by forming a collector into a strip shape instead of the release film 40B. In the case of using a collector sheet instead of the release film 40B, the press device 400 of the first manufacturing equipment 1000A sandwiches and compresses the collector sheet and the electrode composition 22c. In the second manufacturing equipment 1000B, the process of peeling the release film 40B from the compressed electrode composition 22c is omitted. In addition, the dividing device 500 of the second manufacturing equipment 1000B divides the collector sheet and the electrode composition 22c into units.

[0077] However, in cases where a current collector sheet is used instead of the release film 40B, the current collector sheet may be damaged during various steps or transportation, which may result in a decrease in the quality of the current collector layer 21 in the single cell 10. For example, since high tension cannot be applied to the current collector sheet, it is necessary to support the current collector sheet with rollers or a stage to prevent bending. These rollers or stages may rub against the current collector sheet, causing damage to the current collector sheet.

[0078] Furthermore, in the case where a current collector sheet is used instead of release film 40B, dividing device 500 cuts current collector sheet and electrode composition 22c together to the same dimensions. As a result, after cutting, there is no protruding portion of the current collector on the cut side for placing frame 35 thereon, so a step of peeling off electrode composition 22c from this portion is required.

[0079] In contrast, in the battery manufacturing apparatus of the embodiment, the electrode composition 22c is supplied to the release film 40B, so the quality of the current collector layer 21 in the unit cell 10 is guaranteed. In addition, any material can be selected for the release film 40B, and since it is collected before the assembly of the unit cell 10, it is also possible to compress the electrode composition 22c by the press device 400 at high temperature and high pressure. This can improve the strength of the electrode composition 22c after compression and increase the density of the electrode active material layer 22 in the unit cell 10. As a result, the internal resistance in the unit cell 10 can be reduced, and the energy density can be improved.

[0080] In the battery manufacturing apparatus of the embodiment, the dividing device 500 divides the electrode composition 22c. That is, unlike the case where a collector sheet is used instead of the release film 40B described above, the dividing target is only the electrode composition 22c. This also makes it possible to create a state in which the electrode active material layer 22 is alone, and therefore makes it possible to apply an electrolyte solution to the interface when forming the positive electrode 20a or the negative electrode 20b.

[0081] Furthermore, unlike the case where the shape of the electrode composition 22c is adjusted at the stage of supplying the electrode composition 22c, the dividing device 500 can accurately adjust the shape of the electrode composition 22c without being affected by the accuracy of supply by the electrode composition supplying device 300 or the change in shape when compressed by the pressing device 400.

[0082] As described above, the second manufacturing apparatus 1000B divides the electrode composition 22c by a laser cutter. At this time, it is possible to harden the resin on the cut surface to prevent the electrode composition 22c from scattering.

[0083] The electrode composition 22c may be divided using a cut roll having teeth of a predetermined shape. In contrast, when the electrode composition 22c is divided using a laser cutter, maintenance such as periodic replacement of the teeth of the cut roll is not required, making it suitable for mass production. When the electrode composition 22c is divided using a laser cutter, the shape of the electrode composition 22c after division can be appropriately adjusted. For example, with a laser cutter, it is possible to easily realize the cut size, etc. by changing the settings, whether or not to cut the edge ends or to apply R processing (chamfering) to the corners.

[0084] The above-described embodiment is merely an example, and various modifications are possible.

[0085] For example, in the above-described embodiment, an example was described in which the member roll 41R is manufactured in the first step, and in the second step, the release film 40B and the electrode composition 22c are pulled out from the member roll 41R, the release film 40B and the electrode composition 22c are separated, and the electrode composition 22c is divided into units. That is, an example was described in which the electrode composition 22c is transferred from the first step to the second step in the form of the member roll 41R. However, the embodiment is not limited to this.

[0086] For example, in Fig. 2A and Fig. 2B, an example has been described in which the second manufacturing apparatus 1000B performs the step of separating the release film 40B from the electrode composition 22c, but this step may be performed in the first manufacturing apparatus 1000A. Specifically, in the first step, the first manufacturing apparatus 1000A separates the electrode composition 22c compressed by the press device 400 from the release film 40B. Furthermore, in the first step, the first manufacturing apparatus 1000A winds up the electrode composition 22c separated from the release film 40B to manufacture a member roll. Then, in the second step, the second manufacturing apparatus 1000B pulls out the electrode composition 22c from the member roll and divides the electrode composition 22c into units using the dividing device 500.

[0087] Also, for example, in the first step, the first manufacturing apparatus 1000A separates the electrode composition 22c compressed by the press device 400 from the release film 40B. Furthermore, in the first step, the first manufacturing apparatus 1000A divides the electrode composition 22c separated from the release film 40B into units to manufacture divided electrode compositions. For example, the first manufacturing apparatus 1000A can divide the electrode composition 22c using an apparatus similar to the dividing apparatus 500 to manufacture divided electrode compositions. For example, the first manufacturing apparatus 1000A divides the electrode composition 22c into units using a laser cutter. The divided electrode composition may be the divided electrode composition 22c' itself, or may be the electrode composition 22c' packaged in a storage film or container. Then, in the second step, the second manufacturing apparatus 1000B introduces the divided electrode composition into the assembly step of the single cell 10. For example, when the divided electrode composition is packaged, the second manufacturing apparatus 1000B takes out the electrode composition 22c' from the divided electrode composition and introduces it into the assembly process.

[0088] In the above-mentioned embodiment, the various steps are performed in chambers such as chamber 101 and chamber 102, but the embodiment is not limited to this. That is, the above-mentioned chambers can be divided or omitted as appropriate. For example, FIG. 2A shows an example in which the first step is performed in chamber 101, but each step included in the first step may be performed in a separate chamber. Similarly, FIG. 2B shows an example in which the second step is performed in chamber 102, but each step included in the second step may be performed in a separate chamber. Also, chambers such as chamber 101 and chamber 102 can be omitted. That is, some or all of the various steps included in the first step and second step may be performed outside the chamber. By omitting the chamber, even if scraps and other waste are generated, they can be easily collected.

[0089] For example, the second manufacturing apparatus 1000B may perform only the assembly process in the chamber. As an example, the second manufacturing apparatus 1000B may perform only the process of bonding the positive electrode 20a and the negative electrode 20b in the chamber among the assembly processes. That is, the second manufacturing apparatus 1000B may perform only the bonding process of the positive and negative electrodes in the chamber, and may perform the process of supplying a current collector layer, a frame, and a separator to the electrode composition 22c' outside the chamber. As another example, the second manufacturing apparatus 1000B may perform the entire assembly process including the process of supplying a current collector layer, a frame, and a separator to the electrode composition 22c' and the bonding process of the positive and negative electrodes in the chamber.

[0090] Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the changes, combinations, deletions, etc. of the configurations within the scope of the present invention are also included. Furthermore, it goes without saying that the configurations shown in each embodiment can be used in appropriate combination. When the lithium ion secondary battery exemplified in the above description is used among the secondary batteries, it includes a battery using a liquid material for the electrolyte and a battery using a solid material for the electrolyte (so-called all-solid-state battery). Furthermore, the battery in this embodiment includes a battery having a metal foil (metal current collector foil) as a current collector, and includes a battery having a so-called resin current collector made of a resin to which a conductive material has been added instead of the metal foil. When the resin current collector is used as a resin current collector for a bipolar electrode, a positive electrode may be formed on one side of the resin current collector and a negative electrode may be formed on the other side to form a bipolar electrode. The battery in this embodiment includes a battery in which an electrode is formed by applying a positive or negative electrode active material, etc. to a positive or negative electrode current collector, respectively, using a binder, and in the case of a bipolar battery, includes a battery in which a bipolar electrode is formed by applying a positive electrode active material, etc. to one side of a current collector using a binder to form a positive electrode layer, and applying a negative electrode active material, etc. to the opposite side using a binder to form a negative electrode layer. [Explanation of symbols]

[0091] 10: Single cell 20: Electrode 20a: Positive electrode 20b: Negative electrode 21: Current collector layer 21a: Positive electrode current collector layer 21b: Negative electrode current collector layer 22: Electrode active material layer 22a: Positive electrode active material layer 22b: Negative electrode active material layer 22c: Electrode composition 30: Separator 35:Frame body 40B: Release film 40R: Release roll 41B: Materials 41R: Material roll 41R': Release roll 101: Chamber 102: Chamber 210: Transport device 220:Transportation device 300: Electrode composition supply device 400: Press equipment 500: Splitting device 600: Transfer device 1000A: 1st manufacturing equipment 1000B:Second manufacturing equipment

Claims

1. A first manufacturing unit that executes a first step including at least continuously supplying an electrode composition containing an active material to a release film being transported, and continuously compressing the electrode composition supplied onto the release film; a second manufacturing unit that performs a second step including at least introducing the electrode composition separated from the release film and divided into units into an assembly step; A battery manufacturing apparatus comprising:

2. The battery manufacturing apparatus according to claim 1 , wherein the second manufacturing section performs the assembly process in a first chamber the inside of which is reduced in pressure below atmospheric pressure.

3. the first step includes winding up the release film and the compressed electrode composition to produce a member roll; 2. The battery manufacturing apparatus according to claim 1, wherein the second step includes pulling out the release film and the electrode composition from the member roll, separating the release film and the electrode composition, and dividing the electrode composition into the units.

4. The second manufacturing department comprises: The assembly step is carried out in a first chamber the inside of which is reduced in pressure below atmospheric pressure; 4. The battery manufacturing apparatus according to claim 3, wherein the steps of pulling out the release film and the electrode composition from the member roll, separating the release film and the electrode composition, and dividing the electrode composition into units are performed in the first chamber or in a second chamber different from the first chamber and the inside of which is reduced in pressure below atmospheric pressure.

5. The battery manufacturing apparatus according to claim 4 , wherein the first manufacturing section performs the first step in another chamber different from the first chamber and the second chamber, the inside of which is reduced in pressure below atmospheric pressure.

6. The battery manufacturing apparatus according to claim 3 , wherein the second manufacturing section divides the electrode composition into the units using a laser cutter.

7. The first step includes separating the release film from the compressed electrode composition and dividing the electrode composition into the units to produce a divided electrode composition, The battery manufacturing apparatus according to claim 1 , wherein the second step includes introducing the divided electrode composition into the assembly step.

8. The first step includes separating the release film from the compressed electrode composition, and winding up the electrode composition separated from the release film to produce a member roll, The battery manufacturing apparatus according to claim 1 , wherein the second step includes drawing out the electrode composition from the member roll and dividing it into the units.

9. A first step is carried out, the first step including: continuously supplying an electrode composition containing an active material to a release film being conveyed; and continuously compressing the electrode composition supplied onto the release film; A second step is carried out, which includes at least introducing the electrode composition separated from the release film and divided into units into an assembly process. A method for manufacturing a battery comprising:

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