JP5492686B2 - Battery electrode manufacturing method, battery manufacturing method, battery, vehicle, and electronic device - Google Patents

Description

  The present invention relates to a technical field of a battery in which an electrolyte layer is interposed between active material layers, and more particularly to a battery electrode and a battery manufacturing method, a battery, and a vehicle and an electronic device using the battery.

  For example, as a method of manufacturing a chemical battery such as a lithium ion secondary battery, conventionally, a metal foil as a current collector to which a positive electrode active material and a negative electrode active material are attached is overlapped via a separator, and the separator is used as a separator. A technique for impregnating an electrolytic solution is known. However, since batteries that contain highly volatile organic solvents as electrolytes need to be handled with care, and further downsizing and higher output are required, in recent years, instead of electrolytes, solid electrolytes have been used. Techniques for manufacturing all solid state batteries by microfabrication have been proposed.

  For example, in the battery electrode manufacturing technology described in Patent Document 1, a current collector having a partially convex surface is formed by discharging droplets containing a metal material onto a metal foil by an inkjet method. By embedding this in the active material layer, the contact area between the current collector and the active material is increased to reduce the internal resistance of the battery.

Japanese Patent Laying-Open No. 2010-040277 (for example, FIG. 2)

  In order to improve the performance as a battery, it is necessary to increase not only the contact area between the current collector and the active material but also the opposing area between the positive and negative active materials via the electrolyte layer. However, in the battery electrode of the above prior art, the surface of the active material layer in which the current collector is embedded is formed almost flat, and its surface area is limited with respect to the amount of active material used. It did not reach the full performance as a battery. In particular, there is room for improvement in the above prior art in that a battery having excellent charge / discharge characteristics is made compact.

  The present invention has been made in view of the above problems, and is a battery in which an electrolyte layer is interposed between active material layers. The battery has a small size and excellent characteristics, and a vehicle and an electronic device using the battery are configured. The purpose is to provide technology that can be used.

In order to achieve the above object, the battery electrode manufacturing method according to the present invention applies a coating liquid containing a conductive material to the surface of the base material, and the surface opposite to the surface in contact with the base material is uneven. A current collector layer forming step for forming a current collector layer, and a coating liquid containing an active material material is applied to the surface of the current collector layer to have irregularities following the irregularities on the surface of the current collector layer An active material layer forming step for forming an active material layer, and in the current collector layer forming step, a coating liquid containing the conductive material is linearly discharged from a nozzle that moves relative to the surface of the base material. Thus, the current collector layer comprising a plurality of linear patterns parallel to each other is formed .

  In the invention configured as described above, it is possible to manufacture a battery electrode in which a current collector layer having an uneven surface on a base material and an active material layer having an uneven surface following the unevenness are further laminated. it can. In the battery electrode thus formed, not only the current collector layer and the active material layer have a wide contact area, but also the surface of the active material layer opposite to the side in contact with the current collector layer has irregularities. Since the surface area is wide, it is possible to increase the contact area with the electrolyte in contact with this surface. For this reason, the battery using this battery electrode can be made small and have high performance, particularly good charge / discharge characteristics.

This collector layer formation step, a coating solution containing a conductive material from a nozzle moving relative to the surface of the substrate by ejecting the linear collector layer consisting of a plurality of parallel linear patterns each other you form. By applying such a so-called nozzle scanning method as a coating method, a current collector layer having a large thickness, that is, a large unevenness level difference and a large surface area can be formed by one scan.

  In this case, for example, in the active material layer forming step, the coating liquid containing the active material is linearly discharged from the second nozzle that moves relative to the surface of the base material along the linear pattern of the current collector layer. Then, an active material layer covering the surface of the linear pattern may be formed. By relatively moving the second nozzle along the linear pattern of the current collector layer, an active material layer covering the surface of the current collector layer can be formed in a short time.

  Further, for example, in the active material layer forming step, an active material layer that covers both the surface of the linear pattern of the current collector layer and the surface of the base material exposed between the linear patterns may be formed. By doing so, the surface area of the active material layer can be further increased.

  In this case, in the active material layer forming step, for example, a coating liquid containing an active material is poured onto the surface of the base material exposed between the linear patterns of the current collector layer, and further, the surface of the base material is aligned along the linear pattern. On the other hand, the active material layer that covers the surface of the base material and the surface of the linear pattern may be formed by discharging a coating liquid containing the active material material linearly from the second nozzle that moves relative to the second nozzle. In this way, the coating liquid is first poured into the exposed substrate surface, and then the coating liquid is applied so as to cover the linear pattern, so that the coating liquid applied to the linear pattern flows from the top of the pattern to the surroundings. It is possible to prevent the apex from being exposed by spreading.

  In these cases, the thickness of the active material layer covering the surface of the base material may be smaller than or equal to the height of the linear pattern of the current collector layer. By making the thickness of the active material layer smaller than the pattern height difference of the current collector layer, the side surface of the linear pattern can be used effectively. In addition, when the thickness of the active material layer is approximately the same as the height of the linear pattern of the current collector layer, when the coating liquid is applied so as to cover the linear pattern, the coating liquid has a linear pattern. It is prevented from flowing down from the top.

  In these inventions, the surface of the base material on which the current collector layer is formed may be conductive, or may be composed of an active material having the same polarity as the active material constituting the active material layer. Good. When the surface of the base material on which the current collector layer is formed has conductivity, the surface of the base material and the current collector layer can function integrally as a current collector. Moreover, when comprised by an active material, a base-material surface and an active material layer can be functioned as an active material layer integrally.

  Furthermore, in this invention, since the current collector layer and the active material layer are sequentially formed on the base material, the base material itself may be an insulator. As described above, in the present invention, battery electrodes can be formed on various substrate surfaces. For example, battery electrodes can be formed in a housing or a substrate of an electronic device.

  In order to achieve the above object, the battery manufacturing method according to the present invention has an electrolyte layer and a second active material layer on the active material layer side surface of the battery electrode manufactured by any of the manufacturing methods described above. The second current collector layer is laminated in this order. In the invention thus configured, since the active material layer has a large surface area as described above, a functional layer below the electrolyte layer is sequentially laminated on the active material layer, whereby a small and high-performance battery can be produced with excellent productivity. It is possible to manufacture with.

  In this case, for example, an application layer containing an electrolyte material is applied to the active material layer to form an electrolyte layer having irregularities following the irregularities on the surface of the active material layer, and a second active layer is formed on the electrolyte layer. A second active material in which a coating liquid containing a material is applied to form a second active material layer in which the surface in contact with the electrolyte layer has irregularities imitating the irregularities on the surface of the electrolyte layer, while the opposite surface is substantially flat A layer forming step. In such a configuration, since the electrolyte layer has an uneven structure that follows the unevenness of the active material layer, it is possible to manufacture a battery having a large facing area between the active material layer and the second active material layer and good charge / discharge characteristics. It becomes possible.

In order to achieve the above object, the battery according to the present invention has a base material, a first current collector layer having irregularities on the surface opposite to the surface in contact with the base material, and the first current collector layer. A first active material layer having unevenness following the surface unevenness, an electrolyte layer having unevenness following the unevenness on the surface of the first active material layer, and a surface in contact with the electrolyte layer following the unevenness on the surface of the electrolyte layer. and one having an uneven, the opposite second active material layer surface is substantially flat, and a second current collector layer, have a structure formed by laminating in this order, one of the battery production method described above It is characterized by being manufactured by In the invention configured as described above, it is possible to configure a battery that is small, has high performance, and can be manufactured with excellent productivity.

  In this case, the first current collector layer may include a plurality of linear patterns extending in parallel to each other in a predetermined direction. Since the first current collector layer having such a pattern has a large surface area with respect to the amount of material used, the contact area with the first active material layer can be increased. Further, such a pattern can be manufactured by, for example, a nozzle scanning method, and a fine pattern can be formed.

  The vehicle according to the present invention is characterized in that a battery manufactured by the above manufacturing method is mounted in order to achieve the above object. Furthermore, in order to achieve the above object, an electronic device according to the present invention is manufactured by the above manufacturing method using the circuit unit, a housing that holds the circuit unit, and the housing as the base material. And a battery for supplying electric power. In these inventions, various vehicles or electronic devices equipped with small and high-performance batteries can be configured. In addition, by incorporating the battery into the housing of the electronic device, the electronic device itself can be configured in a small size.

  According to the present invention, the battery electrode is configured by laminating a current collector layer having a concavo-convex pattern and a large surface area, and a current collector layer having concavo-convex following the concavo-convex pattern. By using the electrode, it is possible to configure a small-sized battery with high performance and good productivity and an electronic device using the battery.

It is a flowchart which shows one Embodiment of the manufacturing method of the battery electrode concerning this invention. It is a figure which shows typically the mode of the electrically conductive paste application | coating by a nozzle scan method. It is a figure which shows typically the mode of negative electrode active material coating liquid application | coating by the nozzle scan method. It is a figure which illustrates the cross-section of the electrode for negative electrodes manufactured by the manufacturing method of FIG. It is a figure which shows the 1st modification of the manufacturing method of the battery electrode of FIG. It is a figure which shows an example of the structure for electrically conducting copper foil and a negative electrode electrical power collector. It is a figure which shows the 2nd modification of the manufacturing method of the battery electrode of FIG. It is a figure which shows an example of the structure for electrically connecting between electrical power collectors. It is a flowchart which shows one Embodiment of the manufacturing method of the battery concerning this invention. It is a figure which shows an example of the battery manufactured by the manufacturing method of FIG. It is a figure which shows typically the vehicle as an example of the apparatus carrying the battery concerning this invention. It is a figure which shows an example of the electronic device to which the battery concerning this invention is applied.

  FIG. 1 is a flowchart showing an embodiment of a method for manufacturing a battery electrode according to the present invention. This manufacturing method is a manufacturing method for manufacturing, for example, an electrode that acts as an electrode of a lithium ion secondary battery and is formed by integrally stacking a current collector and an active material. Although a detailed manufacturing process will be described later, an outline of the manufacturing method will be described first. In addition, although the case where the electrode for negative electrodes is manufactured is illustrated below, also in manufacture of the electrode for positive electrodes, it is possible to change the material and to apply the same process.

  First, a base material for a negative electrode is prepared (step S101). As will be described later, either a conductor or an insulator can be used as the base material. Then, a conductive paste containing a conductive material functioning as a negative electrode current collector is applied to one surface of the substrate by an appropriate application method, for example, a nozzle scan method, and a negative electrode current collector having a predetermined uneven pattern A layer is formed (step S102).

  The pattern of the negative electrode current collector is not particularly limited, but here a negative electrode current collector layer having a so-called line-and-space structure in which a plurality of lines made of a conductive paste applied in a line is arranged in parallel with each other is formed. To do. In the following description, the direction orthogonal to the substrate surface is defined as the Z direction, the extending direction of the lines using the conductive paste is defined as the Y direction, and the arrangement direction of the lines is defined as the X direction.

  Furthermore, a negative electrode active material coating liquid containing a negative electrode active material is applied so as to cover the surface of the negative electrode current collector layer having a concavo-convex pattern formed in this way, so as to follow the unevenness of the negative electrode current collector layer (follow-up) A negative active material layer having irregularities is formed (step S103). In this way, the negative electrode is manufactured.

As an electrically conductive paste, what contains copper powder, an organic binder, an organic solvent, etc. as an electroconductive material which functions as a negative electrode electrical power collector can be used. As the negative electrode active material coating solution, for example, an organic LTO material mainly composed of Li ₄ Ti ₅ O ₁₂ (LTO) as a negative electrode active material can be used. In addition to the negative electrode active material, the coating solution includes acetylene black or ketjen black as a conductive auxiliary agent, polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), polyvinyl pyrrolidone (PVP), polyvinyl as a binder. A mixture of alcohol (PVA) or polytetrafluoroethylene (PTFE), N-methyl-2-pyrrolidone (NMP) as a solvent, or the like can be used. As the negative electrode active material, it is possible to use, for example, graphite, metallic lithium, SnO ₂ , an alloy system, etc. in addition to the above LTO.

  FIG. 2 is a diagram schematically showing a state of applying the conductive paste by the nozzle scanning method. More specifically, FIG. 2 (a) is a view of the state of application by the nozzle scanning method as seen from the X direction, and FIGS. 2 (b) and 2 (c) are views of the same state as seen from the Y direction and obliquely from above. It is. A technique for applying a coating solution to a substrate by a nozzle scanning method is known, and such a known technique can also be applied to this method, and thus the description of the apparatus configuration is omitted.

  In the nozzle scanning method, a coating liquid containing a material to be coated is disposed above the substrate 10 with a nozzle 31 having one or a plurality of ejection ports 311, and a certain amount of coating liquid 32 is ejected from the ejection port 311. The nozzle 31 is scanned and moved at a constant speed relative to the substrate 10 in the arrow direction Dn. By doing so, the coating liquid 32 is applied on the substrate 10 in a line shape along the Y direction. By providing a plurality of discharge ports 311 in the nozzle 31, a plurality of stripes can be formed by a single scanning movement, and by repeating the scanning movement as necessary, the coating liquid is formed in a line on the entire surface of the substrate 10. Can be applied. By drying and curing this, the negative electrode current collector layer 11 having a line pattern is formed on the upper surface of the substrate 10. Moreover, drying may be promoted by heating after coating, or a photocurable resin may be added to the coating solution and cured by light irradiation after coating. The nozzle scanning method described above can also be employed when applying a negative electrode active material coating solution, as will be described below.

  FIG. 3 is a diagram schematically showing a state of applying the negative electrode active material coating liquid by the nozzle scanning method. More specifically, FIG. 3A shows a state when the coating liquid is applied to the surface of the negative electrode current collector layer, and FIG. 3B shows a state when the coating liquid is applied to the exposed surface of the substrate. Show. The nozzle 33 provided with the discharge ports 331 at the same pitch as the discharge ports 311 of the nozzle 31 used for applying the conductive paste is disposed above the substrate 10 after the negative electrode current collector layer 11 is formed. Then, the nozzle 33 is scanned and moved in the direction Dn, so that the discharge port 331 is moved along the line pattern 11 by the negative electrode current collector on the substrate 10. By doing so, it is possible to form the negative electrode active material layer 12 covering the surface of the negative electrode current collector layer 11 having a line pattern, as shown in FIG.

  Further, as shown in FIG. 3B, the discharge port 341 of the nozzle 34 whose opening pitch is the same as the discharge port 311 of the nozzle 31 is displaced in the X direction by about ½ of the arrangement pitch of the line pattern. If the scanning movement is performed in the above state, the negative electrode active material coating solution can be applied to the exposed surface 10a of the substrate 10 exposed between the line-shaped patterns to form the negative electrode active material layer 12.

  FIG. 4 is a diagram illustrating a cross-sectional structure of the negative electrode manufactured by the manufacturing method of FIG. In the example shown in FIG. 4A, a negative electrode current collector layer 111 and a negative electrode active material layer 121 are laminated on the surface of a base material 101 made of a material that can function as a negative electrode current collector, for example, copper foil. . In this example, the base material 101 and the negative electrode current collector layer 111 integrally function as a negative electrode current collector. Therefore, since the current collector has a large area and charges can be collected efficiently, an electrode with low internal resistance can be configured.

  In the example shown in FIG. 4B, the copper foil is used as the base material 102, and the negative electrode current collector layer 112 is laminated thereon, which is the same as the example in FIG. The material layer 122 includes a flat portion 122 a that covers the exposed surface 102 a of the substrate 102 that is not covered by the negative electrode current collector layer 112, and a convex portion 122 b that covers the top of the negative electrode current collector layer 112. In the vicinity of the exposed surface 102a of the base material 102, the space between the line-shaped patterns constituting the negative electrode current collector layer 112 is filled with the flat portion 122a of the negative electrode active material layer. That is, the thickness T2 of the flat portion 122a of the negative electrode active material layer covering the exposed surface 102a of the substrate 102 is approximately the same as the height H2 of the negative electrode current collector layer 112.

  Furthermore, the convex part 122b by a negative electrode active material is formed so that the top part of the negative electrode collector layer 112 may be covered. In this structural example, since the volume of the negative electrode active material is large, the amount of charge that can be accumulated is large, and a high-capacity electrode can be configured. In addition, since the contact area between the negative electrode current collector and the negative electrode active material is large, the resistance can be reduced.

  In the example shown in FIG. 4C, the copper foil is used as the base material 103, and the exposed surface 103a of the base material 103 between the negative electrode current collector layers 113 is covered with the flat portion 123a of the negative electrode active material layer 123. This is the same as the example in FIG. 4B in that the top of the negative electrode current collector layer 113 is covered with the convex portion 123b of the negative electrode active material layer 123. However, the flat portion 123a of the negative electrode active material layer covering the exposed surface 103a of the base material 103 is thin. Specifically, the thickness T3 of the flat portion 123a is much smaller than the height H3 of the negative electrode current collector layer 113. In this example, since the volume of the negative electrode active material is small, the capacity is smaller than that in the example of FIG. 4B. However, since the negative electrode active material layer is thin, the internal resistance can be significantly reduced. The structures shown in FIGS. 4B and 4C can be formed as follows, for example.

  FIG. 5 is a diagram showing a first modification of the battery electrode manufacturing method of FIG. In order to obtain the structure shown in FIG. 4B or FIG. 4C, step S102 in the flowchart of FIG. 1 may be executed in two stages of sub-steps S102a and S102b shown in FIG. In sub-step S102a, the negative electrode active material coating solution is poured and applied between the line-shaped patterns of the negative electrode current collector layer 11 formed on the base material 10 in step S101. On the other hand, in sub-step S102b, the negative electrode active material coating solution is applied so as to overlap the line-shaped pattern of the negative electrode current collector layer 11 and cover the top portion thereof.

  More specifically, as shown in FIG. 5B, the coating liquid fills the space between the negative electrode current collector layers 112 to the same level as the height H2 of the negative electrode current collector layer 112 on the substrate 102. 4 is applied (substep S102a), and then the coating liquid is applied so as to cover the top of the negative electrode current collector layer 112 (substep S102b), whereby the structure shown in FIG. 4B can be obtained. On the other hand, as shown in FIG. 5C, a coating solution is applied thinly between the negative electrode current collector layers 113 (substep S102a), and then the coating solution is applied so as to cover the top of the negative electrode current collector layer 113. If applied (substep S102b), the structure shown in FIG. 4C can be obtained.

  In the example shown in FIG. 4D, the base material 104 has a structure in which the thin film 104b made of the negative electrode active material is formed on the upper surface of the copper foil 104a (the surface on the side where the negative electrode current collector layer 114 is formed). doing. Then, the negative electrode current collector layer 114 and the negative electrode active material layer 124 are sequentially formed on the base material 104 having such a structure, as in FIG. As will be described below, the copper foil 104a and the negative electrode current collector layer 114 are electrically connected, and these function integrally as a negative electrode current collector. In this structure example, since the contact area between the negative electrode current collector and the negative electrode active material is large, a low-resistance electrode can be obtained.

  FIG. 6 is a diagram showing an example of a structure for conducting the copper foil and the negative electrode current collector. More specifically, FIG. 6A is a perspective view showing the structure of the negative electrode base material 104 shown in FIG. 4D, and FIG. 6B is a cross-sectional view taken along the line A-A ′. The base material 104 has a structure in which the negative electrode active material 104b is applied to the surface of the copper foil 104a.

  Here, as shown in FIG. 6A, the negative electrode active material 104b is not applied to the entire surface of the copper foil 104a, but a part of the surface of the copper foil 104a is exposed at the downstream end portion in the Y direction. ing. The negative electrode current collector layer 114 formed by applying the conductive paste extends to the surface of the copper foil 104a thus exposed. For this reason, as shown in FIG.6 (b), the copper foil 104a which comprises the base material 104, and the negative electrode collector 114 by application | coating are partially contacting, and, thereby, conduction | electrical_connection between both is ensured. . Therefore, the copper foil 104a and the negative electrode current collector layer 114 are electrically integrated to function as a negative electrode current collector. On the other hand, since the negative electrode active material layer 104b of the base material 104 and the negative electrode active material layer 124 (FIG. 4D) applied on the current collector function integrally as a negative electrode active material layer, the surface area thereof is Greatly increased.

  FIG. 7 is a view showing a second modification of the battery electrode manufacturing method of FIG. In order to obtain the structure shown in FIG. 4D, step S101 in the flowchart of FIG. 1 may be executed in two stages, sub-steps S101a and S101b shown in FIG. In sub-step S101a, first, a copper foil 104a that is a part of the base material 104 and functions as a negative electrode current collector is prepared. In sub-step S101b, the negative electrode active material coating liquid is applied while leaving a part of the surface of the copper foil 104a to form the negative electrode active material layer 104b (FIG. 7B). And these are integrally regarded as the base material 104, and the process after step S102, that is, the current collector layer and the active material layer are laminated.

  In the example shown in FIG. 4E, the base material 105 is an insulator, and the negative electrode current collector layer 115 and the negative electrode active material layer 125 are formed on the upper surface 105a thereof. Even such a structure functions as an electrode for the negative electrode of the battery. And since the electrode for a battery can be formed not only what uses a conductor as a base material like the said example but also uses an insulator as the base material 105, according to this manufacturing method, operation | movement as a battery is inhibited. It is possible to form battery electrodes on virtually any substrate except those that do.

  In the negative electrode current collector layer 115 formed in a line-and-space structure on the surface of the base material 105 that is an insulator, the lines are electrically isolated from each other. In order to facilitate the exchange of electric charges with the outside by making them conductive with each other, for example, the following structure may be considered.

  FIG. 8 is a diagram illustrating an example of a structure for conducting current collectors. In this example, the negative electrode current collector layer 115 having a line-and-space structure composed of line patterns spaced apart from each other is electrically integrated by a line 115a formed by a coating solution applied so as to cross each line. Yes. By doing so, conduction between the line-shaped patterns is ensured, and these integrally function as a negative electrode current collector. Moreover, you may affix conductors, such as a copper ribbon, so that it may cross | intersect each linear pattern.

  Various structures other than those exemplified here can be considered as battery electrodes. For example, using a substrate in which a conductive layer functioning as a current collector is formed on the surface of the insulator by attaching a copper foil to the surface of the insulator such as a resin sheet or applying a conductive paste. it can. In such a structure, the conductive layer built in the base material and the current collector layer formed by the conductive paste applied thereto function as an integrated current collector.

  Further, the base material does not need to be an independent sheet, and for example, a battery electrode can be formed on the surface of a case of an electronic device as a base material. Such an example will be described later.

  As described above, in the battery electrode manufacturing method according to the present invention, various battery electrodes having excellent characteristics can be formed. Next, a battery manufacturing method using the battery electrode manufactured as described above will be described. The process flow from the production of the battery electrode to the completion of the battery can be continuously performed as a series.

  FIG. 9 is a flowchart showing an embodiment of the battery manufacturing method according to the present invention. FIG. 10 is a view showing an example of a battery manufactured by the manufacturing method of FIG. More specifically, FIG. 10 (a) is a schematic perspective view of a lithium ion secondary battery module as an embodiment of the battery according to the present invention, and FIG. 10 (b) is a diagram showing a sectional structure thereof. Hereinafter, a case where a battery is manufactured using the electrode for a negative electrode whose structure is illustrated in FIG. 4A will be described, but the manufacturing procedure is basically the same even when an electrode having another structure is used. .

  This lithium ion secondary battery module 1 has a structure in which an electrolyte layer 13, a positive electrode current collector layer 14, and a positive electrode current collector 15 are further laminated on the negative electrode 100 manufactured as described above. In order to obtain such a structure, first, the negative electrode 100 (base material 101, negative electrode current collector 111, negative electrode active material 121) is formed by the above method (step S201). Next, the electrolyte layer 13 is formed on the surface of the negative electrode 100 thus formed on the side where the negative electrode current collector layer 111 and the negative electrode active material layer 121 are formed so as to cover the surface of the negative electrode active material layer 121. Form. Specifically, an electrolyte layer 13 made of a solid electrolyte is obtained by applying a coating solution containing a solid electrolyte material by an appropriate coating method, for example, spin coating, and drying and curing the coating solution.

Since the coating technique by the spin coat method is known, the description of the apparatus configuration is omitted. As the electrolyte coating solution, a polymer electrolyte material, for example, a resin such as polyethylene oxide or polystyrene, a mixture of, for example, LiPF ₆ (lithium hexafluorophosphate) as a supporting salt and a solvent such as diethylene carbonate, etc. Can do.

  In the spin coating method, the negative electrode 100 held substantially horizontally is rotated around the vertical axis at a predetermined rotation speed, and a coating solution containing a polymer electrolyte material is supplied from a nozzle provided at an upper position on the rotation axis. Discharged. The coating liquid dropped on the negative electrode 100 spreads around by centrifugal force, and excess liquid is shaken off from the end. By doing so, the upper surface of the negative electrode 100 is covered with a thin and uniform coating solution. In the spin coating method, the film thickness can be controlled by the viscosity and the rotation speed of the coating solution, and the thickness along the unevenness is also applied to the object having an uneven structure on the surface, such as the negative electrode 100 of the present case. There is also a sufficient track record in forming a uniform thin film.

  The thickness of the solid electrolyte layer 13 is arbitrary, but it is necessary that the positive and negative active material layers be reliably separated and that the internal resistance be less than an allowable value. For example, it can be set to 20 μm to 50 μm. From the viewpoint that the significance of the unevenness of the negative electrode active material layer 121 provided to increase the surface area is not destroyed, the thickness of the solid electrolyte layer 13 (the symbol t13 in FIG. 10B) is the negative electrode active material layer. It is desirable that the height difference of the unevenness 121 is smaller than the reference numeral t12 in FIG.

The laminated body formed by laminating the copper foil 101, the negative electrode current collector layer 111, the negative electrode active material layer 121, and the solid electrolyte layer 13 thus formed is subjected to a positive electrode active by an appropriate method, for example, a known knife coating method. The positive electrode active material coating liquid containing the material is applied to form the positive electrode active material layer 14 (step S203). Examples of the coating liquid containing the positive electrode active material include LiCoO ₂ (LCO) as the positive electrode active material, acetylene black as the conductive auxiliary agent, SBR as the binder, carboxymethyl cellulose (CMC) as the dispersing agent, and the like. An aqueous LCO material in which pure water or the like as a solvent is mixed can be used. The positive electrode active material, other LCO described above, LiNiO ₂ or _{LiFePO 4, LiMnPO 4, LiMn 2} O 4, also _{LiMeO 2 (Me = M x M} y M z; Me, M is a transition metal, x + y + z = 1 ), For example, LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , LiNi _0.8 Co _0.15 Al _0.05 O _{2 and the} like can be used. In addition to the knife coating method exemplified below, as a coating method, a known coating method capable of forming a flat film on a flat surface, such as a bar coating method or a spin coating method, may be appropriately employed. Can do.

  Since the coating technique by a knife coat method is well-known, the description about the apparatus structure for it is abbreviate | omitted. In the knife coating method, a coating liquid containing a positive electrode active material is discharged onto an object to be coated, and a blade placed close to the upper surface of the object to be coated moves horizontally on the upper surface of the object to be coated while its lower end is in contact with the coating liquid. To do. Thereby, the upper surface of the coating liquid is leveled.

  In this way, by applying the coating liquid containing the positive electrode active material while leveling with the blade, the lower surface has irregularities along the irregularities of the solid electrolyte layer 13, while the upper surface has a substantially flat positive electrode active material layer 14. A copper foil 101, a negative electrode current collector 111, a negative electrode active material layer 121, and a solid electrolytic layer 13 are formed on a laminated body. The thickness of the positive electrode active material layer 14 is suitably 20 μm to 100 μm.

  And the metal foil used as the positive electrode collector 15, for example, aluminum foil, is laminated | stacked on the upper surface of the positive electrode active material layer 14 formed in this way (step S204). At this time, it is desirable to overlap the positive electrode current collector 15 on the upper surface of the positive electrode active material layer 14 formed in the previous step S203 before it is cured. By doing so, the positive electrode active material layer 14 and the positive electrode current collector 15 can be bonded to each other and bonded together. Moreover, since the upper surface of the positive electrode active material layer 14 is leveled, it is easy to stack the positive electrode current collector 15 without any gap. Thus, the lithium ion secondary battery module 1 is formed. The lithium ion secondary battery module 1 is appropriately provided with a tab electrode, or a plurality of modules are stacked to constitute a lithium ion battery.

  The lithium ion secondary battery module 1 manufactured in this way is a thin high-performance one in which positive and negative active material layers face each other over a wide area through a thin solid electrolyte layer, and each functional layer Is mainly formed by coating, so that it can be manufactured with few steps and excellent productivity.

  When the electrolyte layer 13 is made of a solid electrolyte, the battery thus formed is an all-solid battery that does not contain an organic solvent, is easy to handle, and has a small size and excellent performance. Such batteries include machines such as electric vehicles, electric assist bicycles, electric tools, robots, personal computers, mobile phones and portable music players, mobile devices such as digital cameras and video cameras, smart IC cards, and game machines. It can be used for various electronic devices such as portable measuring devices, communication devices and toys.

  Hereinafter, examples of devices equipped with the battery according to the present invention will be described. These are examples of a part of devices to which the battery according to the present embodiment can be applied. The scope of application is not limited to these.

  FIG. 11 is a diagram schematically showing a vehicle, specifically an electric vehicle, as an example of a device equipped with a battery according to the present invention. The electric vehicle 70 includes a wheel 71, a motor 72 that drives the wheel 71, and a battery 73 that supplies electric power to the motor 72. As this battery 73, the structure which connected many above-mentioned lithium ion secondary battery modules 1 in series and parallel is employable. The battery 73 configured as described above is suitable as a power source for driving a vehicle such as the electric vehicle 70 because it has a high current supply capability and can be charged in a short time.

  In this field, it is required to extend the cruising distance and shorten the charging time, and the battery according to the present invention can meet these requirements. That is, according to the present invention, a thin and high-power battery module can be configured, and since the output per weight is large, a long cruising distance can be obtained. In addition, since the contact area between the current collector and the active material layer and the facing area between the positive and negative active material layers through the electrolyte layer can be made large, the charge / discharge characteristics are good, and the charge / discharge in a short time Is possible.

  FIG. 12 is a view showing an example of an electronic apparatus to which the battery according to the present invention is applied. More specifically, FIG. 12 is an external perspective view of a battery built-in type IC card as an example of an electronic device. This IC card 80 has a structure in which a battery 800 according to the present invention, a circuit block 82 including an IC, and a loop antenna 83 are formed in a thin plastic card body 81.

  The antenna 83 transmits / receives radio waves to / from an external device and performs data communication between the external device and the circuit block 82. The circuit block 82 performs predetermined data processing on data received from an external device, stores the data, and sends data to be transmitted to the antenna 83. The battery 800 functions as a power source for the circuit block 82 to operate.

  The battery 800 has the same configuration as the above-described lithium ion secondary battery module 1 (FIG. 10), and can be housed inside the card body 81 or can be built on the surface of the card body 81. Is possible. That is, by using the card body 81 as a base material, a negative electrode current collector layer is formed on the surface thereof by coating, and functional layers such as an active material layer and an electrolyte layer are sequentially laminated on the card body 81, thereby A battery 800 can be formed on the surface. In such a utilization form, it is desirable to further provide an insulating protective layer that covers the battery surface after the battery is formed.

  As described above, in this embodiment, the negative electrode 100 corresponds to the “battery electrode” of the present invention, and the base materials 10, 101, 102, 103, 104, and 105 constituting this are the present invention. The negative electrode current collectors 11, 111, 112, 113, 114, and 115 correspond to the “current collector layer” and the “first current collector layer” of the present invention, respectively. In the flowchart of FIG. 1, steps S102 and S103 correspond to the “current collector layer forming step” and the “active material layer forming step” of the present invention, respectively.

  In this embodiment, the negative electrode active material layers 12, 121, 122, 123, 124, and 125 function as the “active material layer” and the “first active material layer” of the present invention. The solid electrolyte layer 13, the positive electrode active material layer 14, and the positive electrode current collector layer 15 function as the “electrolyte layer”, “second active material layer”, and “second current collector layer” of the present invention, respectively. . Further, steps S202 and S203 in the flowchart of FIG. 9 correspond to the “electrolyte layer forming step” and the “second active material layer forming step” of the present invention, respectively.

  In this embodiment, the nozzles 31 and 33 function as a “nozzle” and a “second nozzle” of the present invention, respectively. Further, in this embodiment, the electric vehicle 70 and the IC card 80 correspond to the “vehicle” and “electronic device” of the present invention, respectively, and the card body 81 and the circuit block 82 respectively correspond to the “casing” and the present invention. It corresponds to the “circuit part”.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, the coating method applied in each step is not limited to the above, and other coating methods may be applied as long as they meet the purpose of the step. For example, in the above-described embodiment, the spin coating method is applied to form the solid electrolyte layer 13, but any other method can be used as long as it can form a thin film that follows the unevenness of the surface to be coated. For example, a coating solution containing a polymer electrolyte may be applied by a spray coating method.

  Further, for example, in the above embodiment, the negative electrode current collector layer 11 has a line and space structure composed of a large number of parallel line patterns, but the coating pattern of the negative electrode current collector is not limited to this, Any pattern can be used as long as it has a concavo-convex structure on the surface to increase the surface area. Further, the line patterns may be connected to each other. Further, in this embodiment, a part of the surface of the base material 10 on which the negative electrode current collector layer 11 is formed is exposed, but the entire surface of the base material 10 is covered with the negative electrode current collector layer having irregularities. It may be a structure.

  Further, for example, in the above embodiment, the knife coating method is applied to form the positive electrode active material layer 14, but the lower surface in contact with the surface to be coated follows the unevenness, and the upper surface can be finished substantially flat. Any other application method may be used as long as it is possible. In order to achieve such an object, it is desirable that the viscosity of the coating solution is not so high. In other words, if the viscosity of the coating solution is appropriately selected, the lower surface may be uneven and the upper surface may be omitted by other coating methods. It is possible to finish it flat. For example, the coating liquid may be poured into the recesses of the unevenness of the application target surface by a nozzle scanning method.

  In the above embodiment, the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector are sequentially laminated on the base material. The positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector may be laminated in this order. Further, the present invention may be applied to the production of a positive electrode having a positive electrode current collector layer and a positive electrode active material layer, and the positive electrode and the negative electrode individually produced by the production method of the present invention. You may make it comprise a battery combining the electrode for an object.

  Further, the materials such as the current collector, active material, and electrolyte exemplified in the above embodiment are only examples, and are not limited thereto, and other materials used as a constituent material of the lithium ion battery are used. Even in the case of manufacturing a lithium ion battery, the manufacturing method of the present invention can be preferably applied. Further, the present invention is not limited to the lithium ion battery, and the present invention can be applied to the manufacture of all chemical batteries (all solid batteries) using other materials.

  The present invention is particularly suitable for constructing a battery having a small size, good electrochemical characteristics, and excellent productivity, and an electronic device including the battery.

10, 101, 102, 103, 104, 105 Base material 11, 111, 112, 113, 114, 115 Negative electrode current collector layer (current collector layer, first current collector layer)
12, 121, 122, 123, 124, 125 Negative electrode active material layer (active material layer, first active material layer)
13 Solid electrolyte layer (electrolyte layer)
14 Positive electrode active material layer (second active material layer)
15 Positive current collector layer (second current collector layer)
31 nozzles (nozzles)
33 nozzles (second nozzle)
70 Electric car (vehicle)
80 IC card (electronic equipment)
81 Card body (housing)
82 Circuit block (circuit part)
100 Negative electrode (battery electrode)
S102 Current collector layer forming step S103 Active material layer forming step S202 Electrolyte layer forming step S203 Second active material layer forming step

Claims (13)

A current collector layer forming step of applying a coating liquid containing a conductive material to the surface of the base material, and forming a current collector layer having irregularities on the surface opposite to the surface in contact with the base material;
An active material layer forming step of forming an active material layer having unevenness following the unevenness of the current collector layer surface by applying a coating liquid containing an active material on the surface of the current collector layer ;
In the current collector layer forming step, a coating liquid containing the conductive material is ejected linearly from a nozzle that moves relative to the surface of the base material to form the current collector composed of a plurality of linear patterns parallel to each other. A method for manufacturing an electrode for a battery, comprising forming an electric body layer . In the active material layer forming step, a coating liquid containing the active material is linearly discharged from a second nozzle that moves relative to the surface of the base material along the linear pattern of the current collector layer. The method for manufacturing a battery electrode according to claim 1 , wherein the active material layer covering the surface of the linear pattern is formed. In the active material layer forming step, a surface of the linear pattern of the current collector layer, in claim 1 to form the active material layer and a surface together covering of the substrate exposed between the linear pattern The manufacturing method of the battery electrode of description. In the active material layer forming step, a coating solution containing the active material material is poured onto the surface of the base material exposed between the linear patterns of the current collector layer, and further along the linear pattern, the base material A coating liquid containing the active material is linearly discharged from a second nozzle that moves relative to the surface of the substrate to form the active material layer covering the surface of the substrate and the surface of the linear pattern. Item 4. A method for producing a battery electrode according to Item 3 . The method for manufacturing a battery electrode according to claim 3 or 4 , wherein a thickness of the active material layer covering a surface of the base material is made smaller than a height of the linear pattern of the current collector layer. The method for producing a battery electrode according to any one of claims 1 to 5 , wherein a surface of the base material on which the current collector layer is formed has conductivity. The base material has a structure in which an active material film having the same polarity as the active material constituting the active material layer is formed on the surface of a current collector ,
In the current collector layer forming step, a coating liquid containing the conductive material is applied to the surface of the base material on which the active material film is formed, and is electrically connected to the current collector of the base material. method for producing a battery electrode according to any one of claims 1 to 5 forming the collector layer. The surface of the active material layer side of the claims 1 to 7 cell electrode produced by the production method according to any one of the laminated electrolyte layer, the second active material layer and the second current collector layer in this order A method for manufacturing a battery. An electrolyte layer forming step of applying a coating liquid containing an electrolyte material to the active material layer to form the electrolyte layer having irregularities following the irregularities of the surface of the active material layer;
A coating solution containing a second active material is applied to the electrolyte layer, and the surface in contact with the electrolyte layer has irregularities following the irregularities on the surface of the electrolyte layer, while the opposite surface is substantially flat. The battery manufacturing method according to claim 8 , further comprising a second active material layer forming step of forming an active material layer. A substrate;
A first current collector layer having irregularities on the surface opposite to the surface in contact with the substrate;
A first active material layer having irregularities following the irregularities on the surface of the current collector layer;
An electrolyte layer having irregularities following the irregularities on the surface of the first active material layer;
A second active material layer in which the surface in contact with the electrolyte layer has irregularities imitating the irregularities on the surface of the electrolyte layer, and the opposite surface is substantially flat;
Battery and second current collector layers have a structure formed by laminating in this order, characterized in that it is manufactured by the manufacturing method of battery according to claim 8 or 9. The battery according to claim 10 , wherein the first current collector layer includes a plurality of parallel patterns extending in a predetermined direction. Vehicle, characterized in mounting a battery produced by the production method according to claim 8 or 9. A circuit section;
A housing for holding the circuit unit;
The manufactured by the manufacturing method according to claim 8 or 9 a housing as the base material, electronic device, comprising a battery for supplying power to the circuit portion.

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