JP2012064487A - Method for manufacturing battery, battery, vehicle, and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a battery with excellent properties preventing each pair of adjacent functional layers from peeling, a battery manufactured by the method, and a device containing the battery.SOLUTION: A negative electrode collector layer (S101), a negative electrode active material layer (S102), a polymer electrolyte layer (S103), a positive electrode active material layer (S104), and a positive electrode collector layer (S105) are sequentially layered by coating a substrate with coating liquids each containing the material for each functional layer. Each pair of adjacent layers has excellent adhesion and hardly causes peeling between the layers because each layer is formed by coating. By coating with the active material layers in a pattern having a prescribed three-dimensional structure, the surface area becomes larger with respect to the amount of the active materials to improve battery properties.

Description

  The present invention relates to a battery manufacturing method in which an electrolyte layer is interposed between active material layers, a battery having the structure, and a device including the battery.

  For example, as a method of manufacturing a chemical battery such as a lithium ion 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 superposed via a separator, and an electrolytic solution is applied to the separator. A technique of impregnating with is known. In such a battery, the adhesion between different functional layers affects the performance of the battery. In particular, the adhesion between the metal foil serving as the current collector and the active material material supplied mainly in the form of small particles is not so good. There are problems such as a decrease in electrical conductivity between the layers and peeling between these layers.

  In order to cope with this problem, for example, Patent Document 1 discloses various binder materials for improving adhesion to the current collector foil by adding to the active material. In the technique described in Patent Document 2, an adhesion layer for preventing peeling is provided between the current collector layer and the active material layer. In the technique described in Patent Document 3, a paste containing an active material is applied to the surface of a metal foil current collector to form an active material layer, and then the metal foil and the active material are adhered to each other by roll pressing. I am letting.

JP 2010-009917 A (for example, paragraph 0012) Japanese Patent Laid-Open No. 2002-304997 (for example, FIG. 1) JP-A-11-185736 (for example, FIG. 10)

  In the techniques described in Patent Documents 1 and 2, a large amount of material that does not directly contribute to the function as a battery is mixed into the active material layer, so that a sufficient battery performance is not necessarily obtained. Absent. In addition, in this type of battery structure, there is a technical idea of improving the charge / discharge characteristics by increasing the surface area by providing a three-dimensional structure such as an uneven pattern on the surface of the active material layer. Since the three-dimensional structure is destroyed by the technique described in (1), it is difficult to apply to such a technical idea.

  As described above, in the conventional technique, a technique for manufacturing a battery having good characteristics while preventing separation between the current collector layer and the active material layer has not been established. .

  The present invention has been made in view of the above problems, and provides a technique for manufacturing a battery having good characteristics while preventing delamination between functional layers, and a battery manufactured thereby and various devices including the battery. The purpose is to provide.

  In order to achieve the above object, the battery manufacturing method according to the present invention applies the coating solution containing the material of the first current collector to the surface of the base material to form the first current collector layer. A body layer forming step, a first active material layer forming step of forming a first active material layer by applying a coating liquid containing a material of the first active material to the surface of the first current collector layer, and the first An electrolyte layer forming step of forming an electrolyte layer by applying a coating solution containing a solid electrolyte material on the surface of the active material layer, and applying a coating solution containing a material of the second active material on the surface of the electrolyte layer A second active material layer forming step of forming a second active material layer; and a second current collector layer formed by applying a coating solution containing a second current collector material to the surface of the second active material layer And 2 current collector layer forming step.

  In the invention thus configured, the first current collector layer, the first active material layer, the electrolyte layer, the second active material layer, and the second current collector layer, which are indispensable components for constituting a battery, are provided. Each functional layer is formed by coating. That is, each functional layer is formed by sequentially applying a coating liquid containing the material substance of the layer. For this reason, there is almost no problem of the adhesiveness which arises between the above-mentioned metal foil and the layer by application | coating, A battery with a favorable characteristic can be manufactured, preventing peeling between each functional layer.

  In addition, in the present invention, it is possible to manufacture batteries having various shapes and sizes by changing the coating pattern. If the coating pattern is changed by a program or the like, various shapes can be obtained. This battery can be manufactured with the same device configuration. For this reason, the battery which responds to various needs can be manufactured at low cost.

  Here, for example, in the first active material layer forming step, a line-shaped first active material layer is formed by applying a coating liquid containing the material of the first active material in a line shape on the surface of the first current collector layer. You may make it do. If it does in this way, the 1st active material layer which gave the uneven | corrugated shape on the surface can be formed, the surface area with respect to the usage-amount of 1st active material is increased, and the charge / discharge characteristic as a battery is improved. Can do. In this case, since the contact area of the first active material layer with respect to the first current collector layer becomes small, the problem of peeling as described above can be particularly noticeable. However, in this invention, since the first current collector layer is also formed by coating, the adhesion between the first current collector layer and the first active material layer is good, and such a problem does not occur.

  In this case, for example, a coating liquid containing the material of the first active material may be discharged from a nozzle that moves relative to the surface of the first current collector layer. According to such a so-called nozzle scan type coating method, a technique for forming a fine pattern by coating has been established. By applying this technique, the first active material layer having a fine three-dimensional structure is formed. It is possible to form. Thereby, the surface area of a 1st active material layer can be enlarged, and battery performance can be improved.

  In addition, for example, in the electrolyte layer forming step, an electrolyte layer having a surface with unevenness following the surface unevenness of the first active material layer may be formed. If it does in this way, since the 2nd active material layer laminated | stacked after that on an electrolyte layer will oppose a 1st active material layer in a large area through an electrolyte layer, the performance as a battery, especially a charge / discharge characteristic Can be further improved.

  In the present invention, for example, in the first current collector layer forming step, a plurality of first current collector layers separated from each other may be formed on the surface of the base material. By sequentially forming each functional layer after the first active material layer for each of the plurality of first current collector layers thus formed, a plurality of batteries (unit cells) are simultaneously formed on the substrate surface. can do. These unit cells can be connected to each other or disconnected from each other on a substrate as necessary. In this sense, the present invention is a technique suitable for mass production of batteries.

  Further, a battery may be manufactured using the housing of the electronic device as a base material of the present invention. In this way, the battery can be directly built into the housing of the electronic device. For example, a battery can be incorporated by directly applying a coating solution onto a card-like or sheet-like substrate such as an IC card carrier, and the size and cost of the device can be reduced.

  By the way, the problem of peeling between the metal foil and the layer by coating as described above is particularly remarkable when the foil is laminated on the layer formed by coating later than when the coating liquid is coated on the surface of the foil. is there. In this sense, it is important to improve the adhesion between the two current collector layers, particularly in the process of laminating the second current collector layer on the second active material layer.

  Therefore, in another aspect of the battery manufacturing method according to the present invention, in order to achieve the above object, the electrolyte layer side of the laminate formed by laminating the first current collector layer, the first active material layer, and the electrolyte layer is provided. A second active material layer forming step of forming a second active material layer by applying a coating liquid containing a second active material on the surface; and a second current collector material on the surface of the second active material layer And a second current collector layer forming step of forming a second current collector layer by applying a coating solution containing

  In the invention thus configured, the second current collector layer is formed by coating on the surface of the second active material layer formed by coating. Therefore, compared with the case where the second current collector layer is formed by laminating the metal foil on the surface of the second active material layer, the separation between the second active material layer and the second current collector layer and the It is possible to greatly reduce the occurrence of problems caused by it.

  In order to achieve the above object, the battery according to the present invention has a structure in which a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector layer are laminated. The battery is manufactured by any one of the battery manufacturing methods described above. In the battery configured as described above, since peeling does not easily occur between the current collector layer and the active material layer, deterioration of characteristics due to peeling is prevented. In addition, since such a structure has durability against bending and winding, a small battery with high energy density can be configured.

  In addition, the vehicle according to the present invention is characterized in that the battery having the above-described structure is mounted in order to achieve the above object. Furthermore, in order to achieve the above object, an electronic apparatus according to the present invention includes a battery having the above structure and a circuit unit that operates using the battery as a power source. In these inventions, various vehicles or electronic devices equipped with small and high-performance batteries can be configured. In particular, in an electronic device having a housing that holds a circuit portion, when the battery is manufactured using the housing as a base material, the device can be reduced in size and cost.

  According to the present invention, since the active material layer and the current collector layer formed by coating are both laminated, there is no problem of peeling caused by poor adhesion between the metal foil current collector and the active material, It is possible to manufacture a battery with good characteristics while suppressing problems caused by peeling.

It is a figure which shows one Embodiment of the battery concerning this invention. It is a flowchart which shows the manufacturing method of the lithium ion secondary battery module in this embodiment. It is a figure which shows typically the mode of material application by the spray coat method. It is a figure which shows typically the mode of material application by a knife coat method. It is a figure which shows typically the mode of material application by the nozzle scan method. It is a figure which shows typically the mode of negative electrode active material layer formation by the nozzle scan method. It is a figure which shows typically the mode of material application | coating by a spin coat method. It is a figure which shows typically the mode of positive electrode active material application | coating by a knife coat method. 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 typically the electronic device as another example of the apparatus carrying the battery concerning this invention. It is a figure which shows the example which comprised the some battery module on the base material.

  FIG. 1 is a diagram showing an embodiment of a battery according to the present invention. More specifically, FIG. 1 (a) is a schematic perspective view of a lithium ion secondary battery module 1 as an embodiment of a battery according to the present invention, and FIG. 1 (b) is a diagram showing a sectional structure thereof. . The lithium ion secondary battery module 1 includes a negative electrode current collector layer 11, a negative electrode active material layer 12, a solid electrolyte layer 13, a positive electrode active material layer 14, and a positive electrode on the surface of a base material 10 such as a glass substrate or a resin sheet. It has a structure in which the current collector layers 15 are laminated in order. In this specification, the X, Y, and Z coordinate directions are defined as shown in FIG.

  As shown in FIG. 1B, the negative electrode current collector layer 11 is a uniform thin film formed on the base material 10, while the negative electrode active material layer 12 has a linear pattern 121 extending along the Y direction. Has a line and space structure in which a large number of are arranged at regular intervals in the X direction. The dimension of each line-shaped pattern 121 can be, for example, 20 μm to 200 μm in both width and height.

  On the other hand, the solid electrolyte layer 13 is a continuous thin film formed of a solid electrolyte, and follows (follows) the irregularities on the surface of the laminate in which the negative electrode active material layer 12 is formed on the negative electrode current collector 11 as described above. As shown in the figure, almost the entire top surface of the laminate is uniformly covered. 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, the thickness can be 20 μm to 50 μm. From the viewpoint that the significance of the unevenness of the negative electrode active material layer 12 provided to increase the surface area is not destroyed, the thickness t13 of the solid electrolyte layer 13 is larger than the height difference t12 of the unevenness of the negative electrode active material layer 12. Small is desirable.

  Moreover, the lower surface side of the positive electrode active material layer 14 has an uneven structure that follows the unevenness of the upper surface of the solid electrolyte layer 13, but the upper surface is substantially flat. The thickness of the positive electrode active material layer 14 can be set to, for example, 20 μm to 100 μm. And the positive electrode collector 15 is laminated | stacked on the upper surface of the positive electrode active material layer 14 formed in this substantially flat shape, and 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 form a lithium ion secondary battery.

Here, as a material constituting each layer, a known material as a constituent material of the lithium ion battery can be used. As the negative electrode current collector layer 11 and the positive electrode current collector layer 15, for example, copper or aluminum is used. Each can be used. Further, as the positive electrode active material, for example, a material mainly composed of LiCoO ₂ (LCO) can be used, and as the negative electrode active material, for example, a material mainly composed of Li ₄ Ti ₅ O ₁₂ (LTO) can be used. Moreover, as the solid electrolyte layer 13, for example, polyethylene oxide and polystyrene can be used. The material of each functional layer is not limited to these.

  The lithium ion secondary battery module 1 having such a structure is thin and easy to bend. Moreover, since the surface area with respect to the volume is made large as the three-dimensional structure which has the unevenness | corrugation which illustrated the negative electrode active material layer 12 in figure, the opposing area with the positive electrode active material layer 14 through the thin solid electrolyte layer 13 is enlarged. High efficiency and high output can be obtained. Thus, the lithium ion secondary battery having the above-described structure is small and can obtain high performance.

  Next, a method for manufacturing the above-described lithium ion secondary battery module 1 will be described. Conventionally, this type of module has been formed by laminating thin film materials corresponding to each functional layer. However, this manufacturing method has a limit in increasing the density of the module. In the manufacturing method described below, the lithium ion secondary battery module 1 having the above-described excellent structure can be manufactured with a small number of steps.

  FIG. 2 is a flowchart showing a method of manufacturing the lithium ion secondary battery module in this embodiment. In this embodiment, the lithium ion secondary battery module 1 is manufactured by sequentially forming each functional layer on the base material 10 by coating, and a known coating technique for forming each layer is applied. Therefore, only the concept of the coating method will be briefly described below, and a detailed description of the configuration of the coating apparatus will be omitted. In this manufacturing method, first, an appropriate flat plate material such as a glass substrate or a resin sheet to be the base material 10 is prepared, and a coating liquid containing a negative electrode current collector material is applied to the surface by, for example, a spray coating method (step S101). ), And the negative electrode current collector layer 11 is formed on the surface of the substrate 10.

  FIG. 3 is a diagram schematically showing a state of material application by the spray coating method. In the spray coating method, droplets 20p of a coating liquid (for example, conductive paste) including, for example, copper powder, which is a material of the negative electrode current collector 11, are ejected from a nozzle 20 disposed above the base material 10 that is an application target. The negative electrode current collector layer 11 having a substantially constant thickness is formed by uniformly adhering it to the surface of the substrate 10. The method for forming the negative electrode current collector layer is not limited to the spray coating method, and for example, as exemplified below, a coating method such as a knife coating method or a nozzle scanning method can also be used.

  FIG. 4 is a diagram schematically showing a state of material application by the knife coating method. A coating apparatus (knife coater) for coating a coating liquid by a knife coating method is configured to be movable in the X direction, and a discharge nozzle 21 that discharges the coating liquid and a coating liquid 21p discharged from the discharge nozzle 21 as a base material. And a moving mechanism 24 that horizontally moves a support block 23 that supports the blade 22 in the Y direction. When the discharge nozzle 21 moving in the X direction discharges the coating liquid 21p onto the base material 10, the blade 22 supported at a lower end portion with a predetermined gap from the surface of the base material 10 together with the support block 23 operates the moving mechanism 24. As a result of the horizontal movement in the Y direction, the coating liquid is leveled on the substrate 10, and a thin and uniform negative electrode current collector layer 11 is formed on the upper surface of the substrate 10. As the knife coater, for example, the one described in JP-A-07-289973 can be used.

  FIG. 5 is a diagram schematically showing a state of material application by the nozzle scanning method. In the application by the nozzle scanning method, the discharge nozzle 27 that continuously discharges the coating liquid containing the negative electrode current collector material is reciprocally scanned in the Y direction on the substrate 10, and is positioned little by little in the X direction for each scan. Will change. At this time, the feed pitch of the discharge nozzles 27 in the X direction is made substantially equal to the width of the coating liquid 27p discharged from the discharge nozzles 27. The discharge port diameter of the discharge nozzle 27 can be, for example, about 0.2 mm to 1 mm. This also makes it possible to form the negative electrode current collector layer 11 having a substantially constant thickness on almost the entire surface of the substrate 10.

  Next, a coating liquid containing a negative electrode active material is applied in a line shape by a nozzle scanning method to the laminate in which the negative electrode current collector layer 11 is formed on the surface of the base material 10 in this way, and the negative electrode active material layer 12 is formed (step S102). As described above, the negative electrode active material layer 12 is composed of a plurality of parallel patterns 121 formed on the surface of the substantially flat negative electrode current collector layer 11. As a coating method for forming such a line pattern, the nozzle scanning method is most suitable.

As the coating solution, for example, an organic LTO material (organic / inorganic composite material) containing the negative electrode active material described above 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. 6 is a diagram schematically showing how the negative electrode active material layer is formed by the nozzle scanning method. More specifically, FIG. 6A is a view of the application state of the coating liquid containing the negative electrode active material by the nozzle scanning method as viewed from the X direction, and FIG. 6B and FIG. 6C are the same states. It is the figure seen from the Y direction and diagonally upward.

  In the nozzle scanning method in this case, a syringe pump 31 in which a plurality of discharge nozzles 311 having discharge ports 311 for discharging the organic LTO material as a coating liquid is disposed along the X direction is disposed above the object to be coated. Deploy. The object to be coated in this case is a laminate 100 in which the negative electrode current collector layer 11 is laminated on the base material 10, and the application target surface is the surface on the side where the negative electrode current collector layer 11 is formed. The discharge nozzle 311 is disposed above the laminated body 100, and the discharge nozzle 311 is discharged at a constant speed in the arrow direction Dn2 (Y direction) relative to the laminated body 100 while discharging a fixed amount of the coating liquid 31p from the discharge port 312. Use to scan.

  By doing so, the coating liquid 31p is applied in a line shape along the Y direction on the laminate 100. By providing a plurality of discharge nozzles 311 in the syringe pump 31, a plurality of stripes can be formed by a single scanning movement, and by repeating the scanning movement as necessary, it is applied to the entire surface of the laminate 100 in a line shape. A liquid can be applied. By drying and curing this, a line-shaped pattern 121 made of a negative electrode active material is formed on the upper surface of the laminate 100. 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.

  At this time, when the negative electrode active material layer 12 is partially raised with respect to the surface of the substantially flat negative electrode current collector layer 11, the coating liquid is simply applied so that the upper surface is flat. In comparison, since the surface area relative to the amount of active material used can be increased, the facing area with the positive electrode active material to be formed later can be increased to obtain a high output.

The description of the flowchart of FIG. 2 will be continued. An electrolyte coating solution containing an electrolyte material is applied to the upper surface of the laminate formed by laminating the anode active material layer 12 on the anode current collector layer 11 thus formed by an appropriate coating method, for example, a spin coating method ( Step S103). As the electrolyte coating solution, a mixture of the above-described polymer electrolyte material, for example, a resin such as polyethylene oxide or polystyrene, for example, LiPF ₆ (lithium hexafluorophosphate) as a supporting salt, and, for example, diethylene carbonate as a solvent, etc. Can be used.

  FIG. 7 is a diagram schematically showing a state of material application by spin coating. A laminate 101 in which a negative electrode active material layer 12 composed of a line pattern 121 is laminated on a negative electrode current collector layer 11 on a substrate 10 is freely rotatable around a rotation axis in the vertical direction (Z direction) in a predetermined rotation direction Dr. Is mounted on the rotary stage 42 substantially horizontally. Then, the rotation stage 42 rotates at a predetermined rotation speed, and the coating liquid 41p containing the polymer electrolyte material is discharged toward the laminated body 101 from the nozzle 41 provided at the upper position on the rotation axis of the rotation stage 42. . The coating liquid dropped on the laminate 101 spreads around by centrifugal force, and excess liquid is shaken off from the end of the laminate 101. By doing so, the upper surface of the laminate 101 is covered with a thin and uniform coating solution. In the spin coating method, the film thickness can be controlled by the viscosity of the coating solution and the rotation speed of the rotary stage 42, and the unevenness is also applied to the object having a concavo-convex structure on the surface such as the laminate 101. There is also a sufficient track record in forming a thin film with a uniform thickness.

Returning to FIG. 2 again, the description of the flowchart will be continued. A positive electrode containing a positive electrode active material by an appropriate method, for example, the knife coating method described above, for the laminate formed by laminating the negative electrode current collector layer 11, the negative electrode active material layer 12, and the solid electrolyte layer 13 thus formed. The active material coating solution is applied to form the positive electrode active material layer 14 (step S104). Examples of the coating liquid containing the positive electrode active material include, for example, the above-described positive electrode active material, acetylene black as a conductive additive, SBR as a binder, carboxymethyl cellulose (CMC) as a dispersant, and pure water as a solvent. A water-based LCO material mixed with the above 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 here, 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, is appropriately employed as the coating method. Can do.

  FIG. 8 is a diagram schematically showing a state of applying the positive electrode active material by the knife coating method. The coating liquid 52p containing the positive electrode active material is discharged from a nozzle (not shown) onto the surface of the laminate 102 formed by laminating the base material 10, the negative electrode current collector layer 11, the negative electrode active material layer 12, and the solid electrolyte layer 13. The The blade 52 arranged close to the upper surface of the laminated body 102 moves in the arrow direction Dn3 on the upper surface of the laminated body with its lower end in contact with the coating solution. Thereby, the upper surface of the coating liquid 52p is leveled.

  In this way, by applying the coating liquid 52p containing the positive electrode active material to the laminate 102 while leveling with the blade 52, the lower surface has irregularities along the irregularities of the solid electrolyte layer 13, while the upper surface is substantially flat. An active material layer 14 is formed on a laminate 102 formed by laminating a base material 10, a negative electrode current collector 11, a negative electrode active material layer 12, and a solid electrolytic layer 13. The thickness of the positive electrode active material layer 14 is suitably 20 μm to 100 μm.

  Returning to FIG. 2, a coating liquid containing a metal powder, for example, aluminum powder, that becomes the positive electrode current collector 15 is applied to the upper surface of the positive electrode active material layer 14 thus formed by an appropriate application method, for example, a spray coating method ( Step S105). As with the negative electrode current collector layer 11, coating may be performed by a knife coating method or a nozzle scanning method. Thereby, a substantially uniform positive electrode current collector layer 15 is formed on the upper surface of the positive electrode active material layer 14.

  As described above, in this embodiment, the functional layers constituting the battery, that is, the negative electrode current collector layer 11, the negative electrode active material layer 12, the solid electrolyte layer 13, the positive electrode active material layer 14, and the like are formed on the surface of the substrate 10. When the positive electrode current collector layer 15 is laminated, each of these layers is formed by coating. More specifically, the lithium ion secondary battery module 1 having the structure shown in FIG. 1 is formed by applying a coating solution containing the material of each functional layer by a coating method suitable for the shape of the functional layer. ing. By forming each functional layer by coating in this way, the degree of adhesion between the respective layers is increased as compared with, for example, a case where a metal foil is used as the current collector layer. For this reason, the movement of charges and ions between the respective layers is smooth, which contributes to the improvement of charge / discharge characteristics as a battery. Further, even when the module is bent, for example, peeling between the layers is difficult to occur, and deterioration of characteristics due to peeling can be suppressed, and excellent characteristics can be stably obtained.

  Further, by forming the negative electrode active material layer 12 having a line and space structure by a nozzle scanning method, the negative electrode active material layer 12 having a large surface area relative to the volume of the material can be formed. According to the coating using the nozzle scanning method, for example, a much larger amount of coating liquid can be continuously discharged than in the known ink jet method, so that the negative electrode active material layer 12 having a large uneven pattern with a large difference in height is formed. It can be formed in a short time.

  Further, the exposed surface of the negative electrode current collector layer 11 that is not covered with the negative electrode active material layer 12 and the surface of the negative electrode active material layer 12 are covered with a thin solid electrolyte layer 13 formed by coating, and the positive electrode active material is further formed on the surface. By forming the material layer 14 by coating, it is possible to realize a structure in which the negative electrode active material layer 12 and the positive electrode active material layer 14 face each other over a wide area with the thin electrolyte layer 13 interposed therebetween. Thereby, since the movement of ions and charges through the electrolyte layer 13 is performed at a high speed, good charge / discharge characteristics can be obtained even when a solid electrolyte having a low ion conductivity is used.

  For these reasons, the lithium ion secondary battery module 1 thus manufactured is thin and has good electrochemical characteristics. And the battery comprised using this is an all-solid-state battery which does not contain an organic solvent, and while being easy to handle, it is small and has 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. 9 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.

  FIG. 10 is a diagram schematically showing an electronic device, specifically, an IC card (smart card) as another example of a device equipped with a battery according to the present invention. More specifically, FIG. 10 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. 1), 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.

  According to such a configuration, the communicable distance with the external device can be extended and more complicated processing can be performed as compared with a general IC card that does not have a power supply. Become. Since the battery 800 according to the present invention is small and thin and has a large capacity, it can be suitably applied to such a card-type device.

  In addition, for example, the battery according to the present invention can be suitably applied when various sensors such as a temperature sensor and a pressure sensor and the battery are integrated into a module. In this case, if the battery according to the present invention is used not only for operating the sensor but also for example as a power source of an amplifier that amplifies the sensor output, a sensor module that is small and has high output and is resistant to noise can be configured. It becomes possible.

  In addition, since each functional layer is formed by coating in the battery manufactured as described above, the coating pattern and coating area of each functional layer can be relatively freely selected by appropriately selecting a coating method. It is possible to set. This means that the battery can be formed in various shapes. For example, it is possible to manufacture battery modules having various shapes according to the size and shape of the housing in which the battery is accommodated. It is. Moreover, when manufacturing a battery module industrially, the following application is also considered, for example.

  FIG. 11 is a diagram illustrating an example in which a plurality of battery modules are configured on a base material. As shown in FIG. 11A, a plurality of negative electrode current collector layers 11a are formed on a single substrate 10a by using, for example, a nozzle scanning method, and other functional layers are sequentially stacked in the same pattern. By doing so, as shown in FIG. 11 (b), it is possible to simultaneously form a plurality of battery modules 1a each operating as a battery (unit cell) on a single substrate 10a. And it becomes possible to manufacture many battery modules 1a in a short time by cutting the base material 10a as needed and separating each battery module 1a.

  Further, if the coating pattern of the negative electrode and / or the positive electrode current collector layer is different from the other layers, and the adjacent modules are electrically connected via the current collector on the substrate 10a, It is also possible to manufacture the battery modules 1a in a state where the battery modules 1a are connected in series or in parallel on the substrate 10a.

  When a metal foil is used as a current collector, it is difficult to form a current collector layer having such a complicated pattern, and each functional layer is formed by coating also in terms of freedom of shape and dimensions. There are advantages.

  By the way, the problem of peeling between the metal foil current collector and the active material described above is that metal is applied to the active material layer formed by coating, rather than the case where the active material layer is formed by applying a coating liquid to the metal foil. This is particularly serious when laminating foils. For example, consider the case where the positive and negative current collector layers of a lithium ion secondary battery module as shown in FIG. In this case, for example, a copper foil can be used as the negative electrode current collector, and an aluminum foil can be used as the positive electrode current collector.

  Here, when the negative electrode active material is applied to the surface of the copper foil as the negative electrode current collector, the coating liquid discharged from the nozzle directly adheres to the copper foil, so that the negative electrode current collector and the negative electrode active material Adhesion is relatively good. On the other hand, when the aluminum foil as the positive electrode current collector is attached to the positive electrode current collector layer in which the coating liquid is applied to the surface of the solid electrolyte layer, the surface of the coating liquid starts to dry, There is a high possibility that the adhesion between the current collector and the active material is inferior due to bubbles entering. Thus, when the current collector foil is laminated on the active material layer formed by coating, the problem of peeling between them is particularly serious.

  Therefore, from the viewpoint of preventing delamination between layers, when the current collector layer is laminated on the formed active material layer, it can be said that it is essential to form the current collector by coating. On the other hand, when the active material layer is laminated on the current collector layer, it is preferable that the current collector is formed by coating, but this is not essential. In this sense, the negative electrode current collector 11 in the above embodiment may be a flat plate such as a metal foil. However, it is desirable that the positive electrode current collector 15 is applied by coating in order to ensure adhesion with the positive electrode active material layer 14.

  In the above description, it is assumed that the negative electrode current collector layer 11 is formed first, but a battery may be formed by laminating sequentially from the positive electrode current collector layer in the reverse order to the above. In some cases, a foil or flat plate material can be used as the positive electrode current collector, while the negative electrode current collector is preferably formed by coating.

  The technical idea of forming the current collector by coating is also described in, for example, Japanese Patent Application Laid-Open No. 2009-181874. However, the technology described in the publication discloses that a positive electrode active material layer and a negative electrode active material layer formed into a thin plate by firing are each coated with a slurry containing a current collector material to form a positive electrode and a negative electrode, respectively. A thin plate-like solid electrolyte is sandwiched and bonded together. Therefore, the problem of the adhesion between the active material formed by firing and the current collector still remains. In order to alleviate this problem, this known technique includes a viscoelastic material in the active material layer.

  Compared to such a technique, the manufacturing method of the present embodiment employs a process of forming and laminating both the active material and the current collector by coating, so the active material and the current collector Is much better and has less risk of delamination between layers. In addition, since it is not necessary to add a material that does not contribute to performance, the battery characteristics are also good. In particular, if the active material layer on one electrode has a line-and-space structure, the surface area relative to the amount of active material used can be increased, and the charge / discharge characteristics can be further improved.

  As described above, in this embodiment, the negative electrode current collector corresponds to the “first current collector” of the present invention, and the negative electrode current collector 11 corresponds to the “first current collector layer” of the present invention. Is functioning. 2 corresponds to the “first current collector layer forming step” of the present invention. Further, the negative electrode active material corresponds to the “first active material” of the present invention, the negative electrode active material layer 12 functions as the “first active material layer”, and step S102 in FIG. This corresponds to the “first active material layer forming step”. The discharge nozzle 311 provided in the syringe pump 31 functions as the “nozzle” of the present invention.

  In this embodiment, step S103 in FIG. 2 corresponds to the “electrolyte layer forming step” of the present invention. Further, the positive electrode active material corresponds to the “second active material” of the present invention, the positive electrode active material layer 14 functions as the “second active material layer”, and step S104 in FIG. This corresponds to the “second active material layer forming step”. Further, the positive electrode current collector corresponds to the “second current collector” of the present invention, and the positive electrode current collector 15 functions as the “second current collector layer” of the present invention. Step S105 in FIG. 2 corresponds to the “second current collector layer forming step” of the present invention.

  10 is an example of the “electronic device” of the present invention, and the card body 81 functions as the “casing” of the present invention, while the circuit block 82 functions as the “circuit portion” of the present invention. is doing.

  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, in the above embodiment, the negative electrode active material layer 12 has a line and space structure composed of a large number of line-shaped patterns 121, but the coating pattern of the negative electrode active material layer is not limited to such a shape and is arbitrary. However, from the viewpoint of increasing the surface area, a layer having a certain three-dimensional structure is preferable. Alternatively, or in addition to this, the positive electrode active material layer may have such a three-dimensional structure.

  In the above embodiment, 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 negative electrode current collector. On the contrary, on 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. Moreover, the coating method of each layer is not limited to what was illustrated.

  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 can be applied not only to lithium ion batteries but also to all batteries using other materials.

  The present invention can be suitably applied to a technique for manufacturing a battery such as a lithium ion secondary battery, particularly an all-solid battery using a solid electrolyte.

10 base material 11 negative electrode current collector (first current collector, first current collector layer)
12 Negative electrode active material layer (first active material, first active material layer)
13 Electrolyte Layer 14 Positive Electrode Active Material Layer (Second Active Material, Second Active Material Layer)
15 Positive current collector (second current collector, second current collector layer)
80 IC card (electronic equipment)
81 Card body (housing)
82 Circuit block (circuit part)
311 Discharge nozzle (nozzle)
S101 First current collector layer forming step S102 First active material layer forming step S103 Electrolyte layer forming step S104 Second active material layer forming step S105 Second current collector layer forming step

Claims (11)

A first current collector layer forming step of forming a first current collector layer by applying a coating solution containing the material of the first current collector on the surface of the substrate;
A first active material layer forming step of forming a first active material layer by applying a coating liquid containing a first active material on the surface of the first current collector layer;
An electrolyte layer forming step of forming an electrolyte layer by applying a coating liquid containing a solid electrolyte material on the surface of the first active material layer;
A second active material layer forming step of forming a second active material layer by applying a coating liquid containing a second active material on the surface of the electrolyte layer;
And a second current collector layer forming step of forming a second current collector layer by applying a coating solution containing a second current collector material on the surface of the second active material layer. Manufacturing method.   In the first active material layer forming step, a line-shaped first active material layer is formed by applying a coating solution containing the material of the first active material in a line shape on the surface of the first current collector layer. The method for producing a battery according to claim 1.   The battery manufacturing according to claim 2, wherein in the first active material layer forming step, a coating liquid containing the material of the first active material is discharged from a nozzle that moves relative to the surface of the first current collector layer. Method.   4. The method for manufacturing a battery according to claim 2, wherein in the electrolyte layer forming step, the electrolyte layer is formed such that the surface has unevenness following the unevenness of the surface of the first active material layer. 5.   5. The battery manufacturing method according to claim 1, wherein, in the first current collector layer forming step, a plurality of the first current collector layers spaced apart from each other are formed on a surface of the base material.   The method for producing a battery according to claim 1, wherein a casing of an electronic device is the base material. A coating liquid containing a material for the second active material is applied to the surface on the electrolyte layer side of the laminate formed by laminating the first current collector layer, the first active material layer, and the electrolyte layer. A second active material layer forming step to be formed;
And a second current collector layer forming step of forming a second current collector layer by applying a coating solution containing a second current collector material on the surface of the second active material layer. Manufacturing method.   The battery according to any one of claims 1 to 7, having a structure in which a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector layer are laminated. A battery manufactured by the manufacturing method of 1.   A vehicle comprising the battery according to claim 8. A battery according to claim 8;
An electronic device comprising: a circuit portion that operates using the battery as a power source.   The electronic device according to claim 10, further comprising: a housing that holds the circuit unit, wherein the battery is manufactured using the housing as the base material.

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