JP5845413B2 - Electronic device with thin battery - Google Patents

Description

  The present invention relates to a thin battery-equipped electronic device with improved durability against bending deformation.

  As electronic devices become smaller, thinner, and lighter, electronic devices that can be bent freely have been developed. Further, in recent years, flexible thin batteries that can be mounted on these thin electronic devices have also been developed, and the usage applications of the thin electronic devices are expanding.

  For example, a thin battery-equipped electronic device with a fresh and effective concept that attracts the interest of consumers, such as battery-operated printing advertisements, product packaging, and trading cards, has been developed (for example, see Patent Document 1).

  With regard to electronic devices equipped with thin batteries, in particular, in recent years, devices that operate while in contact with a living body are increasing. For example, a measurement circuit that measures biological information such as body temperature, blood pressure, pulse, and the like, and when biological information that indicates a health change is obtained by monitoring the measured biological information, a radio signal is sent to a hospital, fire department, Biological information that is configured with a wireless transmission circuit that transmits to other facilities in the form of a sheet and is attached to the user's clothes so that a user can be automatically notified by radio signal when a health change occurs. Transmitting devices have been developed. In addition, a biological sticking type device that supplies a drug or the like through a living body skin by applying a potential has been developed (see, for example, Patent Document 2).

  Against this background, a large number of electronic devices equipped with thin batteries have been developed together with thin batteries that supply electric power thereto.

  In particular, many developments have been made on improving the flexible performance of thin batteries. For example, by providing a rubber sheath with higher flexibility on the outside of the outer laminate film of a thin battery, the battery has improved flexibility (Patent Document 3) or provided on one surface of the positive electrode current collector layer. There is one that improves the bending flexibility of the battery by configuring the positive electrode so that the obtained positive electrode active material is divided into a plurality of active material units at regular intervals (Patent Document 4).

  Furthermore, in order to obtain a thin battery that is thin, has a large capacity, and is durable against repeated bending deformation, a groove is formed in a part of the positive electrode plate or the negative electrode plate to improve the bending durability of the electrode plate. Development has been carried out (Patent Document 5).

  While improvement in the flexible performance and bending durability of a thin electronic device and a thin battery mounted thereon is desired, it is indispensable to solve a problem caused by excessive bending of the thin electronic device. However, many of the developments relating to thin electronic devices and thin batteries mounted thereon are focused on improving flexibility, and little is described regarding bending durability. Even when the bending durability is verified, the bending curvature in the test is small, and the durability is often tested by repeatedly bending gently. In other words, no thin electronic device has been developed assuming an excessive deformation enough to bend the thin electronic device at 180 °.

JP 2010-508181 A JP 2007-209428 A Japanese Patent Laid-Open No. 2004-199994 JP 2002-343340 A JP 2003-59486 A

  If a flexible electronic device with a thin battery inside is accidentally stepped on, it will bend greatly due to the flexible performance of the electronic device, but in the case of excessive bending deformation such as trampling, the electrodes of the thin battery inside the device However, there is a problem that the function of the electronic device is degraded due to disconnection / breakage.

  The present invention solves the above-described problem, and realizes a configuration that does not cause a functional deterioration due to a mounted thin battery even when the maximum bending deformation that may occur structurally occurs in the electronic device mounted with a thin battery. For the purpose.

To achieve the above object, the present invention comprises a positive electrode, a negative electrode, a sheet-like electrode group that is interposed between the positive electrode and the negative electrode and includes an electrolyte layer, and an outer package that seals the electrode group. A thin battery-mounted electronic device configured by mounting the thin battery inside an electronic device structure made of an elastic sheet material, wherein the thickness h of the electrode group is 700 μm or less, and from the upper surface of the electrode group The distance H1 from the upper surface of the thin battery-mounted electronic device, and the distance H2 from the lower surface of the electrode group to the lower surface of the thin battery-mounted electronic device are H1 ≦ 34 mm and H2 ≦ 34 mm, 10 ≦ H1 / h, and 10 ≦ H2 / satisfy a relationship of h, the positive electrode has a positive electrode active material, and a positive electrode current collector, the negative electrode is the negative electrode active material, and has a negative electrode current collector, the positive electrode current collector of the negative electrode current collector Thickness An 8 to 30 m, the tensile strength of the positive electrode current collector and the negative electrode current collector is 100～1200MPa, and a longitudinal elastic modulus Ri 7~220GPa der, the elastic sheet member, silicone rubber, butyl rubber, A thin battery-equipped electronic device comprising at least one selected from the group consisting of polyamide, nylon, vinyl, polyester, and polyethylene .

  According to the present invention, there is provided a thin battery-mounted electronic device in which the electrode plate of the thin battery mounted therein is not disconnected or damaged even when the maximum bending deformation that may occur structurally is applied to the thin battery-mounted electronic device. be able to. Thereby, even when the device user unintentionally applies excessive bending deformation to the device, the function of the device due to the battery does not deteriorate, and the user can continue to use the device.

The perspective view which shows the thin battery mounting electronic device which concerns on one embodiment of this invention The perspective view which shows the biological information measuring device which is an example of an electronic device mounted with a thin battery The perspective view which shows the iontophoresis transdermal medication apparatus which is an example of an electronic device mounted with a thin battery The perspective view of the thin battery mounted in the thin battery mounting electronic device which concerns on one embodiment of this invention Sectional drawing of the electrode group inside the thin battery mounted in the thin battery mounting electronic device which concerns on one embodiment of this invention Sectional drawing in XY of the electronic device with a thin battery shown in FIG. Sectional drawing of the state which bent the thin battery mounting electronic device shown in FIG. 1 by XY FIG. 3 is a schematic projection diagram for explaining a method for producing the iontophoretic transdermal administration device shown in FIG.

The first invention in the present invention is a thin film comprising a positive electrode, a negative electrode, a sheet-like electrode group having an electrolyte layer interposed between the positive electrode and the negative electrode, and an outer package for sealing the electrode group. A thin battery-mounted electronic device mounted with a battery, wherein the thickness h of the electrode group, the distance H1 from the upper surface of the electrode group to the upper surface of the thin battery-mounted electronic device, from the lower surface of the electrode group to the lower surface of the thin battery-mounted electronic device Is a thin battery-equipped electronic device characterized by satisfying the relationship of 10 ≦ H1 / h and 10 ≦ H2 / h. With this configuration, it is possible to obtain a thin battery mounted electronic device in which the electrode plate of the thin battery mounted therein is not broken or damaged even when the maximum bending deformation that may occur structurally is applied to the thin battery mounted electronic device. .

  According to a second aspect of the present invention, in the first aspect, the electrode group has a thickness of 92 to 630 μm. The thickness of the electrode group affects the bending flexibility of the thin battery, and the thinner the electrode group, the higher the flexibility of the thin battery. Furthermore, the thickness of the electrode group affects the bending durability. The thinner the electrode group, the higher the bending durability of the thin battery. According to this configuration, it is possible to provide a thin battery-mounted electronic device that can maintain the flexibility and bending durability of the electrode group and is excellent in flexibility and bending resistance.

  According to a third invention of the present invention, in the first or second invention, the positive electrode has a positive electrode active material and a positive electrode current collector, the negative electrode has a negative electrode active material and a negative electrode current collector, Both the positive electrode current collector and the negative electrode current collector have a thickness of 8 to 30 μm. The flexibility of the thin battery electrode group is mainly due to the flexibility of the electrode current collector that is a metal material. Therefore, in order to improve the flexibility of the thin battery electrode group, it is desirable that the electrode current collector is thin. Further, the damage to the electrode group of the thin battery accompanying excessive bending deformation is often the disconnection of the electrode current collector, but the thinner the electrode current collector, the less likely the electrode current collector is disconnected. According to this configuration, a thin battery excellent in flexibility and bending durability can be provided, and the flexibility and bending resistance of an electronic device equipped with a thin battery can be improved.

  According to a fourth invention of the present invention, in the first to third inventions, the positive electrode current collector and the negative electrode current collector have a tensile strength of 100 to 1200 MPa and a longitudinal elastic modulus of 7 to 220 GPa. It is characterized by. According to this configuration, it is possible to maintain the bending and bending durability of the electrode current collector of the electrode group, and the disconnection / disconnection of the electrode current collector of the thin battery electrode group mounted inside the thin battery mounted electronic device Damage can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example embodying the present invention, and does not limit the technical scope of the present invention.

  FIG. 1 shows an example of an electronic device with a thin battery according to the present invention. As shown in FIG. 1, the electronic device 1 with a thin battery is composed of an electronic device structure 2 made of a member such as an elastic sheet material in which at least an electronic component or the like is incorporated, and one or more thin batteries 3. In FIG. 1, electronic components and the like are omitted.

  Examples of thin battery-equipped electronic devices include a biological information measuring device that operates in contact with a living skin, an iontophoresis transdermal administration device, or a battery-type printed advertisement, product packaging, trading card, RFID built-in electronic tag Etc.

  The biological information measuring device includes, for example, a measurement circuit that measures biological information such as body temperature, blood pressure, and pulse, and radio waves when the measured biological information is monitored and biological information indicating a health change is obtained. A wireless transmission circuit that transmits a signal to a hospital, a fire department, or other facilities is configured as a flexible sheet-like holding member. In this case, as shown in FIG. 2, the biological information measuring device 5 includes, for example, a temperature sensor 8, a pressure sensitive element 9, and the like in addition to the thin battery 7 in the thickness direction of the flexible sheet-like holding member 6. There may be a circuit unit including the storage unit 10, the speaker 11, the antenna 12, the push button switch 13, the control IC 14, and the like. The thin electronic device of the present invention may have other rigid or flexible parts other than the battery.

  An iontophoretic transdermal administration device is a device that promotes permeation of a biological membrane by utilizing electrical energy. As shown in FIG. 3, the iontophoresis transdermal administration device 15 includes an elastic sheet material 16 and a thin battery 17 mounted therein. Furthermore, a cathode tank 18 in which an anionic drug is stored and an anode tank 19 in which a cationic drug is stored are provided. The cathode chamber 18 and the anode chamber 19 are exposed on the surface of the elastic sheet material 16. The positive electrode of the thin battery 17 is electrically connected to the anode tank 19 and the negative electrode of the thin battery is electrically connected to the cathode tank 18. The iontophoresis transdermal administration device is attached to the living body, and a voltage of several volts is applied to the cathode tank 18 and the anode tank 19 by the thin battery 17. As a result, the drug is transferred to the skin of the living body. On the other hand, endogenous ions paired with the drug are extracted from the skin into the anode tank 19. In the cathode chamber 18, an electric circuit is established by causing ion exchange of the anionic drug.

  The thin battery mounted inside the thin electronic device will be described below. As shown in FIG. 4, the thin battery 3 includes an electrode group 21, an exterior body 22 that houses the electrode group 21, a negative electrode lead 23 a that extracts current to the outside, and a positive electrode lead 23 b.

  As shown in FIG. 5, the electrode group 21 includes a positive electrode 34, a negative electrode 35, and an electrolyte layer 24 interposed between the positive electrode 34 and the negative electrode 35. The positive electrode 34 is formed of a positive electrode active material 26 provided on one or both of the sheet-like positive electrode current collector 25 and the positive electrode current collector 25. The negative electrode 35 is formed of a negative electrode active material 28 provided on one or both of the sheet-like negative electrode current collector 27 and the negative electrode current collector 27. The positive electrode 34 and the negative electrode 35 are arranged so that the positive electrode active material 26 and the negative electrode active material 28 face each other through the electrolyte layer 24. The negative electrode current collector 27 has a protrusion extending outward from the side surface in the thickness direction, and the negative electrode lead 23a is connected to the protrusion. Similarly, the positive electrode current collector 25 has a protrusion extending outward from the side surface in the thickness direction, and a positive electrode lead 23b is connected to the protrusion. Part of the negative electrode lead 23a and the positive electrode lead 23b is exposed to the outside from the exterior body 22, and the exposed portion acts as a negative electrode terminal and a positive electrode terminal.

  FIG. 6 is a cross-sectional view taken along the line XY of the thin battery-mounted electronic device 1 shown in FIG. FIG. 7 shows the deformation of the thin battery-equipped electronic device 1 at the bent portion when the thin battery-equipped electronic device 1 shown in FIG. It shows the state. However, in FIG.6 and FIG.8, the electrode group 21 shown in FIG.

  In FIG. 6, the thickness of the electrode group 4 is h, the distance from the upper surface of the electrode group to the upper surface of the thin battery-mounted electronic device is H1, and the distance from the lower surface of the electrode group to the lower surface of the electronic device with the thin battery is H2.

  Here, the maximum bending deformation that can occur structurally in the thin battery-equipped electronic device 1 is a state in which the outermost surfaces of the electronic device component 2 are in close contact with each other at least at the bending end as shown in FIG. It shall be said. At this time, the thin battery-mounted electronic device 1, the thin battery 3 mounted therein, and the electrode group 4 inside the thin battery may be deformed with a certain curvature. The curvature at this time is determined by the thickness of the electronic device 1 with a thin battery, the thickness of the thin battery 3, and the thickness of the electrode group 4 inside the thin battery. In other words, the greater the thickness, the smaller the curvature when the maximum bending deformation occurs, and the more gently it bends.

Furthermore, when the electrode group 4 bends with a certain curvature, one surface of the electrode group 4 is stretched and the other surface is stretched and contracted. The degree of expansion / contraction increases as the thickness of the electrode group 4 increases. That is, when the electrode group 4 bends with a certain curvature, the stress generated on the surface of the electrode group 4 increases as the thickness of the electrode group 4 increases. In addition, the disconnection of the electrode group 4 occurs when the stress generated in the electrode group 4 exceeds an allowable value. Therefore, the thickness of the electrode group 4 is preferably thin in order to prevent the destruction of the electrode group 4 inside the mounted battery that occurs when excessive bending deformation is applied to the thin battery mounted electronic device 1.

  Based on the above concept, in the present invention, the thickness h of the electrode group 4, the distance H1 from the upper surface of the electrode group to the upper surface of the thin battery mounted electronic device, and the distance H2 from the lower surface of the electrode group to the lower surface of the thin battery mounted electronic device are 10 By satisfying the relationship of ≦ H1 / h and 10 ≦ H2 / h, the electrode group 4 can be formed even when the thin battery-equipped electronic device 1 undergoes the maximum possible bending deformation such as a folding deformation. It has been found that a thin battery-equipped electronic device 1 that does not break or damage can be provided.

  When H1 / h or H2 / h is smaller than 10, when the maximum bending deformation is applied to the thin battery-mounted electronic device 1, the bending curvature of the electrode group 4 inside the thin battery mounted inside is small. Accordingly, the stress generated on the surface of the electrode group becomes excessively large and the electrode group 4 may be disconnected or damaged. Furthermore, when higher reliability is required, H1 / h or H2 / h is preferably larger. If 20 ≦ H1 / h and 20 ≦ H2 / h, bending deformation is more reliably performed. Thus, it is possible to provide the thin battery-mounted electronic device 1 in which the electrode group 4 inside the mounted battery is not disconnected.

  Furthermore, the electrode group 4 generally uses a metal material for the positive electrode / negative electrode current collector and the like, but these substances are rigid. Therefore, considering the flexibility of the thin battery-mounted electronic device 1, it is desirable that the electrode group 4 be thin. Furthermore, as described above, in order to prevent disconnection of the electrode group 4 due to bending deformation, the thickness of the electrode group 4 is preferably thin. Therefore, the thickness of the electrode group 4 is more preferably 92 to 630 μm based on the above concept. The thickness of the electrode group 4 of the flexible thin battery 3 is 92 μm or more in consideration of the limit value of the thickness of the constituent members. On the other hand, when the thickness of the electrode group 4 is 630 μm or more, the flexibility is remarkably reduced. When the electrode group 4 is forcibly bent, an excessive stress is generated on the surface of the electrode group 4. 4 breaks.

  As a main cause of the functional deterioration of the thin battery 3 that occurs when the electronic device 1 mounted with the thin battery undergoes excessive bending deformation, disconnection / damage of the electrode group 4 inside the battery can be considered. This is often caused by disconnection of the positive electrode current collector 25 and the negative electrode current collector 27 that are generated due to various bending deformations. This is because the disconnection of the electrode current collector is caused by excessive stress generated on the surface of the electrode current collector. When the positive electrode / negative electrode current collector bends with a certain curvature, the stress generated on the surface of the electrode current collector increases as the thickness of the electrode current collector increases. Therefore, in order to prevent disconnection / damage of the electrode group 4 inside the mounted battery due to excessive bending deformation of the thin battery mounted electronic device 1, the positive electrode / negative electrode current collector is preferably thin. On the other hand, the positive electrode current collector 25 and the negative electrode current collector 27 are generally made of a rigid metal material, and it is not preferable to increase the thickness of the current collector in view of the flexibility of the thin battery 3. From the above view, the positive electrode current collector 25 and the negative electrode current collector 27 are more preferably 8 to 30 μm in thickness. When the thickness of the electrode current collector is less than 8 μm, the current collecting ability when a large current is passed is reduced, and when the thickness of the electrode current collector is greater than 30 μm, the flexibility of the electrode group 4 is significantly reduced. When trying to forcibly bend, the electrode current collector is disconnected, which is not preferable.

Furthermore, the more the positive electrode / negative electrode current collector is more vulnerable to bending deformation, the more they are broken or damaged by gentler bending deformation. In general, the stress generated on the surface of the electrode current collector due to bending deformation is proportional to the product of the longitudinal elastic modulus of the electrode current collector, the thickness of the electrode current collector, and the bending curvature of the electrode current collector. growing. Furthermore, when the stress generated in the electrode current collector exceeds the tensile strength of the electrode current collector, the electrode current collector is disconnected. Therefore, in order to prevent disconnection / damage of the electrode group inside the mounted battery due to excessive bending deformation of the thin battery mounted electronic device, it is preferable that the electrode current collector has a small longitudinal elastic modulus and a high tensile strength. From the above view, it is more preferable that the positive and negative electrode current collectors have a longitudinal elastic modulus of 7 to 220 GPa and a tensile strength of 100 to 1200 MPa.

  Furthermore, if an electrode current collector having a longitudinal elastic modulus larger than 220 GPa is used, it is difficult to produce a flexible thin battery. Specific examples of the material that satisfies the above include copper, aluminum (alloy), nickel, stainless steel, titanium, platinum, gold, and carbon.

  Next, the components of the thin battery 3 mounted inside the thin battery-mounted electronic device 1 will be described in detail.

The outer package 22 is preferably made of a film material having lower gas permeability and higher flexibility. Specifically, it is preferable to include a resin layer formed on both sides or one side of the barrier layer, and aluminum, nickel, stainless steel, or an inorganic compound is used as the barrier layer from the viewpoint of strength and gas barrier performance. Is preferred. In general, the thicker the barrier layer, the smaller the gas permeability. Conversely, the thinner the barrier layer, the greater the gas permeability. However, the exterior film whose barrier layer is a metal material is caused by the high longitudinal elastic modulus of the metal material, and the longitudinal elastic modulus of the exterior film is also lowered. Furthermore, regarding the bending rigidity, generally, the thicker the exterior film is, the smaller the thinner the film is. From the viewpoints of bending rigidity and barrier performance, the thickness of the barrier layer of the exterior film is preferably 5 to 50 μm, and the thickness of the resin is preferably 5 to 100 μm. Specifically, as the outer package, an acid-modified PP / PET / Al layer / PET laminate film, an acid-modified PE / PA / Al layer / PET laminate film, an ionomer resin / Ni layer / PE / PET laminate film , Ethylene vinyl acetate / PE / Al layer / PET laminate film, and ionomer resin / PET / Al layer / PET laminate film. In place of the Al layer, an inorganic compound layer such as an Al ₂ O ₃ layer or an SiO ₂ layer may be used.

  Examples of the electrolyte layer 24 include a dry polymer electrolyte in which an electrolyte salt is contained in a polymer matrix, a gel polymer electrolyte in which a polymer matrix is impregnated with a solvent and an electrolyte salt, an inorganic solid electrolyte, and a liquid electrolyte in which an electrolyte salt is dissolved in a solvent. Can also be used.

  A separator can be provided on the electrolyte layer 24 to prevent a short circuit. Various known materials can be used as the separator material, and examples thereof include a porous sheet made of polyethylene, polypropylene, cellulose and the like, a nonwoven fabric, a porous sheet having a predetermined ion permeability, mechanical strength, and insulation.

  The negative electrode active material 28 is particularly preferably lithium or a lithium alloy (hereinafter referred to as lithium negative electrode) which is a high capacity active material. As the lithium alloy, for example, a Li—Si alloy, a Li—Sn alloy, a Li—Al alloy, a Li—Ga alloy, a Li—Mg alloy, or a Li—In alloy is used. From the viewpoint of negative electrode capacity, the proportion of elements other than Li in the lithium alloy is preferably 0.1 to 10% by weight. A known material and composition can be appropriately selected for the negative electrode active material 28. However, when a lithium-based negative electrode, various natural and artificial graphite, silicide, silicon oxide, various alloy materials, etc. are used, a thin battery having a high energy density. It can be. Among these, a lithium-based negative electrode is preferable because a thin battery having a higher capacity and a higher energy density can be realized.

The negative electrode current collector 27 may be an electrolytic metal foil obtained by an electrolytic method or a rolled metal foil obtained by a rolling method. The electrolytic method has the advantages that it is excellent in mass productivity and relatively low in production cost. On the other hand, the rolling method is easy in thickness reduction and is advantageous in terms of weight reduction. The rolled metal foil is suitably used for a thin battery because it has a crystal orientation along the rolling direction and is excellent in bending resistance. Examples of the negative electrode current collector 27 include copper foil, nickel foil, aluminum, aluminum alloy, magnesium alloy, lithium metal, and lithium alloy.

  The negative electrode 34 is obtained by bringing the negative electrode current collector 27 and the negative electrode active material 28 into close contact with each other by, for example, rolling after the negative electrode active material 28 is pressure-bonded, vapor-deposited or coated on the negative electrode current collector 27.

  The positive electrode active material 26 is a mixture layer formed on one surface of the positive electrode current collector 25 and including a positive electrode active material, a binder, and, if necessary, a conductive agent.

  The positive electrode active material 26 includes, for example, manganese dioxide, carbon fluorides, sulfides, lithium-containing composite oxides, vanadium oxides and lithium compounds thereof, niobium oxides and lithium compounds thereof, and conjugates containing organic conductive substances. Polymers, chevrel phase compounds, and olivine compounds are used. Among these, manganese dioxide, fluorocarbons, sulfides, and lithium-containing composite oxides are preferable, and manganese dioxide is particularly preferable.

Examples of the carbon fluorides include fluorinated graphite represented by (CF _w ) _m (wherein m is an integer of 1 or more and 0 <w ≦ 1). Examples of the sulfide include TiS ₂ , MoS ₂ , and FeS ₂ . Examples of the lithium-containing composite oxide include Li _xa CoO ₂ , Li _xa NiO ₂ , Li _xa MnO ₂ , Li _xa Co _y Ni _1-y O ₂ , Li _xa Co _y M _1-y O _z , Li _xa Ni _{1-y M y O z,} Li xb Mn 2 O 4, Li xb Mn 2-y M y O 4 and the like. In the above formulas, M is at least one element selected from the group consisting of Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb and B, and xa = 0 to 1.2, xb = 0 to 2.0, y = 0 to 0.9, z = 2.0 to 2.3. xa and xb are values before the start of charge / discharge, and increase / decrease due to charge / discharge.

  For the positive electrode current collector 25, a metal material such as a metal film, a metal foil, and a metal fiber non-woven fabric is used. Examples of the metal material include silver, nickel, titanium, gold, platinum, aluminum, and stainless steel. These may be used alone or in combination of two or more.

  The thin battery mounted on the thin electronic device may be a primary battery or a secondary battery.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(1) Thin battery A thin battery mounted inside an electronic device will be described below. A thin battery having the structure shown in FIGS. 4 and 5 was produced.

(1-1) Negative Electrode A lithium metal foil (44.5 mm × 59.0 mm, thickness 20 μm), which is a negative electrode active material, is struck into a size of 44.5 mm × 59.0 mm having a 12 mm × 5 mm protrusion. A negative electrode was obtained by pressure bonding to one surface (surface roughness 2.6 μm) of the extracted negative electrode current collector 27 with a linear pressure of 100 N / cm. Thereafter, a copper negative electrode lead 23a having a width of 3.0 mm and a length of 20 mm was ultrasonically welded to the protruding portion.

(1-2) Positive Electrode N-methyl-2-pyrrolidone containing electrolytic manganese dioxide heated at 350 ° C. as a positive electrode active material, acetylene black as a conductive agent, and polyvinylidene fluoride (PVDF) as a binder ( NMP) solution was mixed so that the weight ratio of manganese dioxide: acetylene black: PVDF was 100: 5: 5, and then an appropriate amount of NMP was added to obtain a paste-like positive electrode mixture.

  A positive electrode mixture is applied to one surface of the positive electrode current collector 25, dried at 85 ° C. for 10 minutes to form the positive electrode active material 26, and then compressed with a roll press at a linear pressure of 12000 N / cm. A positive electrode was obtained. However, here, aluminum was used as the positive electrode current collector.

  The positive electrode was cut out to a size of 42.5 mm × 57.0 mm having a tab portion having a width of 12 mm and a length of 5 mm, and then dried under reduced pressure at 120 ° C. for 2 hours. Thereafter, an aluminum positive electrode lead 23b having a width of 5 mm and a length of 20 mm was ultrasonically welded to the protruding portion.

(1-3) Impregnation of gel polymer electrolyte Perchloric acid as an electrolyte salt in a nonaqueous solvent obtained by mixing in a ratio of propylene carbonate (PC): dimethoxyethane (DME) = 6: 4 (weight ratio) Lithium (LiClO ₄ ) was dissolved at 1 mol / kg to produce a liquid electrolyte.

  As a matrix polymer, a copolymer of hexafluoropropylene and polyvinylidene fluoride (hexafluoropropylene content: 7%) is used and mixed at a ratio of matrix polymer: liquid electrolyte = 1: 10 (weight ratio) as a solvent. A gel polymer electrolyte solution was prepared using dimethyl carbonate (DMC).

  The obtained gel polymer electrolyte solution was uniformly applied to both sides of the separator made of porous polyethylene having a thickness of 9 μm and the positive electrode active material, the solvent was volatilized, and the positive electrode and the separator were impregnated with the gel polymer electrolyte.

(1-4) Preparation of electrode group A negative electrode and a positive electrode impregnated with a gel-like nonaqueous electrolyte layer were laminated so that the positive electrode active material 26 and the negative electrode active material 28 face each other with a separator interposed therebetween, and then 90 ° C. The electrode group 21 was produced by hot pressing at 0.1 MPa for 30 seconds.

(1-5) Assembly of thin battery 60.0 mm × 70.0 mm bag-shaped exterior equipped with aluminum foil (thickness 15 μm) as a barrier layer, polyethylene as a sealing layer (thickness 50 μm) and protective layer (thickness 50 μm) The electrode group 21 is disposed in the body 22 so that a part of the positive and negative leads is exposed to the outside from the opening of the film, and then the atmosphere in which the film material in which the electrode group 4 is inserted is adjusted to a pressure of 660 mmHg The opening was heat sealed in this atmosphere. Thereby, a flexible thin battery having a size of 60.0 mm × 70.0 mm was produced.

(2) Manufacturing Method of Thin Battery Mounted Electronic Device Here, a manufacturing method of the iontophoresis transdermal administration device shown in FIG. 3 will be described. FIGS. 8A to 8F are projection views of the iontophoretic transdermal dosage device of FIG. 3 as viewed from the direction of arrow A in order to explain the production process of the iontophoretic transdermal dosage device.

First, an elastic sheet material unit 16a having a shape as shown in FIG. The elastic sheet material unit 16 a includes through holes 18 a and 19 a for fitting the cathode tank 18 and the anode tank 19. The elastic sheet material unit 16a having such a shape can be obtained by injection molding using a thermoplastic elastomer or by injecting a liquid elastomer into a predetermined mold and curing it. Examples of the material for the elastic sheet material unit include silicone rubber, butyl rubber, polyimide, nylon, vinyl, polyester, Teflon (registered trademark), and polyethylene.

  Next, as shown in FIG. 8B, the wiring 29, the electrode terminal 30 connected by the wiring 29, and the wiring 31 and the electrode terminal 32 connected to the wiring 31 are respectively connected to the through holes 18a and 19a. Insert into.

  Next, the anode tank 19 and the cathode tank 18 are fitted into the through-hole 18a and the through-hole 19a so that the drug extraction port is exposed to the outside of the elastic sheet material unit 16a through the through-hole 19a and the through-hole 18a. To do. Thereby, the structure 33 shown in FIG. 8C is obtained.

  Next, as shown in FIG. 8D, the structure 33 is sealed by the elastic sheet material unit 16b so that the wirings 29 and 31 are partially exposed to the outside. For sealing with the elastic sheet material unit 16b, a method of placing the structural body 33 in a predetermined position and injecting and curing a liquid elastomer into the mold, injection insert molding using a thermoplastic elastomer, or the like can be used.

  Further, as shown in FIG. 8E, the thin battery 17 manufactured by the above method is placed on the elastic sheet material unit 16b so that the anode tank 19 and the positive electrode, and the cathode tank 18 and the negative electrode are electrically connected. Further, the wirings 29 and 31 are connected.

  Finally, as shown in FIG. 8F, the thin sheet battery is sealed by the elastic sheet material unit 16c so that the thin battery is completely accommodated in the elastic sheet material unit 16c. At this time, sealing by the elastic sheet material unit 16c uses a method in which the structural body is placed at a predetermined position and liquid elastomer is injected into the mold and cured, or injection insert molding using a thermoplastic elastomer is used. sell.

  Through the above steps, an iontophoresis transdermal administration device 15, which is an electronic device having a thin battery mounted therein, was produced.

(3) Evaluation of electronic device mounted with thin battery In the following, the electronic device mounted with a thin battery according to the present invention is evaluated using the iontophoresis transdermal administration device 15 manufactured by the above manufacturing method.

  Therefore, for simplification of description, in the iontophoresis transdermal administration device 15 shown in FIG. 8F, the surface where the anode tank 19 and the cathode tank 18 are exposed is the lower surface, and the opposite surface is the upper surface. Shall be called. Furthermore, the upper and lower surfaces of the internal thin battery shall follow that. Here, the distance from the upper surface of the thin battery to the upper surface of the iontophoresis transdermal administration device is referred to as H1, and the distance from the lower surface of the thin battery to the lower surface of the iontophoresis transdermal administration device is referred to as H2.

  Furthermore, in bending deformation, the one in which the upper surface of the iontophoretic transdermal administration device is located inside the bending deformation is referred to as bending type A. In addition, the iontophoresis transdermal administration device having the lower surface inside the bending deformation is referred to as a bending type B.

  The bending durability performance against excessive bending of the manufactured thin electronic device is evaluated. In this example, the anti-bending performance of the electronic device against excessive bending is evaluated as follows using the capacity retention rate of the thin battery mounted inside and the bending / bending durability performance.

(3-1) Evaluation of battery discharge capacity maintenance rate First, a thin battery mounted on a thin electronic device was taken out, a discharge test was performed under the following conditions, and a discharge capacity of the mounted battery before the bending test was obtained.

Ambient temperature: 25 ° C
Discharge current density: 250 μA / cm 2 (current value per unit area of positive electrode)
End-of-discharge voltage: 1.8V
Subsequently, a thin electronic device equipped with another battery is bent at 180 ° C. using a press. At this time, the press machine pressure was 0.5 MPa, and the pressurization time was 10 seconds. After the press, the discharge capacity of the mounted battery after the press test was determined by performing the following discharge condition test on the thin battery. And the capacity | capacitance maintenance factor (%) after a press test was derived | led-out by the following formula.

Capacity maintenance rate after bending test (%) = (discharge capacity after bending test / discharge capacity before bending test) × 100
The test was performed using five thin batteries each for bending type A and bending type B, and an average value of five for each bending type was derived.

(3-2) Evaluation of electrode group bending / bending durability performance A press test similar to the evaluation of the discharge capacity retention rate was performed on the thin electronic device. The mounted battery was taken out of the thin electronic device after the press test and disassembled to confirm the number of cells in which the electrode group was disconnected or damaged.

  The test was performed using five thin batteries each for bending type A and bending type B, and an average value of five for each bending type was derived.

[Example 1]
A thin battery comprising a 170 μm thick electrode group in which the positive electrode current collector is made of aluminum having a thickness of 8 μm (longitudinal elastic modulus 70 GPa, tensile strength 150 MPa) and the negative electrode current collector is made of copper having a thickness of 8 μm (longitudinal elastic modulus 150 GPa, tensile strength 250 MPa). Was produced based on the production procedure. Furthermore, an iontophoresis transdermal administration device was produced based on the above production procedure using the produced thin battery. At this time, a thin battery-mounted electronic device was manufactured by adjusting the injection amount of the elastic sheet material unit so that the distance H1 was 1700 μm and H2 was 3400 μm.

[Example 2]
Example 1 except that the thickness of the positive electrode current collector is 30 μm, the thickness of the negative electrode current collector is 30 μm, the thickness of the electrode group is 630 μm, and the distance H1 is 6300 μm and H2 is 6300 μm. Thus, an electronic device with a thin battery was produced.

[Example 3]
The positive electrode current collector has a thickness of 8 μm nickel (longitudinal elastic modulus 200 GPa, tensile strength 450 MPa), the negative electrode current collector has a thickness of 8 μm aluminum (longitudinal elastic modulus 70 GPa, tensile strength 150 MPa), and the electrode group has a thickness of 170 μm. A thin battery-mounted electronic device was manufactured in the same manner as in Example 1 except that the distance H1 was 1700 μm and H2 was 3400 μm.

[Example 4]
A thin battery-mounted electronic device was fabricated in the same manner as in Example 1 except that the distance H1 was 34000 μm and H2 was 34000 μm.

[Example 5]
Example 1 except that the thickness of the positive electrode current collector is 30 μm, the thickness of the negative electrode current collector is 30 μm, the thickness of the electrode group is 700 μm, and the distance H1 is 7000 μm and H2 is 7000 μm. Thus, an electronic device with a thin battery was produced.

[Example 6]
Example 1 except that the thickness of the positive electrode current collector is 35 μm, the thickness of the negative electrode current collector is 35 μm, the thickness of the electrode group is 400 μm, and the distance H1 is 4000 μm and H2 is 4000 μm. Thus, an electronic device with a thin battery was produced.

[Comparative Example 1]
Example 1 except that the thickness of the positive electrode current collector is 30 μm, the thickness of the negative electrode current collector is 30 μm, the thickness of the electrode group is 200 μm, and the distance H1 is 1000 μm and H2 is 2000 μm. Thus, an electronic device with a thin battery was produced.

Sample conditions of the thin battery-mounted electronic devices produced in Examples 1 to 6 and Comparative Example 1 are shown in (Table 1), and the evaluation results are shown in (Table 2).

As shown in Table 2, the thin battery-mounted electronic devices produced in Examples 1 to 6 are superior in discharge capacity maintenance ratio after the press test as compared with the thin battery-mounted electronic devices produced in Comparative Example 1. ing. Furthermore, although the thin battery mounted electronic device produced in Comparative Example 1 was found to be disconnected in the battery electrode group after the press test, the thin battery mounted electronic device produced in Examples 1 to 6 was subjected to the press test. Even after that, no disconnection was found in the electrode group of the battery.

  In Example 4, H1 / h and H2 / h are 200, and the distances H1 and H2 from the electrode group surface to the device surface are excessively large with respect to the thickness h of the electrode group. After the press test, no breakage or damage was observed in the electrode group. However, as in Example 4, excessively increasing H1 and H2 leads to excessively increasing the thickness of the device, which is undesirable because it hinders the flexibility of the thin battery-equipped electronic device, More preferably, H1 / h and H2 / h are 100 or less.

  Example 5 and Example 6 are cases where the thickness of the electrode group is 630 μm or more, or the thickness of the electrode current collector is 30 μm or more. In the case of Example 5 and Example 6, the electrodes were also tested after the press test. No disconnection of the group occurred, but the discharge capacity was deteriorated due to the damage of the electrode group due to excessive bending. Therefore, in order to more reliably prevent disconnection / damage of the electrode group, the thickness of the electrode group and the electrode current collector is preferably thin. The thickness of the electrode group is 630 μm or less, and the thickness of the electrode current collector is reduced. By setting the thickness to 30 μm or less, disconnection / damage of the electrode group can be more reliably prevented.

  It is considered that the deterioration of the discharge capacity of the battery after the press test in Comparative Example 1 is due to disconnection / damage of the mounted battery electrode group by the press test.

  From the above results, the thickness h of the electrode group and the upper surface of the electrode group are prevented in order to prevent deterioration of the function of the device due to disconnection / damage of the battery electrode group when the thin electronic electronic device is excessively bent. The distance H1 from the upper surface of the electronic device with a thin battery and the distance H2 from the lower surface of the electrode group to the lower surface of the electronic device with a thin battery must satisfy the relationship of 10 ≦ H1 / h and 10 ≦ H2 / h. I understand.

  In the battery-mounted thin electronic device of the present invention, even when the maximum bending deformation that may occur in the structure occurs in the device, the function of the device does not deteriorate due to disconnection / damage of the battery electrode group. Thereby, even if the user of the thin battery-equipped electronic device steps on the device, the function of the thin battery-equipped electronic device does not deteriorate, thereby improving the reliability of the thin battery-equipped electronic device.

DESCRIPTION OF SYMBOLS 1 Thin battery mounting electronic device 2 Electronic device structure 3, 7, 17 Thin battery 4 Electrode group 5 Biological information measuring device 6 Holding member 8 Temperature sensor 9 Pressure sensitive element 10 Memory | storage part 11 Speaker 12 Antenna 13 Pushbutton switch 14 Control IC
DESCRIPTION OF SYMBOLS 15 Iontophoresis transdermal administration device 16 Elastic sheet material 18 Cathode tank 19 Anode tank 21 Electrode group 22 Exterior body 23a Negative electrode lead 23b Positive electrode lead 24 Electrolyte layer 25 Positive electrode collector 26 Positive electrode active material 27 Negative electrode collector 28 Negative electrode active Substance 29, 31 Wiring 30, 32 Electrode terminal 33 Structure

Claims (2)

An electronic device comprising a positive electrode, a negative electrode, and a thin battery that is interposed between the positive electrode and the negative electrode and includes a sheet-like electrode group including an electrolyte layer and an exterior body that seals the electrode group. A thin battery-mounted electronic device configured to be mounted inside a structure, wherein the electrode group has a thickness h of 700 μm or less,
A distance H1 from the upper surface of the electrode group to the upper surface of the thin battery mounted electronic device, and a distance H2 from the lower surface of the electrode group to the lower surface of the thin battery mounted electronic device are:
H1 ≦ 34 mm and H2 ≦ 34 mm,
Satisfying the relationship of 10 ≦ H1 / h and 10 ≦ H2 / h,
The positive electrode has a positive electrode active material and a positive electrode current collector, the negative electrode has a negative electrode active material and a negative electrode current collector,
Both the positive electrode current collector and the negative electrode current collector have a thickness of 8 to 30 μm,
The tensile strength of the positive electrode current collector and the negative electrode current collector is 100～1200MPa, and a longitudinal elastic modulus Ri 7~220GPa der,
The thin battery-equipped electronic device , wherein the elastic sheet material is composed of at least one selected from the group consisting of silicone rubber, butyl rubber, polyimide, nylon, vinyl, polyester, and polyethylene . The thin battery-mounted electronic device according to claim 1, wherein the electrode group has a thickness of 92 to 630 μm.