JP2010073533A - Chargeable and dischargeable battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chargeable and dischargeable battery excellent in output characteristics. <P>SOLUTION: The chargeable and dischargeable battery is formed by forming a battery active material layer 2 on a surface of a fibrous material 1 having electron conductivity, coating it with a material 3 not having electron conductivity but having ion conductivity, forming a counter electrode active material layer 4, and then forming a material layer 5 having electron conductivity thereon. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a chargeable / dischargeable battery.

  Currently, a secondary battery using a general-purpose aqueous solution as an electrolyte includes a plate-like positive electrode, a separator, and a plate-like negative electrode. In general, an alkaline secondary battery is configured using an aqueous solution of caustic potash, caustic soda, or the like in which lithium hydroxide is dissolved, and a lead acid battery is configured using dilute sulfuric acid.

  As the shape of the battery, a rectangular shape, a coin shape, and a cylindrical shape are common. In the square type and the coin type, positive electrodes and negative electrodes are alternately arranged via separators, and a positive electrode terminal and a negative electrode terminal are taken out collectively. In particular, this structure is common in lead acid batteries. Alkaline batteries have many cylindrical types, and an electrode group consisting of a positive electrode, a separator, and a negative electrode is wound and inserted into a battery case, and a lid and a can are insulated to serve as positive and negative terminals, respectively. Further, in the lithium ion battery, such a configuration is adopted for both the cylindrical type and the square type.

  As electrodes, alkaline secondary batteries such as nickel-cadmium batteries and nickel-hydrogen batteries that are widely used have a relatively thick thickness of about 0.65 to 0.8 mm for high capacity use. For high output, a lower one of about 0.4 to 0.6 mm is used.

  In addition, as the positive electrode, a sintered or foamed nickel electrode is well known as an electrode of these alkaline secondary batteries, and as a negative electrode, a paste is applied to a current collector having a two-dimensional structure such as a punching metal. A pressurized paste-type electrode is mainly employed. As the positive electrode current collector, the sintered type is a sintered body obtained by sintering carbonyl nickel on a punching metal or the like, and the foamed nickel type is a resin after nickel plating is applied to the foamed resin. Is a porous body obtained by incineration removal. In addition, many porous bodies with irregularities formed by machining have been proposed, but have not reached the practical level. In the lead storage battery, the paste type is the mainstream, and an electrode having a large thickness is employed as compared with the alkaline secondary battery.

  As the separator, in the alkaline secondary battery, a polyamide nonwoven fabric having a thickness of about 80 to 200 μm or a polyolefin-based nonwoven fabric subjected to hydrophilic treatment is mainly used. In lead-acid batteries, paper, porous polyolefin plates and glass fiber cloth are used, and generally it is necessary to impregnate a large amount of sulfuric acid directly involved in the charge / discharge reaction. A thicker separator is also used.

  In a lithium ion battery or the like, as the current collector, an aluminum foil is used for the positive electrode, a copper foil is used for the negative electrode, a lithium metal oxide is applied to the former, and a carbon material is applied to the latter. Used. As an electrolyte, a solution in which a lithium salt is dissolved in an organic solvent is common.

  Further, there has been proposed a battery having a completely different battery structure from a conventional electrode group composed of a positive electrode, a separator, and a negative electrode, and using a fibrous body having electronic conductivity as a current collector (Patent Document 1). reference). This battery is particularly intended for high output.

  In addition, either the long negative electrode material formed by forming an electrode active material on the outer peripheral portion of each electrode or the positive electrode material is used as a core material, and the other outer periphery is interposed with a polymer solid electrolyte. A cord-shaped battery in which electrode materials are provided coaxially and sealed with an exterior material has been proposed (see Patent Document 2).

The configuration of this battery is basically the same as that of a general-purpose Luclanche type dry battery. That is, in the dry battery, a positive electrode material is provided at the center, a negative electrode material is provided at the peripheral portion, and an electrolyte is provided between them. In Patent Document 2, it is proposed that the electrolyte is a solid electrolyte and the whole is formed into a flexible cord.
JP 2003-317794 A JP 2001-110445 A

  The present invention intends to further improve the battery proposed in Patent Document 1 to enable higher output.

  Note that the battery configuration proposed in Patent Document 2 cannot achieve high output. Although the specific thickness of the electrode is not described in Patent Document 2, a cord-like battery is formed by one positive electrode and one negative electrode, and is not for high output. For example, in a general-purpose nickel-hydrogen battery or nickel-cadmium battery, the thickness of the positive electrode is larger than that of the negative electrode, but for high power use, the thickness is about 0.6 mm at most, and the negative electrode is thinner than that. What is made up of pieces deviates from the concept of codes.

  On the other hand, in a general-purpose nickel-hydrogen battery or nickel-cadmium battery, the thickness of the electrode is about 400 μm even if it is the thinnest, and the diffusion of ions and electrons moving through the active material is rate limiting. It is difficult to increase the output.

  In a lead storage battery, since both the electrode and the separator are thicker, it is more difficult to increase the output.

  In the conventional plate-like electrode, in order to reduce the thickness, it is necessary to stack a large number of electrodes in the case of a square battery, and in the case of a cylindrical battery, it is necessary to wind the electrode with a long length. From this point of view, there was a limit to higher output.

  An object of the present invention is to provide a battery having a fiber configuration and capable of being charged / discharged, which has a higher output.

  As a result of intensive studies to solve the above problems, the present inventor has found that the battery active material has extremely low electronic conductivity or has a large amount of material that must be moved to react. As a result, high output becomes possible, and it has been found that the movement path of electrons and the like can be made small, and the present invention has been completed.

That is, this invention provides the battery which can be charged / discharged as shown below.
Item 1. Charge / discharge is possible by forming a battery active material layer on the surface of a fibrous material with electron conductivity, covering it with an ion conductive material without electron conductivity, and forming a counter electrode active material layer. Battery.
Item 2. A battery active material layer is formed on the surface of a fibrous material having electron conductivity, and is coated with a material having no electron conductivity and ion conductivity, and a counter electrode active material layer is formed thereon, and an electron is formed thereon. A chargeable / dischargeable battery formed by forming a conductive material layer.
Item 3. A battery active material layer is formed on the surface of a fibrous material having electron conductivity, and is coated with a material having no electron conductivity and ion conductivity, and a counter electrode active material layer is formed thereon, and an electron is formed thereon. A chargeable / dischargeable battery that is formed by forming a conductive material layer and taking out terminals from the fibrous material at the center and the material layer at the outer periphery.
Item 4. A battery active material layer is formed on the surface of a fibrous material having electron conductivity, and is coated with a material having no electron conductivity and ion conductivity, and a counter electrode active material layer is formed thereon, and an electron is formed thereon. Formed by forming a conductive material layer, from the fibrous material in the center and the material layer of the outer periphery, each cell is taken as a unit cell, and this unit cell is arranged in a bundle or a fabric shape, A chargeable / dischargeable battery comprising a positive terminal and a negative terminal.
Item 5. Item 5. The chargeable / dischargeable battery according to any one of Items 1 to 4, wherein the current collector made of a fibrous substance having electron conductivity has one or more current collectors.
Item 6. Item 6. The chargeable / dischargeable battery according to any one of Items 1 to 5, wherein the fibrous substance has a diameter of 0.1 to 300 µm.
Item 7. Item 6. The chargeable / dischargeable battery according to any one of Items 1 to 5, wherein the fibrous substance has a diameter of 0.5 to 200 μm.
Item 8. Item 8. The chargeable / dischargeable battery according to any one of Items 1 to 7, wherein the fibrous substance having electron conductivity is made of a metal, a carbon-based fiber, an organic fiber having a metal-plated surface, or an inorganic material.
Item 9. Item 9. The chargeable / dischargeable battery according to any one of Items 2 to 8, wherein the fibrous substance having electron conductivity is a positive electrode current collector and the outer peripheral material layer is a negative electrode current collector.
Item 10. Item 10. The chargeable / dischargeable battery according to Item 9, wherein an active material layer mainly composed of nickel hydroxide is formed on the surface of a fibrous material having electron conductivity.
Item 11. Item 10. The chargeable / dischargeable battery according to Item 9, wherein the fibrous substance having electron conductivity is made of nickel or a nickel alloy.
Item 12. Item 9. The chargeable / dischargeable battery according to any one of Items 2 to 8, wherein the fibrous substance having electron conductivity is a negative electrode current collector, and the outer peripheral material layer is a positive electrode.
Item 13. The chargeable / dischargeable battery according to claim 12, wherein the fibrous material having electron conductivity is a negative electrode current collector and a layer mainly composed of a hydrogen storage alloy is formed.
Item 14. Item 10. The chargeable / dischargeable battery according to Item 9, wherein a layer mainly composed of a hydrogen storage alloy is formed on a porous layer having ion conductivity.
Item 15. Item 13. The chargeable / dischargeable battery according to Item 12, wherein the fibrous substance having electron conductivity is a negative electrode current collector and a layer mainly composed of zinc is formed.
Item 16. Item 10. The chargeable / dischargeable battery according to Item 9, wherein a layer mainly composed of zinc is formed on a porous layer having ion conductivity.
Item 17. Item 13. The chargeable / dischargeable battery according to Item 12, wherein the negative electrode current collector is made of nickel, copper, carbon fiber, or graphite fiber.
Item 18. Item 18. The chargeable / dischargeable battery according to any one of Items 9 to 17, wherein the battery is impregnated with an aqueous caustic solution as an electrolytic solution.
Item 19. Item 5. The chargeable / dischargeable battery according to any one of Items 1 to 4, wherein the ion-conductive substance is a solid electrolyte or a gel electrolyte.

  Hereinafter, the present invention will be described in detail.

  The basic structure of the chargeable / dischargeable battery according to the present invention is that a fibrous material having electron conductivity is used as an active material holder and a current collector, a battery active material layer is formed on the surface, and an electron conductivity is formed thereon. Without covering with an ion conductive material, a counter electrode active material layer is formed thereon, and a current collector layer is further formed thereon.

  The number of fibrous substances in the center may be one, or a plurality (for example, about 2 to 30) may be used together. The thickness of the fibrous material to be used is related to high output, and the structure is not limited to a cylindrical shape, and a shape such as a prism can also be adopted, but when converted to a fiber diameter, preferably 0.1 to 300 μm. About, more preferably, about 0.5 to 200 μm is employed. If it is thinner than this, it may be difficult to handle industrially, and if it is thicker than this, the output characteristics may not be expected. Also, by using a fibrous current collector with such a diameter, the active material layer has a cylindrical shape unlike a foil-like current collector such as a lithium ion battery, for example. During this period, no shear stress is generated in the circumferential direction at the boundary between the two materials due to expansion or the like, and the active material layer is difficult to peel off. Even if the active material layer is peeled off, the active material layer surrounds the current collector in a cylindrical shape, so that the contact does not become poor and the internal resistance is suppressed. As a result, high output and long life are possible.

  In the present invention, the capacity increases as the fibrous material is lengthened. However, since the fiber diameter is small, the capacity is as small as 1 to 100 mAh, for example, in one cell. Therefore, a plurality of combinations of a pair of positive electrodes and negative electrodes are used according to the application. Hereinafter, this pair is referred to as a unit cell.

  Such unit cells are arranged in a bundle or a fabric is formed, and a positive electrode terminal and a negative electrode terminal are attached. If the positive electrode current collector of this unit cell is integrated, and further the negative electrode current collector is integrated, it will be arranged in parallel, and the capacity will increase at a constant voltage, which is actually used in this configuration. The

  Furthermore, if a unit cell with the outer periphery as a positive electrode and a unit cell with the outer periphery as a negative electrode are combined, they are connected in series, so that the voltage increases with a constant capacity. In this case, it is necessary to take care to isolate the unit cell so that it does not become a common electrolyte. In applications requiring a high voltage, such as preliminary and emergency use, they are first connected in parallel and then in series.

  In this case, the terminals may be arranged in a bundle and assembled into a cylindrical shape or a rectangular shape, or the unit cell may be made into a woven shape, and the positive electrode terminal and the negative electrode terminal may be attached.

  The fibrous material as the current collector that forms the center of the negative electrode needs to be electronically conductive and resistant to electrolytes for the negative electrode. In addition, if the full charge is required for the positive electrode, oxidation resistance is required. It is. As the material of the fibrous substance, metal, carbon fiber, organic fiber whose surface is metal-plated, or inorganic material is selected.

  In the configuration of the present invention, when the central portion is a positive electrode, the outer peripheral portion is a negative electrode. Conversely, when the central portion is a negative electrode, the outer peripheral portion is a positive electrode. In a secondary battery using an aqueous electrolyte, at the end of charging, a function of returning oxygen from the positive electrode back to water is required at the negative electrode. Therefore, it is necessary to increase the capacity. Is preferred.

  However, on the contrary, there is an advantage that carbon-based fibers, particularly graphite fibers, which can be easily obtained can be used as the material of the fibrous substance when the negative electrode is the central part. That is, as the material of the fibrous substance when the central portion is a negative electrode, copper, carbon fiber, graphite fiber, or the like can be used in the alkaline secondary battery in addition to the material used for the positive electrode such as nickel. For lead-acid batteries, carbon, lead, and lead alloys can be used.

  The battery of the present invention is most suitable for a battery using an alkaline electrolyte, and nickel hydroxide is most practically used as a positive electrode material. Nickel hydroxide is the main material. In addition to electron conductivity and alkali resistance as a current collector, oxidation resistance is also important. Nickel alloys such as nickel and stainless steel, and materials plated with nickel are selected. It is. In addition, in the case of a lead storage battery, lead, lead alloy fiber, carbon fiber, or the like can be used.

  As one negative electrode, a hydrogen storage alloy is most suitable as an active material, and cadmium is the next most promising. In applications where life is not so important, zinc and other materials that are superior in potential and manufacturing method can be used. If it is not necessary to use a sealed type such as a spare type that does not fully charge and discharge, inexpensive and resource-rich iron can be used. It can be used. In a lead-acid battery, lead-based powder is used for both the positive electrode and the negative electrode.

  As an electrolyte, a solid electrolyte or a gel electrolyte can be applied in addition to a caustic aqueous solution of an alkaline secondary battery and a dilute sulfuric acid of a lead storage battery.

  An ion exchange membrane, a porous fluororesin, a non-woven fabric such as polyethylene or polypropylene, etc. can be used as a substance having no electron conductivity and ion conductivity, that is, a separator. A semipermeable membrane such as polyvinyl alcohol can also be used for an open battery system using an alkaline electrolyte.

  An example is a resin made porous by extracting a solvent from a resin dissolved in a solvent using a resin soluble in a solvent soluble in water, alcohol, etc. By selecting, it becomes a separator suitable for long life.

  Thus, the battery obtained by forming the active material, the ion conductive layer, the counter electrode active material layer, and the current collector layer as required, mainly in the electron conductive fibrous material, By making the diameter of the material on the order of μm, the active material layer can be made as thin as several μm to several tens of μm and the moving distance of ions and electrons can be made extremely small. A secondary battery cell is obtained.

  This fibrous material is used as one pole, and provided with a current collecting layer of a counter electrode provided outside, and a plurality of each are connected together to obtain a power source with a desired capacity. That is, first, a current collector made of a fibrous material is batched, and a counter current collector layer is batched, and unit cells are connected in parallel to obtain a desired capacity. This is a single cell, which is filled with an electrolyte and sealed. Here, the active material layer is preferably in a pressurized state. Note that when a non-fluid gel or solid is used as the electrolyte, peeling of the active material from the current collector can be suppressed.

  In addition, the secondary battery capable of charging and discharging according to the present invention covers the surface of an electron conductive fibrous material with an active material, and further has an ion conductive porous material, a counter electrode active material, a current collector. It is a unit cell composed of a layer and, if necessary, a current collector.

  For example, when using a metal battery case that is used for a battery with a normal cylindrical structure or a square structure, this is one of the poles. Then, the outer current collector can be omitted as in a general-purpose alkaline secondary battery. That is, an electron conductive fiber, an active material layer, a separator, a counter electrode active material layer in the center part, or an electron conductive fiber in the center part, and then an active material layer, a separator, a counter electrode active material layer, and an electron conduction layer in that order. It becomes the configuration of the battery case. Moreover, the structure of the active material layer, a separator, a counter electrode active material layer, and a battery case can also be employ | adopted in order on the electron conductive fiber of a center part.

  In addition, it is also possible to assemble the battery in a woven shape by taking out the positive electrode and negative electrode terminals from the warp and weft as the warp and weft.

  In the configuration of the battery of the present invention, for example, the positive electrode active material is nickel hydroxide, the negative electrode active material is a hydrogen storage alloy, the positive electrode active material is nickel hydroxide, the negative electrode active material is cadmium, the positive electrode active material is nickel hydroxide, and the negative electrode The present invention can also be applied to batteries in which the active material is iron, the positive electrode active material is nickel hydroxide, and the negative electrode active material is zinc. Furthermore, the present invention can be applied to lead acid batteries in which the positive electrode active material is lead dioxide and the negative electrode active material is lead.

  As the fibrous substance having electron conductivity, an electron conductive substance such as carbon fiber or metal fiber, organic fiber with metal plating on the surface, inorganic fiber, fibrous plastic, rubber or the like can be used. Here, in addition to the cylindrical structure, the fibrous material includes a rod-shaped material having a sufficiently small cross-sectional diameter, an elongated foil-shaped material, and the like. A battery active material layer can be formed on the surface of these cylindrical, rod-like, and foil-like materials, for example, with a thickness of 10 μm or less.

  In the above configuration, a unit in which unit cells are arranged or laminated as a woven fabric can be compressed and consolidated in a battery cell. For example, the basic unit can be made into a compacted state by being bound with a band or string-like body made of a porous or non-porous insulator, or a meltable or non-meltable insulator.

  When the unit cells are woven into one cell or a bundle, a plain weave, twill weave, toncap weave, etc. can be used.

  When forming the battery active material layer on the surface of the fibrous material, one fibrous material may be used, or a plurality of fibrous materials may be used together.

  As a method for forming the battery active material layer on the surface of the fibrous material, a so-called slurry or paste method in which the active material powder is applied in the form of a slurry of an aqueous solution is applicable to various active materials. high. Here, a thickener and a binder are generally used. The most common thickener is carboxymethylcellulose (CMC), and various natural polysaccharides are also used.

  Various types of synthetic resins have been studied as paste-type binders, but any oxidation resistance and electrolyte resistance may be used. Polyolefin and fluororesin are preferable for the positive electrode, and synthetic rubber (SBR) can also be used for the negative electrode. The amount of these binders added is about 0.5 to 5% by weight.

  In addition, there is a method of directly fixing the active material together with the resin. An example of the active material is nickel hydroxide. When nickel hydroxide is used at 130 ° C. or higher, the utilization factor decreases. Therefore, a thermoplastic resin having a softening temperature of 120 ° C. or lower, a resin having a curing temperature from room temperature to 120 ° C., and a resin that dissolves in a solvent having an evaporation temperature of 120 ° C. or lower. Etc. are used. As the resin, polyethylene and polypropylene are preferable.

  Further, ethylene-vinyl acetate copolymer, epoxy resin, polyurethane resin, unsaturated polyester resin, phenol resin, and the like can be mentioned. Since all of these have problems in oxidation resistance, they are more suitable for the negative electrode than for the positive electrode.

  Examples of the solvent for dissolving the resin include organic solvents such as toluene, xylene, NMP, DMF, acetone, and alcohol, which are problematic in terms of production method and environment as compared with aqueous solutions, but can be used. In this case, after applying a solution obtained by dissolving the active material and the resin in a solvent to the surface, the solvent may be removed by heating under reduced pressure or normal pressure.

  Moreover, in order to improve the electroconductivity of an active material layer, you may add electroconductive materials, such as carbon black, carbon fiber, carbon foil, carbon whisker, nickel microparticles, nickel foil, nickel whisker. As for nickel hydroxide, a cobalt compound is most effective.

  As a means for adding such a conductive material (conductive agent) to the active material layer, generally, a method of mixing the active material powder and the conductive agent powder and adding a resin dissolved in a solvent is common. . In addition, there are a method of mixing and dispersing a conductive agent and a dissolved resin, a method of mixing and dispersing a conductive agent and a solvent, and then dissolving and mixing and dispersing the resin. An active material layer having different characteristics can be formed by changing the amount and type of the resin and the solvent.

  Further, hot dipping can be used as a means for forming an active material layer on the surface of the fibrous material. In the hot dipping method, the fibrous material may be continuously supplied and plated on the surface, or the fibrous material may be supplied in batches and plated on the surface. In this case, it is possible to coat the surface with precipitates having different characteristics by using an electrolytic bath different in composition type, concentration, temperature and the like a plurality of times. In addition, precipitates having different characteristics can be coated on the surface by changing the treatment time.

  Furthermore, when a hydrogen storage alloy is used as the negative electrode active material of the alkaline secondary battery on the surface of the fibrous material, a sintering method, sputtering, vapor deposition, or the like can be employed.

  In addition, regarding nickel hydroxide as the positive electrode active material, the electrolytic deposition method (electrodeposition) by electrolysis used in the method for producing a sintered nickel electrode can be used. In this case, the surface can be coated with precipitates having different characteristics by using electrolytic baths of different types, concentrations, pH, temperature, etc., multiple times. Further, the surface can be coated with precipitates having different characteristics by changing the current density. Furthermore, it is possible to suspend the battery active material as fine particles in the electrolytic bath, and to incorporate the battery active material into the plating metal by the eutectoid plating method to cause eutectoid.

  As a specific example of a battery structure in which a fibrous conductive material is used as a current collector of one electrode and an active material layer, a separator, a counter electrode active material layer, and a current collecting layer are provided around the conductive material, When the body has a cylindrical structure, for example, a diameter of about 5 to 30 μm is selected, a thickness of 5 to 40 μm is selected as the active material layer, and a thickness of 10 to 60 μm is selected as the separator, thereby enabling high output charge / discharge. Become.

  The chargeable / dischargeable battery of the present invention can be applied to a secondary battery using an aqueous solution as an electrolyte, specifically a nickel-hydrogen battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a lead storage battery, etc. It is. Furthermore, the present invention can also be applied to non-aqueous electrolyte secondary batteries typified by lithium ion batteries.

  The chargeable / dischargeable battery according to the present invention is intended for portable, stationary, and mobile power supplies. For example, the power supply is used as a spare power supply that is used under conditions that do not fully charge and discharge, and that requires a large current discharge. It is an optimal battery.

  The chargeable / dischargeable battery of the present invention is extremely excellent in output characteristics.

  Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications.

  FIG. 1 is a schematic cross-sectional view of a unit cell parallel to a central fibrous current collector 1. The shape is basically cylindrical. 1 is a fibrous current collector (fibrous material), 2 is an active material layer thereof, 3 is a separator made of a material having no electron conductivity and ion conductivity, and 4 is a counter electrode active material layer. Reference numeral 5 denotes a counter electrode current collector (an outer peripheral material layer), which may serve as a battery case. In the case of a nickel-hydrogen battery, when 2 is a hydrogen storage alloy electrode, 4 is a nickel active material, and 5 is a current collector that may also serve as a battery case. In this embodiment, since the active material layer 2 is arranged in a circular shape around the fibrous current collector 1, even if some deviation occurs between the fibrous current collector 1 and the active material layer 2. Insulation, electrical conductivity is ensured and durability is high.

  FIG. 2 is a schematic cross-sectional view in parallel with the fibrous current collector 1, showing a state in which the unit cell shown in FIG. 1 is connected in parallel or in series in order to increase the capacity or voltage. 1 is a fibrous current collector (fibrous material), 2 is an active material layer thereof, 3 is a separator made of a material having no electron conductivity and ion conductivity, and 4 is a counter electrode active material layer. Reference numeral 5 denotes a counter electrode current collector (an outer peripheral material layer), which may serve as a battery case. In the present embodiment, the diameter of the fibrous current collector is 0.1 to 300 μm, preferably 0.5 to 200 μm, and is used by being assembled (laminated) in this way. Here, if all the active materials used as the fibrous current collector of the unit cell are the same, the capacity is increased by parallel connection. In order to increase the voltage, the assembled batteries may be connected in series.

  FIG. 3 is a schematic view of a cross section perpendicular to the fibrous current collector 1. One column is a unit cell, 1 is a fibrous current collector (fibrous material), 2 is an active material layer thereof, 3 is a separator made of a material having no electron conductivity and ionic conductivity, and 4 is a counter electrode active. It is a material layer. For example, in the case of a nickel-hydrogen battery, when 2 is a negative electrode, it becomes a hydrogen storage alloy electrode, and 4 becomes a nickel electrode. 5 is a nickel electrode current collector that also serves as a battery case. This is an example in which the connection between the unit cells is parallel. In this case, if the outer active material layer is conductive, the current collector 5 can be omitted.

  FIG. 4 and FIG. 5 are schematic cross-sectional views when a unit cell group configured by using a plurality of fibrous current collectors 1 in each unit cell is connected in series. Reference numeral 6 in FIG. 5 denotes a connection plate arranged for connecting each unit cell. As in these embodiments, when a plurality of fibrous current collectors 1 are used, even if a short circuit occurs, only the shorted fibrous current collector burns out and the short circuit is eliminated.

  In order to make the battery have a high capacity or a high voltage, the unit cells may be connected in parallel or in series as described above.

  As the first embodiment of the present invention, the most practically effective nickel-hydrogen battery is taken as an example. In the first embodiment, a specific example will be described in which a paste-type nickel electrode is used as a positive electrode and a hydrogen storage alloy is used as a negative electrode. A nickel fiber was used as the fibrous material to form a positive electrode. This was added to cobalt hydroxide ground to an average particle size of 5 μm and nickel hydroxide powder ground to an average particle size of 5 μm to a CMC aqueous solution of about 0.5% by weight as a thickener and about 3% by weight as a binder. Were immersed in a slurry prepared using a fluororesin dispersion of, and then pulled up and dried to form a positive electrode active material layer.

  Subsequently, this was pulled up by being immersed in a solution in which polyethersulfone (PES) was dissolved in dimethyl sulfoxide (DMSO). DMSO was extracted with water, and PES was solidified to form a porous membrane. The average thickness was 20 μm.

After pulverizing an MmNi _5- based alloy powder known as a negative electrode to an average particle size of 4 μm, using CMC as a thickener, and styrene butadiene rubber (SBR) as a binder, dipping and pulling up It dried and the negative electrode alloy layer was formed.

  In the first embodiment, since the negative electrode has conductivity, it is used as a conductive layer simultaneously with the active material. On top of that, if a nickel layer is formed as a conductive layer by performing nickel electroless plating after a known activation treatment, the conductivity is improved.

  As shown in FIGS. 3 and 4, the unit cell obtained in this way has a positive electrode with the nickel fiber cross-section exposed and a negative electrode with the hydrogen storage alloy layer exposed. Inserted into the bath. The battery case becomes the negative terminal. The positive electrode terminal was collectively welded to a metal lid to constitute a battery. It is preferable that the negative electrode and the battery case are sufficiently pressed. This has the effect of sufficiently performing electrical connection between the electrode and the battery case, and suppressing deterioration of discharge characteristics due to swelling of the electrode due to repeated charge / discharge and dropping of the active material. The shape of the battery case may be cylindrical, rectangular or flat, and there is no limitation on the shape.

  Here, an aqueous electrolyte solution was used, and a 30% by weight aqueous caustic potash solution containing lithium hydroxide (for example, 10 g / liter) was injected.

  6 shows another example of battery manufacture according to the second embodiment of the present invention. A nickel active material obtained by electrolysis different from that in the first embodiment was formed on the nickel fiber as the base material by electrolytic deposition. That is, in a nickel nitrate bath, electrolysis was performed using nickel fibers as a cathode and a nickel plate as an anode, and nickel / nickel hydroxide was electrolytically deposited on the nickel surface. In the following, the above fiber was dipped in a resin solution in which PES was dissolved in DMSO and pulled up. This was immersed in water, DMSO was extracted with water, and PES was solidified to form a porous membrane. This was immersed in a slurry prepared by adding cadmium powder to cadmium oxide powder, adding SBR as a binder, and adding a CMC aqueous solution as a thickener, and then immediately drying to form a negative electrode active material layer. . On top of this, a nickel layer may be formed by electroless plating. However, even in this state, the entire battery can be charged with the conductivity of the mixed cadmium metal by charging in a metal battery case.

  The unit cell thus obtained was inserted in a metal battery case with the positive electrode exposed in a cross section of nickel fiber and the negative electrode exposed in a mixed layer of cadmium and cadmium oxide. As in the first embodiment, the battery case serves as a negative electrode terminal. The positive electrode terminal was collectively welded to a metal lid to constitute a battery. Also in this second embodiment, it is preferable that the negative electrode and the battery case are sufficiently pressed. This has the effect that the electrical connection between the electrode and the battery case is sufficiently performed, and the deterioration of the discharge characteristics due to the swelling of the electrode due to repeated charging and discharging and the dropping of the active material is suppressed.

  As a third embodiment of the present invention, a nickel plate is attached as a current collector outside the unit cell having the configuration described in the first embodiment.

  With this configuration, the positions of the positive terminals of each unit cell were aligned, and the negative electrode current collectors at the opposite positions were also arranged. The positive electrode terminal and negative electrode terminal of the unit cell were pressed against each current collector. Welding is a more preferred means. If each terminal is taken out and wrapped with a laminate, a flat battery is obtained. The electrolyte was impregnated in advance in the separator.

  Next, details of charging and discharging will be described for the battery of the present embodiment. In this embodiment, by forming a thin battery active material layer on the surface of a fibrous material having electron conductivity such as nickel fiber, it becomes possible to extremely shorten the moving distance of electrons and ions. Compared with conventional batteries, the diffusion of ions and ions has been greatly accelerated, and the high power charge / discharge has been greatly improved. For example, in a prismatic nickel-hydrogen battery having a nominal capacity of 10 Ah, the comparative sintered nickel-hydrogen battery has a discharge voltage of 10 C and an average voltage of 1 V, whereas the battery of this embodiment has a voltage of 1.2 V and 20 C. In the discharge, the former was 0.9V, while the battery of this embodiment showed 1.1V. The utilization rate of the battery of the present embodiment was also 92%, while the comparative nickel-hydrogen battery at 10C was 80% at a final voltage of 0.8V. At 20C, they were 70% and 85%, respectively.

  From the above, it can be seen that the battery of the present invention has a high output. In addition, charging with a large current is possible.

It is a schematic sectional drawing which shows one Embodiment of this invention. It is a schematic sectional drawing which shows other embodiment of this invention. It is another schematic sectional drawing which shows other embodiment of this invention. It is a schematic sectional drawing which shows other embodiment of this invention. It is a schematic sectional drawing which shows other embodiment of this invention.

Explanation of symbols

1 Fibrous current collector (fibrous material)
2 Active Material Layer 3 Separator 4 Counter Electrode Active Material Layer 5 Counter Electrode Current Collector (Outer Material Layer)
6 Connection board

Claims (19)

  Charge / discharge is possible by forming a battery active material layer on the surface of a fibrous material with electron conductivity, covering it with an ion conductive material without electron conductivity, and forming a counter electrode active material layer. Battery.   A battery active material layer is formed on the surface of a fibrous material having electron conductivity, and is coated with a material having no electron conductivity and ion conductivity, and a counter electrode active material layer is formed thereon, and an electron is formed thereon. A chargeable / dischargeable battery formed by forming a conductive material layer.   A battery active material layer is formed on the surface of a fibrous material having electron conductivity, and is coated with a material having no electron conductivity and ion conductivity, and a counter electrode active material layer is formed thereon, and an electron is formed thereon. A chargeable / dischargeable battery that is formed by forming a conductive material layer and taking out terminals from the fibrous material at the center and the material layer at the outer periphery.   A battery active material layer is formed on the surface of a fibrous material having electron conductivity, and is coated with a material having no electron conductivity and ion conductivity, and a counter electrode active material layer is formed thereon, and an electron is formed thereon. Formed by forming a conductive material layer, from the fibrous material in the center and the material layer of the outer periphery, each cell is taken as a unit cell, and this unit cell is arranged in a bundle or a fabric shape, A chargeable / dischargeable battery comprising a positive terminal and a negative terminal.   The chargeable / dischargeable battery according to any one of claims 1 to 4, wherein there is one or a plurality of current collectors made of a fibrous substance having electron conductivity.   The chargeable / dischargeable battery according to claim 1, wherein the fibrous substance has a diameter of 0.1 to 300 μm.   The diameter of a fibrous substance is 0.5-200 micrometers, The battery which can be charged / discharged of any one of Claims 1-5.   The chargeable / dischargeable battery according to any one of claims 1 to 7, wherein the fibrous substance having electron conductivity is made of a metal, a carbon-based fiber, an organic fiber having a metal-plated surface, or an inorganic material.   The chargeable / dischargeable battery according to claim 2, wherein the fibrous substance having electron conductivity is a positive electrode current collector, and the outer peripheral material layer is a negative electrode current collector.   The chargeable / dischargeable battery according to claim 9, wherein an active material layer mainly composed of nickel hydroxide is formed on the surface of a fibrous substance having electron conductivity.   The chargeable / dischargeable battery according to claim 9, wherein the fibrous substance having electron conductivity is made of nickel or a nickel alloy.   The chargeable / dischargeable battery according to claim 2, wherein the fibrous substance having electron conductivity is a negative electrode current collector, and the outer peripheral material layer is a positive electrode.   The chargeable / dischargeable battery according to claim 12, wherein the fibrous substance having electron conductivity is a negative electrode current collector and a layer mainly composed of a hydrogen storage alloy is formed.   The chargeable / dischargeable battery according to claim 9, wherein a layer mainly composed of a hydrogen storage alloy is formed on a porous layer having ion conductivity.   The chargeable / dischargeable battery according to claim 12, wherein the fibrous substance having electron conductivity is a negative electrode current collector and a layer mainly composed of zinc is formed.   The chargeable / dischargeable battery according to claim 9, wherein a layer mainly composed of zinc is formed on a porous layer having ion conductivity.   The chargeable / dischargeable battery according to claim 12, wherein the current collector of the negative electrode is made of nickel, copper, carbon fiber, or graphite fiber.   The chargeable / dischargeable battery according to any one of claims 9 to 17, wherein the battery is impregnated with a caustic aqueous solution as an electrolytic solution.   The chargeable / dischargeable battery according to any one of claims 1 to 4, wherein the ion-conductive substance comprises a solid electrolyte or a gel electrolyte.

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