JP6735538B2 - Electrode manufacturing method and battery manufacturing method - Google Patents

Description

The present invention relates to electrode precursors. More specifically, the present invention relates to an electrode precursor that can be preferably used for a battery including a zinc negative electrode, an electrode that includes the electrode precursor, a battery that includes the electrode, and a method for producing these.

In recent years, the importance of batteries is rapidly increasing in many industries, from small portable devices to large-scale applications such as automobiles, and they have an advantage mainly in terms of their capacity, energy density, and conversion to secondary batteries (storage batteries). Various new battery systems have been developed and improved.
Among these various batteries, a zinc negative electrode using a zinc species as a negative electrode active material has been studied for a long time with the spread of batteries. Examples of batteries that use zinc negative electrodes include primary batteries, secondary batteries, and air batteries. For example, air/zinc batteries that use oxygen in the air as the positive electrode active material (the positive electrode does not hold the positive electrode active material), the positive electrode. Research and development of nickel-zinc batteries that use nickel-containing compounds as active materials, manganese-zinc batteries and zinc-ion batteries that use manganese-containing compounds as positive electrode active materials, and silver-zinc batteries that use silver oxide as positive electrode active materials. Especially, the air/zinc primary battery, the manganese/zinc primary battery, and the silver/zinc primary battery have been put into practical use and widely used in the world.
A secondary battery constructed using a zinc negative electrode is inexpensive and has a high energy density, and thus is expected to be widely used in the world.

In a secondary battery (storage battery), each of the positive electrode and the negative electrode is usually provided with a raw material called an active material that causes an electrochemical reaction. The amount of the active material becomes the chargeable/dischargeable capacity. When constructing a battery such as such a secondary battery, first, a current collector is prepared, and a mixture containing an active material prepared in the form of a slurry or paste is applied to the current collector by coating or rolling. .. Finally, the positive electrode and the negative electrode are opposed to each other via the separator, and the electrolytic solution is injected to form a battery such as a secondary battery (see, for example, Patent Document 1).

International Publication No. 2013/27767

As described above, a conventional electrode such as a zinc negative electrode is a slurry-like or paste-like (hereinafter also referred to as slurry-like) electrode precursor in order to bring the current collector and the active material into sufficient electrical contact. Is applied onto a current collector and then pressed by a rolling roll or the like to be molded, or the electrode precursor is impregnated into holes of a current collector which is a metal foam to be molded. Since the slurry or paste is in an unstable state, it changes with time such as settling of a solid substance and solidification due to evaporation of water during storage. In order to prevent this, it is common to prepare an electrode precursor in the form of a slurry and then apply it to a current collector immediately.

From the above, in order to assemble a battery such as a secondary battery, not only the battery assembling equipment, but also equipment and raw materials for consistently performing from the preparation of the electrode precursor in the form of a slurry to the formation of the electrode Various resources such as personnel and time were needed. Further, after the formation of the electrode, the active material layer obtained and the current collector could not be easily separated. Therefore, when adjusting the active material layer to various dimensions according to the design of the battery, the active material layer is cut together with the current collector, and it is difficult to collect and recycle only the unnecessary portion of the active material. It was Further, conventionally, only the active material layer portion has not been distributed as a product.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for easily manufacturing a battery, having a higher degree of freedom when forming an electrode, and using a material without waste.

The present inventor examined various methods of easily manufacturing a battery, having a higher degree of freedom in forming an electrode, and using a material without waste, and focusing on an electrode precursor which is a material for forming an active material layer of an electrode. did.
The present inventor has determined that an electrode precursor having a solvent content of 0.1% by mass or less, and disposing the electrode precursor in contact with a current collector to form an electrode. The present inventor functions as an electrode by disposing an electrode precursor having a solvent content of 0.1% by mass or less in contact with the current collector so that the current collector and the active material electrically contact with each other. It has been found that a battery having excellent charge/discharge characteristics can be manufactured.

Then, the present inventor, since the electrode precursor having a solvent content of 0.1% by mass or less is stabilized in a solid state, unlike the conventional electrode precursor in the form of a slurry, it is stored. However, it has been found that there is no change with time as described above, and there is no need to form an electrode by integrating with the current collector immediately after preparation. As a result, equipment and various resources for consistently performing from the preparation of the electrode precursor in the form of slurry to the formation of the electrode (integration with the current collector) are unnecessary. Further, the collector can be freely selected at the time of forming the electrode, and the electrode precursors can be overlapped with each other as necessary, and as a result, various performances of the obtained electrode can be appropriately adjusted. .. Then, at the time of electrode formation, only the active material layer portion can be cut to a desired size according to the design of the battery, and the scraps and the like generated when the unnecessary portion is cut can be collected and remolded. It can be easily recycled, and the electrode precursor can be used up without waste. The electrode precursor stabilized in the solid state as described above is distributed only in the active material layer portion without being integrated with the current collector. The present inventor has reached the present invention by discovering the above-mentioned advantages and realizing that the above-mentioned problems can be solved satisfactorily.

That is, the present invention is an electrode precursor containing an active material and a polymer, wherein the electrode precursor has a solvent content of 0.1% by mass or less and is arranged so as to be in contact with a current collector. It is an electrode precursor used to form a layer.
The present invention also provides an electrode including a current collector and an active material layer, wherein the active material layer is formed by disposing the electrode precursor of the present invention in contact with the current collector. It is an electrode.
The invention is further a battery constructed using the electrodes of the invention.
The present invention is also a method for producing an electrode including a current collector and an active material layer, wherein the method includes an active material and a polymer and has a solvent content of 0.1% by mass or less. Is a method for manufacturing an electrode, which comprises a step of arranging the electrode precursor as described above so as to be in contact with a current collector to form the electrode.
The present invention is also a method for producing a battery, wherein the method comprises placing an electrode precursor containing an active material and a polymer and having a solvent content of 0.1% by mass or less in contact with a current collector. Then, the method for producing a battery includes the steps of forming an electrode including a current collector and an active material layer, and the step of forming a battery using the electrode.
The present invention is described in detail below.
It should be noted that a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

<Electrode precursor>
The electrode precursor of the present invention is characterized by having a solvent content of 0.1% by mass or less.
The electrode precursor of the present invention preferably has a solvent content of 0.05% by mass or less, more preferably 0.03% by mass or less, and further preferably 0.01% by mass or less. The lower limit of the solvent content is not particularly limited and may be 0% by mass.
The solvent content means the content of the solvent in 100% by mass of the entire electrode precursor.
The solvent content, when the electrode precursor of the present invention is prepared through a drying step such as heating, calculate the mass of the solvent remaining after the solvent component is evaporated by the drying step, the mass of the solvent, the electrode It can be calculated as a percentage of the total mass of the precursor.

Examples of the solvent contained in the electrode precursor of the present invention include water; organic solvents such as ethanol, acetone, isopropyl alcohol, butanol, butyl acetate, and N-methylpyrrolidone, and one or more of these may be used. it can.

The electrode precursor of the present invention is arranged so as to be in contact with a current collector and used, and does not have a current collector.
The current collector refers to a current collector that is arranged closer to a path, which is electrically connected to the positive electrode and the negative electrode than the active material layer, in each of the positive electrode and the negative electrode when a battery is formed.
The electrode precursor of the present invention is a molded body, and the shape thereof can be a shape suitable as an active material layer depending on the design of the battery and is not particularly limited, but it is preferably, for example, columnar, and The columnar shape is more preferable, and the block shape (rectangular solid shape) is further preferable.

The electrode precursor of the present invention does not have a current collector and usually has an electric resistance of 1×10 ⁶ Ωcm or more, but as long as it is arranged so as to be in contact with the current collector, the electric resistance The lower limit of is not particularly limited, and may include, for example, a conductive auxiliary agent described later and have an electric resistance of less than 1×10 ⁶ Ωcm. From the viewpoint of exhibiting the conductive performance as an electrode, the electric resistance is, for example, preferably 1×10 ⁹ Ωcm or less, and more preferably 1×10 ⁸ Ωcm or less.
The electric resistance is measured by a tester.

In the electrode precursor of the present invention, the ratio of the apparent density to the true density is preferably 20% or more, more preferably 40% or more, and further preferably 60% or more. Further, the ratio of the apparent density to the true density is preferably 90% or less, and more preferably 80% or less.

Examples of the polymer contained in the electrode precursor of the present invention include hydrocarbon moiety-containing polymers such as polyethylene and polypropylene, aromatic group-containing polymers such as polystyrene; ether group-containing polymers such as alkylene glycol; polyvinyl alcohol and Hydroxyl group-containing polymers represented by poly(α-hydroxymethyl acrylate); amide bond-containing polymers represented by polyamide, nylon, polyacrylamide, polyvinylpyrrolidone, N-substituted polyacrylamide, etc.; represented by polymaleimide, etc. Imido bond-containing polymer; carboxyl group-containing polymer represented by poly(meth)acrylic acid, polymaleic acid, polyitaconic acid, polymethyleneglutaric acid, etc.; poly(meth)acrylic acid salt, polymaleic acid salt, polyitaconic acid salt, poly Carboxylate-containing polymers typified by methylene glutarate; halogen-containing polymers such as polyvinyl chloride, polyvinylidene fluoride and polytetrafluoroethylene; polymers in which epoxy groups such as epoxy resins are bonded by ring opening; sulfones AR ¹ R ² R ³ B (A represents N or P. B represents a halogen anion or anion such as OH ^−. R ¹ , R ² and R ³ are the same or different. Represents an alkyl group having 1 to 7 carbon atoms, a hydroxyalkyl group, an alkylcarboxyl group, and an aromatic ring group. R ¹ , R ² , and R ³ may combine to form a ring structure). Polymers containing a quaternary ammonium salt or a quaternary phosphonium salt, which are represented by polymers to which groups are bonded; ion-exchangeable polymers used for cation/anion exchange membranes; natural rubber; styrene-butadiene rubber ( SBR) and the like artificial rubber; cellulose, cellulose acetate, hydroxyalkyl cellulose (eg, hydroxyethyl cellulose), carboxymethyl cellulose, chitin, chitosan, alginic acid (salt) and the like saccharide; polyethyleneimine, an amino Group-containing polymer; Carbamate group-containing polymer; Carbamide group-containing polymer; Epoxy group-containing polymer; Heterocycle and/or ionized heterocycle-containing polymer; Polymer alloy; Heteroatom-containing polymer; Low molecular weight surfactant And so on. These polymers act as a binder for the electrode precursor and can prevent the occurrence of cracks in the resulting electrode, for example.

As the polymer contained in the electrode precursor of the present invention, among the above polymers, a polymer containing at least one selected from the group consisting of a halogen atom, a carboxyl group, a hydroxyl group and an ether group is preferable. Polymers having carboxylates instead of carboxyl groups are also preferred. More preferred are fluorine-containing polymers such as polyvinylidene fluoride and polytetrafluoroethylene. When the fluorine-containing polymer is used, it becomes easy to form a paste when kneading the active material and the polymer, and it becomes easy to handle. In addition, since the fiber formation of the polymer is promoted, the effect of preventing the occurrence of cracks in the obtained electrode becomes remarkable.

A polymer is radical polymerization, radical (alternating) copolymerization, anionic polymerization, anionic (alternating) copolymerization, cationic polymerization, cationic (alternating) copolymerization, graft polymerization, graft (alternating) copolymerization from a monomer corresponding to its constitutional unit. , Living polymerization, living (alternating) copolymerization, dispersion polymerization, emulsion polymerization, suspension polymerization, ring-opening polymerization, cyclization polymerization, polymerization by light, UV or electron beam irradiation, metathesis polymerization, electrolytic polymerization, etc. .. When these polymers have a functional group, the functional group may be present in the main chain and/or the side chain, and may be present as a binding site with the crosslinking agent. These polymers may be used alone or in combination of two or more.
The polymer is a layered double water compound or an organic cross-linking agent compound other than the ester bond, amide bond, ionic bond, van der Waals bond, agostic interaction, hydrogen bond, acetal bond, ketal bond, ether bond, peroxide. Crosslinked via a bond, a carbon-carbon bond, a carbon-nitrogen bond, a carbon-oxygen bond, a carbon-sulfur bond, a carbamate bond, a thiocarbamate bond, a carbamide bond, a thiocarbamide bond, an oxazoline moiety-containing bond, a triazine bond, etc. May be.

The polymer preferably has a weight average molecular weight of 200 to 7,000,000. Thereby, the ionic conductivity and flexibility of the electrode precursor can be adjusted. The weight average molecular weight of the polymer is more preferably 400 to 65,000,000, and further preferably 500 to 5,000,000.
The weight average molecular weight can be measured by gel permeation chromatography (GPC).

The proportion of the polymer in the electrode precursor is preferably 0.1 to 30 mass% with respect to the total 100 mass% of the active material and the polymer (solid content) contained in the electrode precursor. The proportion of the polymer is more preferably 0.3 to 15% by mass, further preferably 0.5 to 10% by mass, and particularly preferably 1 to 5% by mass.
In addition, when the electrode precursor of the present invention is densified by reducing the voids generated during dehydration by rolling, it is possible to further suppress the occurrence of cracks due to the voids in the obtained electrode, and thus the polymer in the electrode precursor. It is more preferable to use a form in which the conductivity ratio is improved by reducing the ratio of (for example, less than 3% by mass).

The electrode active material contained in the electrode precursor of the present invention preferably contains zinc species or cadmium species. When the electrode precursor of the present invention contains these metal species as the active material, the active material layer formed from the electrode precursor and the current collector can be integrated, and has excellent charge/discharge characteristics. Batteries can be manufactured. Here, the metal species means a simple metal or a metal compound.
Examples of the cadmium species include simple metal cadmium, and examples of the zinc species include the following.
The active material contained in the electrode precursor of the present invention is preferably a zinc species. As a result, the electrode formed by disposing the electrode precursor containing the zinc species so as to contact the current collector has a structure in which the zinc ionizes and moves during a process such as charging and discharging, so that the current collector and the active material layer are initially formed. Even if there is a gap between and, the gap is filled and the adhesion is improved. As a result, a battery having excellent charge/discharge characteristics can be manufactured. The zinc negative electrode has a unique property that dendrite precipitates, but on the other hand, it has a property that the active material layer and the current collector can be integrated during use of the battery, and the active material and the current collector are rolled. It is not important to adhere them in advance by such means. When the present invention is applied to a zinc negative electrode, this property can be effectively utilized. In addition to the zinc negative electrode, the active material layer and the current collector can be similarly integrated as long as the electrode is an electrode (for example, a cadmium negative electrode) in which the active material is ionized and dissolved/precipitated when used in a battery.

As the zinc species contained in the electrode precursor of the present invention, in addition to metallic zinc alone, a zinc-containing compound may be used as long as it can be used as an active material, for example, zinc oxide (JIS K1410 (2006)). 1 type/2 type/3 types), zinc hydroxide, zinc sulfide, tetrahydroxyzinc alkali metal salt, tetrahydroxyzinc alkaline earth metal salt, zinc halogen compound, zinc carboxylate compound, zinc alloy, zinc solid solution, Belongs to Groups 1 to 17 of the periodic table represented by zinc borate, zinc phosphate, zinc hydrogen phosphate, zinc silicate, zinc aluminate, carbonic acid compounds, hydrogen carbonate compounds, nitric acid compounds, sulfuric acid compounds, etc. Examples thereof include zinc (alloy) compounds having at least one element selected from the group consisting of elements, organic zinc compounds, and zinc compound salts.
Among these, zinc oxide (1 type/2 types/3 types specified in JIS K1410 (2006)), zinc hydroxide, tetrahydroxyzinc alkali metal salt, tetrahydroxyzinc alkaline earth metal salt, zinc halogen compound, Zinc carboxylate compound, zinc alloy, zinc solid solution, zinc borate, zinc phosphate, zinc silicate, zinc aluminate, zinc carbonate, selected from the group consisting of elements belonging to Groups 1 to 17 of the periodic table More preferred are zinc (alloy) compounds having at least one element. The zinc alloy may be a zinc alloy used in (alkaline) dry batteries and air batteries. The zinc-containing compound may be used alone or in combination of two or more.

The zinc species used as the active material preferably has an average particle size of 1 nm to 500 μm. The thickness is more preferably 5 nm to 200 μm, still more preferably 10 nm to 100 μm, and particularly preferably 10 nm to 60 μm.
The average particle size of zinc species can be measured using a particle size distribution measuring device.

The ratio of the metal species contained in the electrode precursor of the present invention as an active material is 50 to 99.9 mass% with respect to the total 100 mass% of the active material contained in the electrode precursor and the polymer (solid content). preferable. When the ratio of the active material is within such a range, the electrode formed using the electrode precursor will be more sufficient in terms of battery capacity. The ratio of the metal species is more preferably 55 to 99.5% by mass, and further preferably 60 to 99% by mass.

The electrode precursor of the present invention, in order to suppress water decomposition side reactions that may occur when a water-containing electrolytic solution is used in a battery such as a secondary battery prepared by using the element precursor or these A compound containing the element as a constituent element may be included. Specific elements include Al, B, Ba, Bi, Br, C, Ca, Cd, Ce, Cl, Cu, Eu, F, Ga, Hg, In, La, Mg, Mn, N, Nb, Nd, Examples thereof include Ni, P, Pb, S, Sb, Sc, Si, Sm, Sn, Sr, Ti, Tl, Y and Zr.

The electrode precursor of the present invention preferably further contains a conductive auxiliary agent. By including the conductive additive, the conductive performance of the active material layer formed by using the electrode precursor is enhanced, and the active material contained in the active material layer can be effectively used to further increase the capacity of the battery. ..
Examples of the conductive aid include conductive carbon, conductive ceramics, zinc/zinc dust/zinc alloy/(alkaline) (storage) zinc used in dry batteries and air batteries (hereinafter also collectively referred to as metallic zinc). It is possible to use one or more of metals such as copper, brass, nickel, silver, bismuth, indium, lead and tin.

As the conductive carbon, graphite such as natural graphite and artificial graphite, glassy carbon, amorphous carbon, graphitizable carbon, non-graphitizable carbon, carbon nanofoam, activated carbon, graphene, nanographene, graphene nanoribbon, fullerene, carbon black, Graphitized carbon black, Ketjen black, vapor grown carbon fiber, pitch carbon fiber, mesocarbon microbeads, carbon coated with metal, carbon coated metal, fibrous carbon, boron-containing carbon, nitrogen-containing carbon, multi-layer/ Single-walled carbon nanotubes, carbon nanohorns, vulcanes, acetylene black, carbon hydrophilically treated by introducing oxygen-containing functional groups, SiC-coated carbon, surface-treated carbon by dispersion/emulsion/suspension/microsuspension polymerization, microcapsules Examples thereof include carbon.

Examples of the conductive ceramics include a compound containing at least one selected from Bi, Co, Nb, and Y, which is fired with zinc oxide.

Among the above conductive assistants, natural graphite, graphite such as artificial graphite, graphitizable carbon, non-graphitizable carbon, graphene, carbon black, graphitized carbon black, Ketjen black, vapor grown carbon fiber, pitch-based carbon fiber , Mesocarbon microbeads, fibrous carbon, multi-wall/single-wall carbon nanotubes, vulcan, acetylene black, carbon hydrophilically treated by introducing oxygen-containing functional groups, metal zinc, copper/brass/nickel/silver/bismuth/indium -Metal such as lead and tin is preferable. The metallic zinc may be used in an actual battery such as an alkaline (storage) battery or an air battery, or may be one whose surface is treated with another element or carbon, or may be alloyed. It may have been done. It may be a solid solution. The above-mentioned conductive aid may be used alone or in combination of two or more.

The metallic zinc can also function as an active material. In other words, in the process of using the battery, the metal zinc, which is a conductive aid, undergoes a redox reaction and also functions as an active material. Similarly, in the process of using the battery, metallic zinc produced from the zinc-containing compound that is the active material also functions as a conductive additive. Metal zinc and a zinc-containing compound, which are added as a mixture at the stage of preparing an electrode such as a negative electrode, substantially function as an active material and a conductive auxiliary agent during the process of using the battery.

In order to suppress the decomposition side reaction of water when the water-containing electrolytic solution is used, the conductive additive contains a simple substance of the same element as the above-mentioned specific element or a compound having these elements as constituent elements. It may be one. When conductive carbon is used as one of the conductive assistants, specific elements include Al, B, Ba, Bi, C, Ca, Cd, Ce, Cu, F, Ga, In, La and Mg. , Mn, N, Nb, Nd, Ni, P, Pb, S, Sb, Sc, Si, Sn, Ti, Tl, Y and Zr are preferable.

The content ratio of the conductive additive in the electrode precursor is preferably 0.0001 to 100 mass% with respect to 100 mass% of the active material in the electrode precursor. When the content ratio of the conductive additive is in such a range, better battery performance is exhibited when the electrode including the active material layer is used in the battery. It is more preferably 0.0005 to 60% by mass, and even more preferably 0.001 to 40% by mass.
In addition, when using metallic zinc as a component of an electrode precursor, it considers metallic zinc as an electroconductive auxiliary agent rather than an active material, and calculates it. Further, in the electrode precursor of the present invention using a zinc species as an active material, metallic zinc produced in the process of using the battery from zinc oxide, zinc hydroxide or the like which is a zinc-containing compound is used as a conductive auxiliary agent in the system. Although it also has a function, it is not considered as a conductive auxiliary agent here because it is not a zero-valent metal zinc at the time of preparing an electrode precursor or an electrode (zinc negative electrode). That is, the preferable content ratios of the active material and the conductive additive are calculated by considering the zinc-containing compound at the time of preparing the electrode precursor and the electrode (zinc negative electrode) as the active material and the metallic zinc as the conductive additive.

The electrode precursor of the present invention may contain one or more components other than zinc species, polymers, and solvents.
Other components are not particularly limited, and examples thereof include alumina, silica, conductive ceramics, and the like. Other components can function to assist ionic conductivity.

The electrode precursor of the present invention is prepared by kneading various components of the electrode precursor described above into an electrode precursor in the form of a slurry, dehydrating and rolling the same, and heating in an oven or the like as necessary. be able to. As described above, the electrode precursor of the present invention is preferably obtained through the rolling process. By rolling, the voids generated during dehydration in the electrode precursor can be reduced and the density can be increased, and the generation of cracks due to the voids can be suppressed in the resulting electrode. Dehydration/rolling may be performed via a nonwoven fabric.

<Electrode>
The present invention also provides an electrode including a current collector and an active material layer, wherein the active material layer is formed by disposing the electrode precursor of the present invention described above in contact with the current collector. It is also used as an electrode.
“The electrode precursor is placed in contact with the current collector to form the active material layer” is as described later.
The electrode formed using the electrode precursor of the present invention can be formed more easily than the conventional one.

The thickness of the active material layer included in the electrode of the present invention is preferably 0.1 mm or more, more preferably 0.2 mm or more, and further preferably 0.3 mm or more. Further, the thickness of the active material layer is preferably 10 mm or less.
Note that the thickness of the active material layer here means the thickness of the entire active material layer, and in the case of an active material layer having a structure formed by stacking a plurality of electrode precursors, the thickness of the entire active material layer is means. Note that the active material layer included in the electrode of the present invention can be formed by stacking electrode precursors that do not include a conductive member for collecting current, and thus has a high degree of freedom during formation, and thus, for example, the active material layer It is possible to easily form an electrode having a large thickness and a large capacity.
The thickness of the active material layer can be measured with a micrometer or the like.

The preferable shape of the active material layer included in the electrode of the present invention is the same as the preferable shape of the electrode precursor of the present invention described above.

The active material layer included in the electrode of the present invention may have a structure formed from only one electrode precursor or may have a structure formed by stacking a plurality of electrode precursors.
In the active material layer having a structure formed by stacking a plurality of electrode precursors, the types and proportions of various components of each electrode precursor may be the same or different. If necessary, it is possible to produce an active material layer having a distribution of the component ratio in the thickness direction of the active material layer by laminating a plurality of electrode precursors having different ratios of the specific components.

As the current collector constituting the electrode of the present invention, (electrolytic) copper foil, copper mesh (expanded metal), copper foam, punching copper, copper alloy such as brass, brass foil, brass mesh (expanded metal), foam brass , Punching brass, nickel foil, corrosion resistant nickel, nickel mesh (expanded metal), punching nickel, metal zinc, corrosion resistant metal zinc, zinc foil, zinc mesh (expanded metal), (punching) steel plate, non-woven fabric with conductivity; Ni・Zinc, Sn, Pb, Hg, Bi, In, Tl, brass added (electrolytic) copper foil, copper mesh (expanded metal), foamed copper, punched copper, copper alloy such as brass, brass foil, brass mesh (Expanded Metal) / Foamed Brass / Punching Brass / Nickel Foil / Corrosion Resistant Nickel / Nickel Mesh (Expanded Metal) / Punching Nickel / Metal Zinc / Corrosion Resistant Metal Zinc / Zinc Foil / Zinc Mesh (Expanded Metal) / (Punching) Steel Plate / Nonwoven Fabric ; Ni, Zn, Sn, Pb, Hg, Bi, In, Tl, brass plated (electrolytic) copper foil, copper mesh (expanded metal), foamed copper, punched copper, copper alloy such as brass, brass foil・Brass mesh (expanded metal) ・Foamed brass ・Punching brass ・Nickel foil ・Corrosion resistant nickel ・Nickel mesh (expanded metal) ・Punching nickel ・Metal zinc ・Corrosion resistant metal zinc ・Zinc foil ・Zinc mesh (expanded metal) ・(Punching) Steel plates/nonwoven fabrics; silver; materials used as current collectors and containers for alkaline (storage) batteries and zinc-air batteries.

<Method of manufacturing electrode>
The present invention further provides a method for producing an electrode including a current collector and an active material layer, the method including an active material and a polymer, and having a solvent content of 0.1% by mass or less. It is also a method for producing an electrode, which comprises a step of arranging the electrode precursor which is in contact with a current collector to form the electrode.
In the present specification, "the electrode precursor is arranged so as to be in contact with the current collector to form the electrode" means that in the present specification, the electrode precursor is coated, pressure-bonded, bonded, piezoelectric, rolled, on the current collector. It is not necessary to stretch or melt, and it may be arranged so that at least a part of the solid-state electrode precursor is in contact with at least a part of the current collector. Thereby, the active material and the current collector are electrically connected to each other, and an electrode capable of driving the battery can be formed. Even when the electrode of the present invention has a structure formed by laminating a plurality of electrode precursors, it is not necessary to bind the electrode precursors by using a binder or the like. A plurality of electrode precursors may be superposed.
The electrode precursor of the present invention may be pressure-bonded onto the current collector to form an active material layer, or a binder or the like may be used to bind the electrode precursors.

When the electrode precursor is placed in contact with the current collector, the portion of the electrode precursor in contact with the current collector (the bottom area when the electrode precursor is a columnar shape such as a rectangular parallelepiped) is the current collector. When it is larger than the portion in contact with the electrode precursor, the electrode precursor of the present invention can be cut to easily adjust the size. The area of the portion of the electrode precursor that comes into contact with the current collector can be appropriately determined according to the design of the battery.
Incidentally, the member such as a cut end generated at the time of cutting is pulverized by a known method, re-kneaded by adding a solvent such as water, and then dehydrated/rolled, etc., if necessary, so that the electrode of the present invention can be obtained again. A precursor can be obtained.

<Battery>
The present invention is also a battery constructed using the electrode of the present invention described above.
As described above, the battery of the present invention, which is configured by using the electrode of the present invention, can be sufficiently driven, can be easily manufactured, and has a high degree of freedom in assembly.

When the battery of the present invention is a battery including the electrode of the present invention as a zinc negative electrode having a zinc species as an active material, the positive electrode active material used is one usually used as the positive electrode active material of primary batteries or secondary batteries. It can be, but is not particularly limited, for example, oxygen (when oxygen becomes a positive electrode active material, the positive electrode is a perovskite type compound capable of reducing oxygen or oxidizing water, a cobalt-containing compound, an iron-containing compound, a copper-containing compound , An air electrode composed of a manganese-containing compound, a platinum-containing compound, and the like), nickel compounds such as nickel oxyhydroxide, nickel hydroxide, and cobalt-containing nickel hydroxide, and silver oxide. Among these, for example, the positive electrode active material is preferably a nickel compound.
It is also preferable that the positive electrode active material is oxygen. As described above, the active material layer included in the electrode of the present invention has a high degree of freedom during formation, such as being able to be formed by stacking electrode precursors that do not include a conductive member for current collection, and thus can be easily activated. The thickness of the substance layer can be increased. Therefore, the battery of the present invention is preferably a zinc-air battery in which it is required to increase the thickness of the negative electrode active material in order to increase the capacity. In other words, it is one of the preferred embodiments of the present invention that the battery of the present invention is a zinc-air battery.
In addition, as a form of a battery using the electrode of the present invention as a negative electrode, a primary battery, a rechargeable secondary battery, use of mechanical charge (mechanical replacement of zinc negative electrode), the negative electrode of the present invention are described above. Any form such as the use of a third pole different from the positive electrode composed of such a positive electrode active material may be used.

As the electrolytic solution used in the battery of the present invention, those usually used as an electrolytic solution of a storage battery can be used, and are not particularly limited, but for example, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, dimethoxy. Methane, diethoxymethane, dimethoxyethane, tetrahydrofuran, methyltetrahydrofuran, diethoxyethane, dimethylsulfoxide, sulfolane, acetonitrile, benzonitrile, ionic liquid, fluorine-containing carbonates, fluorine-containing ethers, polyethylene glycols, fluorine-containing polyethylene glycol And the like. The organic solvent-based electrolytic solution may be used alone or in combination of two or more. Examples of the aqueous electrolyte include potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, zinc sulfate aqueous solution, zinc nitrate aqueous solution, zinc phosphate aqueous solution, zinc acetate aqueous solution and the like. Among these, alkaline electrolytes such as potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, and lithium hydroxide aqueous solution are preferable. The water-based electrolytic solution may be used alone or in combination of two or more. The aqueous electrolytic solution may include the organic solvent electrolytic solution described above.

A separator may also be used as the battery of the present invention. The separator may be a member that separates the positive electrode from the negative electrode and holds the electrolytic solution to ensure ionic conductivity between the positive electrode and the negative electrode. The separator is not particularly limited, but non-woven fabrics, filter papers, polymers containing hydrocarbon moieties such as polyethylene and polypropylene, polymers containing polytetrafluoroethylene moieties, polymers containing polyvinylidene fluoride moieties, cellulose, fibrillated cellulose, viscose rayon, cellulose acetate. , Hydroxyalkyl cellulose, carboxymethyl cellulose, polyvinyl alcohol-containing polymer, cellophane, polystyrene-containing aromatic ring site-containing polymer, polyacrylonitrile site-containing polymer, polyacrylamide site-containing polymer, polyhalogenated vinyl site-containing polymer, polyamide site-containing polymer, polyimide Site-containing polymer, ester site-containing polymer such as nylon, poly(meth)acrylic acid site-containing polymer, poly(meth)acrylate site-containing polymer, hydroxyl group-containing polymer such as polyisoprenol or poly(meth)allyl alcohol, polycarbonate Carbonate group-containing polymer such as polyester, ester group-containing polymer such as polyester, carbamate or carbamide group-containing polymer such as polyurethane, agar, gel compound, organic-inorganic hybrid (composite) compound, ion exchange membrane polymer, cyclized polymer, sulfone Examples thereof include acid-containing polymers, quaternary ammonium salt-containing polymers, quaternary phosphonium salt polymers, cyclic hydrocarbon group-containing polymers, ether group-containing polymers, and inorganic materials such as ceramics. The separator may be one of these or two or more.

<Battery manufacturing method>
The present invention is also a method for producing a battery, wherein the method comprises placing an electrode precursor containing an active material and a polymer and having a solvent content of 0.1% by mass or less in contact with a current collector. Then, it is also a method of manufacturing a battery including a step of forming an electrode including a current collector and an active material layer, and a step of forming a battery using the electrode.

In the step of forming a battery using the above electrodes, a known method can be appropriately used as long as the contact between the active material and the current collector is maintained. For example, one or more electrode precursors of the present invention are superposed on a current collector, a separator and a positive electrode are superposed on it, and they are inserted into a battery cell of an appropriate size to bring the active material into contact with the current collector. A battery can be made by maintaining and introducing the electrolyte solution into the battery cell.
The steps of forming the electrode in the battery manufacturing method of the present invention are the same as those of the above-described electrode manufacturing method of the present invention.

The electrode precursor of the present invention has the above-mentioned structure and can be stored without being integrated with the current collector, so that it is not necessary to consistently perform from the preparation of the electrode precursor to the integration with the current collector. No equipment or resources are needed for that. Further, since the electrode precursor of the present invention is not integrated with the current collector, the current collector can be freely selected at the time of forming the electrode, and the electrode precursors can be superposed if necessary. As a result, various performances of the obtained electrode can be adjusted appropriately. Further, it is possible to easily cut into a desired size when forming the electrode, to easily remove an unnecessary portion, and it is possible to recycle the scraps and the like generated during the cutting of the electrode precursor as a battery precursor. The electrode precursor of the present invention is distributed only in the active material layer portion without being integrated with the current collector.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, "part" means "part by weight" and "%" means "% by mass" unless otherwise specified. The solvent content was measured by the above method.

(Example 1)
Polyolefin aqueous dispersion (Memii Chemical Co., Chemipearl S100), polytetrafluoroethylene and zinc oxide (average particle size 1 μm) were kneaded at a mass ratio of 1:3:96 and rolled while dehydrating through a nonwoven fabric. Then, it was completely dried in an oven at 60° C. to prepare an electrode precursor. The electrical resistance at this time was unmeasurable when a tester capable of measuring up to 1 MΩcm was used. The solvent content of this electrode precursor was 0.01 mass% or less, the thickness was 0.3 mm, and the ratio of the apparent density to the true density was 70%. The electrode precursor was placed on a punched steel plate plated with tin, a separator and a nickel positive electrode were superposed in that order, and then inserted into a battery cell. After that, the 8MKOH solution was introduced into the battery cell to form a nickel-zinc battery structure. When a charge/discharge test was attempted on this battery, a Coulomb efficiency of 99.8% was shown at a charge/discharge rate of 30 mA/cm ² , and it was observed that the battery was sufficiently driven.

(Example 2)
Polyolefin aqueous dispersion (Memii Chemical Co., Chemipearl S100), polytetrafluoroethylene and zinc oxide (average particle size 1 μm) were kneaded at a mass ratio of 1:3:96 and rolled while dehydrating through a nonwoven fabric. Then, it was completely dried in an oven at 60° C. to prepare an electrode precursor. The electrical resistance at this time was unmeasurable when a tester capable of measuring up to 1 MΩcm was used. The solvent content of this electrode precursor was 0.01 mass% or less, the thickness was 0.3 mm, and the ratio of the apparent density to the true density was 70%. At this time, the size of the electrode precursor (the area of the bottom surface in contact with the current collector) was 3 cm×3 cm, but the size of the battery cell (the area of the bottom surface in contact with the electrode precursor) was 2 cm×2 cm. The electrode precursor was cut so that the size of the electrode precursor matches the size of the battery cell. A similar electrode member could be obtained by crushing unnecessary members generated during this cutting, adding water and kneading again. When this was stacked on a current collector, a separator and a nickel positive electrode and driven as a battery, a Coulomb efficiency of 99.8% was exhibited, and the electrode precursor could be recycled.

(Example 3)
Polyolefin aqueous dispersion (Memii Chemical Co., Chemipearl S100), polytetrafluoroethylene and zinc oxide (average particle size 1 μm) were kneaded at a mass ratio of 1:3:96 and rolled while dehydrating through a nonwoven fabric. Then, it was completely dried in an oven at 60° C. to prepare an electrode precursor. The electrical resistance at this time was unmeasurable when a tester capable of measuring up to 1 MΩcm was used. The solvent content of this electrode precursor was 0.01 mass% or less, the thickness was 0.3 mm, and the ratio of the apparent density to the true density was 70%. The active material capacity at this time was 100 mAh/cm ² , but in order to obtain a larger capacity battery, three electrode precursors were stacked without using a binder or the like, and a current collector A separator and a nickel positive electrode were overlaid and inserted into a battery cell to form a battery. In order to confirm whether the capacity for three sheets could be driven, the battery was charged up to 250 mAh/cm ² and the discharge capacity was measured. As a result, the charged electricity quantity could be discharged with an efficiency of 99.8%.

The above examples relate to a zinc negative electrode and a nickel-zinc battery using the zinc negative electrode, and this is a preferred embodiment of the present invention. However, in other various electrodes and batteries, the electrode precursor according to the present invention is also used. It is understood that if the body is used, a battery having excellent charge/discharge characteristics can be easily manufactured, and the degree of freedom in forming electrodes is high. At least, if the electrode precursor according to the present invention is used to form an electrode, such as a zinc negative electrode, in which an active material is ionized and dissolved/precipitated when used in a battery, the degree of freedom in electrode formation is high. Further, it is understood that a battery having excellent charge/discharge characteristics can be easily manufactured.

Claims (2)

A method for producing an electrode including a current collector and an active material layer, comprising:
The method comprises a metal zinc simple substance and/or a zinc-containing compound as an active material and a polymer, and a solvent content of 0. 0 1 mass% or less arranged in the electrode precursor is shaped body in contact with the current collector to step constituting the electrode (however, the electrode precursor was placed in contact with the current collector by a roll method the Te excluding steps constituting the electrode) seen including,
The method for producing an electrode, wherein the polymer contains polyolefin and polytetrafluoroethylene . A method of manufacturing a battery, comprising:
The method comprises a metal zinc simple substance and/or a zinc-containing compound as an active material and a polymer, and a solvent content of 0. A step of arranging an electrode precursor, which is a molded body of 0.1% by mass or less , in contact with the current collector to form an electrode including the current collector and the active material layer (however, by a roll method (Excluding the step of arranging the electrode precursor so as to contact the current collector to form the electrode), and
Look including the step of a battery by using the electrode,
The method for producing a battery, wherein the polymer contains polyolefin and polytetrafluoroethylene .