JPH10188962A - Manufacture of sheetlike plate and nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a manufacture of a sheetlike plate as being capable of easily making electrode material extrusion coating faster and an application layer thinner and uniform and setting operation conditions to improve productivity and working efficiency in manufacturing the sheetlike plate. SOLUTION: In this method, electrode material coating liquid 12 is discharge from an extrusion liquid injector 7 with a slot nozzle 6 to be applied at a given thickness onto a running conductive support 1 wound on a backup roll 2. A depressurizing chamber 11 to put the running support 1 in a depressurized condition at the upstream side from the discharge port of the extrusion liquid injector 7 to its vicinity is provided to apply the coating liquid 12 thereon in the depressurized condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a sheet-like electrode and a non-aqueous electrolyte battery using the electrode plate.

[0002]

2. Description of the Related Art In a non-aqueous electrolyte battery, the electric conductivity of a non-aqueous electrolyte used is lower than that of an aqueous electrolyte battery. Therefore, it is necessary to reduce the thickness of an electrode layer formed on a conductive support as a current collector. is there. Among such nonaqueous electrolyte batteries, a cylindrical battery generally employs a spiral structure in which a sheet-like electrode is wound in order to increase the active material filling amount.

Conventionally, a roll rolling method has been used as a method for manufacturing a sheet-like electrode plate used as such an electrode. That is, the active material is kneaded with a conductive agent, a binder, and the like, and is roll-rolled and press-fitted into a support to form a sheet-shaped electrode plate. Also, a method of extruding the kneading mixture on both sides of the support (Japanese Patent Application Laid-Open No. 4-282558) and a pull-up method (Japanese Patent Application Laid-Open Nos. 62-256365 and 63-114).
058) and a lowering method (Japanese Patent Laid-Open Nos. 1-267953 and 1-194265) have also been proposed. These methods are efficient because they can be coated simultaneously on both sides, but have problems such as difficulty in locating the support at the center of the electrode sheet and making it impossible to prepare a thin coated layer sheet. on the other hand,
A roll coating method in which a plurality of rolls are combined and a coating solution is applied to a support by passing a coating liquid through a roll gap has been proposed as a method for manufacturing a sheet-shaped electrode plate.As an example, a reverse roll method, There is a gravure roll method and the like. However, in the case of these roll coat systems, there is a problem that a planar shape called living (undulation) or unevenness is observed, and it is difficult to smooth the sheet-shaped electrode plate. Further, a doctor blade method disclosed in JP-A-1-18469, JP-A-1-194265, JP-A-4-240207 and the like has been proposed as a method for manufacturing a thin sheet-shaped electrode plate. That is, the doctor blade is provided at an angle with a predetermined distance from the surface of the support to be coated. The conductive material is mixed with the active material, the binder is added, and the kneaded electrode material coating solution is stored inside the inclined doctor blade.The amount of the electrode material solution just before the running support is matched. Is drawn out in layers on the support to produce a sheet-like electrode plate.

Although it is possible to produce a thin sheet-shaped electrode plate by this doctor blade method, the solvent is evaporated during the application because the electrode material coating solution is applied while being stored inside the doctor blade. It is inevitable that the liquid concentration changes over time. The change in the concentration of the coating solution changes the physical properties of the coating solution and the amount of the active material to be applied, so that it is difficult to perform stable application. Further, in a doctor blade system as proposed in Japanese Patent Application Laid-Open No. H4-242071, since the coating liquid stored inside the doctor blade is continuously supplied onto the conductive support, the coating solution passing through the joint portion of the support may be used. In this case, it is necessary to finish applying the stored coating liquid before passing. Then, after passing through the joining portion, the supply of the application liquid is restarted again, but the original application width cannot be applied until the inside of the doctor blade is sufficiently filled with the application liquid. Therefore, there are problems that it is difficult to freely start and end the application, and it is not possible to simultaneously apply both surfaces.

By the way, as a method of applying an electrode material,
There is an extrusion method. The extrusion method is a method in which a coating liquid is supplied to a liquid injector, the coating liquid is discharged from a slot nozzle, and the liquid is coated on a running support. Further, since the coating liquid hardly comes into contact with the outside air until it is coated, the concentration of the coating liquid does not change due to evaporation of the solvent. Therefore, there is no need to adjust the coating thickness in accordance with the change in viscosity, so that stable coating can be performed as compared with the above-described respective coating methods, and there is a feature that there is little variation in product performance.

On the other hand, the production of the electrode material requires a large drying load after the application, and if the application of the electrode material is performed by running the support at a high speed, a large investment is required for the drying equipment. However, there is a strong demand for increasing the coating speed in order to reduce the production cost, and when using existing equipment, studies have been made to reduce the coating thickness by increasing the liquid concentration in order to reduce the drying load. However, since the electrode material coating liquid has a high viscosity and has a thixotropic property, the coating amount is reduced by coating using an extrusion type liquid injector,
It was difficult to increase the coating speed. That is, if the amount of the electrode material coating liquid supplied to the extrusion-type liquid injector is reduced in order to make the coating layer thinner, vertical streaks are generated in the conductive support running direction, or the streaks are not formed. (Application part) appears. Further, when the coating speed is increased while maintaining the coating thickness, vertical streaks and squeaks occur as in the case where the coating layer is thinned. Therefore, as a method for increasing the speed of application using an extrusion type liquid injector, a method of disposing a blade upstream of an inlet lip of a slot nozzle (Japanese Patent Laid-Open No. 1-180267) and a method of disposing a rotating roll upstream of an inlet lip are used. (Japanese Unexamined Patent Publication (Kokai) No. 1-180278) has been proposed, but in the blade arrangement method, it is difficult to set the position of the blade, and there is a case where the blade comes into contact with the support and cuts.
In addition, when a rotating roll is used, there has been a problem that the electrode material coating liquid adheres to the rotating roll at the time of application or the like and the coated surface shape is deteriorated.

[0007]

Accordingly, an object of the present invention is to increase the speed of extrusion coating of an electrode material, to make the coating layer thinner and more uniform, and to easily set operating conditions. An object of the present invention is to provide a method for manufacturing a sheet-like electrode plate, which can improve productivity and work efficiency. Another object of the present invention is to provide a non-aqueous electrolyte battery using a sheet-like electrode having such a thin coating layer.

[0008]

Means for Solving the Problems The inventors of the present invention have repeatedly conducted extensive research and trial manufacture on high-speed and thinning of electrode material using an extrusion type liquid injector having excellent coating stability and operating conditions. The present invention has been made. The object of the present invention is achieved by the following invention. That is, the present invention provides (1) a method of discharging an electrode material coating liquid from an extrusion type liquid injector having a slot nozzle and applying the electrode material coating liquid to a predetermined thickness on a conductive support which is wound around a backup roll and travels. Providing a decompression chamber for depressurizing an upstream portion (a feed side of the conductive support) of the running support in the vicinity thereof from the discharge port of the extrusion type liquid injector, and (2) A method for producing a sheet-shaped electrode plate, wherein (2) a tip end of a waste liquid port of an electrode material application liquid provided in the decompression chamber is water-sealed. A method for producing a sheet-like electrode plate according to
(3) The method for producing a sheet-shaped electrode plate according to (1), wherein the application condition of the electrode material application liquid by the extrusion type liquid injector satisfies the following mathematical formula 1.

(Equation 2) h: coating thickness (mm), d: distance between the tip of the slot and the conductive support (mm), μ: viscosity of the electrode material coating solution at the tip of the slot (mPas), L: width of the outlet side lip (m)
m), V: running speed (m / min) of the conductive support, P: decompression degree (mmH ₂ O) of the decompression chamber and (4) (1),
It is intended to provide a non-aqueous electrolyte battery using a sheet-like electrode produced by the method described in (2) or (3). The extrusion type liquid injector used in the present invention has a slot formed so that two lips face each other so as to keep close to each other, and has a liquid reservoir connected to the slot inside. The coating liquid is supplied to the liquid reservoir by a liquid supply facility provided outside the liquid injector, and is discharged from the slot nozzle through the communicating slot.
The slot nozzle is provided so as to keep an interval from the running conductive support, and the electrode material coating liquid discharged from the slot nozzle is applied in a layer on the conductive support.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an end view of an example of a coating apparatus used in the manufacturing method of the present invention, and a liquid injector is shown in a sectional view. In FIG. 1, 1 is a conductive support, 2 is a backup roll, 7 is an extrusion type liquid injector, and 11 is a decompression chamber. Here, the conductive support 1 is wound on the rotating backup roll 2 in close contact with the surface thereof and runs continuously.
The extrusion type liquid injector 7 is provided with the slot nozzle 6.
Is provided so as to keep a predetermined distance from the end face 6a of the support roll 1 and the support 1 on the backup roll 2. The extrusion type liquid injector 7 is provided with its slot nozzle 6 directed perpendicular to the outer peripheral surface of the backup roll. The slot nozzle 6 of the liquid injector 7 is formed by the inlet lip 3 and the outlet lip 4 with respect to the support 1, and the slot nozzle 6 has a structure communicating with the liquid reservoir 8 through the slot 5. The prepared electrode material coating liquid 12 is continuously supplied to a liquid injector 7 by a constant flow rate supply device (not shown) such as an appropriate constant flow rate pump, and is supplied from a liquid reservoir 8 through a slot 5 to a slot nozzle 6. The ink is discharged and applied on the conductive support 1 that runs continuously.

On the upstream side of the extrusion type liquid container 7, that is, on the side of the inlet lip 3, the decompression chamber 1 extends in the coating width direction.
1 is installed. The decompression chamber 11 is maintained at a predetermined decompression degree by constantly exhausting air from the exhaust port 10. During the coating, the pressure-reducing chamber covers the inlet-side lip together with the conductive support running around the backup roll, so that the pressure on the inlet-side lip is always maintained at a predetermined degree of reduced pressure. The decompression chamber is maintained in a decompressed state by sucking it from the exhaust port 10 with a vacuum pump, a blower, an aspirator, or the like. Since the inlet lip is maintained in a reduced pressure state, the meniscus 13 formed on the inlet lip during application of the electrode material application liquid is extremely stabilized as compared with when the pressure is not reduced. For this reason, it becomes possible to form a high-speed coating and a thin coating layer which cannot be realized under normal pressure.

When the electrode material is applied, the application may be interrupted without stopping the liquid supply for forming an uncoated portion or cleaning a slot. At this time, since the electrode material coating solution flows down and accumulates in the decompression chamber, the waste liquid port 16 is provided in the decompression chamber.
Is provided to discharge unnecessary coating liquid. When discharging the waste liquid, the tip of the waste liquid port is put into water 17 and constantly sealed with water in order to keep the degree of decompression in the decompression chamber constant. As described above, since the electrode material coating liquid has a high viscosity and has a thixotropic property, it is necessary to apply the electrode material coating liquid in order to achieve high-speed stabilization and thinning of the electrolyte material coating and stabilization of operating conditions. It is desirable to control conditions such as the viscosity of the liquid and the degree of decompression in the decompression chamber in correlation with the traveling speed of the support. Examination of the application conditions of the extrusion-type liquid injector revealed that the conditions represented by the following formula were preferable for stable application of the electrode material to the conductive support.

[0012]

(Equation 3)

FIG. 2 is an enlarged view mainly showing the slot nozzle 6 of the extrusion type liquid injector of FIG.
As shown in FIG. 2, h is the thickness of the coating film in the wet state (not including the thickness of the support), d is the distance between the tip 6a of the slot nozzle 6 and the conductive support, and μ is the tip of the slot. Of the electrode material coating liquid 12 in the portion (25
C), L is the width of the outlet lip, V is the running speed of the support,
P is each application condition of the degree of decompression in the decompression chamber. The coating thickness h in a wet state, the distance d between the tip 6a of the slot nozzle 6 and the conductive support, the unit of the width of the outlet lip is mm, the unit of the viscosity of the electrode material coating liquid is mPas, and the width of the outlet lip The unit of the cloth speed V is m / min, and the degree of reduced pressure P is mmH ₂ O. The viscosity of the electrode material coating liquid at the slot tip was determined by the following method. The viscosity of the electrode material coating liquid was measured at room temperature (25 ° C.) while changing the shear rate with a rheometer manufactured by Eology Co., Ltd. The shear stress is applied to the electrode material coating liquid at the slot tip, and the shear rate S is defined by the following equation.

[0014]

(Equation 4)

The unit of the shear rate S is sec ^-1 . The viscosity of the electrode material coating liquid at the shear rate at the tip of the slot nozzle determined from the above equation was determined from the measured value and used as the viscosity μ of the electrode material coating liquid at the tip of the slot nozzle.

As is clear from Equation 2, when it is desired to maintain the same coating film thickness by increasing the coating speed, it is effective to lower the viscosity of the electrode material coating solution as has been conventionally performed. It is effective to increase the degree of pressure reduction (to reduce the pressure further) or to narrow the width of the outlet side lip of the extrusion type liquid injector. Of course, the conditions can be selected by combining the viscosity of the electrode material application liquid, the degree of pressure reduction, and the like. In the coating method, the viscosity of the electrode material coating liquid is measured by a B-type viscometer (manufactured by Tokimec Co., Ltd.).
At 5 ° C., the range of 0.5 Pas to 300 Pas is good, preferably 0.6 Pas to 100 Pas, and more preferably 0.7 Pas to 50 Pas. The transport speed (running speed) of the conductive support in the present invention is not particularly limited, but is preferably 0.1 to 100 m / min, and particularly preferably 0.1 to 50 m / min.

The conductive support in the present invention is not particularly limited, but may be a metal foil (aluminum, copper, nickel, stainless steel, etc.), a conductive film of inorganic oxide, organic polymer material, carbon or the like. Can be used.
The form of the conductive support may be a continuous body, perforated, or a net, but a continuous body is particularly preferred. The thickness of the conductive support is
1 to 200 μm is preferred.

The present invention is applied to all batteries using a rectangular electrode or electrode sheet. As an example, a nonaqueous secondary battery using lithium as an active material will be described in detail below. Positive and negative electrodes used in the non-aqueous secondary battery of the present invention,
The positive electrode mixture or the negative electrode mixture can be applied on a current collector and molded. The positive electrode or negative electrode mixture may contain a conductive agent, a binder, a dispersant, a filler, an ionic conductive agent, a pressure enhancer, and various additives, respectively, in addition to the positive electrode active material or the negative electrode material.

The active material in the positive electrode that can be used in the present invention may be any material capable of inserting and releasing a light metal, but is preferably a lithium-containing transition metal oxide, and more preferably L-containing transition metal oxide.
_{i x CoO 2, Li x NiO} 2, Li x Co a Ni 1-a
O ₂ , Li _x Co _b V _1-b O _z , Li _x Co _b Fe _1-b
O _z , Li _x Mn ₂ O ₄ , Li _x MnO ₂ , Li _x Mn
₂ O ₃ , Li _x Mn _b Co _2-b O _z , Li _x Mn _b Ni
_{2-b Oz} , Li _x Mn _b V _2-b O _z , Li _x Mn _b Fe
_1-b O _z (where x = 0.05 to 1.2, a = 0.1 to
0.9, b = 0.8 to 0.98, z = 1.5 to 5). Hereinafter, the light metal referred to in the present invention is an element belonging to Group 1A (excluding hydrogen) and Group 2A of the periodic table, preferably lithium, sodium, and potassium, and particularly preferably lithium.

The active material in the negative electrode that can be used in the present invention is not particularly limited as long as it can insert and emit light metals, and is preferably graphite (natural graphite, artificial graphite, vapor-grown graphite), coke (coal or petroleum). Baked organic polymer (resin or fiber of polyacrylonitrile, furan resin, cresol resin, phenol resin), mesophase pitch baked product, metal oxide, metal chalcogenide, lithium-containing transition metal oxide and chalcogenide. In particular, Ge,
Oxides and chalcogenides composed of Sn, Pb, Bi, Al, Ga, Si and Sb alone or in combination thereof are preferred. Furthermore, SiO ₂ , B ₂ O ₃ , P ₂ O ₅ , Al ₂ O ₃ , V
Those made amorphous by adding ₂ O ₅ or the like are particularly preferable. These may be of stoichiometric composition or non-stoichiometric compounds. Preferred examples of these compounds include the following, but the present invention is not limited thereto.

GeO, GeO ₂ , SnO, SnO ₂ , S
nSiO ₃ , PbO, SiO, Sb ₂ O ₅ , Bi ₂ O
₃ , Li ₂ SiO ₃ , Li ₄ Si ₂ O ₇ , Li ₂ GeO
_{3, SnAl 0.4 B 0.5 P 0.5} K 0.1 O 3.65, SnAl
_0.4 B _0.5 P _0.5 Cs _0.1 O _3.65 , SnAl _0.4 B _{0.5
P 0.5 K 0.1 Ge 0.05 O 3.85} , SnAl 0.4 B 0.5 P
_0.5 K _0.1 Mg _0.1 Ge _0.02 O _3.83 , SnAl _0.4 B
_0.4 P _0.4 Ba _0.08 O _3.28 , SnAl _0.5 B _0.4 P _0.5
Mg _0.1 F _0.2 O _3.65 , SnAl _0.4 B _0.5 P _0.5 Cs
_0.1 Mg _0.1 F _0.2 O _3.65 , SnB _0.5 P _0.5 Cs _0.05
Mg _0.05 F _0.1 O _3.03 , Sn _1.1 Al _0.4 B _0.4 P _0.4
Ba _0.08 O _3.34 , Sn _1.2 Al _0.5 B _0.3 P _0.4 Cs
_0.2 O _3.5 , SnSi _0.5 Al _0.2 B _0.1 P _0.1 Mg
_0.1 O _2.8 , SnSi _0.5 Al _0.3 B _0.4 P _0.5
O _4.30 , SnSi _0.6 Al _0.1 B _0.1 P _0.1 Ba _0.2 O
_2.95 , SnSi _0.6 Al _0.4 B _0.2 Mg _0.1 O _3.2 , S
_{n 0.9 Mn 0.3 B 0 .4 P} 0.4 Ca 0.1 Rb 0.1 O 2.95,
Sn _0.9 Fe _0.3 B _0.4 P _0.4 Ca _0.1 Rb _0.1
O _2.95 , Sn _0.3 Ge _0.7 Ba _0.1 P _0.9 O _3.35 , Sn
_0.9 Mn _0.1 Mg _0.1 P _0.9 O _3.35 , Sn _0.2 Mn _0.8
Mg _0.1 P _0.9 O _3.35 .

Further, the negative electrode material of the present invention can be used by inserting a light metal, particularly lithium. The method of inserting lithium is preferably an electrochemical, chemical or thermal method.

The amount of lithium inserted into the negative electrode material of the present invention is:
It may be up to approximation of the deposition potential of lithium, but is preferably 50 to 700 mol% per the above-mentioned preferable negative electrode material.
Particularly, 100 to 600 mol% is preferable.

The conductive agent in the positive electrode and the negative electrode that can be used in the present invention is graphite, acetylene black, carbon black, Ketjen black, carbon fiber or metal powder, metal fiber or polyphenylene derivative, and particularly preferably graphite and acetylene black. . The binder in the positive electrode and the negative electrode that can be used in the present invention is polyacrylic acid, carboxymethylcellulose, polytetrafluoroethylene,
Polyvinylidene fluoride, polyvinyl alcohol, starch,
Regenerated cellulose, diacetyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone, polyethylene, polypropylene, SBR, E
PDM, sulfonated EPDM, fluororubber, polybutadiene, and polyethylene oxide, with polyacrylic acid, carboxymethylcellulose, polytetrafluoroethylene, and polyvinylidene fluoride being particularly preferred. These are more preferably used as an aqueous dispersion latex having a particle size of 1 micron or less.

The conductive supports or current collectors of the positive electrode and the negative electrode that can be used in the present invention are made of aluminum, stainless steel, nickel, titanium, or an alloy thereof for the positive electrode, and copper or stainless steel for the negative electrode. Steel, nickel, titanium, or alloys of these, in the form of foil,
Expanded metal, punching metal, wire mesh.
In particular, an aluminum foil is preferable for the positive electrode, and a copper foil is preferable for the negative electrode. The separator that can be used in the present invention has a high ion permeability, a predetermined mechanical strength, and may be an insulating thin film. As the material, olefin polymer, fluorine polymer, cellulose polymer, polyimide, nylon, Glass fibers and alumina fibers are used, and as a form, a nonwoven fabric, a woven fabric, or a microporous film is used. In particular, the material is preferably polypropylene, polyethylene, a mixture of polypropylene and polyethylene, a mixture of polypropylene and Teflon, a mixture of polyethylene and Teflon, and the form is preferably a microporous film. In particular, the pore size is 0.01 to 1 μm and the thickness is 5 to 50.
μm microporous films are preferred.

The electrolytic solution that can be used in the present invention includes propylene carbonate, ethylene carbonate,
Butylene carbonate, dimethyl carbonate, diethyl carbonate, 1,2-dimethoxyethane, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylsulfoxide, dioxolan,
1,3-dioxolan, formamide, dimethylformamide, nitromethane, acetonitrile, methyl formate,
Methyl acetate, methyl propionate, phosphoric acid triester,
Trimethoxy methane, dioxolane derivatives, sulfolane, 3-methyl-2-oxazolidinone, propylene carbonate derivatives, tetrahydro derivative, diethyl ether, as a mixture of at least one or more kinds of 1,3-propane sultone, and as the electrolyte, LiClO ₄ , L
iBF ₄ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF _{3
CO 2, LiAsF 6, LiSbF 6} , LiB 10 C
l ₁₀ , lithium lower aliphatic carboxylate, LiAlCl
₄ , a solution in which one or more salts of LiCl, LiBr, LiI, lithium chloroborane, and lithium tetraphenylborate are dissolved. In particular, a mixed solvent of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate
It is preferable to dissolve CF ₃ SO ₃ , LiClO ₄ , LiBF ₄ , and / or LiPF ₆ , and it is particularly preferable to contain at least ethylene carbonate and LiPF ₆ .

The shape of the battery can be applied to both cylinders and corners. In this case, the electrode is used by applying the mixture on the current collector, drying, dehydrating, and pressing. A battery is formed by inserting an electrode wound with a separator into a battery can, electrically connecting the can and the electrode, injecting an electrolyte, and sealing the battery. At this time, the safety valve can be used as a battery lid. Further, it is preferable to use a PTC element in order to guarantee the safety of the battery.

The bottomed battery outer can that can be used in the present invention is made of a nickel-plated iron steel plate or stainless steel plate (SUS304, SUS304L, SUS304).
N, SUS316, SUS316L, SUS430, S
US444, etc.), nickel-plated stainless steel plate (same as above), aluminum or its alloy, nickel,
They are titanium and copper, and have a shape of a perfect circular cylinder, an elliptical cylinder, a square cylinder, or a rectangular cylinder. In particular, when the outer can also serves as the negative electrode terminal, a stainless steel plate or a nickel-plated iron steel plate is preferable, and when the outer can also serves as the positive electrode terminal, a stainless steel plate, aluminum or an alloy thereof is preferable.

The gaskets usable in the present invention are olefin polymers, fluorine polymers, cellulose polymers, polyimides and polyamides, and olefin polymers are preferred from the viewpoint of organic solvent resistance and low moisture permeability. Propylene-based polymers are preferred. Further, it is preferably a block copolymer of propylene and ethylene.

[0030] The battery of the present invention is covered with an exterior material if necessary. Examples of the exterior material include a heat-shrinkable tube, an adhesive tape, a metal film, paper, cloth, paint, a plastic case, and the like. Further, at least a part of the exterior may be provided with a portion that changes color by heat so that the heat history during use can be recognized. The battery of the present invention is assembled in a battery pack in a plural number in series and / or parallel as required. In addition to safety elements such as positive temperature coefficient resistors, thermal fuses, fuses and / or current interrupting elements, battery packs have safety circuits (voltage, temperature, current, etc. of each battery and / or assembled battery as a whole, Then, a circuit having a function of interrupting the current may be provided. In addition to the positive and negative terminals of the whole battery pack, the positive and negative terminals of each battery, the temperature detection terminals of the whole battery pack and each battery, the current detection terminals of the whole battery pack, etc. shall be provided as external terminals on the battery pack. Can also. The battery pack may have a built-in voltage conversion circuit (such as a DC-DC converter). The connection of each battery may be fixed by welding a lead plate, or may be fixed by a socket or the like so that it can be easily detached. Further, the battery pack may be provided with a display function of the remaining battery capacity, the presence or absence of charging, the number of times of use, and the like.

The battery of the present invention is used for various devices.
In particular, video movies, portable VCRs with built-in monitors, movie cameras with built-in monitors, compact cameras,
SLR camera, disposable camera, film with lens, notebook computer, notebook word processor, electronic organizer,
It is preferably used for mobile phones, cordless phones, razors, electric tools, electric mixers, automobiles and the like.

A general type of mixing and dispersing apparatus is used for preparing an electrode material coating solution, that is, a coating solution of an electrode mixture. For example, a horizontal cylindrical mixer, a V-shaped mixer, a double conical mixer, a paddle-shaped mixer,
Ribbon mixers, planetary mixers, screw mixers, high-speed flow mixers, horizontal single-axis mixers, horizontal double-axis mixers, vertical-axis mixers, and the like are used. Specifically, vertical ribbon mixers, horizontal ribbon mixers, vertical screw mixers, horizontal screw mixers, ball mills, pin mixers, double-armed kneaders, pressure kneaders, sand grinders, universal mixers, cutters, cutters Although a mixer etc. are mentioned, it is not limited to this. Of course, the mixing and dispersing devices can be implemented alone or in combination.

When the shape of the battery is a sheet, a cylinder, or a corner, the prepared electrode mixture is applied onto a current collector, dried, and compressed, and is mainly used. The thickness, length and width of the coating layer of the coated sheet-like electrode are determined by the size of the battery, and the thickness of the coating layer is 1 in the compressed state after drying.
２０００2000 μm is particularly preferred. The tension acting on the conductive support (current collector) is not particularly limited.
g / cm to 2000 g / cm is preferable, and especially 20 g / cm
cm to 1000 g / cm is preferred. In addition, when the traveling position fluctuates, the support is EPC (edge position
Controller) and the like.

The conductive support on which the electrode mixture has been applied is transported to a drying chamber where the solvent is removed. The drying method is not particularly limited and a general method can be used.Hot air, vacuum, infrared ray, far infrared ray, contact drum method, microwave, low humidity wind, induction heating or the like alone or It can be implemented in combination. The drying temperature is preferably from 20C to 350C, particularly preferably from 40C to 200C.
C is preferred. The tension is appropriately selected depending on the proof stress, flapping, curling, wrinkling, etc. of the support.
00 g / cm is preferred, and especially 20 g / cm to 1000
g / cm is preferred.

The mixture applied to the conductive support is dried and then pressed. As a pressing method, a generally used method can be used, but a roller pressing method is particularly preferable. Press roller diameter is 100mm or more 3
000 mm or less, and the pressing pressure is 200 kg /
cm ^{2 to} 10,000 kg / cm ² is preferable. The pressing speed is preferably from 0.1 m / min to 50 m / min. The pressing temperature is preferably from room temperature to 200 ° C. The tension is appropriately selected depending on the proof stress, flapping, curling, wrinkling, etc. of the support.
/ Cm to 2000 g / cm is preferable, and especially 20 g / c
m to 1000 g / cm is preferred.

In the case where water remains in the mixture, a dehydration step is performed as necessary to remove the water. As a method of dehydration, a normal method is used.
Vacuum, infrared, far infrared, microwave, low humidity wind, induction heating, electron beam, etc. can be used alone or in combination. The drying temperature is preferably in the range of 20C to 350C, particularly preferably 100C to 250C. The water content is preferably 2,000 ppm or less in the whole battery, and is preferably 500 ppm or less in the electrode mixture.
ppm or less is more preferable.

The electrode sheet is used after being cut into a required shape. As a cutting method, a conventional shearing method, a precision punching method, a shearing method without burrs, a flat pushing method, a vertical punching method, a punching method with a burrs and the like are used. Cutting is tension 10g / cm-2000
g / cm, particularly 20 g / cm to 1000 g / cm.
cm is preferred. The tension is appropriately selected depending on the strength of the support, flapping, curling, wrinkling, width accuracy of the electrode, and the like.

[0038]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention. The viscosity in the examples is 25.
It is a value at ° C.

Example 1 LiCoO as a positive electrode active material
₂ 87 parts by weight, were mixed in a ratio of graphite 9 parts by weight as a conductive agent, further polytetrafluoroethylene 3 parts by weight of sodium polyacrylate 1 parts by weight was added as a binder, with the addition of water as a solvent, The mixture was kneaded and dispersed using a universal mixer having a rotating stirrer and a universal mixer having a stirring blade that rotates while rotating, thereby preparing a slurry of a positive electrode material coating solution. This coating solution was applied on a support. As shown in FIG. 3, the coating machine is a winding / unwinding unit that unwinds the unwinding roll 14 of the support 1, the backup roll 2, and the application unit 15 including the coating device 15, the drying chamber 18, and the coated electrode sheet 20. In order to perform double-sided coating, one side (surface) of the conductive support is coated, dried and wound up, and then re-attached to the delivery. Apply the opposite side (back side). An aluminum foil having a thickness of 30 μm was used as a conductive support. As the coating device 15, a device as shown in FIGS. 1 and 2 is used.
The distance d between the tip 6a of the slot nozzle 6 and the conductive support is 0.5 mm, the slot clearance c is 0.5 mm, the width of the inlet and outlet lips is 1 mm, and the inner diameter of the liquid reservoir is 50 m.
m, conveying speed: 5 m / min, coating width: 0.5 m, decompression degree: 40 mmH ₂ O, electrode material coating liquid coating thickness h: 0.1
5 mm. The solid content of the electrode material coating solution is 65
In weight percent, the apparent viscosity was 5 Pas and the viscosity at the slot tip was 543 mPas. The drying room consists of 4 rooms, each room is hot air drying by slit method with 8% opening ratio.
/ Sec, the third room and the fourth room have a temperature of 50 ° C. and a slit wind speed of 6
Drying was performed under the conditions of m / sec. The drying air supplied to each room was controlled at a dew point of 9 ° C.

Example 2 SiSnO as negative electrode active material
₃ 86 parts by weight, were mixed at a ratio of 3 parts by weight of acetylene black and 6 parts by weight of graphite as a conductive agent, additional 4 parts by weight polyvinylidene fluoride and 1 part by weight of carboxymethyl cellulose was added as a binder, adding water as a solvent The mixture was kneaded and dispersed using a dispersing apparatus having the same system as in Example 1 to prepare a negative electrode material coating liquid. The solid content of the electrode material coating liquid was 48% by weight, and the apparent viscosity was 2.0 Pa.
s.

A 20 μm-thick copper foil was coated on both sides one by one using the same method and apparatus as in the positive electrode of Example 1. The inner diameter of the liquid reservoir is 50 mm, the coating width is 500 mm, the distance d between the slot tip and the conductive support is 0.4 mm, the slot clearance c is 0.5 mm, and the width of the inlet and outlet lip surfaces is 1 m.
m, the transport speed is 1 m / min, the degree of pressure reduction is 40 mmH ₂ O,
Coating thickness 0.08mm, viscosity of slot tip 560m
Pas. Drying was performed under the conditions of the first and second chambers at 50 ° C. and a slit air velocity of 3 m / sec, and the third and fourth chambers were performed at 60 ° C. and a slit air velocity of 10 m / sec. The temperature was controlled at 8 ° C.

Example 3 The negative electrode material coating solution of Example 2 was used, and a coating speed of 5 m / mi was selected from the coating conditions of Example 2.
n, degree of pressure reduction 100 mmH ₂ O, viscosity 2 at the end of the slot wire
The application was changed to 94 mPas.

Example 4 SnO 8 as a negative electrode active material
6 parts by weight, 3 parts by weight of acetylene black as a conductive agent and 6 parts by weight of graphite were mixed, 4 parts by weight of polyvinylidene fluoride and 1 part by weight of carboxymethyl cellulose were added as a binder, and water was added as a solvent. Using the same dispersing apparatus as in Example 1, the mixture was kneaded and dispersed to prepare a negative electrode material coating liquid. The solid content of the electrode material coating liquid was 45% by weight, and the apparent viscosity was 1.5 Pas.
Coating was performed in the same manner as in the negative electrode of Example 1. Liquid reservoir inner diameter 50m
m, inner diameter 50 mm, coating width 500 mm, distance d between slot nozzle and conductive support 0.4 mm, slot clearance c 0.5 mm, inlet lip width 1 mm, outlet lip width 0.5 mm, transport Speed is 5m / min,
The coating was performed with a coating thickness of 0.1 mm, a reduced pressure of 25 mmH ₂ O, and a viscosity of 236 mPas at the tip of the slot.

Example 5 Using the negative electrode material coating solution of Example 4, coating was performed in exactly the same manner as in Example 4 except that the degree of pressure reduction was changed to 80 mmH ₂ O. [Example 6] The coating thickness of the coating material of Example 1 was changed to 0.38 mm and the distance d between the end of the slot and the conductive support was changed to 0.8 mm using the coating solution of the positive electrode material of Example 1. Application was performed.

[Comparative Example 1] Using the positive electrode material coating solution of Example 1, coating was performed in exactly the same manner as in Example 1 except that the pressure was reduced to 0 mmH ₂ O.

Comparative Example 2 Using the coating solution for the positive electrode material of Example 1, coating was performed in exactly the same manner as in Example 1 except that the reduced pressure was changed to 20 mmH ₂ O.

[0047] [Comparative Example 3] the negative-electrode material coating solution of Example 2, the degree of vacuum 0 mm H ₂ O of the coating conditions, coating speed 1
m / min, viscosity of the coating liquid at the end of the slot is 560 mP
Coating was performed in exactly the same manner as in Example 2 except that the coating was changed to as.

COMPARATIVE EXAMPLE 4 Using the negative electrode material coating liquid of Example 2, the application conditions were a pressure reduction of 40 mmH ₂ O, a coating speed of 5 m / min, and a coating liquid viscosity of 294 m at the slot tip.
Coating was carried out in exactly the same manner as in Example 2 except that Pas was changed.

Comparative Example 5 Using the negative electrode material coating solution of Example 4, coating was performed in the same manner as in Example 4 except that the application conditions were changed to a reduced pressure of 10 mmH ₂ O.

The surface of the sheet-like electrode (smoothness and generation of streaks) obtained by applying the electrode material according to the above Examples and Comparative Examples was observed. The results are shown in Table 1. As is evident from the results in Table 1, a coating chamber is provided upstream of the extrusion type liquid injector, and the vicinity of the inlet side lip is maintained in a reduced pressure state, so that the coating speed is greatly increased as compared with the case where no vacuum chamber is provided. Even with this method, it is possible to perform good coating without any vertical streaks or missing streaks.

[0051]

[Table 1]

As is clear from the comparison of the surface conditions with the application conditions of the examples and comparative examples, the application conditions for suppressing the occurrence of vertical streaks and streaks and performing stable application are always the values on the left side of the expression (1). Is larger than the right side, and it can be seen that Expression 1 is satisfied. The coating conditions under which vertical streaks and missing streaks occur do not fall within the range of Expression 1.

[0053]

According to the method of the present invention, stable coating can be performed even under conditions where the coating thickness of the electrode material is small and the coating speed is high, and since the coating can be performed stably, the variation in product performance is remarkably reduced. Can be reduced. Further, according to the present invention, it is possible to easily and quickly set the electrode material application conditions. According to the present invention, the production speed of the sheet-like electrode is greatly increased, and the production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is an end view showing a main part of a coating apparatus used for carrying out the present invention, and a liquid injector is shown in a cross section.

FIG. 2 is a partial cross-sectional view showing an enlarged part of a main part of the coating apparatus of FIG. 1;

FIG. 3 is a flowchart showing the whole process of manufacturing a sheet-like electrode according to the embodiment of the present invention.

[Description of Signs] 1 conductive support 2 backup roll 3 inlet lip 4 outlet lip 5 slot 6 slot nozzle 7 extrusion type liquid injector 8 liquid reservoir 9 slot inlet 10 exhaust port 11 decompression chamber 12 coating liquid 13 meniscus 14 Unwinding roll 15 Coating device 16 Waste liquid port 17 Water 18 Drying chamber 19 Winding roll 20 Electrode sheet L Exit lip width d Distance between conductive support and slot nozzle tip h Coating thickness c Slot clearance

Claims (4)

[Claims] An extrusion type liquid injector having a slot nozzle discharges an electrode material application liquid and applies the electrode material to a predetermined thickness on a conductive support running around a backup roll. A sheet-shaped sheet is provided, in which a decompression chamber is provided from the discharge port of the mold injecting device to decompress an upstream portion of the running support in the vicinity thereof in a decompressed state, and the coating liquid is applied under reduced pressure. Manufacturing method of electrode plate. 2. The method for manufacturing a sheet-like electrode plate according to claim 1, wherein a tip end of a waste liquid port of the electrode material application liquid provided in the decompression chamber is sealed with water. 3. The method for producing a sheet-shaped electrode plate according to claim 1, wherein the application condition of the electrode material application liquid by the extrusion type liquid injector satisfies the following mathematical expression 1. (Equation 1) h: coating thickness (mm), d: distance between the tip of the slot and the conductive support (mm), μ: viscosity of the electrode material coating solution at the tip of the slot (mPas), L: width of the outlet side lip (m)
m), V: traveling speed of the conductive support (m / min), P: degree of decompression of the decompression chamber (mmH ₂ O) 4. A non-aqueous electrolyte battery using a sheet-like electrode produced by the method according to claim 1.