JP5698044B2 - Battery electrode manufacturing method and battery electrode manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing a battery electrode such as a lithium ion secondary battery having a solid electrolyte layer interposed between active material layers, and a battery electrode manufacturing apparatus.

  Lithium ion secondary batteries composed of positive electrodes, negative electrodes, electrolytes (solid electrolytes), separators, etc. are lightweight, large-capacity, and capable of high-speed charge / discharge. However, various researches have been made to further increase the capacity and charge / discharge at high speed.

  The reaction between the positive electrode active material and the negative electrode active material contained in the positive electrode and the negative electrode, respectively, and the electrolyte is rate-limiting, but the lithium ion conductivity of the electrolyte is low. Therefore, in order to increase the capacity and charge / discharge at high speed, the gap between the positive electrode and the negative electrode should be as narrow as possible and the electrode area of the positive electrode and the negative electrode should be as large as possible. It is important to increase the contact area.

  Focusing on this point, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2006-147210) provides a solid electrolyte secondary battery structure that realizes low cost, high safety, high energy density, and high output. The intended technology has been proposed.

  That is, in the above-mentioned Patent Document 1, a positive electrode current collector and a negative electrode current collector are patterned on a substrate having a flat surface in a comb-like shape facing each other, and a positive electrode ( By patterning the particles of the positive electrode active material in the present invention material and the negative electrode (negative electrode active material in the present invention) material in the direction perpendicular to the current collector surface by electrophotography, a vertical electrode is formed. A planar comb-shaped secondary battery configuration in which a gap formed between positive and negative electrodes is filled with a solid electrolyte has been proposed (see Patent Document 1, Abstract, etc.).

JP 2006-147210 A

  However, in the technique proposed in the above-mentioned Patent Document 1, the pattern of the electrode material (that is, the active material) after coating is expressed by “heating (temperature of about 150 to 250 ° C.) or solvent (methanol, acetone, acetonitrile). And the like, and then it is melted, evaporated and solidified. "(Patent Document 1, paragraph [0023]).

  In such a method, the shape of the pattern after coating is lost due to a shock caused by heat or a state change caused by addition of a solvent, and it is difficult to form a high active material layer with a high aspect ratio. Inferior performance. Further, the latter method of supplying the solvent takes time for evaporation and solidification, and is inferior in economic efficiency and productivity. Furthermore, the electrophotographic method used in Patent Document 1 is a transfer process using a transfer plate, and it is necessary to charge the transfer plate, which causes a problem that the process and apparatus configuration become complicated. .

  In view of the above problems, it is an object of the present invention to form a thick active material layer with a high aspect ratio with a simpler process and apparatus configuration than in the prior art, and to provide a lithium ion secondary battery excellent in charge / discharge capacity. It aims at providing the technique for obtaining the electrode for batteries for implement | achieving batteries, such as a secondary battery.

In order to solve the above problems, the present inventors have
An application step of forming a linear active material pattern on the current collector by moving a nozzle for discharging the paste-like active material material in a linear shape relative to the current collector;
A first drying step of drying the active material pattern at a first drying temperature within a range of 5 ° C to 50 ° C ;
A second drying step of drying the active material pattern after the first drying step at a second drying temperature within a range of 70 ° C. to 150 ° C. higher than the first drying temperature;
Only including,
In the coating step, the active material is a mixture containing at least an active material powder and a solvent, and the mixture has a solid content ratio smaller than a solid content ratio at a wet point of the mixture,
In the first drying step, the solvent in the active material pattern is vaporized and discharged out of the active material pattern until the solid content ratio of the active material pattern becomes equal to the solid content ratio at the wet point of the mixture. ,
Forming an active material pattern having an aspect ratio of 0.4 or more on the current collector;
The manufacturing method of the electrode for batteries characterized by these is provided.

According to the method for manufacturing a battery electrode of the present invention having such a configuration , the active material pattern formed by the coating process is dried in two stages, so that the thickness and thickness of the active material pattern can be increased without damaging the shape and dimensions of the active material pattern. An active material layer of the film can be formed, and a battery electrode for realizing a battery such as a lithium ion secondary battery excellent in charge / discharge capacity can be obtained.

In addition, according to such a configuration, when the active material pattern formed by the coating process is dried in two stages, the active material having a high aspect ratio and a thick film can be more reliably lost without losing the shape and dimensions of the active material pattern. A battery electrode for realizing a battery such as a lithium ion secondary battery having excellent charge / discharge capacity can be obtained.

  Here, the “wetting point” refers to a point where the whole becomes wet when the solvent is gradually added to the mixture of the components of the active material excluding the solvent while kneading. In the measurement of the “wet point”, the solvent is dropped little by little with a burette into a mixture (powder) of the components of the active material excluding the solvent and kneaded with a spatula. When the solvent is added dropwise and kneaded while being added, the amount of the mixture that can be formed into a lump like the dumpling is reached. Thus, the minimum amount of solvent required to obtain a mass is called the “wet point”. The solid content ratio at the wet point varies depending on the composition of the active material, but the range is approximately 50 to 80% by mass.

The present invention also provides:
A nozzle that discharges a paste-like active material in a line;
Scanning means for moving the nozzle relative to the current collector to form a linear active material pattern on the current collector;
Drying means for drying the active material pattern formed on the current collector;
The active material pattern is dried at a first drying temperature within a range of 5 ° C. to 50 ° C. , and then dried at a second drying temperature within a range of 70 ° C. to 150 ° C. higher than the first drying temperature. Control means for controlling the drying means;
Only including,
The active material is a mixture containing at least an active material powder and a solvent, and the mixture has a solid content ratio smaller than a solid content ratio at a wet point of the mixture,
The control means dries the active material pattern at a first drying temperature until the solid content ratio of the active material pattern becomes equal to the solid content ratio at the wet point of the mixture, and the solvent in the active material pattern Vaporizing and discharging out of the active material pattern,
The aspect ratio of the active material pattern on the current collector is 0.4 or more,
A battery electrode manufacturing apparatus is provided.

According to the battery electrode manufacturing apparatus of the present invention having such a configuration, a linear active material pattern can be formed, and the active material pattern can be dried in two stages. Thus, a thick active material layer can be formed with a high aspect ratio without impairing the dimensions, and a battery electrode for realizing a battery such as a lithium ion secondary battery having excellent charge / discharge capacity can be obtained.

In addition, according to such a configuration, when the active material pattern is dried in two stages, the solid content ratio in the active material pattern can be controlled, and the shape and dimensions of the active material pattern can be more reliably impaired. Thus, a thick active material layer can be formed with a high aspect ratio, and a battery electrode for realizing a battery such as a lithium ion secondary battery excellent in charge / discharge capacity can be obtained.

  According to the present invention, a battery such as a lithium ion secondary battery that can form an active material layer having a high aspect ratio and a high height with a simpler process and device configuration than the conventional one, and is excellent in charge / discharge capacity. A technique for obtaining a battery electrode to be realized can be provided.

It is a schematic longitudinal cross-sectional view of the lithium ion secondary battery manufactured in one Embodiment of this invention. 1 is a schematic perspective view of a structure (negative electrode) 20 in which a negative electrode active material layer pattern 12A composed of a negative electrode active material layer 12 is formed on the surface of a negative electrode current collector 10 in an embodiment of the present invention. It is a figure which shows the structure of the negative electrode manufacturing apparatus in one Embodiment of this invention. It is a schematic diagram which shows a mode that the negative electrode active material layer pattern 12A which consists of the negative electrode active material layer 12 is formed by the nozzle dispensing method in one Embodiment of this invention. It is a figure which shows typically a mode that a solid electrolyte layer is formed using the spin coat method in one Embodiment of this invention. It is a figure which shows typically a mode that a positive electrode active material layer is formed using a doctor blade method. It is a figure which shows the structure of the negative electrode manufacturing apparatus in another embodiment of this invention. It is a schematic longitudinal cross-sectional view of the lithium ion secondary battery manufactured in the modification of this invention. It is a graph which shows the aspect-ratio etc. of the positive electrode active material layer formed in Example 1 of this invention. It is a graph which shows the aspect-ratio etc. of the positive electrode active material layer formed in the comparative example 1 of this invention. It is a graph which shows the measurement result of the solid content ratio of the positive electrode active material layer formed in Example 1 of this invention. It is a graph which shows the aspect-ratio etc. of the negative electrode active material layer formed in Example 2 of this invention. It is a graph which shows the aspect-ratio etc. of the negative electrode active material layer formed in the comparative example 2 of this invention. It is a graph which shows the measurement result of the solid content ratio of the negative electrode active material layer formed in Example 2 of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a battery electrode manufacturing method and a battery electrode manufacturing apparatus according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description may be omitted. Moreover, since the drawings are for conceptual description of the present invention, the dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

Embodiment 1
(1) Structure of Lithium Ion Secondary Battery In the present embodiment, the present invention will be described in the case of manufacturing a lithium ion secondary battery having the structure shown in FIG. FIG. 1 is a schematic longitudinal sectional view of a lithium ion secondary battery 1 manufactured in the present embodiment. 2 shows a structure obtained when the negative electrode active material layer 12 is formed on the surface of the negative electrode current collector 10 (that is, formed on the surface of the negative electrode current collector 10 and the negative electrode current collector 10). 1 is a perspective view showing a negative electrode 20 including a negative electrode active material layer 12.

  The lithium ion secondary battery 1 of this embodiment has a structure in which a negative electrode active material layer 12, a solid electrolyte layer 14, a positive electrode active material layer 16, and a positive electrode current collector 18 are laminated in this order on a negative electrode current collector 10. Have. The negative electrode current collector 10 and the negative electrode active material layer 12 constitute a negative electrode, and the positive electrode active material layer 16 and the positive electrode current collector 18 constitute a positive electrode. In this specification, the X, Y, and Z coordinate directions are defined as shown in FIGS.

  As the negative electrode current collector 10, a known material in the technical field to which the present invention belongs can be used, but a metal film such as an aluminum foil or a copper foil may be used. Although not shown, the negative electrode current collector 10 may be formed on the surface of an insulating base material. As such a base material, a flat plate member made of an insulating material may be used. Examples of such an insulating material include resin, glass, ceramics, and the like. The base material may be a flexible flexible substrate.

  As shown in FIG. 1, the negative electrode active material layer 12 has a substantially semicircular cross-sectional shape. As shown in FIG. 2, the negative electrode active material layer 12 extending along the Y direction on the negative electrode current collector 10. A stripe active (line and space structure) negative electrode active material layer pattern 12A is formed in which a large number of are arranged at regular intervals in the X direction. The negative electrode active material layer 12 has a high aspect ratio and a high height.

As the negative electrode active material contained in the negative electrode active material layer 12, those commonly used in the technical field of the present invention can be used. For example, metals, metal fibers, carbon materials, oxides, nitrides, silicon, silicon compounds, tin , Tin compounds, various alloy materials, and the like. Of these, oxides, carbon materials, silicon, silicon compounds, tin, tin compounds and the like are preferable in view of the capacity density. As the oxide, for example, the _{formula: Li 4/3 Ti 5/3-} x Fe x O 4 lithium titanate represented by (0 ≦ x ≦ 0.2) and the like. Examples of the carbon material include various natural graphite (graphite), coke, graphitizing carbon, carbon fiber, spherical carbon, various artificial graphite, amorphous carbon, and the like. Examples of the silicon compound include a silicon-containing alloy, a silicon-containing inorganic compound, a silicon-containing organic compound, a solid solution, and the like. Specific examples of the silicon compound include, for example, silicon oxide represented by SiO _a (0.05 <a <1.95), silicon and Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, An alloy containing at least one element selected from In, Sn, and Ti, silicon, silicon oxide, or a part of silicon contained in the alloy is B, Mg, Ni, Ti, Mo, Co, Ca, Cr, Cu, Examples thereof include silicon compounds or silicon-containing alloys substituted with at least one element selected from Fe, Mn, Nb, Ta, V, W, Zn, C, N, and Sn, and solid solutions thereof. Examples of the tin compound include SnO _b (0 <b <2), SnO ₂ , SnSiO ₃ , Ni ₂ Sn ₄ , Mg ₂ Sn, and the like. A negative electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type as needed.

  Moreover, the negative electrode active material layer 12 may contain the conductive support agent. As the conductive auxiliary agent, those commonly used in the technical field of the present invention can be used. For example, natural graphite, graphite such as artificial graphite, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black Carbon blacks such as carbon fibers, conductive fibers such as carbon fibers and metal fibers, metal powders such as carbon fluoride and aluminum, conductive whiskers such as zinc oxide, conductive metal oxides such as titanium oxide, and phenylene derivatives Organic conductive materials such as A conductive agent can be used individually by 1 type, or can be used in combination of 2 or more type as needed.

  On the upper side of the negative electrode active material layer 12, as shown in FIG. 1, a thin-film solid electrolyte layer 13 having a substantially constant thickness formed by a solid electrolyte is provided. The solid electrolyte layer 13 uniformly covers substantially the entire upper surface of the negative electrode 20 so as to follow the unevenness of the surface of the negative electrode 20 formed by the negative electrode current collector 10 and the negative electrode active material layer 12, and The surface of the solid electrolyte layer 13 also has an uneven shape.

Examples of the solid electrolyte contained in the solid electrolyte layer 13 include polymer electrolyte materials such as resins such as polyethylene oxide and / or polystyrene, and examples of the supporting salt include lithium hexafluorophosphate (LiPF ₆ ). , Lithium perchlorate (LiClO ₄ ), lithium bistrifluoromethanesulfonylimide (LiTFSI), and the like. A borate polymer electrolyte may be used. Of course, various additives may be mixed as long as the effects of the present invention are not impaired.

  As shown in FIG. 1, a positive electrode active material layer 16 is provided on the upper side of the solid electrolyte layer 14. The lower surface side of the positive electrode active material layer 16 has a concavo-convex shape along the concavo-convex shape of the upper surface of the solid electrolyte layer 14, but the upper surface side has a substantially flat shape. The positive electrode active material layer 16 also has a high aspect ratio and height in the same manner because the negative electrode active material layer 12 has a high aspect ratio and height as described above.

Examples of the positive electrode active material (powder) included in the positive electrode active material layer 16 include lithium-containing composite metal oxides, chalcogen compounds, and manganese dioxide. The lithium-containing composite metal oxide is a metal oxide containing lithium and a transition metal or a metal oxide in which a part of the transition metal in the metal oxide is substituted with a different element. Here, examples of the different elements include Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb, and B, and Mn, Al, Co, Ni, Mg and the like are preferable. One kind or two or more kinds of different elements may be used. Among these, lithium-containing composite metal oxides can be preferably used. The lithium-containing composite metal oxide, for _{example, Li x CoO 2, Li x} NiO 2, Li x MnO 2, Li x Co y Ni 1-y O 2, Li x Co y M 1-y O z, Li x _{Ni 1-y M y O z} , Li x Mn 2 O 4, Li x Mn 2-y M y O 4, LiMPO 4, Li 2 MPO 4 F ( in the respective formulas, for example, M is Na, Mg, Sc , Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb, V and B. At least one selected from the group consisting of 0 <x ≦ 1.2 and 0 <y ≦ 0. 9, 2.0 ≦ z ≦ 2.3), LiMeO ₂ (wherein Me = MxMyMz; Me and M are transition metals, x + y + z = 1), and the like. Specific examples of the lithium-containing composite metal oxide include LiNi _1/3 Mn _1/3 Co _1/3 O ₂ and LiNi _0.8 Co _0.15 Al _0.05 O ₂ . Here, x value which shows the molar ratio of lithium in each said formula increases / decreases by charging / discharging. Examples of the chalcogen compound include titanium disulfide and molybdenum disulfide. A positive electrode active material can be used individually by 1 type, and may use 2 or more types together. The positive electrode active material layer 16 may include the conductive additive described above with respect to the negative electrode active material layer 12.

  Thus, the positive electrode current collector 18 is laminated on the upper surface side of the positive electrode active material layer 16 having a substantially flat shape, and thereby the lithium ion secondary battery 1 is formed. As the positive electrode current collector 18, a material known in the technical field to which the present invention belongs can be used, and any metal film such as a copper foil or an aluminum foil may be used. Although not shown, the positive electrode current collector 18 may be formed on the surface of an insulating base material. As such a base material, a flat plate member made of an insulating material may be used. Examples of such an insulating material include resin, glass, ceramics, and the like. The base material may be a flexible flexible substrate.

  Although not shown, this lithium ion battery secondary battery 1 may be provided with a tab electrode as appropriate, and a plurality of lithium ion battery secondary batteries 1 are connected in series and / or in parallel. It is good also as an ion secondary battery apparatus.

  The lithium ion secondary battery of this embodiment having such a structure is thin and easy to bend. Further, since the negative electrode active material layer 12 and the positive electrode active material layer 16 have a three-dimensional structure having irregularities as shown in the figure, the surface area with respect to the volume is increased, so the positive electrode active material layer 16 via the thin solid electrolyte layer 14. A large contact area can be secured, and high efficiency and high output can be obtained. Thus, the lithium ion secondary battery 1 of this embodiment is small and has high performance.

(2) Manufacturing Method and Manufacturing Device for Electrode and Lithium Ion Secondary Battery of the Present Embodiment Next, a method for manufacturing the electrode and the lithium ion secondary battery 1 according to the present embodiment will be described. When manufacturing the lithium ion secondary battery 1 of this embodiment, the negative electrode active material layer 12 is formed on the negative electrode current collector 10 shown in FIG. 1 to manufacture the negative electrode, and the negative electrode active material layer 12 of the negative electrode is manufactured. Then, the solid electrolyte 14 is formed on the upper surface, and then the positive electrode active material layer 16 and the positive electrode current collector 18 (positive electrode) are formed on the upper surface of the solid electrolyte 14.

(2-1) Negative Electrode First, a method for producing a negative electrode in the present embodiment will be described. The negative electrode of this embodiment is manufactured by the method for manufacturing a battery electrode of the present invention having the following steps (a) to (c).
(A) A nozzle for discharging a paste-like negative electrode active material in a linear shape is moved relative to the long negative electrode current collector, and a linear negative electrode active material layer is formed on the negative electrode current collector. A coating process for forming a negative electrode active material pattern;
(A) a first drying step in which the negative electrode active material pattern is dried at a first drying temperature; and (c) a second negative electrode active material pattern that is higher than the first drying temperature after the first drying step. The 2nd drying process dried at the drying temperature of.

  Here, in FIG. 3, the manufacturing apparatus for enforcing the manufacturing method of the negative electrode of this embodiment is shown notionally. As shown in FIG. 3, the negative electrode manufacturing apparatus 100 according to the present embodiment includes a front part for performing the coating step (a) and the first drying step (a), and the second drying step (c). And a rear stage portion for implementation.

Negative preliminary portion of the manufacturing apparatus 100 of the present embodiment, first, the anode current collector 10 from the payout roller 30 is conveyed in the direction of arrow Y ₁ by the conveying roller 32 and the conveying roller 34, the take-up roller 36 It has the structure wound up. That is, it can be said that the transport roller 32 and the transport roller 34 are scanning means for moving the nozzle 40 relative to the negative electrode current collector 10. As described above, the active material layer made of the negative electrode active material layer 12 is formed on the surface of the negative electrode current collector 10 as shown in FIG. 2 until it comes out of the take-out roller 30 and is taken up by the take-up roller 36. A pattern 12A is formed.

(A) Application Step A paste-like negative electrode active material is linearly discharged from the nozzle 40 onto the surface of the negative electrode current collector 10 being conveyed. In the present embodiment, the nozzle 40 is fixed, and the negative electrode current collector 10 is conveyed, whereby the nozzle 40 is moved relative to the negative electrode current collector 10.

The paste-like negative electrode active material is composed of a mixture obtained by stirring and mixing (kneading) the negative electrode active material, the conductive auxiliary agent, a binder, a solvent, and the like by a conventional method, and a nozzle. In this embodiment, for example, it is preferable that the shear rate is 1 s ⁻¹ and the lower limit is about 10 Pa · s and the upper limit is about 10000 Pa · s. Each component may be dissolved or dispersed in a solvent (including the case where a part is dissolved and the remainder is dispersed).

  Further, the solid content ratio of the negative electrode active material used in the coating process can have various solid content ratios so that the negative electrode active material can be discharged from the nozzle 40, but from the solid content ratio at the wet point of the mixture. Preferably have a small solid content ratio.

  These viscosities and solid content ratios vary depending on the types and blending amounts, dimensions, shapes, etc. of components such as the negative electrode active material, conductive auxiliary agent, binder and solvent, but the negative electrode active material and the conductive auxiliary agent. And the length of the kneading time when the binder, the solvent and the like are agitated and mixed (kneaded) by a conventional method.

  As the binder, those commonly used in the technical field of the present invention can be used. For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethylene, polypropylene, aramid resin, polyamide, polyimide, polyamideimide , Polyacrylonitrile, polyacrylic acid, polyacrylic acid methyl ester, polyacrylic acid ethyl ester, polyacrylic acid hexyl ester, polymethacrylic acid, polymethacrylic acid methyl ester, polymethacrylic acid ethyl ester, polymethacrylic acid hexyl ester, poly Vinyl acetate, polyvinyl pyrrolidone, polyether, polyether sulfone, polyhexafluoropropylene, styrene-butadiene rubber, ethylene-propylene diene copolymer, carboxymethyl cellulose And the like. Copolymers of monomer compounds selected from tetrafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, pentafluoropropylene, fluoromethyl vinyl ether, acrylic acid, hexadiene, etc. May be used as a binder. A binder can be used individually by 1 type, or can be used in combination of 2 or more type as needed.

As the solvent, it is preferable to use an organic solvent excluding water so as not to decompose lithium hexafluorophosphate (LiPF ₆ ) and the like constituting the solid electrolyte layer 14. As the organic solvent, those commonly used in the technical field of the present invention can be used, and examples thereof include dimethylformamide, dimethylacetamide, methylformamide, N-methyl-2-pyrrolidone (NMP), dimethylamine, acetone, and cyclohexanone. Can be mentioned. An organic solvent can be used individually by 1 type, or can mix and use 2 or more types.

  Here, FIG. 4A schematically shows a state in which the negative electrode active material layer pattern 12A composed of the negative electrode active material layer 12 is formed in the negative electrode active material manufacturing apparatus 100 of the present embodiment shown in FIG. FIG. 4B is a side view (ie, a view seen from a direction substantially parallel to the main surface of the conveyed negative electrode current collector 10), and FIG. 4B is a negative electrode active material layer 12 composed of a negative electrode active material layer 12. It is a perspective view showing typically signs that material layer pattern 12A is formed.

In this nozzle dispensing method, a nozzle 40 having one or a plurality of discharge ports (not shown) for discharging a negative electrode active material that is a coating solution is disposed above the negative electrode current collector 10. While discharging a certain amount of negative electrode active material from the discharge port, the negative electrode current collector 10 is conveyed at a constant speed in the direction of the arrow Y ₁ relative to the nozzle 40. By doing so, a plurality of negative electrode active material layers 12 are formed on the negative electrode current collector 10 along the Y direction and applied in stripes. In the present embodiment, as shown in FIGS. 1 and 2, since the cross-sectional shape of the negative electrode active material layer 12 is substantially semicircular, the discharge port of the nozzle 40 also has a substantially semicircular shape.

  If a plurality of discharge ports are provided in the nozzle 40, a plurality of negative electrode active material layers 12 can be formed into a stripe shape. By continuing the conveyance of the negative electrode current collector 10, the negative electrode current collection from the unwinding roller 30 The negative electrode active material layer 12 can be formed in a stripe shape on the entire surface of the electric body 10.

(A) First drying step Since the striped negative electrode active material layer pattern 12A composed of the plurality of negative electrode active material layers 12 formed as described above is still in the state of a coating film containing a solvent or the like, The negative electrode current collector 10 provided with the material layer pattern 12A is conveyed so as to pass through the lower region of the blower 42 which is a drying means. In this lower region, the first drying step is performed by the dry air 44 on the negative electrode active material layer pattern 12 </ b> A composed of the plurality of negative electrode active material layers 12.

  The drying temperature in the first drying step may be in a range that does not impair the effects of the present invention, but may be, for example, in the range of 5 ° C to 50 ° C, preferably in the range of normal temperature (23 ° C) to 50 ° C. That's fine. Moreover, although the drying time of a 1st drying process can also be controlled by the conveyance speed of the negative electrode electrical power collector 10, and changes also with a composition and solid content ratio of a negative electrode active material layer, it may be about 1 to 60 minutes.

  Here, in this first drying step, the solid content ratio of the negative electrode active material after application (that is, the negative electrode active material pattern 12A made of the negative electrode active material layer 12) is the wet point of the negative electrode active material before application. It is preferable to vaporize the solvent in the negative electrode active material pattern 12A composed of the negative electrode active material layer 12 and discharge it to the outside until it is substantially equal to the solid content ratio. If the solid content ratio of the negative electrode active material when discharged from the nozzle 40 is 60% by mass, the solid content ratio of the negative electrode active material after coating is, for example, 70% by mass or more by the first drying step. And

(C) Second Drying Step Next, the structure (negative electrode) 20 including the negative electrode current collector 10 having the negative electrode active material layer 12 that has undergone the first drying step is wound on a winding roller 36 as shown in FIG. The rolled negative electrode 50 obtained by winding is subjected to the second drying step.

  In this second drying step, the roll-shaped negative electrode 50 is carried into the heating / drying furnace 52 and placed on the support 54 provided in the heating / drying furnace 52, where the first negative temperature exceeds the first drying temperature. Dry at a drying temperature of 2. As the heating and drying furnace 52, for example, a drying furnace using hot air, far infrared rays, or vacuum drying can be used.

  The drying temperature in the second drying step is higher than the drying temperature in the first drying step, and the upper limit may be in a range that does not impair the effects of the present invention. For example, in the range of 70 ° C to 150 ° C, for example, 80 ° C. I just need it. The drying time in the second drying step may be approximately 10 minutes to 24 hours.

  In this second drying step, the negative electrode active material layer 12 is applied until the solid content ratio of the negative electrode active material after coating (that is, the negative electrode active material pattern 12A made of the negative electrode active material layer 12) is substantially 100% by mass. The solvent in the negative electrode active material pattern 12A is vaporized and discharged to the outside. Note that the second drying step may be performed in multiple steps.

  In the negative electrode manufacturing apparatus 100 shown in FIG. 3, although not shown, the negative electrode active material layer 12 is thus dried at the first drying temperature and then dried at the second drying temperature higher than the first drying temperature. Further, control means for controlling the transport roller 32, the transport roller 34, the blower 42 and the heating / drying furnace 52 is provided. By performing such a two-step drying process, a thick negative electrode active material layer 12 can be formed with a high aspect ratio without impairing the shape and dimensions, and a lithium ion secondary battery having excellent charge / discharge capacity, etc. A negative electrode for realizing the battery is obtained.

  At this time, the negative electrode active material layer 12 is raised with respect to the surface of the substantially flat negative electrode current collector 10, and the negative electrode active material material is simply placed so that the upper surface of the negative electrode active material layer 12 is flat. Compared with the case of application, the surface area relative to the amount of the negative electrode active material used can be increased, and the area facing the positive electrode active material layer to be formed later can be increased to realize a large capacity.

(2-2) Solid Electrolyte Layer As a method for forming the solid electrolyte layer 14 on the upper surface of the negative electrode 20 composed of the negative electrode current collector 10 and the negative electrode active material layer 12 as described above, a conventionally known method is adopted. Although not particularly limited, in the present embodiment, the solid electrolyte layer 14 is formed by applying a solid electrolyte material, for example, by spin coating.

  FIG. 5 is a diagram schematically showing the state of application of the solid electrolyte material by spin coating in the present embodiment. As shown in FIG. 5, a negative electrode 20 formed by laminating a negative electrode current collector 10 and a negative electrode active material layer 12 is a rotary stage that is rotatable around a rotation axis in the vertical direction (Z direction) in a predetermined rotation direction Dr. 60 is mounted substantially horizontally.

  Therefore, in the present embodiment, the negative electrode composed of the negative electrode current collector 10 on which the negative electrode active material layer 12 is formed can be placed on the rotary stage 60 in a direction substantially perpendicular to the length direction of the negative electrode current collector 10. After cutting into dimensions, the solid electrolyte layer 14 is formed.

  The rotary stage 60 rotates at a predetermined rotational speed, and a paste-like solid electrolyte material 64 as a coating solution is discharged toward the negative electrode 20 from a nozzle 62 provided at an upper position on the rotary shaft of the rotary stage 60. . The solid electrolyte material dropped on the upper surface of the negative electrode 20 gradually spreads around by the centrifugal force of the rotating rotary stage 60, and excess solid electrolyte material is blown off from the end of the negative electrode 20.

  With such a mechanism, the upper surface of the negative electrode 20 is thinly and uniformly covered with the solid electrolyte material, and the solid electrolyte layer 14 can be formed by drying and curing this. What is necessary is just to select suitably according to a conventionally well-known method about the composition of a solid electrolyte material to be used, a viscosity and solid content ratio, and the conditions of dry hardening in the range which does not impair the effect of this invention.

  In the spin coating method, the thickness of the solid electrolyte layer 14 to be obtained can be controlled by the viscosity of the solid electrolyte material and the rotation speed of the rotary stage 60, and the surface is uneven as in the negative electrode 20 in the present embodiment. A thin-film solid electrolyte layer 14 having a uniform film thickness can be formed along the unevenness even on an object to be coated.

  The thickness of the solid electrolyte layer 14 is arbitrary, but it is necessary that the negative electrode active material layer 12 and the positive electrode active material layer 16 be reliably separated from each other and that the internal resistance be not too high. is there. In order not to impair the effect of the increased surface area by providing irregularities on the negative electrode active material layer 12, the thickness t14 of the solid electrolyte layer 14 (symbol t14 in FIG. 1) and the irregularities of the negative electrode active material layer 12 It is desirable that the height difference t12 (symbol t12 in FIG. 1) satisfies the relational expression: t14 <t12.

(2-3) Positive Electrode A method of forming the positive electrode active material layer 16 on the upper surface of the laminate 70 formed by laminating the negative electrode current collector 10, the negative electrode active material layer 12, and the solid electrolyte layer 14 formed as described above. In the present embodiment, a positive electrode active material layer 16 is applied by applying a paste-like positive electrode active material by, for example, a doctor blade method. Form.

  As the positive electrode active material, a material obtained by stirring and mixing (kneading) the above-described positive electrode active material, conductive additive, binder, solvent and the like can be used. What is necessary is just to select suitably according to a conventionally well-known method about the viscosity and solid content ratio, and the conditions of dry hardening in the range which does not impair the effect of this invention.

  FIG. 6 is a diagram schematically showing a state of application of the positive electrode active material by the doctor blade method. More specifically, FIG. 6A is a side view schematically showing that the positive electrode active material layer 16 is formed by applying the positive electrode active material on the upper surface of the laminate 70 by the doctor blade method (that is, FIG. 6B is a view seen when viewed from a direction substantially parallel to the main surface of the negative electrode current collector 10 having the negative electrode active material layer 12. FIG. It is a perspective view which shows a mode that the material layer 16 is formed typically.

Nozzles 72 for ejecting positive electrode active material is scanned moved in the direction indicated by the relatively arrow Y ₂ with respect to stack 70. In the moving direction Y ₂ of the nozzle 72, a doctor blade 74 is attached to the rear side of the nozzle 70, and the lower end of the doctor blade 74 is located above the solid electrolyte layer 14 formed on the upper surface of the laminate 70. Since the upper surface of the discharged positive electrode active material is in contact, the positive electrode active material layer 16 having a flat upper surface can be obtained.

The nozzles 72 used in this step may be a nozzle having a plurality of ejection ports as the nozzle 40 shown in FIG. 4, extending in a direction perpendicular to the moving direction Y ₂ (i.e., the direction of the arrow X) A nozzle having a slit-like discharge port may be used.

  In this way, by applying the positive electrode active material to the laminate 70, the positive electrode active material layer 16 having an unevenness along the unevenness of the solid electrolyte layer 14 on the lower surface and a substantially flat upper surface is formed on the laminate 70. Can be formed on the upper surface of the substrate.

  By laminating the positive electrode current collector 18 on the upper surface of the positive electrode active material layer 16 formed as described above, the lithium ion secondary battery 1 of the present embodiment having the structure shown in FIG. 1 can be obtained. . As the positive electrode current collector 18, a conventionally known material can be used, and for example, a metal foil such as a copper foil can be used.

  At this time, it is preferable to stack the positive electrode current collector 18 before the positive electrode active material layer 16 is cured, because the positive electrode active material layer 16 and the positive electrode current collector 18 can be brought into close contact with each other and bonded. Moreover, since the upper surface of the positive electrode active material layer 16 is substantially flat, the positive electrode current collector 18 can be stacked without any gap.

<< Embodiment 2 >>
In the present embodiment, the structure (negative electrode) obtained after forming the negative electrode active material layer on the negative electrode current collector is subjected to the first drying step, then cut and then subjected to the second drying step, The same as in the first embodiment. Here, it demonstrates centering on difference with Embodiment 1. FIG.

  In FIG. 7, the manufacturing apparatus for enforcing the manufacturing method of the negative electrode of this embodiment is shown notionally. As shown in FIG. 7, the negative electrode manufacturing apparatus 200 according to the present embodiment performs the former part for performing the coating process (A) and the first drying process (A), and the second drying process (C). And a subsequent stage portion.

Preliminary portion of the negative electrode manufacturing apparatus 200 of the present embodiment, first, the negative electrode current collector 10 from the payout roller 30 and the conveyance roller 32 is conveyed in the direction of arrow Y _1, to reach the conveying rollers 34a and 34b In the meantime, as shown in FIG. 2, an active material layer pattern 12 </ b> A composed of the negative electrode active material layer 12 is formed on the surface of the negative electrode current collector 10, and the negative electrode current collector 10 having the negative electrode active material layer 12 is formed. A structure (negative electrode) 20 is obtained.

  The structure (negative electrode) 20 composed of the negative electrode current collector 10 having the negative electrode active material layer 12 is then positioned by being sandwiched from above and below by the transport rollers 34a and 34b, and then cut into a sheet by the cutting mechanism 36. The obtained sheet-like negative electrode 20A is subjected to the second drying step while being sandwiched from above and below by the transport rollers 36a and 36b and the transport rollers 38a and 38b.

(A) Application process In the application process, as in the first embodiment, a paste-like negative electrode active material is linearly discharged from the nozzle 40 onto the surface of the negative electrode current collector 10 to be conveyed, and a plurality of negative electrodes A stripe-shaped negative electrode active material layer pattern 12A made of the active material layer 12 is formed.

(A) First drying step Since the plurality of negative electrode active material layers 12 formed as described above are in the state of a coating film that still contains a solvent or the like, from the negative electrode current collector 10 having the negative electrode active material layer 12. The resulting structure (negative electrode) 20 is then conveyed so as to pass through the lower region of the blower 42, and the first drying step is performed by the dry air 44 in the lower region.

(C) Second Drying Step After the first drying step, the structure (negative electrode) 20 composed of the negative electrode current collector 10 having the negative electrode active material layer 12 is transferred to the transport rollers 34a and 34b as shown in FIG. And sandwiched from above and below (both ends of the negative electrode current collector 10 where the negative electrode active material layer 12 is not provided) and cut by the cutting mechanism 46 from above and below to form a sheet-like structure (negative electrode) 20. The paper is conveyed to the heating and drying furnace 52A while being sandwiched from above and below by the conveyance rollers 36a and 36b and the conveyance rollers 38a and 38b.

  The heating and drying furnace 52A has a cabinet structure having a plurality of shelves 52B, and the second heating step can be performed by placing the sheet-like structure (negative electrode) 20 on the shelves 52B. As the heating and drying furnace 52A, for example, a vacuum drying furnace or the like can be used.

  By performing such a two-step drying process, the negative electrode active material layer 12 having a high aspect ratio can be formed without impairing the shape and dimensions of the negative electrode active material pattern 12A, and the charge / discharge capacity is excellent. A negative electrode for realizing a battery such as a lithium ion secondary battery is obtained. Further, the solid electrolyte layer 14, the positive electrode active material layer 16, and the positive electrode current collector 18 are added to the sheet-like structure (negative electrode) 20 obtained as described above in the same manner as described in the first embodiment. By providing, a battery such as a lithium ion secondary battery having excellent charge / discharge capacity can be obtained.

≪Deformation mode≫
As mentioned above, although the example of embodiment of this invention was demonstrated, this invention is not limited only to these.
For example, in the above embodiment, the case where the negative electrode active material layer 12 is formed first, and the coating process, the first drying process, and the second drying process are used only in the formation has been described. May be formed first, and the coating process, the first drying process, and the second drying process may be used for the formation.

  When the positive electrode active material layer is formed by the coating process, the first drying process and the second drying process according to the electrode manufacturing method of the present invention, the same conditions as in the case of the negative electrode active material layer may be adopted. If the solid content ratio of the paste-like positive electrode active material used in the process is about 50% by mass, the solid content ratio of the positive electrode active material layer after coating is set to, for example, 60% by mass or more by the first drying step. That's fine.

  Moreover, in the said embodiment, although the application | coating process, the 1st drying process, and the 2nd drying process were demonstrated only in formation of the negative electrode active material layer 12, the negative electrode active material layer 12 and the positive electrode active material layer 16 were demonstrated. Any of these may be formed using a coating process, a first drying process, and a second drying process.

  Moreover, in the said embodiment, after forming the negative electrode active material layer 12 by the application | coating process, after performing a 1st drying process and a 2nd drying process continuously, the solid electrolyte layer 14, the positive electrode active material layer 16, and a positive electrode Although the case where the current collector 18 is provided has been described, after the first drying step, the solid electrolyte layer 14, the positive electrode active material layer 16, and the positive electrode current collector 18 are provided, and then the second drying step is performed. I do not care.

  Moreover, in the said embodiment, in the negative electrode manufacturing method of this invention, although demonstrated about the case where the 1st drying process after an application | coating process was implemented with an air blower, you may dry naturally without using an air blower, Vacuum drying may be performed.

  In the above embodiment, the drawing pattern of the negative electrode active material layer 12 on the negative electrode current collector 10 has a so-called line-and-space structure composed of a plurality of stripes arranged at regular intervals. It is not limited. In the above-described embodiment, the case where the cross-sectional shape of the negative electrode active material layer 12 is substantially semicircular has been described. May be.

  Since the application by the nozzle dispensing method is applied to the formation of the negative electrode active material layer 12 that needs to form a concavo-convex pattern, various patterns can be formed in a short time. Also, the nozzle dispensing method can be suitably applied to the creation of a fine pattern. In this manufacturing method, it is only necessary to create a fine pattern only in the first coating step, that is, the coating step of the active material coating solution. If the uniform coating can be performed in the subsequent coating step, the fine pattern is sufficient. No production is required.

  The present invention is not limited to the above embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, the coating method applied in each step is not limited to the above, and other coating methods may be applied as long as they meet the purpose of the step. For example, in the above-described embodiment, the spin coating method is applied to form the solid electrolyte layer 14, but any other method can be used as long as it can form a thin film that follows the unevenness of the surface to be coated. For example, the solid electrolyte material may be applied by a spray coating method.

  Further, for example, in the above embodiment, the doctor blade method is applied to form the positive electrode active material layer 16. Any other application method may be used as long as it is possible. In order to achieve such an object, it is desirable that the viscosity of the positive electrode active material is not so high. It is possible to finish the unevenness and to make the upper surface substantially flat. For example, it may be applied by a nozzle dispensing method, a slit coating method, a bar coating method, or the like.

  Further, in the above embodiment, the case where the all solid state lithium ion secondary battery having the structure shown in FIG. 1 is manufactured has been described. However, the present invention is not limited to this, and the present invention is not limited to the lithium ion having the structure shown in FIG. The present invention can also be applied when manufacturing a secondary battery.

  FIG. 8 is a schematic longitudinal sectional view of a lithium ion secondary battery manufactured in a modification of the present invention. In the lithium ion secondary battery 201 shown in FIG. 8, the negative electrode active material layer 112 is provided on one surface (the upper surface in FIG. 8) of the negative electrode current collector 110 by the electrode manufacturing method of the present invention, A negative electrode is configured. Further, the positive electrode active material layer 116 is provided on one surface (the lower surface in FIG. 8) of the positive electrode current collector 118 by the electrode manufacturing method of the present invention, thereby forming a positive electrode.

  Then, the negative electrode (the negative electrode active material layer 112 and the negative electrode current collector 110) and the positive electrode (the positive electrode active material layer 116 and the positive electrode current collector 118) are placed facing each other with a spacer 202 made of, for example, an insulating material. After being put in the battery can, an electrolyte solution is injected into the internal space formed by the negative electrode current collector 110, the spacer 202, and the positive electrode current collector 118, and the battery can is sealed. 201 is configured.

Example 1
First, lithium cobaltate (LiCoO ₂ , a positive electrode active material manufactured by Nippon Chemical Industry Co., Ltd.), acetylene black (conducting aid manufactured by Denki Kagaku Kogyo Co., Ltd.), and polyvinylidene chloride (manufactured by Kishida Chemical Co., Ltd.) And a mixture of the obtained mixture and N-methyl-2-pyrrolidone to obtain a positive electrode active material having a solid content of 60% by mass. (Viscosity: 1000 Pa · s).

  While moving a nozzle having a slit with a width of 70 μm and a height of 150 μm relative to the surface of the aluminum foil, the positive electrode active material is applied onto the surface of the aluminum foil from the slit, and a linear positive electrode active material A coating film of the material was obtained (application process).

  Next, the coating film of the positive electrode active material obtained by the coating step was naturally dried at room temperature (25 ° C.) for 0, 10, 20, 30, 40, 50, or 60 minutes (first drying step).

  Then, the coating film of the positive electrode active material material which passed through the 1st drying process was heat-dried at 80 degreeC for 1 hour (2nd drying process), and, thereby, the positive electrode active material layer was obtained. The width and height of the positive electrode active material layer at this time were measured with a laser microscope manufactured by Keyence Corporation, the aspect ratio was calculated, and these are shown in FIG.

≪Comparative example 1≫
While moving a nozzle having a slit with a width of 70 μm and a height of 150 μm relative to the surface of the aluminum foil, the positive electrode active material is applied onto the surface of the aluminum foil from the slit, and a linear positive electrode active material A coating film of the material was obtained (application process).

Next, the coating film of the positive electrode active material obtained by the coating step is 0 at room temperature (25 ° C.).
It was naturally dried for 3, 5, 9, 13, 18, 21, 26, 32, 36, 42, 49, 54 or 60 minutes (drying step), thereby obtaining a positive electrode active material layer. The width and height of the positive electrode active material layer at this time were measured with a laser microscope manufactured by Keyence Corporation, the aspect ratio was calculated, and these are shown in FIG.

  9 and 10 that the positive electrode active material layer having a high aspect ratio can be obtained through the second drying step if the first drying time is 10 minutes or more. Moreover, in the said Example 1, the solid content ratio of the coating film of positive electrode active material material was calculated | required by measuring the time-dependent change of mass with an electronic balance every 0.5 minute of drying time. The results are shown in FIG. In the graph of FIG. 11, the horizontal axis indicates the drying time (minutes), and the vertical axis indicates the solid content ratio of the coating film of the positive electrode active material. It was confirmed that the solid content ratio at the wet point of this positive electrode negative electrode active material was about 70% by mass.

<< Example 2 >>
First, lithium titanate (Li ₄ Ti ₅ O ₁₂ , negative electrode active material manufactured by Ishihara Sangyo Co., Ltd.), acetylene black (conducting aid manufactured by Denki Kagaku Kogyo Co., Ltd.), and polyvinylidene chloride (Kishida Chemical ( Binder manufactured by the same company) is mixed at a mass ratio of 8: 1: 1, the resulting mixture and N-methyl-2-pyrrolidone are mixed, and the negative electrode active material having a solid content ratio of 50% by mass (Viscosity: 600 Pa · s).

  While moving a nozzle having a slit with a width of 70 μm and a height of 150 μm relative to the surface of the aluminum foil, the negative electrode active material is applied onto the surface of the aluminum foil from the slit, and a linear negative electrode active material A coating film of the material was obtained (application process).

  Next, the coating film of the negative electrode active material obtained by the coating step was naturally dried at room temperature (25 ° C.) for 0, 10, 20, 30, 40, 50, or 60 minutes (first drying step).

  Then, the coating film of the negative electrode active material material which passed through the 1st drying process was heat-dried at 80 degreeC for 1 hour (2nd drying process), and, thereby, the negative electrode active material layer was obtained. The width and height of the negative electrode active material layer at this time were measured with a laser microscope manufactured by Keyence Corporation, the aspect ratio was calculated, and these are shown in FIG.

«Comparative example 2»
While moving a nozzle having a slit with a width of 70 μm and a height of 150 μm relative to the surface of the aluminum foil, the negative electrode active material is applied onto the surface of the aluminum foil from the slit, and a linear negative electrode active material A coating film of the material was obtained (application process).

Next, the coating film of the negative electrode active material obtained by the coating step is 0 at room temperature (25 ° C.).
It was naturally dried for 3, 5, 9, 13, 18, 21, 26, 32, 36, 42, 49, 54 or 60 minutes (drying step), whereby a negative electrode active material layer was obtained. The width and height of the negative electrode active material layer at this time were measured with a laser microscope manufactured by Keyence Corporation, the aspect ratio was calculated, and these are shown in FIG.

  12 and 13 that the negative electrode active material layer having a high aspect ratio can be obtained through the second drying step if the first drying time is 45 minutes or longer. Further, in Example 2 described above, the solid content ratio of the coating film of the negative electrode active material was determined by measuring the change with time of the mass with an electronic balance every 0.5 minutes. The results are shown in FIG. In the graph of FIG. 14, the horizontal axis indicates the drying time (minutes), and the vertical axis indicates the solid content ratio of the coating film of the negative electrode active material. It was confirmed that the solid content ratio at the wet point of this negative electrode active material was about 60% by mass.

1,201 ... Lithium ion secondary battery,
10 ... negative electrode current collector,
12 ... negative electrode active material layer,
12A ... negative electrode active material layer pattern,
14 ... solid electrolyte layer,
16 ... positive electrode active material layer,
18 ... positive electrode current collector,
20 ... Structure (negative electrode),
20A ... sheet-like negative electrode,
30 ... Unwinding roller,
32 ... Conveying roller,
34, 34a, 34b ... conveying rollers,
36 ... take-up roller,
36a, 36b ... conveying rollers,
38a, 38b ... conveying rollers,
40 ... Nozzle,
42 ... Blower,
44 ... Dry air,
46 ... cutting mechanism,
50 ... Rolled negative electrode,
52 ... heating and drying furnace,
52A ... heating and drying furnace,
52B ... shelf
54 ... Support,
60 ... rotary stage,
62 ... Nozzle,
64 ... Solid electrolyte material,
70: Structure,
72 ... Nozzle,
74 ... Doctor blade,
110 ... negative electrode current collector,
112 ... negative electrode active material layer,
114 ... electrolyte solution,
116 ... positive electrode active material layer,
118... Positive electrode current collector,
202: Spacer.

Claims (2)

An application step of forming a linear active material pattern on the current collector by moving a nozzle for discharging the paste-like active material material in a linear shape relative to the current collector;
A first drying step of drying the active material pattern at a first drying temperature within a range of 5 ° C to 50 ° C ;
A second drying step of drying the active material pattern after the first drying step at a second drying temperature within a range of 70 ° C. to 150 ° C. higher than the first drying temperature;
Only including,
In the coating step, the active material is a mixture containing at least an active material powder and a solvent, and the mixture has a solid content ratio smaller than a solid content ratio at a wet point of the mixture,
In the first drying step, the solvent in the active material pattern is vaporized and discharged out of the active material pattern until the solid content ratio of the active material pattern becomes equal to the solid content ratio at the wet point of the mixture. ,
Forming an active material pattern having an aspect ratio of 0.4 or more on the current collector;
A method for producing an electrode for a battery characterized by the above. A nozzle that discharges a paste-like active material in a line;
Scanning means for moving the nozzle relative to the current collector to form a linear active material pattern on the current collector;
Drying means for drying the active material pattern formed on the current collector;
The active material pattern is dried at a first drying temperature within a range of 5 ° C. to 50 ° C., and then dried at a second drying temperature within a range of 70 ° C. to 150 ° C. higher than the first drying temperature. Control means for controlling the drying means;
Including
The active material is a mixture containing at least an active material powder and a solvent, and the mixture has a solid content ratio smaller than a solid content ratio at a wet point of the mixture,
The control means dries the active material pattern at a first drying temperature until the solid content ratio of the active material pattern becomes equal to the solid content ratio at the wet point of the mixture, and the solvent in the active material pattern Vaporizing and discharging out of the active material pattern,
The aspect ratio of the active material pattern on the current collector is 0.4 or more,
A battery electrode manufacturing apparatus .

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