JP2011034918A - Method for manufacturing electrode plate for laminated secondary battery, and electrode plate material for laminated secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrode plate for a laminated secondary battery in which yield and productivity are improved, and an electrode plate material for the laminated secondary battery. <P>SOLUTION: In the electrode plate material 1000 composed of a belt-like material in which a coating region 1100 of a coated mixture containing an active material and a non-coating region 1200 of the non-coated mixture are arranged alternately and continuously in a length direction, the coating region 1100 is cut at the center part of the length direction and the non-coating region 1200 is cut at the center part of the length direction. A length (2a) of the coating region 1100 is nearly twice a length (a) of a part of the coating region 1100 that constitutes a single electrode plate 1 to constitute the lamination layer type secondary battery. A length (2b) of the non-coating region 1200 is nearly twice a length (b) of a part of the non-coating region 1200 that constitutes a single electrode plate 1 to constitute the lamination layer type secondary battery. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention generally relates to a method of manufacturing a laminated secondary battery electrode plate and a laminated secondary battery electrode material, and specifically includes an active material on the surface of a metal substrate as a current collector. The present invention relates to a method for producing a laminated secondary battery electrode plate formed by applying a composite material, and a laminated secondary battery electrode plate material.

  In recent years, batteries, particularly secondary batteries, have been used as power sources for portable electronic devices such as mobile phones and portable personal computers. As an example of a secondary battery, a lithium ion secondary battery is known to have a relatively large energy density.

  For example, Japanese Patent Laying-Open No. 2005-116482 (Patent Document 1) describes a configuration of a thin battery as a lithium ion secondary battery. In this thin battery, a positive electrode terminal in which a power generation element having a positive electrode plate and a negative electrode plate alternately stacked between separators is accommodated in an exterior member and sealed and connected to the power generation element via a plurality of current collectors And the negative terminal are led out from the outer peripheral edge of the exterior member in a direction facing each other. In such a stacked secondary battery, a plurality of positive plates and negative plates are alternately stacked in the exterior member with separators interposed therebetween.

  A method for manufacturing such an electrode plate of a laminated secondary battery is described in, for example, Japanese Patent Application Laid-Open No. 2001-155717 (Patent Document 2). In this electrode plate manufacturing method, first, a positive electrode active material is applied to both surfaces of an aluminum metal base material and dried to manufacture a positive electrode plate material. Moreover, a negative electrode active material is apply | coated on both surfaces of a copper metal base material, and a negative electrode plate material is manufactured by making it dry. Furthermore, a separator material is manufactured by apply | coating an insulating layer on the single side | surface of a PET film base material, and making it dry. Next, each of the positive electrode plate material, the negative electrode plate material, and the separator material is punched into a predetermined battery cell shape, whereby the positive electrode plate, the negative electrode plate, and the separator are manufactured. The obtained positive electrode plate, separator, and negative electrode plate are sequentially stacked and heated and pressurized to mechanically join to manufacture a battery element of a stacked secondary battery.

JP-A-2005-116482 JP 2001-155717 A

  FIG. 7 is a partial plan view showing an electrode plate material of a conventional stacked secondary battery. The strip-shaped electrode plate material 500 shown in FIG. 7 is a positive electrode plate material or a negative electrode plate material used for a stacked type secondary battery of a type in which a positive electrode terminal and a negative electrode terminal are led out from the outer peripheral edge of the exterior member to each other. It is.

  As shown in FIG. 7, in the electrode plate material 500, a coating region 510 in which a composite material containing an active material is coated and a non-coating region 520 in which the composite material is not coated are alternately long. It is arranged continuously in the direction. As described in JP-A-2001-155717 (Patent Document 2), this electrode plate material 500 is punched into a predetermined battery cell shape to form an electrode plate 51, and the positive and negative electrode plates 51 are further separated into separators. The battery elements of the stacked type secondary battery are formed by alternately stacking the layers.

  However, if the composite material adheres to an end portion of a part of the non-coating region 520 (non-coating region 520 shown on the left side of FIG. 7) constituting each electrode plate 51, a problem of poor bonding with the external terminal occurs. There is. Further, if there is a non-coated portion in a part of the coating region 510 constituting each electrode plate 51, there is a problem that the battery characteristics are poor.

  In order to solve these problems, as shown in FIG. 7, when the electrode plate material 500 is formed, each of the coating regions 510 and the non-coating regions 520 that are alternately arranged in the electrode plate material 500 is formed. It is formed longer than the length required for a predetermined battery cell shape. Then, as shown in FIG. 7, first, the electrode plate material 500 is sequentially cut along cutting lines C10 and C30. Next, in order to cut off an excessive part, it cut | disconnects with the cutting line C20. In this way, each electrode plate 51 is formed. Alternatively, each electrode plate 51 shown in FIG. 7 is punched from the electrode plate material 500.

  In this method, the metal foil as the current collector for the discarding portion and the composite material containing the active material are wasted and the yield is lowered, so that there is a problem that the material cost is increased. Moreover, there is no problem when the electrode plate is formed by punching. However, when cutting with a cutting blade or the like, there is a problem that productivity is low because it is necessary to cut twice to obtain one electrode plate.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing a laminated secondary battery electrode plate and a laminated secondary battery electrode material capable of improving the yield and productivity for producing the electrode plate. That is.

  In the manufacturing method of the electrode plate for a stacked type secondary battery according to the present invention, the coating region where the composite material containing the active material is coated and the non-coating region where the composite material is not coated are alternately formed. In the manufacturing method of the electrode plate for laminated secondary batteries which manufactures an electrode plate by cut | disconnecting the strip | belt-shaped material continuously arrange | positioned in the length direction, it is provided with the following steps.

  (A) The step which cut | disconnects the center part of the length direction of a coating area | region.

  (B) The step which cut | disconnects the center part of the length direction of a non-coating area | region.

  In the manufacturing method of the electrode plate for a stacked type secondary battery according to the present invention, by cutting the central portion in the length direction of each of the coated region and the non-coated region, there is no disposal portion of the strip material. Each electrode plate composed of a half of the coating region and a half of the non-coating region can be manufactured by sequentially cutting the strip. For this reason, the yield for manufacturing an electrode plate can be improved. Further, by cutting the strip material once in sequence, a single electrode plate can be obtained, so that productivity can be improved.

  In the manufacturing method of the electrode plate for a laminated secondary battery according to the present invention, it is preferable that the length of the coating region of the strip-shaped material is approximately twice the length of the coating region after cutting.

  Moreover, in the manufacturing method of the electrode plate for laminated type secondary batteries of this invention, it is preferable that the length of the non-coating area | region of a strip | belt-shaped material is about twice the length of the non-coating area | region after a cutting | disconnection.

  The electrode plate material for a laminated type secondary battery according to the present invention has a length in which a coating region in which a composite material containing an active material is coated and a non-coating region in which the composite material is not coated are alternately formed. An electrode plate material for a laminated secondary battery made of a strip-like material continuously arranged in the direction has the following characteristics. The length of the coating region of the strip-shaped material is approximately twice the length of the coating region in the single electrode plate constituting the laminated secondary battery.

  In the electrode plate material for a laminated secondary battery according to the present invention, the length of the non-coated region of the strip is approximately twice the length of the non-coated region in the single electrode plate constituting the laminated secondary battery. It is preferable that

  According to the present invention, it is possible to improve the yield and productivity for manufacturing the electrode plate.

It is a schematic plan view which shows an example of the laminated secondary battery comprised using the electrode plate manufactured by the manufacturing method of the electrode plate for laminated secondary batteries of this invention. It is a fragmentary sectional view which expands and shows the cross section seen from the direction along the II-II line of FIG. It is a fragmentary sectional view which expands and shows the cross section seen from the direction along the III-III line of FIG. It is a fragmentary top view which shows the electrode plate material of a laminated type secondary battery as one embodiment of this invention. It is a fragmentary top view which shows the electrode plate material of a laminated type secondary battery as another embodiment of this invention. It is a fragmentary top view which shows the electrode plate material of a laminated type secondary battery as another embodiment of this invention. It is a fragmentary top view which shows the electrode plate material of the conventional laminated type secondary battery.

  An embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the stacked secondary battery 100 is connected to the battery element 10 through a battery element 10, an exterior member 20 that houses and seals the battery element 10, and a plurality of current collectors. It is comprised from the positive electrode terminal 30 and the negative electrode terminal 40 which were derived | led-out from the outer periphery of the exterior member 20 in the direction which mutually opposes.

  As shown in FIG. 2 and FIG. 3, the battery element 10 includes a plurality of positive plates 11, a plurality of negative plates 12, each between a plurality of positive plates 11 and a plurality of negative plates 12. It includes a plurality of separators 13 disposed so as to intervene and a non-aqueous electrolyte solution (not shown). Each of the plurality of positive electrode plates 11 and each of the plurality of negative electrode plates 12 are alternately stacked with each of the plurality of separators 13 interposed therebetween. The positive electrode plate 11, the negative electrode plate 12, and the separator 13 are formed in a plate shape, a film shape, a foil shape, or the like. For example, a laminated body in which a plurality of film-like positive electrode plates 11 and negative electrode plates 12 are laminated in close contact via separators 13 is filled in an exterior member 20 made of an aluminum laminate film. As shown in FIG. 3, the plurality of negative plates 12 are connected to the negative terminal 40 via a plurality of current collectors 41 (non-coating regions). Although not shown in figure, the some positive electrode plate 11 is similarly connected to the positive electrode terminal 30 (FIG. 1).

  The coating region of the positive electrode plate 11 is configured by forming a positive electrode mixture layer containing a positive electrode active material on both surfaces of a current collector. The coating region of the negative electrode plate 12 is configured by forming a negative electrode mixture layer containing a negative electrode active material on both surfaces of the current collector.

  For example, the coating region of the positive electrode plate 11 is formed by applying a positive electrode mixture containing a positive electrode active material, a binder, and a conductive additive on both surfaces of a current collector made of aluminum foil, and drying the positive electrode mixture. It is produced by forming a composite material layer on both sides of the current collector.

  In general, as the positive electrode active material, a metal oxide, a metal sulfide, or a specific polymer can be used depending on the type of the target battery.

When a lithium ion secondary battery is configured, a metal sulfide or oxide such as TiS ₂ , MoS ₂ , NbSe ₂ , or V ₂ O ₅ can be used as the positive electrode active material. In addition, LiM _x O ₂ (in the chemical formula, M represents one or more transition metals, x varies depending on the charge / discharge state of the battery, and is usually 0.05 or more and 1.10 or less as a positive electrode active material of a lithium ion secondary battery Lithium composite oxide mainly composed of As the transition metal M constituting this lithium composite oxide, Co, Ni, Mn and the like are preferable. Specific examples of such a lithium composite oxide include LiCoO ₂ , LiNiO ₂ , LiNi _y Co _1-y O ₂ (where 0 <y <1), and Li _{1 + a} (Ni _x Co _y Mn _z ) O. _2-b (in the chemical formula, −0.1 <a <0.2, x + y + z = 1, −0.1 <b <0.1), LiMn ₂ O _{4 and the} like. These lithium composite oxides can generate a high voltage and become a positive electrode active material having an excellent energy density. In order to produce the positive electrode plate 11, a plurality of these positive electrode active materials may be used in combination.

  Moreover, as a binder contained in said positive electrode mixture, the well-known binder normally used for the positive electrode mixture of a battery can be used, A conductive agent is used for said positive electrode mixture. For example, known additives can be added.

  For example, the negative electrode plate 12 is formed by uniformly applying a negative electrode mixture containing a negative electrode active material and a binder onto both surfaces of a current collector made of copper foil, and drying the negative electrode mixture layer. It is made by forming on both sides of the body.

When constituting a lithium ion secondary battery, it is preferable to use the material which can dope and dedope lithium as a negative electrode active material. As a material that can be doped or dedoped with lithium, for example, a carbon material such as a non-graphitizable carbon material or a graphite material can be used. Specifically, carbon materials such as pyrolytic carbons, cokes, graphites, glassy carbon fibers, organic polymer compound fired bodies, carbon fibers, and activated carbon can be used. Examples of the above cokes include pitch coke, needle coke, and petroleum coke. Moreover, said organic polymer compound fired body means what carbonized by baking a phenol resin, furan resin, etc. at a suitable temperature. In addition to the carbon material described above, as a material that can be doped or dedoped with lithium, a polymer such as polyacetylene or polypyrrole, or an oxide such as SnO ₂ or Li ₄ Ti ₅ O ₁₂ (lithium titanate) can also be used. .

  Moreover, as a binder contained in said negative electrode compound material, the well-known binder normally used for the negative electrode compound material of a lithium ion battery can be used, In said negative electrode compound material, Known additives and the like can be added.

The nonaqueous electrolytic solution is prepared by dissolving an electrolyte in a nonaqueous solvent. As the electrolyte, for example, a solution obtained by dissolving LiPF ₆ at a concentration of 1.0 mol / L in a non-aqueous solvent is used. As an electrolyte other than LiPF ₆ , lithium salts such as LiBF ₄ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiC (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , LiSiF ₆ are used. Can be mentioned. Among these, it is desirable from the viewpoint of oxidation stability that LiPF ₆ or LiBF ₄ is particularly used as the electrolyte. Such an electrolyte is preferably used by being dissolved in a non-aqueous solvent at a concentration of 0.1 mol / L to 3.0 mol / L, and dissolved at a concentration of 0.5 mol / L to 2.0 mol / L. More preferably, it is used. As the non-aqueous solvent, for example, a mixture of propylene carbonate, ethylene carbonate, and diethyl carbonate at a volume ratio of 5-20: 20-30: 60-70 is used. Other non-aqueous solvents include: cyclic carbonates such as propylene carbonate and ethylene carbonate; chain carbonates such as diethyl carbonate and dimethyl carbonate; carboxylic acid esters such as methyl propionate and methyl butyrate; γ-butyllactone, sulfolane, Ethers such as 2-methyltetrahydrofuran and dimethoxyethane can be used. These non-aqueous solvents may be used alone or in combination of two or more. Among these, it is preferable from the point of oxidation stability to use carbonate ester as a non-aqueous solvent.

  In the example of the laminated secondary battery described above, one separator is interposed between the positive electrode plate and the negative electrode plate, but a plurality of separators may be interposed. The material of the plurality of separators may be the same or different. Further, a long separator may be interposed between the positive electrode plate and the negative electrode plate in a ninety-nine fold.

  Next, a method for manufacturing the electrode plate of the stacked secondary battery configured as described above, that is, the positive electrode plate 11 or the negative electrode plate 12 will be described.

  As shown in FIG. 4, an electrode plate material 1000 as a material of a positive electrode plate or a negative electrode plate includes a coating region 1100 where a composite material containing an active material is applied, and a non-coating where no composite material is applied. The region 1200 is made of a strip-like material alternately arranged continuously in the length direction. The length (2a) of the coating region 1100 in the electrode plate material 1000 is a part of the coating region 1100 constituting the single electrode plate 1 constituting the laminated secondary battery, that is, the positive electrode plate 111 or the negative electrode plate 121. It is almost twice the length (a). Further, the length (2b) of the non-coated region 1200 in the electrode plate material 1000 is a single electrode plate 1 constituting the stacked secondary battery, that is, the non-coated region constituting the positive electrode plate 111 or the negative electrode plate 121. It is almost twice the length (b) of a part of 1200.

  A process of manufacturing each electrode plate 1 from the electrode plate material 1000 configured as described above will be described. First, the central portion in the length direction of the coating region 1100 is cut at the cutting line C1 (right cutting line C1) shown in FIG. Next, the central part of the length direction of the non-coating area | region 1200 is cut | disconnected in the cutting line C2. And the center part of the length direction of the coating area | region 1100 is cut | disconnected in the cutting line C1 (left side cutting line C1). Thus, each electrode plate 1 is formed by sequentially cutting the electrode plate material 1000.

  As described above, by cutting the central portions of the coating region 1100 and the non-coating region 1200 in the length direction, half of the coating region 1100 is formed so that there is no stripped portion of the strip material. Each electrode plate 1 composed of half of the non-coating region 1200 can be manufactured by sequentially cutting from a strip-shaped material. For this reason, the yield for manufacturing the electrode plate 1 can be improved. Moreover, since the electrode plate 1 of 1 sheet can be obtained by cut | disconnecting the electrode plate material 1000 which consists of strip | belt-shaped materials once in order, productivity can be improved.

  As shown in FIG. 5, in another embodiment of the present invention, the central portion in the length direction of the coating region 1100 is cut along the cutting line C3 (right cutting line C3). Next, a cut surface is formed in a T shape along the cutting line C4, and the central portion in the length direction of the non-coated region 1200 is cut. In this case, not only the length of the non-coating area | region 1200 which comprises each electrode plate 2, but the non-coating area | region part 1210 is cut off so that a width | variety may become substantially half. And the center part of the length direction of the coating area | region 1100 is cut | disconnected in the cutting line C3 (left side cutting line C3). In this way, each electrode plate 2 is formed by sequentially cutting the electrode plate material 1000. By doing in this way, a narrow non-coating area | region can be formed in the edge part of each electrode plate 2. FIG. In addition, as shown in FIG. 1, the electrode plate 2 has not only the stacked secondary battery 100 in which the positive electrode terminal 30 and the negative electrode terminal 40 are led out in opposite directions, but also the positive electrode terminal 30 and the negative electrode terminal 40 in the same direction. The present invention can also be applied to a stacked type secondary battery.

  As shown in FIG. 6, in another embodiment of the present invention, the central portion in the length direction of the coating region 1100 is cut along the cutting line C5 (the cutting line C5 on the right side). Next, a cut surface is formed so that a step is formed at the central portion in the width direction along the cutting line C6, and the central portion in the length direction of the non-coating region 1200 is cut. In this case, a step is formed in the central portion in the width direction by the difference between the lengths b1 and b2 on the end face of the non-coated region 1200 constituting each electrode plate 3. And the center part of the length direction of the coating area | region 1100 is cut | disconnected in the cutting line C5 (left side cutting line C5). In this way, each electrode plate 3 is formed by sequentially cutting the electrode plate material 1000. By doing in this way, the non-coating area | region with a level | step difference can be formed in the edge part of each electrode plate 3. FIG. The electrode plate 3 can be applied to a stacked secondary battery in which the positive electrode terminal 30 and the negative electrode terminal 40 are led out in the same direction as the electrode plate 2 formed as shown in FIG. If this electrode plate 3 is used, it will become easy to weld the edge part (non-coating area | region) of a some electrode plate to a terminal.

  Hereinafter, the Example which produced the electrode plate for laminated type secondary batteries of this invention is described.

  As shown in FIG. 4, as an electrode plate material 1000 that is a material of the positive electrode plate 111, a coating region 1100 in which a composite material containing a positive electrode active material (lithium-containing oxide) is coated on both surfaces of an aluminum foil, A strip-shaped material was produced that was intermittently coated such that non-coated regions 1200 on which the material was not coated were alternately arranged continuously in the length direction. In FIG. 4, the length (a) was set to 100 mm, and the length (b) was set to 10 mm.

  Further, as shown in FIG. 4, as an electrode plate material 1000 that is a material of the negative electrode plate 121, a coating region 1100 in which a composite material including a negative electrode active material (carbon-based) is coated on both surfaces of a copper foil, A strip-shaped material was produced that was intermittently coated such that non-coated regions 1200 on which the material was not coated were alternately arranged continuously in the length direction. In FIG. 4, the length (a) was set to 110 mm, and the length (b) was set to 5 mm.

  The central portions of the coating region 1100 and the non-coating region 1200 of each of the positive electrode material 1000 and the negative electrode material 1000 prepared in this way are guillotine along the cutting lines C1 and C2 shown in FIG. Each electrode plate was produced by cutting. Thereafter, as shown in FIG. 1 to FIG. 3, each of the plurality of positive plates 11 and each of the plurality of negative plates 12 are arranged so as to be alternately stacked with each of the plurality of separators 13 interposed therebetween, After the end portions (non-coated region) of the plurality of positive electrode plates 11 are welded to the positive electrode terminal 30 and the end portions (non-coated region) of the plurality of negative electrode plates 12 are welded to the negative electrode terminal 40, By encapsulating, injecting a non-aqueous electrolyte, and charging for the first time, the stacked secondary battery 100 was produced.

  As a result, when producing the electrode plate 1 from the electrode plate material 1000 made of a strip-like material, no disposal cost is required, the production yield can be improved, and the material cost can be reduced. Further, in the conventional electrode plate material 500 as shown in FIG. 7, the number of times of cutting for forming one electrode plate 51 is two, whereas as shown in FIG. Can be formed, and the productivity has been improved.

  It should be considered that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above embodiments and examples but by the scope of claims, and is intended to include all modifications and variations within the meaning and scope equivalent to the scope of claims. .

  Since the manufacturing method of the electrode plate for a laminated secondary battery and the electrode plate material for the laminated type secondary battery of the present invention have a high production yield and productivity, it can be applied, for example, to the production of a lithium ion secondary battery. it can.

  1, 2, 3: electrode plate, 100: stacked secondary battery, 1000: electrode plate material, 1100: coating region, 1200: non-coating region.

Claims (5)

By cutting a band-shaped material in which a coating region where a composite material containing an active material is coated and a non-coating region where a composite material is not coated are alternately arranged in the length direction. In the manufacturing method of the electrode plate for the laminated type secondary battery for manufacturing the plate,
Cutting the central portion in the length direction of the coating region;
And a step of cutting a central portion in the length direction of the non-coating region.   The method for producing an electrode plate for a stacked secondary battery according to claim 1, wherein the length of the coating region of the strip-shaped material is approximately twice the length of the coating region after cutting.   The length of the non-coating area | region of the said strip | belt-shaped material is the double of the length of the said non-coating area | region after a cutting | disconnection, The electrode plate for multilayer secondary batteries of Claim 1 or Claim 2 Production method.   Laminate type secondary material composed of a strip-like material in which a coating region coated with a composite material containing an active material and a non-coated region not coated with a composite material are alternately arranged in the length direction. In the electrode plate material for a battery, the length of the coating region of the strip-shaped material is approximately twice the length of the coating region in the single electrode plate constituting the laminated secondary battery, Electrode plate material for laminated secondary batteries. The length of the non-coating area | region of the said strip | belt-shaped material is a lamination | stacking type | mold secondary of Claim 4 which is substantially twice the length of the non-coating area | region in the single electrode board which comprises a lamination | stacking secondary battery. Battery plate material.

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