JP2010170972A - Positive electrode member, nonaqueous electrolyte battery, and method of manufacturing positive electrode member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive electrode member, which allows manufacturing a nonaqueous electrolyte battery with large capacity. <P>SOLUTION: The positive electrode member includes a first active material layer 2A having a positive electrode active material, a second active material layer 2B having a positive electrode active material and disposed to face the first active material layer 2A, and a positive electrode current collecting layer 1 disposed between the first active material layer 2A and the second active material layer 2B. The positive electrode member 10 is a sintered body in which the first active material layer 2A, the second active material layer 2B and the positive electrode current collecting layer 1 are integrated, and is high in adhesion between the active material layers 2A and 2B and the current collecting layer 1. Therefore, when a lithium ion battery 20 is manufactured using the positive electrode material 10, the increase in internal resistance can be suppressed to increase the capacity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte disposed between the electrodes, a positive electrode member used in the battery, and a method for manufacturing the positive electrode member.

  A nonaqueous electrolyte battery (typically, a lithium ion battery) is used as a power source for a relatively small electric device such as a portable device. A lithium ion battery includes a positive electrode, a negative electrode, and an electrolyte layer disposed between these electrodes. For example, Patent Documents 1 and 2 disclose a non-aqueous electrolyte type using a positive electrode member in which a positive electrode current collecting layer formed mainly of metal is formed on one surface of a positive electrode active material layer which is a sintered body of a lithium composite oxide. A lithium ion battery is disclosed.

JP-A-8-180904 JP 2001-143687 A

  However, the adhesion between the positive electrode active material layer, which is a sintered body of lithium composite oxide, and the positive electrode current collecting layer composed of a metal foil or the like is poor. It was a factor that increased resistance. Therefore, the capacity of the lithium ion battery using such a positive electrode member is suppressed due to the internal resistance.

  Moreover, although the positive electrode current collection layer is a member necessary for the lithium ion battery, it is preferably as thin as possible since it is a member that does not contribute to the capacity of the battery. However, it is difficult to reduce the metal foil used for the positive electrode current collecting layer to a certain thickness (approximately 10 μm) or less because of technical problems. In addition, the thinner the metal foil, the more difficult it is to handle, and even if it can be attached to the surface of the positive electrode active material layer, the adhesion between the active material layer and the current collecting layer is poor, and the inside of the battery Resistance becomes high.

  The present invention has been made in view of the above circumstances, and one of its purposes is to produce a nonaqueous electrolyte battery that secures a discharge capacity by enhancing the adhesion between the positive electrode current collecting layer and the positive electrode active material layer. It is providing the positive electrode member which can do, and its manufacturing method.

  Another object of the present invention is to provide a lithium battery using this positive electrode member.

(1) This invention positive electrode member concerns on the positive electrode member used for a nonaqueous electrolyte battery provided with a positive electrode, a negative electrode, and the nonaqueous electrolyte layer arrange | positioned between these electrodes. The positive electrode member of the present invention includes a first active material layer having a positive electrode active material, a second active material layer having a positive electrode active material and disposed opposite to the first active material layer, and a first active material layer And a positive electrode current collecting layer disposed between the first active material layer and the second active material layer. The positive electrode member of the present invention is characterized in that the first active material layer, the second active material layer, and the positive electrode current collecting layer are integrated by sintering.

  According to the configuration of the positive electrode member of the present invention, since the positive electrode current collecting layer is integrated by sintering in a state of being sandwiched between the first active material layer and the second active material layer, Between the active material layers, an interface layer in which substances constituting both layers are mixed is formed. Therefore, the positive electrode current collecting layer and the active material layer can be reliably adhered, and as a result, the nonaqueous electrolyte battery of the present invention using this positive electrode member becomes a nonaqueous electrolyte battery having a low internal resistance and a large capacity. . In addition, since the positive electrode member has a configuration in which the positive electrode current collecting layer is sandwiched between two active material layers, the positive electrode current collecting layer is shared by the two active material layers. As a result, since the thickness of the positive electrode current collecting layer in the nonaqueous electrolyte battery can be reduced, the capacity per volume of the battery can be increased.

(2) As one form of this invention positive electrode member, it is preferable that the porosity of at least one of a 1st active material layer and a 2nd active material layer is 10% or less. In particular, the porosity of both active material layers is preferably 10% or less.

  In the nonaqueous electrolyte battery, if there is a gap in the active material layer, the gap inhibits diffusion of lithium ions in the active material layer. As a result, the internal resistance of the nonaqueous electrolyte battery is increased, and the capacity of the battery is reduced. On the other hand, when the porosity is 10% or less as described above, the conduction of lithium ions in the active material layer of the positive electrode member is difficult to be inhibited.

(3) As one form of this invention positive electrode member, the positive electrode current collection layer with which a positive electrode member is equipped has an electroconductive substance and a positive electrode active material, and the mixing ratio of an electroconductive substance and a positive electrode active material is mass ratio. 1: 0.05 to 0.3 is preferable.

  When the positive electrode active material is mixed with the positive electrode current collector layer, the adhesion between the positive electrode current collector layer and the active material layer is increased, so that separation between the positive electrode current collector layer and the active material layer accompanying charge / discharge is effectively prevented. be able to. When the mixing ratio is lower than the lower limit, the effect of increasing the adhesion between the current collecting layer and the active material layer is reduced. On the contrary, when the mixing ratio exceeds the upper limit, the conductivity of the current collecting layer is lowered.

(4) When the positive electrode current collecting layer is a mixture of the positive electrode active material and the conductive material, the positive electrode current collecting layer has an amount of the positive electrode active material from the central portion in the thickness direction toward both active material layers. It is preferred to have a graded composition that increases stepwise or continuously.

  According to the said structure, since the electroconductive substance is abundantly contained in the center part of the positive electrode current collection layer, it can be set as the positive electrode current collection layer which has sufficient electroconductivity. In addition, since the positive electrode active material is abundant in the vicinity of the active material layer in the positive electrode current collector layer, the adhesion between the positive electrode current collector layer and the active material layer is high.

(5) As one form of this invention positive electrode member, it is preferable that the thickness of a positive electrode current collection layer is 1-20 micrometers.

  A positive electrode current collecting layer having such a thickness sufficiently exhibits a current collecting function. Here, in the configuration in which the positive electrode current collector layer is formed on one surface of the positive electrode active material layer as in the past, the current collector layer is easily peeled off from the active material layer when the current collector layer is thinned. Since the two active material layers are sandwiched, even if the current collecting layer is thinned, the problem of peeling hardly occurs.

(6) As one form of this invention positive electrode member, it is preferable to provide the positive electrode current collection member electrically connected to a positive electrode current collection layer by the side surface of a positive electrode member.

  When a lithium battery is manufactured using the positive electrode member having such a configuration, a terminal can be drawn from the lithium battery without increasing the thickness of the lithium battery.

(7) As one form of this invention positive electrode member, it is preferable that the positive electrode current collection layer is formed in the net shape which has an opening part.

  When the positive electrode current collector layer is formed in a net shape, a mesh-like opening that penetrates the current collector layer is formed in the thickness direction of the current collector layer. As a result, since the first active material layer and the second active material layer are directly connected through the opening, the adhesion between the layers of the positive electrode member is improved, and separation between the layers hardly occurs.

  The openings can be repeated in a certain pattern. For example, a lattice pattern in which rectangular openings are regularly arranged, or a punching metal-like pattern in which circular openings are regularly arranged can be used. In addition, the opening may be a polygon (for example, a triangle, pentagon, hexagon, etc.), an ellipse, or an indefinite shape such as a cloud. Further, it may be an irregular pattern in which an arbitrary number of openings having at least one of the shapes listed above are selected and arranged appropriately.

(8) As one form of this invention positive electrode member, the radius of the inscribed circle of an opening part when planarly viewing a net-like positive electrode current collection layer is below the thickness of the thicker one of two active material layers preferable.

  When the net-like current collecting layer is formed, an active material having a distance from the current collecting layer is generated at the position of the opening when the current collecting layer is viewed in plan. For example, in the case of a rectangular opening, the active material in the middle position of the opening has a distance from the current collecting layer on either side in the width direction. On the other hand, in the thickness direction of the positive electrode member, the active material located on the surface of the active material layer opposite to the surface in contact with the current collector is originally at a distance from the current collection layer. Therefore, if the radius of the inscribed circle of the opening when the net-like positive electrode current collecting layer is viewed in plan is set to be equal to or smaller than the thickness of the active material layer, the active material farthest from the current collecting layer is It is an active material on the surface. That is, if the opening is defined as described above, an increase in the internal resistance of the positive electrode member due to the opening being formed in the current collecting layer can be suppressed.

(9) The nonaqueous electrolyte battery of the present invention includes the positive electrode member of the present invention and a solid electrolyte layer laminated on the positive electrode member.

  In the nonaqueous electrolyte battery of the present invention having the above configuration, the positive electrode current collecting layer is shared by two active material layers. As a result, since the thickness of the positive electrode current collecting layer in the nonaqueous electrolyte battery can be reduced, the capacity per volume of the battery can be increased.

(10) The method for producing a positive electrode member of the present invention includes the following steps.
The process of forming the molded object which laminated | stacked the positive electrode active material used as a 1st active material layer, the electroconductive powder used as a positive electrode current collection layer, and the positive electrode active material used as a 2nd active material layer.
A step of integrating the molded body by sintering.

  According to the method of the present invention, it is possible to easily form a thin current collecting layer without using a thin metal foil which is difficult to handle. In addition, the positive electrode member of the present invention can be produced, in which an interface layer in which constituent materials of both layers are mixed is easily formed between the current collecting layer and the active material layer, and the adhesiveness between both layers is high.

(11) Moreover, the manufacturing method of this invention positive electrode member is equipped with the following processes, It is characterized by the above-mentioned.
The process of forming the slurry containing the positive electrode active material used as a 1st active material layer in a sheet form.
A step of applying a metal paste to be a positive electrode current collecting layer to the sheet-like molded body.
The process of forming the slurry containing the positive electrode active material used as a 2nd active material layer in a sheet form so that a metal paste may be pinched | interposed between a sheet-like molded object.
The process of sintering the compact in the state where the metal paste is sandwiched.

  According to the method of the present invention, it is possible to easily form a thin current collecting layer without using a thin metal foil which is difficult to handle. Moreover, the said interface layer is easy to be formed between a current collection layer and an active material layer, and this invention positive electrode member with high adhesiveness of both layers can be manufactured.

(12) In the step of applying the metal paste, the metal paste can be formed into a net-like pattern.

  The positive electrode current collecting layer formed in a net shape has a net-like opening that penetrates the current collecting layer in the thickness direction of the current collecting layer, so that the first active material layer and the second active material layer are formed through the opening. The positive electrode member in a state in which are directly connected can be manufactured. Each layer of such a positive electrode member is bonded with high adhesion as described above.

  According to the configuration of the present invention, since the positive electrode current collecting layer is sandwiched between the first active material layer and the second active material layer, the adhesion between the positive electrode current collecting layer and the active material layer is improved. It is possible to prevent both layers from peeling off easily. Therefore, when a nonaqueous electrolyte battery is produced using this positive electrode member, a battery having a low internal resistance and a high discharge capacity can be obtained. Further, when a non-aqueous electrolyte battery is manufactured using this positive electrode member, one positive current collecting layer is shared by two active material layers, and the proportion of the positive current collecting layer in the non-aqueous electrolyte battery is reduced. Therefore, the capacity per volume of the battery can be increased.

(A) is a schematic block diagram of this invention positive electrode member, (B) is a schematic block diagram of this invention nonaqueous electrolyte battery which uses the positive electrode member of (A). Moreover, (C) is a schematic block diagram of this invention nonaqueous electrolyte battery comprised by laminating | stacking two or more nonaqueous electrolyte batteries of (B). It is explanatory drawing about the manufacturing method of the positive electrode member which concerns on Example 2, Comprising: (A) is a perspective view of a green sheet, (B) is a top view of a green sheet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1A is a schematic configuration diagram of a positive electrode member of the present invention, and FIG. 1B is a schematic configuration diagram of an all solid-state lithium ion battery (non-aqueous electrolyte battery) using the positive electrode member of FIG. FIG. 1C is a schematic configuration diagram of a lithium ion battery formed by stacking a plurality of the lithium ion batteries of FIG. First, the configuration of the positive electrode member will be described in detail, and then the configuration of a lithium ion battery using the positive electrode member will be described.

<Positive electrode member>
The positive electrode member 10 includes a first active material layer 2A and a second active material layer 2B containing a positive electrode active material, and a positive electrode current collecting layer 1 disposed between the active material layers 2A and 2B. These layers 2A, 1 and 2B are integrated by sintering as will be described later. The thickness of the positive electrode member 10 is preferably 20 to 300 μm.

As the active material contained in the first active material layer 2A and the second active material layer 2B, LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ etc. can be mentioned. These active material layers 2 may contain a conductive additive such as carbon black.

  The porosity of these active material layers 2A and 2B is preferably 10% or less. If the porosity is 10% or less, the lithium ion conductivity of the active material layers 2A and 2B can be sufficiently secured. The thickness of each active material layer 2A, 2B may be 9.5 to 149.5 μm. A preferable thickness of these layers 2A and 2B is 40 to 100 μm.

  The positive electrode current collecting layer 1 can be composed of a metal or a conductive metal oxide. For example, Cu, Ni, Pd, Ag or the like can be used as the metal. Examples of the metal oxide include ITO (Indium Tin Oxide) and ZnO. Moreover, the thickness of the current collection layer 1 is 1-100 micrometers, Preferably it is good to set it as the range of 1-20 micrometers. By setting it as the thickness of this range, it can be set as the current collection layer 1 which has sufficient current collection function.

  The positive electrode current collecting layer 1 may be a mixed layer of a conductive material and a positive electrode active material. When the current collecting layer 1 is a mixed layer, the adhesion between the positive electrode current collecting layer 1 and the active material layers 2A and 2B increases. The mixing ratio of the positive electrode active material and the conductive material is preferably a mass ratio, with the positive electrode active material being 1 and the conductive material being 0.05 to 0.3. When the mixing ratio is in the above range, both the conductivity of the positive electrode current collecting layer 1 and the adhesion of the positive electrode current collecting layer 1 to the active material layers 2A and 2B can be reliably ensured.

  Further, when the current collecting layer 1 is a mixed layer, the amount of the active material increases stepwise or continuously from the central portion in the thickness direction toward both the active material layers 2A and 2B. It preferably has a gradient composition. When the current collecting layer 1 has a gradient composition, the adhesion between the current collecting layer 1 and the two active material layers 2A and 2B can be further increased, and the conductivity of the current collecting layer 1 can be sufficiently secured. it can. You may make it the center part of the thickness direction of the positive electrode current collection layer 1 consist only of an electroconductive substance substantially. That is, the current collecting layer 1 may have a structure in which a mixed layer, a layer made of only a conductive material, and a mixed layer are stacked in this order.

  To produce the positive electrode member 10 having the above-described configuration, typically, a pressure sintering method or a green sheet method can be used.

  In order to produce the positive electrode member 10 by the pressure sintering method, for example, the following may be performed. First, the positive electrode active material powder that becomes the first active material layer, the conductive powder that becomes the current collecting layer, and the positive electrode active material powder that becomes the second active material layer are arranged on the mold so as to form layers. And after pressing the powder arrange | positioned to the metal mold | die in layers, this press-molded body should just sinter. If the pressure sintering method is used, it is easy to make the positive electrode current collecting layer 1 have a gradient composition. Specifically, the layer before pressurization that becomes the current collecting layer may be a mixed powder of the positive electrode active material powder and the conductive powder. Moreover, the ratio of the active material powder and the conductive powder can be easily changed in the thickness direction of the mixed powder layer.

  On the other hand, in order to produce the positive electrode member by the green sheet method (for example, using a doctor blade device), for example, the following may be performed. First, an active material mixed slurry in which a positive electrode active material powder and a binder are mixed is prepared, and a sheet-like molded body is manufactured using this slurry. Next, a metal paste in which a metal powder is dispersed in a solvent is applied onto the sheet-like molded body. Furthermore, another active material mixed slurry is applied on the metal paste. And the laminated body of this 3 layer structure is sintered, and a positive electrode member is completed.

  Here, in the step of applying the metal paste, it can be applied to a net-like pattern. For example, the metal paste may be printed in a net shape by a screen printing method or the like. When the positive electrode current collecting layer having a net pattern is formed, the first active material layer and the second active material layer are directly connected to each other at an opening (mesh) that penetrates the current collecting layer in the thickness direction of the current collecting layer. Therefore, a positive electrode member having high adhesion between layers can be manufactured. The shape of the opening is not particularly limited, and may be, for example, a polygon or an ellipse, or an indefinite shape such as a cloud shape. Further, by setting the radius of the inscribed circle of the opening in the positive electrode current collecting layer to be equal to or smaller than the thicker one of the first active material layer and the second active material layer, the internal resistance of the positive electrode member due to the opening is increased Can be suppressed.

Whichever method is used, the two active material layers and the one positive electrode current collecting layer are integrated by sintering. The sintering conditions may be appropriately selected depending on the materials of both layers, but are generally 600 to 1000 ° C. × 2 to 24 hours. For example, if the positive electrode active material is LiCoO ₂ and the positive electrode current collecting layer is Ag, the sintering condition is preferably 800 to 950 ° C. × 2 to 12 h.

<All solid lithium battery>
Solid electrolyte layers (SE layers) 3A and 3B are laminated on the front and back surfaces of the positive electrode member 10 described above, and negative electrode layers 4A and 4B are laminated on the SE layers 3A and 3B, respectively. A lithium battery 20 can be manufactured (see FIG. 1B).

The SE layers 3A and 3B are, for example, Li—P—O—N, Li—P—S—O, Li—P—S composed of Li ₂ S and P ₂ S ₅ , Li—La—Ti—O. Li-La-Zr-O amorphous film or polycrystalline film can be used. The thickness of the SE layers 3A and 3B is preferably about 1 to 10 μm. The SE layers 3A and 3B can be formed by using a solid phase method (powder sintering method) or a gas phase method (for example, PVD method or CVD method).

  As the negative electrode layers 4A and 4B, for example, one selected from the group consisting of Li metal and an element capable of forming an alloy with Li metal, or a mixture or alloy thereof can be preferably used. Examples of elements that can form an alloy with Li include Al, Si, Sn, Bi, In, and Ag. The negative electrode layers 4A and 4B can have a function as a current collecting layer in the negative electrode layer itself. The thickness of the negative electrode layers 4A and 4B is preferably about 0.5 to 50 μm. A vapor phase method can be used for forming the negative electrode layers 4A and 4B.

  In addition, the lithium ion battery 20 may be provided with the positive electrode current collecting member 1C on the side surface. More specifically, the positive electrode current collecting member 1 </ b> C is electrically connected to the positive electrode current collecting layer 1 on the side surface of the positive electrode member 10 in the battery 20. In the positive electrode member 10 of the present invention, since the current collecting layer 1 is sandwiched between the active material layers 2A and 2B, it is difficult to arrange a terminal for connecting the current collecting layer 1 to the outside. This is because the current collecting layer 1 is exposed only on the side surface of the battery 20. Further, when a lead wire or the like is pulled out from the current collecting layer 1 and a terminal is connected, the lead wire may come into contact with the negative electrode layers 4A and 4B exposed on the side surface of the battery 20, and the positive and negative electrodes may be short-circuited. On the other hand, since the positive electrode current collecting member 1C is disposed so as to protrude from the side surface of the positive electrode member 10, it is easy to connect a terminal to the positive electrode current collecting member 1C. Moreover, when laminating | stacking the battery 20 so that it may mention later, the positive electrode current collection layers 1 can be connected, without the positive electrode and negative electrode of each battery 20 short-circuiting. Since the positive electrode current collecting member 1C is not arranged in the thickness direction of the battery 20, the current collecting member 1C does not increase the thickness of the battery 20. The positive electrode current collector 1C can be formed, for example, by mixing a conductive material such as carbon powder, carbon fiber, or Ni powder and a resin material such as an epoxy resin, and applying and curing the mixture on the side surface of the positive electrode member 10. .

  On the other hand, since the two negative electrode layers 4A and 4B included in the lithium ion battery 20 exist on the front and back of the battery 20, the terminals may be connected to the negative electrode layers 4A and 4B as they are through the conductive wires.

  A plurality of lithium ion batteries 20 shown in FIG. 1B may be stacked to form a lithium ion battery 30 as shown in FIG. In this case, the positive electrode current collecting member 1C of each positive electrode member 10 is preferably connected by the positive electrode collecting terminal P, and each positive electrode member 10 is electrically connected. Further, in order to electrically connect the negative electrode layers 4A and 4B of the battery 30, the negative electrode current collecting member 4C connected to the negative electrode layers 4A and 4B may be connected by the negative electrode collecting terminal N. At this time, each negative electrode current collecting member 4C protrudes only on the opposite side to the positive electrode current collecting member 1C, and the negative electrode collecting terminal N and the above-described positive electrode collecting terminal P are pulled out to the opposite sides, whereby the terminal P And the terminal N can be reliably prevented.

  The number of stacked lithium ion batteries 20 can be selected as appropriate according to the use of the lithium ion battery 30.

  An all-solid lithium battery 30 having a laminated structure as shown in FIG. 1C was produced, and the capacity was measured. In addition, as a comparative example, a lithium battery using a non-aqueous electrolyte was produced and its capacity was measured.

<Example>
5 g of LiCoO ₂ having a particle size of 2 μm and 1.3 g of a binder (DB17 manufactured by Yuken Kogyo Co., Ltd.) were prepared and kneaded to form a sheet. A layer made of Ag particles having a particle diameter of 2 μm was formed on one surface of the sheet by a screen printing method, and the kneaded material layer was further formed on the layer. Then, the laminated body was subjected to a heat treatment at 950 ° C. for 4 hours to produce the positive electrode member 10. The heat-treated kneaded material layer became the first active material layer 2A and the second active material layer 2B, and the thickness of each layer was 25 μm. Further, the heat-treated layer of Ag particles was the positive electrode current collecting layer 1 and had a thickness of 10 μm.

  When the porosity of the active material layers 2A and 2B of the positive electrode member 10 was measured, it was 8%. The porosity was measured by comparing the density of the produced active material layers 2A and 2B with the theoretical density of the raw material. The porosity was also confirmed by observing the active material layers 2A and 2B under a microscope and measuring the area ratio of the voids in the field of view.

Next, SE layers 3A and 3B made of Li ₂ S—P ₂ S ₅ were formed on the front and back surfaces of the positive electrode member 10 by a pulse laser deposition method. The thickness of the SE layers 3A and 3B was 5 μm.

  Next, negative electrode layers 4A and 4B made of Li metal were formed on the surfaces of the SE layers 3A and 3B by a resistance heating vapor deposition method. The thickness of the negative electrode layers 4A and 4B was 19 μm.

  Further, the positive electrode current collecting member 1 </ b> C was formed on the side surface of the positive electrode member 10. The positive electrode current collector 1C was formed by applying D753 manufactured by Fujikura Kasei Co., Ltd. on the side surface of the positive electrode member 10 so as not to contact the SE layers 3A and 3B and curing.

  The positive electrode current collecting layer 1, the active material layers 2A and 2B, the SE layers 3A and 3B, the negative electrode layers 4A and 4B, and the positive electrode current collecting member 1C as described above are formed as a unit, and 10 unit members are laminated. The lithium battery of Example 1 was completed. Between the unit members, a negative electrode current collecting member 4C made of a Cu foil having a thickness of 10 μm is disposed. Further, the negative electrode current collecting member 4C is also disposed on the negative electrode layer 4B exposed on the upper surface of the laminate and the negative electrode layer 4A exposed on the lower surface.

  Finally, the positive electrode current collecting members 1C of the unit members are electrically connected by the positive electrode collecting terminal P, and the negative electrode collecting members 4C are electrically connected by the negative electrode collecting terminal N.

  The dimensions of the lithium-ion battery 30 having a laminated structure formed as described above were 55 mm × 35.5 mm × 3.0 mm. Moreover, it was 920 mAh when the discharge capacity of the battery was measured. By obtaining such a discharge capacity, it was found that even a thin current collecting layer functions as a current collecting layer. Moreover, the discharge capacity was higher than that of a general lithium ion battery having the same volume.

<Example 2>
In Example 2, an example of producing the positive electrode member of the present invention by the green sheet method will be described with reference to FIG.

First, LiCoO ₂ powder was prepared as a positive electrode active material. This LiCoO ₂ powder is mixed with polyvinyl butyral (PVB), dibutyl phthalate (DBP), and toluene to prepare a slurry. And the slurry was shape | molded in the sheet form with coating equipment, such as a doctor blade apparatus, and the green sheet 7A was obtained. LiCoO ₂ : PVB: DBP: toluene was 40: 1: 1: 10 by weight. Further, the thickness t of the green sheet 7A set by the doctor blade device was 75 μm.

  Next, the metal paste 8 was formed into a mesh pattern on the above-described green sheet 7A by screen printing. The thickness of the mesh pattern metal paste 8 was 12 μm in the print setting. The green sheet 7A is exposed from the opening 8h, which is a portion where the metal paste 8 is not formed. The mesh opening 8h in this example is square, and its width d is set to be not more than twice the thickness t of the green sheet 7A. That is, the radius of the inscribed circle in the square opening 8h is set to be equal to or less than the thickness t of the green sheet 7A. By setting in this way, since the electron conduction distance is limited to t, an increase in internal resistance in the positive electrode member 11 can be suppressed.

  Next, the above-mentioned slurry is further coated on the mesh pattern to form a green sheet 7B (the same thickness t as the first green sheet) and pressed at a mold temperature of 50 ° C. and 40 MPa. A laminated body in which the upper and lower green sheets 7A and 7B and the metal paste layer 8 were integrated was produced.

  Finally, the laminate was heat-treated at 600 ° C. for 5 hours in the air atmosphere to remove the binder contained in the slurry, and then sintered at 1000 ° C. for 3 hours to obtain the positive electrode member 11. By sintering, the green sheets 7A and 7B become active material layers, and the metal paste 8 becomes a positive electrode current collecting layer.

  The positive electrode member 11 is sintered in a state in which the two active material layers 7A and 7B sandwiching the positive electrode current collector layer are directly connected to each other because the opening 8h is formed in the positive electrode current collector layer 8. For this reason, the adhesion between the respective layers of the positive electrode member 11 is increased. Therefore, when a battery is manufactured using the positive electrode member 11, the layers 7A, 7B, 8 are not easily peeled off due to charging / discharging of the battery.

  In addition, when producing a battery using the positive electrode member, an SE layer and a negative electrode layer were formed in the same manner as in Example 1 to produce a battery.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention.

  The positive electrode member of the present invention can be suitably used for the production of a high-capacity nonaqueous electrolyte battery. The nonaqueous electrolyte battery of the present invention can be suitably used as a power source for portable devices and the like.

10, 11 Positive electrode member 20, 30 Lithium ion battery (non-aqueous electrolyte battery)
DESCRIPTION OF SYMBOLS 1 Positive electrode current collection layer 1C Positive electrode current collection member 2A 1st active material layer 2B 2nd active material layer 3A, 3B Solid electrolyte layer (SE layer)
4A, 4B Negative electrode layer 4C Negative electrode current collecting member P Collective terminal for positive electrode N Collective terminal for negative electrode 7A, 7B Green sheet (active material layer)
8 Metal paste (positive electrode current collecting layer) 8h Opening

Claims (12)

A positive electrode member used for a non-aqueous electrolyte battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte layer disposed between the electrodes,
A first active material layer having a positive electrode active material;
A second active material layer having a positive electrode active material and disposed opposite the first active material layer;
A positive electrode current collecting layer disposed between the first active material layer and the second active material layer;
A positive electrode member, wherein the first active material layer, the second active material layer, and the positive electrode current collecting layer are integrated by sintering.   The positive electrode member according to claim 1, wherein the porosity of at least one of the first active material layer and the second active material layer is 10% or less. The positive electrode current collecting layer has a conductive material and a positive electrode active material,
The positive electrode member according to claim 1 or 2, wherein a mixing ratio of the conductive material and the positive electrode active material is 1: 0.05 to 0.3 in terms of mass ratio.   The positive electrode current collecting layer has a graded composition in which the amount of the positive electrode active material increases stepwise or continuously from the center in the thickness direction toward both active material layers. Positive electrode member.   The positive electrode member according to claim 1, wherein the positive electrode current collecting layer has a thickness of 1 to 20 μm.   The positive electrode member according to any one of claims 1 to 5, further comprising a positive electrode current collector member electrically connected to the positive electrode current collector layer on a side surface of the positive electrode member.   The positive electrode member according to claim 1, wherein the positive electrode current collecting layer is formed in a net shape having an opening.   The positive electrode member according to claim 7, wherein the radius of the inscribed circle of the opening when the net-like positive electrode current collecting layer is viewed in plan is equal to or less than the thickness of the thicker of the two active material layers. The positive electrode member according to any one of claims 1 to 8,
A solid electrolyte layer laminated on the positive electrode member;
A non-aqueous electrolyte battery comprising: A first active material layer having a positive electrode active material;
A second active material layer having a positive electrode active material and disposed opposite the first active material layer;
A method for producing a positive electrode member comprising a positive electrode current collecting layer disposed between a first active material layer and a second active material layer,
Forming a molded body in which a positive electrode active material to be a first active material layer, a conductive powder to be a positive electrode current collecting layer, and a positive electrode active material to be a second active material layer;
Integrating the molded body by sintering; and
The manufacturing method of the positive electrode member characterized by comprising. A first active material layer having a positive electrode active material;
A second active material layer having a positive electrode active material and disposed opposite the first active material layer;
A method for producing a positive electrode member comprising a positive electrode current collecting layer disposed between a first active material layer and a second active material layer,
Forming a slurry containing a positive electrode active material to be a first active material layer into a sheet;
A step of applying a metal paste to be a positive electrode current collecting layer to the sheet-like molded body;
Forming a slurry containing a positive electrode active material to be a second active material layer in a sheet form so that a metal paste is sandwiched between the sheet-shaped formed body; and
A step of sintering the compact in a state of sandwiching the metal paste;
The manufacturing method of the positive electrode member characterized by comprising.   The method for producing a positive electrode member according to claim 11, wherein in the step of applying the metal paste, the metal paste is formed into a net-like pattern.

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