JP2011187395A - Negative plate for nonaqueous electrolyte secondary battery, manufacturing method of negative plate for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve in adhesion of a negative electrode collector and a negative electrode active material and control diffusion of a component of the negative electrode collector and the negative electrode active material, so that a cycle characteristic is improved, in a nonaqueous electrolyte secondary battery carrying the negative electrode active material of a simple substance of silicon or tin, or a compound including silicon or tin and oxygen, as the negative electrode active material. <P>SOLUTION: Metal foil is used as the negative electrode collector 11. An element which has a stronger tendency to form oxide than a main component of the metal foil and which, furthermore, has a rapid diffusion coefficient in the metal foil is added to the metal foil, and a negative electrode active material layer 12 is formed under an oxidizing atmosphere, so that an oxide layer 13 is formed in which the added element of the negative electrode collector 11 and the negative electrode active material layer 12 are combined, and which has a function improving adhesion of the negative electrode collector 11 and the negative electrode active material layer 12 and preventing the diffusion of the component of the negative electrode collector 11 and the negative electrode active material layer 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a negative electrode plate for a nonaqueous electrolyte secondary battery, a method for producing the negative electrode plate for the nonaqueous electrolyte secondary battery, and a nonaqueous electrolyte secondary battery using the same.

  In recent years, as mobile devices have higher performance and more functions, there is a demand for higher capacities of secondary batteries serving as power sources thereof. As a secondary battery that can satisfy this requirement, a lithium ion secondary battery that represents a non-aqueous electrolyte secondary battery has attracted attention. Conventionally, a negative electrode active material in a lithium ion secondary battery is composed of a material capable of reversibly occluding and releasing lithium ions, and currently, graphite is mainly used. However, there is a demand for a negative electrode active material having a theoretical capacity density as small as 372 mAh / g and a large discharge capacity.

  As the host structure of the negative electrode active material of this lithium ion secondary battery, it has a site that can accept a large amount of lithium ions with a small molecular weight, that lithium ions can easily diffuse in the structure, and the negative electrode active material is as chemically as possible. It is required to be stable and less toxic and inexpensive, to be as easy as possible to produce and synthesize a negative electrode active material, and to have excellent cycle characteristics.

Therefore, an alloy-based active material using silicon, tin, or the like has been tried as a material satisfying the above-described negative electrode active material conditions. It is known that silicon forms a compound of Li _4.4 Si (Li ₂₂ Si ₅ ) by a battery reaction with lithium and has a theoretical capacity density of about 4000 mAh / g, and tin has a battery capacity reaction with lithium. It is known to form a compound of Li _4.4 Sn (Li ₂₂ Sn ₅ ) and to have a theoretical capacity density of about 1000 mAh / g. Among them, for example, a high-capacity negative electrode plate obtained by forming a silicon thin film on a negative electrode current collector by sputtering, CVD, vacuum deposition or thermal spraying has been proposed (for example, Patent Document 1).

  However, when lithium ions are occluded in the battery reaction, the volume expansion of silicon is about 4 times and that of tin is about 5 times. Therefore, the expansion and contraction due to repeated charge and discharge causes the expansion and contraction between the negative electrode active material and the negative electrode current collector. There are problems such as peeling, and sufficient charge / discharge cycle characteristics cannot be obtained. On the other hand, when silicon oxide is used as the negative electrode active material, attention is paid to the fact that the expansion coefficient of the negative electrode active material accompanying charge / discharge changes depending on the oxygen content in the silicon oxide. It has been proposed to increase the oxygen concentration in the vicinity of the electric body higher than the average oxygen concentration of the negative electrode active material layer. According to this configuration, since the expansion of the negative electrode active material layer in the vicinity of the negative electrode current collector can be suppressed, the deformation of the negative electrode plate due to the expansion and contraction of the negative electrode active material layer can be suppressed (for example, see Patent Document 2). .

  Further, by forming an intermediate layer between the negative electrode current collector and the negative electrode active material layer, adhesion between the negative electrode current collector and the negative electrode active material layer is improved, and the negative electrode current collector is changed to the negative electrode active material layer. It has been proposed to prevent delamination. Among them, for example, a configuration is proposed in which an intermediate layer containing molybdenum (Mo) or tungsten (W) is provided between the negative electrode current collector and the negative electrode active material layer (see, for example, Patent Document 3). .

Republished 01/029912 JP 2006-107912 A Japanese Patent No. 4082922

  However, in the configuration disclosed in Patent Document 2, expansion of the negative electrode active material layer during charge / discharge is suppressed by increasing the average oxygen concentration of the negative electrode active material layer in the vicinity of the negative electrode current collector. In the case of a negative electrode active material containing an oxide, the adhesive strength with a copper foil used as a negative electrode current collector is weak, and peeling of the negative electrode active material is likely to occur. Further, in the configuration disclosed in Patent Document 3, although the adhesion between the negative electrode current collector and the negative electrode active material layer is improved by providing an intermediate layer, the diffusion of the components of the negative electrode current collector and the negative electrode active material is prevented. Since it is not an intermediate layer, when charging and discharging are repeated, the components of the negative electrode current collector diffuse not only to the interface between the negative electrode current collector and the negative electrode active material layer but also to the inside of the negative electrode active material layer to form an alloy. There is a problem that the amount of the negative electrode active material that contributes to the decrease in capacity decreases.

  The present invention has been made in view of the conventional problems, and by improving the adhesion between the negative electrode current collector and the negative electrode active material layer and suppressing the diffusion of the negative electrode current collector component and the negative electrode active material, The object is to improve the cycle characteristics of the water electrolyte secondary battery.

  In order to achieve the above object, a negative electrode plate for a non-aqueous electrolyte secondary battery according to the present invention comprises a negative electrode active material comprising silicon or tin alone or a compound containing silicon or tin and oxygen on the surface of a negative electrode current collector made of metal foil. An anode plate for a non-aqueous secondary battery carrying a substance, wherein an element contained in a metal foil of a negative electrode current collector is diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material layer A layer is formed.

  According to the negative electrode plate for a nonaqueous electrolyte secondary battery of the present invention, when the negative electrode active material is formed in an oxidizing atmosphere, the element added to the metal foil of the negative electrode current collector is preferentially the surface of the negative electrode current collector. Since the oxide layer is formed between the current collector component and the negative electrode active material layer by being diffused into the current collector, the adhesion between the negative electrode current collector and the negative electrode active material layer is improved. In addition, since this oxide layer has a high oxygen concentration and does not easily store lithium ions, it is possible to reduce the influence of volume change associated with charge and discharge and to suppress peeling of the negative electrode active material.

  Furthermore, since this oxide layer functions as a barrier layer that prevents the main component of the negative electrode current collector from diffusing into the negative electrode active material layer, the negative electrode that is the main component of the metal foil of the negative electrode current collector even after repeated charge and discharge It is possible to prevent a decrease in the amount of the negative electrode active material that contributes to charge and discharge by preventing diffusion to the active material layer. As a result, the negative electrode plate for a non-aqueous electrolyte secondary battery according to the present invention is used for an electrochemical element such as a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery or an electrochemical capacitor, thereby improving charge / discharge cycle characteristics. be able to.

Sectional drawing of the negative electrode plate for nonaqueous electrolyte secondary batteries of one embodiment in this invention The schematic diagram for demonstrating the manufacturing method of the negative electrode plate for nonaqueous electrolyte secondary batteries of one Embodiment in this invention. 1 is a partially cutaway perspective view of a lithium ion secondary battery according to an embodiment of the present invention. Sectional drawing of the negative electrode plate for nonaqueous electrolyte secondary batteries of another one Embodiment in this invention The schematic diagram for demonstrating the manufacturing method of the negative electrode plate for nonaqueous electrolyte secondary batteries of another embodiment in this invention. Cross-sectional view of negative electrode plate in the prior art Cross-sectional view of another negative electrode plate in the prior art

  In the first aspect of the present invention, for a non-aqueous secondary battery in which a negative electrode current collector made of metal foil is supported on a surface of a negative electrode current collector made of a metal foil, or a negative electrode active material made of a compound containing silicon or tin and oxygen. A negative electrode current collector is formed by forming an oxide layer in which an element contained in a metal foil of a negative electrode current collector is diffused in a negative electrode active material at an interface between the negative electrode current collector and the negative electrode active material layer By improving the adhesion between the negative electrode active material layer and the negative electrode active material layer, peeling of the negative electrode active material can be suppressed.

  In the second invention of the present invention, the element contained in the metal foil of the negative electrode current collector is an element that has a stronger tendency to form an oxide than the main component of the metal foil and has a high diffusion rate in the metal foil. By forming an oxide layer in which an element contained in the metal foil of the negative electrode current collector is diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material layer, the components of the negative electrode current collector and the negative electrode The diffusion of the active material can be suppressed.

  In the third aspect of the present invention, the main component of the metal foil of the negative electrode current collector is copper, and the element contained in the metal foil is at least one of Mn, Nb, Zr, Cr, V, Tc, and Rc. By forming an oxide layer in which an element contained in the metal foil of the negative electrode current collector is diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material layer, the negative electrode active material is peeled off. And the diffusion of the negative electrode current collector component and the negative electrode active material can be suppressed.

  In the fourth invention of the present invention, a large number of irregularities are formed on the surface of the metal foil carrying the negative electrode active material as the negative electrode current collector, so that the negative electrode active material layers are adjacent to each other when forming the negative electrode active material layer. It is possible to form voids in the substrate, and separation of the negative electrode active material can be suppressed by securing a void that suppresses contact due to lateral expansion of the negative electrode active material layer during charging.

  In the fifth invention of the present invention, a negative electrode current collector made of a metal foil containing an element having a strong tendency to form an oxide and having a high diffusion rate in the metal foil is obtained by combining silicon or tin with oxygen in an oxygen atmosphere. A negative electrode active material made of a compound is formed, and an element contained in the metal foil of the negative electrode current collector is diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material by a thermal reaction during the film formation. Thus, the oxide layer can be formed by a simple method.

  In the sixth aspect of the present invention, a negative electrode current collector made of a metal foil containing an element having a strong oxide formation tendency and a fast diffusion coefficient in the metal foil is prepared by using silicon or tin and oxygen in an oxygen atmosphere. After the negative electrode active material made of a compound is formed, heat treatment is performed to diffuse the elements contained in the metal foil of the negative electrode current collector into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material. The formation of the oxide layer can be promoted more than when no heat treatment is performed.

  In a seventh aspect of the present invention, a positive electrode plate having a positive electrode active material formed on the surface of the positive electrode current collector and a negative electrode plate having a negative electrode active material formed on the surface of the negative electrode current collector are interposed via a porous insulating layer. In a non-aqueous electrolyte secondary battery in which an electrode group formed by winding or stacking is enclosed in a battery case together with a non-aqueous electrolyte, the non-aqueous electrolyte secondary according to any one of the first to fourth aspects of the invention as a negative electrode plate By using the negative electrode plate for a battery, cycle characteristics can be improved.

  Next, embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a negative electrode plate according to an embodiment of the present invention. The negative electrode plate 10 includes, for example, a negative electrode current collector 11, a negative electrode active material layer 12 provided on the negative electrode current collector 11, and an oxide layer 13 provided between the negative electrode current collector 11 and the negative electrode active material layer 12. have. The oxide layer 13 covers the whole surface or a part of the negative electrode current collector 11, and the negative electrode active material layer 12 is formed on the oxide layer 13. The negative electrode active material layer 12 and the oxide layer 13 may be formed on both surfaces of the negative electrode current collector 11 or may be formed only on one surface.

  The negative electrode current collector 11 has a highly conductive metal foil mainly composed of at least one metal element that does not form an intermetallic compound with lithium, and has a stronger tendency to form an oxide than the main component. In the main component, at least one element having a high diffusion rate is added. When lithium and an intermetallic compound are formed, they expand and contract with charge / discharge, structural breakdown occurs, current collection performance decreases, and the ability to hold the negative electrode active material layer 12 decreases and the negative electrode active material layer 12 This is because it becomes easy to drop off from the negative electrode current collector 11. As an additive element to be added to the metal foil, for example, when the main component of the metal foil of the negative electrode current collector is copper, at least one of Mn, Nb, Zr, Cr, V, Tc, and Rc is desirable. desirable.

  The oxide layer 13 is formed by forming the negative electrode active material layer 12 in an oxidizing atmosphere. That is, when the negative electrode active material is formed in an oxidizing atmosphere, first, an additive element having a strong oxide formation tendency in the negative electrode current collector 11 is preferentially diffused on the surface of the negative electrode current collector 11. The additive element diffused on the surface of the negative electrode current collector 11 and the oxide of the negative electrode active material form the oxide layer 13. In order to promote the formation of the oxide layer 13, heat treatment may be performed in an oxidizing atmosphere.

The negative electrode active material layer 12 includes, for example, at least one selected from the group consisting of a single element, an alloy, and a compound capable of forming an alloy with lithium as a negative electrode active material. Among them, the negative electrode active material is represented by a simple substance of silicon, a silicon oxide represented by a general formula SiO _x (0 <x ≦ 2), or a simple substance of tin, a general formula SnO _y (0 <y ≦ 2). It is preferable to include at least one member selected from the group consisting of tin oxides. Further, when the average value of the oxygen amount when viewed from the whole negative electrode active material layer 12 is O _av12 and the average value of the oxygen amount when viewed from the whole oxide layer 13 is O _M13 , the relationship of O _M13 > O _av12 is obtained. be satisfied. By _making the relationship O _M13 > O _av12 , it is possible to suppress expansion of the oxide layer 13 due to occlusion of lithium during charging, and it is possible to suppress separation of the oxide layer 13 and the negative electrode active material layer 12. .

The negative electrode active material layer 12 is preferably formed by at least one method selected from the group consisting of a vapor deposition method, a sputtering method, a CVD method, and a sintering method, for example. Here, in order to satisfy the relationship of O _M13 > O _av12 , for example, in the vapor deposition method, it is possible to _satisfy O _M13 > O _av12 by changing the oxygen concentration of the atmospheric gas. That is, the oxygen concentration in the atmospheric gas is decreased with time, or the oxygen concentration C1 is set from the start of formation of the negative electrode active material layer 12 to a predetermined time, and thereafter, the concentration C2 is lower than C1. Can be formed.

  For this negative electrode plate 10, a negative electrode current collector 11 made of, for example, a metal foil is prepared, and silicon and oxygen are supplied to the surface of the negative electrode current collector 11 using a vapor deposition apparatus as shown in FIG. It can be carried out by depositing silicon oxide having a composition or silicon simple substance. The vapor deposition apparatus 50 shown in FIG. 2 includes a vacuum chamber 76 and an exhaust pump 77 for exhausting the vacuum chamber 76. Inside the vacuum chamber 76 are an unwinding roller 51 and a winding roller 52 that hold the negative electrode current collector 11, a traveling roller 53 and a traveling roller 54, a cooling roller 55, and an oxygen nozzle for emitting oxygen gas. 64, a silicon raw material 73 that is an evaporation source for supplying silicon, an evaporation crucible 74 that holds the silicon raw material 73, and an electron irradiation unit 75 for evaporating the silicon raw material 73. The oxygen nozzle 64 is connected to an oxygen flow rate control unit 65 and an oxygen cylinder (not shown) via a pipe.

In addition, a shielding plate 59 is provided inside the vacuum chamber 76, and oxygen emitted from the oxygen nozzle 64 and silicon evaporated from the silicon raw material 73 are placed on the cooling roller 55 through the gap of the shielding plate 59. The surface of the negative electrode current collector 11 is supplied from the normal direction of the negative electrode current collector 11. A region defined by a gap between the shielding plates 59 and supplied with oxygen and silicon on the surface of the negative electrode current collector 11 is referred to as a negative electrode active material forming region 70.

  A method of forming the negative electrode plate 10 using such a vapor deposition apparatus 50 will be described below. The negative electrode current collector 11 made of metal foil is placed on the unwinding roller 51, and the vacuum chamber 76 is evacuated by the vacuum evacuation pump 77. When the vacuum degree of the vacuum chamber 76 reaches a predetermined vacuum level, the negative electrode current collector 11 is caused to travel along the cooling roller 55 from the unwinding roller 51 through the traveling roller 53 while exhausting the vacuum chamber 76. Meanwhile, the silicon raw material 73 contained in the evaporation crucible 74 is irradiated with electrons from the electron irradiation unit 75 to melt and evaporate silicon. The evaporation amount of silicon is controlled by using a film thickness controller (not shown) connected to the film thickness monitor 63. At the same time, a predetermined amount of oxygen is introduced from the oxygen nozzle 64 into the vacuum chamber 76. The oxygen flow rate is controlled by the oxygen flow rate control unit 65.

  Silicon and oxygen pass through the gap of the shielding plate 59 and are supplied to the surface of the negative electrode current collector 11 running on the cooling roller 55 in the negative electrode active material layer forming region 70. In the active material layer forming region 70, silicon oxide or silicon simple substance is incident and deposited on the traveling negative electrode current collector 11 from the normal direction. When silicon oxide is deposited on the negative electrode current collector 11, silicon oxide, oxygen, and additive elements diffused on the surface of the negative electrode current collector 11 form an oxide layer 13.

  The negative electrode current collector 11 on which the oxide layer 13 is formed is taken up by the take-up roller 52 via the traveling roller 54. Thereafter, the oxygen flow rate control unit 65 is operated to adjust the flow rate of oxygen to a predetermined amount, and then the negative electrode current collector 11 on which the oxide layer 13 is formed is taken from the take-up roller 52 through the running roller 54 and the cooling roller 55. The negative electrode active material layer 12 is formed by forming a film of silicon oxide or silicon alone. The negative electrode current collector 11 in which the negative electrode active material layer 12 is formed on the oxide layer 13 is wound around the unwinding roller 51. The negative electrode plate 10 is formed by repeating the reciprocation of the unwinding roller 51 and the winding roller 52 a plurality of times while adjusting the flow rate of oxygen and depositing silicon oxide or silicon alone.

  Next, an example of a configuration of a nonaqueous electrolyte secondary battery obtained by applying the negative electrode plate 10 of the present embodiment will be described. FIG. 3 is a partially cutaway perspective view of a cylindrical lithium ion secondary battery 100 as an example of a nonaqueous electrolyte secondary battery using the negative electrode plate 10 of the present embodiment, cut vertically. In the cylindrical lithium ion secondary battery 100 of FIG. 3, a positive electrode plate 105 and a negative electrode plate 10 using a composite lithium oxide as an active material are wound in a spiral shape via a porous insulator 108, and an electrode group 109. Is produced.

  The electrode group 109 is housed inside the bottomed cylindrical battery case 101 while being insulated from the battery case 101 by the insulating plate 102, while the negative electrode lead 106 led out from the lower part of the electrode group 109 has the battery case 101. The positive electrode lead 107 led out from the upper part of the electrode group 109 is connected to the sealing plate 104 while being connected to the bottom. In addition, the battery case 101 is injected with a predetermined amount of an electrolyte solution (not shown) made of a non-aqueous solvent, and then a sealing plate 104 with a sealing gasket 103 attached to the periphery is inserted into the opening, and the battery case 101 is inserted. The opening is folded inward and crimped.

The positive electrode plate 105 includes, for example, a positive electrode current collector and a positive electrode active material layer provided on the positive electrode current collector, and is disposed so that the positive electrode active material layer side is in contact with the porous insulator 108. The positive electrode current collector is made of, for example, aluminum, nickel, stainless steel, or the like. The positive electrode active material layer includes, for example, any one or more of positive electrode materials capable of inserting and extracting lithium as a positive electrode active material, and a conductive material such as a carbon material and a polyfluoride as necessary. A binder such as vinylidene chloride may be included. As a positive electrode material capable of inserting and extracting lithium, for example, a lithium-containing metal composite oxide represented by a general formula Li _Z MO ₂ is preferable. This is because the lithium-containing metal composite oxide can generate a high voltage and has a high density, so that the capacity of the lithium ion secondary battery can be further increased.

Note that M in Li _Z MO ₂ is one or more transition metals, and for example, at least one of cobalt and nickel is preferable. Further, _Z of Li _Z MO ₂ varies depending on the charge / discharge state of the battery, and is usually a value in the range of 0.05 ≦ Z ≦ 1.10. Specific examples of such a lithium-containing metal composite oxide include LiCoO ₂ , LiNiO _2, LiMn ₂ O _{4 and the} like.

  For example, the positive electrode plate 105 is prepared by mixing a positive electrode active material, a conductive material, and a binder to prepare a mixture, and dispersing the mixture in a dispersion medium such as N-methylpyrrolidone to prepare a mixture slurry. The mixture slurry is applied to a positive electrode current collector made of a metal foil, dried, and then compression molded to form a positive electrode active material layer. The porous insulator 108 separates the negative electrode plate 10 and the positive electrode plate 105 and allows lithium ions to pass through while preventing a short circuit of current due to contact between both electrodes. The porous insulator 108 is made of, for example, polyethylene or polypropylene, and is impregnated with a nonaqueous electrolytic solution that is a liquid electrolyte.

This nonaqueous electrolytic solution contains, for example, a solvent and a lithium salt that is an electrolyte salt dissolved in the solvent, and may contain an additive as necessary. Examples of the solvent include organic solvents such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Any one or a combination of these may be used. Examples of the lithium salt include LiPF ₆ , LiCF ₃ SO _{3, and} LiClO ₄ , and one or more of these may be used in combination.

  Next, another embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a schematic cross-sectional view of the negative electrode plate of the present embodiment. The negative electrode plate 20 includes, for example, a negative electrode current collector 21 having unevenness with a large surface roughness Ra, a negative electrode active material layer 22 provided on the negative electrode current collector 21, a negative electrode current collector 21, and a negative electrode active material layer 22. And an oxide layer 23 provided therebetween. The oxide layer 23 covers the whole or part of the unevenness of the negative electrode current collector 21, and the negative electrode active material layer 22 is formed on the oxide layer 23. In particular, the negative electrode active material layer 22 is formed so as to largely cover the convex portion of the negative electrode current collector 21. “Surface roughness Ra” here refers to “arithmetic average roughness Ra” defined in Japanese Industrial Standards (JISB0601-1994), and can be measured using, for example, a surface roughness meter.

  The surface roughness Ra of the negative electrode current collector 21 is preferably 0.3 μm or more and 5.0 μm or less. When the surface roughness Ra is 0.3 μm or more, a sufficient gap can be formed between the adjacent negative electrode active material layers 22 more reliably, which is caused by the lateral expansion of the negative electrode active material layer 22 during charging. It is possible to secure a gap that suppresses contact. On the other hand, if the surface roughness Ra is too large, the negative electrode current collector 21 becomes thick and the capacity per unit volume of the negative electrode plate decreases, so the surface roughness Ra is preferably 5.0 μm or less. The negative electrode active material layer 22 and the oxide layer 23 may be formed on both surfaces of the negative electrode current collector 21, or may be formed only on one surface.

The negative electrode current collector 21 includes a highly conductive metal foil mainly composed of at least one metal element that does not form an intermetallic compound with lithium, a metal foil that has a higher tendency to form an oxide than the main component, It is constituted by adding at least one element having a high diffusion rate among the components. When an intermetallic compound is formed with lithium, it expands and contracts with charge / discharge, structural breakdown occurs, current collection performance decreases, and the ability to support the negative electrode active material layer 22 decreases, so that the negative electrode active material layer 22 becomes a negative electrode. This is because it is easy to drop off from the current collector 21. As an example of the additive element, for example, when the main component of the metal foil of the negative electrode current collector 21 is copper, Mn, Nb, Zr, Cr, V, Tc
, Rc are desirable, and Mn is particularly desirable.

  The oxide layer 23 is formed by forming the negative electrode active material layer 22 in an oxidizing atmosphere. That is, when the negative electrode active material is formed in an oxidizing atmosphere, first, an additive element having a strong oxide formation tendency in the negative electrode current collector 21 is preferentially diffused on the surface of the negative electrode current collector 21. The additive element diffused on the surface of the negative electrode current collector 21 and the oxide of the negative electrode active material form the oxide layer 23. In order to promote the formation of the oxide layer 23, heat treatment may be performed in an oxidizing atmosphere.

The negative electrode active material layer 22 includes, for example, at least one selected from the group consisting of a single element, an alloy, and a compound of an element capable of forming an alloy with lithium as a negative electrode active material. Among these, as the negative electrode active material, a simple substance of silicon, an oxide represented by a general formula SiO _x (0 <x ≦ 2) or a simple substance of tin, an oxidation represented by a general formula SnO _y (0 <y ≦ 2). It is preferable to include at least one member selected from the group consisting of products. Furthermore, when the average value of the oxygen amount when viewed from the whole negative electrode active material layer 22 is O _av22 and the average value of the oxygen amount when viewed from the whole oxide layer 23 is O _M23 , the relationship of O _M23 > O _av22 is obtained. be satisfied. By _making the relationship O _M23 > O _av22 , it is possible to suppress the expansion of the oxide layer 23 due to occlusion of lithium during charging, and to suppress the separation of the oxide layer 23 and the negative electrode active material layer 22. it can.

The negative electrode active material layer 22 is preferably formed by at least one method selected from the group consisting of a vapor deposition method, a sputtering method, and a sintering method, for example. In order to satisfy the relationship of O _M23 > O _av22 , for example, in the vapor deposition method, O _M23 > O _av22 can be _achieved by changing the oxygen concentration of the atmospheric gas. That is, the oxygen concentration in the atmospheric gas is decreased with time, or the oxygen concentration C3 is set from the start of the formation of the negative electrode active material layer 22 to a predetermined time, and thereafter, the concentration C4 is lower than C3. Can be formed.

  For this negative electrode plate 20, a negative electrode current collector 21 made of, for example, a metal foil is prepared, and silicon and oxygen are supplied to the surface of the negative electrode current collector 21 using a vapor deposition apparatus as shown in FIG. It can be carried out by depositing silicon oxide having a composition or silicon simple substance. The vapor deposition apparatus 80 shown in FIG. 5 includes a vacuum chamber 76 and a vacuum exhaust pump 77 for exhausting the vacuum chamber 76. Inside the vacuum chamber 76, the unwinding roller 51 and the winding roller 52 that hold the negative electrode current collector 21, the traveling rollers 53 and 54, the cooling rollers 56, 57, and 58, and an oxygen gas are emitted. Oxygen nozzles 66 and 68, a silicon raw material 73 that is an evaporation source for supplying silicon, an evaporation crucible 74 that holds the silicon raw material 73, and an electron irradiation unit 75 for evaporating the silicon raw material 73 are provided. .

  The oxygen nozzles 66 and 68 are connected to oxygen flow rate control units 67 and 69 and an oxygen cylinder (not shown) via a pipe. Also, shielding plates 60, 61 and 62 are provided inside the vacuum chamber 76, and oxygen emitted from the oxygen nozzles 66 and 68 and silicon evaporated from the silicon raw material 73 are contained in the shielding plates 60 and 61. It is supplied to the surface of the negative electrode current collector 21 from the direction inclined with respect to the normal direction of the negative electrode current collector 21 through the gap and the gap between the shielding plate 61 and the shielding plate 62.

  A region defined by a gap between the shielding plate 60 and the shielding plate 61 and supplied with silicon oxide or silicon alone and oxygen on the surface of the negative electrode current collector 21 is defined as a negative electrode active material formation region 71, a shielding plate 61 and a shielding plate 62. A region defined by the gap and where silicon oxide or silicon alone and oxygen are supplied to the surface of the negative electrode current collector 21 is referred to as a negative electrode active material forming region 72.

A method of forming the negative electrode plate 20 using such a vapor deposition apparatus 80 will be described below. The negative electrode current collector 21 made of metal foil is installed on the unwinding roller 51, and the vacuum chamber 76 is evacuated by the vacuum evacuation pump 77. When the vacuum degree of the vacuum chamber 76 reaches a predetermined vacuum level, the negative electrode current collector 21 is moved along the cooling rollers 56, 57 and 58 from the unwinding roller 51 through the running roller 53 while exhausting the vacuum chamber 76. And run. Meanwhile, the silicon raw material 73 contained in the evaporation crucible 74 is irradiated with electrons from the electron irradiation unit 75 to melt and evaporate silicon. The evaporation amount of silicon is controlled by using a film thickness controller (not shown) connected to the film thickness monitor 63. At the same time, a predetermined amount of oxygen is introduced into the vacuum chamber 76 from the oxygen nozzles 66 and 68. The flow rate of oxygen is controlled by oxygen flow rate control units 67 and 69. Silicon and oxygen pass through the gap between the shielding plate 60 and the shielding plate 61 and the gap between the shielding plate 61 and the shielding plate 62, and in the negative electrode active material formation region 71 and the negative electrode active material formation region 72, the cooling rollers 56, 57 and 58 is supplied to the surface of the negative electrode current collector 21 that travels 58.

  In the negative electrode active material layer forming region 71, silicon oxide or silicon simple substance enters from a direction having an angle (0 ° to 90 °) with respect to the normal direction of the traveling negative electrode current collector 21, and the negative electrode active material layer is formed. In the material layer forming region 72, silicon oxide or silicon simple substance enters from a direction having an angle (−90 ° to 0 °) with respect to the normal direction of the traveling negative electrode current collector 21. Silicon is incident and deposited from a direction symmetrical to the negative electrode active material layer forming region 71. At this time, since silicon oxide or silicon simple substance is incident on the surface of the negative electrode current collector 21 at an angle inclined from the normal direction of the negative electrode current collector 21, it is deposited on the convex portion 24 on the surface of the negative electrode current collector 21. It becomes easy.

  On the other hand, in the concave portion on the surface of the negative electrode current collector 21, it becomes a shadow of silicon oxide or silicon simple substance deposited on the convex portion 24, so that the silicon oxide or silicon simple substance becomes difficult to be incident. The amount of deposition decreases compared to the convex portion 24. When silicon oxide is deposited on the negative electrode current collector 21, silicon oxide, oxygen, and additive elements diffused on the surface of the negative electrode current collector 21 form an oxide layer 23. The negative electrode current collector 21 on which the oxide layer 23 is formed is taken up by a take-up roller 52 via a traveling roller 54. Thereafter, the oxygen flow rate control units 67 and 69 are operated to adjust the oxygen flow rate to a predetermined amount, and then the negative electrode current collector 21 on which the oxide layer 23 is formed is cooled from the take-up roller 52 via the traveling roller 54. The negative electrode active material layer 22 is formed by forming a film of silicon oxide or silicon alone by running along the rollers 58, 57 and 56. The negative electrode current collector 21 in which the negative electrode active material layer 22 is formed on the oxide layer 23 is wound around the unwinding roller 51. The negative electrode plate 20 is formed by repeating the reciprocation of the unwinding roller 51 and the winding roller 52 a plurality of times while adjusting the flow rate of oxygen and depositing silicon oxide or simple silicon.

  An example of the configuration of the non-aqueous electrolyte secondary battery obtained by applying the negative electrode plate 20 of another embodiment of the present invention is the cylindrical lithium ion secondary shown in one embodiment of the present invention. Since the negative electrode plate 10 used for the battery 100 is not changed to the negative electrode plate 20 of the present embodiment, the configuration is not changed and the description thereof is omitted.

Using the vapor deposition apparatus 50 shown in FIG. 2, silicon oxide or silicon simple substance was deposited on the surface of the negative electrode current collector 11 to form the oxide layer 13 and the negative electrode active material layer 12. As the negative electrode current collector 11, a negative electrode current collector 11 made of a copper foil having a thickness of 30 μm and containing 10 atomic% of Mn was used. After the negative electrode current collector 11 was placed on the unwinding roller 51 and before the vapor deposition, the vacuum pump 76 was evacuated using the exhaust pump 77 until the inside of the vacuum chamber 76 reached 3 × 10 ⁻⁴ Pa. After that, the evaporation crucible 74 containing 200 g of the silicon raw material 73 was irradiated with electrons accelerated at −10 kV from the electron irradiation unit 75 to melt and evaporate the silicon raw material. The evaporation amount of silicon was 0.04 g / sec.

On the other hand, oxygen was introduced into the vacuum chamber 76 from the oxygen nozzle 64. At this time, the negative electrode current collector 11 in which the tip of the oxygen nozzle 64 is located at a height of 200 mm from the evaporation crucible 74 and the emission direction of oxygen travels along the cooling roller 55 through the gap of the shielding plate 59. An oxygen nozzle 64 was disposed so as to face the surface. The oxygen flow rate control unit 65 was used to control the oxygen flow rate from the oxygen nozzle 64 to 1200 sccm.

  Thereafter, in the vacuum chamber 76, the negative electrode current collector 11 is caused to travel along the cooling roller 55 from the unwinding roller 51 through the travel roller 53 at a speed of 1 m / min (substrate travel speed). Then, the oxide layer 13 was formed and wound around the winding roller 52. Thereafter, the oxygen flow rate from the oxygen nozzle 64 is controlled to 1080 sccm, and then the oxide layer 13 is formed at a speed of 1 m / min (substrate travel speed) from the take-up roller 52 through the travel roller 54 and the cooling roller 55. The negative electrode current collector 11 thus produced was run to form the negative electrode active material layer 12 on the oxide layer 13. Thereafter, film formation of silicon oxide or silicon alone was performed under the condition of an oxygen flow rate of 960 sccm, and the negative electrode plate 10 was obtained.

  In Example 1, silicon oxide or silicon simple substance enters the traveling negative electrode current collector 11 from a direction having an angle of −13 ° with respect to the normal direction of the negative electrode current collector 11. As described above, the positions of the evaporation crucible 74 and the shielding plate 59 were set. The distance between the evaporation crucible 74 and the negative electrode current collector 11 was 400 mm. In this way, while reciprocating between the unwinding roller 51 and the winding roller 52, silicon and oxygen are supplied to the surface of the negative electrode current collector 11 to deposit silicon oxide or silicon alone, and the oxide layer 13 and A negative electrode active material layer 12 was formed. The obtained oxide layer 13 was 0.1 μm thick, and the negative electrode active material layer 12 was 14 μm thick.

Next, the positive electrode plate 105 is composed of lithium cobalt oxide (LiCoO ₂ ) powder having an average particle diameter of 5 μm as a positive electrode active material, carbon black as a conductive material, and polyvinylidene fluoride as a binder. Black: polyvinylidene fluoride = 92: 3: 5 is mixed at a mass ratio, and this is added to N-methylpyrrolidone as a dispersion medium to form a mixture slurry, which is applied to a positive electrode current collector made of aluminum having a thickness of 15 μm. It was prepared by drying and pressurizing to form a positive electrode active material layer.

The negative electrode plate 10 and the positive electrode plate 105 were wound in a spiral shape so as to face each other through a polyethylene porous insulator 108, and an electrode group 109 was configured and inserted into the battery case 101. Next, a non-aqueous electrolyte obtained by dissolving 1M LiPF ₆ as a solute in a solvent mixed with ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1 was poured into the case 101. After that, a cylindrical lithium ion secondary battery manufactured by inserting a sealing plate 104 with a sealing gasket 103 attached to the periphery thereof into the opening of the case 101, bending the opening of the battery case 101 inward, and sealing it by caulking. Was taken as Example 1.

Using the vapor deposition apparatus 80 shown in FIG. 5, silicon oxide was deposited on the surface of the negative electrode current collector 21 to form the oxide layer 23 and the negative electrode active material layer 22. As the negative electrode current collector 21, a negative electrode current collector 21 made of a copper foil having a surface roughness Ra of 2.0 μm and a thickness of 40 μm containing 10 atomic% of Mn was used. After the negative electrode current collector 21 was installed on the unwinding roller 51 and before vapor deposition, the exhaust pump 77 was used to evacuate the inside of the vacuum chamber 76 until it reached 3 × 10 ⁻⁴ Pa. After that, the evaporation crucible 74 containing 200 g of the silicon raw material 73 was irradiated with electrons accelerated at −10 kV from the electron irradiation unit 75 to melt and evaporate the silicon raw material. The evaporation amount of silicon was 0.06 g / sec.

On the other hand, oxygen was introduced into the vacuum chamber 76 from the oxygen nozzles 66 and 68. At this time, the tip of the oxygen nozzle 66 is located at a height of 220 mm from the evaporation crucible 74, and the oxygen emission direction is along the cooling roller 56 and the cooling roller 57 via the gap between the shielding plate 60 and the shielding plate 61. The tip of the oxygen nozzle 68 is located at a height of 220 mm from the evaporation crucible 74, and the direction of oxygen emission is shielded from the shielding plate 61. The cooling roller 57 and the negative electrode current collector 11 traveling along the cooling roller 58 are arranged in parallel to each other through a gap between the plates 62. Further, the oxygen flow rate from the oxygen nozzle 66 was controlled to 900 sccm using the oxygen flow rate control unit 67, and the oxygen flow rate from the oxygen nozzle 68 was controlled to 900 sccm using the oxygen flow rate control unit 69.

  Thereafter, the negative electrode current collector 21 is caused to travel at a speed of 1.5 m / min (substrate traveling speed) along the cooling rollers 56, 57 and 58 from the unwinding roller 51 through the traveling roller 53 in the vacuum chamber 76. The oxide layer 23 was formed on the negative electrode current collector 21, and wound around the winding roller 52. Thereafter, the oxygen flow rates of the oxygen nozzles 66 and 68 are controlled to 810 sccm, respectively, and then a speed of 1.5 m / min (substrate travel speed) from the take-up roller 52 through the travel roller 54 along the cooling rollers 58, 57 and 56. The negative electrode current collector 21 having the oxide layer 23 formed thereon was run to form the negative electrode active material layer 22 on the oxide layer 23. Thereafter, the negative electrode plate 20 was obtained by depositing silicon oxide or silicon alone under the condition of an oxygen flow rate of 720 sccm.

  In the second embodiment, the silicon oxide is oxidized from a direction having an angle (65 °) with respect to the normal direction of the negative electrode current collector 21 in the negative electrode active material formation region 71 with respect to the traveling negative electrode current collector 21. In the negative electrode active material formation region 72, silicon oxide or silicon simple substance is incident from a direction having an angle (−72 °) with respect to the normal direction of the negative electrode current collector 21 so that an object or silicon simple substance enters. The positions of the evaporation crucible 74 and the shielding plates 60, 61 and 62 were set. The distance between the evaporation crucible 74 and the center of the negative electrode current collector 21 running on the cooling rollers 56 and 57 and the distance between the evaporation crucible 74 and the center of the negative electrode current collector 21 running on the cooling rollers 57 and 58 are 450 mm, respectively. did.

  In this way, while reciprocating between the unwinding roller 51 and the winding roller 52, silicon and oxygen are supplied to the surface of the negative electrode current collector 21 to deposit silicon oxide or silicon alone, and the oxide layer 23 and A negative electrode active material layer 22 was formed. The obtained oxide layer 23 was 0.2 μm thick, and the negative electrode active material layer 22 was 15 μm thick.

  Next, the negative electrode plate 10 and the same positive electrode plate 105 as the positive electrode plate used in Example 1 were wound through a porous insulator 108 to constitute an electrode group 109 and inserted into the battery case 101. Next, the same nonaqueous electrolyte as in Example 1 was poured into the case 101, and a sealing plate 104 with a sealing gasket 103 attached to the periphery was inserted into the opening of the case 101 so that the opening of the battery case 101 was inward. A cylindrical lithium ion secondary battery produced by bending and caulking and sealing was designated as Example 2.

(Comparative Example 1)
Formation of the negative electrode active material layer 32 on the negative electrode current collector 31 under the same conditions as in Example 1 except that the negative electrode current collector 41 made of a copper foil containing no Mn is used using the vapor deposition apparatus 50 shown in FIG. The negative electrode plate 30 having no oxide layer shown in FIG. 6 was produced. Next, a cylindrical lithium ion secondary battery produced in the same manner as in Example 1 was used as Comparative Example 1.

(Comparative Example 2)
The same conditions as in Example 2 except that a negative electrode current collector 41 made of a copper foil having a surface roughness Ra not containing Mn of 2.0 μm and a thickness of 40 μm is used, using the vapor deposition apparatus 80 shown in FIG. Then, the negative electrode active material layer 42 was formed on the negative electrode current collector 41, and the negative electrode plate 40 having no oxide layer shown in FIG. 7 was produced. Next, a cylindrical lithium ion secondary battery produced in the same manner as in Example 1 was referred to as Comparative Example 2.

  An analysis / evaluation method and results of the negative electrode plates of Examples and Comparative Examples obtained by the above-described method will be described. Here, the chemical compositions and thicknesses of the oxide layer 13, the oxide layer 23, the negative electrode active material layer 12, and the negative electrode active material layer 22 in the negative electrode plates of Examples and Comparative Examples were measured. Furthermore, batteries using these negative electrode plates were prepared, and the cycle characteristics were measured and evaluated.

  As the measurement of the chemical composition, the negative electrode active material layer 12, the oxide layer 13, the negative electrode active material layer 22 and the oxidation of Example 1 and Example 2 in which the negative electrode plate before constituting the cylindrical lithium ion secondary battery was sampled was sampled. The chemical composition of the physical layer 23 was measured by the following method. First, the negative electrode plate 10 in which the oxide layer 13 and the negative electrode active material layer 12 are formed on the negative electrode current collector 11 and the negative electrode plate in which the oxide layer 23 and the negative electrode active material layer 22 are formed on the negative electrode current collector 21 Samples for measurement each having a width of 1 cm and a length of 1 cm were cut from 20.

Thereafter, using an X-ray photoelectron spectroscopy (XPS) method, Ar etching is performed from the surface of the negative electrode active material layer 12 and the negative electrode active material layer 22 to analyze the depth direction and measure the Si _2p binding energy of the exposed surface. Then, the identification of the elements contained in the negative electrode active material layer 12, the oxide layer 13, the negative electrode active material layer 22 and the oxide layer 23 and the average value of the oxygen composition ratio were calculated. Furthermore, the chemical composition of the negative electrode active material layer was measured for the negative electrode plates of Comparative Example 1 and Comparative Example 2 in the same manner as described above.

As a result of the above analysis, the composition of the negative electrode active material layer 12 of Example 1 is SiO _1.2 , the composition of the oxide layer 13 is MnSiO _1.5 , and the composition of the negative electrode active material layer 22 of Example 2 is SiO _{1. 3} and the composition of the oxide layer 23 was MnSiO _1.6 . The composition of the negative electrode active material layer 32 of Comparative Example 1 was SiO _1.2 , and the composition of the negative electrode active material layer 42 of Comparative Example 2 was SiO _1.3 . In addition, the thickness of the active material layer and the oxide layer was measured from the depth direction analysis results obtained by measuring the above chemical composition, and the area where silicon and oxygen were detected was defined as the thickness of the negative electrode active material layer. The region where oxygen and Mn were detected was defined as the thickness of the oxide layer.

In addition, as an evaluation of the cycle characteristics of the cylindrical lithium ion secondary battery, the produced cylindrical lithium ion secondary battery is subjected to a charge / discharge test under a condition of 25 ° C., and the capacity retention rate at the 100th cycle is obtained. It was. The capacity retention rate was measured by charging each lithium ion secondary battery at a constant current density of 1 mA / cm ² until the battery voltage reached 4.2 V, and then at a constant current density of 1 mA / cm ^2. Discharging was performed until the voltage of the battery reached 2.5V. The capacity maintenance ratio at the 100th cycle was calculated as the ratio of the discharge capacity at the 100th cycle to the initial discharge capacity, that is, (discharge capacity at the 100th cycle / initial discharge capacity)%. The obtained results are shown in (Table 1).

  As can be seen from (Table 1), the capacity retention rate after 100 cycles of the lithium ion secondary battery using the negative electrode plate of Example 1 and Example 2 in which the oxide layer 13 and the oxide layer 23 were formed was The lithium ion secondary battery using the negative electrode plate of Example 1 shows 92%, and the lithium ion secondary battery using the negative electrode plate of Example 2 shows 97%, and has excellent charge / discharge cycle characteristics. all right.

  On the other hand, the capacity retention after 100 cycles of the lithium ion secondary batteries using the negative electrode plates of Comparative Example 1 and Comparative Example 2 in which the oxide layer was not formed was the same as that of the lithium ion secondary battery using the negative electrode plate of Comparative Example 1. The secondary battery showed 75%, and the lithium ion secondary battery using the negative electrode plate of Comparative Example 2 showed 82%, and the capacity retention rate was lower than that of Example 1 and Example 2. This is considered to be because the negative electrode active material was peeled off from the negative electrode current collector due to the expansion and contraction of the negative electrode active material accompanying charge / discharge.

  Therefore, it was confirmed that the charge / discharge cycle characteristics can be improved by forming an alloy layer in which the elements contained in the metal foil of the negative electrode current collector are diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material. It was. Although Mn is taken as an example of the additive element of Example 1 and Example 2, when the main component of the metal foil of the negative electrode current collector is copper, at least one of Mn, Nb, Zr, Cr, V, Tc, and Rc is used. By using the type, it is possible to form an alloy layer in which the elements contained in the metal foil of the negative electrode current collector are diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material layer, and charge / discharge Cycle characteristics can be improved.

  While the present invention has been described with reference to the embodiment and examples, the present invention is not limited to the above embodiment and example, and various modifications are possible. For example, in the above embodiments and examples, the negative electrode current collector 11 or the negative electrode current collector 21 is provided with the negative electrode active material layer 12 or the negative electrode active material layer 22 with the oxide layer 13 or the oxide layer 23 interposed therebetween. Although the negative electrode plate 10 or the negative electrode plate 20 was demonstrated, you may have another layer further. For example, another layer may be provided between the oxide layer 13 or the oxide layer 23 and the negative electrode active material layer 12 or the negative electrode active material layer 22. You may have another layer on top.

  Moreover, although the lithium ion secondary battery was demonstrated in the said embodiment and Example, it is not limited to the cylindrical lithium ion secondary battery of the structure shown in FIG. The negative electrode plate of the present invention can be applied to non-aqueous electrolyte secondary batteries of various shapes such as a coin shape, a square shape, a button shape, a thin shape, a large size, and a laminated laminate type in addition to a cylindrical lithium ion secondary battery. is there. Further, the sealing form of the nonaqueous electrolyte secondary battery and the material of each element constituting the battery are not particularly limited. Moreover, not only a secondary battery but a primary battery is applicable.

  The negative electrode plate for a non-aqueous electrolyte secondary battery of the present invention is a non-aqueous electrolyte having various shapes such as a coin-shaped, square, button-shaped, thin, large-sized, laminated laminate type, etc. in addition to a cylindrical lithium ion secondary battery. Applicable to secondary battery. Since these non-aqueous electrolyte secondary batteries have excellent cycle characteristics, they are useful for portable information terminals such as PCs, mobile phones, and PDAs, and audiovisual equipment such as video recorders and memory audio players.

DESCRIPTION OF SYMBOLS 10,20 Negative electrode plate 11,21 Negative electrode collector 12,22 Negative electrode active material layer 13,23 Oxide layer 24 Convex part 50,80 Vacuum vapor deposition part 51 Unwinding roller 52 Winding roller 53,54 Traveling roller 55,56 , 57, 58 Cooling roller 59, 60, 61, 62 Shield plate 63 Film thickness monitor 64, 66, 68 Oxygen nozzle 65, 67, 69 Oxygen flow control unit 70, 71, 72 Active material layer formation region 73 Silicon raw material (evaporation) source)
74 Evaporating crucible 75 Electron irradiation unit 76 Vacuum tank 77 Vacuum exhaust pump 100 Lithium ion secondary battery 101 Battery case 102 Insulating plate 103 Sealing gasket 104 Sealing plate 105 Positive electrode plate 106 Negative electrode lead 107 Positive electrode lead 108 Porous insulator 109 Electrode group

Claims (7)

  A negative electrode plate for a non-aqueous secondary battery in which a negative electrode current collector made of metal foil is loaded with a negative electrode active material made of silicon or tin alone or a compound containing silicon or tin and oxygen, the negative electrode current collector A negative electrode plate for a nonaqueous electrolyte secondary battery, wherein an oxide layer in which an element contained in a metal foil of a negative electrode current collector is diffused into a negative electrode active material is formed at an interface between the body and the negative electrode active material layer.   2. The non-aqueous electrolyte 2 according to claim 1, wherein the element contained in the metal foil of the negative electrode current collector is an element having a stronger tendency to form an oxide than the main component of the metal foil and having a high diffusion rate in the metal foil. Negative electrode for secondary battery.   3. The non-electrode according to claim 2, wherein a main component of the metal foil of the negative electrode current collector is copper, and an element contained in the metal foil is at least one of Mn, Nb, Zr, Cr, V, Tc, and Rc. Negative electrode plate for water electrolyte secondary battery.   The negative electrode plate for a nonaqueous electrolyte secondary battery according to claim 1, wherein a number of irregularities are formed on the surface of a metal foil carrying a negative electrode active material as the negative electrode current collector.   Forming a negative electrode current collector made of a metal foil containing an element having a strong oxide formation tendency and a high diffusion rate in the metal foil with a negative electrode active material made of a compound of silicon or tin and oxygen in an oxygen atmosphere And forming an oxide layer in which the element contained in the metal foil of the negative electrode current collector is diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material by a thermal reaction during the film formation. A method for producing a negative electrode plate for a non-aqueous electrolyte secondary battery.   Forming a negative electrode current collector made of a metal foil containing an element having a strong oxide formation tendency and a fast diffusion coefficient in the metal foil with a negative electrode active material made of a compound of silicon or tin and oxygen in an oxygen atmosphere And performing heat treatment to form an oxide layer in which an element contained in the metal foil of the negative electrode current collector is diffused into the negative electrode active material at the interface between the negative electrode current collector and the negative electrode active material. The manufacturing method of the negative electrode plate for nonaqueous electrolyte secondary batteries.   An electrode group formed by winding or laminating a positive electrode plate having a positive electrode active material formed on the surface of the positive electrode current collector and a negative electrode plate having a negative electrode current material formed on the surface of the negative electrode current collector via a porous insulating layer A non-aqueous electrolyte secondary battery in which a non-aqueous electrolyte is enclosed in a battery case, wherein the negative electrode plate for a non-aqueous electrolyte secondary battery according to any one of claims 1 to 4 is used as the negative electrode plate. Non-aqueous electrolyte secondary battery.

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