Lead conductor and nonaqueous electrolyte battery

Abstract

A lead conductor according to the present invention is provided with: a conductor extending in a first direction; and an insulating film covering the outer peripheral surface of the conductor between a first end section of the conductor and a second end section of the conductor, the second end section being opposite to the first end section as viewed along the first direction, while exposing the first end section and the second end section. The conductor includes: a substrate made of copper or a copper alloy; and a surface treatment layer provided on the substrate. The insulating film is provided directly over the surface treatment layer. A first surface of the surface treatment layer in contact with the insulating film includes a region having an arithmetic average roughness Ra1 as defined in JIS B 0601:2001 of 0.05-0.3 μm along the first direction, and an arithmetic average roughness Ra2 as defined in JIS B 0601:2001 of 0.15-0.8 μm along a second direction perpendicular to the first direction, and in which Ra2 is greater than Ra1 by at least 0.1 μm.

Description

Lead conductor and non-aqueous electrolyte battery

[0001] The present disclosure relates to a lead conductor and a nonaqueous electrolyte battery. This application claims priority to Japanese Patent Application No. 2024-107280, filed on July 3, 2024. The entire contents of this Japanese patent application are incorporated herein by reference.

[0002] Patent Document 1 discloses a nonaqueous electrolyte battery in which a lead conductor and an enclosed container are bonded via a sealant. In Patent Document 1, in order to improve the adhesive strength between the lead conductor and the sealant, the surface roughness parameter Spk of the lead conductor surface that comes into contact with the sealant is adjusted to 0.26 μm or more.

[0003] Japanese Patent Application Laid-Open No. 2023-168721

[0004] The lead conductor of the present disclosure includes a conductor extending in a first direction, and an insulating film covering an outer peripheral surface of the conductor between the first end and the second end of the conductor while exposing a first end of the conductor in the first direction and a second end of the conductor opposite to the first end when viewed along the first direction, wherein the conductor has a base made of copper or a copper alloy and a surface treatment layer provided on the base, the insulating film is provided directly on the surface treatment layer, and a first surface of the surface treatment layer in contact with the insulating film has an arithmetic mean roughness Ra1 defined in JIS B 0601:2001 in the first direction of 0.05 μm or more and 0.3 μm or less, and a surface roughness Ra2 defined in JIS B 0601:2001 in a second direction perpendicular to the first direction of the lead conductor. The lead conductor has an arithmetic mean roughness Ra2 defined in JIS K 0601:2001 of 0.15 μm or more and 0.8 μm or less, and includes a region where the Ra2 is 0.1 μm or more larger than the Ra1.

[0005] Fig. 1 is a schematic overview of an example of a lead conductor according to embodiment 1. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is a front view schematically showing an example of a nonaqueous electrolyte battery according to embodiment 2. Fig. 5 is a partial cross-sectional view taken along line V-V in Fig. 4.

[0006] [Problem to be Solved by the Present Disclosure] Non-aqueous electrolyte batteries generate heat during use, causing the pressure inside the sealed container to rise. If the pressure inside the sealed container rises excessively, it becomes necessary to release the pressure to the outside. In particular, since the adhesive force between the lead conductor and the sealed container is strong in the early stages of use of a non-aqueous electrolyte battery, there is a need for a lead conductor that can release the pressure inside the sealed container to the outside if the pressure inside the sealed container rises excessively, even in the early stages of use.

[0007] One possible method for releasing the pressure inside the sealed container to the outside is to peel off the adhesive between the lead conductor and the sealed container in a direction from the inside to the outside of the sealed container when the pressure inside the sealed container rises excessively, and release the pressure from the peeled off part.

[0008] The lead conductor includes a conductor and an insulating film covering the conductor. At the adhesive portion between the lead conductor and the sealed container, the conductor and the sealed container are adhered via the insulating film. The sealed container and the insulating film are difficult to separate. Therefore, peeling of the adhesive portion between the lead conductor and the sealed container is achieved by peeling the conductor and the insulating film.

[0009] An object of the present disclosure is to provide a lead conductor that, when used in a nonaqueous electrolyte battery, can appropriately control the adhesive force between the conductor and the insulating film along the direction from the inside to the outside of the sealed container, even in the early stages of use, and a nonaqueous electrolyte battery including the lead conductor.

[0010] [Effects of the Present Disclosure] According to the present disclosure, it is possible to provide a lead conductor that, particularly when used in a nonaqueous electrolyte battery, can appropriately control the adhesive force between the conductor and the insulating film along the direction from the inside to the outside of the sealed container, even in the early stages of use, and a nonaqueous electrolyte battery including the lead conductor.

[0011] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be described below. (1) A lead conductor of the present disclosure includes a conductor extending in a first direction, and an insulating film covering an outer peripheral surface of the conductor between a first end of the conductor in the first direction and a second end of the conductor opposite to the first end when viewed along the first direction, while exposing the first end and the second end of the conductor, wherein the conductor has a base made of copper or a copper alloy and a surface treatment layer provided on the base, the insulating film is provided directly on the surface treatment layer, and a first surface of the surface treatment layer in contact with the insulating film has an arithmetic mean roughness Ra1 in the first direction as defined in JIS B 0601:2001 of 0.05 μm or more and 0.3 μm or less, and a surface roughness Ra2 in a second direction perpendicular to the first direction as defined in JIS B 0601:2001 of 0.05 μm or more and 0.3 μm or less. The lead conductor has an arithmetic mean roughness Ra2 defined in JIS K 0601:2001 of 0.15 μm or more and 0.8 μm or less, and includes a region where the Ra2 is 0.1 μm or more larger than the Ra1.

[0012] According to the present disclosure, it is possible to provide a lead conductor that, when used in a nonaqueous electrolyte battery in particular, can appropriately control the adhesive force between the conductor and the insulating film along the direction from the inside to the outside of the sealed container, even in the early stages of use, and a nonaqueous electrolyte battery including the lead conductor.

[0013] (2) In the above (1), the first surface may include a region in which the skewness Rsk2 defined in JIS B 0601:2001 in the second direction is greater than 0. This improves the overall adhesive strength between the conductor and the insulating film while maintaining the ease of peeling between the conductor and the insulating film in the first direction.

[0014] (3) In the above (1) or (2), the surface treatment layer may include a nickel-containing metal layer provided on the substrate and a chromium-containing non-metal layer provided on the metal layer. By providing the nickel-containing metal layer, oxidation degradation of the insulating film can be suppressed. Furthermore, by providing the chromium-containing non-metal layer, hydrogen bonding between the insulating film and the conductor inside the non-aqueous electrolyte battery can be strengthened, thereby maintaining long-term adhesion between the conductor and the insulating film. The surface treatment layer may include a nickel-containing metal layer provided on the substrate and a chromium-containing non-metal layer provided on the metal layer.

[0015] (4) In the above (3), the average thickness of the metal layer may be 0.5 μm or more and 5.0 μm or less, which makes it possible to suppress oxidation degradation of the insulating film while maintaining productivity and processability.

[0016] (5) In the above (3) or (4), the metal layer may include a nickel-phosphorus alloy layer having a phosphorus content of 6% by mass or more and 16% by mass or less, and the non-metallic layer may be provided directly on the nickel-phosphorus alloy layer. This can suppress corrosion and dissolution of the metal layer inside the non-aqueous electrolyte battery, and can maintain adhesion between the conductor and the insulating film for a long period of time.

[0017] (6) In the above (5), the average thickness of the nickel phosphorus alloy layer may be 0.2 μm or more and 5.0 μm or less, thereby improving the corrosion resistance of the nickel phosphorus alloy layer.

[0018] (7) In any one of the above (3) to (6), the chromium content of the nonmetallic layer is 1 mg / m ２ 20mg / m or more ２ This improves the corrosion resistance of the nickel plating.

[0019] (8) In any one of the above (1) to (7), the insulating film may include a first insulating layer provided in contact with the conductor and a second insulating layer provided on the surface of the first insulating layer opposite to the surface in contact with the conductor, the first insulating layer being an acid-modified polypropylene layer, and the second insulating layer being a heat-resistant resin layer, thereby providing the insulating film with good adhesion and sealing properties to the conductor.

[0020] (9) A nonaqueous electrolyte battery according to the present disclosure includes an enclosed container and the lead conductor according to any one of (1) to (8) above, which is arranged so as to extend from the inside to the outside of the enclosed container, and the insulating film is fused to the enclosed container.

[0021] According to the present disclosure, it is possible to provide a nonaqueous electrolyte battery having a lead conductor that can appropriately control the adhesive force between the conductor and the insulating film along the direction from the inside to the outside of the sealed container, even in the early stages of use.

[0022] [Details of the embodiments of the present disclosure] Specific examples of the lead conductor and nonaqueous electrolyte battery of the present disclosure will be described below with reference to the drawings. In the drawings of the present disclosure, the same reference numerals represent the same or corresponding parts. Furthermore, dimensional relationships such as length, width, thickness, and depth have been changed as appropriate for clarity and simplification of the drawings, and do not necessarily represent actual dimensional relationships.

[0023] In this specification, the notation in the form of "A to B" means A or more and B or less, and when no unit is specified for A and a unit is specified only for B, the unit of A and the unit of B are the same.

[0024] In the present specification, when a compound or the like is represented by a chemical formula, unless the atomic ratio is particularly limited, it is understood to include any conventionally known atomic ratio, and is not necessarily limited to only those within the stoichiometric range.

[0025] In the present disclosure, when one or more numerical values ​​are listed as the lower limit and the upper limit of a numerical range, the combination of any one numerical value listed as the lower limit and any one numerical value listed as the upper limit is also considered to be disclosed.

[0026] In this disclosure, "comprises," "includes," "has," and variations thereof are open-ended terms. Open-ended terms may or may not include additional elements in addition to the required elements. The term "consisting of" is closed-ended. However, even a configuration expressed in closed terms may include additional elements that are normally incidental impurities or unrelated to the subject technology.

[0027] [Embodiment 1: Lead Conductor] A lead conductor according to one embodiment of the present disclosure (hereinafter also referred to as "Embodiment 1") will be described with reference to Figures 1 to 3. Furthermore, the arrangement of the lead conductor when the lead conductor of Embodiment 1 is applied to a nonaqueous electrolyte battery will be described with reference to Figures 4 and 5.

[0028] 1 , the lead conductor 10 of the first embodiment includes a conductor 3 extending in a first direction, a first end 3a of the conductor 3 in the first direction, and an insulating film 1 covering the outer surface of the conductor 3 between the first end 3a and the second end 3b of the conductor 3 while exposing a second end 3b opposite the first end 3a of the conductor 3 when viewed along the first direction. The conductor 3 has a base 4 made of copper or a copper alloy and a surface treatment layer 7 provided on the base 4. The insulating film 1 is provided directly on the surface treatment layer 7. The first surface 7a of the surface treatment layer 7 in contact with the insulating film 1 has an arithmetic mean roughness Ra1 in a first direction as defined in JIS B 0601:2001 of 0.05 μm or more and 0.3 μm or less, an arithmetic mean roughness Ra2 in a second direction perpendicular to the first direction as defined in JIS B 0601:2001 of 0.15 μm or more and 0.8 μm or less, and includes a region where Ra2 is 0.1 μm or more greater than Ra1.

[0029] As shown in FIG. 2, the surface treatment layer 7 is provided at least between the substrate 4 and the insulating film 1 .

[0030] 4 and 5 , the lead conductor 10 of the first embodiment is arranged in the nonaqueous electrolyte battery 30 so that the first direction of the conductor 3 extends from the inside to the outside of the sealed container 2. The insulating film 1 is fused to the sealed container 2.

[0031] The first surface of the surface treatment layer of the conductor of the lead conductor of the first embodiment (hereinafter also referred to as the "first surface of the surface treatment layer") that contacts the insulating film includes a region where the arithmetic mean roughness Ra1 in the first direction is 0.05 μm or more and 0.3 μm or less. As a result, even in the early stages of use of the nonaqueous electrolyte battery, the adhesive strength between the first surface of the surface treatment layer and the insulating film is appropriately controlled along the first direction from the inside to the outside of the sealed container, so that if the pressure inside the sealed container increases excessively, the pressure inside the sealed container can be released to the outside. Note that the adhesive strength between the first surface of the surface treatment layer and the insulating film does not increase with use of the nonaqueous electrolyte battery. Therefore, as in the early stages of use, the adhesive strength between the first surface of the surface treatment layer and the insulating film is appropriately controlled along the first direction from the inside to the outside of the sealed container throughout the entire period of use, so that if the pressure inside the sealed container increases excessively, the pressure inside the sealed container can be released to the outside.

[0032] On the other hand, the first surface of the surface treatment layer of the conductor of the lead conductor of the present disclosure has an arithmetic mean roughness Ra2 in the second direction of 0.15 μm or more and 0.8 μm or less, and includes a region where Ra2 is 0.1 μm or more greater than R1. As a result, the adhesive strength in the second direction between the first surface of the surface treatment layer and the insulating film is greater than the adhesive strength in the first direction, resulting in good overall adhesive strength between the first surface of the surface treatment layer and the insulating film, and enabling the nonaqueous electrolyte battery to have good reliability.

[0033] <Conductor> In the lead conductor of embodiment 1, the conductor has a substrate made of copper or a copper alloy and a surface treatment layer provided on the substrate. The conductor may also include a substrate made of copper or a copper alloy and a surface treatment layer provided on the substrate. The shape and dimensions of the conductor 3 are appropriately set depending on the application. The shape of the conductor may be, for example, a rectangular parallelepiped or a strip. The length of the conductor in the first direction may be 10 mm to 150 mm, 20 mm to 100 mm, or 30 mm to 50 mm. The length of the conductor in the second direction may be 5 mm to 200 mm, 15 mm to 140 mm, or 25 mm to 80 mm. The length (corresponding to thickness) of the conductor in a third direction perpendicular to the first and second directions may be 50 μm or more and 1500 μm or less, 100 μm or more and 1000 μm or less, or 150 μm or more and 500 μm or less.

[0034] <<Substrate>> In the lead conductor of the first embodiment, the substrate is made of copper or a copper alloy. This improves the conductivity of the conductor. In the present disclosure, "the substrate is made of copper" means that the substrate is made of pure copper with a copper purity of 99.9% by mass or more. Examples of copper alloys include copper alloys made of copper and at least one element selected from the group consisting of phosphorus (P), zinc (Zn), and tin (Sn). Examples of copper alloys include phosphor bronze. As long as the effects of the present disclosure are not impaired, the substrate may contain impurity elements in addition to copper or a copper alloy. Examples of impurity elements include lead (Pb) and iron (Fe). The content of elements other than copper in the substrate may be, for example, 7.0% by mass or less. When two or more elements other than copper are present in the substrate, the content of elements other than copper refers to the total content of all elements other than copper contained in the substrate. The content of elements other than copper in the base material 4 is measured by high-frequency inductively coupled plasma (ICP) emission spectroscopy.

[0035] The shape of the substrate is appropriately determined depending on the application. For example, the substrate may be a rectangular parallelepiped or a strip. If the substrate is a rectangular parallelepiped, the corners may be tapered.

[0036] The dimensions of the substrate are appropriately set depending on the application. The length of the substrate in the first direction may be 10 mm or more and 150 mm or less. The length of the substrate in the second direction may be 5 mm or more and 200 mm or less. The length of the substrate in the third direction (corresponding to the thickness) may be 50 μm or more and 1500 μm or less.

[0037] The arithmetic mean roughness Ra1 of the substrate surface in the first direction as defined in JIS B 0601:2001 may be 0.5 μm or less, and the arithmetic mean roughness Ra2 in the second direction may be 0.3 μm or less. By using a substrate having such surface properties and adjusting the conditions for forming the surface treatment layer, the Ra1 of the first surface of the surface treatment layer can be 0.05 μm or more and 0.3 μm or less, the Ra2 can be 0.15 μm or more and 0.8 μm or less, and the Ra2 can be 0.1 μm or more greater than the Ra1. The surface properties of the substrate can be adjusted by polishing the surface of the substrate material along the first direction with waterproof paper.

[0038] <Surface Treatment Layer> In the lead conductor of embodiment 1, the surface treatment layer is provided on the substrate. The surface treatment layer may be provided directly on the substrate.

[0039] An insulating film is provided directly on the surface treatment layer. The insulating film may be provided so as to cover the entire surface treatment layer, or may be provided so as to cover a portion of the surface treatment layer. That is, the insulating film is provided directly on at least a portion of the surface treatment layer, and the surface treatment layer and the insulating film are in contact with each other.

[0040] The first surface of the surface treatment layer in contact with the insulating film has an arithmetic mean roughness Ra1 as defined in JIS B 0601:2001 in a first direction of 0.05 μm or more and 0.3 μm or less, an arithmetic mean roughness Ra2 as defined in JIS B 0601:2001 in a second direction perpendicular to the first direction of 0.15 μm or more and 0.8 μm or less, and includes a region where Ra2 is 0.1 μm or more greater than Ra1. In the present disclosure, it is confirmed by the following procedure that the first surface of the surface treatment layer in contact with the insulating film has an arithmetic mean roughness Ra1 as defined in JIS B 0601:2001 in a first direction of 0.05 μm or more and 0.3 μm or less, an arithmetic mean roughness Ra2 as defined in JIS B 0601:2001 in a second direction perpendicular to the first direction of 0.15 μm or more and 0.8 μm or less, and includes a region where Ra2 is 0.1 μm or more greater than Ra1.

[0041] Step 1: A 180° peel test is performed on a lead conductor at 25°C to separate the conductor from the insulating film, exposing the first surface of the surface treatment layer that was in contact with the insulating film. At this time, some of the insulating film may remain on the first surface of the surface treatment layer. To remove the remaining insulating film, the conductor including the surface treatment layer is immersed in a xylene solution at 120°C for 60 minutes.

[0042] Step 2: After removing the conductor from the xylene solution and drying it, the arithmetic mean roughness Ra1 defined in JIS B 0601:2001 in the first direction and the arithmetic mean roughness Ra2 defined in JIS B 0601:2001 in the second direction of the first surface of the surface treatment layer that was in contact with the insulating film are measured. For example, a Keyence VK-X100 (trademark) is used for the measurement. The measurement conditions are as follows: Observation magnification: 50x Analysis length: 0.2 mm Correction: Tilt correction (automatic), curved surface correction (automatic)

[0043] During the measurement, the first surface is divided into a 5 mm x 5 mm grid, and Ra1 and Ra2 are measured for each grid. Depending on the size and shape of the first surface, the first surface may not be divided into an integer number of grids, and the grid may include the first surface and an area adjacent to the first surface. In such cases, the grid consisting only of the first surface is measured, and the grid including the first surface and an area adjacent to the first surface is excluded from the measurement target.

[0044] Step 3: Calculate the percentage (N1 / N) × 100 of the number N1 of first grids where Ra1 is 0.05 μm or more and 0.3 μm or less, Ra2 is 0.15 μm or more and 0.8 μm or less, and Ra2 is 0.1 μm or more greater than Ra1, relative to the total number N of grids. In the present disclosure, when the percentage (N1 / N) × 100 is 60% or more, it is confirmed that the first surface of the surface treatment layer in contact with the insulating film includes a region where the arithmetic mean roughness Ra1 defined in JIS B 0601:2001 in the first direction is 0.05 μm or more and 0.3 μm or less, the arithmetic mean roughness Ra2 defined in JIS B 0601:2001 in the second direction perpendicular to the first direction is 0.15 μm or more and 0.8 μm or less, and Ra2 is 0.1 μm or more greater than Ra1.

[0045] The percentage (N1 / N) x 100 is 60% or more, may be 70% or more, 80% or more, 90% or more, or may be 100%.

[0046] The average Ra1 of the first surface may be 0.05 μm or more and 0.25 μm or less, 0.10 μm or more and 0.20 μm or less, or 0.10 μm or more and 0.15 μm or less. The average Ra1 of the first surface is the sum of the Ra1 of all grids measured in the above procedure 2 divided by the number N of all grids.

[0047] The average Ra2 of the first surface may be 0.25 μm or more and 0.80 μm or less, 0.30 μm or more and 0.60 μm or less, or 0.40 μm or more and 0.60 μm or less. The average Ra2 of the first surface is the sum of the Ra2 of all grids measured in the above procedure 2 divided by the number N of all grids.

[0048] The difference between the average Ra2 of the first surface and the average Ra1 of the first surface (Ra2-Ra1) may be 0.1 μm or more and 1.0 μm or less, 0.15 μm or more and 0.8 μm or less, 0.20 μm or more and 0.6 μm or less, or 0.35 μm or more and 0.55 μm or less.

[0049] The first surface may include a second grid that does not satisfy at least one of the following three conditions: (a) Ra1 is 0.05 μm or more and 0.3 μm or less, (b) Ra2 is 0.15 μm or more and 0.8 μm or less, and (c) Ra2 is 0.1 μm or more greater than Ra1. The Ra1 of the second grid may be 0.01 μm or more and 0.5 μm or less. The Ra2 of the second grid may be 0.01 μm or more and 1.5 μm or less. The difference between the average Ra2 and the average Ra1 of the second grid (Ra2 - Ra1) may be -0.1 μm or more and 1.5 μm or less.

[0050] The first surface of the surface treatment layer in contact with the insulating film may include a region in which the skewness Rsk2 in the second direction defined in JIS B 0601:2001 is greater than 0. Rsk2 may be greater than 0 and less than or equal to 0.7, greater than or equal to 0.2 and less than or equal to 0.7, greater than or equal to 0.4 and less than or equal to 0.7, or greater than or equal to 0.5 and less than or equal to 0.7.

[0051] In the present disclosure, the fact that the first surface of the surface treatment layer in contact with the insulating film includes a region in which the skewness Rsk2 in the second direction as defined in JIS B 0601:2001 is greater than 0 is confirmed by the following procedure. Using the same method as steps 1 and 2 above, first grids are identified on the first surface, with Ra1 being 0.05 μm or more and 0.3 μm or less, Ra2 being 0.15 μm or more and 0.8 μm or less, and Ra2 being 0.1 μm or more greater than Ra1. For each first grid, the skewness Rsk2 in the second direction as defined in JIS B 0601:2001 is measured under the conditions described in step 2. Among the first grids, second grids with Rsk2 greater than 0 are identified. The percentage (N2 / N1) of the number of second grids N2 relative to the number of first grids N1 is calculated as (N2 / N1)×100. In the present disclosure, when the percentage (N2 / N1) × 100 is 60% or more, it is confirmed that the first surface of the surface treatment layer in contact with the insulating film includes a region in which the skewness Rsk2 defined in JIS B 0601:2001 in the second direction is greater than 0.

[0052] The average Rsk2 of the first surface may be greater than 0 and equal to or less than 0.7, equal to or greater than 0.2 and equal to or less than 0.7, equal to or greater than 0.4 and equal to or less than 0.7, or equal to or greater than 0.5 and equal to or less than 0.7. The average Rsk2 of the first surface is the sum of Rsk2 of all grids divided by the number N of all grids.

[0053] In embodiment 1, the average Ra1 of the first surface, the average Ra2 of the first surface, the difference between the average Ra2 of the first surface and the average Ra1 of the first surface (Ra2-Ra1), and the average Rsk2 of the first surface can be any combination of the above ranges.

[0054] In embodiment 1, the first surface of the surface treatment layer in contact with the insulating film may include a region where Ra1 is 0.05 μm or more and 0.3 μm or less, Ra2 is 0.15 μm or more and 0.8 μm or less, and Ra2 is 0.1 μm or more greater than Ra1, and Rsk2 is greater than 0.

[0055] <Metal Layer> In the lead conductor of embodiment 1, the surface treatment layer may include a metal layer containing nickel provided on the substrate. The metal layer may be provided directly on the substrate. The metal layer may be a single layer or may consist of multiple layers. Whether the surface treatment layer includes a metal layer is confirmed by X-ray diffraction. Whether the metal layer is composed of a single layer or multiple layers is confirmed by observing and analyzing the cross-sectional structure of the conductor with a scanning electron microscope.

[0056] The average thickness of the metal layer may be 0.5 μm or more and 5.0 μm or less, 0.8 μm or more and 2.5 μm or less, or 1.0 μm or more and 2.0 μm or less. When the average thickness of the metal layer is 0.5 μm or more, it is possible to prevent the occurrence of exposed portions of the substrate that are not covered by the metal layer. When the average thickness of the metal layer is 5.0 μm or less, in addition to being economically rational, it has the advantage of not impairing the workability of the welding process when incorporating the lead conductor into the nonaqueous electrolyte battery.

[0057] In the present disclosure, the average thickness of the metal layer is measured as follows. The lead conductor is filled with resin and polished along the normal direction of the main surface exposed to the outside of the insulating film to expose the cross section of the lead conductor. The cross section is observed at 20,000x magnification using a scanning electron microscope, and the thickness of the metal layer along the normal direction of the surface of the substrate is measured at five locations. The average thickness of the metal layer at the five locations corresponds to the average thickness of the metal layer in the present disclosure. The average thicknesses of the nickel-phosphorus alloy layer and non-metal layer described below are also measured and calculated in the same manner.

[0058] The metal layer may be composed of one or both of a nickel layer and a nickel alloy layer. The nickel alloy may be composed of nickel and at least one element selected from the group consisting of phosphorus, tin, chromium, molybdenum, and tungsten. The content of elements other than nickel in the metal layer may be 30 mass% or less.

[0059] The metal layer may include a nickel-phosphorus alloy layer having a phosphorus content of 6% by mass or more and 16% by mass or less. The metal layer may consist of a nickel-phosphorus alloy layer having a phosphorus content of 6% by mass or more and 16% by mass or less. The method for measuring the phosphorus content of the nickel-phosphorus alloy layer is as follows. A cross section of the lead conductor is exposed using the same method as the method for measuring the average thickness of the metal layer described above. The cross section is observed at 20,000 times magnification using a scanning electron microscope, and the phosphorus content of the nickel-phosphorus alloy layer is measured by energy dispersive X-ray analysis (EDX). The measurement is performed at five non-overlapping locations. The average of the phosphorus contents at the five locations corresponds to the phosphorus content of the nickel-phosphorus alloy layer in the present disclosure.

[0060] The average thickness of the nickel-phosphorus alloy layer having a phosphorus content of 6% by mass or more and 16% by mass or less may be 0.2 μm or more and 5.0 μm or less, 0.5 μm or more and 2.5 μm or less, or 0.8 μm or more and 2.0 μm or less. When the average thickness of the nickel-phosphorus alloy layer is 0.2 μm or more, corrosion and dissolution of the metal layer in the nonaqueous electrolyte battery can be suppressed. When the average thickness of the nickel-phosphorus alloy layer is 5.0 μm or less, the nickel-phosphorus alloy layer is less likely to crack when the lead conductor is deformed, and corrosion and dissolution of the metal layer in the nonaqueous electrolyte battery can be suppressed.

[0061] In the lead conductor of the first embodiment, the surface treatment layer may include a non-metallic layer containing chromium provided on the metal layer. This improves the resistance of the conductor to electrolytic solutions and suppresses corrosion. Here, "on the metal layer" refers to the surface of the metal layer opposite to the surface facing the substrate.

[0062] The non-metallic layer may be provided directly on the metallic layer. The non-metallic layer may be provided directly on a nickel-phosphorus alloy layer having a phosphorus content of 6% by mass or more and 16% by mass or less. The non-metallic layer may be a single layer or may consist of multiple layers. The presence of a non-metallic layer in the surface treatment layer is confirmed by X-ray photoelectron spectroscopy.

[0063] The non-metallic layer may be a layer containing chromium hydroxide. The chromium content of the non-metallic layer is less than 1 mg / m ２ 20mg / m or more ２ It may be less than 2 mg / m ２15mg / m or more ２ It may be less than 3 mg / m ２ 10mg / m or more ２ The chromium content of the non-metallic layer may be 1 mg / m or less. ２ When the chromium content of the non-metallic layer is 20 mg / m or more, the resistance of the conductor to the electrolytic solution is further improved. ２ When the chromium content is equal to or less than 100%, cohesive failure within the non-metallic layer can be suppressed, and the adhesive strength between the first surface and the insulating film can be improved. The chromium content of the non-metallic layer is measured by ICP mass spectrometry.

[0064] The non-metallic layer may contain an organic material. The non-metallic layer may contain a transition metal compound other than chromium.

[0065] <Insulating Film> The width of the insulating film 1 in the second direction of the conductor 3 is wider than the width of the conductor 3 in the second direction. The insulating film 1 is attached by adhesion or fusion to the outer peripheral surface of the conductor 3 so as to protrude from both ends of the conductor 3 in the second direction, and the insulating films 1 protruding from both ends of the conductor 3 are attached to each other by adhesion or fusion. The length of the insulating film 1 in the first direction of the conductor 3 is shorter than the length of the conductor 3 in the first direction. The insulating film 1 is not attached to the first end 3a and the second end 3b of the conductor 3.

[0066] The average thickness of the insulating film may be 40 μm or more and 500 μm or less, 80 μm or more and 500 μm or less, 100 μm or more and 300 μm or less, or 120 μm or more and 250 μm or less.

[0067] In the present disclosure, the average thickness of an insulating film is measured as follows. The lead conductor is filled with resin and polished along the normal direction of the main surface exposed to the outside of the insulating film to expose the cross section of the lead conductor. The cross section is observed at 500x magnification using a microscope, and the thickness of the insulating film is measured at five points along the normal direction of the surface of the substrate. The average thickness of the insulating film at the five points corresponds to the average thickness of the insulating film in the present disclosure. In the present disclosure, the average thicknesses of the first insulating layer, second insulating layer, and third insulating layer described below are also measured in a similar manner.

[0068] <First Insulating Layer> In the lead conductor 10 of embodiment 1, the insulating film 1 may include a first insulating layer 1a arranged in contact with the conductor 3. The first insulating layer may be made of an acid-modified polypropylene layer. Examples of acid-modified groups include maleic anhydride. When the first insulating layer is an acid-modified polypropylene layer, the first insulating layer has good adhesion and sealing properties with the conductor. The acid-modified polypropylene layer may contain unmodified polypropylene as well as acid-modified polypropylene as a resin component, as long as the effects of the present disclosure are not impaired. Hereinafter, acid-modified polypropylene and unmodified polypropylene will be collectively referred to as polypropylene.

[0069] The presence of an acid-modified group in the first insulating layer and the presence of polypropylene in the first insulating layer can be confirmed by removing only the first insulating layer from the lead conductor and performing transmission light analysis on the first insulating layer using a Fourier transform infrared spectrophotometer.

[0070] In the insulating film of embodiment 1, the average thickness of the first insulating layer may be 20 μm or more and 150 μm or less, 25 μm or more and 120 μm or less, or 30 μm or more and 100 μm or less. When the average thickness of the first insulating layer is 20 μm or more, the first insulating layer is less likely to be damaged due to being too thin, and good adhesion to the conductor can be ensured. When the average thickness of the first insulating layer is 150 μm or less, the insulating film can be made thinner, and nonaqueous electrolyte batteries including the insulating film can be made smaller.

[0071] In the lead conductor of the first embodiment, the first insulating layer may contain various additives such as a flame retardant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a lubricant, a colorant, etc. The types and amounts of these additives may be similar to those used in conventionally known acid-modified polypropylene layers.

[0072] <<Second Insulating Layer>> In the lead conductor 10 of the first embodiment, the insulating film 1 may include a second insulating layer 1b provided on the surface of the first insulating layer 1a opposite to the surface in contact with the conductor 3. The insulating film 1 may be composed of the first insulating layer 1a and the second insulating layer 1b. The second insulating layer may be composed of a heat-resistant resin layer. If the second insulating layer is a heat-resistant resin layer, the second insulating layer does not melt during thermocompression bonding between the insulating film and the conductor, and therefore the second insulating layer is excellent as a support.

[0073] When the second insulating layer is a heat-resistant resin layer, examples of the heat-resistant resin include polyolefin resins, polyethylene terephthalate, polyamide, and fluororesin. Among these, polyolefin resins have good adhesion to the first insulating layer, which is made of an acid-modified polypropylene layer. Examples of polyolefin resins include polyethylene, polypropylene, cross-linked polypropylene, ionomer resins, and acid-modified polyolefins. In particular, the second insulating layer may contain homopolypropylene, which is a type of polypropylene. The second insulating layer may be a homopolypropylene layer. Homopolypropylene does not melt during thermocompression bonding between the adhesive film and the conductor, and therefore functions well as a support. The second insulating layer may contain polyester nonwoven fabric.

[0074] Whether the second insulating layer contains a heat-resistant resin can be confirmed by removing only the second insulating layer from the lead conductor and performing transmission light analysis on the second insulating layer using a Fourier transform infrared spectrophotometer.

[0075] In the insulating film of embodiment 1, the average thickness of the second insulating layer may be 20 μm or more and 150 μm or less, 25 μm or more and 120 μm or less, or 30 μm or more and 100 μm or less. When the average thickness of the second insulating layer is 20 μm or more, the second insulating layer is less likely to be too thin and break, and good adhesion to the conductor can be ensured. When the average thickness of the second insulating layer is 150 μm or less, the insulating film can be made thinner, and nonaqueous electrolyte batteries including the insulating film can be made smaller.

[0076] In the lead conductor of the first embodiment, the second insulating layer may contain various additives such as a flame retardant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a lubricant, a colorant, etc. The types and amounts of these additives may be the same as those used in conventionally known heat-resistant resin layers.

[0077] <Third Insulating Layer> The insulating film of embodiment 1 may include a third insulating layer in addition to the first insulating layer and the second insulating layer. The insulating film of embodiment 1 may be composed of a first insulating layer, a second insulating layer, and a third insulating layer. An example of the third insulating layer is a layer that serves to improve adhesion to an enclosed container containing aluminum foil. The third insulating layer may be a single layer, or two or more layers may be combined. The position of the third insulating layer is appropriately selected depending on the type of the third insulating layer.

[0078] The insulating film may include a first insulating layer, a second insulating layer provided on the surface of the first insulating layer opposite to the surface that contacts the conductor, and a third insulating layer provided on the surface of the second insulating layer opposite to the surface that faces the first insulating layer.

[0079] In the insulating film 1 of embodiment 1, the average thickness of the third insulating layer may be 20 μm or more and 100 μm or less, 30 μm or more and 70 μm or less, or 35 μm or more and 60 μm or less.

[0080] In the present disclosure, the third insulating layer may contain various additives such as a flame retardant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a lubricant, a colorant, etc. The types and amounts of these additives may be the same as those used in conventionally known third insulating layers.

[0081] 4 and 5 , a nonaqueous electrolyte battery 30 according to an embodiment of the present disclosure (hereinafter also referred to as “Embodiment 2”) includes an enclosed container 2 and the lead conductor 10 according to Embodiment 1 arranged to extend from the inside to the outside of the enclosed container 2. An insulating film 1 is fused to the enclosed container 2.

[0082] The nonaqueous electrolyte battery 30 of the second embodiment includes a battery cell 15 including a positive electrode 20, a negative electrode 14, and an electrolyte 13 sandwiched between the positive electrode 20 and the negative electrode 14, a conductor 3 electrically connected to each of the positive electrode 20 and the negative electrode 14, and an enclosure 2 that seals the battery cell 15. A portion of the conductor 3 is exposed to the outside of the enclosure 2, and an insulating film 1 is disposed between the conductor 3 and the enclosure 2. A first insulating layer 1a of the insulating film 1 is disposed in contact with the conductor 3.

[0083] As shown in FIG. 5 , the sealed container 2 is made of a three-layer laminate film 8 consisting of a metal layer 16 and first and second resin layers 17 and 18 that coat the metal layer 16. The metal layer 16 is formed from a metal such as aluminum foil. The second resin layer 18, located on the exterior side of the sealed container 2, can be made of polyamide resins such as 6,6-nylon or 6-nylon, polyester resins, polyimide resins, etc. Furthermore, the first resin layer 17, located on the interior side of the sealed container 2, is preferably made of an insulating resin that is insoluble in nonaqueous electrolytes and melts when heated. Examples of insulating resins include polyolefin resins, acid-modified polyolefin resins, and acid-modified styrene-based elastomers. The sealed container 2 is fabricated by overlapping two laminate films 8 and heat-sealing the three edges excluding the edge through which the conductor passes. At the outer periphery of the sealed container 2, the two metal layers 16 are bonded via the first resin layer 17.

[0084] The conductor is bonded (thermally fused) to the sealed container 2 (laminate film 8) via the insulating film 1 at a seal portion 9. Further enclosed inside the nonaqueous electrolyte battery 30 are a positive electrode 20, a negative electrode 14, and an electrolyte 13 connected to the ends of the conductor.

[0085] The electrolyte 13 is a non-aqueous electrolyte. For example, LiPF ６ , LiBF ４ Examples of suitable lithium salts include those obtained by dissolving fluorine-containing lithium salts such as those mentioned above in diethyl carbonate (DEC), dimethyl carbonate (DMC), propylene carbonate (PC), or the like.

[0086] The present embodiment will be described in more detail with reference to examples, although the present embodiment is not limited to these examples.

[0087] [Sample 1] <<Preparation of Conductor>> A substrate material was prepared by rolling an oxygen-free copper plate (C1020) to a thickness of 0.2 mm and processing it into a length of 45 mm and a width of 45 mm. The substrate material included a first surface and a second main surface opposite to the first surface. The first surface had an arithmetic mean roughness Ra1 in the first direction of 0.15 μm, an arithmetic mean roughness Ra2 in the second direction of 0.2 μm, and a skewness Rsk2 in the second direction of 0.8.

[0088] As a first treatment, the second main surface of the substrate material was fixed to a jig with double-sided tape, and the entire first surface was polished along a first direction using waterproof sandpaper with No. 1000 to obtain a substrate. The arithmetic mean roughness Ra1 in the first direction, the arithmetic mean roughness Ra2 in the second direction, and the skewness Rsk2 in the second direction of the surface of the substrate after polishing are shown in Table 1.

[0089] Next, as a second treatment, the substrate was immersed in a sodium hydroxide aqueous solution (concentration: 40 g / L) at 25°C, and the current density was 1.0 A / dm ２ After degreasing, the substrate was washed with running water.

[0090] Next, as a third treatment, the washed substrate was immersed for 30 seconds in an aqueous sulfuric acid solution (concentration: 10% by mass) at 25° C. to perform acid activation. After acid activation, the substrate was washed with running water.

[0091] Next, as a fourth treatment, nickel sulfate hexahydrate (concentration: 500 g / L), nickel chloride hexahydrate (concentration: 30 g / L), Novoplate HS (manufactured by Atotech Japan Co., Ltd., concentration: 100 mL / L), and boric acid (concentration: 30 g / L) were mixed to obtain a nickel-phosphorus alloy plating solution. The acid-activated substrate was immersed in the nickel-phosphorus alloy plating solution at 65°C, and a current density of 10.0 A / dm ２ The substrate was then washed with running water after nickel-phosphorus alloy plating.

[0092] Next, as a fifth treatment, chromium chloride hexahydrate (5.0 g / L) and potassium formate (170 g / L) were mixed with pure water to obtain a surface treatment solution. The nickel-phosphorus alloy-plated substrate was immersed in the surface treatment solution at 45°C, and a current density of 10 A / dm ２ The substrate was subjected to cathodic electrolysis at 400° C. for 30 seconds to form a chromium-containing non-metallic layer on the metal layer. After cathodic electrolysis, the substrate was washed with running water.

[0093] Through the above steps, a conductor having a surface treatment layer formed on a substrate was obtained.

[0094] <<Preparation of insulating film>> Acid-modified polypropylene was prepared as the raw material for the first insulating layer, homopolypropylene was prepared as the raw material for the second insulating layer, and random polypropylene was prepared as the raw material for the third insulating layer. The raw materials for the first insulating layer, the second insulating layer, and the third insulating layer were each mixed using a mixer to obtain a mixed raw material.

[0095] Using a coat hanger-type three-kind, three-layer T-die film-forming machine equipped with three single-screw extruders, the mixed raw materials for the first insulating layer were fed into the first extruder, the mixed raw materials for the second insulating layer into the second extruder, and the mixed raw materials for the third insulating layer into the third extruder, and co-extruded to obtain an insulating film in which an acid-modified polypropylene layer (corresponding to the first insulating layer), a homopolypropylene layer (corresponding to the second insulating layer), and a random polypropylene layer (corresponding to the third insulating layer) were laminated in the above order. The average thickness of the first insulating layer was 50 μm, the average thickness of the second insulating layer was 50 μm, and the average thickness of the third insulating layer was 50 μm.

[0096] <<Preparation of Test Samples>> Next, the obtained insulating film was cut into a size of 55 mm in length and 10 mm in width. The cut insulating film was placed on the surface of the first surface side of the conductor substrate so that the longitudinal direction was parallel to the second direction of the conductor surface, and heat-sealed under conditions of a mold temperature of 220°C and a surface pressure of 0.3 MPa. In this way, test samples were obtained.

[0097] [Sample 2] A test sample was obtained using the same procedure as Sample 1, except that in the first treatment, a rectangular area of ​​the first surface measuring 45 mm in length in the first direction and 40.5 mm in length in the second direction was polished, and in the fourth treatment, the nickel-phosphorus alloy plating time was set to 15 seconds.

[0098] [Sample 3] A test sample was obtained in the same manner as Sample 1, except that in the fourth treatment, the Novoplate HS concentration was 50 mL / L and the nickel-phosphorus alloy plating time was 80 seconds.

[0099] [Sample 4] A test sample was obtained in the same manner as Sample 1, except that the fifth treatment was not carried out.

[0100] [Sample 5] A test sample was obtained using the same procedure as Sample 1, except that #2000 waterproof paper was used in the first treatment and a rectangular area of ​​45 mm in the first direction and 36 mm in the second direction was polished on the first surface. Table 1 shows the arithmetic mean roughness Ra1 in the first direction, the arithmetic mean roughness Ra2 in the second direction, and the skewness Rsk2 in the second direction of the surface of the substrate after polishing.

[0101] [Sample 6] A test sample was obtained using the same procedure as Sample 1, except that No. 600 waterproof paper was used in the first treatment and a rectangular area of ​​45 mm in the first direction and 40.5 mm in the second direction was polished on the first surface. Table 1 shows the arithmetic mean roughness Ra1 in the first direction, the arithmetic mean roughness Ra2 in the second direction, and the skewness Rsk2 in the second direction of the polished surface of the substrate.

[0102] [Sample 7] A test sample was obtained using the same procedure as Sample 1, except that in the fourth treatment, nickel plating was performed instead of nickel-phosphorus alloy plating to form a metal layer made of nickel. The nickel plating solution was prepared by mixing nickel amidosulfate tetrahydrate (concentration: 500 g / L), nickel chloride hexahydrate (concentration: 30 g / L), and boric acid (concentration: 30 g / L). The substrate was immersed in the plating solution at 55°C, and a current density of 5.0 A / dm ２ Nickel plating was carried out at 100°C for 90 seconds.

[0103] [Sample 8] A test sample was obtained using the same procedure as Sample 1, except that in the first treatment, a rectangular area of ​​the first surface measuring 45 mm in length in the first direction and 40.5 mm in length in the second direction was polished, and the fourth treatment and the fifth treatment were not performed.

[0104] [Sample 9] A test sample was obtained using the same procedure as Sample 1, except that No. 600 waterproof sandpaper was used in the first treatment, the nickel-phosphorus alloy plating time was 40 seconds in the fourth treatment, and a rectangular area measuring 45 mm in the first direction and 36 mm in the second direction was polished on the first surface. Table 1 shows the arithmetic mean roughness Ra1 in the first direction, the arithmetic mean roughness Ra2 in the second direction, and the skewness Rsk2 in the second direction of the polished surface of the substrate.

[0105] [Sample 10] A test sample was obtained using the same procedure as Sample 8, except that in the first treatment, a rectangular area of ​​the first surface measuring 45 mm in length in the first direction and 27 mm in length in the second direction was polished.

[0106] [Sample 1-1] In preparing the test sample, the insulating film was placed on the surface of the first side of the conductor substrate so that the longitudinal direction of the insulating film was parallel to the first direction of the conductor surface, and heat-sealed in this state. A test sample was obtained using the same procedure as Sample 1.

[0107] [Sample 1-2] A test sample was obtained in the same manner as Sample 1, except that No. 600 waterproof paper was used in the first treatment and the nickel-phosphorus alloy plating time was set to 15 seconds in the fourth treatment.

[0108]

[0109] <Evaluation> <Measurement of phosphorus content in metal layer and chromium content in non-metal layer> For each sample, the phosphorus content in the metal layer made of a nickel-phosphorus alloy and the chromium content in the non-metal layer were measured by the method described in embodiment 1. The results are shown in Table 1.

[0110] <<Measurement of the Surface Shape of the Conductor>> For each test sample, the conductor and the insulating film were separated by a 180° peel test at 120° C. to expose the first surface of the surface treatment layer. The conductor including the surface treatment layer was immersed in a xylene solution at 120° C. for 60 minutes to remove part of the insulating film remaining on the conductor.

[0111] The conductor was removed from the xylene solution and dried, and then the arithmetic mean roughness Ra1 in the first direction, the arithmetic mean roughness Ra2 in the second direction, and the skewness Rsk2 in the second direction of the first surface of the surface treatment layer were measured. The specific measurement methods are as described in embodiment 1.

[0112] Table 2 shows the percentage (N1 / N) × 100 of the number N1 of first grids for which Ra1 is 0.05 μm or more and 0.3 μm or less, Ra2 is 0.15 μm or more and 0.8 μm or less, and Ra2 is 0.1 μm or more greater than Ra1, relative to the number N of all grids for each sample.

[0113] Table 2 shows the average Ra1 of the first surface (shown as "Ra1" in Table 2), the average Ra2 of the first surface (shown as "Ra2" in Table 2), the difference between the average Ra2 of the first surface and the average Ra1 of the first surface (Ra2 - Ra1) (shown as "Ra2 - Ra1" in Table 2), and the average Rsk2 of the first surface (shown as "Rsk2" in Table 2) for each sample.

[0114]

[0115] Evaluation of Initial Adhesion One hour after the production of the test sample, the adhesive strength P1 between the conductor and the insulating film in the first direction and the adhesive strength P2 between the conductor and the insulating film in the second direction were measured by a 180° peel test at 120°C. The tensile speed was 50 mm / min. The results are shown in Table 3. When P1 was 4 N / cm or more and 6 N / cm or less, P2 was 6 N / cm or more and 10 N / cm or less, and the difference between P2 and P1 (P2 - P1) was 1 or more, the test sample was judged to have an appropriately controlled adhesive strength between the conductor and the insulating film along the first direction during initial use, to be easily peeled from the conductor and the insulating film along the first direction, and to have good overall adhesive strength between the conductor and the insulating film.

[0116]

[0117] <Evaluation of Adhesion Strength After Aging> The adhesion strength after aging of Samples 1, 6, and 9 was evaluated by the following method.

[0118] A mixed solution was prepared by mixing ethylene carbonate, diethyl carbonate, and dimethyl carbonate in a volume ratio of 1:1:1. The mixed solution was added with lithium hexafluorophosphate (LiPF ６ A test solution was prepared by dissolving 1.0 mol / L of ethylenediaminetetraacetic acid (ETA) in a 1000 ppm aqueous solution, and adding water to the 1000 ppm aqueous solution. Each test specimen was immersed in the test solution and left in a thermostatic chamber at 85°C for four weeks. The test specimen was then removed from the test solution, and the adhesive strength Q1 between the conductor and the insulating film in the first direction and the adhesive strength Q2 between the conductor and the insulating film in the second direction were measured using a 180° peel test at 25°C. The tensile speed was 50 mm / min. The results are shown in Table 4. When Q1 is 4 N / cm or more and 6 N / cm or less, Q2 is more than 6 N / cm and 10 N / cm or less, and the difference between Q2 and Q1 (Q2 - Q1) is 1 or more, the test specimen is judged to have an appropriately controlled adhesive strength between the conductor and the insulating film after aging, to be easily peeled from the insulating film in the first direction, and to have good overall adhesive strength between the conductor and the insulating film.

[0119]

[0120] <Discussion> Samples 1 to 10 correspond to Examples. Samples 1-1 and 1-2 correspond to Comparative Examples. From the results of the initial adhesive strength of Samples 1 to 10, it was confirmed that the adhesive strength between the conductor and the insulating film along the first direction at the beginning of use was appropriately controlled, the conductor and the insulating film were easily peeled off, and the overall adhesive strength between the conductor and the insulating film was good. Therefore, when the lead conductors fabricated using the conductors and insulating films of Samples 1 to 9 are used in nonaqueous electrolyte batteries, even at the beginning of use of the nonaqueous electrolyte battery, the adhesive strength between the conductor and the insulating film along the direction from the inside to the outside of the sealed container is appropriately controlled, the bonded portion between the lead conductor and the sealed container is easily peeled off, and the overall adhesive strength between the conductor and the insulating film is good.

[0121] The results of the post-aging adhesive strength for Samples 1, 6, and 9 confirmed that the adhesive strength between the conductor and the insulating film was appropriately controlled along the first direction after aging, the conductor and the insulating film were easily peeled off, and the overall adhesive strength between the first surface of the surface treatment layer and the insulating film was good. Therefore, when the lead conductors made using the conductors and insulating films of Samples 1 and 6 are used in nonaqueous electrolyte batteries, the adhesive portion between the lead conductor and the sealed container is easily peeled off along the direction from the inside to the outside of the sealed container over a long period of time during use of the nonaqueous electrolyte battery, and the overall adhesive strength between the conductor and the insulating film is good.

[0122] The results of the initial adhesive strength confirmed that Samples 1-1 and 1-2 were not likely to peel along the first direction in the early stages of use. Therefore, when the lead conductors made using the conductors and insulating films of Samples 1-1 and 1-2 are used in nonaqueous electrolyte batteries, the adhesive portion between the lead conductor and the sealed container is not likely to peel along the direction from the inside to the outside of the sealed container in the early stages of use of the nonaqueous electrolyte battery.

[0123] Although the embodiments and examples of the present disclosure have been described above, it is intended from the beginning that the configurations of the above-described embodiments and examples may be appropriately combined and modified in various ways. The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims, not by the above-described embodiments and examples, and is intended to include meanings equivalent to the claims and all modifications within the scope of the claims.

[0124] REFERENCE SIGNS LIST 1 insulating film, 1a first insulating layer, 1b second insulating layer, 2 sealed container, 3 conductor, 3a first end, 3b second end, 4 substrate, 5 metal layer, 6 non-metal layer, 7 surface treatment layer, 7a first surface, 8 laminate film, 9 sealing portion, 10 lead conductor, 13 electrolyte, 14 negative electrode, 15 battery cell, 16 metal layer, 17 first resin layer, 18 second resin layer, 20 positive electrode, 30 non-aqueous electrolyte battery.

Claims

1. A lead conductor comprising: a conductor extending in a first direction; and an insulating film covering an outer peripheral surface of the conductor between the first end and the second end of the conductor while exposing a first end of the conductor in the first direction and a second end of the conductor opposite the first end when viewed along the first direction, wherein the conductor has a base made of copper or a copper alloy and a surface treatment layer provided on the base, the insulating film is provided directly on the surface treatment layer, and a first surface of the surface treatment layer in contact with the insulating film has an arithmetic mean roughness Ra1 in the first direction as specified in JIS B 0601:2001 of 0.05 μm or more and 0.3 μm or less, and an arithmetic mean roughness Ra2 in a second direction perpendicular to the first direction as specified in JIS B 0601:2001 of 0.15 μm or more and 0.8 μm or less, A lead conductor including a region in which the Ra2 is greater than the Ra1 by 0.1 μm or more.

2. The lead conductor according to claim 1, wherein the first surface includes an area in which the skewness Rsk2 defined in JIS B 0601:2001 in the second direction is greater than 0.

3. The lead conductor according to claim 1 or claim 2, wherein the surface treatment layer comprises a metal layer containing nickel provided on the base material, and a non-metal layer containing chromium provided on the metal layer.

4. The lead conductor according to claim 3, wherein the average thickness of the metal layer is 0.5 μm or more and 5.0 μm or less.

5. A lead conductor as claimed in claim 3 or claim 4, wherein the metal layer includes a nickel-phosphorus alloy layer having a phosphorus content of 6% by mass or more and 16% by mass or less, and the non-metallic layer is provided directly on the nickel-phosphorus alloy layer.

6. The lead conductor according to claim 5, wherein the average thickness of the nickel-phosphorus alloy layer is 0.2 μm or more and 5.0 μm or less.

7. The chromium content of the non-metallic layer is 1 mg / m ２ 20mg / m or more ２ 7. The lead conductor according to claim 3, wherein:

8. A lead conductor as claimed in any one of claims 1 to 7, wherein the insulating film includes a first insulating layer provided in contact with the conductor, and a second insulating layer provided on the surface of the first insulating layer opposite to the surface in contact with the conductor, the first insulating layer being an acid-modified polypropylene layer, and the second insulating layer being a heat-resistant resin layer.

9. A non-aqueous electrolyte battery comprising: an enclosed container; and the lead conductor according to any one of claims 1 to 8, which is arranged so as to extend from the inside to the outside of the enclosed container, wherein the insulating film is fused to the enclosed container.

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