WO2022107603A1 - Current collector - Google Patents

Current collector Download PDF

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Publication number
WO2022107603A1
WO2022107603A1 PCT/JP2021/040561 JP2021040561W WO2022107603A1 WO 2022107603 A1 WO2022107603 A1 WO 2022107603A1 JP 2021040561 W JP2021040561 W JP 2021040561W WO 2022107603 A1 WO2022107603 A1 WO 2022107603A1
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WIPO (PCT)
Prior art keywords
current collector
resin layer
conductive resin
layer
thickness
Prior art date
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PCT/JP2021/040561
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French (fr)
Japanese (ja)
Inventor
宗一郎 山中
一彰 大西
亮 西岡
靖泰 都藤
愛美 中山
拓哉 中村
祐一郎 横山
英明 堀江
Original Assignee
グンゼ株式会社
Apb株式会社
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Application filed by グンゼ株式会社, Apb株式会社 filed Critical グンゼ株式会社
Priority to CN202180078092.3A priority Critical patent/CN116569366A/en
Publication of WO2022107603A1 publication Critical patent/WO2022107603A1/en

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/64Carriers or collectors
    • H01M4/66Selection of materials
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Definitions

  • the present invention relates to a current collector, and more particularly to a current collector for a lithium ion battery.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2018-55967 is for a lithium ion battery including a first conductive resin layer containing a first conductive filler and a second conductive resin layer containing a second conductive filler. Disclose the current collector.
  • the first conductive filler is conductive carbon and the second conductive filler is selected from the group containing platinum, gold, silver, copper, nickel and titanium. Contains at least one metal element.
  • the current collector may be pressed.
  • the present inventors have found that when a current collector as disclosed in Patent Document 1 is pressed, the penetration resistance value of the current collector increases.
  • the present invention has been made to solve such a problem, and an object of the present invention is to provide a current collector capable of suppressing an increase in penetration resistance value due to press working.
  • the current collector according to the present invention is a current collector for a lithium ion battery.
  • This current collector includes a first conductive resin layer and a second conductive resin layer.
  • the first conductive resin layer contains the first conductive filler.
  • the second conductive resin layer is formed on the first conductive resin layer and contains the second conductive filler.
  • the first conductive filler is conductive carbon.
  • the second conductive filler contains at least one metal selected from the group containing platinum, gold, silver, copper, SUS (Stainless Used Steel), nickel and titanium.
  • the thickness of the first conductive resin layer is 50% or more of the thickness of the current collector.
  • the present inventors have found that by increasing the thickness of the first conductive resin layer, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
  • the thickness of the first conductive resin layer is 50% or more of the thickness of the current collector. Therefore, according to this current collector, since the thickness of the first conductive resin layer is relatively thick, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
  • the thickness of the first conductive resin layer may be 67% or more of the thickness of the current collector.
  • the thickness of the first conductive resin layer may be 75% or more of the thickness of the current collector.
  • the second conductive resin layer may include a first layer close to the first conductive resin layer and a second layer far from the first conductive resin layer.
  • the second conductive resin layer includes the first layer and the second layer. Therefore, according to this current collector, the mass percent concentration of the metal can be changed between the first layer and the second layer. As a result, according to this current collector, the mass percent concentration of the metal can be appropriately adjusted for each layer.
  • the second conductive filler may contain nickel.
  • the mass percent concentration of the metal in the second layer may be higher than the mass percent concentration of the metal in the first layer.
  • the present inventors have found that the higher the mass percent concentration of the metal in the second layer, the more it is possible to suppress the increase in the penetration resistance value of the current collector due to press working.
  • the mass percent concentration of the metal in the second layer is higher than the mass percent concentration of the metal in the first layer. Therefore, according to this current collector, since the mass percent concentration of the metal in the second layer is relatively high, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
  • FIG. 1 is a diagram showing a cross section of a current collector 10 according to the present embodiment.
  • the current collector 10 is used, for example, as a current collector for the negative electrode of a lithium ion battery.
  • the current collector 10 includes a first conductive resin layer 100 and a second conductive resin layer 200.
  • the active material for the negative electrode is applied above the second conductive resin layer 200, and the current collector for the positive electrode is arranged below the first conductive resin layer 100.
  • the current collector 10 is pressed with the active material for the negative electrode coated on the current collector 10.
  • a current flows in the penetrating direction (vertical direction in the figure) of the current collector 10.
  • the thickness (T1) of the first conductive resin layer 100 is 50% or more and 90% or less of the thickness (T2) of the current collector 10.
  • the thickness (T1) of the first conductive resin layer 100 is 67% or more of the thickness (T2) of the current collector 10, and more preferably, the thickness of the first conductive resin layer 100 is collected. It is 75% or more of the thickness of the electric body 10.
  • each layer will be described.
  • the first conductive resin layer 100 contains a polyolefin and a conductive filler. That is, the first conductive resin layer 100 is formed by mixing polyolefin and a conductive filler.
  • polystyrene resin examples include polypropylene (PP) and polyethylene (PE). Further, a polymer or the like containing an ⁇ -olefin having 4 to 30 carbon atoms (1-butene, isobutene, 1-hexene, 1-decene, 1-dodecene, etc.) as an essential constituent monomer may be used as the polyolefin. .. These polyolefins may be one kind alone or a mixture of two or more kinds.
  • polypropylene is preferable from the viewpoint of moisture-proof properties and mechanical strength.
  • examples of polypropylene include homopolypropylene, random polypropylene, block polypropylene, polypropylene having a long-chain branched structure, and acid-modified polypropylene.
  • Homopolypropylene is a homopolymer of propylene.
  • Random polypropylene is a copolymer containing a small amount (preferably 4.5% by weight or less) of ethylene units introduced irregularly.
  • Block polypropylene is a composition in which ethylene propylene rubber (EPR) is dispersed in homopolypropylene, and has a "sea island structure" in which "islands” containing EPR float in the "sea” of homopolypropylene. There is.
  • EPR ethylene propylene rubber
  • the acid-modified polypropylene can be obtained through a known method such as reacting an unsaturated carboxylic acid such as maleic anhydride with polypropylene in the presence of an organic peroxide.
  • Examples of the conductive filler contained in the first conductive resin layer 100 include conductive carbon.
  • Examples of the conductive carbon include graphite, carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), carbon nanotubes, and mixtures thereof.
  • carbon black is preferable, and acetylene black, furnace black, or a mixture thereof is more preferable.
  • the volume average particle size of carbon black is not particularly limited, but is preferably 3 to 500 nm from the viewpoint of the electrical characteristics of the lithium ion battery in which the current collector 10 is used.
  • the second conductive resin layer 200 is formed on the first conductive resin layer 100, and includes the first layer 210 and the second layer 220.
  • Each of the first layer 210 and the second layer 220 contains a polyolefin and a conductive filler. That is, each of the first layer 210 and the second layer 220 is formed by mixing polyolefin and a conductive filler.
  • the polyolefin for example, those exemplified in the description of the first conductive resin layer 100 can be used.
  • Examples of the conductive filler contained in the second conductive resin layer 200 include platinum, gold, silver, copper, SUS (Stainless Used Steel), nickel, titanium and a mixture thereof. That is, the conductive filler contained in the second conductive resin layer 200 contains at least one metal selected from the group containing platinum, gold, silver, copper, SUS, nickel and titanium. Among these, nickel particles are more preferable as the conductive filler.
  • the mass percent concentration of the conductive filler (metal element) in the first layer 210 is 70 wt% or more. Therefore, in the current collector 10, even if the temperature of the first conductive resin layer 100 rises and the first layer 210 expands with the temperature rise, the mass percent concentration of the conductive filler of the first layer 210 Therefore, the contact between the conductive fillers is easily maintained. Therefore, according to the current collector 10, it is possible to suppress an increase in the resistance value of the second conductive resin layer 200 with an increase in the temperature of the first conductive resin layer 100.
  • the mass percent concentration of the conductive filler (metal) in the second layer 220 is 60 wt% or more. Since the mass percent concentration of the conductive filler in the second layer 220 is high to some extent, it is difficult to cut the conductive path between the conductive fillers in the second layer 220 even if the current collector 10 is pressed. As a result, according to the current collector 10, it is possible to suppress an increase in the penetration resistance value due to press working.
  • the mass percent concentration of the conductive filler in the second layer 220 may be higher than the mass percent concentration of the conductive filler in the first layer 210. According to the current collector 10, since the mass percent concentration of the conductive filler in the second layer 220 is relatively high, it is possible to suppress an increase in the penetration resistance value of the current collector 10 due to press working.
  • the thickness (T1) of the first conductive resin layer 100 is 50% or more of the thickness (T2) of the current collector 10. As described above, in the current collector 10, the thickness of the first conductive resin layer 100 is relatively thick. Hereinafter, the reason why the first conductive resin layer 100 is thick will be described.
  • the current collector may be pressed.
  • the present inventors have noticed that, depending on the configuration of the current collector, the penetration resistance value of the current collector increases when the current collector is pressed.
  • the present inventors have found that by increasing the thickness of the first conductive resin layer 100, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
  • the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10. Therefore, according to the current collector 10, since the thickness of the first conductive resin layer 100 is relatively thick, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
  • the present inventors have also found other merits by increasing the thickness of the first conductive resin layer 100.
  • the temperature of the current collector rises during the use of the lithium-ion battery. As the temperature of the current collector rises, the penetration resistance value of the current collector also rises.
  • the present inventors have found that by increasing the thickness of the first conductive resin layer 100, an increase in the penetration resistance value of the current collector 10 accompanying an increase in the temperature of the current collector 10 is suppressed. I found it. Further, the present inventors have found that the tear strength of the current collector 10 is increased by increasing the thickness of the first conductive resin layer 100. These will be described in detail later through Examples described later.
  • the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10. Further, the present inventor (or others) suppresses curling of the current collector 10 such that the first conductive resin layer 100 is wound inward by increasing the thickness of the first conductive resin layer 100. I found.
  • FIG. 2 is a diagram schematically showing the manufacturing apparatus 500 of the current collector 10. As shown in FIG. 2, the manufacturing apparatus 500 includes a T-die unit 510 and a raw material input unit 520, 530, 540.
  • a conductive resin raw material for forming the second layer 220 of the second conductive resin layer 200 is charged into the raw material charging section 520.
  • a conductive resin raw material for forming the first layer 210 of the second conductive resin layer 200 is charged into the raw material charging section 530.
  • a conductive resin raw material for forming the first conductive resin layer 100 is charged into the raw material charging section 540.
  • the T-die portion 510 coextrudes the raw materials charged through the raw material charging parts 520, 530, and 540 to fuse the melts of the conductive resin raw materials into one integrated film. It is configured as follows. That is, the T-die unit 510 is configured to generate a film-shaped current collector 10 based on the raw material input via the raw material input units 520, 530, and 540. As described above, the current collector 10 is manufactured, for example, by laminating the first conductive resin layer 100, the first layer 210, and the second layer 220 by the manufacturing apparatus 500.
  • the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10. Therefore, according to the current collector 10, since the thickness of the first conductive resin layer 100 is relatively thick, it is possible to suppress an increase in the penetration resistance value of the current collector 10 due to press working.
  • the second conductive resin layer 200 includes the first layer 210 and the second layer 220. Therefore, according to the current collector 10, the mass percent concentration of the metal filler can be changed between the first layer 210 and the second layer 220. As a result, according to the current collector 10, the mass percent concentration of the metal filler can be appropriately adjusted for each layer.
  • the second conductive resin layer 200 includes the first layer 210 and the second layer 220.
  • the second conductive resin layer 200 does not necessarily have to include the first layer 210 and the second layer 220.
  • the second conductive resin layer 200 may be composed of one layer.
  • FIG. 3 is a diagram showing a cross section of the current collector 10A in the modified example.
  • the current collector 10A includes a first conductive resin layer 100 and a second conductive resin layer 200A.
  • the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10A.
  • the second conductive resin layer 200A is composed of one layer.
  • the second conductive resin layer 200A contains a polyolefin and a conductive filler as in the case of the second conductive resin layer 200 in the above embodiment. Such a configuration may be adopted.
  • the current collector 10 is manufactured by coextrusion molding.
  • the method for manufacturing the current collector 10 is not limited to this.
  • the current collector 10 may be manufactured by a laminating and casting method.
  • no metal coating layer is particularly formed above the second conductive resin layer 200 and below the first conductive resin layer 100.
  • the metal coating layer may be formed on both or one of the upper side of the second conductive resin layer 200 and the lower side of the first conductive resin layer 100.
  • Metal species used for the coating layer include nickel, copper, silver and aluminum. Alternatively, those alloys may be used.
  • examples of the coating method include a vapor deposition method, a sputtering method, a plating method, and a coating method.
  • At least one metal selected from the group containing platinum, gold, silver, copper, SUS, nickel and titanium may be mixed in the first conductive resin layer 100, and the second conductive resin layer 200 may be mixed. May be mixed with conductive carbon.
  • the thickness of the current collector of Comparative Example 1 was 49.0 ⁇ m.
  • the ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 40%.
  • Nickel (Ni) was used as the conductive filler for the first layer and the second layer.
  • the mass percent concentration of nickel in the second layer was 60 wt%.
  • the mass percent concentration of nickel in the first layer was 70 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer.
  • the mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
  • Example 1 The thickness of the current collector of Example 1 was 54.2 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%.
  • Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
  • Example 2 The thickness of the current collector of Example 2 was 53.0 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 67%.
  • Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
  • Example 3 The thickness of the current collector of Example 3 was 47.6 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 75%.
  • Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
  • Example 4 The thickness of the current collector of Example 4 was 52.6 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%.
  • Nickel (Ni) was used as the conductive filler of the second conductive resin layer. The mass percent concentration of nickel in the second conductive resin layer was 71 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 30 wt%.
  • Example 5 The thickness of the current collector of Example 5 was 52.4 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%.
  • Nickel (Ni) was used as the conductive filler of the second conductive resin layer. The mass percent concentration of nickel in the second conductive resin layer was 72 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 30 wt%.
  • Example 6 The thickness of the current collector of Example 6 was 53.8 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%.
  • Nickel (Ni) was used as the conductive filler of the second conductive resin layer. The mass percent concentration of nickel in the second conductive resin layer was 73 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 30 wt%.
  • Example 7 The thickness of the current collector of Example 7 was 56.6 ⁇ m. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%.
  • Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 80 wt%. The mass percent concentration of nickel in the first layer was 70 wt%.
  • Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 32 wt%.
  • a sample whose penetration resistance value was measured before pressing was sandwiched between smooth SUS plates having a size of 100 mm square and a thickness of 1.5 mm, and pressed at a pressure of 16.5 kN for 10 seconds [SA-401 Tester Sangyo Co., Ltd.] Made].
  • the method of measuring the penetration resistance value before and after pressing is as follows. A 7 cm square sample is cut and taken out from each collector, and the thickness direction (penetration direction) of the collector is used with an electric resistance measuring instrument [IMC-0240 type manufactured by Imoto Seisakusho Co., Ltd.] and a resistance meter [RM3548 HIOKI manufactured]. ) was measured. The resistance value of the current collector was measured with a load of 2.16 kg applied to the electric resistance measuring instrument, and the value 60 seconds after the load was applied was taken as the resistance value of the current collector.
  • the value obtained by multiplying the resistance value by the area of the contact surface of the jig at the time of resistance measurement (3.14 cm 2 ) was defined as the penetration resistance value ( ⁇ ⁇ cm 2 ).
  • Penetration resistance value ( ⁇ ⁇ cm 2 ) resistance value ( ⁇ ) ⁇ 3.14 (cm 2 ) ⁇ ⁇ ⁇ (1)
  • the method for measuring the penetration resistance value is also common to other tests.
  • the current collector was allowed to stand in a room temperature environment for 2 minutes, and then the penetration resistance value of the current collector was measured. This measurement result was used as the resistance value at room temperature.
  • FIG. 4 is a diagram showing the shape of the test piece of the current collector 10 used for measuring the tear strength.
  • the tear strength the right-angled tear strength was measured.
  • the test piece cut out as shown in FIG. 4 was accurately attached to the tensile tester by aligning the axial direction of the test piece with the gripping tool direction of the tester.
  • an autograph Shiadzu precision universal testing machine Autograph AG-X 500N was used. The test speed was 200 mm / min, and the strength at the time of cutting the test piece was measured.
  • the rate of increase (change ratio) of the penetration resistance value of the current collector before and after pressing was suppressed in each of Examples 1-3 as compared with Comparative Example 1. That is, when the thickness of the first conductive resin layer is 50% or more with respect to the thickness of the current collector, the rate of increase (change ratio) of the penetration resistance value of the current collector before and after pressing is suppressed. I was able to confirm.
  • Table 3 summarizes the changes in resistance value before and after pressing for Examples 1 and 4-7.
  • Table 4 summarizes the changes in the resistance value of the current collector for each temperature with respect to Comparative Example 1 and Example 1-3.
  • Table 5 summarizes how the resistance values of the current collectors of Comparative Example 1 and Example 1-3 change for each temperature when the data at room temperature is 1.00. ..
  • 10 current collector 100 first conductive resin layer, 200 second conductive resin layer, 210 first layer, 220 second layer, 500 manufacturing equipment, 510 T-die, 520, 530, 540 raw material input section.

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  • Engineering & Computer Science (AREA)
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  • Cell Electrode Carriers And Collectors (AREA)

Abstract

This current collector comprises a first electroconductive resin layer and a second electroconductive resin layer. The first electroconductive resin layer contains a first electroconductive filler. The second electroconductive resin layer is formed on the first electroconductive resin layer and contains a second electroconductive filler. The first electroconductive filler is an electroconductive carbon. The second electroconductive filler contains at least one metal selected from the group consisting of platinum, gold, silver, copper, stainless used steel (SUS), nickel, and titanium. The thickness of the first electroconductive resin layer is at least 50% of the thickness of the current collector.

Description

集電体Current collector
 本発明は、集電体に関し、特に、リチウムイオン電池用の集電体に関する。 The present invention relates to a current collector, and more particularly to a current collector for a lithium ion battery.
 特開2018-55967号公報(特許文献1)は、第1導電性フィラーを含む第1導電性樹脂層と、第2導電性フィラーを含む第2導電性樹脂層とを備えるリチウムイオン電池用の集電体を開示する。このリチウムイオン電池用の集電体において、第1導電性フィラーは、導電性カーボンであり、第2導電性フィラーは、白金、金、銀、銅、ニッケル及びチタンが含まれる群から選択される少なくとも1種類の金属元素を含む。第1導電性フィラーとして導電性カーボンを用いることによって、第1導電性フィラーとして金属元素を用いる場合と比較して、集電体の軽量化を実現することができる(特許文献1参照)。 Japanese Patent Application Laid-Open No. 2018-55967 (Patent Document 1) is for a lithium ion battery including a first conductive resin layer containing a first conductive filler and a second conductive resin layer containing a second conductive filler. Disclose the current collector. In the current collector for the lithium ion battery, the first conductive filler is conductive carbon and the second conductive filler is selected from the group containing platinum, gold, silver, copper, nickel and titanium. Contains at least one metal element. By using the conductive carbon as the first conductive filler, the weight of the current collector can be reduced as compared with the case where the metal element is used as the first conductive filler (see Patent Document 1).
特開2018-55967号公報Japanese Unexamined Patent Publication No. 2018-55967
 上記特許文献1に開示されているような集電体を用いたリチウムイオン電池の製造過程において、集電体にプレス加工が施される場合がある。上記特許文献1に開示されているような集電体にプレス加工を施すと、集電体の貫通抵抗値が上昇することを本発明者(ら)は見出した。 In the process of manufacturing a lithium ion battery using a current collector as disclosed in Patent Document 1, the current collector may be pressed. The present inventors have found that when a current collector as disclosed in Patent Document 1 is pressed, the penetration resistance value of the current collector increases.
 本発明は、このような問題を解決するためになされたものであって、その目的は、プレス加工に起因する貫通抵抗値の上昇を抑制可能な集電体を提供することである。 The present invention has been made to solve such a problem, and an object of the present invention is to provide a current collector capable of suppressing an increase in penetration resistance value due to press working.
 本発明に従う集電体は、リチウムイオン電池用の集電体である。この集電体は、第1導電性樹脂層と、第2導電性樹脂層とを備える。第1導電性樹脂層は、第1導電性フィラーを含む。第2導電性樹脂層は、第1導電性樹脂層上に形成されており、第2導電性フィラーを含む。第1導電性フィラーは、導電性カーボンである。第2導電性フィラーは、白金、金、銀、銅、SUS(Stainless Used Steel)、ニッケル及びチタンが含まれる群から選択される少なくとも1種類の金属を含む。第1導電性樹脂層の厚みは、集電体の厚みの50%以上である。 The current collector according to the present invention is a current collector for a lithium ion battery. This current collector includes a first conductive resin layer and a second conductive resin layer. The first conductive resin layer contains the first conductive filler. The second conductive resin layer is formed on the first conductive resin layer and contains the second conductive filler. The first conductive filler is conductive carbon. The second conductive filler contains at least one metal selected from the group containing platinum, gold, silver, copper, SUS (Stainless Used Steel), nickel and titanium. The thickness of the first conductive resin layer is 50% or more of the thickness of the current collector.
 本発明者(ら)は、第1導電性樹脂層の厚みを厚くすることによって、プレス加工に起因する集電体の貫通抵抗値の上昇を抑制可能であることを見出した。本発明に従う集電体においては、第1導電性樹脂層の厚みが、集電体の厚みの50%以上である。したがって、この集電体によれば、第1導電性樹脂層の厚みが比較的厚いため、プレス加工に起因する集電体の貫通抵抗値の上昇を抑制することができる。 The present inventors have found that by increasing the thickness of the first conductive resin layer, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working. In the current collector according to the present invention, the thickness of the first conductive resin layer is 50% or more of the thickness of the current collector. Therefore, according to this current collector, since the thickness of the first conductive resin layer is relatively thick, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
 上記集電体において、第1導電性樹脂層の厚みは、集電体の厚みの67%以上であってもよい。 In the current collector, the thickness of the first conductive resin layer may be 67% or more of the thickness of the current collector.
 上記集電体において、第1導電性樹脂層の厚みは、集電体の厚みの75%以上であってもよい。 In the current collector, the thickness of the first conductive resin layer may be 75% or more of the thickness of the current collector.
 上記集電体において、第2導電性樹脂層は、第1導電性樹脂層に近い第1層と、第1導電性樹脂層から遠い第2層とを含んでもよい。 In the current collector, the second conductive resin layer may include a first layer close to the first conductive resin layer and a second layer far from the first conductive resin layer.
 この集電体においては、第2導電性樹脂層が第1層と第2層とを含んでいる。したがって、この集電体によれば、第1層と第2層とで金属の質量パーセント濃度を変更することができる。その結果、この集電体によれば、金属の質量パーセント濃度を層毎に適切に調節することができる。 In this current collector, the second conductive resin layer includes the first layer and the second layer. Therefore, according to this current collector, the mass percent concentration of the metal can be changed between the first layer and the second layer. As a result, according to this current collector, the mass percent concentration of the metal can be appropriately adjusted for each layer.
 上記集電体において、第2導電性フィラーはニッケルを含んでもよい。 In the current collector, the second conductive filler may contain nickel.
 上記集電体において、第2層における金属の質量パーセント濃度は、第1層における金属の質量パーセント濃度よりも高くてもよい。 In the current collector, the mass percent concentration of the metal in the second layer may be higher than the mass percent concentration of the metal in the first layer.
 本発明者(ら)は、第2層における金属の質量パーセント濃度を高くする程、プレス加工に起因する集電体の貫通抵抗値の上昇を抑制可能であることを見出した。本発明に従う集電体においては、第2層における金属の質量パーセント濃度が、第1層における金属の質量パーセント濃度よりも高い。したがって、この集電体によれば、第2層における金属の質量パーセント濃度が比較的高いため、プレス加工に起因する集電体の貫通抵抗値の上昇を抑制することができる。 The present inventors have found that the higher the mass percent concentration of the metal in the second layer, the more it is possible to suppress the increase in the penetration resistance value of the current collector due to press working. In the current collector according to the present invention, the mass percent concentration of the metal in the second layer is higher than the mass percent concentration of the metal in the first layer. Therefore, according to this current collector, since the mass percent concentration of the metal in the second layer is relatively high, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
 本発明によれば、プレス加工に起因する貫通抵抗値の上昇を抑制可能な集電体を提供することができる。 According to the present invention, it is possible to provide a current collector capable of suppressing an increase in penetration resistance value due to press working.
集電体の断面を示す図である。It is a figure which shows the cross section of a current collector. 集電体の製造装置を模式的に示す図である。It is a figure which shows typically the manufacturing apparatus of a current collector. 変形例における、集電体の断面を示す図である。It is a figure which shows the cross section of the current collector in the modification. 引裂き強度の測定に用いられた試験片の形状を示す図である。It is a figure which shows the shape of the test piece used for measuring the tear strength. カールに関し評価が「A」の例を示す図である。It is a figure which shows the example of the evaluation of "A" with respect to a curl. カールに関し評価が「B」の例を示す図である。It is a figure which shows the example of the evaluation of "B" with respect to a curl. カールに関し評価が「C」の例を示す図である。It is a figure which shows the example of the evaluation of "C" with respect to a curl. カールに関し評価が「D」の例を示す図である。It is a figure which shows the example of the evaluation of "D" with respect to a curl.
 以下、本発明の実施の形態について、図面を参照しながら詳細に説明する。なお、図中同一又は相当部分には同一符号を付してその説明は繰り返さない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.
 [1.集電体の構成]
 図1は、本実施の形態に従う集電体10の断面を示す図である。集電体10は、例えば、リチウムイオン電池の負極用集電体に用いられる。図1に示されるように、集電体10は、第1導電性樹脂層100と、第2導電性樹脂層200とを含んでいる。
[1. Current collector configuration]
FIG. 1 is a diagram showing a cross section of a current collector 10 according to the present embodiment. The current collector 10 is used, for example, as a current collector for the negative electrode of a lithium ion battery. As shown in FIG. 1, the current collector 10 includes a first conductive resin layer 100 and a second conductive resin layer 200.
 リチウムイオン電池においては、第2導電性樹脂層200の上方に負極用の活物質が塗布され、第1導電性樹脂層100の下方に正極用集電体が配置される。リチウムイオン電池の製造過程においては、集電体10上に負極用の活物質が塗布された状態で、集電体10にプレス加工が施される。リチウムイオン電池においては、集電体10の貫通方向(図中上下方向)に電流が流れる。なお、第1導電性樹脂層100の厚さ(T1)は、集電体10の厚さ(T2)の50%以上、90%以下である。好ましくは、第1導電性樹脂層100の厚さ(T1)は集電体10の厚さ(T2)の67%以上であり、より好ましくは、第1導電性樹脂層100の厚さは集電体10の厚さの75%以上である。以下、各層について説明する。 In the lithium ion battery, the active material for the negative electrode is applied above the second conductive resin layer 200, and the current collector for the positive electrode is arranged below the first conductive resin layer 100. In the manufacturing process of the lithium ion battery, the current collector 10 is pressed with the active material for the negative electrode coated on the current collector 10. In the lithium ion battery, a current flows in the penetrating direction (vertical direction in the figure) of the current collector 10. The thickness (T1) of the first conductive resin layer 100 is 50% or more and 90% or less of the thickness (T2) of the current collector 10. Preferably, the thickness (T1) of the first conductive resin layer 100 is 67% or more of the thickness (T2) of the current collector 10, and more preferably, the thickness of the first conductive resin layer 100 is collected. It is 75% or more of the thickness of the electric body 10. Hereinafter, each layer will be described.
 <1-1.第1導電性樹脂層>
 第1導電性樹脂層100は、ポリオレフィンと、導電性フィラーとを含んでいる。すなわち、第1導電性樹脂層100は、ポリオレフィンと導電性フィラーとを混合することによって形成されている。
<1-1. First conductive resin layer>
The first conductive resin layer 100 contains a polyolefin and a conductive filler. That is, the first conductive resin layer 100 is formed by mixing polyolefin and a conductive filler.
 ポリオレフィンとしては、例えば、ポリプロピレン(PP)及びポリエチレン(PE)が挙げられる。また、炭素数4~30のα-オレフィン(1-ブテン、イソブテン、1-ヘキセン、1-デセン又は1-ドデセン等)を必須構成単量体とする重合体等がポリオレフィンとして用いられてもよい。これらのポリオレフィンは、1種単独であってもよいし、2種以上の混合物であってもよい。 Examples of the polyolefin include polypropylene (PP) and polyethylene (PE). Further, a polymer or the like containing an α-olefin having 4 to 30 carbon atoms (1-butene, isobutene, 1-hexene, 1-decene, 1-dodecene, etc.) as an essential constituent monomer may be used as the polyolefin. .. These polyolefins may be one kind alone or a mixture of two or more kinds.
 ポリオレフィンの中でも、防湿特性及び機械的強度の観点で、ポリプロピレンが好ましい。ポリプロピレンとしては、例えば、ホモポリプロピレン、ランダムポリプロピレン、ブロックポリプロピレン、長鎖分岐構造を有するポリプロピレン及び酸変性ポリプロピレンが挙げられる。 Among polyolefins, polypropylene is preferable from the viewpoint of moisture-proof properties and mechanical strength. Examples of polypropylene include homopolypropylene, random polypropylene, block polypropylene, polypropylene having a long-chain branched structure, and acid-modified polypropylene.
 ホモポリプロピレンは、プロピレンの単独重合体である。ランダムポリプロピレンは、不規則に導入された少量(好ましくは、4.5重量%以下)のエチレン単位を含む共重合体である。ブロックポリプロピレンは、ホモポリプロピレンの中にエチレンプロピレンゴム(EPR)が分散している組成物であり、ホモポリプロピレンの「海」の中にEPRを含む「島」が浮かぶ「海島構造」を有している。酸変性ポリプロピレンは、無水マレイン酸等の不飽和カルボン酸とポリプロピレンとを有機過酸化物の存在下で反応させる等の公知の方法を通じて得ることができる。 Homopolypropylene is a homopolymer of propylene. Random polypropylene is a copolymer containing a small amount (preferably 4.5% by weight or less) of ethylene units introduced irregularly. Block polypropylene is a composition in which ethylene propylene rubber (EPR) is dispersed in homopolypropylene, and has a "sea island structure" in which "islands" containing EPR float in the "sea" of homopolypropylene. There is. The acid-modified polypropylene can be obtained through a known method such as reacting an unsaturated carboxylic acid such as maleic anhydride with polypropylene in the presence of an organic peroxide.
 第1導電性樹脂層100に含まれる導電性フィラーとしては、導電性カーボンが挙げられる。導電性カーボンとしては、例えば、黒鉛(グラファイト)、カーボンブラック(アセチレンブラック、ケッチェンブラック、ファーネスブラック、チャンネルブラック、サーマルランプブラック等)、カーボンナノチューブ及びこれらの混合物が挙げられる。 Examples of the conductive filler contained in the first conductive resin layer 100 include conductive carbon. Examples of the conductive carbon include graphite, carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), carbon nanotubes, and mixtures thereof.
 導電性カーボンの中では、カーボンブラックが好ましく、アセチレンブラック、ファーネスブラック、又は、それらの混合物がより好ましい。カーボンブラックの体積平均粒子径は、特に限定されないが、集電体10が用いられるリチウムイオン電池の電気特性の観点から、3~500nmであることが好ましい。 Among the conductive carbons, carbon black is preferable, and acetylene black, furnace black, or a mixture thereof is more preferable. The volume average particle size of carbon black is not particularly limited, but is preferably 3 to 500 nm from the viewpoint of the electrical characteristics of the lithium ion battery in which the current collector 10 is used.
 <1-2.第2導電性樹脂層>
 第2導電性樹脂層200は、第1導電性樹脂層100上に形成されており、第1層210と、第2層220とを含んでいる。第1層210及び第2層220の各々は、ポリオレフィンと、導電性フィラーとを含んでいる。すなわち、第1層210及び第2層220の各々は、ポリオレフィンと導電性フィラーとを混合することによって形成されている。ポリオレフィンとしては、例えば、第1導電性樹脂層100の説明において例示したものを用いることができる。
<1-2. Second conductive resin layer>
The second conductive resin layer 200 is formed on the first conductive resin layer 100, and includes the first layer 210 and the second layer 220. Each of the first layer 210 and the second layer 220 contains a polyolefin and a conductive filler. That is, each of the first layer 210 and the second layer 220 is formed by mixing polyolefin and a conductive filler. As the polyolefin, for example, those exemplified in the description of the first conductive resin layer 100 can be used.
 第2導電性樹脂層200に含まれる導電性フィラーとしては、白金、金、銀、銅、SUS(Stainless Used Steel)、ニッケル、チタン及びこれらの混合物が挙げられる。すなわち、第2導電性樹脂層200に含まれる導電性フィラーは、白金、金、銀、銅、SUS、ニッケル及びチタンが含まれる群から選択される少なくとも1種類の金属を含む。なお、これらの中では、ニッケル粒子が導電性フィラーとしてより好ましい。 Examples of the conductive filler contained in the second conductive resin layer 200 include platinum, gold, silver, copper, SUS (Stainless Used Steel), nickel, titanium and a mixture thereof. That is, the conductive filler contained in the second conductive resin layer 200 contains at least one metal selected from the group containing platinum, gold, silver, copper, SUS, nickel and titanium. Among these, nickel particles are more preferable as the conductive filler.
 第2導電性樹脂層200においては、第1層210における導電性フィラー(金属元素)の質量パーセント濃度が70wt%以上である。したがって、集電体10においては、第1導電性樹脂層100の温度が上昇し該温度上昇に伴なって第1層210が膨張したとしても、第1層210の導電性フィラーの質量パーセント濃度が高いため、導電性フィラー同士の接触が維持され易い。したがって、集電体10によれば、第1導電性樹脂層100の温度上昇に伴なう第2導電性樹脂層200の抵抗値の上昇を抑制することができる。 In the second conductive resin layer 200, the mass percent concentration of the conductive filler (metal element) in the first layer 210 is 70 wt% or more. Therefore, in the current collector 10, even if the temperature of the first conductive resin layer 100 rises and the first layer 210 expands with the temperature rise, the mass percent concentration of the conductive filler of the first layer 210 Therefore, the contact between the conductive fillers is easily maintained. Therefore, according to the current collector 10, it is possible to suppress an increase in the resistance value of the second conductive resin layer 200 with an increase in the temperature of the first conductive resin layer 100.
 また、第2層220における導電性フィラー(金属)の質量パーセント濃度は60wt%以上である。第2層220における導電性フィラーの質量パーセント濃度がある程度高いため、集電体10にプレス加工が施されても第2層220における導電性フィラー間の導電経路が切断されにくい。その結果、集電体10によれば、プレス加工に起因する貫通抵抗値の上昇を抑制することができる。 Further, the mass percent concentration of the conductive filler (metal) in the second layer 220 is 60 wt% or more. Since the mass percent concentration of the conductive filler in the second layer 220 is high to some extent, it is difficult to cut the conductive path between the conductive fillers in the second layer 220 even if the current collector 10 is pressed. As a result, according to the current collector 10, it is possible to suppress an increase in the penetration resistance value due to press working.
 なお、第2層220における導電性フィラーの質量パーセント濃度は、第1層210における導電性フィラーの質量パーセント濃度よりも高くてもよい。この集電体10によれば、第2層220における導電性フィラーの質量パーセント濃度が比較的高いため、プレス加工に起因する集電体10の貫通抵抗値の上昇を抑制することができる。 The mass percent concentration of the conductive filler in the second layer 220 may be higher than the mass percent concentration of the conductive filler in the first layer 210. According to the current collector 10, since the mass percent concentration of the conductive filler in the second layer 220 is relatively high, it is possible to suppress an increase in the penetration resistance value of the current collector 10 due to press working.
 [2.第1導電性樹脂層が厚い理由]
 上述のように、集電体10においては、第1導電性樹脂層100の厚さ(T1)が、集電体10の厚さ(T2)の50%以上である。このように、集電体10においては、第1導電性樹脂層100の厚さが比較的厚い。以下、第1導電性樹脂層100が厚い理由について説明する。
[2. Reason why the first conductive resin layer is thick]
As described above, in the current collector 10, the thickness (T1) of the first conductive resin layer 100 is 50% or more of the thickness (T2) of the current collector 10. As described above, in the current collector 10, the thickness of the first conductive resin layer 100 is relatively thick. Hereinafter, the reason why the first conductive resin layer 100 is thick will be described.
 リチウムイオン電池の製造過程において、集電体にプレス加工が施される場合がある。集電体の構成によっては、集電体にプレス加工が施されると、集電体の貫通抵抗値が上昇することに本発明者(ら)は気付いた。 In the manufacturing process of lithium-ion batteries, the current collector may be pressed. The present inventors have noticed that, depending on the configuration of the current collector, the penetration resistance value of the current collector increases when the current collector is pressed.
 本発明者(ら)は、第1導電性樹脂層100の厚みを厚くすることによって、プレス加工に起因する集電体の貫通抵抗値の上昇を抑制可能であることを見出した。集電体10においては、第1導電性樹脂層100の厚みが、集電体10の厚みの50%以上である。したがって、集電体10によれば、第1導電性樹脂層100の厚みが比較的厚いため、プレス加工に起因する集電体の貫通抵抗値の上昇を抑制することができる。 The present inventors have found that by increasing the thickness of the first conductive resin layer 100, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working. In the current collector 10, the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10. Therefore, according to the current collector 10, since the thickness of the first conductive resin layer 100 is relatively thick, it is possible to suppress an increase in the penetration resistance value of the current collector due to press working.
 また、本発明者(ら)は、第1導電性樹脂層100の厚みを厚くすることによる他のメリットも見出した。一般的に、リチウムイオン電池の使用中に集電体の温度は上昇する。集電体の温度が上昇すると、集電体の貫通抵抗値も上昇する。本発明者(ら)は、第1導電性樹脂層100の厚みを厚くすることによって、集電体10の温度上昇に伴なう集電体10の貫通抵抗値の上昇が抑制されることを見出した。また、本発明者(ら)は、第1導電性樹脂層100の厚みを厚くすることによって、集電体10の引裂強度が高まることを見出した。これらについては、後述の実施例を通じて後程詳細に説明する。これらの観点から、集電体10においては、第1導電性樹脂層100の厚みが集電体10の厚みの50%以上になっている。また、本発明者(ら)は、第1導電性樹脂層100の厚みを厚くすることによって、第1導電性樹脂層100が内側に巻かれるような集電体10のカールが抑制されることを見出した。 The present inventors have also found other merits by increasing the thickness of the first conductive resin layer 100. Generally, the temperature of the current collector rises during the use of the lithium-ion battery. As the temperature of the current collector rises, the penetration resistance value of the current collector also rises. The present inventors have found that by increasing the thickness of the first conductive resin layer 100, an increase in the penetration resistance value of the current collector 10 accompanying an increase in the temperature of the current collector 10 is suppressed. I found it. Further, the present inventors have found that the tear strength of the current collector 10 is increased by increasing the thickness of the first conductive resin layer 100. These will be described in detail later through Examples described later. From these viewpoints, in the current collector 10, the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10. Further, the present inventor (or others) suppresses curling of the current collector 10 such that the first conductive resin layer 100 is wound inward by increasing the thickness of the first conductive resin layer 100. I found.
 [3.集電体の製造方法]
 図2は、集電体10の製造装置500を模式的に示す図である。図2に示されるように、製造装置500は、Tダイ部510と、原料投入部520,530,540とを含んでいる。
[3. Current collector manufacturing method]
FIG. 2 is a diagram schematically showing the manufacturing apparatus 500 of the current collector 10. As shown in FIG. 2, the manufacturing apparatus 500 includes a T-die unit 510 and a raw material input unit 520, 530, 540.
 原料投入部520には、第2導電性樹脂層200の第2層220を形成するための導電性樹脂原料が投入される。原料投入部530には、第2導電性樹脂層200の第1層210を形成するための導電性樹脂原料が投入される。原料投入部540には、第1導電性樹脂層100を形成するための導電性樹脂原料が投入される。 A conductive resin raw material for forming the second layer 220 of the second conductive resin layer 200 is charged into the raw material charging section 520. A conductive resin raw material for forming the first layer 210 of the second conductive resin layer 200 is charged into the raw material charging section 530. A conductive resin raw material for forming the first conductive resin layer 100 is charged into the raw material charging section 540.
 Tダイ部510は、原料投入部520,530,540を介して投入された原料を共押出しすることによって、導電性樹脂原料の溶融物同士を融着させて1枚の一体化したフィルムとするように構成されている。すなわち、Tダイ部510は、原料投入部520,530,540を介して投入された原料に基づいて、フィルム状の集電体10を生成するように構成されている。このように、集電体10は、例えば、製造装置500によって、第1導電性樹脂層100、第1層210及び第2層220が積層されることによって製造される。 The T-die portion 510 coextrudes the raw materials charged through the raw material charging parts 520, 530, and 540 to fuse the melts of the conductive resin raw materials into one integrated film. It is configured as follows. That is, the T-die unit 510 is configured to generate a film-shaped current collector 10 based on the raw material input via the raw material input units 520, 530, and 540. As described above, the current collector 10 is manufactured, for example, by laminating the first conductive resin layer 100, the first layer 210, and the second layer 220 by the manufacturing apparatus 500.
 [4.特徴]
 以上のように、本実施の形態に従う集電体10においては、第1導電性樹脂層100の厚みが、集電体10の厚みの50%以上である。したがって、集電体10によれば、第1導電性樹脂層100の厚みが比較的厚いため、プレス加工に起因する集電体10の貫通抵抗値の上昇を抑制することができる。
[4. feature]
As described above, in the current collector 10 according to the present embodiment, the thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10. Therefore, according to the current collector 10, since the thickness of the first conductive resin layer 100 is relatively thick, it is possible to suppress an increase in the penetration resistance value of the current collector 10 due to press working.
 また、集電体10においては、第2導電性樹脂層200が第1層210と第2層220とを含んでいる。したがって、集電体10によれば、第1層210と第2層220とで金属フィラーの質量パーセント濃度を変更することができる。その結果、集電体10によれば、金属フィラーの質量パーセント濃度を層毎に適切に調節することができる。 Further, in the current collector 10, the second conductive resin layer 200 includes the first layer 210 and the second layer 220. Therefore, according to the current collector 10, the mass percent concentration of the metal filler can be changed between the first layer 210 and the second layer 220. As a result, according to the current collector 10, the mass percent concentration of the metal filler can be appropriately adjusted for each layer.
 [5.変形例]
 以上、実施の形態について説明したが、本発明は、上記実施の形態に限定されるものではなく、その趣旨を逸脱しない限りにおいて、種々の変更が可能である。以下、変形例について説明する。
[5. Modification example]
Although the embodiments have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. Hereinafter, a modified example will be described.
 上記実施の形態においては、第2導電性樹脂層200が第1層210と第2層220とを含んでいた。しかしながら、第2導電性樹脂層200は、必ずしも第1層210と第2層220とを含んでいなくてもよい。例えば、第2導電性樹脂層200は、一層で構成されていてもよい。 In the above embodiment, the second conductive resin layer 200 includes the first layer 210 and the second layer 220. However, the second conductive resin layer 200 does not necessarily have to include the first layer 210 and the second layer 220. For example, the second conductive resin layer 200 may be composed of one layer.
 図3は、変形例における、集電体10Aの断面を示す図である。図3に示されるように集電体10Aは、第1導電性樹脂層100と、第2導電性樹脂層200Aとを含んでいる。第1導電性樹脂層100の厚みは、集電体10Aの厚みの50%以上である。第2導電性樹脂層200Aは、一層で構成されている。第2導電性樹脂層200Aは、上記実施の形態における第2導電性樹脂層200と同様、ポリオレフィンと、導電性フィラーとを含んでいる。このような構成が採用されてもよい。 FIG. 3 is a diagram showing a cross section of the current collector 10A in the modified example. As shown in FIG. 3, the current collector 10A includes a first conductive resin layer 100 and a second conductive resin layer 200A. The thickness of the first conductive resin layer 100 is 50% or more of the thickness of the current collector 10A. The second conductive resin layer 200A is composed of one layer. The second conductive resin layer 200A contains a polyolefin and a conductive filler as in the case of the second conductive resin layer 200 in the above embodiment. Such a configuration may be adopted.
 また、上記実施の形態において、集電体10は、共押出成形で製造された。しかしながら、集電体10の製造方法はこれに限定されない。例えば、集電体10は、張り合わせ及びキャスト法で製造されてもよい。 Further, in the above embodiment, the current collector 10 is manufactured by coextrusion molding. However, the method for manufacturing the current collector 10 is not limited to this. For example, the current collector 10 may be manufactured by a laminating and casting method.
 また、上記実施の形態においては、第2導電性樹脂層200の上方及び第1導電性樹脂層100の下方に特に金属被膜層が形成されていなかった。しかしながら、第2導電性樹脂層200の上方及び第1導電性樹脂層100の下方の両方又は一方に金属被膜層が形成されてもよい。被覆層に使用される金属種としては、ニッケル、銅、銀、アルミニウムが挙げられる。または、それらの合金でもよい。また、被覆方法としては、蒸着法、スパッタ法、メッキ法、コーティングが挙げられる。 Further, in the above embodiment, no metal coating layer is particularly formed above the second conductive resin layer 200 and below the first conductive resin layer 100. However, the metal coating layer may be formed on both or one of the upper side of the second conductive resin layer 200 and the lower side of the first conductive resin layer 100. Metal species used for the coating layer include nickel, copper, silver and aluminum. Alternatively, those alloys may be used. Further, examples of the coating method include a vapor deposition method, a sputtering method, a plating method, and a coating method.
 また、第1導電性樹脂層100に白金、金、銀、銅、SUS、ニッケル及びチタンが含まれる群から選択される少なくとも1種類の金属が混合されてもよく、第2導電性樹脂層200に導電性カーボンが混合されてもよい。 Further, at least one metal selected from the group containing platinum, gold, silver, copper, SUS, nickel and titanium may be mixed in the first conductive resin layer 100, and the second conductive resin layer 200 may be mixed. May be mixed with conductive carbon.
 [6.実施例等]
 <6-1.実施例及び比較例>
 実施例1-7及び比較例1の集電体を準備した。実施例1-3,7及び比較例1の各々の集電体は、図1に示されるような3層構成であった。実施例4-6の各々の集電体は、図3に示されるような2層構成であった。いずれの例においても、各層はポリプロピレン樹脂を含んでいた。
[6. Examples, etc.]
<6-1. Examples and Comparative Examples>
The current collectors of Examples 1-7 and Comparative Example 1 were prepared. Each of the current collectors of Examples 1-3 and 7 and Comparative Example 1 had a three-layer structure as shown in FIG. Each current collector of Example 4-6 had a two-layer structure as shown in FIG. In each example, each layer contained polypropylene resin.
 (6-1-1.比較例1)
 比較例1の集電体の厚みは、49.0μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は40%であった。第1層及び第2層の導電性フィラーとしてはニッケル(Ni)を用いた。第2層におけるニッケルの質量パーセント濃度は、60wt%であった。第1層におけるニッケルの質量パーセント濃度は、70wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、26wt%であった。
(6-1-1. Comparative Example 1)
The thickness of the current collector of Comparative Example 1 was 49.0 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 40%. Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
 (6-1-2.実施例1)
 実施例1の集電体の厚みは、54.2μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は50%であった。第1層及び第2層の導電性フィラーとしてはニッケル(Ni)を用いた。第2層におけるニッケルの質量パーセント濃度は、60wt%であった。第1層におけるニッケルの質量パーセント濃度は、70wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、26wt%であった。
(6-1-2. Example 1)
The thickness of the current collector of Example 1 was 54.2 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%. Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
 (6-1-3.実施例2)
 実施例2の集電体の厚みは、53.0μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は67%であった。第1層及び第2層の導電性フィラーとしてはニッケル(Ni)を用いた。第2層におけるニッケルの質量パーセント濃度は、60wt%であった。第1層におけるニッケルの質量パーセント濃度は、70wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、26wt%であった。
(6-1-3. Example 2)
The thickness of the current collector of Example 2 was 53.0 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 67%. Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
 (6-1-4.実施例3)
 実施例3の集電体の厚みは、47.6μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は75%であった。第1層及び第2層の導電性フィラーとしてはニッケル(Ni)を用いた。第2層におけるニッケルの質量パーセント濃度は、60wt%であった。第1層におけるニッケルの質量パーセント濃度は、70wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、26wt%であった。
(6-1-4. Example 3)
The thickness of the current collector of Example 3 was 47.6 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 75%. Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 60 wt%. The mass percent concentration of nickel in the first layer was 70 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 26 wt%.
 (6-1-5.実施例4)
 実施例4の集電体の厚みは、52.6μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は50%であった。第2導電性樹脂層の導電性フィラーとしてはニッケル(Ni)を用いた。第2導電性樹脂層におけるニッケルの質量パーセント濃度は、71wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、30wt%であった。
(6-1-5. Example 4)
The thickness of the current collector of Example 4 was 52.6 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%. Nickel (Ni) was used as the conductive filler of the second conductive resin layer. The mass percent concentration of nickel in the second conductive resin layer was 71 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 30 wt%.
 (6-1-6.実施例5)
 実施例5の集電体の厚みは、52.4μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は50%であった。第2導電性樹脂層の導電性フィラーとしてはニッケル(Ni)を用いた。第2導電性樹脂層におけるニッケルの質量パーセント濃度は、72wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、30wt%であった。
(6-1-6. Example 5)
The thickness of the current collector of Example 5 was 52.4 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%. Nickel (Ni) was used as the conductive filler of the second conductive resin layer. The mass percent concentration of nickel in the second conductive resin layer was 72 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 30 wt%.
 (6-1-7.実施例6)
 実施例6の集電体の厚みは、53.8μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は50%であった。第2導電性樹脂層の導電性フィラーとしてはニッケル(Ni)を用いた。第2導電性樹脂層におけるニッケルの質量パーセント濃度は、73wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、30wt%であった。
(6-1-7. Example 6)
The thickness of the current collector of Example 6 was 53.8 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%. Nickel (Ni) was used as the conductive filler of the second conductive resin layer. The mass percent concentration of nickel in the second conductive resin layer was 73 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 30 wt%.
 (6-1-8.実施例7)
 実施例7の集電体の厚みは、56.6μmであった。集電体の厚みに対する第1導電性樹脂層の厚みの割合は50%であった。第1層及び第2層の導電性フィラーとしてはニッケル(Ni)を用いた。第2層におけるニッケルの質量パーセント濃度は、80wt%であった。第1層におけるニッケルの質量パーセント濃度は、70wt%であった。第1導電性樹脂層の導電性フィラーとしてはファーネスブラックを用いた。第1導電性樹脂層におけるファーネスブラックの質量パーセント濃度は、32wt%であった。
(6-1-8. Example 7)
The thickness of the current collector of Example 7 was 56.6 μm. The ratio of the thickness of the first conductive resin layer to the thickness of the current collector was 50%. Nickel (Ni) was used as the conductive filler for the first layer and the second layer. The mass percent concentration of nickel in the second layer was 80 wt%. The mass percent concentration of nickel in the first layer was 70 wt%. Furness black was used as the conductive filler of the first conductive resin layer. The mass percent concentration of furnace black in the first conductive resin layer was 32 wt%.
 実施例1-7及び比較例1に関し、以下の表1にまとめる。 Examples 1-7 and Comparative Example 1 are summarized in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
 <6-2.試験>
 (6-2-1.プレス前後における抵抗値の比較)
 各実施例及び比較例における集電体の貫通抵抗値が集電体のプレス前後でどの程度変化するかに関し試験を行なった。具体的には、以下の手順で試験を行なった。まず、各実施例及び比較例の各々に関し、プレス前の貫通抵抗値を測定した。その後、各実施例及び比較例の各々に対して面プレスを行ない、各実施例及び比較例の各々に関しプレス後の貫通抵抗値を測定した。面プレスの方法は以下の通りである。プレス前における貫通抵抗値を測定したサンプルを大きさ100mm角、厚さ1.5mmの平滑なSUS板で挟み、圧力16.5kNにて10秒間プレスを行った[SA-401 テスター産業(株)製]。
Figure JPOXMLDOC01-appb-T000001
<6-2. Exam >
(6-2-1. Comparison of resistance values before and after pressing)
A test was conducted on how much the penetration resistance value of the current collector in each example and the comparative example changed before and after pressing the current collector. Specifically, the test was conducted according to the following procedure. First, the penetration resistance value before pressing was measured for each of the Examples and Comparative Examples. Then, surface pressing was performed on each of each of the Examples and Comparative Examples, and the penetration resistance value after pressing was measured for each of the Examples and Comparative Examples. The method of surface pressing is as follows. A sample whose penetration resistance value was measured before pressing was sandwiched between smooth SUS plates having a size of 100 mm square and a thickness of 1.5 mm, and pressed at a pressure of 16.5 kN for 10 seconds [SA-401 Tester Sangyo Co., Ltd.] Made].
 プレス前後における貫通抵抗値の測定方法は以下の通りである。各集電体から7cm角サンプルを裁断して取り出し、電気抵抗測定器[IMC-0240型 井元製作所(株)製]及び抵抗計[RM3548 HIOKI製]を用いて集電体の厚み方向(貫通方向)の抵抗値を測定した。電気抵抗測定器に2.16kgの荷重をかけた状態で集電体の抵抗値を測定し、荷重をかけてから60秒後の値をその集電体の抵抗値とした。下記式(1)に示すように、抵抗測定時の治具の接触表面の面積(3.14cm2)を抵抗値に乗算した値を貫通抵抗値(Ω・cm2)とした。
貫通抵抗値(Ω・cm2)=抵抗値(Ω)×3.14(cm2)・・・(1)
 なお、貫通抵抗値の測定方法は、他の試験においても共通である。
The method of measuring the penetration resistance value before and after pressing is as follows. A 7 cm square sample is cut and taken out from each collector, and the thickness direction (penetration direction) of the collector is used with an electric resistance measuring instrument [IMC-0240 type manufactured by Imoto Seisakusho Co., Ltd.] and a resistance meter [RM3548 HIOKI manufactured]. ) Was measured. The resistance value of the current collector was measured with a load of 2.16 kg applied to the electric resistance measuring instrument, and the value 60 seconds after the load was applied was taken as the resistance value of the current collector. As shown in the following equation (1), the value obtained by multiplying the resistance value by the area of the contact surface of the jig at the time of resistance measurement (3.14 cm 2 ) was defined as the penetration resistance value (Ω · cm 2 ).
Penetration resistance value (Ω ・ cm 2 ) = resistance value (Ω) × 3.14 (cm 2 ) ・ ・ ・ (1)
The method for measuring the penetration resistance value is also common to other tests.
 (6-2-2.温度毎の抵抗値の比較)
 実施例1-3及び比較例1における集電体の貫通抵抗値が周囲の温度変化によってどの程度影響を受けるかに関し試験を行なった。具体的には、以下の手順で試験を行なった。
(6-2-2. Comparison of resistance values for each temperature)
A test was conducted on how much the penetration resistance value of the current collectors in Examples 1-3 and Comparative Example 1 was affected by the change in ambient temperature. Specifically, the test was conducted according to the following procedure.
 (1)室温環境に集電体を2分間静置し、その後、集電体の貫通抵抗値を測定した。この測定結果を室温における抵抗値とした。 (1) The current collector was allowed to stand in a room temperature environment for 2 minutes, and then the penetration resistance value of the current collector was measured. This measurement result was used as the resistance value at room temperature.
 (2)60℃の恒温槽内に集電体を2分間静置し、その後、集電体を恒温槽から取り出し、貫通抵抗値を測定した。この測定結果を60℃における抵抗値とした。 (2) The current collector was allowed to stand in a constant temperature bath at 60 ° C. for 2 minutes, and then the current collector was taken out from the constant temperature bath and the penetration resistance value was measured. This measurement result was used as the resistance value at 60 ° C.
 (3)80℃の恒温槽内に集電体を2分間静置し、その後、集電体を恒温槽から取り出し、貫通抵抗値を測定した。この測定結果を80℃における抵抗値とした。 (3) The current collector was allowed to stand in a constant temperature bath at 80 ° C. for 2 minutes, and then the current collector was taken out from the constant temperature bath and the penetration resistance value was measured. This measurement result was used as the resistance value at 80 ° C.
 (4)100℃の恒温槽内に集電体を2分間静置し、その後、集電体を恒温槽から取り出し、貫通抵抗値を測定した。この測定結果を100℃における抵抗値とした。 (4) The current collector was allowed to stand in a constant temperature bath at 100 ° C. for 2 minutes, and then the current collector was taken out from the constant temperature bath and the penetration resistance value was measured. This measurement result was used as the resistance value at 100 ° C.
 (6-2-3.引裂強度の測定)
 実施例1-3及び比較例1における集電体に関し、TD(Transverse Direction)について、引裂強度を測定した。引裂強度の測定は、JIS-K-6732に準拠した方法によって行なわれた。
(6-2-3. Measurement of tear strength)
With respect to the current collectors in Examples 1-3 and Comparative Example 1, the tear strength was measured for TD (Transverse Direction). The tear strength was measured by a method according to JIS-K-6732.
 図4は、引裂き強度の測定に用いられた集電体10の試験片の形状を示す図である。引裂強度の測定においては、直角型引裂強さが測定された。具体的には、図4に示されるように切り出された試験片を引張試験機に試験片の軸方向と試験機のつかみ具方向とを一致させて正確に取り付けた。測定器としては、オートグラフ(島津精密万能試験機 オートグラフ AG-X 500N)が用いられた。試験速度は200mm/minとし、試験片切断時の強さが測定された。 FIG. 4 is a diagram showing the shape of the test piece of the current collector 10 used for measuring the tear strength. In the measurement of the tear strength, the right-angled tear strength was measured. Specifically, the test piece cut out as shown in FIG. 4 was accurately attached to the tensile tester by aligning the axial direction of the test piece with the gripping tool direction of the tester. As a measuring instrument, an autograph (Shimadzu precision universal testing machine Autograph AG-X 500N) was used. The test speed was 200 mm / min, and the strength at the time of cutting the test piece was measured.
 (6-2-4.カール状態の比較)
 実施例1-3及び比較例1における集電体のカールに関し試験を行なった。具体的には、以下の手順で試験を行なった。まず、各実施例及び比較例の各々に関し、MD200mm、TD100mmに切り出し、第1導電性樹脂層が上になる向きで机に平置きした。その後、各実施例及び比較例の各々に対して、1分間静置後のMF方向のカールを目視で官能評価した。評価基準は以下の通りとした。
A・・・端部のカールが45°未満(図5参照)
B・・・端部のカールが45°以上90°未満(図6参照)
C・・・端部のカールが90°以上180°未満(図7参照)
D・・・端部のカールが180°以上(図8参照)
 <6-3.試験結果>
 (6-3-1.プレス前後における抵抗値の比較結果)
 表2は、比較例1及び実施例1-3に関し、プレス前後における抵抗値の変化をまとめたものである。
(6-2-4. Comparison of curl state)
The curl of the current collectors in Examples 1-3 and Comparative Example 1 was tested. Specifically, the test was conducted according to the following procedure. First, each of the Examples and Comparative Examples was cut into MD 200 mm and TD 100 mm, and placed flat on a desk with the first conductive resin layer facing up. Then, the curls in the MF direction after standing for 1 minute were visually evaluated for each of the Examples and Comparative Examples. The evaluation criteria are as follows.
A ... The curl at the end is less than 45 ° (see Fig. 5)
B ... The curl at the end is 45 ° or more and less than 90 ° (see Fig. 6).
C ... The curl at the end is 90 ° or more and less than 180 ° (see Fig. 7).
D: Curl at the end is 180 ° or more (see Fig. 8)
<6-3. Test result>
(6-3-1. Comparison result of resistance value before and after pressing)
Table 2 summarizes the changes in resistance value before and after pressing with respect to Comparative Example 1 and Example 1-3.
Figure JPOXMLDOC01-appb-T000002
 表2に示されるように、比較例1と比べて、実施例1-3の各々においては、プレス前後における集電体の貫通抵抗値の上昇率(変化比)が抑制された。すなわち、集電体の厚さに対する第1導電性樹脂層の厚さが50%以上となることで、プレス前後における集電体の貫通抵抗値の上昇率(変化比)が抑制されることを確認することができた。
Figure JPOXMLDOC01-appb-T000002
As shown in Table 2, the rate of increase (change ratio) of the penetration resistance value of the current collector before and after pressing was suppressed in each of Examples 1-3 as compared with Comparative Example 1. That is, when the thickness of the first conductive resin layer is 50% or more with respect to the thickness of the current collector, the rate of increase (change ratio) of the penetration resistance value of the current collector before and after pressing is suppressed. I was able to confirm.
 表3は、実施例1,4-7に関し、プレス前後における抵抗値の変化をまとめたものである。 Table 3 summarizes the changes in resistance value before and after pressing for Examples 1 and 4-7.
Figure JPOXMLDOC01-appb-T000003
 表3に示されるように、実施例1と比べて、実施例4-7の各々においては、プレス前後における集電体の貫通抵抗値の上昇率(変化比)が抑制された。すなわち、第2導電性樹脂層における導電性フィラーの質量パーセント濃度が高くなる程、プレス前後における集電体の貫通抵抗値の上昇率(変化比)が抑制されることを確認することができた。
Figure JPOXMLDOC01-appb-T000003
As shown in Table 3, the rate of increase (change ratio) of the penetration resistance value of the current collector before and after pressing was suppressed in each of Examples 4-7 as compared with Example 1. That is, it was confirmed that the higher the mass percent concentration of the conductive filler in the second conductive resin layer, the more the rate of increase (change ratio) of the penetration resistance value of the current collector before and after pressing was suppressed. ..
 (6-3-2.温度毎の抵抗値の比較結果)
 表4は、比較例1及び実施例1-3に関し、温度毎での集電体の抵抗値の変化をまとめたものである。表5は、室温におけるデータを1.00とした場合に、温度毎で比較例1及び実施例1-3の各々の集電体の抵抗値がどのように変化するかをまとめたものである。
(6-3-2. Comparison result of resistance value for each temperature)
Table 4 summarizes the changes in the resistance value of the current collector for each temperature with respect to Comparative Example 1 and Example 1-3. Table 5 summarizes how the resistance values of the current collectors of Comparative Example 1 and Example 1-3 change for each temperature when the data at room temperature is 1.00. ..
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
 表4及び表5に示されるように、比較例1と比べて、実施例1-3の各々においては、温度上昇に伴なう集電体の貫通抵抗値の上昇率(変化比)が抑制された。すなわち、集電体の厚さに対する第1導電性樹脂層の厚さが50%以上となることで、温度上昇に伴なう集電体の貫通抵抗値の上昇率(変化比)が抑制されることを確認することができた。
Figure JPOXMLDOC01-appb-T000005
As shown in Tables 4 and 5, in each of Examples 1-3 as compared with Comparative Example 1, the rate of increase (change ratio) of the penetration resistance value of the current collector with the temperature rise is suppressed. Was done. That is, when the thickness of the first conductive resin layer is 50% or more with respect to the thickness of the current collector, the rate of increase (change ratio) of the penetration resistance value of the current collector with the temperature rise is suppressed. I was able to confirm that.
 (6-3-3.引裂強度の測定結果)
 表6は、比較例1及び実施例1-3に関し、引裂強度をまとめたものである。
(6-3-3. Measurement result of tear strength)
Table 6 summarizes the tear strengths of Comparative Example 1 and Example 1-3.
Figure JPOXMLDOC01-appb-T000006
 表6に示されるように、比較例1と比べて、実施例1-3の各々の引裂強度が強かった。すなわち、集電体の厚さに対する第1導電性樹脂層の厚さが50%以上となることで、引裂強度が強くなることを確認することができた。
Figure JPOXMLDOC01-appb-T000006
As shown in Table 6, the tear strength of each of Examples 1-3 was stronger than that of Comparative Example 1. That is, it was confirmed that the tear strength was increased when the thickness of the first conductive resin layer was 50% or more with respect to the thickness of the current collector.
 (6-3-4.カール状態の比較結果)
 表7は、比較例1及び実施例―3に関し、カール状態をまとめたものである。
(6-3-4. Comparison result of curl state)
Table 7 summarizes the curl states with respect to Comparative Example 1 and Example-3.
Figure JPOXMLDOC01-appb-T000007
 表7に示されるように、比較例1と比べて、実施例1-3の各々においては、カールが抑制された。
Figure JPOXMLDOC01-appb-T000007
As shown in Table 7, curl was suppressed in each of Examples 1-3 as compared with Comparative Example 1.
 10 集電体、100 第1導電性樹脂層、200 第2導電性樹脂層、210 第1層、220 第2層、500 製造装置、510 Tダイ、520,530,540 原料投入部。 10 current collector, 100 first conductive resin layer, 200 second conductive resin layer, 210 first layer, 220 second layer, 500 manufacturing equipment, 510 T-die, 520, 530, 540 raw material input section.

Claims (6)

  1.  リチウムイオン電池用の集電体であって、
     第1導電性フィラーを含む第1導電性樹脂層と、
     前記第1導電性樹脂層上に形成されており、第2導電性フィラーを含む第2導電性樹脂層とを備え、
     前記第1導電性フィラーは、導電性カーボンであり、
     前記第2導電性フィラーは、白金、金、銀、銅、SUS(Stainless Used Steel)、ニッケル及びチタンが含まれる群から選択される少なくとも1種類の金属を含み、
     前記第1導電性樹脂層の厚みは、前記集電体の厚みの50%以上である、集電体。
    A current collector for lithium-ion batteries
    The first conductive resin layer containing the first conductive filler and
    It is formed on the first conductive resin layer and includes a second conductive resin layer containing a second conductive filler.
    The first conductive filler is conductive carbon and is
    The second conductive filler contains at least one metal selected from the group containing platinum, gold, silver, copper, SUS (Stainless Used Steel), nickel and titanium.
    The thickness of the first conductive resin layer is 50% or more of the thickness of the current collector.
  2.  前記第1導電性樹脂層の厚みは、前記集電体の厚みの67%以上である、請求項1に記載の集電体。 The current collector according to claim 1, wherein the thickness of the first conductive resin layer is 67% or more of the thickness of the current collector.
  3.  前記第1導電性樹脂層の厚みは、前記集電体の厚みの75%以上である、請求項2に記載の集電体。 The current collector according to claim 2, wherein the thickness of the first conductive resin layer is 75% or more of the thickness of the current collector.
  4.  前記第2導電性樹脂層は、前記第1導電性樹脂層に近い第1層と、前記第1導電性樹脂層から遠い第2層とを含む、請求項1から請求項3のいずれか1項に記載の集電体。 Any one of claims 1 to 3, wherein the second conductive resin layer includes a first layer close to the first conductive resin layer and a second layer far from the first conductive resin layer. The current collector described in the section.
  5.  前記第2導電性フィラーはニッケルを含む、請求項4に記載の集電体。 The current collector according to claim 4, wherein the second conductive filler contains nickel.
  6.  前記第2層における前記金属の質量パーセント濃度は、前記第1層における前記金属の質量パーセント濃度よりも高い、請求項4又は請求項5に記載の集電体。 The current collector according to claim 4 or 5, wherein the mass percent concentration of the metal in the second layer is higher than the mass percent concentration of the metal in the first layer.
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WO2010117060A1 (en) * 2009-04-09 2010-10-14 日産自動車株式会社 Collector for secondary battery, and secondary battery using same
JP2018055967A (en) * 2016-09-29 2018-04-05 三洋化成工業株式会社 Current collector for lithium ion battery, lithium ion battery, and production method for current collector for lithium ion battery
JP2020068065A (en) * 2018-10-22 2020-04-30 三洋化成工業株式会社 Manufacturing method of resin collector for anode, manufacturing method of anode for lithium ion battery, and manufacturing method of lithium ion battery

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010117060A1 (en) * 2009-04-09 2010-10-14 日産自動車株式会社 Collector for secondary battery, and secondary battery using same
JP2018055967A (en) * 2016-09-29 2018-04-05 三洋化成工業株式会社 Current collector for lithium ion battery, lithium ion battery, and production method for current collector for lithium ion battery
JP2020068065A (en) * 2018-10-22 2020-04-30 三洋化成工業株式会社 Manufacturing method of resin collector for anode, manufacturing method of anode for lithium ion battery, and manufacturing method of lithium ion battery

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