electrode

Abstract

The solution is that the electrode has, in order from the side toward the thickness direction, a base material film, an inorganic oxide layer, a metal base layer, and a conductive carbon layer.

Description

Technical Field

[0001] This invention relates to electrodes. Background Technology

[0002] Previously, electrodes having a film substrate, a titanium thin film, and a carbon thin film sequentially arranged in the thickness direction were known (see, for example, Patent Document 1 below).

[0003] Regarding the electrode described in Patent Document 1, the conductivity is improved by using a titanium thin film, and the chemical stability is also improved over a short period of time.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: WO2016 / 013478 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, electrodes are sometimes immersed in electrolyte for extended periods. Electrodes require protection against damage under these conditions; that is, they need excellent electrolyte durability.

[0009] However, the electrode described in Patent Document 1 has the disadvantage of not having the aforementioned excellent electrolyte durability.

[0010] This invention provides an electrode with excellent electrolyte durability.

[0011] Methods for solving problems

[0012] The present invention (1) includes an electrode having a substrate film, an inorganic oxide layer, a metal substrate layer and a conductive carbon layer sequentially disposed on the side facing the thickness direction.

[0013] The present invention (2) includes the electrode described in (1), wherein the aforementioned metal substrate layer is capable of forming a carbide with the carbon of the aforementioned conductive carbon layer.

[0014] The present invention (3) includes the electrode described in (1) or (2), wherein the aforementioned inorganic oxide layer is a metal oxide layer or a half-metal oxide layer.

[0015] The present invention (4) includes the electrode described in (3), wherein the aforementioned metal oxide layer and the aforementioned metal substrate layer contain the same metal element.

[0016] The present invention (5) includes the electrode described in (4), wherein the aforementioned metal element is titanium.

[0017] The present invention (6) comprises the electrode of any one of (3) to (5), characterized in that the aforementioned half-metal oxide layer comprises silicon dioxide.

[0018] The present invention (7) comprises the electrode of any one of (1) to (6), wherein the thickness of the aforementioned metal oxide layer is 5 nm or more.

[0019] The present invention (8) includes any one of (1) to (7) electrodes, which are electrodes for electrochemical measurement.

[0020] The effects of the invention

[0021] The electrode of this invention has excellent electrolyte durability. Attached Figure Description

[0022] [ Figure 1 ] Figure 1 This is a cross-sectional view of one embodiment of the electrode of the present invention.

[0023] [ Figure 2 ] Figure 2 A cross-sectional view of an electrode with pinholes.

[0024] [ Figure 3 ] Figure 3 This is a cross-sectional view of the electrode of Comparative Example 1.

[0025] [ Figure 4 ] Figure 4 This is a cross-sectional view of the electrode in Comparative Example 2.

[0026] [ Figure 5 ] Figure 5 A to Figure 5 B is an OM image of the electrode in Example 1; Figure 5 A shows the electrode before immersion in the electrolyte. Figure 5 B shows the electrode after being immersed in the electrolyte.

[0027] [ Figure 6 ] Figure 6 A to Figure 6 B is the OM image of the electrode in Example 2; Figure 6 A shows the electrode before immersion in the electrolyte. Figure 6 B shows the electrode after being immersed in the electrolyte.

[0028] [ Figure 7 ] Figure 7 A to Figure 7 B is the OM image of the electrode in Comparative Example 1; Figure 7 A shows the electrode before immersion in the electrolyte. Figure 7 B shows the electrode after being immersed in the electrolyte.

[0029] [ Figure 8 ] Figure 8 A to Figure 8 B is the OM image of the electrode in Comparative Example 2; Figure 8 A shows the electrode before immersion in the electrolyte. Figure 8 B shows the electrode after being immersed in the electrolyte. Detailed Implementation

[0030] <One implementation>

[0031] Reference Figures 1 to 2 One embodiment of the electrode of the present invention will be described.

[0032] like Figure 1 As shown, electrode 1 has a specified thickness. Electrode 1 has a film-like (including sheet-like) structure. On the side facing the thickness direction, electrode 1 sequentially comprises a substrate film 2, an inorganic oxide layer 3, a metal substrate layer 4, and a conductive carbon layer 5. Specifically, electrode 1 comprises only the substrate film 2, the inorganic oxide layer 3, the metal substrate layer 4, and the conductive carbon layer 5.

[0033] The substrate film 2 has a specified thickness. Materials used as the substrate film 2 include, for example, inorganic and organic materials. They can be used alone or in combination. Inorganic materials include, for example, silicon and glass. They can be used alone or in combination. Organic materials include, for example, resin materials. Resin materials include, for example, polyester resin, acetate resin, polyethersulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, and polyphenylene sulfide resin. They can be used alone or in combination.

[0034] As the material for the substrate film 2, organic materials are preferred, and polyester resins are more preferred. Specifically, polyethylene terephthalate and polyethylene naphthalate are examples of polyester resins. Polyethylene terephthalate is a preferred polyester resin.

[0035] The thickness of the substrate film 2 is not particularly limited. For example, the thickness of the substrate film 2 is 2 μm or more, preferably 20 μm or more, and also, for example, 1000 μm or less, preferably 500 μm or less.

[0036] An inorganic oxide layer 3 is disposed on one side of the substrate film 2 along its thickness direction. Specifically, the inorganic oxide layer 3 is in contact with the entire thickness direction surface of the substrate film 2. The inorganic oxide layer 3 has a specified thickness.

[0037] As an inorganic oxide layer 3, examples include a metal oxide layer 3A or a half-metal oxide layer 3B.

[0038] The metal oxide layer 3A is in a passive state. Specifically, the passive state includes metal oxides. Examples of metal oxides include nickel oxide, cobalt oxide, chromium oxide, titanium oxide, aluminum oxide, tungsten oxide, molybdenum oxide, and composite oxides thereof. They can be used alone or in combination. From the viewpoint of further improving electrolyte durability, titanium oxide is preferred.

[0039] The half-metal oxide layer 3B is formed of an oxide of a half-metal. The half-metal is not limited. Examples of half-metals include silicon, antimony, germanium, and bismuth. Silicon is preferably a half-metal. Specifically, examples of oxides of half-metals include silicon oxide, antimony oxide, germanium oxide, and bismuth oxide. Additionally, borosilicate glass and other glasses can also be used as oxides of half-metals. From the viewpoint of further improving electrolyte durability, silicon oxide is preferably a half-metal oxide. Examples of silicon oxides include silicon dioxide and silicon monoxide, with silicon dioxide being preferred.

[0040] The thickness of the inorganic oxide layer 3 is not particularly limited. The thickness of the inorganic oxide layer 3 is, for example, 1 nm or more, preferably 5 nm or more, and also, for example, 50 nm or less, preferably 25 nm or less.

[0041] If the thickness of the inorganic oxide layer 3 is above the aforementioned lower limit, then the uniformity of the inorganic oxide layer 3 is excellent throughout the entire planar direction. The planar direction is the direction orthogonal to the thickness direction. Therefore, the inorganic oxide layer 3 becomes a continuous film, and the effect of improved electrode durability can be expected.

[0042] On the other hand, if the thickness of the inorganic oxide layer 3 is below the aforementioned upper limit, the conductivity of the inorganic oxide layer 3 (especially the metal oxide layer 3A) is also excellent.

[0043] A metal substrate 4 is disposed on one side of the inorganic oxide layer 3 along its thickness direction. Specifically, the metal substrate 4 is in contact with the entire thickness direction of the inorganic oxide layer 3. The metal substrate 4 has a predetermined thickness.

[0044] The material of the metal substrate 4 is a metal. Preferably, such a metal is capable of forming a carbide with the carbon of the conductive carbon layer 5, as described below. Specifically, examples of such metals include: Group 2 elements of the periodic table; Group 4 to Group 14 elements; and alloys thereof. They can be used alone or in combination.

[0045] In addition, the metal substrate 4 and the metal oxide layer 3A contain, for example, the same metal element.

[0046] Regarding the metal used as the material for the metal substrate layer 4, from the viewpoint of ensuring the chemical stability of the conductive carbon layer 5, elements from Group 4 are preferred, titanium and zirconium are more preferred, and titanium is even more preferred.

[0047] Particularly preferably, the metal oxide layer 3A and the metal substrate layer 4 contain titanium as an element. If the metal oxide layer 3A and the metal substrate layer 4 contain titanium, the adhesion between the metal oxide layer 3A and the metal substrate layer 4 can be improved, which is advantageous. When the metal oxide layer 3A contains titanium, the material of the metal oxide layer 3A is titanium oxide. The material of the metal substrate layer 4 is titanium as a metal.

[0048] A conductive carbon layer 5 is disposed on one side of the metal substrate layer 4 in the thickness direction. Specifically, the conductive carbon layer 5 is in contact with the entire thickness direction side of the metal substrate layer 4. The conductive carbon layer 5 has a predetermined thickness.

[0049] The conductive carbon layer 5 is made of carbon, preferably having sp 2 Key and sp 3 Carbon atoms with sp bonds. 2 Key and sp 3 The carbon atoms in the bonds possess both graphitic and diamond structures. (The sentence fragment about sp is incomplete and lacks context.) 3 The number of bondsed atoms relative to the number of sp atoms 3 The number of atoms bonded and the sp 2 The ratio of the sum of the number of bonded atoms (sp) 3 / sp 3 +sp 2 There are no specific limitations. The above ratio (sp) 3 / sp 3 +sp 2 For example, it is 0.1 or higher, preferably 0.2 or higher; and, for example, it is 0.9 or lower, preferably 0.5 or lower. Regarding the ratio (sp... 3 / sp 3 +sp 2 Regarding the spectrum obtained by measuring one side of the conductive carbon layer 5 in the thickness direction using X-ray photoelectron spectroscopy, based on sp... 2 peak intensity of the bond and sp 3 The peak intensity of the bond is calculated.

[0050] In the thickness direction of the conductive carbon layer 5, the oxygen-to-carbon concentration ratio (O / C) is not particularly limited. The aforementioned concentration ratio (O / C) is, for example, 0.15 or less, preferably 0.10 or less, and also, for example, more than 0.00, more than 0.01, more than 0.02, and further more than 0.03. Regarding the concentration ratio, it is calculated based on the peak area of ​​C1s and the peak area of ​​O1s in the spectrum obtained by measuring the thickness direction of the conductive carbon layer 5 using X-ray photoelectron spectroscopy.

[0051] The surface resistivity of one side of the conductive carbon layer 5 along its thickness direction is not particularly limited. For example, the surface resistivity of the conductive carbon layer 5 is 1.0 × 10⁻⁶. 4 Ω / □ or less, preferably 1.0 × 10 3 Below Ω / □. Surface resistivity can be measured using the four-terminal method according to JIS K 7194.

[0052] The thickness of the conductive carbon layer 5 is not particularly limited. The thickness of the conductive carbon layer 5 is, for example, 5 nm or more, more preferably 10 nm or more, and also, for example, 200 nm or less, more preferably 100 nm or less. The thickness of the conductive carbon layer 5 is calculated by measuring the X-ray reflectivity.

[0053] Furthermore, a carbide layer (not shown) is preferably formed at the interface between the conductive carbon layer 5 and the metal substrate layer 4. The carbide layer is formed from a carbide that is a compound formed from the metal of the metal substrate layer 4 and the carbon of the conductive carbon layer 5. The carbide layer enhances the adhesion between the conductive carbon layer 5 and the metal substrate layer 4. In this case, the electrode 1 sequentially comprises a substrate film 2, an inorganic oxide layer 3, a metal substrate layer 4, a carbide layer (not shown), and a conductive carbon layer 5 on the thickness side.

[0054] Next, the manufacturing method of electrode 1 will be described. First, a substrate film 2 is prepared. Then, an inorganic oxide layer 3, a metal substrate layer 4, and a conductive carbon layer 5 are sequentially formed on one side of the substrate film 2 in the thickness direction.

[0055] Methods for forming the inorganic oxide layer 3 include, for example, dry methods and wet methods. Dry methods are preferred. Examples of dry methods include PVD (physical vapor deposition) and CVD (chemical vapor deposition). PVD is preferred as a dry method. Examples of PVD methods include sputtering, vacuum evaporation, laser evaporation, and ion plating (arc evaporation). Sputtering is preferred as a PVD method. The sputtering method is not particularly limited. Examples of sputtering methods include unbalanced magnetron sputtering (UBM sputtering), high-power pulsed sputtering, electron cyclotron resonance sputtering, RF sputtering, DC sputtering (DC magnetron sputtering), DC pulsed sputtering, and ion beam sputtering.

[0056] In addition, sputtering methods can, for example, use sputtering gases containing oxygen and inactive gases, and targets formed of inorganic materials.

[0057] Argon can be cited as an example of an inactive gas. The oxygen flow rate ratio relative to the total flow rate of the sputtering gas is, for example, 0.01 or more, preferably 0.05, and also, for example, less than 0.5, preferably less than 0.2.

[0058] As inorganic substances, examples include metals and half-metals.

[0059] Examples of metals include metallic elements that form metal oxides. Examples of metals include, for instance, nickel, cobalt, chromium, titanium, aluminum, tungsten, molybdenum, and their alloys. From the viewpoint of chemical stability, titanium is preferred.

[0060] Examples of semimetals include those mentioned above, with silicon being a preferred example.

[0061] As a method for forming the metal substrate layer 4, the same method as described above for forming the inorganic oxide layer 3 can be cited. However, when forming the metal substrate layer 4 using a sputtering method, a sputtering gas containing only inactive gases and no oxygen is used.

[0062] Furthermore, as the target material, it is preferable to use the same target material used in the formation of the metal oxide layer 3A, and more preferably titanium. Since a titanium target can be shared in both the formation of the metal oxide layer 3A and the formation of the metal substrate layer 4, the design of the manufacturing equipment becomes easier.

[0063] As a method for forming the conductive carbon layer 5, the same method as described above for forming the inorganic oxide layer 3 can be cited. However, when forming the conductive carbon layer 5 using a sputtering method, a sputtering gas containing only inactive gases and no oxygen is used. When forming the conductive carbon layer 5 using a sputtering method, carbon is used as the target material, and sintered carbon is preferred. Then, the conductive carbon layer 5 can be surface-treated as needed.

[0064] <Effects of one implementation method>

[0065] Furthermore, the electrode 1 has a substrate film 2, an inorganic oxide layer 3, a metal substrate layer 4, and a conductive carbon layer 5 sequentially on the side facing the thickness direction, thus exhibiting excellent electrolyte durability.

[0066] However, as Figure 2 As shown, in electrode 1, pinholes 6 inevitably form due to its manufacturing process. Pinholes 6 are holes that penetrate the inorganic oxide layer 3, the metal substrate layer 4, and the conductive carbon layer 5 in the thickness direction. For example, during the handling of the substrate film 2, if foreign matter (dust) inevitably accumulates on one side of the substrate film 2 in the thickness direction, the inorganic oxide layer 3, the metal substrate layer 4, and the conductive carbon layer 5 are formed on the side of the foreign matter in the thickness direction. Because the adhesion between the foreign matter and the substrate film 2 is significantly low, when the foreign matter detaches from the thickness direction of the substrate film 2, the corresponding portions of the inorganic oxide layer 3, the metal substrate layer 4, and the conductive carbon layer 5 also detach. Thus, the aforementioned pinholes 6 are inevitably formed.

[0067] Furthermore, if electrode 1 is immersed in a corrosive electrolyte, the pinhole 6 will be filled with electrolyte.

[0068] However, as Figure 3 As shown in Patent Document 1, for an electrode 1 lacking an inorganic oxide layer 3, as indicated by the thick arrow, the electrolyte seeps through the pinhole 6 to the interface between the metal substrate layer 4 and the substrate film 2. Therefore, the metal substrate layer 4 is easily peeled off from the thickness direction of the substrate film 2. Therefore, Figure 3 Electrode 1 has insufficient electrolyte durability.

[0069] In this application, electrolyte durability refers to the fact that the conductive carbon layer 5 is not easily damaged when the electrode 1 is immersed in the electrolyte for a long period of time. Specifically, electrolyte durability means that the conductive carbon layer 5 is not easily damaged when the electrode 1 is immersed in the electrolyte for, for example, more than 5 days, more than 10 days, more than 15 days, or more than 20 days.

[0070] In addition, such as Figure 4 As shown, even with a layer configuration where the formation order of the inorganic oxide layer 3 and the metal substrate layer 4 is changed, the metal substrate layer 4 remains in contact with the thickness direction of the substrate film 2. Therefore, as... Figure 4 As shown by the arrow, the electrolyte seeps from the pinhole 6 into the interface between the metal substrate layer 4 and the substrate film 2.

[0071] However, in this embodiment, even if... Figure 2As shown, the pinhole 6 is filled with electrolyte, and an inorganic oxide layer 3 is also disposed between the metal substrate layer 4 and the substrate film 2. Therefore, the inorganic oxide layer 3 can suppress the penetration of electrolyte into the space between the metal substrate layer 4 and the substrate film 2. That is, the inorganic oxide layer 3 can function as a barrier layer against electrolyte. Specifically, the inner peripheral surface 7 of the inorganic oxide layer 3 facing the pinhole 6 becomes a blocking part.

[0072] On the other hand, there is a concern that the electrolyte may penetrate to the interface between the conductive carbon layer 5 and the metal substrate layer 4, potentially causing the conductive carbon layer 5 to peel off from the metal substrate layer 4. However, in this embodiment, a carbide layer is formed at the interface between the conductive carbon layer 5 and the metal substrate layer 4. Therefore, the adhesion between the conductive carbon layer 5 and the metal substrate layer 4 is increased, suppressing the aforementioned penetration. Consequently, peeling of the conductive carbon layer 5 off the metal substrate layer 4 can also be prevented.

[0073] Furthermore, if the metal oxide layer 3A and the metal substrate layer 4 are made of the same metal element, the adhesion between them can be improved. Moreover, since the metal oxide layer 3A and the metal substrate layer 4 can use a target formed from the same metal element, a common film-forming chamber can be used. Therefore, the electrode 1 can be manufactured using compact manufacturing equipment.

[0074] More specifically, if both the metal oxide layer 3A and the metal substrate layer 4 contain titanium as an element, the electrode 1 exhibits excellent chemical stability. Furthermore, since a titanium target is shared in the formation of both the metal oxide layer 3A and the metal substrate layer 4, the design of the manufacturing equipment becomes easier.

[0075] Furthermore, if the inorganic oxide layer 3 is a half-metal oxide layer 3B, then the half-metal oxide layer 3B can be used to effectively suppress the penetration of electrolyte into the space between the metal substrate layer 4 and the substrate film 2. Therefore, the electrode 1 with the half-metal oxide layer 3B has excellent electrolyte durability.

[0076] Furthermore, if the thickness of the inorganic oxide layer 3 is 5 nm or more, the uniformity of the inorganic oxide layer 3 is excellent throughout the surface direction.

[0077] <Application of Electrode 1>

[0078] The application of electrode 1 is not particularly limited. For example, electrode 1 can be used for electrochemical measurements. Specifically, it can be configured in an electrochemical measurement system in which electrode 1 is used as the working electrode.

[0079] Example

[0080] The following examples and comparative examples illustrate the present invention in more detail. It should be noted that the present invention is not limited by the examples and comparative examples. Furthermore, the specific numerical values ​​of proportions (including proportions), physical property values, parameters, etc., used in the following description can be replaced by the corresponding upper limit values ​​(defined as "below" or "less than") or lower limit values ​​(defined as "above" or "exceeding") of the proportions (including proportions), physical property values, parameters, etc., described in the "Specific Embodiments" above.

[0081] Example 1

[0082] Prepare a substrate film 2 with a thickness of 50 μm formed from polyethylene terephthalate.

[0083] Next, a metal oxide layer 3A (inorganic oxide layer 3) made of titanium oxide is formed on one side of the substrate film 2 in the thickness direction using magnetron sputtering. The conditions for magnetron sputtering are shown below.

[0084] Target material: titanium

[0085] Target power: 100W

[0086] Sputtering gases: argon and oxygen (at a flow rate ratio of 9:1).

[0087] Sputtering chamber pressure: 0.2 Pa

[0088] The thickness of the metal oxide layer 3A is 5 nm.

[0089] A titanium-based metal substrate layer 4 is formed on one side of the metal oxide layer 3A along its thickness direction using magnetron sputtering. The conditions for magnetron sputtering are shown below.

[0090] Target material: titanium

[0091] Target power: 100W

[0092] Sputtering gas: Argon

[0093] Sputtering chamber pressure: 0.2 Pa

[0094] The thickness of the metal substrate 4 is 12 nm.

[0095] A conductive carbon layer 5 is formed on one side of the metal substrate layer 4 in the thickness direction using DC pulse sputtering. The conditions for DC pulse sputtering are shown below.

[0096] Target material: sintered carbon

[0097] Argon pressure: 0.4 Pa

[0098] Target power: 3.3W / cm 2

[0099] Temperature: Below 120℃

[0100] The surface resistivity of conductive carbon layer 5 is 130 Ω / □. The ratio (sp) in conductive carbon layer 5... 3 / sp 3 +sp 2 The oxygen concentration ratio (O / C) in conductive carbon layer 5 is 0.35. The oxygen-to-carbon concentration ratio (O / C) in conductive carbon layer 5 is 0.06. The thickness of conductive carbon layer 5 is 30 nm.

[0101] Thus, an electrode 1 was manufactured having a substrate film 2, a metal oxide layer 3A, a metal substrate layer 4, and a conductive carbon layer 5 sequentially arranged on one side in the thickness direction.

[0102] Example 2

[0103] Except for changing the thickness of the metal oxide layer 3A to 2nm, it was treated in the same way as in Example 1.

[0104] Example 3

[0105] Except for forming a half-metal oxide layer 3B instead of a metal oxide layer 3A, the process is the same as in Example 1. That is, a half-metal oxide layer 3B (inorganic oxide layer 3) made of silicon dioxide is formed on one side of the substrate film 2 in the thickness direction using magnetron sputtering. The conditions for magnetron sputtering are as follows.

[0106] Target material: silicon

[0107] Target power: 700W

[0108] Sputtering gases: argon and oxygen (7:3 by flow rate).

[0109] Sputtering chamber pressure: 0.3 Pa

[0110] The thickness of the semi-metal oxide layer 3B is 10 nm.

[0111] Example 4

[0112] Except for changing the thickness of the semi-metal oxide layer 3B to 5 nm, it was processed in the same way as in Example 1.

[0113] Comparative Example 2

[0114] Except for the absence of metal oxide layer 3A, the treatment is the same as in Example 1. That is, as in Example 1. Figure 3 As shown, the electrode 1 has a substrate film 2, a metal substrate layer 4, and a conductive carbon layer 5 sequentially on the side facing the thickness direction.

[0115] Comparative Example 1

[0116] Except for changing the formation order of the metal oxide layer 3A and the metal substrate layer 4, the process is the same as in Example 1. That is, as in Example 1. Figure 4 As shown, the electrode 1 has a substrate film 2, a metal substrate layer 4, a metal oxide layer 3A, and a conductive carbon layer 5 sequentially on the side facing the thickness direction.

[0117] <Evaluation>

[0118] For each embodiment to each comparative example of electrode 1, the following items were evaluated. The results are shown in Table 1.

[0119] <Electrolyte Durability>

[0120] On one side of the conductive carbon layer 5 along its thickness direction, such as Figure 1 , Figure 3 and Figure 4 As shown by the respective imaginary lines, attach the insulating tape 9. The insulating tape 9 has an opening 8 with a diameter of 2mm.

[0121] Electrode 1 and insulating tape 9 were immersed in 0.1M nitric acid solution for 56 days.

[0122] Optical microscope images (hereinafter referred to as OM images) of electrode 1 and insulating tape 9 before and after impregnation are shown in the figure. Figure 5 A to Figure 8 B. It should be noted that, Figures 5 to 8 Examples 1 to 2 are respectively. Figure 5 A is electrode 1 before immersion in Example 1. Figure 5 B is electrode 1 after impregnation in Example 1. Figure 6 A to Figure 8 B and the above Figure 5 A to Figure 5 B is the same.

[0123] Based on the OM images after impregnation, the electrolyte durability is evaluated according to the following benchmarks.

[0124] ○: By Figure 5 As can be seen from B, virtually no damage caused by pinhole formation was observed.

[0125] △: by Figure 6 As can be seen from B, the damage site caused by pinhole formation was slightly observed.

[0126] ×: By Figure 7 B and Figure 8 As can be seen from B, damage caused by pinhole formation was observed to a considerable extent.

[0127] <Electrode Characteristics>

[0128] Using a potentiostat, the potential window of electrode 1 in each embodiment and each comparative example was measured. The electrode characteristics of electrode 1 were thus evaluated. The potential window refers to the voltage range within which no current flows even when voltage or current is applied; a wider potential window indicates better electrode characteristics of electrode 1.

[0129] An electrochemical measurement system was constructed, comprising electrode 1 as the active electrode. It should be noted that this electrochemical measurement system includes an Ag / AgCl electrode as the reference electrode and a Pt electrode as the counter electrode.

[0130] Then, electrode 1 was immersed in a 0.1M sulfuric acid solution. Next, the potential was scanned for electrode 1, reaching 500 μA / cm. 2 The width of the potential at a given time is defined as the potential window.

[0131] As shown in Table 1, in any of Examples 1 to Comparative Example 2, the potential window is 3.7 or higher, so the electrode characteristics of electrode 1 before impregnation are good.

[0132] [Table 1]

[0133]

[0134] It should be noted that the above-described invention is provided as an example embodiment of the present invention, but it is merely an example and should not be interpreted as limiting. Variations of the present invention known to those skilled in the art are included within the scope of the claims.

[0135] Industrial availability

[0136] Electrodes can be used, for example, for electrochemical measurements.

[0137] Explanation of reference numerals in the attached figures

[0138] 1 Electrode

[0139] 2. Substrate film

[0140] 3 Inorganic oxide layer

[0141] 3A Metal Oxide Layer

[0142] 3B semi-metal oxide layer

[0143] 4. Metal substrate layer

[0144] 5. Conductive carbon layer

Claims

1. An electrode, characterized in that, The substrate film, inorganic oxide layer, metal substrate layer, and conductive carbon layer are sequentially provided on the side facing the thickness direction. The carbon in the conductive carbon layer has sp 2 Key and sp 3 The key is these two.

2. The electrode as described in claim 1, characterized in that, The metal substrate layer can form carbides with the carbon in the conductive carbon layer.

3. The electrode as described in claim 1 or 2, characterized in that, The inorganic oxide layer is a metal oxide layer or a half-metal oxide layer.

4. The electrode as described in claim 3, characterized in that, The metal oxide layer and the metal substrate layer contain the same metal elements.

5. The electrode as described in claim 4, characterized in that, The metallic element is titanium.

6. The electrode as described in claim 3, characterized in that, The semi-metal oxide layer contains silicon dioxide.

7. The electrode as described in claim 1 or 2, characterized in that, The thickness of the inorganic oxide layer is 5 nm or more.

8. The electrode as claimed in claim 6, characterized in that, The thickness of the inorganic oxide layer is 5 nm or more.

9. The electrode as described in claim 1 or 2, characterized in that, Electrode used for electrochemical measurements.

10. The electrode as claimed in claim 6, characterized in that, Electrode used for electrochemical measurements.

11. The electrode as claimed in claim 7, characterized in that, Electrode used for electrochemical measurements.

12. The electrode as claimed in claim 8, characterized in that, Electrode used for electrochemical measurements.

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