Preparation method of high-conductivity interlayer copper foil anode

Abstract

The invention belongs to the technical field of a process for preparing an anode plate by a thermal decomposition method, and particularly relates to a preparation method of a high-conductivity interlayer copper foil anode, which comprises the following steps of: pretreating a titanium alloy, electrodepositing and plating nickel, and preparing and coating an iridium tantalum solution. According to the invention, the nickel plating intermediate layer is electrodeposited, so that the electrocatalytic activity of the Ti / IrO2-Ta2O5 anode is enhanced, and the electrolysis durability of the Ti / IrO2-Ta2O5 anode in a sulfuric acid solution is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of anode plate preparation by thermal decomposition method, and in particular relates to a method for preparing a high-conductivity intermediate layer copper foil anode. Background Art

[0002] Copper foil is called the "neural network" for electronic products to communicate with power transmission, and has been widely used in communication equipment, lithium-ion batteries, automobiles and other fields. However, the electrolytic copper foil manufacturing process conditions are relatively harsh, usually at high current density (6000 ~ 10000A·m -2 ) and high sulfuric acid concentration (100g·L -1 ) environment. 2 -Ta 2 O 5 The anode is widely used in the field of electrolytic copper foil because of its shorter electrode spacing, smaller oxygen evolution potential and lower cell pressure.

[0003] The prior art directly immerses a smooth titanium plate into a mixture of hydrofluoric acid, nitric acid, hydrogen peroxide and corrosion inhibitor. After 5-10 minutes, the surface of the titanium substrate becomes rough and scratchy. This process is dangerous to operate, and experiments have found that the coating electrode potential obtained by this method is very high because the surface roughness is poorly uniform, the coating adhesion is not strong, it is easy to fall off, and the electrode passivation phenomenon occurs.

[0004] In H 2 SO 4 Ti / IrO in the system medium 2 -Ta 2 O 5 When the anode works under high current density conditions, the coating is affected by multiple factors such as electrolyte and oxygen erosion. The surface crack areas and locations with poor film-substrate bonding are prone to dissolution and peeling, which in turn causes the titanium substrate surface to passivate, the coating's electrocatalytic activity to weaken, and it gradually fails. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a method for preparing a high-conductivity intermediate layer copper foil anode, which adopts the electroplating nickel intermediate layer to not only make the Ti / IrO 2 -Ta 2 O 5 The electrocatalytic activity of the anode is enhanced, and the Ti / IrO 2 -Ta 2 O 5 Anode electrolysis durability in sulfuric acid solution.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a high-conductivity intermediate layer copper foil anode comprises the following steps:

[0008] Step 1, titanium alloy pretreatment: the pretreatment includes sandblasting, acid etching, cleaning, and drying;

[0009] Step 2, electroplating nickel: using the titanium alloy pretreated in step 1 as an anode and the titanium plate as a cathode in an electroplating solution for electroplating deposition to prepare a nickel intermediate layer; the electroplating solution comprises: nickel sulfate, nickel chloride, boric acid, sodium sulfate, and sodium dodecyl sulfate;

[0010] Step 3, preparing an iridium-tantalum solution: dissolving an iridium source and a tantalum source in an organic solvent;

[0011] Step 4, coating and sintering: coating the iridium-tantalum solution prepared in step 3 on the surface of the nickel intermediate layer, drying and sintering and heat preservation, repeating for several times to obtain the iridium-tantalum active coating.

[0012] Preferably, the concentrations of the components in the electroplating solution of step 2 are: nickel sulfate concentration is 120-240 g / L, nickel chloride concentration is 6-20 g / L, boric acid concentration is 3-8 g / L, sodium sulfate concentration is 10-20 g / L, and sodium dodecyl sulfate concentration is 1-5 g / L.

[0013] Preferably, the current density during electroplating in step 2 is 0.5A / dm 2 -2A / dm 2 , the electroplating time is 10min-60min.

[0014] Preferably, the preparation method of the iridium-tantalum solution in step 3 is specifically as follows: chloroiridic acid and tantalum ethoxide are sequentially dissolved in n-butanol solution to prepare the solution.

[0015] Preferably, the mass of iridium ions in the iridium-tantalum solution accounts for 60% to 80% of the mass of total metal ions, the mass of tantalum ions accounts for 20% to 40% of the mass of total metal ions, and the total metal ion concentration of the solution is 0.2-0.5 mol·L -1 .

[0016] Preferably, the specific operation of the coating and sintering in step 4 is: drying the titanium alloy coated with the iridium-tantalum solution; placing the dried titanium alloy in a muffle furnace at 420°C and sintering for 25 minutes; repeating the above coating and sintering steps 12 times, and placing the last time in a muffle furnace at 550°C and keeping warm for 2 hours, to obtain the iridium-tantalum active coating.

[0017] Preferably, the sandblasting sand mold in step 1 is made of any one of brown corundum, white corundum and steel sand.

[0018] Preferably, after the sandblasting, the surface roughness of the titanium alloy is 6 μm<Ra<9 μm.

[0019] Preferably, the acid etching is to place the sandblasted titanium alloy in a slightly boiling 15%-20% oxalic acid solution for etching for 2-5 hours.

[0020] Preferably, the cleaning and drying are to rinse the acid-etched titanium alloy with deionized water for 10 minutes and then dry it.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) Compared with the thermal decomposition method, the electrodeposition of nickel intermediate layer makes Ti / IrO 2 -Ta 2 O 5 The conductivity of the coating is enhanced, and the electrocatalytic activity increases accordingly. Under the action of the electric field, Cu 2+ Uniformly enrich, reduce and precipitate copper;

[0023] (2) Compared with the thermal decomposition method, the Ti / IrO 2 -Ta 2 O 5 The coating's anti-passivation ability is enhanced, which is beneficial to hinder the penetration of electrolyte in the cracks on the surface of the iridium-tantalum active coating, prevent passivation at the fine grain boundaries of the titanium substrate, and significantly improve the coating's service life;

[0024] (3) Compared with the thermal decomposition method, the thermal conductivity of the intermediate layer of electroplated nickel is better, which can avoid the phenomenon of electric shock caused by the heat generated by the virtual contact of the substrate, causing the coating to be ablated. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Preparation of Ti / IrO before and after electroplating nickel intermediate layer 2 -Ta 2 O 5 SEM scanning images of the anode, where (a) is the Ti / IrO prepared before nickel electroplating 2 -Ta 2 O 5 SEM scanning image of anode surface morphology, (b) Ti / IrO prepared after nickel electrodeposition 2 -Ta 2 O 5 Scanning electron microscope image of anode surface morphology.

[0026] Figure 2 Preparation of Ti / IrO before and after electroplating nickel intermediate layer 2 -Ta 2 O 5 Cyclic voltammogram of the anode.

[0027] Figure 3 Preparation of Ti / IrO before and after electroplating nickel intermediate layer2 -Ta 2 O 5 Anode enhancement life curve. DETAILED DESCRIPTION

[0028] The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0029] The method for preparing a high-conductivity intermediate layer copper foil anode provided by the present invention comprises the following steps:

[0030] Step 1, titanium alloy pretreatment: including sandblasting, acid etching, cleaning, and drying; the specific operation is: use any one of brown corundum, white corundum, and steel sand for sandblasting to make the surface roughness of the substrate reach 6μm<Ra<9μm, then place it in a slightly boiling 15%-20% oxalic acid solution for etching for 2-5h, and finally rinse with deionized water for 10min, and dry it in an oven for use.

[0031] Step 2, electroplating nickel: The titanium alloy pretreated in step 1 is used as the anode and the titanium plate is used as the cathode in the electroplating solution at 0.5A / dm 2 -2A / dm 2 Electroplating is performed for 10 min-60 min under current density conditions to prepare a nickel intermediate layer; the composition and concentration of the electroplating solution are: nickel sulfate concentration is 120-240 g / L, nickel chloride concentration is 6-20 g / L, boric acid concentration is 3-8 g / L, sodium sulfate concentration is 10-20 g / L, and sodium dodecyl sulfate concentration is 1-5 g / L.

[0032] Step 3, preparing an iridium-tantalum solution: dissolving an iridium source and a tantalum source in an organic solvent; the specific operation is: dissolving chloroiridic acid and tantalum ethoxide in a n-butanol solution in turn to prepare the iridium-tantalum solution, wherein the mass of iridium ions in the iridium-tantalum solution accounts for 60%-80% of the mass of total metal ions, the mass of tantalum ions accounts for 20%-40% of the mass of total metal ions, and the total metal ion concentration of the solution is 0.2-0.5 mol·L -1 .

[0033] Step 4, coating and sintering: Use a brush to evenly coat the iridium-tantalum solution prepared in step 3 on the surface of the nickel intermediate layer, place it in an oven for drying, and place the dried titanium alloy in a muffle furnace at 420°C for sintering for 25 minutes; repeat the above coating and sintering steps 12 times, and place it in a muffle furnace at 550°C for the last time for insulation for 2 hours to obtain the iridium-tantalum active coating.

[0034] Example 1

[0035] A method for preparing a high-conductivity intermediate layer copper foil anode comprises the following steps:

[0036] Step 1, titanium alloy pretreatment: use brown corundum for sandblasting to make the surface roughness of the substrate reach 6μm<Ra<7μm, then place it in a slightly boiling 20% ​​oxalic acid solution for etching for 2h, finally rinse with deionized water for 10min, and dry it in an oven for use.

[0037] Step 2, electroplating nickel: the titanium alloy pretreated in step 1 is used as the anode, and the titanium plate is used as the cathode and placed in the electroplating solution at 1A / dm 2 Electroplating was performed for 40 min under current density conditions to prepare a nickel intermediate layer; the composition and concentration of the electroplating solution were as follows: nickel sulfate concentration was 160 g / L, nickel chloride concentration was 10 g / L, boric acid concentration was 5 g / L, sodium sulfate concentration was 15 g / L, and sodium dodecyl sulfate concentration was 2 g / L.

[0038] Step 3, preparing an iridium-tantalum solution: dissolving chloroiridic acid and tantalum ethoxide in n-butanol solution in turn, controlling the mass ratio of iridium-tantalum ions in the solution to be 8:2, and the total metal ion concentration of the iridium-tantalum solution to be 0.2 mol·L -1 .

[0039] Step 4, coating and sintering: Use a brush to evenly coat the iridium-tantalum solution prepared in step 3 on the surface of the nickel intermediate layer, place it in an oven for drying, and place the dried titanium alloy in a muffle furnace at 420°C for sintering for 25 minutes; repeat the above coating and sintering steps 12 times, and place it in a muffle furnace at 550°C for the last time for insulation for 2 hours to obtain the iridium-tantalum active coating.

[0040] Example 2

[0041] A method for preparing a high-conductivity intermediate layer copper foil anode comprises the following steps:

[0042] Step 1, titanium alloy pretreatment: sandblasting with steel sand to make the surface roughness of the substrate reach 7μm<Ra<8μm, then etched in a slightly boiling 18% oxalic acid solution for 3h, finally rinsed with deionized water for 10min, and dried in an oven for use.

[0043] Step 2, electroplating nickel: The titanium alloy pretreated in step 1 is used as the anode and the titanium plate is used as the cathode in the electroplating solution at 0.5A / dm 2 Electroplating was performed for 60 min under current density conditions to prepare a nickel intermediate layer; the composition and concentration of the electroplating solution were as follows: nickel sulfate concentration was 120 g / L, nickel chloride concentration was 6 g / L, boric acid concentration was 3 g / L, sodium sulfate concentration was 10 g / L, and sodium dodecyl sulfate concentration was 1 g / L.

[0044] Step 3, preparing an iridium-tantalum solution: dissolving chloroiridic acid and tantalum ethoxide in n-butanol solution in turn, controlling the mass ratio of iridium-tantalum ions in the solution to be 7:3, and the total metal ion concentration of the iridium-tantalum solution to be 0.3 mol·L -1 .

[0045] Step 4, coating and sintering: Use a brush to evenly coat the iridium-tantalum solution prepared in step 3 on the surface of the nickel intermediate layer, place it in an oven for drying, and place the dried titanium alloy in a muffle furnace at 420°C for sintering for 25 minutes; repeat the above coating and sintering steps 12 times, and place it in a muffle furnace at 550°C for the last time for insulation for 2 hours to obtain the iridium-tantalum active coating.

[0046] Example 3

[0047] A method for preparing a high-conductivity intermediate layer copper foil anode comprises the following steps:

[0048] Step 1, titanium alloy pretreatment: sandblasting with white corundum to make the surface roughness of the substrate reach 8μm<Ra<9μm, then etched in a slightly boiling 15% oxalic acid solution for 5h, finally rinsed with deionized water for 10min, and dried in an oven for later use.

[0049] Step 2, electroplating nickel: the titanium alloy pretreated in step 1 is used as the anode, and the titanium plate is used as the cathode and placed in the electroplating solution at 2A / dm 2 Electroplating was performed for 10 min under current density conditions to prepare a nickel intermediate layer; the composition and concentration of the electroplating solution were as follows: nickel sulfate concentration was 240 g / L, nickel chloride concentration was 20 g / L, boric acid concentration was 8 g / L, sodium sulfate concentration was 20 g / L, and sodium dodecyl sulfate concentration was 5 g / L.

[0050] Step 3, preparing an iridium-tantalum solution: dissolving chloroiridic acid and tantalum ethoxide in n-butanol solution in turn, controlling the mass ratio of iridium-tantalum ions in the solution to be 6:4, and the total metal ion concentration of the iridium-tantalum solution to be 0.5 mol·L -1 .

[0051] Step 4, coating and sintering: Use a brush to evenly coat the iridium-tantalum solution prepared in step 3 on the surface of the nickel intermediate layer, place it in an oven for drying, and place the dried titanium alloy in a muffle furnace at 420°C for sintering for 25 minutes; repeat the above coating and sintering steps 12 times, and place it in a muffle furnace at 550°C for the last time for insulation for 2 hours to obtain the iridium-tantalum active coating.

[0052] Depend on Figure 1 It can be seen that Ti / IrO is prepared before nickel electroplating 2 -Ta 2 O 5 The anode surface morphology is mainly composed of flat areas, crack defects and IrO 2Cluster composition; Preparation of Ti / IrO after nickel electroplating 2 -Ta 2 O 5 Anode surface IrO 2 The amount of crystal cluster precipitation is small and the grains are relatively small, which is beneficial to increase the number of active sites for electrocatalytic reactions and improve electrocatalytic performance.

[0053] Figure 2 Preparation of Ti / IrO before and after nickel electroplating 2 -Ta 2 O 5 The CV curve of the anode shows that the electrode does not undergo oxygen evolution reaction in the potential range of 0.2V to 1.2V, and the current generated is the double-layer charging current of the electrode. At this time, the integral area of ​​the CV curve can reflect the number of active sites on the electrode surface. 2 -Ta 2 O 5 The integral area of ​​the CV curve of the anode is larger, and the electrocatalytic activity increases accordingly. The nickel intermediate layer enhances the conductivity of the coating. Under the action of the electric field, Cu 2+ Uniformly enrich, reduce and precipitate copper.

[0054] Depend on Figure 3 It can be seen that Ti / IrO is prepared before nickel electroplating 2 -Ta 2 O 5 The enhanced life of the anode is 552h, and the Ti / IrO 2 -Ta 2 O 5 The anode strengthening life is 792h, which significantly improves the electrolysis durability of the titanium anode in sulfuric acid solution.

Claims

1. A method for preparing a high-conductivity intermediate layer copper foil anode, characterized in that: The following steps are involved: Step 1, titanium alloy pretreatment: the pretreatment includes sandblasting, acid etching, cleaning, and drying; Step 2, electroplating nickel: using the titanium alloy pretreated in step 1 as an anode and the titanium plate as a cathode in an electroplating solution for electroplating deposition to prepare a nickel intermediate layer; the electroplating solution comprises: nickel sulfate, nickel chloride, boric acid, sodium sulfate, and sodium dodecyl sulfate; Step 3, preparing an iridium-tantalum solution: dissolving an iridium source and a tantalum source in an organic solvent; Step 4, coating and sintering: coating the iridium-tantalum solution prepared in step 3 on the surface of the nickel intermediate layer, drying and sintering and heat preservation, repeating for several times to obtain the iridium-tantalum active coating.

2. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 1, characterized in that: The concentrations of the components in the electroplating solution of step 2 are: nickel sulfate concentration is 120-240 g / L, nickel chloride concentration is 6-20 g / L, boric acid concentration is 3-8 g / L, sodium sulfate concentration is 10-20 g / L, and sodium dodecyl sulfate concentration is 1-5 g / L.

3. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 1, characterized in that: The current density during electroplating in step 2 is 0.5A / dm 2 -2A / dm 2 , the electroplating time is 10min-60min.

4. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 1, characterized in that: The preparation method of the iridium-tantalum solution in step 3 is specifically as follows: chloroiridic acid and tantalum ethoxide are dissolved in n-butanol solution in sequence.

5. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 4, characterized in that: The mass of iridium ions in the iridium-tantalum solution accounts for 60%-80% of the mass of total metal ions, the mass of tantalum ions accounts for 20%-40% of the mass of total metal ions, and the total metal ion concentration of the solution is 0.2-0.5 mol·L -1 .

6. The method for preparing a highly conductive intermediate layer copper foil anode according to claim 1, characterized in that: The specific operation of the coating and sintering in step 4 is as follows: drying the titanium alloy coated with the iridium-tantalum solution; placing the dried titanium alloy in a muffle furnace at 420° C. and sintering for 25 minutes; repeating the above coating and sintering steps 12 times, and placing the last time in a muffle furnace at 550° C. and keeping warm for 2 hours, to obtain the iridium-tantalum active coating.

7. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 1, characterized in that: The sandblasting sand mold in step 1 is any one of brown corundum, white corundum and steel sand.

8. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 7, characterized in that: After the sandblasting, the surface roughness of the titanium alloy is 6 μm<Ra<9 μm.

9. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 1, characterized in that: The acid etching is to place the sandblasted titanium alloy in a slightly boiling 15%-20% oxalic acid solution for etching for 2-5 hours.

10. The method for preparing a high-conductivity intermediate layer copper foil anode according to claim 1, characterized in that: The cleaning and drying are as follows: the titanium alloy after acid etching is rinsed with deionized water for 10 minutes and then dried.

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