A carbon-coated aluminum foil current collector for aqueous zinc ion batteries and a preparation method thereof

Abstract

The present invention discloses a carbon-coated aluminum foil current collector for aqueous zinc-ion batteries and a preparation method thereof. The invention relates to the field of current collectors and comprises an aluminum foil sheet and a carbon-coated layer coated on the aluminum foil sheet. The carbon-coated layer comprises the following raw materials in parts by weight: 10-20 parts of carbon powder; 2-6 parts of a dispersant; 30-60 parts of a solvent; and 10-20 parts of a pressure-sensitive adhesive. The carbon powder comprises acetylene black, carbon nanotubes, and graphite in a weight ratio of (0.33-0.47):1:(0.53-0.67). The present invention has the effect of improving the corrosion resistance of the current collector.

Description

Technical Field

[0001] The present invention relates to the field of current collectors, and in particular to a carbon-coated aluminum foil current collector for aqueous zinc ion batteries and a preparation method thereof. Background Art

[0002] In common battery types, such as lithium-ion batteries and lead-acid batteries, the commonly used current collector materials are the following: copper foil, aluminum foil, stainless steel mesh, and conductive polymers.

[0003] Aqueous zinc-ion battery is a new type of rechargeable battery technology. The current collector in the battery is a conductive material used to collect and distribute current; it is located between the positive and negative electrodes, ensuring the smooth transmission and balance of current.

[0004] However, zinc ions easily react chemically with aluminum foil to form a galvanic cell, which easily causes aluminum leakage on the surface of the current collector. Therefore, improving the corrosion resistance of the current collector and resisting the chemical reactions in the battery become important problems to be solved. Summary of the Invention

[0005] In order to improve the corrosion resistance of the current collector, the present application provides a carbon-coated aluminum foil current collector for an aqueous zinc ion battery and a preparation method thereof.

[0006] In the first aspect, the present application provides a carbon-coated aluminum foil current collector for an aqueous zinc ion battery using the following technical solution: a carbon-coated aluminum foil current collector for an aqueous zinc ion battery, comprising an aluminum foil and a carbon-coated layer coated on the aluminum foil, wherein the carbon-coated layer is made of the following raw materials in parts by weight: 10-20 parts of carbon powder; 2-6 parts of dispersant; 30-60 parts of solvent; and 10-20 parts of pressure-sensitive adhesive; the carbon powder comprises acetylene black, carbon nanotubes, and graphite, and the weight ratio of the acetylene black, carbon nanotubes, and graphite is (0.33-0.47):1:(0.53-0.67).

[0007] By adopting the above-mentioned technical solution, the present application improves the electrical conductivity of the aluminum foil by coating a carbon coating layer on the surface of the aluminum foil, effectively collecting and distributing the current from the positive and negative electrodes of the battery to the entire battery system, reducing resistance and improving the power output of the battery; the carbon coating layer is combined with carbon powder, pressure-sensitive adhesive, solvent and dispersant to make the carbon coating layer have a stable conductive interface, thereby preventing the aluminum foil from reacting with the electrolyte in the battery, reducing the internal resistance of the battery, and thus improving the cycle life and stability of the battery; at the same time, the carbon-containing material in the carbon powder has a strong corrosion resistance effect, which can effectively avoid the occurrence of electrochemical corrosion and improve the corrosion resistance of the current collector.

[0008] By adopting the above technical solution, the carbon nanotubes are modified carbon nanotubes; the preparation method of the modified carbon nanotubes is: 10-20 parts by weight of carbon nanotubes, 5-15 parts by weight of tannic acid and 20-40 parts by weight of water are stirred and mixed, and then ultrasonicated, and then 5-15 parts by weight of silane coupling agent and 10-20 parts by weight of nano-silica are added, mixed and stirred, centrifuged and then dried to obtain the modified carbon nanotubes.

[0009] By adopting the above technical solution, the present application uses silane coupling agent and nano-silica to modify nano-carbon tubes, so that the two fillers interact with each other to form chemical bonds, thereby improving the dispersibility of carbon powder in the components, increasing the adhesion time of active substances on the current collector, and thus improving the conductive properties of the current collector.

[0010] Preferably, the weight ratio of the carbon nanotubes, the silane coupling agent and the nano-silicon dioxide is (1.6-1.8):1:(1.2-1.4).

[0011] By adopting the above technical solution, when the carbon nanotubes, silane coupling agent and nano-silica are in a specific weight ratio, the three work together to make it difficult for the silane coupling agent to form a bonded coating on the surface of the nano-silica, thereby making it difficult for the nano-silica to agglomerate, further improving the dispersion performance of the components, making the carbon coating layer have a stable conductive interface, and improving the electrical conductivity of the carbon nanotubes to the carbon coating layer; at the same time, it can resist chemical reactions in the battery and electrolyte erosion, thereby extending the service life of the battery.

[0012] Preferably, the pressure-sensitive adhesive comprises one or more of acrylic resin, silicone resin and fluororesin.

[0013] By adopting the above technical solution, acrylic resin has good adhesion, which can form a strong bond between the current collector and other components, increase the strength of the current collector, and protect the current collector from chemical corrosion; silicone resin can form a good sealing and adhesion effect when in contact with the current collector, which helps to prevent water vapor, dust and other impurities from entering the current collector, thereby improving the reliability and stability of electronic components; fluororesin can provide good chemical corrosion resistance, help protect the current collector from erosion by chemical substances, and extend the service life of the current collector.

[0014] Preferably, the weight ratio of the silicone resin to the fluororesin is (5-7): (8-10).

[0015] By adopting the above technical solution, when the silicone resin and the fluororesin are in a specific weight ratio, the silicone resin can maintain stable adhesion at higher temperatures, and the fluororesin can maintain stable performance in harsh environments. The two work together to enable the current collector to adapt to different application environments and requirements, extend the service life of the current collector, and further improve the stability and reliability of the current collector; make the corrosion resistance of the current collector better, and at the same time increase the strength of the current collector and improve the tensile performance of the current collector.

[0016] Preferably, the solvent is one of ethyl acetate, butyl acetate and butanone.

[0017] By adopting the above technical solution and selecting the above organic solvent as the solvent of the current collector, other components in the current collector can be dissolved to form a uniform solution and dispersion system, thereby improving the coating performance of the current collector and making it easier to coat the carbon coating layer on the aluminum foil.

[0018] Preferably, the weight ratio of the carbon powder, the pressure-sensitive adhesive and the solvent is 1:(0.8-1):(3.2-3.8).

[0019] By adopting the above technical solution, when the carbon powder, pressure-sensitive adhesive and solvent are in a specific weight ratio, the three work together to help improve the corrosion resistance of the current collector and further improve the conductive performance of the current collector.

[0020] Preferably, the carbon coating layer has a thickness of 1-3 μm.

[0021] By adopting the above technical solution, the thickness of the carbon coating layer is controlled so that the carbon coating layer can be evenly coated on the aluminum foil, further improving the density of the carbon coating layer on the aluminum foil.

[0022] In a second aspect, the present application provides a method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery using the following technical solution:

[0023] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery comprises the following steps: mixing and stirring carbon powder, a dispersant and a solvent, then adding a pressure-sensitive adhesive, mixing and stirring to obtain a mixed liquid; immersing aluminum foil in the mixed liquid, and drying to obtain the carbon-coated aluminum foil current collector.

[0024] By adopting the above technical solution, the preparation method of the present application can save process materials, reduce process steps, and make the prepared carbon-coated aluminum foil current collector have strong conductivity and excellent corrosion resistance.

[0025] Preferably, the drying temperature is 90-140°C.

[0026] By adopting the above technical solution and controlling the drying temperature of the aluminum foil after immersion, the carbon coating layer can be better adhered to the aluminum foil, reducing the porosity of the aluminum foil, thereby enhancing the conductive performance of the aluminum foil.

[0027] In summary, this application has the following beneficial technical effects:

[0028] 1. This application improves the electrical conductivity of the aluminum foil by coating the surface of the aluminum foil with a carbon coating layer, effectively collecting and distributing current from the positive and negative electrodes of the battery to the entire battery system, reducing resistance and increasing the battery's power output. The carbon coating layer is made by combining carbon powder, pressure-sensitive adhesive, solvent, and dispersant to provide a stable conductive interface, thereby preventing the aluminum foil from reacting with the electrolyte in the battery, reducing the battery's internal resistance, and thus improving the battery's cycle life and stability. At the same time, the carbon-containing material in the carbon powder has a strong corrosion resistance, which can effectively prevent the occurrence of electrochemical corrosion and improve the corrosion resistance of the current collector.

[0029] 2. When the carbon nanotubes, silane coupling agent and nano-silica are in a specific weight ratio, the three work together to make it difficult for the silane coupling agent to form a bonded coating on the surface of the nano-silica, thereby making it difficult for the nano-silica to agglomerate, further improving the dispersion performance of the components, making the carbon coating layer have a stable conductive interface, and improving the electrical conductivity of the carbon nanotubes to the carbon coating layer; at the same time, it can resist chemical reactions in the battery and the erosion of the electrolyte, thereby extending the service life of the battery. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the following examples and comparative examples.

[0031] Example

[0032] Example 1

[0033] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery comprises the following steps:

[0034] 10 g of carbon powder, 2 g of dispersant and 30 g of solvent were mixed and stirred at a speed of 600 r / min for 10 minutes, and then 10 g of pressure-sensitive adhesive was added and mixed and stirred at 1000 r / min for 30 minutes to obtain a mixed liquid; aluminum foil was immersed in the mixed liquid and dried at a temperature of 90°C for 30 minutes to obtain a carbon-coated aluminum foil current collector.

[0035] The carbon powder is 2g acetylene black, 5g carbon nanotubes and 3g graphite; the dispersant is polyvinyl alcohol, selected from Kuraray RS-1717; the solvent is ethyl acetate; the pressure-sensitive adhesive is acrylic resin, selected from Xinlian Chemical, with a molecular weight of 18,000.

[0036] Example 2

[0037] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery comprises the following steps:

[0038] 20 g of carbon powder, 6 g of dispersant and 60 g of solvent were mixed and stirred at a speed of 600 r / min for 10 minutes, and then 20 g of pressure-sensitive adhesive was added and mixed and stirred at 1000 r / min for 30 minutes to obtain a mixed liquid; aluminum foil was immersed in the mixed liquid and dried at a temperature of 140°C for 30 minutes to obtain a carbon-coated aluminum foil current collector.

[0039] The carbon powder is 4g acetylene black, 10g carbon nanotubes and 6g graphite; the dispersant is polyvinyl alcohol, selected as Kuraray RS-1717; the solvent is butanone; the pressure-sensitive adhesive is acrylic resin, selected from Daikin USA, brand NA101.

[0040] Example 3

[0041] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery comprises the following steps:

[0042] 15 g of carbon powder, 4 g of dispersant and 45 g of solvent were mixed and stirred at a speed of 600 r / min for 10 minutes, and then 15 g of pressure-sensitive adhesive was added and mixed and stirred at 1000 r / min for 30 minutes to obtain a mixed liquid; aluminum foil was immersed in the mixed liquid and dried at a temperature of 90°C for 30 minutes to obtain a carbon-coated aluminum foil current collector.

[0043] The carbon powder is 3g acetylene black, 7.5g carbon nanotubes and 4.5g graphite; the dispersant is polyvinyl alcohol, selected from Kuraray RS-1717; the solvent is butyl acetate; the pressure-sensitive adhesive is methyl silicone resin, selected from Jibin Chemical, with a molecular weight of 5000.

[0044] Example 4

[0045] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery is different from that of Example 3 in that the carbon powder comprises 3.5 g of acetylene black, 7.5 g of carbon nanotubes, and 4 g of graphite.

[0046] Example 5

[0047] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery is different from that of Example 3 in that the carbon powder comprises 2.5 g of acetylene black, 7.5 g of carbon nanotubes, and 5 g of graphite.

[0048] Example 6

[0049] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery differs from Example 3 in that an equal amount of the carbon nanotubes in Example 4 is replaced with modified carbon nanotubes. The modified carbon nanotubes are prepared by stirring 10 g of carbon nanotubes, 5 g of tannic acid, and 20 g of water at a rotation speed of 800 r / min for 10 minutes, ultrasonicating for 30 minutes, then adding 5 g of a silane coupling agent KH570 and 10 g of nano-silica, stirring for 10 minutes, centrifuging, and transferring to an oven for drying at 100° C. for 6 hours to obtain the modified carbon nanotubes.

[0050] Example 7

[0051] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery differs from Example 3 in that an equal amount of the carbon nanotubes in Example 4 is replaced with modified carbon nanotubes. The modified carbon nanotubes are prepared by stirring 20 g of carbon nanotubes, 15 g of tannic acid, and 40 g of water at a rotation speed of 800 r / min for 10 minutes, ultrasonicating for 30 minutes, then adding 15 g of a silane coupling agent KH570 and 20 g of nano-silica, stirring for 10 minutes, centrifuging, and transferring to an oven for drying at 100° C. for 6 hours to obtain the modified carbon nanotubes.

[0052] Example 8

[0053] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery, which differs from Example 6 in that: the input amount of carbon nanotubes is 16 g, the input amount of silane coupling agent KH570 is 10 g, and the input amount of nano-silicon dioxide is 12 g.

[0054] Example 9

[0055] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery, which differs from Example 6 in that: the input amount of carbon nanotubes is 18 g, the input amount of silane coupling agent KH570 is 10 g, and the input amount of nano-silica is 14 g.

[0056] Example 10

[0057] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery, which differs from Example 8 in that the pressure-sensitive adhesive is 5g of silicone resin and 10g of fluororesin.

[0058] Example 11

[0059] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery, which differs from Example 8 in that the pressure-sensitive adhesive comprises 7 g of silicone resin and 8 g of fluororesin.

[0060] Example 12

[0061] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery is different from that of Example 8 in that: the input amount of carbon powder is 15 g, the input amount of pressure-sensitive adhesive is 12 g, and the input amount of solvent is 48 g.

[0062] Example 13

[0063] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery is different from that of Example 8 in that: the input amount of carbon powder is 15 g, the input amount of pressure-sensitive adhesive is 15 g, and the input amount of solvent is 57 g.

[0064] Comparative Example

[0065] Comparative Example 1

[0066] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery differs from Example 3 in that equal amounts of acetylene black and graphite are replaced with carbon nanotubes.

[0067] Comparative Example 2

[0068] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery differs from that of Example 3 in that an equal amount of acetylene black is replaced with graphite.

[0069] Comparative Example 3

[0070] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery is different from that of Example 3 in that the carbon powder comprises 5 g of acetylene black, 5 g of carbon nanotubes, and 5 g of graphite.

[0071] Comparative Example 4

[0072] A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery differs from that of Example 3 in that no carbon powder is added.

[0073] Performance testing:

[0074] Corrosion resistance: The carbon-coated aluminum foil current collectors prepared in Examples 1-13 and Comparative Examples 1-4 were immersed in a 2 mol / L zinc sulfate mixed solution. After 60 days, the current collectors were taken out and cleaned. No aluminum leakage points were found, indicating that the corrosion resistance was good.

[0075] Conductive properties: The ohmic internal resistance of the carbon-coated aluminum foil current collectors prepared in Examples 1-13 and Comparative Examples 1-4 was measured and calculated using a resistance meter with reference to IEC 62631-1-1.

[0076] Tensile properties: The tensile strength of the carbon-coated aluminum foil current collectors prepared in Examples 1-13 and Comparative Examples 1-4 was tested according to the method of GB / T16865-1997.

[0077]

[0078]

[0079] According to the data comparison of Examples 1-5 and Comparative Examples 1-4, the present application improves the electrical conductivity of the aluminum foil by coating a carbon coating layer on the surface of the aluminum foil, effectively collects and distributes the current from the positive and negative electrodes of the battery to the entire battery system, reduces resistance, and improves the power output of the battery; the carbon coating layer is combined with carbon powder, pressure-sensitive adhesive, solvent and dispersant to make the carbon coating layer have a stable conductive interface, thereby preventing the aluminum foil from reacting with the electrolyte in the battery, reducing the internal resistance of the battery, and thus improving the cycle life and stability of the battery; at the same time, the carbon-containing material with strong corrosion resistance in the carbon powder can effectively avoid the occurrence of electrochemical corrosion and improve the corrosion resistance of the current collector.

[0080] According to the data comparison of Example 3 and Examples 6-7, the present application uses silane coupling agent and nano-silicon dioxide to modify the nano-carbon tubes, so that the two fillers interact with each other to form chemical bonds, thereby improving the dispersibility of carbon powder in the components, increasing the adhesion time of the active substance on the current collector, and further improving the conductive properties of the current collector.

[0081] According to the data comparison of Example 6 and Examples 8-9, it can be seen that when the carbon nanotubes, the silane coupling agent and the nano-silica are in a specific weight ratio, the three work together to make it difficult for the silane coupling agent to form a bonded coating on the surface of the nano-silica, thereby making it difficult for the nano-silica to agglomerate, further improving the dispersion performance of the components, making the carbon coating layer have a stable conductive interface, and improving the electrical conductivity of the carbon nanotubes to the carbon coating layer; at the same time, it can resist chemical reactions in the battery and erosion by the electrolyte, thereby extending the service life of the battery.

[0082] According to the data comparison of Example 8 and Examples 10-11, it can be seen that when the silicone resin and the fluororesin are in a specific weight ratio, the silicone resin can maintain stable adhesion at higher temperatures, and the fluororesin can maintain stable performance in harsh environments. The two work together to enable the current collector to adapt to different application environments and requirements, extend the service life of the current collector, and further improve the stability and reliability of the current collector; make the corrosion resistance of the current collector better, and at the same time increase the strength of the current collector and improve the tensile performance of the current collector.

[0083] According to the data comparison of Example 8 and Examples 12-13, when the carbon powder, pressure-sensitive adhesive and solvent are in a specific weight ratio, the three work together to help improve the corrosion resistance of the current collector and further improve the conductive performance of the current collector.

[0084] The specific embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the embodiments as needed, but as long as they are within the scope of the claims of the present application, they are protected by patent law.

Claims

1. A carbon-coated aluminum foil current collector for an aqueous zinc ion battery, characterized in that: The method comprises an aluminum foil and a carbon coating layer coated on the aluminum foil, wherein the carbon coating layer is made of the following raw materials in parts by weight: 10-20 parts of carbon powder; 2-6 parts of dispersant; 30-60 parts of solvent; 10-20 parts of pressure-sensitive adhesive; the carbon powder includes acetylene black, carbon nanotubes and graphite, and the weight ratio of acetylene black, carbon nanotubes and graphite is (0.33-0.47):1:(0.53-0.67); The carbon nanotubes are modified carbon nanotubes; the modified carbon nanotubes are prepared by stirring and mixing 10-20 parts by weight of carbon nanotubes, 5-15 parts by weight of tannic acid, and 20-40 parts by weight of water, followed by ultrasonication, and then adding 5-15 parts by weight of a silane coupling agent and 10-20 parts by weight of nano-silicon dioxide, stirring the mixture, centrifuging, and then drying to obtain the modified carbon nanotubes; The pressure-sensitive adhesive includes one or more of acrylic resin, silicone resin and fluororesin.

2. The carbon-coated aluminum foil current collector for aqueous zinc ion batteries according to claim 1, wherein: The weight ratio of the carbon nanotubes, the silane coupling agent and the nano-silicon dioxide is (1.6-1.8):1:(1.2-1.4).

3. The carbon-coated aluminum foil current collector for aqueous zinc ion batteries according to claim 1, wherein: The weight ratio of the silicone resin to the fluororesin is (5-7): (8-10).

4. The carbon-coated aluminum foil current collector for aqueous zinc ion batteries according to claim 1, wherein: The solvent is one of ethyl acetate, butyl acetate and butanone.

5. The carbon-coated aluminum foil current collector for aqueous zinc ion batteries according to claim 1, wherein: The weight ratio of the carbon powder, the pressure-sensitive adhesive and the solvent is 1: (0.8-1): (3.2-3.8).

6. The carbon-coated aluminum foil current collector for aqueous zinc ion batteries according to claim 1, wherein: The thickness of the carbon coating layer is 1-3 μm.

7. A method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery, characterized in that: The method for preparing the carbon-coated aluminum foil current collector for an aqueous zinc ion battery according to any one of claims 1 to 6 comprises the following steps: mixing and stirring carbon powder, a dispersant and a solvent, then adding a pressure-sensitive adhesive, mixing and stirring to obtain a mixed liquid; immersing aluminum foil in the mixed liquid, and drying to obtain the carbon-coated aluminum foil current collector.

8. The method for preparing a carbon-coated aluminum foil current collector for an aqueous zinc ion battery according to claim 7, wherein: The drying temperature is 90-140°C.

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