Acid and alkali corrosion resistant composite current collector film and preparation method thereof

Abstract

This invention provides an acid and alkali resistant composite current collector membrane and its preparation method. The composite current collector membrane is a thin-film current collector composed of carbon material, a carbon film, and a gold source. In its composite structure, the gold source is distributed on the carbon material film and within the carbon material bulk phase, forming a close contact with the carbon material, thereby achieving good conductivity. This invention also provides a method for preparing this composite current collector membrane. The acid and alkali resistant composite current collector membrane produced by this method can be applied to long-life and fast-charging lead-acid batteries and other rechargeable, high-safety batteries using aqueous solutions.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to an acid and alkali resistant thin-film current collector and its preparation method. Background Technology

[0002] With the advancement of electrification, lithium batteries have seen significant development in the last two decades. They boast high energy density, high charge / discharge efficiency, and long lifespan. However, their drawbacks include the use of organic solvents as electrolytes, which are flammable substances. Furthermore, the negative electrode of a lithium battery after charging contains highly flammable and explosive lithium compounds, such as lithium carbide, frequently leading to accidents during use. Therefore, the safety requirements for rechargeable batteries are increasingly stringent. Traditional lead-acid batteries are a safe type of rechargeable battery, but their low energy density and short cycle life fail to meet market demands. To research and develop safe, high-performance rechargeable batteries, especially novel batteries using aqueous solutions as electrolytes, it is necessary to research and manufacture current collectors that can withstand acid and alkali corrosion in aqueous solutions. Traditional lead-acid batteries use lead plates as current collectors. The disadvantages of lead plate current collectors are that they must have a certain thickness; if too thick, the weight is increased, resulting in lower overall battery energy density; if too thin, they are easily oxidized into lead sulfate during charging, becoming non-conductive and losing their function as current collectors.

[0003] Therefore, the most basic requirement for current collectors is that they must be stable during charging and discharging, without undergoing electrochemical reactions. If carbon materials can be combined with a metal that is resistant to acid and alkali corrosion, it may be possible to create a current collector that can operate in acid and alkali aqueous solutions, i.e., a water-based current collector. Using such a current collector, long-life and fast-charging lead-acid batteries and other rechargeable, high-safety batteries in aqueous solution systems can be manufactured. Summary of the Invention

[0004] To address the above problems, this invention provides an acid and alkali resistant composite current collector membrane and its preparation method.

[0005] The objective of this invention is achieved through the following technical solution: This invention provides a composite current collector membrane resistant to acid and alkali corrosion. The composite current collector membrane is a thin film current collector composed of carbon material, carbon film and gold source. In its composite structure, the gold source is distributed on the carbon material film and in the carbon material bulk phase, forming a close contact with the carbon material, thereby achieving good conductivity.

[0006] Preferably, the carbon material is selected from graphite, carbon fiber, carbon materials that can form good electrical conductivity through thermal decomposition, and one or more of these carbon materials combined with polymer materials to form conductive carbon materials.

[0007] Preferably, the polymer material is one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylate, phenolic resin, or polyacrylonitrile.

[0008] To solve the above-mentioned technical problems, the present invention also provides a method for preparing the above-mentioned acid and alkali resistant composite current collector membrane, comprising the following steps: S1: The gold source and carbon film are combined to form a composite gold carbon film; S2: A mixed slurry made of carbon material, polymer material binder, and dispersing solvent is coated onto the carbon film of the composite gold to obtain a pre-formed film; S3: The pre-made membrane is subjected to high-temperature reduction heat treatment to obtain a composite current collector membrane resistant to acid and alkali corrosion.

[0009] Preferably, the gold source in step S1 is selected from gold chloride, gold powder, gold wire, or gold mesh.

[0010] Preferably, in step S1, a gold source is deposited on a carbon film using vacuum magnetron sputtering to obtain a composite gold carbon film.

[0011] Preferably, in step S1, a composite gold carbon film is obtained by depositing a gold source onto a carbon film using chemical vapor deposition.

[0012] Preferably, in step S1, a composite gold carbon film is obtained by depositing the gold source onto the carbon film using a vacuum thermal evaporation method.

[0013] Preferably, in step S1, a carbon film is prepared by immersing a solution of gold chloride in it to obtain a composite gold carbon film.

[0014] Preferably, in step S1, a composite gold carbon film is obtained by spraying or directly applying ink to a carbon film by preparing a mixed solution of gold chloride and polymer material.

[0015] Preferably, the carbon film in step S1 is selected from carbon fiber film, carbon paper, or carbon material film.

[0016] Preferably, the polymeric material in step S1 is one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylate, phenolic resin, or polyacrylonitrile.

[0017] Preferably, the high-temperature reduction heat treatment in step S3 is a carbonization treatment at a temperature of 600-950°C in an inert atmosphere.

[0018] Compared with existing technologies, the acid and alkali resistant composite current collector membrane and its preparation method provided by this invention have the following beneficial effects: First, the acid and alkali resistant composite current collector membrane is a thin film composite made of metallic gold and carbon materials. The metallic gold is distributed in various ways on the carbon material film and in the carbon material bulk phase, forming a close contact with the carbon material, thus forming a composite film with good conductivity. Second, the acid and alkali resistant composite current collector membrane is a current collector that can work in acid and alkali aqueous solutions, that is, a water-based current collector. Using such a current collector, long-life and fast-charging lead-acid batteries and other rechargeable high-safety batteries in aqueous solution systems can be manufactured. Detailed Implementation

[0019] The following detailed description, in conjunction with specific embodiments, further illustrates the method for preparing the carbon material and gold composite thin film current collector of the present invention. Example 1

[0020] AuCl3·HCl·4H2O (0.5000 g), graphite powder (average particle size 10 to 20 micrometers, 50.000 g), phenolic resin (8.00 g), and industrial ethanol (60 g) were mixed and stirred into a slurry. The slurry was then coated onto a 20x40 cm carbon fiber membrane (100 micrometers thick) to obtain a sample membrane with a coating thickness of 30 micrometers. The sample membrane was dried in a tube furnace at 60°C with N2 for one hour. Then, the temperature was increased to 900°C at a rate of 5°C per minute and held for 30 minutes. Finally, the temperature was allowed to cool naturally to room temperature to obtain a thin film current collector composed of carbon material and metallic gold. Example 2

[0021] 0.2000 g of nano-gold powder (1-100 nm), 8.000 g of polyvinylpyrrolidone (binder), and 100 g of water were mixed to form a slurry. The slurry was coated onto a 20 x 40 cm carbon fiber membrane (100 μm thick) to obtain a sample membrane with a coating thickness of 30 μm. The sample membrane was dried in an oven at 80°C for one hour, then transferred to a tube furnace under nitrogen atmosphere, heated to 600°C at a rate of 5°C per minute, and held for 30 minutes. It was then allowed to cool naturally to room temperature to obtain a thin film current collector composed of carbon material and metallic gold. Example 3

[0022] Dissolve 0.1000 g of AuCl3·HCl·4H2O in a 60 g beaker containing 250 ml of industrial ethanol. Place a 3 x 3 cm piece of carbon paper (400 μm thick) in the beaker. Dissolve 0.500 g of NaBH4 in a beaker containing 50 g of industrial ethanol to obtain a solution. Slowly add the NaBH4 ethanol solution to the gold solution while continuously shaking the beaker containing gold and carbon paper. Continue shaking and react for 2 hours. Remove the gold-plated carbon paper to obtain the current collector. Example 4

[0023] To reinforce the gold plating layer on the current collector obtained in Example 3, the current collector obtained in Example 3 was immersed in an ethanol solution containing 5% phenolic resin for 10 minutes. The current collector was then removed and placed in a tube furnace purged with nitrogen at 80°C for 20 minutes. Then, the temperature was increased to 950°C at a rate of 5°C per minute and held for 30 minutes. Finally, the temperature was allowed to cool naturally to room temperature to obtain a thin film current collector composed of carbon material and metallic gold.

[0024] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. Those skilled in the art can readily conceive of making appropriate adjustments and recombinations to the embodiments according to actual needs, based on the disclosure in this specification, without departing from the spirit of this application. The scope of protection of this application is defined by the claims of this application.

Claims

1. A composite current collector membrane resistant to acid and alkali corrosion, characterized in that: The composite current collector membrane is a thin film current collector composed of carbon material, carbon film and gold source. In its composite structure, the gold source is distributed on the carbon material film and in the carbon material bulk phase, forming a close contact with the carbon material.

2. The acid and alkali resistant composite current collector membrane according to claim 1, characterized in that: The carbon material is selected from graphite, carbon fiber, carbon materials that can be thermally decomposed to form conductive materials, and conductive carbon materials formed by combining these carbon materials with polymer materials, or one or more of these materials.

3. The acid and alkali resistant composite current collector membrane according to claim 1, characterized in that: The polymer material is one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylate, phenolic resin, or polyacrylonitrile.

4. A method for preparing an acid and alkali resistant composite current collector membrane, used to prepare the composite current collector membrane as described in any one of claims 1-3, characterized in that: Includes the following steps: S1: The gold source and carbon film are combined to form a composite gold carbon film; S2: A mixed slurry made of carbon material, polymer material binder, and dispersing solvent is coated onto the carbon film of the composite gold to obtain a pre-formed film; S3: The pre-made membrane is subjected to high-temperature reduction heat treatment to obtain a composite current collector membrane resistant to acid and alkali corrosion.

5. The method for preparing an acid and alkali resistant composite current collector membrane according to claim 4, characterized in that: The gold source mentioned in step S1 is selected from gold chloride, gold powder, gold wire or gold mesh.

6. The method for preparing an acid and alkali resistant composite current collector membrane according to claim 5, characterized in that: In step S1, gold chloride and polymer materials are mixed to form a solution, which is then sprayed or directly applied as ink to a carbon film to obtain a composite gold carbon film.

7. The method for preparing an acid and alkali resistant composite current collector membrane according to claim 4, characterized in that: In step S1, a composite gold carbon film is obtained by depositing a gold source onto a carbon film using one of the following methods: vacuum magnetron sputtering, chemical vapor deposition, or vacuum thermal evaporation.

8. The method for preparing an acid and alkali resistant composite current collector membrane according to claim 4, characterized in that: The carbon film mentioned in step S1 is selected from carbon fiber film, carbon paper or carbon material film.

9. The method for preparing an acid and alkali resistant composite current collector membrane according to claim 4, characterized in that: The polymeric material mentioned in step S2 is one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylate, phenolic resin, or polyacrylonitrile.

10. The method for preparing an acid and alkali resistant composite current collector membrane according to claim 4, characterized in that: The high-temperature reduction heat treatment described in step S3 is a carbonization treatment at a temperature of 600-950°C in an inert atmosphere.