A DNA-coated current collector, its preparation method and application

Abstract

This invention relates to a DNA-coated current collector, its preparation method, and its application, belonging to the field of lithium battery technology. The method for preparing the DNA-coated current collector provided by this invention includes the following steps: (1) taking aloe vera gel tissue, adding it to SDS buffer for lysis to obtain a lysate, then adding NaCl solution for treatment, and filtering to obtain a filtrate; (2) adding an organic solvent to the filtrate for precipitation, separating the solid and liquid to obtain an active substance containing DNA, and preparing a solution containing DNA; (3) covering the surface of a silver foil with the DNA-containing solution, allowing it to stand, and then drying to form a coating layer, thus obtaining a DNA-coated current collector. This invention uses aloe vera-extracted DNA to coat a silver current collector, which has strong interfacial bonding and can effectively inhibit lithium dendrite growth, improve the cycle stability of lithium batteries, and enhance battery life.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a DNA-coated current collector, its preparation method, and its application. Background Technology

[0002] Traditional lithium batteries mostly use copper and aluminum current collectors. Copper current collectors are used in the negative electrode, which are low in cost and have good conductivity, but they have problems such as heavy weight and easy oxidation; aluminum current collectors are used in the positive electrode, which are lightweight and resistant to high voltage, but they have poor flexibility and are easy to corrode.

[0003] To address the problems of traditional copper-aluminum current collectors, researchers have proposed using composite current collectors, such as metal-polymer-metal sandwich structures (aluminum-PET-aluminum), which can improve safety and energy density, but at a higher cost. Using lightweight, highly conductive nanomaterials such as graphene and carbon nanotubes is beneficial for weight reduction, but it remains in the laboratory stage and faces challenges in cost and large-scale production. Making the current collector ultrathin, reducing the thickness of the copper / aluminum foil, can reduce weight and increase energy density, but places higher demands on manufacturing processes (such as rolling technology). Ag exhibits unique advantages in certain battery systems (such as lithium metal batteries) due to its excellent conductivity and chemical stability; however, the surface of a single Ag element is usually smooth and inert, resulting in weak bonding with active materials (such as sulfur, silicon, and metal oxide electrodes) or the electrolyte interface, making it prone to delamination. Although Ag has excellent conductivity, poor contact may exist at its interface with active materials, such as conversion or alloy electrode materials, or it may react with Li to form an insulating layer, leading to increased interfacial resistance and performance degradation. Furthermore, exposed smooth metal surfaces are prone to uneven ion deposition and dendrite growth.

[0004] To address the problems existing in current Ag current collectors, there is an urgent need for an optimization strategy that can improve the interface issues of Ag current collectors, enhance performance, and suppress dendrite growth. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a DNA-coated current collector, its preparation method, and its application. The DNA-coated current collector strategy provided by this invention can improve interfacial bonding, suppress lithium dendrite growth, and enhance battery cycle performance.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a current collector based on DNA coating, comprising the following steps:

[0008] (1) Take aloe vera gel tissue and add it to SDS buffer to lyse it, then add NaCl solution to treat it and filter to obtain filtrate;

[0009] (2) Add an organic solvent to the filtrate to precipitate, and separate the solid and liquid to obtain an active substance containing DNA, and prepare a solution containing DNA.

[0010] (3) The solution containing DNA is applied to the surface of the silver foil, and after standing, it is dried to form a coating layer, thereby obtaining the DNA-coated current collector.

[0011] This invention provides an optimized strategy for preparing current collectors by coating silver foil with extracted aloe vera DNA. First, aloe vera gel tissue is lysed using SDS (sodium dodecyl sulfate) buffer to release intracellular DNA and other components. Then, NaCl is added to remove polysaccharides via precipitation, yielding a filtrate containing aloe vera DNA. The DNA-containing active substances are then separated by precipitation to prepare a DNA-containing solution. This solution is then coated with silver foil and allowed to dry to obtain a DNA-coated current collector.

[0012] The raw material selected for extraction in this invention is aloe vera gel tissue. Aloe vera leaves comprise the epidermis, gel tissue, and mucus. The aloe vera gel tissue, also known as the mesophyll, is located inside the aloe vera leaf and is composed of irregularly shaped, large, thin-walled cells. The main source of DNA in this invention is thin-walled cells, whose cell walls contain less pectin. After cell lysis, impurities such as polysaccharides and proteins are significantly lower than those found in other sources of plant DNA (such as algal DNA) or animal DNA (such as salmon sperm DNA).

[0013] In contrast, DNA extracted from other plants is generally co-extracted with pectin and hemicellulose (such as cacti and algae), which may pose a risk of polysaccharide contamination blocking electrical conductivity. Even with increased NaCl precipitation cycles, residual polysaccharides will still carbonize at high temperatures (battery cycling), leading to increased interfacial resistance. Animal-derived DNA extraction (such as bovine thymus and salmon semen) requires strong proteinase K digestion to remove histones, but histone residues may still remain. These residues can decompose under high pressure, producing NH3, which poses a corrosion risk.

[0014] On the other hand, the present invention uses Ag current collectors, which are unique to Ag. + Dissolution activity can achieve phosphodiester bond (-PO2) with the extracted aloe DNA. - -) and nitrogen-containing base groups (-NH2, -NH-, =N-, etc.) form dynamic chemical bonds. This mechanism not only buffers charge and discharge stress but also induces homogeneous lithium deposition. Other current collectors are not suitable for the coating strategy of this invention, as they may lead to loss of bonding force, alloying / oxidative corrosion, or ion transport blockage, thereby affecting battery performance.

[0015] Meanwhile, the active substances obtained using the specific raw materials and extraction method of this invention have a molecular weight of aloe vera DNA of 20-50 kbp, while the molecular weight of extracted animal DNA is mostly <10 kbp. This invention obtains longer DNA molecular chains through extraction, which is more conducive to the interaction between the phosphodiester bonds and nitrogen-containing base groups in the DNA molecular chain and the trace amounts of Ag dissolved by the Ag current collector. + By combining these elements, a denser network structure is obtained, which is beneficial for achieving strong interfacial bonding of Ag current collectors.

[0016] The current collector prepared by the DNA-coated current collector preparation method of this invention can achieve strong interfacial bonding, induce homogeneous lithium deposition, reduce lithium dendrite growth, comprehensively improve the cycle stability of the battery, and enhance the battery's range.

[0017] Preferably, in step (1), the aloe vera gel tissue is first pretreated by washing away the mucus and then cutting and grinding it into a paste.

[0018] Preferably, in step (1), the reaction conditions for pyrolysis are: reacting at 55-65°C for 10-20 minutes, and mixing once every 4-6 minutes;

[0019] Preferably, in step (1), the NaCl solution is added under the following conditions: an ice bath for 8-12 minutes.

[0020] The ice-salt precipitation method was used, where NaCl at 0°C can bind to negatively charged pectin to accelerate precipitation, thereby removing polysaccharides through filtration.

[0021] Preferably, in step (1), the volume of the SDS buffer is 4-6 times the volume of the aloe vera gel tissue;

[0022] Preferably, in step (1), the mass-volume percentage of SDS in the SDS buffer is 1.5-2.5%.

[0023] More preferably, the SDS in the SDS buffer solution is 2% by volume.

[0024] The optimized SDS concentration can fully dissolve the cell membrane without disrupting the DNA phosphodiester backbone.

[0025] Preferably, in step (1), the volume of the NaCl solution is 5-15% of the volume of the pyrolysis solution;

[0026] Preferably, in step (1), the concentration of NaCl in the NaCl solution is 2.0-2.5 mol / L.

[0027] Preferably, in step (2), the organic solvent includes at least one of isopropanol and ethanol;

[0028] More preferably, the organic solvent is a pre-cooled organic solvent;

[0029] As a preferred option, isopropanol is selected as the organic solvent, and its volume is equal to that of the filtrate; ethanol is selected as the organic solvent, and its volume is twice that of the filtrate.

[0030] Preferably, in step (2), the precipitation temperature is -20 to 0°C, and the precipitation time is 20 to 30 minutes. Slow precipitation allows the DNA to maintain its extended long chain configuration and ensures that the molecular weight retention rate is >95%, resulting in DNA molecules with a longer chain length.

[0031] Preferably, in step (2), the solid-liquid separation specifically involves centrifuging at 11000-12000 rpm for 5-6 minutes to remove the supernatant;

[0032] Preferably, in step (2), after precipitation and solid-liquid separation, there are also washing and drying steps to obtain an active substance powder containing DNA, which is then prepared into a solution containing DNA.

[0033] After adding an organic solvent and precipitating at low temperature, DNA forms a white flocculent precipitate. The supernatant is removed by centrifugation to obtain a moist precipitate containing DNA active substances. Further washing removes salt and drying removes moisture to obtain DNA with higher purity.

[0034] More preferably, the washing is performed using a 70% ethanol aqueous solution, and the drying is performed by placing the product in a vacuum drying oven at 25°C for 24 hours.

[0035] Preferably, in step (3), the concentration of the active substance containing DNA in the DNA-containing solution is 1.5-2.5 mg / ml;

[0036] Preferably, in step (3), the silver foil is fully immersed in the DNA-containing solution prepared in step (2) to achieve coverage;

[0037] Preferably, in step (3), the settling time is 15-25 minutes.

[0038] Preferably, in step (3), the drying process involves placing the item in a vacuum drying oven at 25°C for 24 hours.

[0039] Preferably, in step (3), the thickness of the coating layer is 1.1-1.3 μm.

[0040] Secondly, the present invention provides a DNA-coated current collector prepared by the above-described method for preparing a DNA-coated current collector.

[0041] Preferably, the DNA-coated current collector comprises a silver foil substrate and a DNA layer covering at least one side of the silver foil substrate.

[0042] Thirdly, the present invention provides the application of the above-mentioned DNA-coated current collector in lithium batteries.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] This invention provides a method for preparing a current collector based on DNA coating. By employing a specific DNA extraction step, a three-in-one processing system of directional impurity removal, conformation protection, and zero-pollution residue is established. The extracted DNA is then coated onto silver foil to form a coating layer, thereby realizing the preparation of aloe vera DNA-coated silver current collector. The resulting DNA coating layer has strong interfacial bonding and can effectively inhibit lithium dendrite growth, thus comprehensively improving the performance of batteries. Attached Figure Description

[0045] Figure 1 (a) SEM image of the current collector surface in Comparative Example 1; (b) SEM image of the current collector surface based on DNA coating in Example 1; (c) SEM image of the current collector surface after lithium plating in Comparative Example 1; (d) SEM image of the current collector surface after lithium plating based on DNA coating in Example 1.

[0046] Figure 2 The graph shows the cycle coulombic efficiency results of the half-cells assembled with current collectors in Example 1 and Comparative Example 1.

[0047] Figure 3 The graph shows the polarization voltage results of the symmetrical cells assembled with current collectors in Example 1 and Comparative Example 1 during the cycling process.

[0048] Figure 4 (a) Voltage-time results of half-cell 10 assembled with current collectors of Example 1 and Comparative Example 1 during cycling; (b) A magnified comparison of the results within the red box in (a) of voltage-time results of half-cell 10 assembled with current collectors of Example 1 and Comparative Example 1 during cycling. Detailed Implementation

[0049] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available reagents and materials.

[0050] Example 1

[0051] This invention provides an embodiment of a DNA-coated current collector and its preparation method. The preparation method of the DNA-coated current collector described in this embodiment is as follows:

[0052] (1) Raw material pretreatment, cell lysis and impurity removal

[0053] I purchased Chinese aloe vera from JD.com, removed the outer skin, scraped out fresh aloe vera gel tissue, rinsed it with sterile water to remove the surface mucus, and then cut and ground it into a paste sample.

[0054] Add 5 times the volume of SDS buffer to the sample and lyse it in a 60°C water bath for 15 minutes. Mix well every 5 minutes to ensure complete reaction. The mass-volume percentage of SDS in the SDS buffer is 2% to obtain the lysate.

[0055] Add a NaCl solution with a volume of 10% of the lysis buffer volume, and treat in an ice bath for 10 minutes. The concentration of the NaCl solution is 2.0 mol / L. The solution becomes turbid. Filter with a filter screen and retain the filtrate.

[0056] (2) DNA precipitation, solid-liquid separation and preparation of coating solution

[0057] Add an equal volume of pre-cooled isopropanol to the filtrate obtained in step (1), mix gently, and let stand at -20°C for 20 minutes to allow DNA to form a white flocculent precipitate.

[0058] Set the centrifuge parameters to 12000 rpm and centrifuge for 5 minutes. Discard the supernatant to obtain a precipitate containing DNA. Wash with 70% ethanol to remove salt. After a short centrifugation, discard the ethanol and place the precipitate in a vacuum drying oven at 25°C for 24 hours to obtain a powder containing DNA.

[0059] Weigh 20 mg of powder, add 10 mL of deionized water and mix well to prepare a solution with a concentration of 2 mg / mL.

[0060] (3) Forming a DNA coating layer on silver foil

[0061] Prepare a 5cm×5cm silver foil, immerse it fully in the DNA-containing solution prepared in step (2), let it stand for 20 minutes to allow the DNA molecules to fully coat the surface of the silver foil, gently wash away the excess unreacted solution on the surface with deionized water, and then place it in a vacuum drying oven at 25°C for 24 hours to obtain the DNA-coated current collector.

[0062] Scanning electron microscopy (SEM) was used to observe the surface coating layer of the DNA-coated current collector prepared in this embodiment, which had a thickness of 1.2 μm. Figure 1- (b) It can be seen that a dense DNA coating layer is formed on the surface of the current collector.

[0063] Example 2

[0064] The only difference between Example 2 and Example 1 is that in step (1), the SDS buffer used for cell lysis contains 2.5% SDS by volume.

[0065] Example 3

[0066] The only difference between Example 3 and Example 1 is that in step (2), the precipitation condition after adding organic solvent is: standing in an ice bath for 30 minutes.

[0067] Example 4

[0068] The only difference between Example 4 and Example 1 is that in step (2), 15 mg of dried powder is weighed and added to 10 mL of deionized water to prepare a DNA-containing solution with a concentration of 1.5 mg / mL.

[0069] Comparative Example 1

[0070] The current collector in Comparative Example 1 is the same silver foil as in step (3) of Example 1, but without the coating treatment.

[0071] Scanning electron microscopy (SEM) was used to observe the surface of the silver foil, such as... Figure 1 - (a) can be seen that the surface of the untreated silver foil is smooth.

[0072] Comparative Example 2

[0073] The only difference between Comparative Example 2 and Example 1 is that the raw material for DNA extraction was replaced with edible cactus purchased from the JD.com e-commerce platform. The fleshy stem was peeled and extracted to obtain cactus DNA-coated Ag current collector.

[0074] Comparative Example 3

[0075] The only difference between Comparative Example 3 and Example 1 is that commercially available calf thymus DNA was mixed with water to prepare a solution of the same concentration, which replaced the extracted DNA solution. The coating operation in step (3) was performed directly to obtain Ag current collector coated with calf thymus DNA.

[0076] Comparative Example 4

[0077] The only difference between Comparative Example 4 and Example 1 is that the silver foil in step (3) is replaced with aluminum foil.

[0078] Example of effect

[0079] To investigate the application performance of the DNA-coated current collector provided by this invention and the effectiveness of its preparation method, the following tests were conducted:

[0080] 1. Lithium plating: Lithium was plated on the surface of the current collector in the examples and comparative examples respectively, with a current density of 1 mA·cm. -2 The surface capacity is 3mAh·cm³. -2 The surface morphology of the lithium-plated current collectors in Example 1 and Comparative Example 1 after lithium plating was analyzed by SEM, and the results are as follows: Figure 1 (cd);

[0081] 2. Half-cell assembly:

[0082] Current collectors: The current collectors used in the above embodiments and comparative examples are used respectively;

[0083] Active material layer: The mass ratio of active material LiCoO2: conductive agent Super P: binder PVDF is 8:1:1, which is coated on the current collector to obtain the working electrode;

[0084] Electrolyte: Lithium-sulfur electrolyte;

[0085] Counter electrode: Lithium metal sheet;

[0086] Membrane: Celgard 2325 (PP / PE / PP three-layer);

[0087] Battery casing: CR2032 button battery casing;

[0088] Assembly sequence: negative electrode shell, lithium sheet, electrolyte (40μL), separator, electrolyte (40μL), working electrode, gasket, spring sheet, positive electrode shell.

[0089] 3. Symmetrical battery assembly:

[0090] Current collectors: The current collectors used in the above embodiments and comparative examples are used respectively;

[0091] Active material layer: The mass ratio of active material LiCoO2: conductive agent Super P: binder PVDF is 8:1:1, which is coated on the current collector to obtain the working electrode;

[0092] Electrolyte: Lithium-sulfur electrolyte;

[0093] Counter electrode: Lithium metal sheet;

[0094] Membrane: Celgard 2325 (PP / PE / PP three-layer);

[0095] Battery casing: CR2032 button battery casing;

[0096] Assembly sequence: negative electrode shell, working electrode, lithium sheet, electrolyte, separator, electrolyte, Li sheet, working electrode, positive electrode shell.

[0097] 4. Cyclic test conditions: The test step parameters are shown in Table 1 below.

[0098] Table 1. Parameters for Cyclic Test Steps

[0099]

[0100] The 250-cycle coulombic efficiency results of the half-cells assembled with current collectors in Example 1 and Comparative Example 1 are as follows: Figure 2 The polarization voltage results of the symmetrical cells assembled with current collectors in Example 1 and Comparative Example 1 during cycling are as follows: Figure 3 The voltage-time results of the 10-cycle half-cell assembled with current collectors in Example 1 and Comparative Example 1 are as follows: Figure 4 (ab); Table 2 shows the results of the half-cell interface impedance, cyclic short-circuit condition and 10-cycle coulombic efficiency obtained by the current collector assembly of the examples and comparative examples.

[0101] 5. Histone residues: The DNA-containing powder or purchased DNA obtained from Examples 2-4 was subjected to sealed hydrolysis with hydrochloric acid and derivatization with benzoyl chloride. The characteristic peak of benzoylamine was detected by gas chromatography to analyze whether NH3 could be detected. The results are shown in Table 2.

[0102] Table 2 Performance test results of the examples and comparative examples

[0103]

[0104] Figure 1 (c) is a SEM image of the surface of the single silver current collector after lithium plating in Comparative Example 1; Figure 1 (d) is a SEM image of the surface of the DNA-coated current collector after lithium plating in Example 1. It can be seen that direct lithium plating on a single Ag foil is ineffective. Figure 1 (c) The lithium layer cannot form a dense, continuous film; obvious powder clusters or dendritic protrusions are present. However, after lithium plating on the DNA-coated current collector, Figure 1 (b) The lithium layer has fine particles on its surface without obvious sharp protrusions, presenting a relatively dense accumulation state, and there are no powder clusters or dendritic protrusions, which can avoid the risk of dendrites; at the same time, the lithium layer and the silver current collector interface are tightly bonded, without obvious gaps or peeling.

[0105] Depend on Figure 2-4 The comparison shows that:

[0106] Comparative Example 1, which used a half-cell without silver foil coating, showed a significant decrease in coulombic efficiency after 135 cycles, with an efficiency of 94% after 10 cycles; while the half-cell based on DNA-coated current collector of the present invention still maintained good battery stability and coulombic efficiency after 250 cycles, with a coulombic efficiency of 99.5% after 10 cycles.

[0107] According to the polarization voltage test results, the symmetric cell prepared in Comparative Example 1 without silver foil showed a significant increase in polarization voltage after 500 hours of cycling, and a short circuit occurred. In contrast, the symmetric cell using the DNA-coated current collector of this invention exhibited better cell stability, with no significant voltage increase or short circuit observed within 700 hours. Even from the magnified comparison of half-cell polarization voltages, it is still evident that the half-cell using the uncoated silver foil had a higher polarization voltage.

[0108] The above results correspond to the surface lithium layer condition of the current collector after lithium plating, further verifying that the DNA-coated current collector provided by the present invention has the advantages of effectively suppressing lithium dendrite growth and improving battery cycle performance.

[0109] Further comparison of the data in Table 2 shows that:

[0110] The specific extraction strategy used in Example 1 of this invention yields a current collector with aloe vera DNA coated on silver foil. The DNA is less prone to breakage during mechanical disruption, and the quality of the DNA molecular chain can be well preserved. At the same time, aloe vera polysaccharides can be efficiently removed by selective precipitation with NaCl. Compared with other current collectors coated or combined with plant DNA or animal DNA, this method can effectively avoid interface failure, lithium consumption, or safety risks, and has higher commercial feasibility.

[0111] In contrast, Comparative Example 2 used cactus DNA coating. Because the cell walls of cactus fleshy stems contain more lignin than the cell walls of aloe vera gel tissue, and cactus mucilage polysaccharides (such as arabinogalactan) are difficult to remove completely during the extraction process, the polysaccharides carbonize during the high-temperature battery cycling process, resulting in an increase in interfacial resistance.

[0112] Comparative Example 3 used commercially available animal DNA for coating, but the residual proteins in it decomposed under high pressure to produce NH3, posing a risk of corrosion with long-term use. The plant DNA used in this invention contains a higher abundance of guanine-cytosine (GC) base pairs, which can form a dense nitrogen coordination network, giving it unique lithium-ion affinity. At the same time, the plant cell wall polysaccharide fragments, such as hemicellulose derivatives, retained in the phosphodiester backbone of the DNA can mediate dynamic lithium-ion solvation through hydroxyl groups, and can also act as a mechanical buffer layer to alleviate the stress of electrode volume changes, resulting in better performance.

[0113] In Comparative Example 4, aluminum foil was used for preparation. An Al2O3 passivation film would form on the Al surface, causing the interfacial impedance to spike. Furthermore, Al itself has lower conductivity and coulombic efficiency, so the performance could not be significantly improved by using aluminum foil, making it unsuitable for the technical solution of this invention.

[0114] In summary, the specific extraction process provided by this invention establishes a three-in-one process system for targeted impurity removal, conformation protection, and zero-pollution residue of aloe vera gel tissue DNA. This system facilitates the formation of a DNA coating layer, achieving strong interfacial bonding and efficient dendrite inhibition. Furthermore, the chemical bonding with the silver current collector further enhances the interfacial strength, effectively inhibiting lithium dendrite growth. When applied to batteries, this system comprehensively improves cycle performance and extends battery life, providing a new approach to address the shortcomings of using single current collectors in existing technologies.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a current collector based on DNA coating, characterized in that, Includes the following steps: (1) Take aloe vera gel tissue and add it to SDS buffer to lyse it, then add NaCl solution to treat it and filter to obtain filtrate; (2) Add an organic solvent to the filtrate to precipitate, and separate the solid and liquid to obtain an active substance containing DNA, and prepare a solution containing DNA. (3) The solution containing DNA is applied to the surface of the silver foil, and after standing, it is dried to form a coating layer, thereby obtaining the DNA-coated current collector.

2. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (1), the reaction conditions for pyrolysis are: reacting at 55-65℃ for 10-20 minutes, and mixing once every 4-6 minutes; And / or, in step (1), the conditions for adding NaCl solution are an ice bath for 8-12 minutes.

3. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (1), the volume of the SDS buffer is 4-6 times the volume of the aloe vera gel tissue; And / or, in step (1), the mass-volume percentage of SDS in the SDS buffer is 1.5-2.5%.

4. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (1), the volume of the NaCl solution is 5-15% of the volume of the lysis solution; And / or, in step (1), the concentration of NaCl in the NaCl solution is 2.0-2.5 mol / L.

5. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (2), the organic solvent includes at least one of isopropanol and ethanol; And / or, in step (2), the temperature of the precipitation is -20 to 0°C and the precipitation time is 20 to 30 minutes.

6. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (2), the solid-liquid separation specifically involves centrifuging at 11000-12000 rpm for 5-6 minutes to remove the supernatant; And / or, in step (2), after precipitation and solid-liquid separation, there are also washing and drying steps to obtain DNA-containing powder and prepare a DNA-containing solution.

7. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (3), the concentration of the active substance containing DNA in the DNA-containing solution is 1.5-2.5 mg / ml; And / or, in step (3), the settling time is 15-25 minutes.

8. The method for preparing a current collector based on DNA coating as described in claim 1, characterized in that, In step (3), the thickness of the coating layer is 1.1-1.3 μm.

9. A DNA-coated current collector prepared by the method for preparing a DNA-coated current collector according to any one of claims 1-8.

10. The application of the DNA-coated current collector as described in claim 9 in lithium batteries.

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