High-performance stretchable electrode and preparation method and application thereof

Abstract

This application relates to the field of flexible stretchable electrode technology, and discloses a high-performance stretchable electrode, its preparation method, and its application. The preparation method includes: dissolving a hyperbranched polymer containing functional groups in a solvent to obtain a hyperbranched polymer solution; dispersing latex in a solvent to obtain an emulsion; adding the hyperbranched polymer solution to a silver nanowire dispersion for reaction, and collecting the solid product; dispersing the solid product in the emulsion to obtain a silver nanowire / emulsion ink; coating the silver nanowire / emulsion ink onto a flexible substrate, and performing demulsification treatment to obtain the high-performance stretchable electrode. In the stretchable electrode of this application, latex particles construct a continuous elastic network, tightly wrapping and embedding at the junctions of the silver nanowire network, forming a network structure that is both stretchable and highly conductive, exhibiting excellent electrical properties and cycle stability. Its tensile strain exceeds 500%, and at 100% tensile strain, the R / R0 is only 2.3; at 40% strain, it can withstand more than 10,000 tensile cycles.

Description

Technical Field

[0001] This application relates to the field of flexible stretchable electrode technology, specifically to a high-performance stretchable electrode, its preparation method, and its application. Background Technology

[0002] Stretchable electrodes directly determine the electromechanical stability and functional integrity of wearable devices under dynamic deformation. Printing technology provides an economical and efficient way to manufacture stretchable electrodes, and much research has focused on developing printable electrode materials that possess both high conductivity and mechanical flexibility. Silver nanowires (AgNWs) show great potential in stretchable electrodes due to their high conductivity, solution processability, and ability to form flexible conductive networks.

[0003] Currently, stretchable electrodes based on silver nanowires are widely studied. For example, patent CN 120690508 A discloses a method for preparing a modified stretchable electrode, which involves spin-coating a silver nanowire dispersion onto a substrate, preparing a patterned silver nanowire film, modifying it, and then coating an organic polymer solution onto the modified silver nanowire film to prepare the modified stretchable electrode. Patent CN 117612770 A discloses a flexible thin-film electrode and its preparation method, which involves preparing a silver nanowire thin-film solution, then transferring the silver nanowire thin-film solution and performing post-processing to obtain a flexible thin-film electrode. However, the above methods are complex in their preparation processes. They typically require the addition of large amounts of additives (such as sulfonate ions) when preparing the silver nanowire thin-film solution. The use of additives to stabilize the silver nanowire ink inevitably hinders the contact between the silver nanowires, and subsequent post-processing (such as acetone washing) may damage the stretchable substrate or electronic components. Meanwhile, the aforementioned methods, which incorporate silver nanowires into an elastomer matrix to impart stretchability, often disrupt the conductive network connections by physically isolating the silver nanowires. Furthermore, dissolving the elastic matrix requires the use of large quantities of toxic reagents (such as toluene), increasing the hazardous nature of the production process and the risk of environmental pollution. In addition, existing methods struggle to achieve high-precision printing on various flexible substrates, posing challenges in constructing stretchable electrodes with high resolution, high conductivity, and high tensile cycle stability.

[0004] Therefore, there is an urgent need to develop a new method for preparing stretchable silver nanowire electrodes. Summary of the Invention

[0005] This application provides a high-performance stretchable electrode, its preparation method, and its application, aiming to solve the technical problems of complex preparation processes and environmental pollution of existing stretchable electrodes, as well as the technical problems of low stretch conductivity, large variation in normalized resistance during stretching, and poor stability during stretching cycles of existing stretchable electrodes.

[0006] To achieve the above objectives, the present application adopts the following technical solution.

[0007] A first aspect of this application provides a method for fabricating a high-performance stretchable electrode, comprising:

[0008] S1, dissolve the hyperbranched polymer containing functional groups in a solvent to obtain a hyperbranched polymer solution; disperse the latex in a solvent to obtain an emulsion;

[0009] S2, add the hyperbranched polymer solution to the silver nanowire dispersion to react, and collect the solid product; disperse the solid product in an emulsion to obtain the silver nanowire / emulsion ink;

[0010] S3. Silver nanowires / emulsion ink are coated onto a flexible substrate, and after demulsification treatment, a high-performance stretchable electrode is obtained.

[0011] Preferably, the hyperbranched polymer containing functional groups includes any one of carboxyl, sulfonic acid, hydroxyl, mercapto, carbonyl, primary amine, secondary amine or tertiary amine.

[0012] More preferably, the functional group is a primary amine;

[0013] The chemical structure of the hyperbranched polymer is shown in any one of formulas (1)-(3):

[0014] (1)

[0015] (2)

[0016] (3).

[0017] Preferably, the latex includes at least one of acrylic latex, polyurethane latex, polyacrylate copolymer latex, vinyl acetate-ethylene copolymer latex, or epoxy latex;

[0018] The solvent includes at least one of water, methanol, ethanol, n-propanol, isopropanol, or n-butanol;

[0019] The flexible substrate includes at least one of polyurethane (PU), polydimethylsiloxane (PDMS), polybutylene terephthalate (Ecoflex), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), or natural rubber.

[0020] Preferably, the demulsification treatment includes room temperature demulsification and / or demulsification at 90~150°C. o C. Drying and demulsification.

[0021] Preferably, the coating method is screen printing.

[0022] Preferably, the concentration of silver nanowires in the silver nanowire dispersion is 0.1~20 mg / mL;

[0023] The amount of the hyperbranched polymer containing functional groups is 0.01~25 wt% of the amount of silver nanowires.

[0024] The amount of latex used is 0.01~5wt% of the amount of silver nanowires used.

[0025] Preferably, the silver nanowire content in the silver nanowire / emulsion ink is 0.01~20wt%.

[0026] A second aspect of this application provides a high-performance stretchable electrode prepared by the above-described preparation method.

[0027] A third aspect of this application provides the application of the aforementioned high-performance stretchable electrode in electrode materials, flexible electronics, or wearable devices.

[0028] Compared with the prior art, the beneficial effects of this application are as follows:

[0029] The method for preparing silver nanowire / emulsion stretchable electrodes in this application is simple. The silver nanowire / emulsion ink uses hyperbranched polymers as dispersants, surface stabilizers, and rheology modifiers, without the need for other additives. It is green and environmentally friendly and suitable for large-scale production.

[0030] In this application, the hyperbranched polymer adsorbs functional groups (anchoring groups) onto the surface of silver nanowires and induces steric stabilization through the interaction between the solvated chains and the solvent, resulting in uniform dispersion of the silver nanowires in the solvent. The disentanglement of the hyperbranched polymer molecular chains regulates the viscosity and rheological properties of the silver nanowire / emulsion ink, enabling it to maintain excellent dispersibility and high stability even at high solids content. This ink can be screen-printed with high precision on various flexible substrates. The silver nanowire / emulsion ink concentration of this application can reach 90 mg / mL, and the screen printing precision can reach 30 µm.

[0031] After screen printing, the silver nanowire / emulsion ink of this application deposits silver nanowires due to their own gravity, forming a conductive network structure. As the solvent evaporates, latex particles gradually deposit, aggregating and tightly arranging themselves around the pre-formed silver nanowire network. When the solvent is completely removed, capillary forces and surface tension cause the latex particles to break and fuse into a continuous elastic network, tightly wrapping and embedding themselves at the junctions of the silver nanowire network, forming a network structure that is both stretchable and highly conductive.

[0032] The stretchable electrode of this application exhibits excellent electrical properties and cyclic stability, with a tensile strain exceeding 500%. At 100% tensile strain, the R / R0 ratio is only 2.3; at 40% strain, it can withstand more than 10,000 tensile cycles. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 Silver nanowire / acrylic emulsion ink A prepared in Example 1 80 E 0.25 A picture of the actual product;

[0035] Figure 2 Silver nanowire / acrylic emulsion ink A prepared in Example 2 80 E 0.5 A picture of the actual product;

[0036] Figure 3 Silver nanowire / acrylic emulsion ink A prepared in Example 3 80 E 0.15 A picture of the actual product;

[0037] Figure 4 Silver nanowire / acrylic emulsion ink A prepared in Example 6 90 E 0.25 A picture of the actual product;

[0038] Figure 5 Silver nanowire / acrylic emulsion ink A prepared in Example 7 40 E 0.25 A picture of the actual product;

[0039] Figure 6 Example 1, A 80 E 0.25 A photograph of ink printed on a PDMS substrate;

[0040] Figure 7 An optical microscope image of the stretchable electrode of Example 1;

[0041] Figure 8 The graph shows the normalized resistance (R / R0) test results of the stretchable electrode of Example 1 under 100% tensile strain.

[0042] Figure 9The graph shows the normalized resistance (R / R0) test results of the stretchable electrode of Example 1 under 40% tensile strain. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0044] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0045] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0046] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0047] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0048] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0049] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0050] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0051] In a first aspect, this application provides a method for preparing a high-performance stretchable electrode, comprising:

[0052] S1, dissolve the hyperbranched polymer containing functional groups in a solvent to obtain a hyperbranched polymer solution; disperse the latex in a solvent to obtain an emulsion;

[0053] In this application, the hyperbranched polymer containing functional groups can simultaneously function as a dispersant, surface stabilizer, and rheology modifier, avoiding the use of other additives. This not only improves electrical conductivity but also simplifies the preparation process and reduces environmental pollution, making the preparation method of this application simple, environmentally friendly, and suitable for large-scale production. The functional groups in the hyperbranched polymer are selected from any one of carboxyl, sulfonic acid, hydroxyl, mercapto, carbonyl, primary amine, secondary amine, or tertiary amine, preferably primary amine.

[0054] As a preferred embodiment of this application, the hyperbranched polymer is a compound of formula (1)-(3):

[0055] (1)

[0056] (2)

[0057] (3).

[0058] In this application, the latex is used to form a continuous elastic network, which, in conjunction with silver nanowires, constructs a network structure that is both stretchable and highly conductive. The latex is selected from at least one of acrylic latex, polyurethane latex, polyacrylate copolymer latex, vinyl acetate-ethylene copolymer latex, or epoxy latex.

[0059] The solvent is selected from at least one of water, methanol, ethanol, n-propanol, isopropanol, or n-butanol.

[0060] S2, add the hyperbranched polymer solution to the silver nanowire dispersion for reaction, the reaction time is 5-60 min, and the solid product is collected by centrifugation; disperse the solid product in an emulsion to obtain silver nanowire / emulsion ink;

[0061] In this application, the silver nanowire dispersion is prepared by adding a silver ion-containing solution to a PVP composite solution, stirring until homogeneous, and then heating to 100-120°C. o The reaction proceeds with C, and then the mixture is rapidly cooled to room temperature to obtain the final product.

[0062] The silver ion solution is an ethylene glycol solution of silver nitrate with a concentration of 0.04~0.1 g / mL;

[0063] The PVP composite solution is prepared by the following method: an ethylene glycol solution of PVP with a concentration of 0.01~0.02 g / mL and an ethylene glycol solution of sodium chloride with a concentration of 7~8 mM are prepared separately; the ethylene glycol solution of sodium chloride is added to the ethylene glycol solution of PVP and mixed thoroughly to obtain the PVP composite solution. Preferably, the volume ratio of the ethylene glycol solution of silver nitrate, the ethylene glycol solution of PVP, and the ethylene glycol solution of sodium chloride is 1:4:(0.25~0.75).

[0064] In this application, it is preferred to concentrate the silver nanowire dispersion to a concentration of 0.1~20 mg / mL;

[0065] The amount of the hyperbranched polymer containing functional groups is preferably 0.01 to 25 wt% of the amount of silver nanowires; the amount of the latex is preferably 0.01 to 5 wt% of the amount of silver nanowires.

[0066] The silver nanowire / emulsion ink prepared in this application has a silver nanowire content of 0.01~20wt% and a viscosity of 0.01~10000Pa·s; wherein the silver nanowire has a diameter of 10~150nm and a length of 5~200µm.

[0067] S3, silver nanowire / emulsion ink is coated onto a flexible substrate, and after demulsification treatment, a high-performance stretchable electrode is obtained. The silver nanowire content in the silver nanowire / emulsion ink is preferably 0.01~20wt%.

[0068] In this application, the flexible substrate includes at least one of polyurethane (PU), polydimethylsiloxane (PDMS), polybutylene terephthalate (Ecoflex), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), or natural rubber.

[0069] The coating is applied using a screen printing method, where silver nanowires / emulsion ink are printed onto a flexible substrate.

[0070] The demulsification process involves placing the product at room temperature and / or at 90-150°C, respectively. o Drying at C causes the solvent to evaporate and the emulsion to demulsify. As a preferred embodiment of this application, the demulsification process is first performed at 0-30°C. o Dry at C for 0.5-24 hours, then heat to 90-150°C. o Dry at C for 10-60 minutes to allow the solvent to evaporate and the emulsion to break.

[0071] The silver nanowire / emulsion ink of this application comprises a hyperbranched polymer that adsorbs functional groups (anchoring groups) onto the surface of silver nanowires and induces steric stabilization through the interaction between the solvated chains and the solvent, resulting in uniform dispersion of the silver nanowires in the solvent. The viscosity and rheological properties of the silver nanowire ink are controlled by the deentanglement of the hyperbranched polymer molecular chains, enabling the silver nanowire / emulsion ink to maintain excellent dispersibility and high stability even at high solids content. It can be screen-printed on various flexible substrates with high precision. The concentration of the silver nanowire / emulsion ink can reach 90 mg / mL, and the screen printing precision can reach 30 µm.

[0072] After screen printing, the silver nanowire / emulsion ink of this application deposits silver nanowires due to their own gravity, forming a conductive network structure. As the solvent evaporates, latex particles gradually deposit, aggregating and tightly arranging themselves around the pre-formed silver nanowire network. When the solvent is completely removed, capillary forces and surface tension cause the latex particles to break and fuse into a continuous elastic network, tightly wrapping and embedding themselves at the junctions of the silver nanowire network, forming a network structure that is both stretchable and highly conductive.

[0073] The high-performance stretchable electrode prepared in this application has a tensile strain exceeding 500%; at 100% tensile strain, the R / R0 is only 2.3; at 40% strain, it can be stretched for more than 10,000 tensile cycles, exhibiting excellent tensile conductivity and tensile cycle performance. It can be applied in electrode materials, flexible electronics, and wearable devices.

[0074] The present application will be further illustrated by the following examples.

[0075] In the embodiments of this application, the terminal amino hyperbranched polymers are prepared by the method disclosed in ACS Sustain. Chem. Eng. 5, 10258-10265 (2017). The three terminal amino hyperbranched polymers of formulas (1)-(3) are named HPA-4, HPA-8, and HPA-16, respectively, and their chemical structures are shown below:

[0076] HPA-4:

[0077]

[0078] HPA-8:

[0079]

[0080] HPA-16:

[0081]

[0082] Example: Preparation of silver nanowire dispersion

[0083] Weigh 2g of AgNO3 and place it in a brown round-bottom flask. Add 40mL of ethylene glycol and stir magnetically for 0.5h until AgNO3 is completely dissolved to obtain an AgNO3 solution.

[0084] Weigh 2g of PVP into a brown round-bottom flask, add 160ml of ethylene glycol, heat and stir magnetically for 3h until PVP is completely dissolved; add 16.32mL of 7.2mM NaCl / ethylene glycol solution, stir for 5min, mix well, and cool to room temperature to obtain PVP composite solution;

[0085] Under magnetic stirring, AgNO3 solution was added to the PVP composite solution and stirred for 10 minutes to ensure homogeneity. The mixture was then placed in a forced-air drying oven at 110°C. o The reaction was heated at C for 12 hours. After the reaction was completed, the mixture was rapidly cooled to room temperature in a cold water bath to obtain the silver nanowire stock solution.

[0086] The silver nanowire stock solution was purified with ethanol using a stirring-induced centrifugal force-vertical filtration purification device (patented patent ZL202221176878.7) to remove impurities. After 200 minutes of filtration purification, the addition of ethanol was stopped, and stirring was continued while filtering until the concentration of the silver nanowire dispersion was 1 mg / mL. Stirring was then stopped and the product was received from the discharge pipe of the internal cavity base.

[0087] Example 1

[0088] This embodiment provides a method for preparing a stretchable electrode, including:

[0089] S1. Weigh 10 mg of terminal amino hyperbranched polymer (HPA-16) and dissolve it in 10 mL of ethanol to prepare an HPA-16 / ethanol solution with a concentration of 1 mg / mL.

[0090] Weigh 2.18 mg of acrylic latex and disperse it in 1 mL of isopropanol to prepare an acrylic / isopropanol emulsion;

[0091] S2, take 80 mL of a 1 mg / mL silver nanowire dispersion, add 80 µL of a 1 mg / mL HPA-16 / ethanol solution, mix and react for 15 min, then centrifuge to collect the solid product; disperse the solid product in the acrylic / isopropanol emulsion in S1 to obtain a silver nanowire / acrylic emulsion ink with a latex content of 0.25 wt% and a silver nanowire concentration of 80 mg / mL, denoted as A. 80 E 0.25 .

[0092] S3, the silver nanowire / acrylic emulsion ink of S2 is screen-printed onto a PU substrate, and then... (The sentence is incomplete and requires more context to translate accurately.) o Dry at C for 0.5 h, 120 o Drying at C for 10 minutes to demulsify yields a stretchable electrode.

[0093] Example 2

[0094] This embodiment provides a method for preparing a stretchable electrode, including:

[0095] S1 differs from Example 1 in that the mass of the acrylic latex is 4.35 mg;

[0096] S2, the same as in Example 1, yielded a silver nanowire / acrylic emulsion ink with a latex content of 0.5 wt% and a silver nanowire concentration of 80 mg / mL, denoted as A. 80 E 0.5 ;

[0097] S3 is the same as in Example 1.

[0098] Example 3

[0099] This embodiment provides a method for preparing a stretchable electrode, including:

[0100] S1 differs from Example 1 in that the mass of the acrylic latex is 1.3 mg;

[0101] S2, the same as in Example 1, yielded a silver nanowire / acrylic emulsion ink with a latex content of 0.15 wt% and a silver nanowire concentration of 80 mg / mL, denoted as A. 80 E 0.15 ;

[0102] S3 is the same as in Example 1.

[0103] Example 4

[0104] This embodiment provides a method for preparing a stretchable electrode, including:

[0105] S1 is the same as in Example 1;

[0106] S2 is the same as in Example 1;

[0107] S3 differs from Example 1 in that, at 25 o Demulsification was performed by drying at C for 0.5 h, and the rest was the same as in Example 1.

[0108] Example 5

[0109] This embodiment provides a method for preparing a stretchable electrode, including:

[0110] S1 is the same as in Example 1;

[0111] S2 is the same as in Example 1;

[0112] S3 differs from Example 1 in that, at 120... o Demulsification was performed by drying at C for 10 minutes, and the rest was the same as in Example 1.

[0113] Example 6

[0114] This embodiment provides a method for preparing a stretchable electrode, including:

[0115] S1. Weigh 10 mg of terminal amino hyperbranched polymer (HPA-16) and dissolve it in 10 mL of ethanol to prepare an HPA-16 / ethanol solution with a concentration of 1 mg / mL.

[0116] Weigh 2.2 mg of acrylic latex and disperse it in 1 mL of isopropanol to prepare an acrylic / isopropanol emulsion;

[0117] S2, take 90 mL of a 1 mg / mL silver nanowire dispersion, add 90 µL of a 1 mg / mL HPA-16 / ethanol solution, mix and react for 15 min, then centrifuge to collect the solid product; disperse the solid product in the acrylic / isopropanol emulsion in S1 to obtain a silver nanowire / acrylic emulsion ink with a latex content of 0.25 wt% and a silver nanowire concentration of 90 mg / mL, denoted as A. 90 E 0.25 .

[0118] S3, the silver nanowire / acrylic emulsion ink of S2 is screen-printed onto a PU substrate, and then... (The sentence is incomplete and requires more context to translate accurately.) o Dry at C for 0.5 h, 120 o Drying at C for 10 minutes to demulsify yields a stretchable electrode.

[0119] Example 7

[0120] This embodiment provides a method for preparing a stretchable electrode, including:

[0121] S1. Weigh 10 mg of terminal amino hyperbranched polymer (HPA-16) and dissolve it in 10 mL of ethanol to prepare an HPA-16 / ethanol solution with a concentration of 1 mg / mL.

[0122] Weigh 2.07 mg of acrylic latex and disperse it in 1 mL of isopropanol to prepare an acrylic / isopropanol emulsion;

[0123] S2, take 40 mL of a 1 mg / mL silver nanowire dispersion, add 40 µL of a 1 mg / mL HPA-16 / ethanol solution, mix and react for 15 min, then centrifuge to collect the solid product; disperse the solid product in the acrylic / isopropanol emulsion in S1 to obtain a silver nanowire / acrylic emulsion ink with a latex content of 0.25 wt% and a silver nanowire concentration of 40 mg / mL, denoted as A. 40 E 0.25 .

[0124] S3, the silver nanowire / acrylic emulsion ink of S2 is screen-printed onto a PU substrate, and then... (The sentence is incomplete and requires more context to translate accurately.) o Dry at C for 0.5 h, 120 o Drying at C for 10 minutes to demulsify yields a stretchable electrode.

[0125] Silver nanowire / acrylic emulsion ink A prepared in Example 1 80 E 0.25 The actual object is as follows Figure 1 As shown. By Figure 1 It can be seen that its color is a uniform silver-gray, and the silver nanowires / acrylic latex are stably dispersed in isopropanol.

[0126] Silver nanowire / acrylic emulsion ink A prepared in Example 2 80 E 0.5 The actual object is as follows Figure 2 As shown. By Figure 2 It can be seen that its color is a uniform silver-gray, and the silver nanowires / acrylic latex are stably dispersed in isopropanol.

[0127] Silver nanowire / acrylic emulsion ink A prepared in Example 3 80 E 0.15 The actual object is as follows Figure 3 As shown. By Figure 3 It can be seen that its color is a uniform silver-gray, and the silver nanowires / acrylic latex are stably dispersed in isopropanol.

[0128] Silver nanowire / acrylic emulsion ink A prepared in Example 6 90 E 0.25 The actual object is as follows Figure 4 As shown. By Figure 4It can be seen that its color is a uniform silver-gray, and the silver nanowires / acrylic latex are stably dispersed in isopropanol.

[0129] Silver nanowire / acrylic emulsion ink A prepared in Example 7 40 E 0.25 The actual object is as follows Figure 5 As shown. By Figure 5 It can be seen that its color is a uniform silver-gray, and the silver nanowires / acrylic latex are stably dispersed in isopropanol.

[0130] Example 1, A 80 E 0.25 The ink is printed on a PDMS substrate, and the actual product image is as follows. Figure 6 As shown, A 80 E 0.25 The ink can be continuously printed at high resolution on a PDMS substrate.

[0131] The performance of the stretchable electrode from Example 1 was tested and its printing resolution evaluated, as detailed below:

[0132] An optical microscope image of the stretchable electrode in Example 1 is shown below. Figure 7 As shown, by Figure 7 It can be seen that its line width accuracy can reach 30µm.

[0133] The stretchable electrode of Example 1 was subjected to normalized resistance (R / R0) tests at 100% and 40% tensile strain, respectively, and the test results are as follows: Figure 8 and Figure 9 As shown. By Figure 8 It can be seen that under 100% tensile strain, R / R0 is only 2.3, and the stretchable electrode can stably cycle 1000 times; from Figure 9 It can be seen that under 40% tensile strain, R / R0 is only 1.4, and the stretchable electrode can be stably cycled 10,000 times.

[0134] The conductivity of the stretchable electrodes prepared in Examples 1-7 was tested, and the test results are shown in Table 1.

[0135] Table 1. Conductivity test values ​​of stretchable electrodes

[0136]

[0137] As shown in Table 1, the stretchable electrodes of Examples 1-7 all exhibit high conductivity after being stretched by 50%. Among them, the stretchable electrode of Example 1 has the highest conductivity retention rate under the 50% tensile strain condition.

[0138] The normalized resistance (R / R0) of the stretchable electrodes prepared in Examples 1-7 was tested, and the test results are shown in Table 2.

[0139] Table 2. R / R0 test values ​​of stretchable electrodes

[0140]

[0141] As shown in Table 2, the stretchable electrodes of Examples 1-7 exhibited stable and gradual resistance changes during the stretching process, with relatively small R / R0 values; among them, the stretchable electrodes of Examples 1 and 2 could be stretched up to 500.

[0142] The above demonstrates that the silver nanowire / emulsion ink of this application maintains excellent dispersibility and high stability even at high solid content. It can be screen-printed onto various flexible substrates with high precision to obtain stretchable electrodes. The stretchable electrodes of this application exhibit excellent electrical properties and cycling stability.

[0143] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A method for preparing a high-performance stretchable electrode, characterized in that, include: S1, dissolve the hyperbranched polymer containing functional groups in a solvent to obtain a hyperbranched polymer solution; disperse the latex in a solvent to obtain an emulsion; S2, add the hyperbranched polymer solution to the silver nanowire dispersion to react, and collect the solid product; disperse the solid product in an emulsion to obtain the silver nanowire / emulsion ink; S3. Silver nanowires / emulsion ink are coated onto a flexible substrate, and after demulsification treatment, a high-performance stretchable electrode is obtained.

2. The preparation method according to claim 1, characterized in that, The hyperbranched polymer containing functional groups includes any one of carboxyl, sulfonic acid, hydroxyl, mercapto, carbonyl, primary amine, secondary amine or tertiary amine.

3. The preparation method according to claim 2, characterized in that, The functional group is a primary amine; the chemical structure of the hyperbranched polymer is shown in any one of formulas (1)-(3): (1) (2) (3)。 4. The preparation method according to claim 1, characterized in that, The latex includes at least one of acrylic latex, polyurethane latex, polyacrylate copolymer latex, vinyl acetate-ethylene copolymer latex, or epoxy latex; The solvent includes at least one of water, methanol, ethanol, n-propanol, isopropanol, or n-butanol; The flexible substrate includes at least one of polyurethane (PU), polydimethylsiloxane (PDMS), polybutylene terephthalate (Ecoflex), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), or natural rubber.

5. The preparation method according to claim 1, characterized in that, The demulsification process includes room temperature demulsification and / or demulsification at 90~150°C. o C. Drying and demulsification.

6. The preparation method according to claim 1, characterized in that, The coating method is screen printing.

7. The preparation method according to claim 1, characterized in that, The concentration of silver nanowires in the silver nanowire dispersion is 0.1~20 mg / mL; The amount of the hyperbranched polymer containing functional groups is 0.01~25 wt% of the amount of silver nanowires. The amount of latex used is 0.01~5wt% of the amount of silver nanowires used.

8. The preparation method according to claim 1, characterized in that, The silver nanowire content in the silver nanowire / emulsion ink is 0.01~20wt%.

9. A high-performance stretchable electrode prepared by the preparation method according to any one of claims 1-8.

10. The application of the high-performance stretchable electrode of claim 9 in electrode materials, flexible electronics, or wearable devices.

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