Conductive fiber and preparation method and application thereof
By preparing conductive fibers, the problem of poor ductility of electronic products when bent at large angles is solved, flexibility and conductivity are improved, and the stability and service life of the circuit system are ensured.
Patent Information
- Application Number
- CN202511278918.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-10-17
AI Technical Summary
When existing electronic products are bent at large angles, the circuit system has poor ductility, leading to stress concentration and damage, affecting their use.
The conductive fiber preparation method is adopted. By mixing indium nitrate, carbon nanotubes, polyvinyl pyrrolidone and urea aqueous solution, electrospinning and temperature treatment are performed to form a porous structure fiber matrix, and a liquid indium layer is coated on the fiber surface and hot-pressed to form a conductive network.
It improves the flexibility and conductivity of the fiber, avoids stress concentration, ensures ductility and long-term operation in complex environments, and has excellent mechanical properties and high finished product yield.
Smart Images
Figure CN120797256A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of special fibers, in particular to a conductive fiber and a preparation method and application thereof. BACKGROUND
[0002] Under the background of electrification, electronic products have become more and more important tools in daily life. In order to cope with the increasingly complex working environment, it has become a key research direction to enable electronic products to adjust the morphology according to the change of application scene. However, most of the existing products often use hard metal to ensure current transmission. When a large angle bending occurs, the internal circuit system has low ductility and cannot timely ensure the change of shape. In this case, if the bending continues, a large amount of stress concentration will be generated, thereby causing damage or fracture of the circuit and affecting the use of the product. Therefore, how to improve the ductility and flexibility of the current transmission system while ensuring the transmission of current has become a problem to be solved for electrical products. SUMMARY
[0003] The present application aims to overcome the poor ductility of the current transmission system and provide a conductive fiber and a preparation method and application thereof.
[0004] In order to achieve the above-mentioned application purpose, the present application provides the following technical scheme: The present application provides a preparation method of a conductive fiber, comprising the following steps: (1) mixing indium nitrate, carbon nanotubes, ethanol and acetylacetone to obtain a metal salt solution; (2) mixing polyvinylpyrrolidone, urea aqueous solution and ethanol to obtain a spinning base solution; (3) mixing the metal salt solution and the spinning base solution, then performing electrospinning and temperature treatment to obtain a fiber template; (4) coating the surface of the fiber template with liquid indium and hot pressing to obtain the conductive fiber.
[0005] Preferably, the mass ratio of the indium nitrate and the carbon nanotubes in step (1) is 3-5:1-2. In step (1), the mass-volume ratio of the indium nitrate, ethanol and acetylacetone is 3-5 g:40-50 mL:20-30 mL.
[0006] Preferably, the rotation speed of the mixing in step (1) is 400-500 rpm and the time is 10-30 min.
[0007] Preferably, the mass ratio of the polyvinylpyrrolidone in step (2) and the indium nitrate in step (1) is 3-4:3-5. In the urea aqueous solution in step (2), the mass ratio of urea and water is 0.5-1:50-60.
[0008] Preferably, the mass-volume ratio of the polyvinylpyrrolidone, the aqueous urea solution and the ethanol in step (2) is 3-4 g: 20-30 mL: 20-30 mL.
[0009] Preferably, the rotation speed of the mixing in step (2) is 400-500 rpm, and the time is 5-20 min. The frequency of the mixing in step (3) is 25-30 kHz, and the time is 0.5-1 h.
[0010] Preferably, the propulsion rate of the electrospinning in step (3) is 1-1.5 mL / h, the voltage is 5-6 kV, the collection distance is 5-15 cm, the inner diameter of the nozzle is 0.5-1 mm, and the temperature is 20-25℃. The temperature treatment in step (3) is sequentially performed preliminary calcination, reduction calcination and activation treatment. The temperature of the preliminary calcination is 250-350℃, and the time is 1-2 h. The atmosphere of the reduction calcination comprises hydrogen and argon, and the volume fraction of the hydrogen is 5-10%. The temperature of the reduction calcination is 450-500℃, and the time is 2-4 h. The temperature of the activation treatment is 270-280℃, and the time is 30-60 min.
[0011] Preferably, the temperature of the liquid indium in step (4) is 180-185℃. The pulling speed of the coating in step (4) is 2-5 mm / s, and the immersion time is 1-3 s. The temperature of the hot pressing in step (4) is 140-150℃, the pressure is 0.4-0.6 MPa, and the time is 30-60 s.
[0012] The application further provides the conductive fiber prepared by the preparation method of the conductive fiber.
[0013] The application further provides the application of the conductive fiber in a flexible electronic device.
[0014] The application provides a preparation method of conductive fibers, comprising the following steps: mixing indium nitrate, carbon nanotubes, ethanol and acetylacetone to obtain a metal salt solution; mixing polyvinylpyrrolidone, an aqueous urea solution and ethanol to obtain a spinning base solution; mixing the metal salt solution and the spinning base solution, and then performing electrostatic spinning and temperature treatment to obtain a fiber template; and performing liquid indium coating and hot pressing on the surface of the fiber template to obtain the conductive fibers. In the conductive fibers provided by the application, indium nitrate and carbon nanotubes are used as raw materials, acetylacetone is used for chelation, and the indium nitrate is fixed on the carbon nanotubes; subsequently, polyvinylpyrrolidone and urea are used as the spinning base solution, mixed with the metal salt solution, and then spun together to obtain fibers; the obtained fibers are subjected to two-step calcination and activation treatment, the first step of calcination is to promote the decomposition of urea and reduce indium nitrate to indium oxide, so that a fiber matrix with a porous structure is obtained, the weight of the fiber is reduced, the softness is improved, and the carbon nanotubes are uniformly distributed in the pores to form a conductive network; the second step of calcination is performed in a hydrogen atmosphere to reduce the indium oxide to metal indium with uniform size, and the conductivity of the fiber is further improved; finally, a metal indium layer is coated on the surface of the fiber, indium has good ductility, so that the conductivity of the fiber is improved, and the fiber is also ensured to be ductile in a complex environment, the internal structure is prevented from being eroded by the external environment because of the coated indium metal layer, and a longer working time is achieved; the thickness uniformity of the fiber is improved through hot pressing.
[0015] The conductive fibers provided by the application use indium as the conductive metal, and the light weight and bending of the fibers are ensured through the hollow fiber mode; indium is a ductile metal, the shape is changed accordingly according to the change of the scene, and the stress concentration problem caused by large-angle bending is also avoided due to the hollow fiber structure. In the case of damage to the surface conductive metal layer, the normal work can still be ensured through the internal conductive network, and the long-acting property is achieved. The conductive fibers provided by the application have good mechanical properties and excellent conductivity while ensuring light weight, and the preparation method is simple, the process requirement is low, the yield of finished products is high, and the method is suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 SEM image of the conductive fibers of Example 1; Figure 2 SEM image of the conductive fibers of Comparative Example 2; Figure 3 Elongation rate graph of the conductive fibers of Example 1; Figure 4 Elongation rate graph of the conductive fibers of Comparative Example 2. DETAILED DESCRIPTION
[0017] The application provides a preparation method of conductive fibers, comprising the following steps: (1) mixing indium nitrate, carbon nanotubes, ethanol and acetylacetone to obtain a metal salt solution; (2) mixing polyvinylpyrrolidone, urea aqueous solution and ethanol to obtain a spinning base solution; (3) mixing the metal salt solution and the spinning base solution, then performing electrospinning and temperature treatment to obtain a fiber template; (4) performing liquid indium coating and hot pressing on the surface of the fiber template to obtain the conductive fiber.
[0018] In the present application, the mass ratio of the indium nitrate and the carbon nanotubes in step (1) is preferably 3-5:1-2, further preferably 3.5-4.5:1.2-1.8, and more preferably 3.8-4.2:1.4-1.6.
[0019] In the present application, the mass-volume ratio of the indium nitrate, ethanol and acetylacetone in step (1) is preferably 3-5 g:40-50 mL:20-30 mL, further preferably 3.5-4.5 g:42-48 mL:22-28 mL, and more preferably 3.8-4.2 g:44-46 mL:24-26 mL.
[0020] In the present application, the rotation speed of the mixing in step (1) is preferably 400-500 rpm, further preferably 420-480 rpm, and more preferably 440-460 rpm; and the time is preferably 10-30 min, further preferably 15-25 min, and more preferably 18-22 min.
[0021] In the present application, the mass ratio of the polyvinylpyrrolidone and the indium nitrate in step (1) in step (2) is preferably 3-4:3-5, further preferably 3.2-3.8:3.5-4.5, and more preferably 3.4-3.6:3.8-4.2.
[0022] In the present application, the mass ratio of the urea and water in the urea aqueous solution in step (2) is preferably 0.5-1:50-60, further preferably 0.6-0.9:52-58, and more preferably 0.7-0.8:54-56.
[0023] In the present application, the mass-volume ratio of the polyvinylpyrrolidone, urea aqueous solution and ethanol in step (2) is preferably 3-4 g:20-30 mL:20-30 mL, further preferably 3.2-3.8 g:22-28 mL:22-28 mL, and more preferably 3.4-3.6 g:24-26 mL:24-26 mL.
[0024] In the present application, the rotating speed of the mixing in step (2) is preferably 400-500 rpm, further preferably 420-480 rpm, and more preferably 440-460 rpm; and the time is preferably 5-20 min, further preferably 10-15 min, and more preferably 12-13 min.
[0025] In the present application, the frequency of the mixing in step (3) is preferably 25-30 kHz, further preferably 26-29 kHz, and more preferably 27-28 kHz; and the time is preferably 0.5-1 h, further preferably 0.6-0.9 h, and more preferably 0.7-0.8 h.
[0026] In the present application, the advancing speed of the electrospinning in step (3) is preferably 1-1.5 mL / h, further preferably 1.1-1.4 mL / h, and more preferably 1.2-1.3 mL / h; the voltage is preferably 5-6 kV, further preferably 5.2-5.8 kV, and more preferably 5.4-5.6 kV; the collection distance is preferably 5-15 cm, further preferably 6-14 cm, and more preferably 8-12 cm; the inner diameter of the nozzle is preferably 0.5-1 mm, further preferably 0.6-0.9 mm, and more preferably 0.7-0.8 mm; and the temperature is preferably 20-25℃, further preferably 21-24℃, and more preferably 22-23℃.
[0027] In the present application, the electrospun fibers are allowed to stand after being obtained, and the standing temperature is preferably 20-25℃, further preferably 21-24℃, and more preferably 22-23℃; and the time is preferably 2-4 h, further preferably 2.5-3.5 h, and more preferably 2.8-3.2 h.
[0028] In the present application, the temperature treatment in step (3) is sequentially performed by preliminary calcination, reduction calcination, and activation treatment.
[0029] In the present application, the temperature of the preliminary calcination is preferably 250-350℃, further preferably 260-340℃, and more preferably 280-320℃; and the time is preferably 1-2 h, further preferably 1.2-1.8 h, and more preferably 1.4-1.6 h.
[0030] In the present application, the atmosphere of the reduction calcination comprises hydrogen and argon, and the volume fraction of the hydrogen is preferably 5-10%, further preferably 6-9%, and more preferably 7-8%.
[0031] In the present application, the temperature of the reduction calcination is preferably 450-500℃, further preferably 460-490℃, and more preferably 470-480℃; and the time is preferably 2-4 h, further preferably 2.5-3.5 h, and more preferably 2.8-3.2 h.
[0032] In the present application, the temperature of the activation treatment is preferably 270-280℃, further preferably 272-278℃, and more preferably 274-276℃; and the time is preferably 30-60min, further preferably 35-55min, and more preferably 40-50min.
[0033] In the present application, the temperature of the liquid indium in step (4) is preferably 180-185℃, further preferably 181-184℃, and more preferably 182-183℃.
[0034] In the present application, the pulling speed of the coating in step (4) is preferably 2-5mm / s, further preferably 2.5-4.5mm / s, and more preferably 3-4mm / s; and the immersion time is preferably 1-3s, further preferably 1.5-2.5s, and more preferably 1.8-2.3s.
[0035] In the present application, cooling is performed after the coating, and the target temperature of the cooling is preferably 20-30℃, further preferably 22-28℃, and more preferably 24-26℃; and the cooling rate is preferably 30-40℃ / s, further preferably 32-38℃ / s, and more preferably 34-36℃ / s.
[0036] In the present application, the temperature of the hot pressing in step (4) is preferably 140-150℃, further preferably 142-148℃, and more preferably 144-146℃; the pressure is preferably 0.4-0.6MPa, further preferably 0.45-0.55MPa, and more preferably 0.48-0.52MPa; and the time is preferably 30-60s, further preferably 35-55s, and more preferably 40-50s.
[0037] In the present application, the uniformity of the fiber surface is ensured by hot pressing.
[0038] The present application also provides the conductive fiber prepared by the preparation method of the conductive fiber.
[0039] The present application also provides the use of the conductive fiber in flexible electronic devices.
[0040] The technical solutions provided by the present application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present application.
[0041] Example 1
[0042] Take 3.4 g of indium nitrate and 1.8 g of carbon nanotubes, add the indium nitrate and carbon nanotubes to a mixed solution of ethanol (45 mL) and acetylacetone (22 mL), stir at 450 rpm for 20 min to obtain a metal salt solution. Take 1 g of urea and dissolve it in 55 mL of water to obtain an aqueous urea solution, mix 3.5 g of polyvinylpyrrolidone, 26 mL of aqueous urea solution, and 25 mL of ethanol, and stir at 450 rpm for 10 min to obtain a spinning base solution.
[0043] Mix the metal salt solution and the spinning base solution, and perform electrospinning after ultrasonic treatment at a frequency of 26 kHz for 1 h, control the push rate to be 1.1 mL / h, the voltage to be 5.5 kV, the collection distance to be 10 cm, the nozzle inner diameter to be 0.8 mm, and the temperature to be 23°C to obtain fibers, and then place the fibers at 23°C for 3 h.
[0044] Calcine the obtained fibers at 300°C for 1 h, then control the atmosphere to be a mixed gas of argon and hydrogen with a hydrogen volume fraction of 8%, continue to calcine at 480°C for 3 h under the mixed gas condition, then activate the fibers at 275°C for 30 min to obtain a fiber template, immerse the fiber template in liquid indium (182°C) for 2 s at a pulling speed of 3 mm / s, then cool to 25°C at a rate of 35°C / s, and hot-press at 145°C and 0.5 MPa for 50 s, and then naturally cool to obtain a conductive fiber.
[0045] Example 2
[0046] Take 3 g of indium nitrate and 1.6 g of carbon nanotubes, add the indium nitrate and carbon nanotubes to a mixed solution of ethanol (40 mL) and acetylacetone (26 mL), and stir at 420 rpm for 10 min to obtain a metal salt solution. Take 0.5 g of urea and dissolve it in 50 mL of water to obtain an aqueous urea solution, mix 4 g of polyvinylpyrrolidone, 22 mL of aqueous urea solution, and 27 mL of ethanol, and stir at 460 rpm for 15 min to obtain a spinning base solution.
[0047] Mix the metal salt solution and the spinning base solution, and perform electrospinning after ultrasonic treatment at a frequency of 25 kHz for 0.5 h, control the push rate to be 1.4 mL / h, the voltage to be 5.7 kV, the collection distance to be 8 cm, the nozzle inner diameter to be 0.6 mm, and the temperature to be 20°C to obtain fibers, and then place the fibers at 20°C for 2 h.
[0048] The obtained fiber was calcined at 260℃ for 1.5h; then the atmosphere was controlled to be a mixed gas of argon and hydrogen, wherein the volume fraction of hydrogen was 5%, under the mixed gas condition, the temperature was controlled to be 500℃ and the calcination was continued for 3h; then the fiber template was obtained by activation treatment at 274℃ for 40min; the fiber template was immersed in liquid indium (180℃) for dip-coating, the immersion time was 3s and the coating speed was 1mm / s; then the temperature was cooled to 25℃ at a rate of 40℃ / s; the conductive fiber was obtained by hot-pressing at 140℃ and 0.45MPa for 30s and then natural cooling.
[0049] Example 3
[0050] 4.7g of indium nitrate and 1.3g of carbon nanotubes were taken and added into a mixed solution of ethanol (50mL) and acetylacetone (21mL), and a metal salt solution was obtained by stirring at 470rpm for 18min. 1g of urea was dissolved in 50mL of water to obtain an aqueous urea solution, and 3.6g of polyvinylpyrrolidone, 21mL of the aqueous urea solution and 20mL of ethanol were mixed to obtain a spinning base solution by stirring at 460rpm for 20min.
[0051] The metal salt solution and the spinning base solution were mixed, and electrospinning was performed after ultrasonic treatment at a frequency of 30kHz for 0.5h, the pushing rate was controlled to be 1.2mL / h, the voltage was 6kV, the collection distance was 13cm, the inner diameter of the nozzle was 0.7mm, and the temperature was 25℃ to obtain the fiber, and then the fiber was placed at 25℃ for 3h.
[0052] The obtained fiber was calcined at 330℃ for 1.8h; then the atmosphere was controlled to be a mixed gas of argon and hydrogen, wherein the volume fraction of hydrogen was 9%, under the mixed gas condition, the temperature was controlled to be 460℃ and the calcination was continued for 3.5h; then the fiber template was obtained by activation treatment at 276℃ for 40min; the fiber template was immersed in liquid indium (185℃) for dip-coating, the immersion time was 1s and the coating speed was 2mm / s; then the temperature was cooled to 28℃ at a rate of 38℃ / s; the conductive fiber was obtained by hot-pressing at 148℃ and 0.55MPa for 40s and then natural cooling.
[0053] Example 4
[0054] 3.6g of indium nitrate and 2g of carbon nanotubes were taken and added into a mixed solution of ethanol (47mL) and acetylacetone (22mL), and a metal salt solution was obtained by stirring at 450rpm for 20min. 0.9g of urea was dissolved in 55mL of water to obtain an aqueous urea solution, and 4g of polyvinylpyrrolidone, 27mL of the aqueous urea solution and 22mL of ethanol were mixed to obtain a spinning base solution by stirring at 410rpm for 5min.
[0055] The metal salt solution and the spinning base solution were mixed, and electrospinning was carried out after ultrasonic treatment at a frequency of 28 kHz for 0.9 h, with the pushing rate controlled at 1.4 mL / h, the voltage at 5.3 kV, the collection distance at 9 cm, the inner diameter of the nozzle at 1 mm, and the temperature at 25 °C to obtain the fibers, which were then left to stand at 25 °C for 2 h.
[0056] The obtained fibers were calcined at 330 °C for 1 h, and then calcined at 500 °C for 2.5 h under a mixed gas of argon and hydrogen with the volume fraction of hydrogen being 10%, and then activated at 278 °C for 55 min to obtain the fiber template; the fiber template was immersed in liquid indium (184 °C) for 3 s at a pulling speed of 4 mm / s, and then cooled to 25 °C at a rate of 40 °C / s, and then hot-pressed at 146 °C and 0.5 MPa for 60 s, and then naturally cooled to obtain the conductive fibers.
[0057] Example 5
[0058] 5 g of indium nitrate and 1 g of carbon nanotubes were added to a mixed solution of ethanol (44 mL) and acetylacetone (25 mL) to obtain a metal salt solution after stirring at 500 rpm for 30 min. 0.7 g of urea was dissolved in 55 mL of water to obtain an aqueous urea solution, and 3 g of polyvinylpyrrolidone, 29 mL of the aqueous urea solution, and 20 mL of ethanol were mixed to obtain a spinning base solution after stirring at 430 rpm for 10 min.
[0059] The metal salt solution and the spinning base solution were mixed, and electrospinning was carried out after ultrasonic treatment at a frequency of 25 kHz for 0.5 h, with the pushing rate controlled at 1.3 mL / h, the voltage at 5.7 kV, the collection distance at 13 cm, the inner diameter of the nozzle at 0.8 mm, and the temperature at 25 °C to obtain the fibers, which were then left to stand at 25 °C for 4 h.
[0060] The obtained fibers were calcined at 260 °C for 1 h, and then calcined at 500 °C for 2 h under a mixed gas of argon and hydrogen with the volume fraction of hydrogen being 10%, and then activated at 275 °C for 60 min to obtain the fiber template; the fiber template was immersed in liquid indium (182 °C) for 3 s at a pulling speed of 2 mm / s, and then cooled to 25 °C at a rate of 40 °C / s, and then hot-pressed at 150 °C and 0.6 MPa for 40 s, and then naturally cooled to obtain the conductive fibers.
[0061] Comparative Example 1
[0062] Comparative Example 1 and Example 1 differ in that no indium nitrate is added, and the rest of the steps are the same.
[0063] Comparative Example 2
[0064] The difference between Comparative Example 2 and Example 1 is that, after calcination at 480℃ for 3h, no activation treatment and subsequent coating is performed, and the conductive fiber is directly naturally cooled.
[0065] Comparative Example 3
[0066] The difference between Comparative Example 3 and Example 1 is that, the indium in the conductive fiber is replaced by copper, and the rest of the process is the same.
[0067] The fibers prepared in Example 1 and Comparative Example 2 are observed under an electron microscope, the SEM image of the conductive fiber in Example 1 is shown in Figure 1 , and the SEM image of the conductive fiber in Comparative Example 2 is shown in Figure 2 . It can be seen from Figure 1 and Figure 2 that the fiber after activation treatment and coating is uniform in thickness and dense, and can effectively realize the transmission of current.
[0068] The conductive fibers prepared in Examples 1-5 and Comparative Examples are tested for performance, and the tensile properties are tested according to ASTM D3039, the elongation results of Example 1 are shown in Figure 3 , and the elongation results of Comparative Example 2 are shown in Figure 4 . The results are recorded in Table 1.
[0069] Table 1 Performance test results
[0070] From Figure 3 , Figure 4 and the test results in Table 1, it can be seen that the conductive fiber provided by the present application has low surface resistivity and can be used as a current carrier for electronic products. And the elongation reaches 84.3%, which shows that the composite structure of the indium layer and the carbon nanotube can effectively transfer stress and inhibit crack propagation, meeting the requirement of elongation; the tensile strength reaches 62.1MPa, ensuring the daily use strength.
[0071] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.
Claims
1. A method for preparing a conductive fiber, characterized in that: It includes the following steps: (1) mixing indium nitrate, carbon nanotubes, ethanol and acetylacetone to obtain a metal salt solution; (2) mixing polyvinyl pyrrolidone, urea aqueous solution and ethanol to obtain a spinning base solution; (3) mixing the metal salt solution and the spinning base solution, performing electrospinning and temperature treatment to obtain a fiber template; (4) The surface of the fiber template is coated with liquid indium and hot-pressed to obtain the conductive fiber.
2. The method for preparing the conductive fiber according to claim 1, wherein: The mass ratio of indium nitrate to carbon nanotubes in step (1) is 3-5:1-2; The mass volume ratio of indium nitrate, ethanol and acetylacetone in step (1) is 3-5 g:40-50 mL:20-30 mL.
3. The method for preparing the conductive fiber according to claim 2, wherein: The mixing speed in step (1) is 400-500 rpm and the mixing time is 10-30 min.
4. The method for preparing the conductive fiber according to claim 3, wherein: The mass ratio of the polyvinyl pyrrolidone in step (2) to the indium nitrate in step (1) is 3-4:3-5; In step (2), the mass ratio of urea to water in the urea aqueous solution is 0.5-1:50-60.
5. The method for preparing the conductive fiber according to claim 4, wherein: The mass volume ratio of polyvinyl pyrrolidone, urea aqueous solution and ethanol in step (2) is 3~4g:20~30mL:20~30mL.
6. The method for preparing the conductive fiber according to claim 5, wherein: The mixing speed in step (2) is 400-500 rpm and the mixing time is 5-20 min; The mixing frequency in step (3) is 25-30 kHz, and the mixing time is 0.5-1 h.
7. The method for preparing the conductive fiber according to claim 6, wherein: The electrospinning process in step (3) is performed at a rate of 1 to 1.5 mL / h, a voltage of 5 to 6 kV, a collection distance of 5 to 15 cm, a nozzle inner diameter of 0.5 to 1 mm, and a temperature of 20 to 25°C. The temperature treatment in step (3) is a preliminary calcination, reduction calcination and activation treatment carried out in sequence; The temperature of the preliminary calcination is 250-350°C and the time is 1-2 hours; The atmosphere for reduction calcination comprises hydrogen and argon, wherein the volume fraction of hydrogen is 5-10%; The reduction calcination temperature is 450-500°C and the time is 2-4 hours; The activation treatment is performed at a temperature of 270-280° C. and for a time of 30-60 minutes.
8. The method for preparing the conductive fiber according to claim 7, wherein: The temperature of the liquid indium in step (4) is 180-185°C; The coating pulling speed in step (4) is 2-5 mm / s, and the immersion time is 1-3 s; The hot pressing in step (4) is performed at a temperature of 140-150° C., a pressure of 0.4-0.6 MPa, and a time of 30-60 seconds.
9. The conductive fiber prepared by the method for preparing the conductive fiber according to any one of claims 1 to 8.
10. Use of the conductive fiber according to claim 9 in flexible electronic devices.