Laser fabrication method and application of self-supporting PEDOT / rGO porous electrode

Abstract

The application relates to the technical field of environmental functional materials, and discloses a laser preparation method and application of a self-supporting PEDOT / rGO porous electrode, which comprises the following steps: mixing a partially reduced graphene oxide water dispersion liquid and a PEDOT:PSS water dispersion liquid to obtain a PEDOT / rGO composite precursor liquid; processing the precursor liquid by using a laser direct writing system, in-situ reduction and cross-linking are induced by photothermal effect to form a three-dimensional structure material; and after cleaning and freeze-drying, a self-supporting PEDOT / rGO porous electrode is obtained. The application also relates to the application of the electrode in the preparation of energy storage devices. The method has a short technological process, integrates material synthesis and three-dimensional forming in one step, and can realize the graphic preparation of the electrode without a current collector. The prepared electrode does not contain a binder, has self-supporting characteristics and a three-dimensional porous structure, which not only simplifies the assembly process of the energy storage device, but also is favorable for improving the electrochemical performance of the device, such as the rate performance and specific capacitance.

Description

Technical Field

[0001] This invention relates to the field of environmental functional materials technology, specifically to a laser fabrication method and application of self-supporting PEDOT / rGO porous electrodes. Background Technology

[0002] With the rapid development of industries such as portable electronic devices and electric vehicles, the market demand for high-performance energy storage devices such as supercapacitors and batteries is increasing. As a core component of energy storage devices, the structure and performance of electrode materials directly determine the energy density, power density, and cycle life of the devices.

[0003] To improve electrode performance, researchers are dedicated to developing composite materials that combine high conductivity, large specific surface area, and excellent electrochemical activity. Among these, composite materials composed of conductive polymers (such as poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, i.e., PEDOT:PSS) and graphene materials (such as reduced graphene oxide, rGO) have attracted much attention due to their synergistic advantages. PEDOT:PSS exhibits high intrinsic conductivity and pseudocapacitive properties, while graphene provides an excellent conductive network, a huge theoretical specific surface area, and stable mechanical support.

[0004] However, effectively integrating the advantages of these two materials to construct a high-performance macroscopic electrode still faces challenges in its fabrication methods. Traditional composite electrode fabrication typically requires mixing pre-synthesized active material powder with inactive polymer binders and conductive additives to form a slurry, which is then coated onto a metal current collector. The binder introduced in this process not only fails to contribute capacitance but also increases the internal resistance of the electrode, reducing the overall energy density. Simultaneously, the interfacial bonding between the active material layer and the current collector is weak, leading to delamination during long-term charge-discharge cycles and affecting the device's cycle stability.

[0005] To address the problems caused by binders, several self-supporting electrode fabrication methods have been developed, such as vacuum filtration or hydrothermal methods. However, these methods typically produce dense two-dimensional thin-film structures with limited internal ion transport channels, hindering rapid electrolyte ion transport and thus limiting electrode performance at high rates. Furthermore, for the applications of micro-energy storage devices, most existing fabrication techniques struggle to achieve precise patterning control of the electrode structure. Patterning requires complex subsequent processing steps such as photolithography, increasing process complexity and cost.

[0006] Therefore, developing a fabrication technology that can construct composite electrodes with three-dimensional porous structures and customizable patterns in a one-step, binder-free manner is of great significance for promoting the development of high-performance energy storage devices. Summary of the Invention

[0007] The technical problem solved by this invention is that existing methods for preparing conductive polymer / graphene composite electrodes are usually complex, time-consuming, require the addition of non-active binders, and are difficult to achieve precise construction of micro-area patterning and three-dimensional porous structures.

[0008] To address the above problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a laser fabrication method for a self-supporting PEDOT / rGO porous electrode.

[0009] The method includes the following steps: mixing a partially reduced graphene oxide aqueous dispersion with a PEDOT:PSS aqueous dispersion to obtain a PEDOT / rGO composite precursor solution; treating the PEDOT / rGO composite precursor solution with a laser direct writing system to induce in-situ reduction and cross-linking to form a three-dimensional structural material through photothermal action; cleaning the three-dimensional structural material to remove unreacted precursors; and freeze-drying the cleaned three-dimensional structural material to obtain the self-supporting PEDOT / rGO porous electrode.

[0010] By adopting the above technical solution, this invention utilizes laser direct writing technology to construct an integrated, self-supporting porous electrode. Its core innovative principle is rooted in the complex interaction process between the laser and the precursor liquid. This process begins with the construction of the precursor liquid, in which partially reduced graphene oxide (rGO) carrying a negative charge and a PEDOT:PSS aqueous dispersion (where PSS is negatively charged and PEDOT is positively charged) form a uniform and stable composite colloidal system through electrostatic attraction.

[0011] When a high-energy-density laser beam is focused onto the precursor liquid, its energy is efficiently absorbed and rapidly converted into localized high temperatures, i.e., the photothermal effect. This instantaneous local heating triggers two key, almost simultaneous physicochemical transformations: firstly, it induces the decomposition and removal of oxygen-containing functional groups on the rGO surface, achieving further in-situ reduction of the graphene framework and thus improving conductivity; secondly, the high temperature promotes the cross-linking reaction between the PEDOT:PSS molecular chains and rGO sheets, as well as the curing of PEDOT:PSS itself. In this process, PEDOT:PSS not only constructs a conductive network but also acts as a connection point and support in three-dimensional space, effectively preventing the recombination of rGO sheets.

[0012] Finally, by freeze-drying and sublimation to remove moisture from the material, an interconnected three-dimensional porous structure is fully preserved. Therefore, the method of this invention, through a one-step laser direct writing process, synergistically achieves in-situ deep reduction of rGO, cross-linking and molding of composite materials, and construction of a three-dimensional porous structure. The preparation process is simple, rapid, and controllable. The resulting electrode has self-supporting properties without any binder and possesses a continuous conductive network and abundant active sites.

[0013] Preferably, in the step of mixing partially reduced graphene oxide aqueous dispersion and PEDOT:PSS aqueous dispersion to obtain PEDOT / rGO composite precursor solution, the volume ratio of the partially reduced graphene oxide aqueous dispersion to the PEDOT:PSS aqueous dispersion is (1-2):1. By adjusting the ratio of the two components, the conductivity and mechanical stability of the final electrode can be optimized, thereby achieving the regulation of electrochemical performance.

[0014] Preferably, the step of obtaining the PEDOT / rGO composite precursor liquid further includes ultrasonic treatment of the mixed liquid for 30-60 minutes. Ultrasonic treatment utilizes cavitation to further disperse any small aggregates present in the liquid, ensuring more uniform dispersion and contact between the rGO sheets and PEDOT:PSS molecules, thus guaranteeing the formation of a homogeneous three-dimensional network structure.

[0015] Preferably, the partially reduced graphene oxide aqueous dispersion is prepared by the following method: a hydrothermal reaction of a graphene oxide aqueous dispersion with a concentration of 1-5 mg / mL is carried out at a temperature of 40-80°C for 5-12 hours.

[0016] More preferably, the hydrothermal reaction conditions are as follows: using a graphene oxide aqueous dispersion with a concentration of 2 mg / mL, reacting at 60°C for 8 hours. By pre-reducing the graphene oxide through mild hydrothermal treatment, some unstable oxygen-containing functional groups can be removed, improving its basic conductivity, while retaining a certain amount of functional groups to maintain its dispersibility in water and provide reaction sites for subsequent laser crosslinking.

[0017] Preferably, in the step of processing using the laser direct writing system, the laser parameters used are: wavelength of 450-532nm and power of 1.35-5W. Laser wavelengths within this range can be effectively absorbed by the precursor solution, while the power ensures sufficient reaction while avoiding excessive damage to the formed structure.

[0018] Preferably, the laser direct writing process is performed in an inert gas atmosphere. Laser processing under an inert gas (such as argon) protection effectively prevents oxidation of the material at high temperatures, ensuring the chemical purity and conductivity of the electrode material.

[0019] Secondly, the present invention provides a self-supporting PEDOT / rGO porous electrode.

[0020] This self-supporting PEDOT / rGO porous electrode is composed of partially reduced graphene oxide and PEDOT:PSS composite; and has a three-dimensional porous structure and an integrated structure without binders.

[0021] By employing the above technical solution, the electrode obtained by this invention exhibits superior performance directly stemming from its highly integrated physical architecture. Its three-dimensional porous nature provides a vast active specific surface area for charge storage or ion adsorption. Simultaneously, the interconnected pore network constitutes a highly efficient ion transport channel, which is crucial for rapid electrochemical response.

[0022] More importantly, this electrode is an integrated structure without binders. This means that the active material of the electrode itself is a conductive framework and mechanical support, eliminating the interfacial resistance introduced by binders and enabling efficient electron transport throughout the entire electrode. This structure is formed by the synergistic effect of partially reduced graphene oxide and PEDOT:PSS. The former serves as a highly conductive framework, while the latter acts as a conductive polymer that fills and connects the components, together constructing a continuous electron transport network that runs through the entire electrode and endowing the electrode with good mechanical flexibility.

[0023] Thirdly, the present invention provides an application of a self-supporting PEDOT / rGO porous electrode.

[0024] The application lies in using the aforementioned self-supporting PEDOT / rGO porous electrode to fabricate energy storage devices.

[0025] By adopting the above technical solutions, the electrode's own structural advantages, such as high conductivity, large specific surface area, and efficient ion transport channels, give it excellent application potential in the energy storage field, where material performance requirements are stringent.

[0026] Preferably, the energy storage device is a capacitive deionization device or a supercapacitor. For example, when the electrode is applied to a supercapacitor, its highly conductive network and high specific surface area enable rapid charge storage and release, exhibiting high specific capacitance and high rate performance. In the application scenario of a capacitive deionization device, its abundant pore structure can efficiently adsorb ions in water, thereby achieving water purification.

[0027] This invention provides a laser fabrication method and application for self-supporting PEDOT / rGO porous electrodes. It offers the following advantages: 1. This invention utilizes a laser direct-writing system to directly act on the liquid-phase precursor liquid, integrating material reduction, cross-linking, and three-dimensional molding into a single step, thus shortening the fabrication cycle. Furthermore, since the laser path can be precisely controlled by a computer program, micro-area and patterned electrode fabrication can be achieved without expensive photomasks, improving fabrication efficiency and the flexibility of structural design.

[0028] 2. The electrode prepared by this invention exhibits excellent electrochemical performance. The laser-induced three-dimensional porous network structure increases the contact area between the electrode and the electrolyte, and provides a low-impedance transport channel for the diffusion of electrolyte ions. Simultaneously, the electrode prepared by this method contains no non-conductive binders, ensuring good internal electronic conductivity between the active material particles. These two factors work synergistically to effectively improve the rate performance and specific capacitance of the electrode.

[0029] 3. The electrode obtained by this invention has self-supporting properties, simplifying the assembly process of energy storage devices. This electrode integrates the functions of an active material and a current collector, and can be directly used as a working electrode, eliminating the steps of coating, drying, rolling, and connection to the metal current collector in traditional processes. This not only reduces the contact resistance of the device but also facilitates the lightweighting and miniaturization of energy storage devices. Attached Figure Description

[0030] Figure 1 This is a comparison diagram of the macroscopic electrical properties of the electrodes obtained in Example 1 and Comparative Example 3 of the present invention; Figure 2 This is an indirect characterization diagram of the porous characteristics of the electrodes in the embodiments and comparative examples of the present invention; Figure 3 The following is a line graph showing the basic electrochemical specific capacitance of the embodiments and comparative examples of the present invention; Figure 4 Electrochemical impedance Nyquist plots for embodiments and comparative examples of the present invention; Figure 5 This is a comparison chart of the specific capacitance and rate performance of the embodiments and comparative examples of the present invention; Figure 6 The images show the adsorption isotherms of PFOA on the electrodes of the embodiments and comparative examples of this invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0033] Graphene oxide aqueous dispersion: a colloidal solution containing graphene oxide (GO, CAS No.: 1034343-98-0), the structure of which is composed of oxygen-containing functional groups such as hydroxyl, epoxy and carboxyl groups covalently linked to a carbon atom skeleton, and the concentration of solid content used is 0.5-5 mg / mL.

[0034] Poly(3,4-ethylenedioxythiophene): An aqueous dispersion of a complex composed of the conductive polymer poly(3,4-ethylenedioxythiophene) and the water-soluble polymer poly(styrene sulfonate) (PEDOT:PSS, CAS No.: 155090-83-8), which is a dark blue liquid.

[0035] Argon (Ar, CAS No.: 7440-37-1), with a purity of 99.999%, is used as a protective gas.

[0036] Perfluorooctanoic acid (PFOA, CAS No.: 335-67-1), chemical formula C8HF15O2, analytical grade, is used as a target pollutant for adsorption performance testing.

[0037] Ultrapure water: resistivity not less than 18.2 MΩ·cm (25℃), used as a solvent and cleaning agent.

[0038] Preparation Examples 1-3: Preparation Example 1: This preparation example provides a method for preparing a partially reduced graphene oxide aqueous dispersion (rGO-1), the specific steps of which are as follows: Take 50 mL of a 1 mg / mL aqueous dispersion of graphene oxide and place it in a 100 mL stainless steel reactor lined with polytetrafluoroethylene. After sealing, place the reactor in a drying oven and carry out a hydrothermal reaction at a constant temperature of 40°C for 5 hours. After the reaction is complete, allow the reactor to cool naturally to room temperature, remove the liner, and obtain a partially reduced aqueous dispersion of graphene oxide (rGO-1) for later use.

[0039] Preparation Example 2: This preparation example provides a method for preparing a partially reduced graphene oxide aqueous dispersion (rGO-2), the specific steps of which are as follows: Take 50 mL of a 2 mg / mL aqueous dispersion of graphene oxide and place it in a 100 mL stainless steel reactor lined with polytetrafluoroethylene. After sealing, place the reactor in a drying oven and carry out a hydrothermal reaction at a constant temperature of 60°C for 8 hours. After the reaction is complete, allow the reactor to cool naturally to room temperature, remove the liner, and obtain a partially reduced aqueous dispersion of graphene oxide (rGO-2) for later use.

[0040] Preparation Example 3: This preparation example provides a method for preparing a partially reduced graphene oxide aqueous dispersion (rGO-3), the specific steps of which are as follows: Take 50 mL of a 5 mg / mL aqueous dispersion of graphene oxide and place it in a 100 mL stainless steel reactor lined with polytetrafluoroethylene. After sealing, place the reactor in a drying oven and carry out a hydrothermal reaction at a constant temperature of 80°C for 12 hours. After the reaction is complete, allow the reactor to cool naturally to room temperature, remove the liner, and obtain a partially reduced aqueous dispersion of graphene oxide (rGO-3) for later use.

[0041] Examples 1-6: Example 1: This embodiment provides a method for fabricating a self-supporting PEDOT / rGO porous electrode, including the following steps: 1. Take 30 mL of the partially reduced graphene oxide aqueous dispersion (rGO-2) prepared in Preparation Example 2 and mix it with 30 mL of PEDOT:PSS aqueous dispersion (volume ratio of 1:1). Place the mixture in an ultrasonic cleaner for 30 minutes to obtain a uniform and stable PEDOT / rGO composite precursor solution.

[0042] 2. The composite precursor solution obtained in step 1 was placed in a culture dish and processed using a laser direct writing system. The laser parameters were set as follows: wavelength 450 nm, power 3 W, and scanning speed 0.5 s / cm. The processing was carried out under an argon atmosphere.

[0043] 3. After the laser treatment is completed, the obtained three-dimensional structural material is removed from the remaining liquid and repeatedly washed with ultrapure water to remove unreacted precursors.

[0044] 4. Place the cleaned material in a freeze dryer and freeze dry for 24 hours to obtain a self-supporting PEDOT / rGO porous electrode.

[0045] Example 2: This embodiment provides a method for fabricating a self-supporting PEDOT / rGO porous electrode, including the following steps: 1. Take 40 mL of the partially reduced graphene oxide aqueous dispersion (rGO-2) prepared in Preparation Example 2 and mix it with 20 mL of PEDOT:PSS aqueous dispersion (volume ratio of 2:1). Place the mixture in an ultrasonic cleaner for 30 minutes to obtain a uniform and stable PEDOT / rGO composite precursor solution.

[0046] 2. The composite precursor solution obtained in step 1 was placed in a culture dish and processed using a laser direct writing system. The laser parameters were set as follows: wavelength 450 nm, power 3 W, and scanning speed 0.5 s / cm. The processing was carried out under an argon atmosphere.

[0047] 3. After the laser treatment is completed, the obtained three-dimensional structural material is removed from the remaining liquid and repeatedly washed with ultrapure water.

[0048] 4. Place the cleaned material in a freeze dryer and freeze dry for 24 hours to obtain a self-supporting PEDOT / rGO porous electrode.

[0049] Example 3: This example provides a method for fabricating a self-supporting PEDOT / rGO porous electrode, including the following steps: 1. Take 30 mL of the partially reduced graphene oxide aqueous dispersion (rGO-2) prepared in Preparation Example 2 and mix it with 30 mL of PEDOT:PSS aqueous dispersion (volume ratio of 1:1). Place the mixture in an ultrasonic cleaner for 30 minutes to obtain a uniform and stable PEDOT / rGO composite precursor solution.

[0050] 2. The composite precursor solution obtained in step 1 was placed in a culture dish and processed using a laser direct writing system. The laser parameters were set as follows: wavelength 450 nm, power 1.35 W, and scanning speed 0.5 s / cm. The processing was carried out under an argon atmosphere.

[0051] 3. After the laser treatment is completed, the obtained three-dimensional structural material is removed from the remaining liquid and repeatedly washed with ultrapure water.

[0052] 4. Place the cleaned material in a freeze dryer and freeze dry for 24 hours to obtain a self-supporting PEDOT / rGO porous electrode.

[0053] Example 4: This example provides a method for fabricating a self-supporting PEDOT / rGO porous electrode, including the following steps: 1. Take 30 mL of the partially reduced graphene oxide aqueous dispersion (rGO-2) prepared in Preparation Example 2 and mix it with 30 mL of PEDOT:PSS aqueous dispersion (volume ratio of 1:1). Place the mixture in an ultrasonic cleaner for 30 minutes to obtain a uniform and stable PEDOT / rGO composite precursor solution.

[0054] 2. The composite precursor solution obtained in step 1 was placed in a culture dish and processed using a laser direct writing system. The laser parameters were set as follows: wavelength 450 nm, power 5 W, and scanning speed 0.5 s / cm. The process was carried out under an argon atmosphere.

[0055] 3. After the laser treatment is completed, the obtained three-dimensional structural material is removed from the remaining liquid and repeatedly washed with ultrapure water.

[0056] 4. Place the cleaned material in a freeze dryer and freeze dry for 24 hours to obtain a self-supporting PEDOT / rGO porous electrode.

[0057] Example 5: This embodiment provides a method for fabricating a self-supporting PEDOT / rGO porous electrode, including the following steps: 1. Take 30 mL of the partially reduced graphene oxide aqueous dispersion (rGO-1) prepared in Preparation Example 1 and mix it with 30 mL of PEDOT:PSS aqueous dispersion (volume ratio of 1:1). Place the mixture in an ultrasonic cleaner for 30 minutes to obtain a uniform and stable PEDOT / rGO composite precursor solution.

[0058] 2. The composite precursor solution obtained in step 1 was placed in a culture dish and processed using a laser direct writing system. The laser parameters were set as follows: wavelength 450 nm, power 3 W, and scanning speed 0.5 s / cm. The processing was carried out under an argon atmosphere.

[0059] 3. After the laser treatment is completed, the obtained three-dimensional structural material is removed from the remaining liquid and repeatedly washed with ultrapure water.

[0060] 4. Place the cleaned material in a freeze dryer and freeze dry for 24 hours to obtain a self-supporting PEDOT / rGO porous electrode.

[0061] Example 6: This embodiment provides a method for fabricating a self-supporting PEDOT / rGO porous electrode, including the following steps: 1. Take 30 mL of the partially reduced graphene oxide aqueous dispersion (rGO-2) prepared in Preparation Example 2 and mix it with 30 mL of PEDOT:PSS aqueous dispersion (volume ratio of 1:1). Place the mixture in an ultrasonic cleaner for 30 minutes to obtain a uniform and stable PEDOT / rGO composite precursor solution.

[0062] 2. The composite precursor solution obtained in step 1 was placed in a culture dish and processed using a laser direct writing system. The laser parameters were set as follows: wavelength 532 nm, power 3 W, and scanning speed 0.5 s / cm. The process was carried out under an argon atmosphere.

[0063] 3. After the laser treatment is completed, the obtained three-dimensional structural material is removed from the remaining liquid and repeatedly washed with ultrapure water.

[0064] 4. Place the cleaned material in a freeze dryer and freeze dry for 24 hours to obtain a self-supporting PEDOT / rGO porous electrode.

[0065] Comparative Examples 1-4: Comparative Example 1: Compared with Example 1, the difference is that this comparative example uses a traditional coating method to prepare the electrode. Specifically, the PEDOT / rGO composite precursor liquid obtained in step 1 of Example 1 is freeze-dried to obtain a composite powder. The powder is mixed with polyvinylidene fluoride (PVDF) binder and acetylene black conductive agent at a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added to form a uniform slurry, which is then coated onto a nickel foam current collector. After vacuum drying and pressing, the electrode is obtained.

[0066] Comparative Example 2: Compared with Example 1, the difference is that the laser direct writing process in step 2 is not performed. Instead, the PEDOT / rGO composite precursor solution obtained in step 1 is directly subjected to the freeze-drying process in step 4.

[0067] Comparative Example 3: Compared with Example 1, the difference is that PEDOT:PSS aqueous dispersion is not used. In step 1, only the partially reduced graphene oxide aqueous dispersion (rGO-2) prepared in Preparation Example 2 is used, and the pure rGO electrode is prepared using the same laser treatment and freeze-drying steps as in Example 1.

[0068] Comparative Example 4: Compared with Example 1, the difference is that the laser direct writing process in step 2 is not performed. Instead, the PEDOT / rGO composite precursor liquid obtained in step 1 is placed in a mold and subjected to overall heat treatment in an oven at 180°C for 2 hours under an argon atmosphere, followed by cleaning and freeze drying.

[0069] Test Examples 1-5: Test Example 1: Electrode Macroscopic Physical Properties Test.

[0070] This test evaluates the self-supporting mechanical properties and macroscopic conductivity of the electrode prepared by the method of this invention, in order to verify the feasibility of the technical solution of this invention.

[0071] Take the dried samples prepared in Example 1, Comparative Example 2, and Comparative Example 3. First, use tweezers to hold the samples and perform slight bending and movement to observe whether they maintain their macroscopic structural integrity. Then, immerse the samples in a beaker containing ultrapure water and let them stand for 5 minutes to observe whether they disintegrate while immersed.

[0072] For samples that passed the mechanical integrity evaluation in step 1, their sheet resistance was measured at room temperature using a four-probe tester (RTS-8 type). To ensure data representativeness, five points were measured at different locations for each sample, and the average value was taken. Before measurement, the geometric dimensions of each sample were measured using vernier calipers. Conductivity (σ) was calculated according to the formula... Calculation, where The resistance of the thin film is (Ω / sq). The thickness of the sample is in meters (m).

[0073] Table 1. Comparison of macroscopic physical properties between the examples and comparative samples Reference Appendix Figure 1 , Figure 1 In the figure, the left vertical axis represents conductivity (S / m), which is represented by gray bars; the right vertical axis represents sheet resistance (Ω / sq), which is represented by black dots and lines. This figure visually compares the difference in conductivity between the PEDOT / rGO composite electrode prepared by the method of this invention and the pure rGO electrode without PEDOT:PSS.

[0074] In summary, based on the data in Table 1, the mechanical stability of the electrode is a prerequisite for its application as a standalone device. The electrode prepared in Example 1 maintained its structural integrity in both dry and wet states, confirming that the laser direct writing process can transform liquid-phase precursors into a three-dimensional solid framework with cross-linking strength through a localized photothermal effect. The sample in Comparative Example 2, lacking a laser-induced curing process, produced a loose aggregate lacking mechanical strength and unable to be molded. This comparative result demonstrates the importance of the laser-induced curing process for forming mechanically stable structures.

[0075] The conductivity of an electrode affects its charge transport efficiency in electrochemical applications. The electrical performance data in Table 1 further demonstrate the technical features of this invention. The electrode in Example 1 achieved a conductivity of 1042.5 S / m, a level favorable for charge transport within the electrode mass. The results of Comparative Example 3 are noteworthy; after removing the PEDOT:PSS component, the conductivity of the resulting pure rGO electrode decreased to 439.4 S / m. This phenomenon reveals the synergistic effect of the two components in the scheme. PEDOT:PSS not only provides an additional charge transport path as a conductive component, but its polymer chains also act as physical spacers under laser thermal effects, suppressing the stacking of rGO sheets due to thermal reduction, thereby maintaining a three-dimensional network structure conducive to electron transport. In summary, these test results demonstrate that the scheme of this invention can prepare a self-supporting conductive electrode, and the experimental data support its technical concept of laser-induced molding and the synergistic effect of the two components.

[0076] Test Example 2: Indirect Characterization of Electrode Porosity This test aims to evaluate the porosity structure characteristics of the prepared electrodes, thereby verifying the actual effect of the laser-induced pore formation mechanism. The test objects used cover the dried samples of Example 1, Example 2, Comparative Example 3 and Comparative Example 4.

[0077] For each group of dried samples, the dimensions of length, width, and thickness were measured using a vernier caliper with an accuracy of 0.01 mm, and the apparent volume was calculated. Simultaneously, the dry weight data was obtained using a microbalance with an accuracy of 0.1 mg. The ratio of dry weight to apparent volume is the apparent density of the sample. To reduce random errors during the measurement process, three independent individuals from each sample group were randomly selected for parallel testing, and the average value was taken.

[0078] The sample, after its apparent density was measured, was transferred to a glass petri dish containing anhydrous ethanol, ensuring that the entire sample was submerged below the liquid surface. The sample was then left to stand at room temperature for 12 hours to allow the solvent to penetrate into the internal pores of the material.

[0079] After the soaking process is completed, the sample is removed with flat-tipped tweezers and quickly placed on lint-free paper. It is left for approximately 3 seconds to remove excess free liquid from the surface, and then transferred to a microbalance to weigh its wet weight. The solvent adsorption rate is obtained by calculating the difference between the wet and dry weights and dividing by the dry weight.

[0080] Table 2. Indirect characterization data of porous properties of the examples and comparative samples Reference Appendix Figure 2 , Figure 2 In the diagram, the solid line, associated with the square marker on the left vertical axis, reflects the changes in the apparent density values ​​of Example 1, Example 2, Comparative Example 3, and Comparative Example 4; the dashed line, associated with the circular marker on the right vertical axis, shows the solvent adsorption rate of the four corresponding samples.

[0081] In summary, based on the data provided in Table 2, the various embodiments and comparative examples exhibit different numerical distributions in terms of apparent density and solvent adsorption rate. These changes in macroscopic physical parameters reflect the evolution of the internal pore structure of the material.

[0082] The apparent densities of Examples 1 and 2 are in the lower range, corresponding to a relatively increased solvent adsorption capacity. This data performance is consistent with the physical process of solvent vaporization caused by photothermal effect in laser direct writing. After absorbing energy, the precursor liquid locally heats up, the liquid phase transforms into a gas phase and escapes, forming physical channels in the solidified cross-linked framework.

[0083] The formation state of the aforementioned pore structure was further explained when comparing different heat treatment methods. Comparative Example 4 used conventional overall heat treatment. Due to the slow overall temperature rise, the material skeleton underwent volume shrinkage during the liquid phase volatilization due to capillary force.

[0084] The measured apparent density was more than ten times that of Example 1, and the corresponding solvent adsorption amount decreased significantly. This difference reflects the role of the local rapid thermal deposition pathway in maintaining the three-dimensional porous network.

[0085] Besides the processing technology, the interaction between material components constitutes another factor affecting the pore structure. Comparative Example 3, examining single components, shows that pure carbon materials treated with the same laser process still exhibit an increasing apparent density, indicating that the space for liquid to be contained within the pores is compressed.

[0086] Based on research and observations of conventional carbon-based materials, sheet-like graphene, after reduction and exfoliation, is prone to spatial physical stacking driven by interlayer forces. This scheme introduces poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate). While the molecular chains of this substance participate in the construction of the conductive network, their physical volume occupies part of the interlayer gaps, creating spatial obstacles to the re-aggregation of graphene sheets and effectively supporting the porous framework. Overall test data are consistent with the designed mechanism of rapid laser-induced pore formation and multi-component spatial support.

[0087] Test Example 3: Verification of basic electrochemical double-layer capacitance behavior.

[0088] This test evaluates the charge storage capacity and kinetic behavior of the electrode prepared by the present invention in an electrolyte environment. The test subjects include the electrode samples of Example 1, Comparative Example 1 and Comparative Example 3.

[0089] A standard three-electrode testing system was constructed, using a 0.5 mol / L sodium sulfate aqueous solution as the test electrolyte. A platinum wire electrode was selected as the counter electrode, and a saturated calomel electrode was selected as the reference electrode. The self-supporting electrodes prepared in Example 1 and Comparative Example 3 were cut into 1 cm × 1 cm sizes and directly connected to the working electrode clamp; for Comparative Example 1, a nickel foam current collector coated with composite material was directly clamped as the working electrode.

[0090] Connect the assembled three-electrode system to the electrochemical workstation (CHI760E model). Set the test system to run using cyclic voltammetry within a potential window of 0V to 0.8V.

[0091] Adjust the parameters of the electrochemical workstation and record the cyclic voltammetry curves of each sample at scan rates of 10 mV / s, 20 mV / s, 50 mV / s, and 100 mV / s, respectively. After the test, according to the formula... Calculate the mass-to-capacitance ratio, where In response to current, Potential, For scan rate, For the mass of the electrode active material, This represents the width of the potential window.

[0092] Table 3. Specific capacitance data of the examples and comparative examples at different scan rates Reference Appendix Figure 3, Figure 3 The horizontal axis represents the scan rate (mV / s) set in the test, and the vertical axis represents the specific capacitance (F / g) calculated based on the cyclic voltammetry curve. The solid line, dashed line, and dotted line in the figure respectively show the attenuation law of the electrode performance of Example 1, Comparative Example 1, and Comparative Example 3 as the scan rate increases.

[0093] Summary: According to the data in Table 3, the specific capacitance values ​​of all three samples showed a physical law of decreasing with increasing scan rate. At a low scan rate of 10 mV / s, the hydrated ions in the electrolyte system had sufficient diffusion time to penetrate deep into the pores of the material and complete the charge adsorption at the double-layer interface. Example 1, under these conditions, measured a specific capacitance of 184.2 F / g, which was at an advantageous level in the control group. Comparative Example 1, using a conventional coating process, showed a lower initial capacitance (121.4 F / g), and this difference reflects the influence of the preparation method on the interfacial activity of the material. The polyvinylidene fluoride binder added during conventional pulping is an electrochemically inert substance. After curing, it typically coats part of the carbon material surface. This physical shielding reduces the accessible effective specific surface area and interferes with the initial charge accumulation process.

[0094] The capacity difference under low-speed conditions mainly stems from the exposure of the effective specific surface area. However, as the testing rate increases, the rationality of the internal ion transport channel configuration becomes the decisive factor affecting performance. The system's kinetic requirements for ion migration increase with the rate of change of electric field. At the 100 mV / s testing node, the specific capacitance of Comparative Example 1 drops to 34.1 F / g, indicating that the porosity of the traditional dense coating is too high, limiting the rapid ion response. Comparative Example 3, lacking the conductive polymer component, also shows a decrease in capacity from 145.6 F / g to 48.9 F / g. A common phenomenon in the conventional electrochemical evaluation of pure reduced graphene oxide materials is that the sheet structure is prone to secondary aggregation driven by interlayer van der Waals forces after being removed from the hydrothermal reaction solvent. This aggregation tendency leads to the formation of non-connected closed pores or elongated microporous structures, making it difficult for ions to overcome interlayer steric hindrance during charge-discharge cycles.

[0095] Corresponding to the performance degradation of the aforementioned comparative examples, Example 1 still retained a capacity of 105.3 F / g under a high-frequency alternating electric field of 100 mV / s. This test result verifies the pore network state of the component co-evolution in this scheme. Laser treatment induces in-situ vaporization of the liquid phase to generate large pores, and with the interpenetration and cross-linking of polymer macromolecular chains, the material maintains the interlayer spacing of micro-layers on a macroscopic level. This self-supporting framework structure containing hierarchical channels shortens the overall diffusion path of ions and reduces mass transfer resistance. The test data, from a kinetic perspective, confirms the theoretical presupposition of this invention regarding the optimization of interfacial charge exchange configuration.

[0096] Test Example 4: Comparative Analysis of Electrode Internal Resistance and Charge Transfer Dynamics.

[0097] This test aims to evaluate the ohmic resistance within the electrode system and the charge transfer process at the solid-liquid interface, and to verify the mass transfer performance of the self-supporting porous structure through quantitative data of impedance characteristics. The experimental subjects include the electrode samples from Example 1, Comparative Example 1, and Comparative Example 3.

[0098] A three-electrode electrochemical test cell was constructed, with a 0.5 mol / L sodium sulfate aqueous solution as the electrolyte. The auxiliary electrode was a platinum wire electrode, and the reference electrode was a saturated calomel electrode. The self-supporting samples from Example 1 and Comparative Example 3 were cut to specific dimensions and fixed with clamps to serve as working electrodes; the nickel foam substrate loaded with active material from Comparative Example 1 was used as the working electrode.

[0099] Connect the three electrodes to the CHI760E electrochemical workstation. Before testing, let the electrodes stand in the electrolyte for 30 minutes until the open circuit potential stabilizes before starting the measurement.

[0100] Set the AC impedance test parameters in the electrochemical workstation software. Set the initial potential to open circuit potential, the AC excitation signal amplitude to 5mV, and the scan frequency range to 100kHz to 0.01Hz.

[0101] Run the impedance measurement program and record the real and imaginary impedance data of the system. After the test, use ZView software to perform equivalent circuit fitting on the measured Nyquist plot. Read the equivalent series resistance (Rs) by the intercept of the curve in the high-frequency region with the coordinate axis, and obtain the charge transfer resistance (Rct) by the diameter of the semicircle in the mid-to-high frequency region.

[0102] Table 4. Electrochemical impedance spectroscopy fitting parameters for the examples and comparative examples Reference Appendix Figure 4 , Figure 4 In the figure, the horizontal axis Z' represents the real part of the AC impedance, and the vertical axis -Z'' represents the negative value of the imaginary part of the AC impedance. The curve in the figure consists of a high-frequency region (a semicircle near the origin of the coordinate system) and a low-frequency region (a diagonal line extending to the upper right). The solid line, dashed line, and dotted line respectively depict the evolution of the interface impedance of Example 1, Comparative Example 1, and Comparative Example 3 under AC signal excitation at different frequencies.

[0103] In summary, based on the data in Table 4, the high-frequency intercept and the mid-to-high-frequency semicircle diameter of the electrochemical impedance spectroscopy reflect the equivalent series resistance and charge transfer resistance of the system, respectively. The equivalent series resistance of Example 1 is 1.27 ohms. This low bulk resistance is attributed to the excellent electronic conductivity of the self-supporting three-dimensional network. In contrast, the binder introduced in Comparative Example 1 and the interfacial contact issues with the current collector increase its equivalent series resistance to 3.62 ohms. This increase is attributed to the additional resistance imposed by the inactive components along the electron transport path.

[0104] Differences in ohmic internal resistance constitute the distinction in fundamental transport conditions, while the pore connectivity within the material further influences the kinetic behavior of electrolyte ions. Example 1 exhibits a charge transfer resistance of 0.83 ohms, demonstrating a low interfacial mass transfer barrier. Comparative Example 1, using a conventional coating, shows an increased charge transfer resistance of 4.15 ohms. This is attributed to the physical encapsulation of some mesopores and micropores by the binder during curing, which reduces the electrochemically active surface area exposed to the electrolyte.

[0105] Comparative Example 3, which did not contain any polymer, also exhibited a charge transfer resistance of 2.88 ohms. In the liquid-phase removal stage, the pure reduced graphene oxide system experienced stacking between layers due to van der Waals forces. This stacking not only shielded the internal active sites but also prolonged the physical path for solvated ions to enter the deep pores.

[0106] The impedance parameters of Example 1 validate the structural mechanism expected in this design. The laser-induced in-situ crosslinking process, combined with the spatial support of the polymer molecular chains, constructs a continuous electron transport framework and maintains ion diffusion channels with hierarchical gradients. This structure avoids the conduction barriers caused by insulating additives in traditional processes, while simultaneously suppressing the physical aggregation of two-dimensional nanomaterials, thus improving the charge exchange efficiency at the solid-liquid interface from both interfacial resistance and mass transfer kinetics perspectives.

[0107] Test Example 5: Comprehensive comparison of specific capacitance and rate performance.

[0108] This test aims to systematically evaluate the constant current charge-discharge performance of electrodes prepared by different methods under different current densities, so as to comprehensively consider their specific capacitance and rate performance. The test objects are the electrode samples of Example 1, Comparative Example 1, Comparative Example 3 and Comparative Example 4.

[0109] The same three-electrode testing system as in Test Example 3 was used, with 0.5 mol / L sodium sulfate aqueous solution as the electrolyte. The self-supporting electrode samples from Example 1, Comparative Example 3, and Comparative Example 4 were cut into 1 cm × 1 cm sizes to serve as working electrodes; the nickel foam loaded with active material in Comparative Example 1 was directly used as the working electrode.

[0110] Connect the system to the electrochemical workstation and run the constant current charge-discharge (GCD) test program. Set the test voltage window to 0V to 0.8V.

[0111] The working electrode's specific current density was sequentially set to 0.5 A / g, 1 A / g, 2 A / g, 5 A / g, and 10 A / g, and the charge-discharge curves at each current density were recorded. Based on the discharge curves, the formula was used... The specific capacitance was calculated. This is the discharge current. Discharge time, For the quality of active substances, This represents the discharge voltage window.

[0112] The ratio of the specific capacitance at a current density of 10 A / g to that at a current density of 0.5 A / g is calculated to obtain the capacitance retention rate at high rates.

[0113] Table 5. Specific capacitance and rate performance of the examples and comparative examples Reference Appendix Figure 5 , Figure 5 The horizontal axis represents the current density (A / g) set in the constant current charge-discharge test, and the vertical axis represents the calculated specific capacitance (F / g). Different line types and marked curves in the figure correspond to different samples: solid lines and solid squares represent Example 1, dashed lines and hollow circles represent Comparative Example 1, dotted lines and gray triangles represent Comparative Example 3, and dotted lines and hollow rhombuses represent Comparative Example 4.

[0114] In summary, based on the data in Table 5, the electrode's capacity at low current densities reflects its static charge storage capability, which is directly related to the material's effective electrochemical specific surface area. Example 1 achieved a specific capacitance of 181.5 F / g at 0.5 A / g; its hierarchical porous network structure and the additional interface provided by the conductive polymer offered ample wetting and contact sites for electrolyte ions. In contrast, Comparative Example 4, due to structural densification caused by conventional drying methods, had an initial specific capacitance of only 95.3 F / g, indicating that a large number of potential active surfaces were physically shielded and unusable. The introduction of the inert binder in Comparative Example 1 and the potential stacking of rGO sheets in Comparative Example 3 also contributed to the reduction in initial specific capacitance compared to Example 1.

[0115] The performance of the electrode at high rates reflects the efficiency of ion and electron transport within the material. When the current density increases from 0.5 A / g to 10 A / g, the capacitance retention of Example 1 reaches 65.3%, demonstrating its adaptability to rapid charge transfer. This performance is attributed to the structure constructed by the present invention: the large-sized channels formed by rapid laser pore drilling constitute the main channel for rapid ion transport; while the three-dimensional network supported by the PEDOT:PSS molecular chains ensures the effective shortening of the ion diffusion path within the micro-region. Simultaneously, the conductive network running throughout ensures that electrons can be collected or injected in a timely manner, achieving a match between electron and ion dynamics. The rate performance of the comparative electrodes is limited by their respective structures. The capacitance retention of Comparative Example 1 is only 24.9%, and the dense coating and binder make the ion transport path within the electrode tortuous, increasing mass transfer resistance under high-frequency charge and discharge. The rapid capacity decay observed in Comparative Examples 3 (31.4%) and 4 (8.2%) both point to the lack of effective channel support. Ions struggle to penetrate the stacked rGO sheets or dense material bulk within a short time, leading to the failure of numerous deep active sites at high magnification. In summary, the test data confirm that the strategy of constructing a self-supporting, multi-level porous, two-component conductive network through laser direct writing in this invention synergistically optimizes the charge storage capacity and kinetic transport characteristics of the electrode.

[0116] Test Example 6: Comparison of the adsorption performance of capacitive deionization (CDI) on perfluorooctanoic acid.

[0117] This test aims to evaluate the adsorption performance of electrode materials for perfluorooctanoic acid (PFOA) in capacitive deionization mode, in order to verify the application of this invention in the field of novel pollutant treatment. The electrode samples from Example 1 and Comparative Example 3 were selected as test subjects, and commercial activated carbon (referred to as Comparative Example 5) was introduced as a reference standard.

[0118] The self-supporting electrodes of Example 1 and Comparative Example 3 were cut into two 4cm×5cm electrode sheets; commercial activated carbon powder, polyvinylidene fluoride binder, and carbon black were mixed in a mass ratio of 8:1:1, coated onto a foam titanium current collector, dried, and then cut into electrode sheets of the same size (Comparative Example 5).

[0119] Assemble the flow-through CDI module by placing two identical electrode plates as the anode and cathode in parallel, with a 300μm thick nylon mesh in between as a diaphragm and flow channel.

[0120] Prepare aqueous solutions of perfluorooctanoic acid with different initial concentrations (5, 10, 20, 40, 60 mg / L) and add 50 mg / L sodium chloride as a background electrolyte to maintain the basic conductivity of the solution.

[0121] Connect the CDI module to the peristaltic pump and DC power supply. At each concentration point, pump the target solution into the CDI module at a flow rate of 15 mL / min for 30 minutes to allow the electrode and solution to reach physical adsorption equilibrium.

[0122] A constant voltage of 1.2V was applied across the electrodes for electroadsorption, with the anode connected to the positive electrode and the cathode to the negative electrode. The adsorption process lasted for 120 minutes, with samples taken every 30 minutes.

[0123] The equilibrium concentration (Ce) in the solution was determined using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS). The formula was used to determine the equilibrium concentration (Ce) in the solution. Calculate the equilibrium adsorption capacity of the electrode ( ), where C0 is the initial concentration, This is the total volume of the solution. This represents the total mass of active material on both electrodes.

[0124] Table 6. Equilibrium adsorption isotherm data of PFOA in the examples and comparative examples Reference Appendix Figure 6 , Figure 6 The horizontal axis represents the remaining concentration of PFOA (Ce) in the solution after adsorption equilibrium, and the vertical axis represents the equilibrium adsorption capacity per unit mass of the electrode material. Solid lines and solid squares depict the adsorption behavior of Example 1, dotted lines and gray triangles represent Comparative Example 3 (pure rGO electrode), and dashed lines and hollow circles represent Comparative Example 5 (commercial activated carbon electrode).

[0125] In summary, based on the data in Table 6, the equilibrium adsorption capacity of the electrode in Example 1 for PFOA at different initial concentrations exceeded that of Comparative Examples 3 and 5, indicating that the electrode material has adsorption advantages in capacitive deionization applications.

[0126] This difference in adsorption performance can be explained by the interaction between the electrode's microstructure and the CDI working mechanism. Under an applied electric field, negatively charged PFOA anions migrate towards the anode and are electrostatically captured. The electrode in Example 1, constructed using laser direct writing technology, features a three-dimensional hierarchical pore network. This network provides ample adsorption sites for PFOA molecules, and the interconnected pore structure reduces mass transfer resistance, facilitating the diffusion of contaminant molecules into the material.

[0127] Besides the macroscopic pore structure, the synergistic effect between material components also contributes to the adsorption performance. There is a physical affinity between the graphitized surface of rGO and the hydrophobic fluorinated long chains of PFOA molecules. Furthermore, the introduction of PEDOT:PSS, in addition to constructing an electronic conduction network to maintain the electrode potential, physically hinders the recombination of rGO sheets, maintaining the openness and accessibility of the pores. This structural advantage is even more evident in comparisons with comparative examples.

[0128] The pure rGO electrode in Comparative Example 3 lacks polymer support, making the sheets prone to aggregation and resulting in the shielding of some effective surface areas. As a control, the commercial activated carbon (Comparative Example 5) has a predominantly microporous pore size distribution, which creates steric hindrance for larger organic molecules like PFOA, restricting their entry into the pores. Therefore, its equilibrium adsorption capacity is also lower than that in Example 1.

[0129] In summary, the electrode of Example 1 combines electrostatic adsorption with physical affinity by integrating a continuous electron conduction network, a highly accessible specific surface area, and a hierarchical pore structure. The test results verify the feasibility of the present invention in treating persistent fluorinated organic pollutants.

[0130] Application Example 1: It is used as a capacitive deionization (CDI) electrode for the removal of perfluorooctanoic acid (PFOA) from water. This application example demonstrates the use of the electrode prepared according to the present invention in capacitive deionization technology to efficiently remove persistent organic pollutant perfluorooctanoic acid (PFOA) from water.

[0131] Electrode preparation: First, following the method described in Example 1, a self-supporting PEDOT / rGO porous electrode was prepared in a PEDOT / rGO composite precursor solution using laser direct writing technology. This electrode exhibits a three-dimensional porous network structure, excellent conductivity, and mechanical integrity.

[0132] CDI device assembly: The self-supporting electrode obtained in step 1 is cut into two 4cm×5cm electrode sheets, which serve as the anode and cathode. The two electrodes are placed parallel to each other, with a 300μm thick nylon mesh in between as a diaphragm and flow channel, and assembled into a flow-through CDI module.

[0133] Adsorption operation procedure: Solution preparation: Prepare an aqueous solution of perfluorooctanoic acid (PFOA) with an initial concentration of 40 mg / L, and add 50 mg / L sodium chloride as a background electrolyte to maintain the basic conductivity of the solution.

[0134] Electroadsorption process: The above PFOA solution was pumped into the CDI module at a flow rate of 15 mL / min for circulation. A constant DC voltage of 1.2 V was applied across the electrodes (anode to positive electrode, cathode to negative electrode) for electroadsorption treatment for 120 minutes.

[0135] Performance evaluation: The equilibrium concentration of PFOA in the treated solution was determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS), and the equilibrium adsorption capacity of the electrode was calculated. ).

[0136] Application effect: The results showed that the electrode prepared using Example 1 of the present invention exhibited an excellent equilibrium adsorption capacity of 321.7 mg / g for PFOA. This value is superior to that of a pure rGO electrode prepared using the same laser process (Comparative Example 3, adsorption capacity of 247.2 mg / g) and a commercial activated carbon electrode (Comparative Example 5, adsorption capacity of 168.1 mg / g), which serves as the industry benchmark.

[0137] In summary, this application example demonstrates that the self-supporting PEDOT / rGO composite electrode prepared by this invention, with its unique three-dimensional hierarchical pore network, the synergistic effect of the two components (the hydrophobic affinity of rGO and the spatial support and conductivity of PEDOT:PSS), and its highly accessible specific surface area, can serve as a highly efficient CDI electrode in the field of water treatment, particularly for the removal of persistent fluoride-containing organic pollutants, and has technical advantages and broad application prospects.

[0138] Application Example 2: As an electrode for high-performance supercapacitors This application example demonstrates the use of the electrode prepared according to the present invention as a core energy storage material in a high-performance supercapacitor.

[0139] Electrode fabrication: Similarly, a self-supporting PEDOT / rGO composite electrode was fabricated according to the method described in Example 1.

[0140] Electrochemical testing system assembly: The prepared electrodes are cut into 1cm×1cm sizes and used directly as working electrodes without any binders or conductive additives.

[0141] A standard three-electrode testing system was constructed, in which a platinum wire was used as the counter electrode, a saturated calomel electrode was used as the reference electrode, and a 0.5 mol / L sodium sulfate (Na2SO4) aqueous solution was used as the electrolyte.

[0142] Performance testing process: The assembled three-electrode system was connected to an electrochemical workstation, and its performance as a supercapacitor electrode was systematically evaluated within a potential window of 0V to 0.8V using methods such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS).

[0143] High specific capacitance: At a current density of 0.5 A / g, the electrode exhibits a high specific capacitance of 181.5 F / g, demonstrating its excellent charge storage capability.

[0144] Excellent rate performance: When the current density is increased 20 times from 0.5 A / g to 10 A / g, the capacitance retention rate is still as high as 65.3%. This indicates that the ion and electron transport channels inside the electrode are highly efficient and can adapt to fast charge and discharge applications.

[0145] Low internal resistance: Electrochemical impedance spectroscopy analysis shows that the equivalent series resistance (Rs) of the electrode is only 1.27Ω, and the charge transfer resistance (Rct) is as low as 0.83Ω. Lower internal resistance means less energy loss and higher power output.

[0146] Performance comparison: Its overall performance far exceeds that of electrodes prepared by traditional coating processes (Comparative Example 1, rate performance of only 24.9%, high internal resistance) and pure rGO electrodes with easy stacking structure (Comparative Example 3, rate performance of 31.4%, relatively high internal resistance).

[0147] In summary, this application example demonstrates that the self-supporting, multi-level porous, two-component conductive network structure constructed by laser direct writing successfully optimizes the charge storage capacity and kinetic transport characteristics of the electrode. This electrode eliminates the need for current collectors and binders, simplifying the device structure and reducing internal resistance, thus demonstrating its significant application potential in high-power, high-efficiency energy storage devices such as supercapacitors and hybrid capacitors.

Claims

1. A laser fabrication method for a self-supporting PEDOT / rGO porous electrode, characterized in that, Includes the following steps: A partially reduced graphene oxide aqueous dispersion was mixed with a PEDOT:PSS aqueous dispersion to obtain a PEDOT / rGO composite precursor solution. The PEDOT / rGO composite precursor liquid was processed using a laser direct writing system, and in-situ reduction and cross-linking were induced by photothermal action to form a three-dimensional structure material. Clean the three-dimensional structural material to remove unreacted precursors; The cleaned three-dimensional structural material is freeze-dried to obtain the self-supporting PEDOT / rGO porous electrode.

2. The laser fabrication method according to claim 1, characterized in that, In the step of mixing partially reduced graphene oxide aqueous dispersion with PEDOT:PSS aqueous dispersion to obtain PEDOT / rGO composite precursor solution, the volume ratio of PEDOT / rGO composite precursor solution is (1-2):

1.

3. The laser fabrication method according to claim 1, characterized in that, The step of obtaining the PEDOT / rGO composite precursor liquid also includes ultrasonic treatment of the mixed liquid for 30-60 minutes.

4. The laser fabrication method according to claim 1, characterized in that, The partially reduced graphene oxide aqueous dispersion was prepared by the following method: A hydrothermal reaction was carried out on an aqueous dispersion of graphene oxide with a concentration of 1-5 mg / mL at a temperature of 40-80℃ for 5-12 hours.

5. The laser fabrication method according to claim 4, characterized in that, The specific conditions for the hydrothermal reaction are as follows: A 2 mg / mL aqueous dispersion of graphene oxide was used and reacted at 60 °C for 8 hours.

6. The laser fabrication method according to claim 1, characterized in that, In the step of processing using the laser direct writing system, the laser parameters used are as follows: The wavelength is 450-532nm and the power is 1.35-5W.

7. The laser fabrication method according to claim 1, characterized in that, The processing steps using the laser direct writing system are performed in an inert gas atmosphere.

8. A self-supporting PEDOT / rGO porous electrode, characterized in that, It is composed of partially reduced graphene oxide and PEDOT:PSS composite; It features a three-dimensional porous structure and an integrated structure without binders.

9. The application of self-supporting PEDOT / rGO porous electrodes, characterized in that, The self-supporting PEDOT / rGO porous electrode described in claim 8 is used to prepare an energy storage device.

10. The application according to claim 9, characterized in that, The energy storage device is a capacitor deionization device or a supercapacitor.

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