A pedot:pss conductive gel, a high-performance thermoelectric gel prepared therefrom, and a preparation method thereof

Abstract

The application belongs to the technical field of thermoelectric material preparation, and particularly relates to a PEDOT:PSS conductive gel, a high-performance thermoelectric gel prepared therefrom and a preparation method thereof. In the application, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is selected as an electron transport matrix, a PEDOT:PSS conductive gel skeleton is constructed through induced phase separation and thermal field excitation self-assembly, ultra-high electron migration is realized, the conductivity is improved, and the mechanical performance and photothermal performance are simultaneously improved. Meanwhile, a redox pair / ion salt is further introduced to construct an oxidation-reduction potential and an ionic thermal diffusion potential, a huge ionic entropy can construct an ultra-high thermoelectric voltage, and ion transmission characteristics are exhibited. The continuous conductive skeleton in the thermoelectric gel prepared in this way can ensure efficient transmission of electrons, and the mutual migration and action of ions realize a huge ionic thermoelectric voltage. Through ion-electron synergistic effect, the decoupling between the ionic thermoelectric voltage and the electrical performance is realized, and the thermoelectric performance is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of thermoelectric material preparation technology, specifically relating to a PEDOT:PSS conductive gel, a high-performance thermoelectric gel prepared therefrom, and a preparation method thereof. Background Technology

[0002] From basic generators to data centers and even the human body, a significant amount of waste heat is generated. Specifically, more than half of primary energy is released into the environment as heat. Of this, 63% is low-grade heat energy with temperatures below 100°C, which is difficult to collect and utilize, resulting in substantial waste. Research indicates that thermoelectric materials capable of capturing dispersed heat sources show great potential for low-grade heat energy harvesting.

[0003] Thermoelectric materials are classified into conventional thermoelectric (e-TE) materials, which rely primarily on electron transport, and ionic thermoelectric (i-TE) materials, which rely primarily on ion transport. However, the electron enthalpy of e-TE materials is too low, resulting in an extremely low Seebeck coefficient (S), only reaching the microvolt level (10⁻¹⁰). 1 -10 2 μV K -1 Although the Seebeck coefficient and conductivity of materials can be tuned through doping and hybridization, the optimized thermoelectric performance is still limited, hindering its practical application in the low-grade region (<100℃). Furthermore, in terms of device design for practical power generation, a working voltage of 1.5V typically requires the assembly of more than 100 electronic thermoelectric materials, which is detrimental to the trend of miniaturization. In contrast, ionic thermoelectric materials, due to their large ion entropy, exhibit significant advantages in low-grade power generation due to their flexibility and high voltage characteristics. Based on the mechanism, they can be divided into potential differences caused by ion thermal diffusion under temperature gradients (Thermodiffusion Effect) and potential differences caused by the gain and loss of electrons during redox reactions between ions (Thermogalvanic Effect). The large ion entropy endows the material with an order-of-magnitude increase in thermal voltage (10⁻¹⁰). 3 -10 4 μVK -1 However, the extremely low mobility of ions causes a sharp decline in their electrical properties, limiting their thermoelectric conversion efficiency. Furthermore, ion thermal diffusion only allows them to accumulate on the electrode surface, preventing continuous power generation; the voltage decays over time, making direct application difficult. Therefore, given the inherent limitations of both e-TE and i-TE materials, a new mechanism is urgently needed to improve their conversion efficiency.

[0004] Since the thermoelectric properties of e-TE are mainly influenced by carrier concentration and mobility, its extremely high carrier concentration and mobility give it excellent conductivity, but also result in a less than ideal Seebeck coefficient. i-TE, due to its extremely low ion migration velocity and large Eastman entropy, exhibits an extremely high Seebeck coefficient, but its conductivity is extremely low. Given the complementary nature of e-TE and i-TE, combining the characteristics of electron and ion transport—utilizing electron transport to achieve ultra-high conductivity while simultaneously constructing ion thermal voltage using ion transport—and designing a new transport mechanism holds promise for decoupling the Seebeck coefficient and electrical properties, leading to a breakthrough in thermoelectric performance. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), due to its extremely high electrical properties, good flexibility, and solution processing performance, is one of the promising materials for achieving electron transport and ion conversion. However, electron transport and ion conversion require a gel state. In PEDOT:PSS, the hydrophilic insulating PSS chains make the gel unstable in water, hindering direct gel formation. Therefore, obtaining a stable, highly conductive PEDOT:PSS electronic framework and stable ion transport to construct ionothermal voltages is a potential strategy to significantly improve the conductivity and Seebeck coefficient of thermoelectric materials. However, few studies have investigated the synergistic effect of electron-ion interaction on the Seebeck coefficient, electrical properties, and thermoelectric properties of these materials. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a promising solution: selecting poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as the electron transport matrix. This is due to PEDOT's extremely high electrical properties, good flexibility, and solution processing performance, making it a promising material for electron transport and ion conversion. A complete conductive network is constructed by designing the PEDOT:PSS gel framework, achieving ultra-high conductivity. Simultaneously, redox pairs / ionic salts are introduced within the gel to construct redox potentials and ion thermal diffusion potentials. The enormous ion entropy can generate ultra-high thermal voltages, exhibiting ion transport characteristics. The continuous conductive framework ensures efficient electron transport, while the mutual migration and interaction of ions achieve excellent ion thermal voltages. Therefore, the synergistic effect of ions and electrons is expected to decouple the Seebeck coefficient from electrical properties, thereby significantly optimizing the thermoelectric conversion efficiency of the material.

[0006] Specifically, the present invention provides a method for preparing a PEDOT:PSS conductive gel with enhanced mechanical and photothermal properties, comprising introducing small molecules capable of enhancing the electrostatic shielding effect of PEDOT:PSS into an aqueous solution of PEDOT:PSS to induce internal phase separation of PEDOT:PSS, obtaining a PEDOT:PSS gel solution, and then performing heat treatment to stimulate the self-assembly of conjugated π bonds on the PEDOT molecular chain to obtain the PEDOT:PSS conductive gel with enhanced mechanical and photothermal properties.

[0007] As used in this paper, the PEDOT:PSS aqueous solution is commercially available with a solid content of 1.25 wt%, wherein the PEDOT:PSS ratio is 1:2.5 (wt).

[0008] Furthermore, the small molecule can induce phase separation in the PEDOT:PSS solution, including, for example, ion-induced phase separation, polar solvent-induced phase separation, or proton-acid exchange-induced phase separation.

[0009] Furthermore, the small molecule is selected from ionic liquids, polar solvents, or protic acids.

[0010] Further, the ionic liquid is selected from at least one of 1-ethyl-3-methylimidazolium dicyandiamide (EMIM:DCA), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM:BF4) or other hydrophilic ionic liquids, or 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIM:TFSI) or other hydrophobic ionic liquids.

[0011] Furthermore, the protic acid is selected from at least one of sulfuric acid, hydrochloric acid, and acetic acid.

[0012] Furthermore, the polar solvent is selected from at least one of methanol, ethylene glycol, and dimethyl sulfoxide.

[0013] Furthermore, the mass percentage concentration of the small molecule in the PEDOT:PSS / ionic liquid mixed solution is 1-30 wt%, preferably 5-10 wt%.

[0014] Furthermore, the preparation method includes thoroughly stirring and mixing PEDOT:PSS with small molecules that can enhance the electrostatic shielding effect of PEDOT:PSS, followed by ultrasonic treatment to promote dispersion, thereby achieving induced phase separation.

[0015] Furthermore, PEDOT:PSS was mixed with small molecules that could enhance the electrostatic shielding effect of PEDOT:PSS at room temperature for 10-30 min, and then sonicated in a homogenizer for 10-30 min to ensure uniform mixing and remove air bubbles, resulting in a PEDOT:PSS gel solution.

[0016] Furthermore, the heat treatment includes a sealed treatment at 50-90°C for 10-180 minutes.

[0017] Preferably, the heat treatment includes a sealed treatment at 70-90°C for 120-180 minutes.

[0018] Furthermore, the PEDOT:PSS gel solution is sealed with a sealing film to prevent moisture loss.

[0019] Furthermore, the preparation method also includes washing the obtained PEDOT:PSS conductive gel to remove residual ionic liquid.

[0020] Furthermore, the washing process includes immersing the obtained PEDOT:PSS conductive gel in distilled water once or multiple times, each time for 60-120 minutes.

[0021] The present invention also provides a PEDOT:PSS conductive gel with enhanced mechanical and photothermal properties prepared by the method described herein.

[0022] This invention also provides a method for preparing a high-performance thermoelectric gel with synergistic electron-ion interaction, which includes further introducing redox pairs and ionic salts into the PEDOT:PSS conductive gel prepared herein, thereby constructing redox potential and ionic thermal diffusion potential inside the gel.

[0023] Furthermore, the redox pair includes Fe 3+ / Fe 2+ Redox pairs, I - / I 3- At least one of a redox pair or other redox pairs.

[0024] Furthermore, the Fe 3+ / Fe 2+ Redox pairs are ferric salt / ferrous salt redox pairs, including ferric cyanate / ferrous cyanate redox pairs and ferric chloride / ferrous chloride redox pairs.

[0025] Furthermore, the Fe 3+ / Fe 2+ Redox pairs include the potassium ferricyanide / potassium ferrocyanide redox pair.

[0026] Furthermore, the ionic salt is at least one of sodium chloride (NaCl), potassium chloride (KCl), and sodium bromide (NaBr).

[0027] Furthermore, the method of introducing redox pairs and ionic salts into PEDOT:PSS conductive gel includes immersing the PEDOT:PSS conductive gel in a mixed solution of redox pairs and ionic salts, and then heating it to fully achieve ion diffusion, thereby obtaining a thermoelectric gel with electron-ion synergistic effect.

[0028] Furthermore, in the mixed solution of the redox pair and the ionic salt, the molar concentration of the redox pair is 0.05 mol / L-3 mol / L, and the molar concentration of the salt is 0.1-1 mol / L.

[0029] Furthermore, the mixed solution of the redox pair and the ionic salt can be prepared as follows: the redox pair is dissolved in distilled water, ultrasonically treated to promote dissolution and dispersion, and then the ionic salt is added and stirred to obtain the mixed solution of redox pair / ionic salt.

[0030] Furthermore, the ionic salt is dissolved by stirring at 200-500 rpm and 30-50°C for 20-30 minutes.

[0031] Furthermore, the heat treatment includes treatment at 70-90°C for 60-180 minutes.

[0032] This invention also provides a high-performance thermoelectric gel with electron-ion synergy prepared by the methods described herein.

[0033] Beneficial effects of the present invention

[0034] 1. This invention constructs a PEDOT:PSS conductive gel framework through induced phase separation and thermally excited self-assembly, significantly increasing the carrier concentration and optimizing the arrangement of conductive PEDOT domains. This results in the gel framework exhibiting excellent electrical, mechanical, and photothermal properties. The enhanced conductivity of the PEDOT:PSS gel can be attributed to two factors: the interconnection of PEDOT conductive domains and the conformational transformation of PEDOT. When an ionic liquid is introduced, the electrostatic interactions between small molecules help weaken the electrostatic attraction between PEDOT and PSS, thereby promoting the extension and alignment of PEDOT molecular chains. This process enables the conformational transformation of PEDOT from a coiled benzene structure to a straight-chain quinone structure, contributing to the increase in carrier concentration and promoting the alignment and crystallization of PEDOT molecular chains, thus enhancing electrical properties.

[0035] 2. This invention further introduces redox pairs and ionic salts into the prepared PEDOT:PSS conductive gel framework, thereby constructing redox potentials and ionic thermal diffusion potentials within the gel. The synergistic effect of these redox potentials and ionic thermal diffusion potentials provides a significant ionic thermal voltage. The resulting thermoelectric gel achieves high conductivity, excellent thermal voltage, and thermoelectric power generation performance simultaneously. It has great application potential in human health monitoring, self-powered energy supply, and building and smart home applications.

[0036] 3. This invention combines electron transport with ion transport. This strategy not only holds promise for decoupling the Seebeck coefficient from electrical properties, potentially leading to a breakthrough in the conversion efficiency of future thermoelectric materials, but also provides crucial guidance for the design and application of thermoelectric materials by exploring the mechanism of internal electron-ion interactions. The EMIM:TFSI ionic liquid used is a green solvent with advantages of easy dissolution and removal, and is easier to handle compared to traditional solvents such as strong acids, strong bases, and other organic solvents. Attached Figure Description

[0037] Figure 1 The morphological changes of PEDOT:PSS before (a) and after (b) ion-induced phase separation and thermal field treatment in Example 1 of the present invention are shown.

[0038] Figure 2 The internal morphology of the PEDOT:PSS gel of Example 1 of the present invention is shown.

[0039] Figure 3 The conductivity of the PEDOT:PSS gel skeleton obtained in step 1 of Examples 1-3 and Comparative Example 1 is shown.

[0040] Figure 4 The mechanical properties of the PEDOT:PSS gel skeleton obtained in step 1 of Examples 1-3 and Comparative Example 1 are shown.

[0041] Figure 5 The photothermal properties of the PEDOT:PSS gel skeleton of Example 1 of the present invention are shown.

[0042] Figure 6 Seebeck coefficients for different solution immersion treatments in Example 1 and the comparative example of the present invention are shown.

[0043] Figure 7 The conductivity of different solution immersion treatments in Example 1 and the comparative example of the present invention is shown.

[0044] Figure 8 The power factors of different solution immersion treatments in Example 1 and the comparative example of the present invention are shown.

[0045] Figure 9 The power factors of different ionic liquid concentrations in Examples 1-3 and the comparative examples of the present invention are shown.

[0046] Figure 10 The Seebeck coefficients of thermogels prepared with different redox pair concentrations are shown.

[0047] Figure 11 The Seebeck coefficients of thermogels prepared with different NaBr salt concentrations are shown. Detailed Implementation

[0048] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0049] Example 1

[0050] (1) Preparation of PEDOT:PSS conductive gel: 1g of PEDOT:PSS aqueous solution (solid content 1.25wt%, of which PEDOT:PSS ratio is 1:2.5) was mixed with 10wt% hydrophobic ionic liquid EMIM:TFSI for 10-30 min, and then homogenized for 10 min to ensure uniform mixing and remove air bubbles, resulting in a PEDOT:PSS gel solution. The obtained mixed solution was placed in a mold, the opening was sealed with sealing film, and the mold was subjected to a heat field treatment at 90℃ for 120 min to promote π-π self-assembly, resulting in a uniform PEDOT:PSS gel. The obtained PEDOT:PSS gel was immersed in distilled water for 120 min to wash away residual PSS molecules and ionic liquid, and this process was repeated 3 times.

[0051] (2) Preparation of redox pair / salt solution: 0.9877 g K3[Fe(CN)6] and 1.2672 g K4[Fe(CN)6] were dissolved in 10 ml of distilled water and ultrasonically dispersed for 30 min. 1.0281 g NaBr was added to the solution and stirred at 200 rpm for 30 min to obtain a mixed solution of redox pair / salt.

[0052] (3) Preparation of electron-ion synergistic thermoelectric gel: Take out the PEDOT:PSS gel after washing with distilled water, place it in a mixed solution of redox pair (0.3 mol / L) / salt (1 mol / L), seal the opening with sealing film, place it in an oven at 90℃ for heat treatment for 180 min, take it out and cool it to room temperature to obtain electron-ion synergistic thermoelectric gel (represented by PIL / Fe / NaBr).

[0053] In this embodiment, step (1) yields a PEDOT:PSS gel. Due to the tight connection of the PEDOT backbone, it exhibits excellent conductivity, mechanical properties, and photothermal properties. Figure 3-5 Meanwhile, the thermoelectric gel obtained in step (3) has good scaffold strength and connectivity, and Fe(CN)6 is successfully introduced into the gel interior. 3- / Fe(CN)6 4- Na + and Br - This demonstrates excellent electrical properties and a good ion Seebeck voltage, ultimately achieving a simultaneous improvement in thermoelectric performance. Figure 6-9 ).

[0054] Example 2

[0055] Following the method of Example 1, a PEDOT:PSS gel solution was first prepared. The resulting mixed solution was placed in a mold, the opening was sealed with a sealing film, and the solution was subjected to a heat field treatment at 90°C for 120 min to promote π-π self-assembly, resulting in a uniform PEDOT:PSS gel. The obtained PEDOT:PSS gel was then immersed in distilled water for 120 min to wash away residual PSS molecules and ionic liquid, repeated three times. The PEDOT:PSS gel after distilled water washing was removed and placed in a redox pair / salt mixed solution. The opening was sealed with a sealing film, and the solution was subjected to a heat field treatment in an oven at 90°C for 180 min. After removal and cooling to room temperature, an electron-ion mixed thermoelectric gel was obtained. The remaining parameter selection and preparation process were the same as in Example 1, except that the mass percentage concentration of the ionic liquid used in Example 1 was adjusted to 1 wt%.

[0056] Compared to Example 1, this example has a lower ionic liquid content in the early phase separation treatment of PEDOT:PSS. Therefore, the gel skeleton obtained in step 1 of this example has poorer connectivity and strength compared to Example 1, and its electrical, mechanical, and photothermal properties are significantly reduced. Figure 3-4 After step (3), the final thermoelectric properties of the obtained thermoelectric gel also decreased, but were still better than those of the control sample. Figure 9 ).

[0057] Example 3

[0058] Following the method of Example 1, a PEDOT:PSS gel solution was first prepared. The resulting mixed solution was placed in a mold, the opening was sealed with a sealing film, and the solution was subjected to a heat field treatment at 90°C for 120 min to promote π-π self-assembly, resulting in a uniform PEDOT:PSS gel. The obtained PEDOT:PSS gel was then immersed in distilled water for 120 min to wash away residual PSS molecules and ionic liquid, repeated three times. The PEDOT:PSS gel after distilled water washing was removed and placed in a redox pair / salt mixed solution. The opening was sealed with a sealing film, and the solution was subjected to a heat field treatment in an oven at 90°C for 180 min. After removal and cooling to room temperature, an electron-ion mixed thermoelectric gel was obtained. The remaining parameter selection and preparation process were the same as in Example 1, except that the mass percentage concentration of the ionic liquid used in Example 1 was adjusted to 30 wt%.

[0059] Compared to Example 1, this example has an excess of ionic liquid in the PEDOT:PSS gel obtained in step 1 during the initial phase separation process. Excessive ionic liquid can cause aggregation, hindering the connection of PEDOT domains and weakening its electrical and mechanical properties. However, it is still superior to pure PEDOT:PSS gel. Figure 3-4 Simultaneously, the disappearance of the internal porous structure prevents ionic salts and redox pairs from entering. Therefore, the gel skeleton obtained in this embodiment has a lower degree of connectivity and strength compared to Example 1, resulting in lower electrical properties, a significantly reduced ionic thermal voltage, and ultimately, poorer thermoelectric performance. However, due to the synergistic effect of ions and electrons, its thermoelectric performance is still superior to that of the control sample group. Figure 9 ).

[0060] Example 4

[0061] Following the method of Example 1, a PEDOT:PSS gel solution was first prepared. The resulting mixed solution was placed in a mold, the opening was sealed with a sealing film, and the solution was subjected to a thermal field treatment at 90°C for 120 min to promote π-π self-assembly, resulting in a uniform PEDOT:PSS gel. The obtained PEDOT:PSS gel was then immersed in distilled water for 120 min to wash away residual PSS molecules and ionic liquid, repeated three times. Subsequently, 0.0329 g of K3[Fe(CN)6] and 0.0423 g of K4[Fe(CN)6] were dissolved in 10 ml of distilled water and ultrasonically dispersed for 30 min. 1.0281 g of NaBr was added to the solution and stirred at 200 rpm for 30 min to obtain a redox pair / salt mixed solution. The PEDOT:PSS gel, after being washed with distilled water, was placed in the redox pair / salt mixed solution, the opening was sealed with a sealing film, and the solution was placed in a thermal field treatment at 90°C for 180 min. After removal and cooling to room temperature, an electron-ion mixed thermoelectric gel was obtained. The selection of other parameters and the preparation process are the same as in Example 1. The difference is that the concentration of the redox pair used in Example 1 is adjusted to 0.1 mol / L in this example.

[0062] Compared to the control sample, although the redox pair concentration was reduced, the synergistic effect of electrons and ions was successfully introduced into the sample, thus exhibiting a significant performance improvement. However, compared to Example 1, the ionic thermal voltage of the thermoelectric gel decreased due to the significantly reduced concentration of ions involved in the redox reaction, adversely affecting the thermoelectric performance. Figure 10 ).

[0063] Example 5

[0064] Following the method of Example 1, a PEDOT:PSS gel solution was first prepared. The resulting mixed solution was placed in a mold, the opening was sealed with a sealing film, and the solution was subjected to a thermal field treatment at 90°C for 120 min to promote π-π self-assembly, resulting in a uniform PEDOT:PSS gel. The obtained PEDOT:PSS gel was then immersed in distilled water for 120 min to wash away residual PSS molecules and ionic liquid, repeated three times. 0.9877 g of K3[Fe(CN)6] and 1.2672 g of K4[Fe(CN)6] were dissolved in 10 ml of distilled water and ultrasonically dispersed for 30 min. 0.1028 g of NaBr was added to the solution and stirred at 200 rpm for 30 min to obtain a redox pair / salt mixed solution. The PEDOT:PSS gel, after being washed with distilled water, was placed in the redox pair / salt mixed solution, the opening was sealed with a sealing film, and the solution was placed in a thermal field treatment at 90°C for 180 min. After removal and cooling to room temperature, an electron-ion mixed thermoelectric gel was obtained. The selection of other parameters and the preparation process are the same as in Example 1. The difference is that the concentration of NaBr salt used in Example 1 is adjusted to 0.1 mol / L in this example.

[0065] Compared to the control sample, although the salt concentration was reduced, the synergistic effect of electrons and ions was still successfully introduced into the sample, thus exhibiting a significant performance improvement. Compared to Example 1, the significantly reduced concentration of introduced ions led to a substantial decrease in the concentration of ions undergoing thermal diffusion within the gel, resulting in a decrease in the ionic thermal voltage of the thermoelectric gel and adversely affecting its thermoelectric performance. Figure 11 ).

[0066] Comparative Example 1

[0067] PEDOT:PSS aqueous solution is cast into a tetrafluoroethylene mold and dried in an oven to obtain a PEDOT:PSS film. The film is then immersed in distilled water for 30-180 minutes to absorb water and swell, yielding pure PEDOT:PSS gel (denoted by P).

[0068] Comparative Example 2

[0069] 1 g of PEDOT:PSS aqueous solution was mixed with 10 wt% hydrophobic ionic liquid EMIM:TFSI for 10-30 min, followed by homogenization for 10-30 min to ensure homogeneity and remove air bubbles, yielding a PEDOT:PSS gel solution. The resulting mixture was placed in a mold, the opening sealed with sealing film, and subjected to a heat field treatment at 90°C for 10-180 min to promote π-π self-assembly, resulting in a homogeneous PEDOT:PSS gel (denoted as PIL).

[0070] Comparative Example 3

[0071] Following the method in Example 1, a PEDOT:PSS gel solution was first prepared. The resulting mixed solution was placed in a mold, the opening was sealed with a sealing film, and the solution was subjected to a heat field treatment at 90°C for 10-180 min to promote π-π self-assembly, resulting in a homogeneous PEDOT:PSS gel. The obtained PEDOT:PSS gel was then immersed in distilled water for 60-120 min to wash away residual PSS molecules and ionic liquids, repeated three times. The PEDOT:PSS gel after distilled water washing was removed and placed in a redox pair mixed solution. The opening was sealed with a sealing film, and the solution was subjected to a heat field treatment in an oven at 50-90°C for 60-180 min. After removal and cooling to room temperature, a PEDOT:PSS / redox pair gel (denoted as PIL / Fe) was obtained.

[0072] Comparative Example 4

[0073] Following the method in Example 1, a PEDOT:PSS gel solution was first prepared. The resulting mixed solution was placed in a mold, the opening was sealed with a sealing film, and the solution was subjected to a heat field treatment at 90°C for 10-180 min to promote π-π self-assembly, resulting in a uniform PEDOT:PSS gel. The obtained PEDOT:PSS gel was then immersed in distilled water for 60-120 min to wash away residual PSS molecules and ionic liquids, repeated three times. The PEDOT:PSS gel after distilled water washing was removed, placed in a NaBr salt solution, the opening was sealed with a sealing film, and the solution was subjected to a heat field treatment in an oven at 50-90°C for 60-180 min. After removal and cooling to room temperature, a PEDOT:PSS / NaBr gel (denoted as PIL / NaBr) was obtained.

[0074] Test Results

[0075] Figure 1 The morphological changes of PEDOT:PSS before (a) and after (b) ion-induced phase separation and thermal field treatment in Example 1 of the present invention are shown. It can be seen that a gel state was formed after ion-induced phase separation and thermal field treatment.

[0076] Figure 2 The internal morphology of the PEDOT:PSS gel skeleton obtained in step 1 is shown, indicating that the PEDOT:PSS gel skeleton was successfully prepared.

[0077] The electrical properties of the PEDOT:PSS gel backbone obtained in step 1 were then characterized, such as... Figure 3 As shown, the excellent conductivity indicates the successful construction of the electron transport framework. Furthermore, due to the tight connection of the PEDOT framework, it also exhibits excellent mechanical and photothermal properties, as shown in the results. Figure 4 and Figure 5As shown. The Seebeck coefficient, electrical properties, and thermoelectric properties of the PIL / Fe / NaBr samples from Comparative Examples 1 to 4 and Example 1 were tested, and the results are as follows. Figure 6-8 As shown, PIL / Fe / NaBr exhibits the best Seebeck coefficient, fully demonstrating that the combined introduction of the redox pair and salt provides both redox potential and ion diffusion potential, contributing to the enhancement of ionic thermoelectric voltage. Simultaneously, PIL / Fe / NaBr also displays excellent electrical properties, indicating the superiority of the PEDOT:PSS conductive framework construction, introducing electron transport and ultimately exhibiting optimal thermoelectric performance, showcasing the superiority of electron-ion synergy. By comparing the Seebeck coefficients of thermoelectric gels treated with different redox pairs and salt concentrations, as shown... Figure 10 and 11 As shown, different concentrations of treatment have varying effects on the ionic Seebeck voltage. Although they affect the ionic Seebeck coefficient, the Seebeck voltage of the treated thermogel is still significantly better than that of the control sample. Furthermore, by comparing the performance of the thermogel treated with different concentrations of ionic liquid and the control sample, the results are as follows... Figure 9 As shown. Although it affects the electrical properties and ionic Seebeck coefficient of the gel, the synergistic effect of electrons and ions still significantly improves its thermoelectric properties, ultimately far exceeding the thermoelectric properties of the control sample. In conclusion, the above experiments demonstrate that the thermoelectric gel with ionic-electron synergistic effect of the embodiments possesses highly efficient thermoelectric, electrical, and thermoelectric properties.

[0078] It should be noted that while the preferred embodiments of the present invention are provided in this specification, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of the present invention; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of the present invention. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of the present invention. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a PEDOT:PSS conductive gel with enhanced mechanical and photothermal properties, characterized in that, The process involves introducing small molecules that enhance the electrostatic shielding effect of PEDOT:PSS into an aqueous solution of PEDOT:PSS to induce internal phase separation of PEDOT:PSS, resulting in a PEDOT:PSS gel solution. Then, heat treatment is performed to stimulate the self-assembly of conjugated π bonds on the PEDOT molecular chain, resulting in the PEDOT:PSS conductive gel with enhanced mechanical and photothermal properties. The small molecule that enhances the electrostatic shielding effect on PEDOT:PSS is a hydrophobic ionic liquid. The hydrophobic ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) (EMIM:TFSI). The mass percentage concentration of the small molecule in the PEDOT:PSS / ionic liquid mixed solution is 1-30 wt%. The heat treatment is a closed-loop heat treatment.

2. The preparation method according to claim 1, characterized in that, The solid content of the PEDOT:PSS aqueous solution is 1.25wt%, of which PEDOT:PSS ratio is 1:2.

5.

3. The preparation method according to claim 1, characterized in that, The mass percentage of the small molecule in the PEDOT:PSS / ionic liquid mixed solution is 5-10 wt%.

4. The preparation method according to claim 1, characterized in that, The preparation method includes thoroughly stirring and mixing PEDOT:PSS with small molecules that can enhance the electrostatic shielding effect of PEDOT:PSS, followed by ultrasonic treatment to promote dispersion, thereby achieving induced phase separation.

5. The preparation method according to claim 4, characterized in that, The preparation method includes mixing PEDOT:PSS with small molecules that can enhance the electrostatic shielding effect of PEDOT:PSS at room temperature for 10-30 min, and then sonicating the mixture in a homogenizer for 10-30 min to ensure uniform mixing and remove air bubbles, thereby obtaining a PEDOT:PSS gel solution.

6. The preparation method according to claim 1, characterized in that, The heat treatment includes a sealed treatment at 50-90°C for 10-180 min.

7. The preparation method according to claim 6, characterized in that, The heat treatment includes a sealed treatment at 70-90°C for 120-180 min.

8. The preparation method according to claim 1, characterized in that, The preparation method further includes washing the obtained PEDOT:PSS conductive gel to remove residual ionic liquid.

9. The preparation method according to claim 8, characterized in that, The washing process involves immersing the obtained PEDOT:PSS conductive gel in distilled water once or multiple times, each time for 60-120 minutes.

10. A PEDOT:PSS conductive gel with enhanced mechanical and photothermal properties, characterized in that, It is obtained by the preparation method according to any one of claims 1-9.

11. A method for preparing a high-performance thermoelectric gel with synergistic electron-ion interaction, characterized in that, This includes introducing redox pairs and ionic salts into the PEDOT:PSS conductive gel according to claim 10, thereby constructing redox potentials and ionic thermal diffusion potentials within the gel.

12. The preparation method according to claim 11, characterized in that, The redox pair includes Fe 3+ / Fe 2+ The redox pair, I - / I 3- The redox pair or at least one of the other redox pairs.

13. The preparation method according to claim 12, characterized in that, The Fe 3+ / Fe 2+ The redox pair is a ferric salt / ferrous salt redox pair, including ferricyanide / ferrocyanide redox pair, ferric chloride / ferrous chloride redox pair.

14. The preparation method according to claim 13, characterized in that, The Fe 3+ / Fe 2+ The redox pair includes potassium ferricyanide / potassium ferrocyanide redox pair.

15. The preparation method according to claim 11, characterized in that, The ionic salt is at least one of sodium chloride (NaCl), potassium chloride (KCl), and sodium bromide (NaBr).

16. The preparation method according to claim 11, characterized in that, A method for introducing redox pairs and ionic salts into PEDOT:PSS conductive gels involves immersing the PEDOT:PSS conductive gels in a mixed solution of redox pairs and ionic salts, followed by heat treatment to fully achieve ion diffusion, resulting in a thermoelectric gel with synergistic electron-ion effects.

17. The preparation method according to claim 16, characterized in that, The molar concentration of the redox pair in the mixed solution of the redox pair and the ionic salt is 0.05 mol / L-3 mol / L, and the molar concentration of the salt is 0.1-1 mol / L.

18. The preparation method according to claim 16, characterized in that, The heat treatment includes treatment at 70-90°C for 60-180 min.

19. A high-performance thermoelectric gel with synergistic electron-ion interaction, characterized in that, It is obtained by the preparation method according to any one of claims 11-18.

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