Graphene composite ionic pyroelectric hydrogel, preparation method and application thereof

Abstract

The application belongs to the technical field of thermoelectric materials, and particularly relates to a graphene composite ion thermoelectric gel, a preparation method and application thereof. The thermoelectric gel comprises a gelled organic matrix, graphene and an oxidation / reduction electric pair. The thermoelectric gel takes the organic matrix as a gelled matrix, and by adding the graphene and the oxidation / reduction electric pair, the flexibility, plasticity, heat resistance and thermoelectric chemical effect of the gel are improved, so as to obtain high high-temperature ion thermoelectric potential and output power density. Meanwhile, the graphene provides an island-bridge structure, accelerates ion diffusion and migration, enhances the thermal diffusion effect of the oxidation / reduction electric pair ions, improves the ion thermoelectric potential and output power density of the thermoelectric gel, and makes the thermoelectric gel have good thermoelectric conversion performance, so that high voltage and high output power density can be output by using low-grade waste heat. In addition, the preparation process of the application is simple, green and environment-friendly, raw materials are easy to obtain, and the cost is low, so that good economic benefits are obtained.

Description

Technical Field

[0001] This invention belongs to the field of thermoelectric materials technology, and specifically relates to a graphene composite ionic thermoelectric gel, its preparation method, and its application. Background Technology

[0002] With the rapid development of 5G communication, the Internet of Things (IoT) technology and applications are also gradually developing. Trillions of sensors and electronic devices will be deployed in the IoT, integrating into a vast IoT system. Through real-time data acquisition, data will be uploaded to IoT control terminals, enabling effective human-machine interaction. To enable sensors or electronic devices in extreme environments to operate independently without the constraints of batteries or power grids, capturing energy from the surrounding environment to achieve energy self-sufficiency is one of the effective approaches for future IoT applications. Thermoelectric conversion technology can directly convert heat energy into electrical energy, offering advantages such as simple structure, no noise pollution, and ease of miniaturization.

[0003] Unlike traditional semiconductor electronic thermoelectric materials, ionic thermoelectric gels have attracted widespread attention due to their advantages such as high ionic thermoelectric potential (mV / K on the order of mV / K, compared to μV / K for electronic thermoelectric materials), excellent flexibility and other mechanical properties, environmental friendliness, and low cost. These advantages make them uniquely advantageous for power generation from low-grade waste heat (<100℃). Currently, ionic thermoelectric gel systems possess ultra-high thermoelectric potentials (>40mV / K), but their output power density is relatively low, severely restricting their further market application. Therefore, improving the output power density of ionic thermoelectric gels is particularly important. Furthermore, the current operating temperature of ionic thermoelectric gels is basically room temperature or even below zero degrees Celsius, exhibiting low heat resistance, which affects parameters such as ion diffusion rate, activation energy, and conductivity, thus impacting thermoelectric conversion performance.

[0004] Therefore, there is an urgent need to provide a composite ionic thermoelectric gel that has good output power density, flexibility, and can withstand high temperatures and large temperature differences, thereby achieving good thermoelectric conversion performance. Moreover, the preparation process is simple, environmentally friendly, and low in cost. Summary of the Invention

[0005] This invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions. This invention provides a graphene composite ionic thermoelectric gel, which has good output power density, flexibility, and can withstand high temperatures and large temperature differences, thereby achieving good thermoelectric conversion performance. Furthermore, the preparation process is simple, environmentally friendly, and low-cost.

[0006] The inventive concept of this invention: The thermoelectric gel of this invention uses an organic matrix as the gelling matrix, and by adding graphene and redox couples, it is beneficial to improve the flexibility, plasticity, heat resistance, and thermoelectric effect of the gel, thereby obtaining high high-temperature ionic thermoelectric potential and output power density. Specifically, after the thermoelectric gel and electrodes constitute a thermoelectric conversion device, the redox couple utilizes the thermoelectric effect to undergo an oxidation reaction at the hot end of the thermoelectric conversion device, releasing electrons that accumulate on the hot end electrode. These electrons return to the cold end of the thermoelectric conversion device through the external circuit; at the cold end electrode, electrons are received, and a reduction reaction occurs; the oxidation and reduction products return to the counter electrode through diffusion. At the same time, graphene provides a "island-bridge structure" similar to that of the redox couple, which accelerates the diffusion and migration of ions, enhances the thermal diffusion effect of the redox couple ions, and improves the ionic thermoelectric potential and output power density of the thermoelectric conversion device.

[0007] Therefore, a first aspect of the present invention provides a graphene composite ionic thermoelectric gel.

[0008] Specifically, a graphene composite ionic thermoelectric gel includes a gelled organic matrix, graphene, and an oxidation / reduction couple.

[0009] Preferably, the composite ionic thermoelectric gel further includes a solvent, the content of the gelling organic matrix is ​​0.001-0.55 g / mL, the content of graphene is 0.001-0.11 g / mL, and in the oxidation / reduction couple, the content of the oxidation couple is 0.0002-0.65 mol / L and the content of the reduction couple is 0.0001-0.33 mol / L.

[0010] More preferably, the content of the gelled organic matrix is ​​0.001-0.5 g / mL; the content of the graphene is 0.001-0.1 g / mL; and in the oxidation / reduction couple, the content of the oxidation couple is 0.0002-0.6 mol / L and the content of the reduction couple is 0.0001-0.3 mol / L.

[0011] More preferably, the content of the gelled organic matrix is ​​0.01-0.5 g / mL; the content of the graphene is 0.01-0.08 g / mL; and in the oxidation / reduction couple, the content of the oxidation couple is 0.01-0.4 mol / L and the content of the reduction couple is 0.02-0.2 mol / L.

[0012] Preferably, the gelling organic matrix includes at least one of gelatin, polyvinyl alcohol, carrageenan, and starch.

[0013] Preferably, the graphene includes at least one of monolayer graphene, multilayer graphene, and graphene oxide.

[0014] Preferably, the oxidation / reduction couple includes at least one of potassium ferrocyanide / potassium ferrocyanide and sodium ferrocyanide / sodium ferrocyanide.

[0015] Specifically, after the thermoelectric gel and electrodes constitute a thermoelectric conversion device, the oxidation / reduction couple Fe(CN)6 4- and Fe(CN)6 3- Utilizing the thermoelectrochemical effect, an oxidation reaction Fe(CN)6 occurs at the hot end of the thermoelectric conversion device. 4- -e→Fe(CN)6 3- Electrons are released and accumulate on the hot-end electrode. These electrons then return to the cold end of the thermoelectric conversion device via the external circuit. At the cold-end electrode, electrons are received, and a reduction reaction, Fe(CN)6, occurs. 3- +e→Fe(CN)6 4- The oxidation and reduction products return to the counter electrode through diffusion. Simultaneously, graphene provides an "island-bridge" structure, accelerating ion diffusion and migration, enhancing the thermal diffusion effect of the redox couple ions, and improving the ionic thermoelectric potential and output power density of the thermoelectric gel. Preferably, the solvent includes at least one of water, methanol, and propanol.

[0016] Preferably, the operating temperature range of the thermoelectric gel is 20-150℃.

[0017] More preferably, the operating temperature range of the thermoelectric gel is 25-120℃.

[0018] More preferably, the operating temperature range of the thermoelectric gel is 30-80°C.

[0019] Specifically, most current research on ion thermoelectric gels is based on room temperature or even below zero degrees Celsius, which has low heat resistance. As a result, there are almost no research reports on high-temperature regions such as 40-60°C. However, high-temperature regions are conducive to improving parameters such as ion diffusion rate and electrical conductivity, which is beneficial to further improving thermoelectric conversion performance. Research on developing and expanding the performance of high-temperature regions has important research significance and economic value for the recovery and utilization of low-grade waste heat.

[0020] Preferably, the thermoelectric potential of the thermoelectric gel is 0-22mV / K.

[0021] More preferably, the thermoelectric potential of the thermoelectric gel is 0-20mV / K.

[0022] Preferably, the mass ratio of the gelled organic matrix to the solvent is 2.5-3.5:7-9.

[0023] More preferably, the mass ratio of the gelled organic matrix to the solvent is 2.7-3.3:7.5-8.5.

[0024] More preferably, the mass ratio of the gelled organic matrix to the solvent is 3:8.

[0025] A second aspect of the present invention provides a method for preparing the graphene composite ionic thermogel described in the first aspect of the present invention.

[0026] Specifically, the preparation method of the graphene composite ionic thermogel includes the following steps:

[0027] The various raw material components were mixed to prepare a graphene composite ionic thermogel.

[0028] Preferably, the preparation method of the graphene composite ionic thermoelectric gel includes the following steps:

[0029] (1) The gelled organic matrix, graphene and redox couple are added to a solvent to obtain a mixture;

[0030] (2) Stir the mixture obtained in step (1) to obtain graphene composite ionic thermogel.

[0031] Preferably, in step (2), the stirring is carried out at a certain temperature, which is 25-100℃; more preferably, the temperature is 25-98℃.

[0032] Preferably, in step (2), the stirring speed is 180-1100 rpm and the stirring time is 0.1-52 h.

[0033] More preferably, in step (2), the stirring speed is 200-1000 rpm and the stirring time is 0.1-48 h.

[0034] Preferably, the graphene composite ionic thermogel is obtained by cooling after stirring.

[0035] A third aspect of the present invention provides a thermoelectric conversion device.

[0036] Specifically, the thermoelectric conversion device includes electrodes and the graphene composite ionic thermoelectric gel described in the first aspect of the present invention.

[0037] Preferably, the electrode is selected from at least one of graphite paper, carbon paper, and carbon cloth.

[0038] Specifically, the graphene composite ionic thermoelectric gel is located between and in contact with the electrodes.

[0039] A fourth aspect of the present invention provides a method for preparing the thermoelectric conversion device described in the third aspect of the present invention.

[0040] Specifically, the method for preparing the thermoelectric conversion device includes the following steps:

[0041] A graphene composite ion thermoelectric gel was placed in a mold, and then electrodes were used to cover the upper and lower ends of the mold to obtain a thermoelectric conversion device.

[0042] Specifically, the thermoelectric conversion device has a "sandwich" structure.

[0043] A fifth aspect of the present invention provides a thermoelectric power generation device.

[0044] Specifically, the thermoelectric power generation device includes the thermoelectric conversion device described in the third aspect of the present invention.

[0045] Preferably, the thermoelectric conversion device in the thermoelectric power generation device is one or more.

[0046] Preferably, when there are multiple thermoelectric conversion devices, the thermoelectric conversion devices are connected in series.

[0047] Preferably, the thermoelectric conversion devices are connected in series via graphite paper.

[0048] Specifically, the series connection of the thermoelectric conversion devices is not limited to graphite paper; other conductive materials can also be used.

[0049] Specifically, the aforementioned thermoelectric generator can recover electrical energy.

[0050] Preferably, the thermoelectric generator can recover electrical energy to obtain a voltage of 0-1V.

[0051] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows:

[0052] (1) The thermoelectric gel of the present invention uses an organic matrix as the gelling matrix, and by adding graphene and redox couple, it is beneficial to improve the flexibility, plasticity, heat resistance and thermoelectric effect of the gel, so as to obtain high high temperature ionic thermoelectric potential and output power density. At the same time, graphene provides a "island-bridge structure" similar to accelerate the diffusion and migration of ions, enhance the thermal diffusion effect of redox couple ions, improve the ionic thermoelectric potential and output power density of the thermoelectric gel, and make it have good thermoelectric conversion performance.

[0053] (2) The present invention modifies the gelled organic matrix by means of graphene and redox couple, so that the thermoelectric gel can withstand high temperature and large temperature difference, which is conducive to the establishment of thermoelectricity.

[0054] (3) The present invention uses an organic matrix with good flexibility as a gelling matrix, so that the prepared thermoelectric gel is a flexible gel with excellent flexibility, which is suitable for preparing flexible ion gel thermoelectric conversion devices and flexible thermoelectric power generation devices.

[0055] (4) The thermoelectric gel of the present invention can be used to make thermoelectric power generation devices and can utilize low-grade waste heat to output high voltage and high output power density, which has great application prospects in the Internet of Things and flexible wearable fields.

[0056] (5) The preparation process of this invention is simple, easy to operate, green and environmentally friendly, and the raw materials are easy to obtain, the cost is low, and it is easy to produce and apply on a large scale, which has good economic benefits. Attached Figure Description

[0057] Figure 1 This is a schematic diagram illustrating the working mechanism of the thermoelectric gel of the present invention;

[0058] Figure 2 This is a physical image of the flexible and malleable thermoelectric gel from Embodiment 3 of the present invention;

[0059] Figure 3 This is a schematic diagram of the high-temperature ion thermoelectric conversion device of the present invention;

[0060] Figure 4 This is a graph showing the relationship between the open-circuit voltage and temperature difference of the high-temperature ion thermoelectric conversion device of the present invention.

[0061] Figure 5 This is a bar chart showing the thermoelectric potential values ​​of the high-temperature ion thermoelectric conversion device of the present invention.

[0062] Figure 6 This is a graph showing the output power density of the high-temperature ion thermoelectric converter of the present invention.

[0063] Figure 7 This is an open-circuit voltage curve of the thermoelectric generator of the present invention;

[0064] Figure 8 This is a graph showing the output power density of the thermoelectric generator of the present invention.

[0065] in, Figure 3 In the diagram, 100 represents the electrode, 200 represents the mold, 300 represents the thermoelectric gel, and 400 represents the cavity. Detailed Implementation

[0066] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0067] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0068] The working mechanism of the graphene composite ion thermoelectric gel of this invention is as follows: when the thermoelectric gel and the electrode constitute a thermoelectric conversion device, the oxidation / reduction couple Fe(CN)64- and Fe(CN)6 3- Utilizing the thermoelectrochemical effect, an oxidation reaction Fe(CN)6 occurs at the hot end of the thermoelectric conversion device. 4- -e→Fe(CN)6 3- Electrons are released and accumulate on the hot-end electrode. These electrons then return to the cold end of the thermoelectric conversion device via the external circuit. At the cold-end electrode, electrons are received, and a reduction reaction, Fe(CN)6, occurs. 3- +e→Fe(CN)6 4- Oxidation and reduction products return to the counter electrode through diffusion. Simultaneously, graphene provides an "island-bridge" structure, accelerating ion diffusion and migration, enhancing the thermal diffusion effect of the redox couple ions, and improving the ionic thermoelectric potential and output power density of the thermoelectric gel. A schematic diagram of the working mechanism of the thermoelectric gel of this invention is shown below. Figure 1 As shown.

[0069] Example 1

[0070] A method for preparing a high-temperature graphene composite ionic thermogel includes the following steps:

[0071] (1) Weigh 3g of polyvinyl alcohol (final concentration 0.3g / mL), 0.2g of multilayer graphene (final concentration 0.02g / mL), 0.1330g of potassium ferricyanide (final concentration 0.04mol / L) and 0.0853g of potassium ferrocyanide (final concentration 0.02mol / L), add them to 10mL of water to obtain a mixture;

[0072] (2) The mixture obtained in step (1) is magnetically stirred at 300 rpm for 0.5 h at a temperature of 50 °C to ensure that the mixture is fully mixed. After cooling, a high-temperature graphene composite ionic thermoelectric gel is obtained.

[0073] Example 2

[0074] A method for preparing a high-temperature graphene composite ionic thermogel includes the following steps:

[0075] (1) Weigh 4g of carrageenan (final concentration 0.2g / mL), 0.4g of graphene oxide (final concentration 0.02g / mL), 0.6652g of sodium ferrocyanide (final concentration 0.1mol / L) and 1.7066g of sodium ferrocyanide (final concentration 0.2mol / L), add them to 20mL of propanol to obtain a mixture;

[0076] (2) The mixture obtained in step (1) is magnetically stirred at 800 rpm for 1.5 h at a temperature of 80°C to ensure that the mixture is fully mixed. After cooling, a high-temperature graphene composite ion thermoelectric gel is obtained.

[0077] Example 3

[0078] A method for preparing a high-temperature graphene composite ionic thermogel includes the following steps:

[0079] (1) Weigh 3g of gelatin (final concentration 0.4g / mL), 0.16g of graphene oxide (final concentration 0.02g / mL), 0.1596g of potassium ferricyanide (final concentration 0.06mol / L) and 0.1365g of potassium ferrocyanide (final concentration 0.04mol / L), add them to 8mL of water to obtain a mixture;

[0080] (2) The mixture obtained in step (1) is magnetically stirred at 600 rpm for 1 hour at a temperature of 70°C to ensure that the mixture is fully mixed. After cooling, a high-temperature graphene composite ion thermoelectric gel is obtained.

[0081] A physical image of the flexible and malleable thermoelectric gel of Embodiment 3 of the present invention is shown below. Figure 2 As shown. By Figure 2 It can be seen that the thermoelectric gel prepared by the present invention has good flexibility.

[0082] Example 4

[0083] A method for preparing a high-temperature graphene composite ionic thermogel includes the following steps:

[0084] (1) Weigh 2g of starch (final concentration 0.3g / mL), 0.24g of monolayer graphene (final concentration 0.04g / mL), 0.1596g of potassium ferricyanide (final concentration 0.08mol / L) and 0.1536g of potassium ferrocyanide (final concentration 0.06mol / L), add them to 6mL of methanol to obtain a mixture;

[0085] (2) The mixture obtained in step (1) is magnetically stirred at 800 rpm for 2 hours at a temperature of 80°C to ensure that the mixture is fully mixed. After cooling, a high-temperature graphene composite ion thermoelectric gel is obtained.

[0086] Example 5

[0087] A method for preparing a high-temperature graphene composite ionic thermogel includes the following steps:

[0088] (1) Weigh 5g of gelatin (final concentration 0.3g / mL), 0.75g of multilayer graphene (final concentration 0.05g / mL), 1.4966g of potassium ferricyanide (final concentration 0.3mol / L) and 0.9600g of potassium ferrocyanide (final concentration 0.15mol / L), add them to 15mL of water to obtain a mixture;

[0089] (2) The mixture obtained in step (1) is magnetically stirred at 800 rpm for 3 hours at a temperature of 70°C to ensure that the mixture is fully mixed. After cooling, a high-temperature graphene composite ion thermoelectric gel is obtained.

[0090] Application Example 1

[0091] A method for preparing a high-temperature ion thermoelectric conversion device includes the following steps:

[0092] The composite ion thermoelectric gel 300 prepared in Example 1 was injected into the cavity 400 of a 1×1×0.2cm square mold 200. Then, graphite paper electrodes 100 were used to cover the upper and lower ends of the mold 200, forming a sandwich structure of electrode sheet-thermoelectric gel-electrode sheet, thus obtaining a high-temperature ion thermoelectric converter device. A schematic diagram of the structure of the high-temperature ion thermoelectric converter device of the present invention is shown below. Figure 3 As shown, one electrode of the high-temperature ion thermoelectric conversion device is located at the hot end, and the other electrode is located at the cold end. The hot end and the cold end are tightly connected to the upper and lower electrodes. By controlling the temperature of the hot end and the cold end, different temperature differences can be achieved.

[0093] The high-temperature ion thermoelectric converter device prepared in Application Example 1 was subjected to different temperature differences at 30°C for its hot and cold ends, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 1. Figure 4 As shown; take Figure 4 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between output current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that as the temperature difference increases, the open-circuit voltage also increases. From... Figure 5 , 6 It can be seen that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 7.2 mV / K, and the maximum output power density is 0.52 mW / m³. -2 K -2 .

[0094] Application Example 2

[0095] The difference between Application Example 2 and Application Example 1 is that the composite ionic thermogel prepared in Example 2 is used, while the rest is the same as in Application Example 1.

[0096] The high-temperature ion thermoelectric converter device prepared in Application Example 2 was subjected to different temperature differences at 60°C for its hot and cold ends, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 2. Figure 4 As shown; take Figure 4 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between output current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that the open-circuit voltage increases with the increase of the temperature difference. From points 5 and 6, we know that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 3.6 mV / K, and the maximum output power density is 0.2 mW / m³. -2 K -2 .

[0097] Application Example 3

[0098] The difference between Application Example 3 and Application Example 1 is that the composite ionic thermogel prepared in Example 3 is used, while the rest is the same as in Application Example 1.

[0099] The high-temperature ion thermoelectric converter device prepared in Application Example 3 was subjected to different temperature differences at 50°C for its hot and cold ends, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 3. Figure 4 As shown; take Figure 4 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between output current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that as the temperature difference increases, the open-circuit voltage also increases. From... Figure 5 , 6 It can be seen that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 13 mV / K, and the maximum output power density is 1.02 mW / m³. -2 K -2 .

[0100] Application Example 4

[0101] The difference between Application Example 4 and Application Example 1 is that the composite ionic thermogel prepared in Example 4 is used, while the rest is the same as in Application Example 1.

[0102] The high-temperature ion thermoelectric converter device prepared in Application Example 4 was subjected to different temperature differences at 60°C, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 4. Figure 4 As shown; take Figure 4 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between output current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that as the temperature difference increases, the open-circuit voltage also increases. From... Figure 5 , 6 It can be seen that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 5mV / K, and the maximum output power density is 0.29mW / m³. -2 K -2 .

[0103] Application Example 5

[0104] The difference between Application Example 5 and Application Example 1 is that the composite ionic thermogel prepared in Example 5 is used, while the rest is the same as in Application Example 1.

[0105] The high-temperature ion thermoelectric converter device prepared in Application Example 5 was subjected to different temperature differences at 40°C, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 5. Figure 4 As shown; take Figure 4 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between output current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that as the temperature difference increases, the open-circuit voltage also increases. From... Figure 5 , 6 It can be seen that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 10.4 mV / K, and the maximum output power density is 0.67 mW / m. -2 K -2 .

[0106] Application Example 6

[0107] A high-temperature thermoelectric generator.

[0108] The four high-temperature ion thermoelectric conversion devices obtained in Application Example 3 were connected in series with graphite paper to form a high-temperature thermoelectric power generation device. In this device, one electrode of the high-temperature ion thermoelectric conversion device is located at the hot end, and the other electrode is located at the cold end. The hot end and the cold end are tightly connected to the upper and lower electrodes. By controlling the temperature of the hot end and the cold end, different temperature differences can be achieved.

[0109] The high-temperature thermoelectric generator was placed at 50°C, with a 3°C temperature difference applied between the hot and cold ends. The voltage, current, and output power density of the generator were then tested. The open-circuit voltage curve of the high-temperature thermoelectric generator is shown below. Figure 7 As shown; the output power density curve of the power generation device is as follows. Figure 8 As shown. By Figure 7 and Figure 8 It can be seen that the high-temperature thermoelectric generator prepared by this invention can achieve an open-circuit voltage of up to 120mV and a power output of 1.2mW. -2 K -2 The output power density is the highest reported to date for ion gel thermoelectric generators.

[0110] Comparative Example 1

[0111] The only difference between Comparative Example 1 and Example 3 is that Comparative Example 1 uses an equal amount of carbon fiber to replace the graphene oxide in Example 3, while the rest is the same as Example 3.

[0112] Comparative Example 2

[0113] The only difference between Comparative Example 2 and Example 3 is that Comparative Example 2 uses an equal amount of graphite to replace the graphene oxide in Example 3, while the rest is the same as Example 3.

[0114] Application Comparative Example 1

[0115] The difference between Comparative Example 1 and Application Example 3 is that Comparative Example 1 uses the composite ionic thermogel prepared in Comparative Example 1, while the rest is the same as Application Example 3.

[0116] The high-temperature ion thermoelectric converter device prepared using Comparative Example 1 was subjected to different temperature differences at 50°C for its hot and cold ends, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 1. Figure 4 As shown; take Figure 3 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that as the temperature difference increases, the open-circuit voltage also increases. From... Figure 5 , 6 It can be seen that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 2mV / K, and the maximum output power density is 0.1mW / m³. -2 K -2 The thermoelectric gel prepared using graphene oxide in Example 3, when applied to a high-temperature ion thermoelectric conversion device, exhibits superior performance in terms of ion thermoelectric potential and maximum output power density compared to the thermoelectric gel prepared using carbon fiber in Comparative Example 1.

[0117] Application Comparative Example 2

[0118] The difference between Comparative Example 2 and Application Example 3 is that Comparative Example 2 uses the composite ionic thermogel prepared in Comparative Example 2, while the rest is the same as Application Example 3.

[0119] The high-temperature ion thermoelectric converter device prepared in Comparative Example 2 was subjected to different temperature differences at 50°C for its hot and cold ends, and then the open-circuit voltage of the thermoelectric converter device was tested; the relationship curve between the open-circuit voltage and the temperature difference is shown in Figure 2. Figure 4 As shown; take Figure 3 The slope of the linear fit is the thermoelectric potential value, such as Figure 5 As shown; the curve showing the relationship between current and output power density is as follows. Figure 6 As shown. By Figure 4 It can be seen that as the temperature difference increases, the open-circuit voltage also increases. From... Figure 5 , 6It can be seen that the ion thermoelectric potential of the high-temperature ion thermoelectric conversion device is 3mV / K, and the maximum output power density is 0.15mW / m³. -2 K -2 The thermoelectric gel prepared using graphene oxide in Example 3, when applied to a high-temperature ion thermoelectric conversion device, exhibits superior performance in terms of ion thermoelectric potential and maximum output power density compared to the thermoelectric gel prepared using graphite in Comparative Example 2.

[0120] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A thermoelectric gel, characterized in that, Including gelled organic matrix, graphene, redox couple and solvent; The graphene forms an "island-bridge structure" in the thermoelectric gel, accelerating the diffusion and migration of ions in the redox couple.

2. The thermoelectric gel according to claim 1, characterized in that, The content of the gelled organic matrix is ​​0.001-0.55 g / mL; the content of the graphene is 0.001-0.11 g / mL; in the oxidation / reduction couple, the content of the oxidation couple is 0.0002-0.65 mol / L and the content of the reduction couple is 0.0001-0.33 mol / L.

3. The thermoelectric gel according to claim 1, characterized in that, The gelling organic matrix includes at least one of gelatin, polyvinyl alcohol, carrageenan, and starch.

4. The thermoelectric gel according to claim 1, characterized in that, The graphene includes at least one of monolayer graphene, multilayer graphene, and graphene oxide.

5. The thermoelectric gel according to claim 1, characterized in that, The oxidation / reduction couple includes at least one of potassium ferrocyanide / potassium ferrocyanide and sodium ferrocyanide / sodium ferrocyanide.

6. The thermoelectric gel according to claim 1, characterized in that, The solvent includes at least one of water, methanol, and propanol.

7. The thermoelectric gel according to claim 1, characterized in that, The thermogel operates in the temperature range of 20-150℃.

8. The method for preparing the thermoelectric gel according to any one of claims 1-7, characterized in that, Includes the following steps: The various raw material components are mixed to obtain a thermoelectric gel.

9. A thermoelectric conversion device, characterized in that, Includes electrodes and the thermoelectric gel according to any one of claims 1-7.

10. A thermoelectric power generation device, characterized in that, Includes the thermoelectric conversion device as described in claim 9.

Images