CN107768510A - A kind of electrothermal module and preparation method thereof - Google Patents

Abstract

The invention discloses a thermoelectric module and a preparation method thereof, and relates to the technical field of nanometer material thermoelectric conversion. The thermoelectric module includes a continuous flexible thermoelectric film, which has a plurality of P-type planar regions exhibiting P-type material characteristics and a plurality of N-type planar regions exhibiting N-type material characteristics, and a plurality of P-type planar regions and a plurality of N-type planar regions. The type planar regions are continuously and alternately distributed along the extension direction of the flexible thermoelectric film; wherein, the flexible thermoelectric film forms a compact structure along the extension direction in a substantially "W" shape or in a folded form wound in the same direction, and makes Any pair of adjacent P-type planar regions and N-type planar regions face each other, thereby forming a corresponding P-N junction unit; Between the planar area and the N-type planar area. The invention also provides a corresponding preparation method. The preparation method of the invention is simple, and the formed thermoelectric module has compact size and good performance.

Description

A kind of thermoelectric module and preparation method thereof

technical field

The invention relates to the technical field of nanometer material thermoelectric conversion, in particular to a thermoelectric module and a preparation method thereof.

Background technique

Thermoelectric modules composed of P-type and N-type thermoelectric materials can directly realize the mutual conversion of electric energy and thermal energy. In terms of thermoelectric power generation, thermoelectric modules can very effectively convert thermal energy generated from natural heat sources (such as solar energy or geothermal energy) and waste heat that is ubiquitous in industry and life into valuable electrical energy, and realize energy recycling. In terms of thermoelectric refrigeration, compared with traditional refrigerators, thermoelectric refrigeration will reduce the use of toxic chlorofluorocarbons and their substitutes, and reduce the weight, cost and energy consumption of refrigerators. At the same time, the thermoelectric module has a simple structure, no moving mechanical components, and no dangerous liquid or gas medium, so it works quietly, without noise, with high stability and without pollution. In today's increasingly serious environmental pollution and energy crisis, thermoelectric modules have broad application prospects and strong practical significance in the fields of thermoelectric power generation and thermoelectric refrigeration.

Contents of the invention

The inventors found that currently reported thermoelectric modules include flexible thermoelectric modules composed of polymers, carbon nanotubes, and carbon nanotube/polymer composite materials. When preparing the flexible thermoelectric module, it is necessary to prepare P-type and N-type thermoelectric legs respectively, and then electrically connect these thermoelectric legs in series through metal connecting wires. In addition, in order to reduce the contact resistance between the metal connecting wires and the thermoelectric legs, usually every Deposit tens of nanometers of gold or silver top electrode on a thermoelectric leg or smear silver glue on the thermoelectric leg. In this way, the preparation process of the thermoelectric module is not only cumbersome, but also the size is not compact enough. The inventors also found that when the thermoelectric module is in contact with the heat source, due to the space between the thermoelectric legs, these spaces cannot use the heat source, thus limiting the use of heat sources. Utilization of heat source.

At the same time, the inventors further found that in some current reports, for example, in 2011, the Crispin research group used the optimized PEDOT-Tos film as the p-type thermoelectric leg, and TTF-TCNQ as the n-type thermoelectric leg, and prepared 54 thermoelectric legs. The all-organic thermoelectric module has a power density of 0.27μW cm ^-2 under a temperature gradient of 30K (the power density is the power divided by the cross-sectional area of the entire module). In 2012, Zhu’s research group prepared n-type metal coordination polymer poly[Na _x (Ni-ett)] and p-type metal coordination polymer poly[ _Cux (Cu-ett)] on Al substrates The all-organic thermoelectric module containing 35 pairs of thermocouples has a power density of 2.8μW cm ^-2 at a temperature gradient of 30K. In 2015, Bazan's research group used conjugated polyelectrolyte/single-walled carbon nanotube (CPE/SWNT) composite film to prepare a radial thermoelectric module with 8 thermoelectric legs, which can realize the utilization of point heat source. Under the temperature gradient of 35K The magnitude of the generated power is 0.3nW. The reason why the output power and power density of the flexible thermoelectric module is small is that the power factor of the P-type or N-type flexible thermoelectric material constituting the module is not high, which greatly affects the thermoelectric conversion efficiency of the module.

Therefore, the object of the present invention is to provide a thermoelectric module, which has a simple preparation method, compact size, high performance, and high output power and power density.

Another object of the present invention is to provide a method for preparing a thermoelectric module, which is simple to operate, and the prepared thermoelectric module is compact in size, high in performance, and has relatively high output power and power density.

In particular, the present invention provides a thermoelectric module, comprising:

A continuous flexible thermoelectric film, which has a plurality of P-type planar regions exhibiting P-type material characteristics and a plurality of N-type planar regions exhibiting N-type material characteristics, the plurality of P-type planar regions and the plurality of N-type planar regions The planar regions are continuously and alternately distributed along the extension direction of the flexible thermoelectric film; wherein, the flexible thermoelectric film forms a compact structure in a substantially “W”-shaped fold along the extension direction, or the flexible thermoelectric film The folded form of the film winding in the same direction along the extending direction forms a compact structure, and makes any pair of adjacent P-type planar regions and N-type planar regions face each other, thereby forming a corresponding P-N junction unit; and

The insulating diaphragm is arranged between the P-type plane area and the N-type plane area facing each other in each P-N junction unit.

Further, each of the P-type planar regions and each of the N-type planar regions has substantially the same area and shape, so that adjacent P-type planar regions and N-type planar regions of the flexible thermoelectric film can be substantially overlap each other, and make the area of the main surface of the compact structure equal to the area of each of the N-type planar regions or P-type planar regions.

Further, the insulating diaphragm has substantially the same area and shape as the P-type planar region and the N-type planar region.

Further, the insulating diaphragm is flexible.

Further, the insulating diaphragm is heat-insulating.

Further, it also includes two electrodes for transmitting electrical signals, the two electrodes are respectively located at the two ends of the flexible thermoelectric film along its extending direction, and are composed of parts extending from the two ends; optionally , the two electrodes are external electrodes drawn from both ends of the flexible thermoelectric film along its extending direction, and the external electrodes are flexible or non-flexible.

Further, the flexible thermoelectric film is locally modified on a flexible base film to form the P-type planar region and/or the N-type planar region; optionally, the flexible base film is a continuous carbon Nanotube network, carbon nanotube film, graphene film, two-dimensional organic conductive network or two-dimensional organic conductive film, two-dimensional ultra-thin inorganic conductive network or two-dimensional ultra-thin inorganic conductive film.

Further, the material of the insulating diaphragm is selected from polyethylene terephthalate film, polyimide film, polydimethylsiloxane film, polymethyl methacrylate film, polyvinyl acetate film one or more of; or

The insulating diaphragm is a thin film with an insulating layer, and optionally, the material of the insulating layer is Si ₃ N ₄ or SiO ₂ .

In particular, the present invention also provides a method for preparing a thermoelectric module, comprising:

providing a flexible base film in an expanded state having an upper surface and a lower surface opposite the upper surface;

A plurality of P-type planar regions exhibiting P-type material characteristics and a plurality of N-type planar regions exhibiting N-type material characteristics are formed in the flexible base film to form a flexible thermoelectric film, the plurality of P-type planar regions and the plurality of N-type planar regions exhibiting N-type material characteristics The multiple N-type planar regions are continuously and alternately distributed along the extension direction of the flexible thermoelectric film;

The upper surface and the lower surface of the flexible thermoelectric film in the unfolded state are respectively covered with a corresponding first insulating diaphragm and a second insulating diaphragm; optionally, the first insulating diaphragm and the second insulating diaphragm The diaphragm is flexible;

folding the flexible thermoelectric thin film together with the first insulating membrane and the second insulating membrane into a compact structure along the extending direction in a substantially "W" shape or in a form of winding in the same direction, Any pair of adjacent P-type planar regions and N-type planar regions face each other and are separated by the first insulating membrane or the second insulating diaphragm, thereby forming corresponding P-N junction units.

Further, the P-type planar region and/or the N-type planar region are formed by locally modifying the flexible base film.

Further, the first insulating membrane and/or the second insulating membrane extend continuously on the plurality of P-type planar regions and the plurality of N-type planar regions.

Further, the first insulating diaphragm is a first plurality of diaphragm segments separated from each other, and the first plurality of diaphragm segments respectively cover the corresponding plurality of P-type plane regions or the corresponding plurality of N-type plane regions. area.

Further, after the first plurality of diaphragm segments respectively cover the corresponding plurality of P-type planar regions or the corresponding plurality of N-type planar regions, using the first plurality of diaphragm segments as a mask, performing the local modification on the uncovered regions of the flexible base film to obtain the plurality of N-type planar regions or the plurality of P-type planar regions.

Further, the second insulating diaphragm is a second plurality of diaphragm segments separated from each other, and the second plurality of diaphragm segments respectively cover the corresponding plurality of P-type plane regions or the corresponding plurality of N-type plane regions. area.

Further, it also includes: before performing the folding, providing two electrodes for transmitting electrical signals, the two electrodes are respectively located at the two ends of the flexible thermoelectric film along its extending direction, and the two ends An extended part; optionally, the two electrodes are external electrodes drawn from both ends of the flexible thermoelectric film along its extending direction, and the external electrodes are flexible or non-flexible.

Further, the flexible base film is a continuous carbon nanotube network, a carbon nanotube film, a graphene film, a two-dimensional organic conductive network or a two-dimensional organic conductive film, a two-dimensional ultra-thin inorganic conductive network or a two-dimensional ultra-thin inorganic conductive film. film.

Further, the material of the insulating diaphragm is selected from polyethylene terephthalate film, polyimide film, polydimethylsiloxane film, polymethyl methacrylate film, polyvinyl acetate film one or more of; or

The insulating diaphragm is a thin film with an insulating layer, and optionally, the material of the insulating layer is Si ₃ N ₄ or SiO ₂ .

The inventors found that by forming continuous and alternately distributed P-type planar regions and N-type planar regions in the flexible base film, and forming the thermoelectric module by folding, not only the preparation method is simple and feasible, but also the formed thermoelectric module is compact in size, It can make full use of the heat source, has better performance, can greatly increase the output power, and at the same time has a higher power density.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of illustration and not limitation with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. In the attached picture:

Fig. 1 is a schematic structural diagram of a thermoelectric module deployed according to an embodiment of the present invention;

Fig. 2 is a schematic sectional view along line c-c in Fig. 1;

Fig. 3 is a simplified schematic diagram of the "W"-shaped folded form of Fig. 2;

Fig. 4 is a simplified schematic diagram of the winding and folding form of Fig. 2;

Fig. 5 is a schematic flow diagram of Fig. 1 being folded into a thermoelectric module;

6 is a schematic flow diagram of a method for preparing a thermoelectric module according to an embodiment of the present invention;

Fig. 7 is a simple schematic diagram of a thermoelectric module in a "W" shape when unfolded according to another embodiment of the present invention;

Fig. 8 is a simple schematic diagram of a thermoelectric module unfolded in a "W" shape according to yet another embodiment of the present invention;

Fig. 9 is a simple schematic diagram of a thermoelectric module in a "W" shape when unfolded according to other embodiments of the present invention;

Fig. 10 is a voltage output diagram of the flexible thermoelectric module in Example 1 under different steady-state temperature differences;

Fig. 11 is the voltage-current curve and power-current curve of the flexible thermoelectric module in Example 1 when the hot end temperature is 330K and the temperature difference is 27.5K.

Detailed ways

In one embodiment of the present invention, as shown in FIG. 1, the thermoelectric module includes a continuous flexible thermoelectric film 12, which has a plurality of P-type planar regions 15 exhibiting P-type material properties and multiple P-type planar regions 15 exhibiting N-type material properties. N-type planar regions 16, the plurality of P-type planar regions 15 and the plurality of N-type planar regions 16 are continuously and alternately distributed along the extension direction of the flexible thermoelectric film 12; it can be understood that FIG. The three-dimensional structure diagram of the thermoelectric module when unfolded, not only has the length and width along the plane, but also has the thickness deep inside the plane. Wherein, the flexible thermoelectric film 12 forms a compact structure in a substantially "W"-shaped folded form along the extending direction, or the flexible thermoelectric film is formed in a folded form wound in the same direction along the extending direction A compact structure, as shown in Figure 2, Figure 3, Figure 4 and Figure 5, and makes any pair of adjacent P-type planar regions 15 and N-type planar regions 16 face each other, thereby forming a corresponding P-N junction unit and an insulating diaphragm disposed between the P-type planar region 15 and the N-type planar region 16 facing each other in each P-N junction unit.

Here, the P-type material may be a P-type semiconductor material, and the N-type material may be an N-type semiconductor material. The plurality of P-type planar regions 15 and the plurality of N-type planar regions 16 are continuous and alternately distributed along the extension direction of the flexible thermoelectric film 12. "Continuous" refers to each P-type planar region 15 and each There is no gap between the N-type planar regions 16 . FIG. 4 schematically shows the compact structure formed by the flexible thermoelectric thin film 12 in the form of rolling and folding along the upper right side in the direction of the drawing. Meanwhile, the insulating membrane may include a first insulating membrane 14 and a second insulating membrane 11 .

Further, in order to make the size of the thermoelectric module compact, each of the P-type planar regions 15 and each of the N-type planar regions 16 has substantially the same area and shape, so that the phase of the flexible thermoelectric film 12 Adjacent P-type planar regions 15 and N-type planar regions 16 can substantially overlap each other and make the main surface of the compact structure have the area of each of said N-type planar regions 16 or P-type planar regions 15 . In this way, there will be no space in the thermoelectric module, so the heat source can be fully utilized.

Meanwhile, as shown in FIG. 1 , the insulating membrane has substantially the same area and shape as the P-type planar region 15 and the N-type planar region 16 . The insulating membrane can be flexible, so that the insulating membrane can be easily deformed and folded when it is folded, and the insulating membrane can also cover the P-type plane region 15 or the N-type plane region 16 more obediently. At the same time, the insulating membrane can also be heat-insulating.

Further, as shown in FIG. 1 , the thermoelectric module may also include two electrodes 130 for transmitting electrical signals, the two electrodes are respectively located at the two ends of the flexible thermoelectric film 12 along its extending direction, and are formed by The parts extending from the two ends; optionally, the two electrodes 130 are external electrodes drawn from both ends of the flexible thermoelectric film 12 along its extending direction, so that the electrodes 130 are attached to the flexible thermoelectric film 12 The two ends of the flexible thermoelectric film 12 are used to paste the electrodes 130 with silver glue 131 to transmit electrical signals. The external electrodes 130 can be flexible, such as carbon nanotube fibers with flexible wires. In this way, the thermoelectric module formed is flexible as a whole, which is convenient for carrying and easy to attach to the surface of other objects. The external electrodes can also be non-flexible, such as silver wires and copper wires. In this way, the thermoelectric module is flexible, and only the electrodes are non-flexible, which facilitates signal detection.

Further, the flexible thermoelectric film 12 is partially modified on a flexible base film to form the P-type planar region 15 and/or the N-type planar region 16; optionally, the flexible base film It can be continuous carbon nanotube network, carbon nanotube film, graphene film, two-dimensional organic conductive network or two-dimensional organic conductive film, two-dimensional ultra-thin inorganic conductive network or two-dimensional ultra-thin inorganic conductive film.

In one embodiment of the present invention, the material of the insulating diaphragm is selected from polyethylene terephthalate (PET) film, polyimide (PI) film, polydimethylsiloxane (PDMS) film , polymethyl methacrylate (PMMA) film, polyvinyl acetate (PVA) film in one or more; The diaphragm material of described first insulating diaphragm 14 and described second insulating diaphragm 11 can be identical, also can can be different. Alternatively, the insulating diaphragm may be a film with an insulating layer, and optionally, the material of the insulating layer may be Si ₃ N ₄ or SiO ₂ .

In particular, the present invention also provides a method for preparing a thermoelectric module, as shown in Figure 6, which may include the following steps:

S100, providing a flexible base film in an unfolded state, which has an upper surface and a lower surface opposite to the upper surface;

S200, forming a plurality of P-type planar regions exhibiting P-type material characteristics and a plurality of N-type planar regions exhibiting N-type material characteristics in the flexible base film to form a flexible thermoelectric film, the plurality of P-type planar regions and the plurality of N-type planar regions are continuously and alternately distributed along the extension direction of the flexible thermoelectric film;

S300, covering the upper surface and the lower surface of the flexible thermoelectric film in the unfolded state with corresponding first insulating membranes and second insulating membranes respectively; optionally, the first insulating membrane and the second insulating membrane 2. The insulating diaphragm is flexible;

S400. Fold the flexible thermoelectric film together with the first insulating membrane and the second insulating membrane into a compact shape along the extension direction in a substantially “W” shape or in a form of winding in the same direction. structure, so that any pair of adjacent P-type planar regions and N-type planar regions face each other, and are separated by the first insulating membrane or the second insulating diaphragm, thereby forming corresponding P-N junction units.

In one embodiment of the present invention, according to the actual preparation situation, the order of step S200 and step S300 can be exchanged, so that after the upper surface and the lower surface of the flexible base film are respectively covered with an insulating diaphragm, the insulating diaphragm can also be used as When the mask plate is used, when the flexible base film is modified, the part covered by the mask plate maintains the P-type characteristics of the flexible base film, while the part not covered by the mask plate can be modified so that the part It exhibits N-type characteristics. Of course, in order to highlight the P-type or N-type characteristics of the flexible thermoelectric film 12 itself, before covering the mask plate, a post-processing method can also be used to further strengthen the P-type or N-type characteristics, so that To improve the performance of the thermoelectric module.

Specifically, the P-type planar region and/or the N-type planar region are formed by locally modifying the flexible base film. As shown in FIG. 7 , the first insulating membrane 14 and/or the second insulating membrane 11 may extend continuously on the plurality of P-type planar regions and the plurality of N-type planar regions. As shown in FIG. 8 and FIG. 9, the first insulating diaphragm 14 is a first plurality of diaphragm segments separated from each other, and the first plurality of diaphragm segments respectively cover the corresponding plurality of P-type plane regions or the corresponding The plurality of N-type planar regions. Fig. 7, Fig. 8 and Fig. 9 show the distribution position of the flexible thermoelectric film 12 and the insulating diaphragm in the folded form of "W", it can be understood that the insulation at the flexible thermoelectric film 12 in the folded form wound in the same direction The distribution position of the diaphragm can also be distributed as shown in Figure 7 and Figure 8, and it can also be understood that, in the folding process, as long as there is an insulating diaphragm between the P-type plane area and the N-type plane area facing each other, then This type of distribution of insulating diaphragms is permissible.

By arranging the insulating diaphragm, it is possible to prevent the contact between the P-type region and the N-type region when the flexible thermoelectric film 12 is folded. Therefore, after the folding is completed, a structure in which the P-type region and the N-type region are connected in series is formed inside the entire module. When the module is working, the voltage generated by applying temperature difference in each area can be superimposed. If no insulating diaphragm is provided, then when the flexible thermoelectric film 12 is folded, the P-type region and the N-type region will be in face-to-face contact. After the folding is completed, the whole body is equivalent to a conductor with a certain thickness. Reduce the final output voltage. On the other hand, the modified area is in contact with the P-type area and the N-type area formed by the unmodified area. The modified substance existing on the modified area will also change the properties of the unmodified area. If the N-type region is in contact with the P-type region, it is possible that the residual dopant on the N-type region will weaken or convert the P-type of the P-type region to N-type. In this case, it will also affect to a certain extent final output voltage.

In one embodiment of the present invention, after the first plurality of diaphragm segments respectively cover the corresponding plurality of P-type planar regions or the corresponding plurality of N-type planar regions, the first plurality of diaphragms The section serves as a mask to perform the local modification on the uncovered regions of the flexible base film, so as to obtain the plurality of N-type planar regions or the plurality of P-type planar regions. Here, the modification may include drop casting, spin coating, spray coating, printing, thermal evaporation, electron beam evaporation, vapor deposition or magnetron sputtering of N-type or P-type dopants at the flexible thermoelectric thin film 12 to N-type or P-type regions are formed.

Further, as shown in FIG. 8 or FIG. 9, the second insulating diaphragm 11 is a second plurality of diaphragm segments separated from each other, and the second plurality of diaphragm segments respectively cover the corresponding plurality of P-type plane regions. Or the corresponding plurality of N-type planar regions.

In one embodiment of the present invention, before the folding, two electrodes for transmitting electrical signals are provided, the two electrodes are respectively located at the two ends of the flexible thermoelectric film along its extending direction, and are formed by the The parts extending from both ends; optionally, the two electrodes are external electrodes drawn from both ends of the flexible thermoelectric film along its extending direction, and the external electrodes are flexible or non-flexible.

By forming continuous and alternately distributed P-type planar regions and N-type planar regions in the flexible base film, and forming the thermoelectric module by folding, not only the preparation method is simple and feasible, but also the formed thermoelectric module is compact in size and can make full use of the heat source , The performance is better, the output power can be greatly improved, and the power density is also larger.

The beneficial effects of the present invention will be further described below in conjunction with more specific embodiments.

Example 1: A flexible thermoelectric module is prepared based on a directly grown large-area P-type carbon nanotube film and an N-type dopant.

S100, using the improved floating catalytic chemical vapor deposition method to directly grow large-area carbon nanotube films, the performance is significantly better than that of carbon nanotube films prepared from dispersed carbon nanotube solutions. The pristine carbon nanotube film shows P-type characteristics due to the doping of oxygen in the air;

S200, cutting out carbon nanotube strips (that is, flexible thermoelectric film 12 ) from the large-area carbon nanotube film and placing them on the PET substrate, the PET substrate is used as the second insulating diaphragm 11 to completely cover the entire carbon nanotube film. Adhere some PET double-sided adhesives at a certain distance on the carbon nanotube strip as the first insulating diaphragm 14, press to make it closely contact with the strip;

S300, using silver glue 131 on both ends of the carbon nanotube strip to stick the flexible wire carbon nanotube fiber as the electrode 130 to lead out the electrical signal;

S400, use a pipette gun to drip-cast an N-type dopant (1 wt.% polyethyleneimine solution) on the unshielded area of the carbon nanotube strip, and then dry it at 50° C. for 5 minutes. Then the area covered by the PET double-sided adhesive 14 on the carbon nanotube strip remains P-type, and the unshielded area is doped into N-type, and continuous and alternately distributed P-type planar areas and N-type plane area;

In S500, a flexible continuous thermoelectric module is formed by folding carbon nanotube strips multiple times along the connecting line of the P-type plane area and the N-type plane area.

When one end of the flexible thermoelectric module prepared above is heated, a temperature gradient (ΔT=T _hot -T _cold ) will be generated at both ends of the module along the in-plane direction. Due to the Seebeck effect, a significant thermal voltage will be ensues.

Figure 10 is the voltage output diagram of the flexible thermoelectric module under different steady-state temperature differences. As shown in Figure 10, as the temperature difference between the two ends of the module increases, the generated voltage also increases linearly. Through the slope of the linear fitting curve, we can get The flexible thermoelectric module has a large thermal electromotive force: 410μV K ^-1 .

Generally, when testing the output power of a thermoelectric module at room temperature, it is more valuable to select a temperature difference of about 30K, because a temperature difference of less than 30K is easy to obtain from the natural environment. Figure 11 shows that the temperature of the flexible thermoelectric module at the hot end is 330K, and the temperature difference is 27.5 Voltage-current curve and power-current curve at K. It can be concluded from Fig. 11 that the flexible thermoelectric module has a small internal resistance R ₀ =12.5Ω, an open circuit voltage V _oc of 11.3 mV, a short circuit current I _sc of 0.9 mA, a maximum output power of 2.51 μW, and a power density of 167μW cm ^-2 (the power density is calculated by dividing the power by the cross-sectional area of the entire module, including the thickness of the PET double-sided adhesive diaphragm). From the above analysis results, it can be seen that the performance of the flexible thermoelectric module is significantly better than that of the previously reported flexible thermoelectric devices under similar temperature differences.

Example 2: A flexible thermoelectric module was prepared based on a carbon nanotube film prepared from a P-type dispersed carbon nanotube solution and an N-type dopant.

S100, preparing a large-area carbon nanotube film by vacuum filtering the dispersed carbon nanotube solution. Similarly, untreated carbon nanotubes will show P-type characteristics due to the doping of oxygen in the air;

In S200, the large-area carbon nanotube film is soaked in concentrated nitric acid for 5 hours, and then rinsed repeatedly with deionized water, so that the P-type characteristics of the original carbon nanotube film are enhanced. After drying, a mask plate is set on the selected area of the carbon nanotube film, and an N-type dopant (2wt.% bibenzylpyridine solution) is sprayed on the unshielded area of the mask plate, and then baked at 60°C Let dry for 10 minutes. Then the area covered by the mask on the carbon nanotube film remains P-type, and the unshielded area is doped into N-type, and continuous and alternately distributed P-type planar regions and N-type planar regions are rapidly formed on the carbon nanotube film. ;

S300, using silver glue to glue silver wires on both ends of the carbon nanotube film to lead out electrical signals;

S400, as shown in FIG. 8, a PDMS film is set under the carbon nanotube film forming continuous and alternately distributed P-type planar regions and N-type planar regions as a second insulating diaphragm, covering only the N-type planar regions; Set the PDMS film as the first insulating diaphragm, covering only the P-type plane area;

In S500, a flexible continuous thermoelectric module is formed by folding the carbon nanotube film several times along the connecting line of the P-type plane area and the N-type plane area.

Example 3: A flexible thermoelectric module is prepared based on a dispersed graphene film prepared from a reduced graphene oxide solution and an N-type dopant.

S100, spin-coating and dispersing the reduced graphene oxide solution to prepare a large-area graphene multilayer film. Pristine graphene multilayer films exhibit p-type properties;

S200, a mask is set on the selected area of the large-area graphene multilayer film, and the alkali metal potassium is thermally evaporated on the unshielded area of the mask. Potassium has strong reducing properties and can be used as N-type doping of graphene agent. Then the area covered by the mask plate on the large-area graphene multilayer film remains P-type, and the unshielded area is doped with potassium to become N-type, and continuous and alternately distributed P-type planar regions and N-type plane area;

S300, extending a part of the two ends of the large-area graphene multilayer film as an electrode for extracting electrical signals;

S400, a PVA film is placed under the large-area graphene multilayer film forming continuous and alternately distributed P-type plane regions and N-type plane regions as the second insulating diaphragm, covering only the N-type plane region; The first insulating diaphragm covers only the P-type plane area;

In S500, a flexible continuous thermoelectric module is formed by folding a large-area graphene multilayer film multiple times along the connection line between the P-type plane region and the N-type plane region.

Example 4: A flexible thermoelectric module is prepared based on a directly grown P-type graphene film and an N-type dopant.

S100, large-area graphene films can be directly grown on copper foil by floating catalytic chemical vapor deposition;

S200, transferring a large-area graphene film from the copper foil to a PDMS substrate, the PDMS substrate is used as a second insulating diaphragm, completely covering the entire graphene film; adhering several PMMA films at a certain distance on the graphene film, PMMA film as the first insulating diaphragm;

S300, using silver glue to glue copper wires on both ends of the large-area graphene film to lead out electrical signals;

S400, print N-type dopant (5wt.% triphenylphosphine solution) with inkjet on the unshielded area of the large-area graphene film, and then dry at 60° C. for 5 minutes. Then the area covered by the PMMA film on the large-area graphene film remains P-type, and the un-shielded area is doped into N-type, and continuous and alternately distributed P-type plane areas and N-type plane areas are rapidly formed on the large-area graphene film. area

In S500, a flexible continuous thermoelectric module is formed by folding a large-area graphene film multiple times along the connection line between the P-type plane region and the N-type plane region.

Example 5: Fabrication of a flexible thermoelectric module based on a directly grown N-type carbon nanotube film and a P-type dopant.

S100, in the process of chemical vapor deposition, through the gas source of heteroatoms, N or P atoms can be introduced into the sidewall of carbon nanotubes to prepare large-area N-type carbon nanotube films;

S200, place a large-area carbon nanotube multilayer film on a canvas substrate, and the canvas substrate serves as a second insulating diaphragm to completely cover the entire carbon nanotube film; deposit SiN _x shielding on a selected area of the carbon nanotube film layer, as the first insulating diaphragm;

S300, extending a part of the two ends of the large-area carbon nanotube film as an electrode for extracting electrical signals;

S400, drop-casting a P-type dopant (30 wt.% hydrogen peroxide solution) on the unshielded area of the carbon nanotube film, and then drying at 50° C. for 5 minutes. Then the parts of the carbon nanotube film that are blocked by SiN _x keep N-type, and the parts that are not blocked are doped into P-type, and continuous and alternately distributed P-type planar regions and N-type planar regions are rapidly formed on the carbon nanotube film.

In S500, a flexible continuous thermoelectric module is formed by folding the carbon nanotube film several times along the connecting line of the P-type plane area and the N-type plane area.

Example 6: Two-step modification of the degassed carbon nanotube film to prepare a flexible thermoelectric module.

S100, put the large-area carbon nanotube film prepared by floating catalytic chemical vapor deposition into the glove box, and irradiate it with ultraviolet light to desorb the oxygen adsorbed on the carbon nanotube, and the treated large-area carbon nanotube film The tube film does not have P-type and N-type characteristics;

S200, placing the processed large-area carbon nanotube film on the elastic stocking substrate, and the elastic stocking is used as a second insulating diaphragm to completely cover the entire carbon nanotube film; set on a selected area of the large-area carbon nanotube film Mask plate, drop-cast P-type dopant (10M nitric acid solution) on the unshielded area of the mask plate, and then dry it at 50°C for 5 minutes, then the unshielded area of the mask plate is doped into P type;

S300, then covering the P-type plane area with PET double-sided adhesive, and the PET double-sided adhesive serves as a first insulating diaphragm. Remove the previously set mask plate, drop-cast N-type dopant (1wt.% polyethyleneimine solution) on the area covered in S200, then dry at 50°C for 5 minutes, then carbon nanotube film Continuous and alternately distributed P-type planar regions and N-type planar regions are formed;

S400, carbon nanotube fibers are glued on both ends of the large-area carbon nanotube film with silver glue to lead out electrical signals;

In S500, a flexible continuous thermoelectric module is formed by folding the carbon nanotube film several times along the connecting line of the P-type plane area and the N-type plane area.

So far, those skilled in the art should appreciate that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, the disclosed embodiments of the present invention can still be used. Many other variations or modifications consistent with the principles of the invention are directly identified or derived from the content. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (15)

1. a kind of electrothermal module, including：

Continuous flexible thermal electric film, there are multiple p-type plane domains that P-type material characteristic is presented in it and n type material is presented Multiple N-type plane domains of characteristic, the multiple p-type plane domain and the multiple N-type plane domain are along the flexible thermoelectricity The bearing of trend of film is continuous and is alternately distributed；Wherein, the flexible thermal electric film along the bearing of trend be substantially " W " The folded form of shape forms a compact structure, or the flexible thermal electric film is wound along the bearing of trend with same direction Folded form formed a compact structure, and cause it is any adjacent p-type plane domain and N-type plane domain are faced each other, So as to form corresponding P-N junction unit；And

Insulation diaphragm, it is arranged between opposed facing the p-type plane domain and N-type plane domain in each P-N junction unit.

2. electrothermal module according to claim 1, it is characterised in that each p-type plane domain and each N-type Plane domain has essentially identical area and shape, to cause the adjacent p-type plane domain of the flexible thermal electric film and N-type Plane domain can be substantially overlapped, and makes the area on the main surface of the compact structure be each N-type plane Region or the area of p-type plane domain.

3. electrothermal module according to claim 2, it is characterised in that the insulation diaphragm has and the p-type plane area Domain and the essentially identical area of the N-type plane domain and shape.

4. according to the electrothermal module any one of claim 1-3, it is characterised in that the insulation diaphragm is flexible.

5. according to the electrothermal module any one of claim 1-4, it is characterised in that the insulation diaphragm is heat-insulated.

6. according to the electrothermal module any one of claim 1-5, it is characterised in that also include for transmitting telecommunication number Two electrodes, described two electrodes extend along the both ends in direction positioned at the flexible thermal electric film respectively, and by the both ends The part composition extended；Alternatively, described two electrodes are that to extend along direction double-end for the flexible thermal electric film External electrode, it is the dispatch from foreign news agency extremely flexibility or non-flexible.

7. according to the electrothermal module any one of claim 1-6, it is characterised in that the flexible thermal electric film is one Partial modification is carried out on flexible foundation film to form the p-type plane domain and/or the N-type plane domain；Alternatively, The flexible foundation film be continuous carbon nano-tube network, carbon nano-tube film, graphene film, two-dimentional organic conductive network or Two-dimentional electroconductive organic film, two-dimensional ultrathin inorganic conductive network or two-dimensional ultrathin inorganic conductive film.

8. according to the electrothermal module any one of claim 1-7, it is characterised in that the material of the insulation diaphragm is selected from Pet film, Kapton, polydimethylsiloxanefilm film, polymethyl methacrylate are thin One or more in film, polyvinyl acetate ester film；Or

The insulation diaphragm is the film with insulating barrier, and alternatively, the material of the insulating barrier is Si₃N₄Or SiO₂。

9. a kind of preparation method of electrothermal module, including：

A flexible foundation film for being in deployed condition is provided, it has upper surface and the following table relative with the upper surface Face；

Formed in the flexible foundation film with multiple p-type plane domains that P-type material characteristic is presented and n type material is presented Multiple N-type plane domains of characteristic are to form flexible thermal electric film, the multiple p-type plane domain and the multiple N-type plane Bearing of trend of the region along the flexible thermal electric film is continuous and is alternately distributed；

It is covered each by the upper surface of the flexible thermal electric film in the deployed condition and the lower surface correspondingly The first insulation diaphragm and the second insulation diaphragm；Alternatively, first insulation diaphragm and the second insulation diaphragm are flexible；

By the flexible thermal electric film together with first insulation diaphragm and second insulation diaphragm along the bearing of trend A compact structure is folded into the form of being substantially " W " shape or in the form of same direction is wound so that any to adjacent P-type plane domain and N-type plane domain face each other, and by first insulation diaphragm or second insulation diaphragm by it Be spaced apart, so as to P-N junction unit corresponding to being formed.

10. preparation method according to claim 9, it is characterised in that the p-type plane domain and/or the N-type plane Region is formed by carrying out partial modification on the flexible foundation film.

11. preparation method according to claim 10, it is characterised in that first insulation diaphragm and/or described second Insulation diaphragm continuously extends on the multiple p-type plane domain and the multiple N-type plane domain.

12. preparation method according to claim 11, it is characterised in that first insulation diaphragm is the separated each other Individual diaphragm section more than one, individual diaphragm section more than described first are covered each by corresponding the multiple p-type plane domain or corresponding institute State multiple N-type plane domains.

13. preparation method according to claim 12, it is characterised in that be covered each by pair in more than described first individual diaphragm sections After the multiple p-type plane domain or corresponding the multiple N-type plane domain answered, by more than described first individual diaphragm sections As mask, the partial modification is carried out to the region of its unlapped flexible foundation film, to obtain the multiple N Type plane domain or the multiple p-type plane domain.

14. the preparation method according to claim 10 or 12, it is characterised in that second insulation diaphragm is to separate each other More than second individual diaphragm sections, individual diaphragm section more than described second be covered each by corresponding to the multiple p-type plane domain or correspondingly The multiple N-type plane domain.

15. according to the preparation method any one of claim 10-14, it is characterised in that also include：Carrying out the folding Before folded, there is provided for two electrodes of transmitting telecommunication number, described two electrodes respectively positioned at the flexible thermal electric film along its The both ends of bearing of trend, and the part extended by the both ends forms；Alternatively, described two electrodes are the flexible thermoelectricity Film extends along the double-end external electrode in direction, the dispatch from foreign news agency extremely flexibility or non-flexible.