阅读说明：本技术 一种具有电压匹配的光伏热电一体化器件及其制备方法 (Photovoltaic thermoelectric integrated device with voltage matching function and preparation method thereof ) 是由 李国强 邓曦 刘兴江 王文樑 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种具有电压匹配的光伏热电一体化器件及其制备方法。所述光伏热电一体化器件,其结构自上而下依次为：光伏电池、导电连接层、热电冷却器、导热连接层和温差电池,其中热电器件集成在光伏电池背面。本发明利用光照下光伏电池片产生的热能转化为电能,具有更高的能量利用效率,能充分利用光伏过程中的废热进行温差发电,通过串联光伏电池和热电冷却器既能给光伏电池降温,保证光伏电池热稳定性,又能使温差电池处保持较大温差,总体器件的能量转化效率,光伏电池和温差电池并联保证二者具有电压匹配。(The invention discloses a photovoltaic thermoelectric integrated device with voltage matching and a preparation method thereof. The photovoltaic thermoelectric integrated device sequentially comprises the following structural components from top to bottom: the thermoelectric device comprises a photovoltaic cell, an electric conduction connecting layer, a thermoelectric cooler, a heat conduction connecting layer and a thermoelectric cell, wherein the thermoelectric device is integrated on the back surface of the photovoltaic cell. The photovoltaic cell and the thermoelectric cooler are connected in series, so that the photovoltaic cell can be cooled, the thermal stability of the photovoltaic cell is ensured, a larger temperature difference can be kept at the thermoelectric cell, the energy conversion efficiency of the overall device is improved, and the photovoltaic cell and the thermoelectric cell are connected in parallel to ensure that the photovoltaic cell and the thermoelectric cell have voltage matching.)

1. A photovoltaic thermoelectric integrated device with voltage matching is characterized in that the structure of the device sequentially comprises from top to bottom: the solar cell comprises a photovoltaic cell, a conductive connecting layer, a thermoelectric cooler, a heat-conducting connecting layer and a thermoelectric cell;

one side of the conductive connecting layer is adhered to the back electrode surface of the photovoltaic cell, the other side of the conductive connecting layer is adhered to the cold end of the thermoelectric cooler, and the hot end of the thermoelectric cooler is fixedly adhered to the hot end of the thermoelectric cell through the conductive connecting layer.

2. The PV-thermoelectric integrated device with voltage matching as claimed in claim 1, wherein the external lead of the thermoelectric cooler is connected to the back electrode of the PV cell via an electrically conductive connection layer, such that the thermoelectric cooler and the PV cell are connected in series.

3. The pv-te integrated device with voltage matching according to claim 1, wherein the thermoelectric cell is connected in parallel with both the pv cell and the thermoelectric cooler.

4. The PV-MEMS device with voltage matching of claim 1, wherein the thermoelectric cooler is internally connected with P-type and N-type thermoelectric arm pairs by copper foils to form a P-N-P-N series thermoelectric arm circuit, and the thermoelectric cell is internally connected with P-type and N-type thermoelectric arm pairs by copper foils to form a P-N-P-N series thermoelectric arm circuit.

5. The integrated photovoltaic-thermoelectric device with voltage matching according to claim 1, wherein the conductive connection layer is connected to the back electrode of the photovoltaic cell and the cold side of the thermoelectric cooler by a conductive silver paste.

6. The PV-MEMS device with voltage matching of claim 1, wherein the PV cell is a Si-based thin film solar cell or GaAs thin film solar cell; the thermoelectric cooler and the thermoelectric cell are both thermocouple packaging devices.

7. The PV-thermoelectric integrated device with voltage matching as claimed in claim 1, wherein the conductive connection layer is made of at least one of metal thin film, semiconductor nano conductive thin film and graphene two-dimensional thin film, and the conductive connection layer is made of at least one of silicone grease, silicone gel, phase change material, phase change metal glue, heat sink and heat conductive glue.

8. The photovoltaic-thermoelectric integrated device with voltage matching as claimed in claim 7, wherein the conductive connection layer is made of a metal thin film made of at least one material selected from gold, silver, copper, chromium and nickel; the heat conductivity coefficient range of the heat-conducting connecting layer material is 0.1-50 W.m^-1·K^-1。

9. A method for preparing a photovoltaic-thermoelectric integrated device with voltage matching according to any one of claims 1 to 8, comprising the steps of:

(1) bonding and fixing the back electrode surface of the photovoltaic cell and the conductive connecting layer by silver paste, and integrating the thermoelectric cooler on the conductive connecting layer by the silver paste;

(2) coating a heat-conducting connecting layer on the thermoelectric cooler, and integrating the thermoelectric cell at the hot end of the thermoelectric cooler through the heat-conducting connecting layer;

(3) connecting the negative electrode-conductive connecting layer of the photovoltaic cell with the thermoelectric cooler through a lead so as to connect the photovoltaic cell with the thermoelectric cooler in series; connecting the thermoelectric cell and the photovoltaic cell-thermoelectric cooler in parallel to form a voltage-matched parallel circuit;

(4) and packaging the solar cell into a photovoltaic and thermoelectric integrated cell.

10. The method according to claim 9, wherein the electrically conductive connection layer of step (1) and the thermally conductive connection layer of step (2) are respectively disposed on two sides of the thermoelectric cooler; and (4) the packaging material is ethylene-vinyl acetate copolymer.

Technical Field

The invention belongs to the field of photovoltaic thermal devices, and particularly relates to a photovoltaic thermoelectric integrated device with voltage matching and a preparation method thereof.

Background

In recent years, with the growing severity of energy shortage, the development of clean and environment-friendly new energy and new energy conversion mode integration have become the focus of attention of researchers at present. The solar photovoltaic power generation technology has the advantages of environmental friendliness, high reliability, wide energy source distribution and the like, and is widely applied to the fields of satellites, centralized power generation, civil commodities and the like. However, the photovoltaic cell can only absorb energy in a band with energy higher than the forbidden bandwidth of the solar cell material, mainly, ultraviolet and visible light spectra and other partial spectra, infrared and other regions spectra cannot cause the photovoltaic effect, and partial energy is transmitted from the solar cell, and partial energy is conducted to the cell structure in a phonon form, so that the temperature of the photovoltaic cell is increased, and the performance of the photovoltaic cell is restricted. Thermoelectric power generation is a technology capable of directly converting heat energy into electric energy by utilizing the heat energy, and when temperature difference exists between two ends of a thermoelectric arm, a potential difference, namely a seebeck effect, is generated; with current generation in the pass case. The photovoltaic cell is coupled with the thermoelectric module, so that the waste heat generated by the photovoltaic cell can be utilized, and the secondary utilization of energy is realized. For a photovoltaic thermoelectric coupling system, the photoelectric conversion efficiency of a photovoltaic cell decreases with the rise of the temperature of a device, while the power generation of a thermoelectric module requires a higher temperature difference, and the inverse relationship between the photovoltaic cell and the thermoelectric module caused by the temperature change is an important factor influencing the system performance. Therefore, how to enhance the heat transfer of the photovoltaic cell to the thermoelectric module and ensure that the thermoelectric device has a large temperature difference is a key issue for improving the overall performance of the coupling system.

Disclosure of Invention

In order to improve the utilization of waste heat in the power generation process of a photovoltaic cell, reduce the heat loss caused by heat accumulation in a photovoltaic thermoelectric coupling device and improve the overall performance of the photovoltaic thermoelectric integrated device, the invention mainly aims to provide the photovoltaic thermoelectric integrated device with voltage matching.

The photovoltaic thermoelectric integrated device can keep low heat collection near the photovoltaic cell, reduce the heat loss of the photoelectric conversion efficiency of the photovoltaic cell, prolong the service life of the photovoltaic cell, efficiently transmit waste heat to the hot end of the thermoelectric cell, convert the waste heat into electric energy, has the characteristics of high light utilization rate, strong energy conversion capability and the like, and has low preparation process cost.

The invention further aims to provide a preparation method of the photovoltaic thermoelectric integrated device with voltage matching.

The purpose of the invention is realized by the following technical scheme:

a photovoltaic thermoelectric integrated device with voltage matching has the following structure from top to bottom: the solar cell comprises a photovoltaic cell, a conductive connecting layer, a thermoelectric cooler, a heat-conducting connecting layer and a thermoelectric cell;

one side of the conductive connecting layer is adhered to the back electrode surface of the photovoltaic cell, the other side of the conductive connecting layer is adhered to the cold end of the thermoelectric cooler, and the hot end of the thermoelectric cooler is fixedly adhered to the hot end of the thermoelectric cell through the conductive connecting layer.

Preferably, an external lead of the thermoelectric cooler is connected with a back electrode of the photovoltaic cell through a conductive connecting layer, so that the thermoelectric cooler and the photovoltaic cell are connected in series; the photovoltaic cell-thermoelectric cooler is connected in parallel with the thermoelectric cell device.

Preferably, the thermoelectric cooler is internally connected with the P-type thermoelectric arm pair and the N-type thermoelectric arm pair through copper foils to form a P-N-P-N thermoelectric arm series circuit, and the thermoelectric cell is internally connected with the P-type thermoelectric arm pair and the N-type thermoelectric arm pair through copper foils to form a P-N-P-N thermoelectric arm series circuit.

The junction of the thermoelectric cell and the thermoelectric cooler is a hot end, and the cold end of the thermoelectric cell is externally connected with a heat sink system, so that the heat dissipation of the cold end is enhanced, and the thermoelectric capacity of the thermoelectric cell is increased. The photovoltaic cell is connected with the thermoelectric cooler electrode in series through a lead, and the current generated by the photovoltaic cell supplies power to the thermoelectric cooling device, so that the heat generated by the photovoltaic cell in the photovoltaic power generation process is transported to the hot end of the thermoelectric cell. The photovoltaic cell and the thermoelectric cell adopt a parallel connection method, so that the voltage matching of the photovoltaic cell and the thermoelectric cell is ensured, and electric energy is better output outwards.

Preferably, the conductive connecting layer is connected with a back electrode of the photovoltaic cell and a cold end of the thermoelectric cooler through conductive silver paste, so that the negative electrode is led out more conveniently and is connected with a back device through a lead.

Preferably, the photovoltaic cell can be a single junction cell or a multi-junction cell, and the photovoltaic cell is a silicon-based thin film solar cell or a gallium arsenide thin film solar cell.

Preferably, the thermoelectric cooler is a thermocouple packaging device.

Preferably, the thermoelectric cell is a thermocouple-packaged device, and the material of the thermoelectric cell is bismuth antimonide more preferably.

Preferably, the conductive connection layer is made of at least one of a metal thin film, a semiconductor nano conductive thin film and a graphene two-dimensional thin film, and more preferably, is made of at least one of gold, silver, copper, chromium and nickel.

Preferably, the material of the heat-conducting connecting layer is at least one of silicone grease, silica gel, a phase-change material, a phase-change metal adhesive heat dissipation gasket and heat-conducting adhesive; the heat conductivity coefficient range of the heat-conducting connecting layer material is 0.1-50 W.m^-1·K^-1。

The preparation method of the photovoltaic thermoelectric integrated device with the voltage matching function comprises the following steps:

(1) bonding and fixing the back electrode surface of the photovoltaic cell and the conductive connecting layer by silver paste, and integrating the thermoelectric cooler on the conductive connecting layer by the silver paste;

(2) coating a heat-conducting connecting layer on the thermoelectric cooler, and integrating the thermoelectric cell at the hot end of the thermoelectric cooler through the heat-conducting connecting layer;

(3) connecting the negative electrode-conductive connecting layer of the photovoltaic cell with the thermoelectric cooler through a lead, connecting the photovoltaic cell with the thermoelectric cooler in series, and connecting the thermoelectric cell with the photovoltaic cell-thermoelectric cooler in parallel to form a voltage-matched parallel circuit;

(4) and packaging the solar cell into a photovoltaic and thermoelectric integrated cell.

Preferably, the electrically conductive connection layer in step (1) and the thermally conductive connection layer in step (2) are respectively located on both sides of the thermoelectric cooler.

Preferably, the encapsulating material in the step (4) is ethylene-vinyl acetate copolymer (EVA).

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention integrates the thermoelectric device and the thermoelectric cell on the back of the photovoltaic cell piece, and can utilize the waste heat generated in the photovoltaic power generation process to improve the energy conversion efficiency of the photovoltaic thermoelectric integrated device.

(2) The heat conducted by the thermoelectric cooler is gathered at the hot end of the thermoelectric cell, so that the temperature difference at two sides of the thermoelectric cell can be improved, the thermoelectric conversion performance of the thermoelectric cell is improved, and the energy conversion efficiency of the whole integrated device is increased finally.

(3) The solar cell module adopts a series structure of the photovoltaic cell and the thermoelectric cooler, the photovoltaic cell generates electricity to self-power the thermoelectric cooler, and the heat accumulated at the bottom of the photovoltaic cell due to integration is conducted to the lower part of the thermoelectric cooler, so that the photovoltaic cell can be effectively cooled, and the working and using time of a solar cell piece is prolonged.

Drawings

Fig. 1 is a schematic structural diagram of a photovoltaic thermoelectric integrated device of the present invention, wherein a solar cell 1, a conductive connection layer 2, a thermoelectric cooler 3, a heat conductive connection layer 4, a thermoelectric cell 5, an insulating ceramic package housing 6, an N-type thermoelectric arm 7, a P-type thermoelectric arm 8, and a copper foil 9.

Fig. 2 is a schematic circuit diagram of the photovoltaic-thermoelectric integrated device of the present invention, wherein the terminal 10 is shown.

Fig. 3 is a graph showing the operating temperature distribution of the photovoltaic-thermoelectric integrated device in accordance with example 1 of the present invention, wherein the temperature unit is ℃.

Fig. 4 is an I-V characteristic curve of a solar cell in the integrated photovoltaic thermoelectric device according to example 1 of the present invention.

Fig. 5 shows the structural operating temperature distribution of the conventional photovoltaic thermoelectric integrated device, wherein the temperature unit is ℃.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

Those who do not specify specific conditions in the examples of the present invention follow conventional conditions or conditions recommended by the manufacturer. The raw materials, reagents and the like which are not indicated for manufacturers are all conventional products which can be obtained by commercial purchase.

Referring to fig. 1, the photovoltaic thermoelectric integrated cell device of the invention comprises a solar cell (1), an electrically conductive connection layer (2), a thermoelectric cooler (3), a thermally conductive connection layer (4) and a thermoelectric cell (5). The thermoelectric cooler (3) and the thermoelectric cell (5) are both thermocouples in main structures, and comprise an insulating ceramic packaging shell (6), an N-type thermoelectric arm (7), a P-type thermoelectric arm (8) and a copper foil (9), wherein the N-type thermoelectric arm (7) and the P-type thermoelectric arm (8) are connected through the copper foil to form a series circuit. The thermoelectric couple of the thermoelectric cooler is powered by the solar cell, plays a role in transferring heat to cool the solar cell, is used as the thermoelectric couple of the thermoelectric cell to collect the waste heat of the device to generate electricity, and improves the energy conversion efficiency of the whole device.

Referring to fig. 2, the back electrode surface of the solar cell and the cold side of the thermoelectric cooler are fixed by conductive adhesive, and the lead of the thermoelectric cooler is connected with the conductive connection layer to form a series structure. The solar cell/thermoelectric cooler coupling structure and the thermoelectric cell device adopt a parallel connection structure, and the voltage matching of the solar cell/thermoelectric cooler coupling structure and the thermoelectric cell device is ensured. The hot end of the thermoelectric cooler and the hot end of the thermoelectric cell device are fixed by heat-conducting glue, so that good contact is ensured, and heat energy transfer is promoted. The cold end of the thermoelectric cell is connected with a heat sink system to promote the heat dissipation of the cold end of the thermoelectric cell. The whole photovoltaic/thermoelectric integrated system is connected with an external circuit through a terminal (10) to realize the function of supplying power to the external circuit.

Example 1

Gallium arsenide triple junction solar cells and bismuth antimonide thermoelectric cells are selected. And connecting the photovoltaic cell with the conductive connecting layer by silver paste coating, wherein the conductive layer is a copper-aluminum alloy film. And after the film is solidified at normal temperature, coating silver paste on the other side of the film, and connecting the film with a thermoelectric cooler. Coating a heat-conducting connecting layer material under the thermoelectric cooler, wherein the heat-conducting connecting layer material has a heat conductivity coefficient of 6 W.m^-1·K^-1The thermoelectric battery piece is integrated at the other end of the thermoelectric cooler; the connecting lead is connected with the thermoelectric cooler in series from the electrode connecting lead of the photovoltaic cell and forms a parallel circuit with the lowermost thermoelectric cell; the whole photovoltaic thermoelectric integrated battery is packaged by EVA, and the structure and the circuit connection are shown in figures 1-2.

The distribution of the operating temperature of the photovoltaic thermoelectric integrated device of the present embodiment is shown in fig. 3. In the photovoltaic-thermoelectric cooler-thermoelectric cell integrated device of the present embodiment, the I-V photoelectric performance curve of the solar cell device is shown in fig. 4, at this time, the operating temperature of the photovoltaic device in the integrated device is 29 ℃, the photoelectric conversion efficiency is 25.26%, and the energy conversion power density of the thermoelectric device portion is 5.11W/m²And finally, the output energy conversion efficiency of the whole integrated device is 25.77%.

Referring to fig. 5, when a thermoelectric cooler is not added (a traditional photovoltaic thermoelectric integrated device), the back electrode of the photovoltaic cell is connected with a conductive connecting layer by silver paste coating, and the conductive layer is selected from a copper-aluminum alloy film. After curing at normal temperature, coating the other side of the film with a heat conductivity coefficient of 6 W.m^-1·K^-1The thermal conductive silicone grease integrates the thermoelectric cell piece at the lower side of the conductive film layer. The cell temperature of the photovoltaic-temperature difference integrated device during steady-state operation of the solar cell is 32 ℃, the photoelectric conversion efficiency of the solar cell is 24.57 percent, and the power density of the thermoelectric device part is 3.85W/m²And finally, the energy conversion efficiency of the integral integrated device is 24.95%.

Example 2

Monocrystalline silicon solar cells and bismuth antimonide thermoelectric cells are selected. And connecting the photovoltaic cell with a conductive connecting layer by silver paste smearing, wherein the conductive connecting layer is made of copper foil. And after the copper foil is solidified at normal temperature, coating silver paste on the other side of the copper foil, and connecting the copper foil with a thermoelectric cooler. Coating a heat-conducting connecting layer material under the thermoelectric cooler, wherein the heat-conducting connecting layer material is selected to have a heat conductivity coefficient of 1.0 W.m^-1·K^-1The thermoelectric battery piece is integrated at the other end of the thermoelectric cooler; the photovoltaic cell electrode connecting wire is connected with the thermoelectric cooler in series and forms a parallel circuit with the lowermost thermoelectric cell; the whole photovoltaic thermoelectric integrated battery is packaged by EVA, and the structure and the circuit connection are shown in figures 1-2. The photoelectric conversion efficiency of the solar cell of the photovoltaic-temperature difference integrated device is 23.87%, and the power density of the thermoelectric device part is 4.11W/m²And the energy conversion efficiency of the final integral device is 24.28%.

Example 3

The solar cell is a polysilicon solar cell and a bismuth antimonide thermoelectric cell. And connecting the photovoltaic cell with a conductive connecting layer by silver paste coating, wherein the conductive layer is made of aluminum foil. And after the copper foil is solidified at normal temperature, coating silver paste on the other side of the copper foil, and connecting the copper foil with a thermoelectric cooler. Coating a heat-conducting connecting layer material under the thermoelectric cooler, wherein the heat-conducting connecting layer material has a heat conductivity coefficient of 4 W.m^-1·K^-1The thermoelectric battery piece is integrated at the other end of the thermoelectric cooler; the connecting lead is connected with the thermoelectric cooler in series from the electrode connecting lead of the photovoltaic cell and forms a parallel circuit with the lowermost thermoelectric cell; the whole photovoltaic thermoelectric integrated battery is packaged by EVA, and the structure and the circuit connection are shown in figures 1-2. The photoelectric conversion efficiency of the solar cell of the photovoltaic-temperature difference integrated device is 21.14%, and the power density of the thermoelectric device part is 4.24W/m²And the energy conversion efficiency of the final integral device is 21.56%.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.