Hot-spot-resistant photovoltaic cell, preparation method thereof and photovoltaic module

Abstract

The invention provides a hot spot resistant photovoltaic cell piece and a preparation method thereof, and a photovoltaic module, the hot spot resistant photovoltaic cell piece comprises a cell module, a heat conduction insulating layer and a thermistor layer, the cell module comprises a cell piece, a positive electrode grid and a negative electrode grid, and the positive electrode grid and the negative electrode grid are both arranged on a first side surface of the cell piece; the positive grid comprises a positive main grid and a positive auxiliary grid, the negative grid comprises a negative main grid and a negative auxiliary grid, the heat-conducting insulating layer is arranged on the first side face of the battery piece, the heat-conducting insulating layer is used for covering the positive auxiliary grid and the negative auxiliary grid, the heat-conducting insulating layer is provided with a window, and the window corresponds to at least one grid group; and the thermistor layer is a negative temperature coefficient thermistor layer and is arranged on one side, far away from the battery piece, of the heat-conducting insulating layer. The hot spot-resistant photovoltaic battery piece can effectively inhibit the hot spot phenomenon, the performance and reliability of the battery piece are improved, the fire risk is reduced, and the service life of the battery piece is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular, to a thermal-spot-resistant photovoltaic cell, a preparation method thereof, and a photovoltaic module. Background Art

[0002] Photovoltaic modules usually connect cells in series, resulting in a hot-spot phenomenon when a part is shaded or an individual cell fails, seriously affecting the power of the module and even leading to module damage or a fire risk. In related technologies, the solution to the hot spot of photovoltaic cells is to use a bypass diode to alleviate it, but this method is difficult to achieve hot-spot resistance at the cell level, and there are still problems of large power attenuation and high hot-spot temperature when facing serious local shading. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the related technologies to some extent.

[0004] To this end, an embodiment of the present invention provides a thermal-spot-resistant photovoltaic cell, a preparation method thereof, and a photovoltaic module. The thermal-spot-resistant photovoltaic cell can effectively inhibit the hot-spot phenomenon, improve the performance and reliability of the cell, reduce the fire risk, and extend the service life of the cell.

[0005] The thermal-spot-resistant photovoltaic cell according to an embodiment of the present invention includes:

[0006] a cell assembly, the cell assembly including a cell, a positive grid, and a negative grid. The positive grid and the negative grid are both provided on a first side of the cell. The positive grid includes a positive main grid and a positive sub-grid, and the negative grid includes a negative main grid and a negative sub-grid. The positive main grid and the negative main grid are alternately arranged at intervals along the length direction of the cell in turn, and the extending directions of the positive main grid and the negative main grid are both orthogonal to the length direction of the cell.

[0007] The positive sub-grid is connected to the positive main grid and is arranged at intervals along the extending direction of the positive main grid. The negative sub-grid is connected to the negative main grid and is arranged at intervals along the extending direction of the negative main grid. Between two adjacent positive grids and negative grids, the positive sub-grid and the negative sub-grid are alternately arranged at intervals along the width direction of the cell in turn, and every two adjacent positive sub-grids and negative sub-grids form a pole grid group.

[0008] a thermally conductive insulating layer, the thermally conductive insulating layer being provided on the first side of the cell, and the thermally conductive insulating layer being used to cover the positive sub-grid and the negative sub-grid. The thermally conductive insulating layer is provided with a window, and the window corresponds to at least one of the pole grid groups.

[0009] A thermistor layer, the thermistor layer being a negative temperature coefficient thermistor layer, and the thermistor layer being provided on a side of the thermally conductive insulating layer away from the cell.

[0010] In the anti - hot - spot photovoltaic cell of the embodiment of the present invention, the negative temperature coefficient thermistor layer can monitor the temperature of the cell in real time and automatically adjust the circuit state when the temperature rises abnormally, effectively suppressing the hot - spot phenomenon. When the cell is shaded and the temperature of the hot - spot rises, the resistivity of the thermistor layer gradually decreases, and finally the purpose of short - circuiting the locally shaded cell is achieved, realizing the anti - hot - spot ability at the cell level, thereby prolonging the service life of the cell.

[0011] In some embodiments, there are multiple windows, and the multiple windows are arranged at intervals along the width direction of the cell.

[0012] In some embodiments, there are also multiple window groups, the multiple window groups are arranged at intervals along the length direction of the cell, and each window group includes multiple windows.

[0013] In some embodiments, among two adjacent positive main grids and negative main grids, in the length direction of the cell, an insulating region is defined between the positive main grid and the negative main grid, and the thermally conductive insulating layer is placed in the insulating region.

[0014] In some embodiments, in a plane orthogonal to the length direction and the width direction of the cell, the projected area of the thermistor layer is less than or equal to the projected area of the thermally conductive insulating layer.

[0015] A method for manufacturing the anti - hot - spot photovoltaic cell of the embodiment of the present invention includes the following steps:

[0016] Lay a positive grid and a negative grid on the same side of the cell, and the positive main grid in the positive grid and the negative main grid in the negative grid are arranged alternately at intervals.

[0017] Arrange the positive sub - grids and the negative sub - grids in the two adjacent positive grids and negative grids alternately at intervals.

[0018] Lay a thermally conductive insulating layer on the side piece of the cell on which the positive grid and the negative grid are laid, so that the thermally conductive insulating layer covers the position area where the positive sub - grids and the negative sub - grids are arranged, and windows are opened on the thermally conductive insulating layer. The adjacent positive sub - grids and negative sub - grids form a grid group, and at least part of the grid group is exposed at the windows.

[0019] Lay a thermistor layer on the thermally conductive insulating layer, and the thermistor layer is a negative temperature coefficient thermistor layer.

[0020] In some embodiments, the thermally conductive insulating layer is laid using at least one of printing technology, coating technology, and thermal processing technology.

[0021] In some embodiments, the thermistor layer is prepared by mixing negative temperature coefficient thermistor particles with a binder to form a negative temperature coefficient thermistor paste, and the edge of the paste laying does not exceed the edge of the thermally conductive insulating layer. After the paste is laid, the paste is sintered.

[0022] The anti - hot - spot photovoltaic cell of the embodiment of the present invention is made by using the preparation method of the anti - hot - spot photovoltaic cell according to any one of the above - mentioned embodiments.

[0023] The photovoltaic module of the embodiment of the present invention includes the anti - hot - spot photovoltaic cell according to any one of the above - mentioned embodiments. Description of the Drawings

[0024] Figure 1 is a schematic structural diagram of the anti - hot - spot photovoltaic cell of the embodiment of the present invention.

[0025] Figure 2 is Figure 1 an enlarged schematic diagram of A shown in

[0026] Figure 3 is a partial structural schematic diagram of the anti - hot - spot photovoltaic cell of the embodiment of the present invention.

[0027] Reference Signs:

[0028] 1. Battery assembly, 11. Battery cell, 12. Positive electrode grid, 121. Positive main grid, 122. Positive sub - grid, 13. Negative electrode grid, 131. Negative main grid, 132. Negative sub - grid,

[0029] 2. Thermally conductive insulating layer, 21. Window,

[0030] 3. Thermistor layer. Detailed Embodiments

[0031] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] As shown in the figure, the anti - hot - spot photovoltaic cell of the embodiment of the present invention includes: a battery assembly 1, a thermally conductive insulating layer 2, and a thermistor layer 3.

[0033] The battery module 1 includes battery cells 11, a positive grid 12, and a negative grid 13. The positive grid 12 and the negative grid 13 are both provided on the first side of the battery cell 11. The positive grid 12 includes a positive main grid 121 and positive sub-grids 122, and the negative grid 13 includes a negative main grid 131 and negative sub-grids 132. The positive main grid 121 and the negative main grid 131 are arranged alternately and at intervals in sequence along the length direction of the battery cell 11 (such as Figure 1 the left-right direction in

[0034] ). Moreover, the extending directions of the positive main grid 121 and the negative main grid 131 are both orthogonal to the length direction of the battery cell 11. The positive sub-grids 122 are connected to the positive main grid 121 and are arranged at intervals along the extending direction of the positive main grid 121. The negative sub-grids 132 are connected to the negative main grid 131 and are arranged at intervals along the extending direction of the negative main grid 131. Between two adjacent positive grids 12 and negative grids 13, the positive sub-grids 122 and the negative sub-grids 132 are arranged alternately and at intervals in sequence along the width direction of the battery cell 11, and every two adjacent positive sub-grids 122 and negative sub-grids 132 form a grid group.

[0035] Specifically, as shown in the figure, the positive grid 12 and the negative grid 13 are provided on the same side of the battery cell 11. That is, according to the different structures of the battery cell 11, one side of the battery cell 11 can be appropriately selected to install the positive grid 12 and the negative grid 13. For example, the positive grid 12 and the negative grid 13 are installed on the backlight side of the battery cell 11 to reduce the shielding of the battery cell 11 and ensure the power generation efficiency of the battery cell 11. The positive grid 12 and the negative grid 13 are connected to the battery cell 11 by welding, and multiple positive sub-grids 122 and multiple negative sub-grids 132 correspond one by one and form a parallel connection circuit.

[0036] It can be understood that the heat-conducting insulating layer 2 is provided on the same side as the positive grid 12, and the heat-conducting insulating layer 2 is used to be laid in the area where the positive sub-grids 122 and the negative sub-grids 132 are arranged to provide insulation protection. The heat-conducting insulating layer 2 can not only maintain the insulation between battery cells 11 but also transfer the heat of the battery cell 11 to the outside, reduce the working temperature of the battery cell 11, and reduce the hot spot phenomenon. The thermistor layer 3 is a negative temperature coefficient thermistor layer 3, and the thermistor layer 3 is laid on the heat-conducting insulating layer 2. Among them, since at least one grid group is exposed at the window 21 of the heat-conducting insulating layer 2, thus, the resistance value of the thermistor layer 3 can be changed according to the temperature change on the positive sub-grids 122 and the negative sub-grids 132.

[0037] That is to say, when the solar cell 11 operates normally, its temperature is relatively low, and the resistivity of the thermistor area is large, making the positive secondary grid 122 and the negative secondary grid 132 in an open - circuit state. When the solar cell 11 is shaded and the temperature rises to form a hot spot, the resistivity of the thermistor area gradually decreases, and finally the local - shaded solar cell 11 is short - circuited, achieving the anti - hot - spot ability at the level of the solar cell 11.

[0038] In other words, the anti - hot - spot photovoltaic cell of the embodiment of the present invention utilizes the negative - temperature - coefficient thermistor layer 3 to be able to monitor the temperature of the solar cell 11 in real time, and automatically adjusts the circuit state when the temperature rises abnormally, effectively suppressing the hot - spot phenomenon. The resistivity of the thermistor layer 3 gradually decreases as the temperature of the solar cell 11 rises, and finally the main grids of the locally - shaded solar cell 11 are short - circuited, with the anti - hot - spot ability at the level of the solar cell 11, thereby prolonging the service life of the solar cell 11.

[0039] In some embodiments, there are multiple windows 21, and the multiple windows 21 are arranged at intervals along the width direction of the solar cell 11 (such as Figure 1 the front - to - back direction in the figure). Specifically, as shown in the figure, the multiple windows 21 are arranged at intervals in sequence along the front - to - back direction. Optionally, in one window 21, one grid group can correspond; or, in one window 21, multiple grid groups can correspond.

[0040] That is to say, during use, as the temperature of the solar cell 11 gradually rises, the resistivity of the corresponding thermistor layer 3 gradually decreases, so that the grid groups exposed in the window 21 can be short - circuited. And having multiple grid groups corresponding to one window 21 can ensure the short - circuit of the grid groups as much as possible.

[0041] In some embodiments, there are also multiple groups of windows 21, and the multiple groups of windows 21 are arranged at intervals along the length direction of the solar cell 11, and each group of windows 21 includes multiple windows 21. It can be understood that, as shown in the figure, one group of windows 21 includes multiple windows 21 arranged at intervals in sequence along the front - to - back direction, and the multiple groups of windows 21

[0042] In some embodiments, between two adjacent positive main grids 121 and negative main grids 131, in the length direction of the solar cell 11, an insulating area is defined between the positive main grid 121 and the negative main grid 131, and the thermally conductive insulating layer 2 is placed in the insulating area.

[0043] In some embodiments, in a plane orthogonal to the length direction and the width direction of the solar cell 11, the projected area of the thermistor layer 3 is less than or equal to the projected area of the thermally conductive insulating layer 2.

[0044] The preparation method of the anti - hot - spot photovoltaic cell of the embodiment of the present invention includes the following steps:

[0045] The positive grid 12 and the negative grid 13 are laid on the same side of the battery cell 11, and the positive main grid 121 in the positive grid 12 and the negative main grid 131 in the negative grid 13 are arranged alternately at intervals in sequence;

[0046] The positive sub-grid 122 and the negative sub-grid 132 in two adjacent positive grids 12 and negative grids 13 are arranged alternately at intervals;

[0047] A heat-conducting insulating layer 2 is laid on the side piece of the battery cell 11 where the positive grid 12 and the negative grid 13 are laid, so that the heat-conducting insulating layer 2 covers the position area where the positive sub-grid 122 and the negative sub-grid 132 are arranged, and a window 21 is opened on the heat-conducting insulating layer 2. The adjacent positive sub-grid 122 and negative sub-grid 132 form a grid group, and at least part of the grid group is exposed at the window 21;

[0048] A thermistor layer 3 is laid on the heat-conducting insulating layer 2, and the thermistor layer 3 is a negative temperature coefficient thermistor layer 3.

[0049] In some embodiments, the heat-conducting insulating layer 2 is laid by at least one of printing technology, coating technology and hot processing technology.

[0050] In some embodiments, the thermistor layer 3 is prepared by mixing negative temperature coefficient thermistor particles and a binder into a negative temperature coefficient thermistor paste, and the edge of the paste laying does not exceed the edge of the heat-conducting insulating layer 2. After the paste is laid, the paste is sintered.

[0051] The anti-thermal-spot photovoltaic cell of the embodiment of the present invention is made by using the preparation method of the anti-thermal-spot photovoltaic cell in any one of the above embodiments.

[0052] The photovoltaic module of the embodiment of the present invention includes the anti-thermal-spot photovoltaic cell in any one of the above embodiments.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0055] In the present invention, unless otherwise clearly defined and limited, terms such as "mounted", "connected", "coupled", "fixed", etc. should be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0057] In the present invention, terms such as "an embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0058] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A hot spot resistant photovoltaic cell, characterized in that: include: A battery assembly, the battery assembly comprising a battery cell, a positive electrode grid and a negative electrode grid, the positive electrode grid and the negative electrode grid are both arranged on a first side of the battery cell, the positive electrode grid comprises a positive electrode main grid and a positive electrode sub-grid, the negative electrode grid comprises a negative electrode main grid and a negative electrode sub-grid, the positive electrode main grid and the negative electrode main grid are alternately arranged in sequence along the length direction of the battery cell, and the extension direction of the positive electrode main grid and the extension direction of the negative electrode main grid are both orthogonal to the length direction of the battery cell, The positive electrode sub-grid is connected to the positive electrode main grid and is arranged at intervals along the extension direction of the positive electrode main grid, the negative electrode sub-grid is connected to the negative electrode main grid and is arranged at intervals along the extension direction of the negative electrode main grid, between two adjacent positive electrode grids and negative electrode grids, the positive electrode sub-grid and the negative electrode sub-grid are alternately arranged in sequence along the width direction of the battery cell, and every two adjacent positive electrode sub-grids and negative electrode sub-grids form a grid group; A heat-conducting insulating layer, the heat-conducting insulating layer is disposed on the first side of the battery cell, and the heat-conducting insulating layer is used to cover the positive electrode sub-grid and the negative electrode sub-grid, and the heat-conducting insulating layer is provided with a window, and the window corresponds to at least one of the grid groups; The thermistor layer is a negative temperature coefficient thermistor layer, and the thermistor layer is arranged on a side of the thermally conductive insulating layer away from the battery cell.

2. The anti-hot spot photovoltaic cell according to claim 1, characterized in that: There are a plurality of windows, and the plurality of windows are arranged at intervals along the width direction of the battery sheet.

3. The hot spot resistant photovoltaic cell according to claim 2, characterized in that: It also includes a plurality of window groups, which are arranged at intervals along the length direction of the battery sheet, and each of the window groups includes a plurality of the windows.

4. The hot spot resistant photovoltaic cell according to claim 3, characterized in that: In two adjacent positive electrode main grids and negative electrode main grids, an insulating region is defined between the positive electrode main grid and the negative electrode main grid in the length direction of the battery cell, and the thermally conductive insulating layer is disposed in the insulating region.

5. The hot spot resistant photovoltaic cell according to claim 4, characterized in that: In a plane orthogonal to the length direction of the battery cell and the width direction of the battery cell, a projected area of ​​the thermistor layer is less than or equal to a projected area of ​​the thermally conductive insulating layer.

6. A method for preparing a hot spot resistant photovoltaic cell, characterized in that: The following steps are involved: The positive electrode grid and the negative electrode grid are laid on the same side of the battery sheet, and the positive electrode main grid in the positive electrode grid and the negative electrode main grid in the negative electrode grid are arranged alternately in sequence; The positive electrode sub-grids and the negative electrode sub-grids in two adjacent positive electrode grids and negative electrode grids are arranged alternately; Laying a heat-conducting insulating layer on the side of the battery sheet where the positive and negative grids are laid, so that the heat-conducting insulating layer covers the position area where the positive and negative sub-grids are arranged, and a window is opened on the heat-conducting insulating layer, and the adjacent positive and negative sub-grids form a grid group, and at least part of the grid group is exposed at the window; A thermistor layer is laid on the heat-conducting insulating layer, wherein the thermistor layer is a negative temperature coefficient thermistor layer.

7. The method for preparing the hot spot resistant photovoltaic cell according to claim 6, characterized in that: The thermally conductive insulating layer is laid using at least one of a printing technique, a coating technique and a thermal processing technique.

8. The method for preparing a hot spot resistant photovoltaic cell according to claim 6, characterized in that: The thermistor layer is prepared by mixing negative temperature coefficient thermistor particles with a binder to form a negative temperature coefficient thermistor slurry, and the slurry laying edge does not exceed the edge of the thermal conductive insulation layer. After the slurry is laid, the slurry is sintered.

9. A hot spot resistant photovoltaic cell, characterized in that: The anti-hot-spot photovoltaic cell sheet is manufactured by the method for preparing an anti-hot-spot photovoltaic cell sheet according to any one of claims 6 to 8.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises the anti-hot-spot photovoltaic cell sheet according to any one of claims 1 to 5 and 9.

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