Photovoltaic device and photovoltaic module

Abstract

The photovoltaic device comprises a battery piece and a temperature control film arranged on a first surface of the battery piece, the first surface of the battery piece comprises a positive electrode and a negative electrode, and the temperature control film is in contact with the positive electrode and the negative electrode of the battery piece; the resistivity of the temperature control film is negatively correlated with the temperature; the temperature control film has an insulation state and a conductive state, when the temperature of the first area of the battery piece is within the normal working temperature range of the battery piece, a second area, corresponding to the first area, on the temperature control film is in the insulation state, when the temperature of the first area reaches the first temperature, the second area is in the conductive state, and the second area enables the first area to be short-circuited. When hot spots occur, the loss of the generating capacity of the photovoltaic module adopting the photovoltaic device is small, so that the generating efficiency of the photovoltaic module is greatly improved when the photovoltaic module is shielded.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a photovoltaic device and a photovoltaic assembly. Background Art

[0002] Photovoltaic modules are prone to shadowing when used outdoors. When a cell in a battery string is partially shaded, a reverse bias voltage will be generated on the cell. Due to the existence of the reverse bias voltage, a reverse leakage current will be generated in the weak area of ​​the cell. The greater the leakage current, the more heat will be generated, which will cause the local temperature of the cell to rise rapidly, resulting in a hot spot effect.

[0003] At present, the battery string group in the photovoltaic module includes multiple battery strings, and the battery string includes multiple battery cells connected in series. In order to avoid the hot spot effect, a bypass diode is usually connected in parallel at both ends of each battery string. However, when the battery cells in a battery string have a hot spot effect, the bypass diode connected in parallel with the battery string is turned on, bypassing the entire battery string, resulting in a significant drop in the power generation of the photovoltaic module, thereby greatly reducing the power generation efficiency of the photovoltaic module. Utility Model Content

[0004] The utility model provides a photovoltaic device and a photovoltaic module, aiming at least to solve the technical problem in the prior art that the power generation efficiency of the photovoltaic module is greatly reduced when the hot spot effect occurs.

[0005] In a first aspect, an embodiment of the utility model provides a photovoltaic device, comprising a battery cell and a temperature control film disposed on a first surface of the battery cell, wherein the first surface of the battery cell comprises a positive electrode and a negative electrode, and the temperature control film is in contact with both the positive electrode and the negative electrode of the battery cell; the resistivity of the temperature control film is negatively correlated with the temperature;

[0006] The temperature control film has an insulating state and a conductive state. When the temperature of the first area of ​​the battery cell is within the normal operating temperature range of the battery cell, the second area on the temperature control film corresponding to the first area is in an insulating state. When the temperature of the first area reaches a first temperature, the second area is in a conductive state, and the second area short-circuits the first area, wherein the first temperature is greater than the maximum value of the normal operating temperature range.

[0007] Optionally, the temperature control film comprises a thermistor material. When the temperature of the first region is greater than or equal to a first temperature, the resistivity of the thermistor material at a position corresponding to the first region is less than a preset value, and the temperature control film at least short-circuits the first region.

[0008] The cell area corresponding to the domain.

[0009] Optionally, the first temperature is 106°C-140°C.

[0010] Optionally, the first temperature is 120°C-140°C, when the temperature of a certain area of ​​the temperature control film is 120°C, the resistivity of the thermistor material in this area is 5Ω·cm-300Ω·cm, and when the temperature of a certain area of ​​the temperature control film is 140°C, the resistivity of the thermistor material in this area is 0.1Ω·cm-100Ω·cm.

[0011] Optionally, when the temperature of the first region is greater than the first temperature, as the temperature of the first region continues to increase, the resistivity of the thermistor material at the first corresponding position gradually decreases.

[0012] Optionally, when the temperature of a certain area of ​​the temperature control film is 170° C.-200° C., the resistivity of the thermistor material in the area is less than 0.01Ω·cm.

[0013] Optionally, the thermistor material has an insulating state, and when the temperature is less than or equal to the maximum value of the normal working temperature range, the thermistor material is in the insulating state, and the temperature control film is in the insulating state.

[0014] Optionally, when the thermistor material is in an insulating state, the resistivity of the thermistor material is greater than 10 4 Ω·cm.

[0015] Optionally, the battery cell is a back contact battery cell.

[0016] Optionally, the positive and negative electrodes include positive electrode grid lines and negative electrode grid lines, and / or positive electrode connecting lines and negative electrode connecting lines.

[0017] Optionally, the positive electrode connecting wire and the negative electrode connecting wire are metal connecting wires.

[0018] Optionally, the photovoltaic device is a photovoltaic device, the temperature control film further comprises a film body, the surface of the film body close to the battery sheet has grid-shaped grooves, and the thermistor material is filled in the grooves.

[0019] Optionally, the thermistor material is formed by curing negative temperature coefficient conductive ink, and the negative temperature coefficient conductive ink includes a negative temperature coefficient filler.

[0020] Optionally, the temperature control film covers a battery string group including a plurality of the battery cells; or, the temperature control film includes a plurality of temperature control sub-membranes, and the plurality of temperature control sub-membranes respectively cover a plurality of the battery cells.

[0021] Optionally, the material of the adhesive film body is ethylene-vinyl acetate copolymer or polyolefin elastomer, the adhesive film body is pre-cured, and the pre-crosslinking degree of the adhesive film body is 10%-60%.

[0022] Optionally, the width of the groove is 5 micrometers to 500 micrometers, and the ratio of the width of the groove to the depth of the groove is 0.1-2.

[0023] Optionally, the positive and negative electrodes include a plurality of positive electrode grid lines and a plurality of negative electrode grid lines, and the temperature control film covers at least one adjacent positive electrode grid line and one adjacent negative electrode grid line.

[0024] Optionally, the positive electrode grid lines and the negative electrode grid lines are thin grid lines, and a plurality of the positive electrode grid lines and a plurality of the negative electrode grid lines are staggered in sequence along a first direction and arranged in a forked finger shape. Along the first direction, the plurality of the positive electrode grid lines and the plurality of the negative electrode grid lines have an overlapping area, and the temperature control film at least covers a portion of the overlapping area.

[0025] Optionally, the temperature control film covers ends of the plurality of positive electrode grid lines and the plurality of negative electrode grid lines.

[0026] Optionally, the positive and negative electrodes further include a positive busbar and a negative busbar, the positive busbar is connected to a plurality of the positive grid lines, and the negative busbar is connected to a plurality of the negative grid lines.

[0027] Optionally, the temperature control film is arranged between the positive electrode bus grid and the negative electrode bus grid.

[0028] Optionally, the temperature control membrane is a plurality of discontinuous sub-membranes, and each of the sub-membranes is located between adjacent positive electrode bus bars and negative electrode bus bars.

[0029] Optionally, the temperature control film is a single continuous film disposed on the first surface of the battery cell, and the temperature control film exposes the soldering pad position of the battery cell.

[0030] Optionally, the temperature control film is formed on the first surface of the battery cell by deposition.

[0031] In a second aspect, an embodiment of the utility model provides a photovoltaic assembly, comprising any photovoltaic device described above.

[0032] In the embodiment of the utility model, when the battery cell is partially blocked and a hot spot occurs in the first area, the temperature of the first area rises, and the temperature of the second area on the temperature control film that is in contact with the first area rises, the resistivity of the second area decreases, and the second area becomes conductive. When the temperature of the first area rises to the first temperature, the leakage current flows through the second area on the temperature control film instead of flowing through the inside of the partially blocked battery cell, that is, the first area on the partially blocked battery cell is bypassed, thereby avoiding damage to the battery cell caused by the continuous increase in the temperature of the first area on the battery cell.

[0033] Since only the temperature of the second area on the temperature control film that is in contact with the first area with increased temperature increases, and the temperatures of other areas do not increase, only the first area with increased temperature on the partially shielded battery cell will be bypassed without affecting other battery cells on the battery string where the shielded battery cell is located, so that the battery string can still generate electricity normally, and the loss of power generation of the photovoltaic module using the photovoltaic device is small, thereby greatly improving the power generation efficiency of the photovoltaic module when shielded and ensuring the power generation of the power station; in addition, through the setting of the temperature control film, the bypass diode is eliminated, avoiding the safety hazard caused by the failure of the bypass diode.

[0034] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of an exploded structure when the photovoltaic device provided in the first embodiment of the utility model is a photovoltaic laminate;

[0036] Figure 2 Schematic diagram of the circuit structure of an equivalent battery and an equivalent resistor;

[0037] Figure 3 The structure of the temperature control film provided in the first embodiment of the utility model is schematically shown. Figure 1 ;

[0038] Figure 4 The structure of the temperature control film provided in the first embodiment of the utility model is schematically shown. Figure 2 ;

[0039] Figure 5 A cross-sectional schematic diagram of a temperature control membrane provided in Embodiment 1 of the present utility model;

[0040] Figure 6 A schematic diagram of a battery cell in a single battery string being blocked in a battery string group;

[0041] Figure 7 A schematic diagram showing leakage current generated at a local location of a shielded cell;

[0042] Figure 8 for Figure 7 A partial enlarged schematic diagram of

[0043] Fig. 9 Schematic diagram of leakage current flowing through the thermistor material.

[0044] Fig.10 for Fig. 9 A partial enlarged schematic diagram of

[0045] Fig.11 When the photovoltaic device provided in the second embodiment of the utility model is a solar cell, a schematic diagram of an exploded structure of a photovoltaic assembly including the solar cell;

[0046] Fig.12 A schematic diagram of the structure of a photovoltaic device provided in the second embodiment of the present utility model when the photovoltaic device is a solar cell;

[0047] Fig.13 A schematic diagram of a partial structure of a photovoltaic device provided in the second embodiment of the present utility model when the photovoltaic device is a solar cell;

[0048] Fig.14 The photovoltaic device provided for the second embodiment of the utility model is a solar cell, which is a structural schematic diagram of shielding treatment during processing of the solar cell.

[0049] Reference numerals:

[0050] 1-glass cover, 2-upper packaging film, 3-battery string, 31-battery cell, 311-positive electrode grid line, 312-negative electrode grid line, 313-positive electrode bus bar, 314-negative electrode bus bar, 315-soldering pad, 4-temperature control film, 41-film body, 411-groove, 42-thermistor material, 43-sub-film, 5-lower packaging film, 6-back glass, 7-equivalent battery, 8-equivalent resistor, 9-shielding object. DETAILED DESCRIPTION

[0051] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0052] The back-contact cell sets both the P and N regions of the cell on the back of the cell, thus avoiding shading on the front of the cell, increasing the light-receiving area of ​​the cell, and greatly improving the efficiency of the cell. At the same time, since there are no grid lines and welding strips on the front of the back-contact cell, the appearance consistency of the photovoltaic module is greatly improved. When photovoltaic modules including back-contact cells are used outdoors, shadow shading is prone to occur. When shading occurs, reverse cutoff will occur in the shaded cell and reverse bias will be generated. The loading of reverse voltage will generate reverse leakage current between the P and N regions. The greater the leakage current, the more heat will be generated, which will cause the local temperature of the shaded cell to rise rapidly, resulting in a hot spot effect.

[0053] At present, in order to avoid the hot spot effect, a bypass diode is usually connected in parallel at both ends of each battery string. However, when the hot spot effect occurs in the cells in a battery string, the bypass diode connected in parallel with the battery string is turned on, bypassing the entire battery string, causing a significant drop in the power generation of the photovoltaic module, thereby greatly reducing the power generation efficiency of the photovoltaic module. In areas where shadows are frequent, it will cause a drop in the power generation of the power station; in addition, as an electrical component, the bypass diode has a certain probability of failure, posing a safety hazard.

[0054] In order to solve the above problems, the embodiments of the present utility model provide a photovoltaic device and a photovoltaic module.

[0055] First, refer to Figure 1 and Fig.12 The embodiment of the utility model discloses a photovoltaic device, including a battery cell 31 and a temperature control film 4 arranged on the first surface of the battery cell 31, the first surface of the battery cell 31 includes positive and negative electrodes, and the temperature control film 4 is in contact with both the positive and negative electrodes of the battery cell 31; the resistivity of the temperature control film 4 is negatively correlated with the temperature; the temperature control film 4 has an insulating state and a conductive state, when the temperature of the first area of ​​the battery cell 31 is within the normal operating temperature range of the battery cell 31, the second area on the temperature control film 4 corresponding to the first area is in an insulating state, when the temperature of the first area reaches the first temperature, the second area is in a conductive state, and the second area short-circuits the first area, wherein the first temperature is greater than the maximum value of the normal operating temperature range.

[0056] Specifically, the cell 31 is a back contact cell, such as an IBC (Interdigitated Back Contact) cell, which may be a heterojunction back contact cell, a topcon back contact cell, etc. In this case, the first surface is the backlight surface of the cell 31. Figure 1 In the first embodiment, when the photovoltaic device is a photovoltaic laminate, it also includes a glass cover plate 1, an upper packaging film 2, a lower packaging film 5 and a back glass 6 or a back plate. The glass cover plate 1, the upper packaging film 2, the battery string group 3, the temperature control film 4, the lower packaging film 5 and the back glass 6 or the back plate are stacked in sequence, and the temperature control film 4 is located between the battery string group 3 and the lower packaging film 5. The temperature control film 4 is a whole layer of film and is attached to the back of the battery string group 3. Alternatively, the temperature control film 4 is a plurality of segmented film layers, which at least cover the positive and negative electrodes of each battery cell. The glass cover plate 1, the upper packaging film 2, the battery string group 3, the temperature control film 4, the lower packaging film 5 and the back glass 6 are formed into a photovoltaic laminate through a lamination process.

[0057] Reference Fig.11 and Fig.12In the second embodiment, when the photovoltaic device is a cell 31, the temperature control film 4 is formed on the first surface of the cell 31 by deposition, and the deposition method is any one of magnetron sputtering, spin coating, evaporation, and PECVD. The cell 31 coated with the temperature control film 4 can be subjected to string welding and other processes to obtain a cell string. The cell string group 3 includes a plurality of such cell strings. The glass cover plate 1, the upper packaging film 2, the cell string group 3, the lower packaging film 5, and the back glass 6 are subjected to a lamination process to form a photovoltaic laminate.

[0058] The positive and negative electrodes include positive electrode grid lines and negative electrode grid lines, and / or positive electrode connecting lines and negative electrode connecting lines. The positive electrode connecting lines and negative electrode connecting lines are metal connecting lines, which include structures such as welding strips, connecting sheets, and electroplated connecting patterns. Both the positive electrode grid lines and the negative electrode grid lines may include main grids and fine grids. The positive electrode connecting lines and the negative electrode connecting lines may specifically be welding strips. The resistivity of the temperature control film 4 decreases as the temperature increases. When a hot spot occurs, the temperature of the hot spot area increases, and the temperature of the area on the temperature control film 4 that is in contact with the hot spot area increases, the resistivity of the temperature control film 4 in this area decreases, the temperature control film 4 is conductive, and the leakage current flows through the positive and negative electrodes on the battery cell from the position on the temperature control film 4 corresponding to the hot spot area.

[0059] The normal operating temperature range of the battery cell 31 can be -40℃-85℃, and at this time, the maximum value of the normal operating temperature range is 85℃. When the temperature of the first area is within the normal operating temperature range, the second area on the temperature control film 4 is in an insulating state, and the first area on the battery cell 31 works normally, and no leakage current is generated. The first temperature can be set according to actual needs, such as 106℃-140℃, preferably 120℃-130℃. When the temperature of the first area on the battery cell 31 is greater than or equal to the first temperature, the resistivity of the second area on the temperature control film 4 gradually decreases, and the second area is converted to a conductive state. At this time, the leakage current flows through the second area on the temperature control film 4, and the second area short-circuits the first area.

[0060] When a hot spot occurs, the cell will be damaged when the minimum temperature at which the cell is damaged due to a hot spot is reached. The first temperature is greater than the maximum value of the normal operating temperature range and less than the minimum temperature at which the cell is damaged due to a hot spot, so as to ensure that before the cell is damaged due to the hot spot, the second area on the temperature control film has short-circuited the first area where the hot spot occurs, thereby avoiding damage to the cell due to the continuous increase in the temperature of the first area on the cell.

[0061] When a photovoltaic module generates electricity under light, photogenerated electron-hole pairs are generated in the cell, the PN junction separates, the electrons flow into the N region, the holes flow into the P-type region, and are converged through the grid lines, welding strips, and bus bars and then transmitted through the cables. Light continues to irradiate the cell, and electrons and holes are continuously generated, thus forming a continuous current. When the surface of the cell is partially blocked, there is no photogenerated current in the blocked area, and the photogenerated current of the cell decreases. This area will be in a reverse biased state due to the structure of the PN junction. Since there are usually multiple cells in a photovoltaic module connected in series, the current of the remaining cells still has to flow through the blocked cell. Due to the reverse bias state of the blocked area, a reverse bias voltage will be generated, and the excess current will pass densely through the weak junction area on the cell, forming a leakage current, and the leakage current increases with the increase of the reverse bias voltage. Due to the consumption of leakage current, heat will be generated in the dense leakage area, causing the temperature of the area to rise and hot spots to occur.

[0062] In the embodiment of the utility model, the battery cell 31 is partially blocked. When a hot spot occurs in the first area, the temperature of the first area rises, and the temperature of the second area on the temperature control film 4 that is in contact with the first area rises, the resistivity of the second area decreases, and the second area is conductive. When the temperature of the first area rises to the first temperature, the leakage current flows through the second area on the temperature control film 4 instead of flowing through the partially blocked battery cell 31, that is, the first area on the partially blocked battery cell 31 is bypassed, thereby avoiding damage to the battery cell caused by the continuous increase in the temperature of the first area on the battery cell 31.

[0063] Since only the temperature of the second area on the temperature control film 4 that is in contact with the first area with increased temperature increases, and the temperatures of other areas do not increase, only the first area with increased temperature on the partially shielded cell 31 will be bypassed, without affecting other cells on the cell string where the shielded cell 31 is located, so that the cell string can still generate electricity normally, and the loss of power generation of the photovoltaic module using the photovoltaic device is small, thereby greatly improving the power generation efficiency of the photovoltaic module when shielded, and ensuring the power generation of the power station; in addition, since the temperature control film 4 is added to the photovoltaic module, the photovoltaic module will have no hot spot risk, and the bypass diode usually required for the photovoltaic module can be cancelled. By canceling the bypass diode, safety hazards caused by failure of the bypass diode are avoided.

[0064] In the prior art, a small bypass diode is also connected in parallel to each cell to bypass protect the single cell. However, the thickness of the bypass diode is usually more than 1 mm. Since the total thickness of the packaging film of the photovoltaic module is generally less than 1 mm, the bypass diode is prone to bulging on the single-glass module. In the double-glass module, the bypass diode position will lack the film, and the upper and lower layers of glass will directly contact the bypass diode, resulting in greater stress and easy glass shattering. In the embodiment of the utility model, the bypass diode connected in parallel to the single cell is eliminated by the provision of the temperature control film 4, thereby avoiding bulging of the single-glass module and glass shattering in the double-glass module caused by the provision of the bypass diode.

[0065] The temperature control film 4 includes a thermistor material 42. When the temperature of the first area is greater than or equal to the first temperature, the resistivity of the thermistor material 42 at the corresponding position of the first area is less than a preset value, and the temperature control film 4 at least short-circuits the battery cell area corresponding to the first area.

[0066] Specifically, when a hot spot occurs, the first area is a hot spot area. The thermistor material 42 has a critical temperature, which is consistent with the first temperature. When the temperature of the first area is greater than or equal to the first temperature, the resistivity of the thermistor material 42 is less than a preset value, and at this time, the leakage current flows through the thermistor material 42. In embodiment one, the temperature control film 4 includes a film body 41 and a thermistor material 42. The material of the film body 41 is an insulating material, and the thermistor material 42 is in an insulating state when the temperature is less than or equal to the maximum value of the normal operating temperature range of the battery cell. In embodiment two, the temperature control film 4 includes the thermistor material 42, but does not include the film body 41.

[0067] The resistivity of the thermistor material 42 is negatively correlated with temperature, and the resistivity of the thermistor material 42 decreases as the temperature increases. The resistivity of the thermistor material 42 rapidly decreases to an extremely low state within the rapid temperature drop interval, thereby approaching that of a metal conductor. The rapid temperature drop interval may be any temperature interval between a temperature that exceeds the normal working temperature of the photovoltaic module and a safe temperature at which the module is not damaged when a hot spot occurs. The lower limit of the rapid temperature drop interval may be 100°C, and the upper limit of the rapid temperature drop interval may be 170°C-200°C.

[0068] The preset value is set according to the actual situation. The preset value can ensure that when the resistivity of the thermistor material 42 is less than the preset value, the leakage current flows through the thermistor material 42 instead of flowing through the battery cell. For example, the preset value can be 250Ω·cm-300Ω·cm. When the first temperature is 120°C, the resistivity of the thermistor material 42 is 5Ω·cm-300Ω·cm. When the temperature is less than the first temperature, the resistivity of the thermistor material 42 is greater than or equal to 10 4 Ω·cm.

[0069] The thermistor material 42 has an insulating state. When the temperature is less than or equal to the maximum value of the normal working temperature range, the thermistor material 42 is in the insulating state, and the temperature control film 4 is in the insulating state.

[0070] Specifically, when the photovoltaic module is operating normally, the thermistor material 42 is in an insulating state. When the thermistor material 42 is in an insulating state, the conductivity of the thermistor material 42 is greater than 10 4 Ω·cm, preferably greater than 10 7 Ω·cm. When the temperature is 25°C, the conductivity of the thermistor material 42 is 5×10 8 Ω·cm-10×10 8 Ω·cm. When the temperature is 65°C, the conductivity of the thermistor material 42 is 3×10 7 Ω·cm-9×10 7 Ω·cm. In the embodiment of the utility model, through the above arrangement, when the photovoltaic module is working normally, the temperature control film will not affect the performance of the photovoltaic module.

[0071] The first temperature is 120°C-140°C. When the temperature of a certain area of ​​the temperature control film is 120°C, the resistivity of the thermistor material in the area is 5Ω·cm-300Ω·cm. When the temperature of a certain area of ​​the temperature control film is 140°C, the resistivity of the thermistor material in the area is 0.1Ω·cm-100Ω·cm. When the temperature of the first area is greater than the first temperature, as the temperature of the first area continues to increase, the resistivity of the thermistor material at the corresponding position of the first area gradually decreases. When the temperature of a certain area of ​​the temperature control film is 170°C-200°C, the resistivity of the thermistor material in the area is less than 1Ω·cm, preferably less than or equal to 0.01Ω·cm.

[0072] When the hot spot temperature reaches the first temperature, the resistivity of the thermistor material 42 is less than the preset value. At this time, the leakage current flows through the thermistor material 42, and the temperature of the temperature control film 4 may still rise. When the temperature rises, the resistivity of the thermistor material 42 further decreases, and the heat generated becomes smaller and smaller until the temperature no longer continues to rise, thereby controlling the temperature below 170°C-200°C.

[0073] In the embodiment of the utility model, by setting the resistivity of the thermistor material 42 to be less than or equal to 0.01Ω·cm at a temperature of 170°C-200°C, it is possible to ensure that the resistivity of the thermistor material 42 drops rapidly within a rapid temperature drop range, thereby preventing the temperature of the temperature control film 4 from rising too high after the leakage current flows through the thermistor material 42.

[0074] Reference Figures 1 to 5 , Embodiment 1:

[0075] Reference Figures 3 to 5 The photovoltaic device is a photovoltaic laminate. The temperature control film 4 includes a film body 41 . The film body 41 has grid-shaped grooves 411 near the battery cell 31 . Adjacent grooves 411 are connected. Thermistor material 42 is filled in the grooves 411 .

[0076] Specifically, the shape of the grid can be designed according to the needs of conductivity and process, such as any one of a triangle, a rectangle, and a polygon, including a pentagon, a hexagon, and the like. Figure 3 The shape of the grid is rectangular. Figure 4 The shape of the middle grid is hexagonal. A groove 411 can be formed on the surface of the adhesive film body 41 close to the battery string group 3 by compression molding. The connection of the thermistor material 42 in the groove 411 is ensured by the setting of the grid-shaped groove 411. The width and depth of the groove 411 can be set according to actual needs, and the depth of the groove 411 is less than the thickness of the adhesive film body 41 itself. The thickness of the adhesive film body 41 itself can be less than 1mm. In the embodiment of the utility model, by having a grid-shaped groove 411, the contact area between the adhesive film body 41 and the battery string group 3 is ensured, which is conducive to the attachment of the temperature control film 4 to the battery string group 3.

[0077] Reference Figure 2 , the battery cell 31 is divided into n sub-batteries, n is a positive integer greater than or equal to 3, each sub-battery is equivalent to an equivalent battery 7, n equivalent batteries 7 are connected in parallel, the area on the temperature control film 4 corresponding to the battery cell is divided into n sub-areas, the n sub-areas correspond to the n sub-batteries respectively, each sub-area is equivalent to an equivalent resistor 8, and the equivalent resistor 8 is connected in parallel with the equivalent battery 7. Figure 2 As shown, for ease of understanding, a whole battery cell is equivalently divided into n sub-cells, and each sub-cell is connected in parallel. The total current I of the battery cell is the sum of the currents of each sub-cell.

[0078] In the absence of the temperature control film 4, when the nth sub-cell is blocked, there is no photocurrent, In is equal to 0, and the total current I of the cell will be less than the current of other cells, but because the cell is in series with other cells, other cells can still generate current I, which will generate a reverse bias voltage on the blocked cell. Due to the existence of the reverse bias voltage, local leakage will occur in the weak area of ​​the cell, such as the kth sub-cell, and due to the excessive local current, the area will continue to heat up and the temperature will rise until the blockage is removed or the cell breaks down.

[0079] When the temperature control film 4 is used, it is equivalent to connecting multiple equivalent resistors 8 in parallel on the back of the battery cell. When a part of the battery cell, such as the nth cell, is blocked and a hot spot occurs in the kth cell, the leakage current flows through the kth cell, causing the temperature of the hot spot area to rise rapidly. When the temperature of the hot spot area rises, the temperature of the corresponding area on the temperature control film 4 in contact with the hot spot area rises. When the temperature rises to the first temperature, the resistivity of the thermistor material 42 is less than the preset value, and the equivalent resistor R k The resistance value drops rapidly. Since the P-type region and the N-type region of the IBC battery are both located on the back of the battery cell, the reverse bias potential difference when the hot spot occurs is also generated on the back of the battery cell. This potential difference will also be loaded on the thermistor material 42. As the temperature of the hot spot increases, when it reaches the first temperature, the equivalent resistance R k When the resistance value of the kth cell in the leakage area drops below the resistance of the kth cell, the leakage current will flow from the equivalent resistance R k , that is, the thermistor material 42 passes through, thereby avoiding excessive leakage current inside the k-th slice battery, playing a role of local precise bypass protection, and the temperature of the k-th slice battery will no longer rise.

[0080] When the hot spot temperature is lower than the first temperature, the current will leak through the inside of the battery cell. When the temperature reaches the first temperature, the current will flow through the thermistor material 42. At this time, the temperature of the temperature control film 4 may still rise, but due to the temperature increase, the resistivity of the thermistor material 42 further decreases, and the heat generated becomes smaller and smaller until the temperature no longer continues to rise, thereby controlling the temperature below the upper limit of the temperature rapid drop interval. The two key temperature points of the lower limit and upper limit of the temperature rapid drop interval can be controlled by material design and selection.

[0081] Since the temperature control film will only be activated when the temperature is higher than the first temperature, and hot spots only occur in areas with large leakage, the temperature control film will only provide protection when hot spots occur and the temperature is greater than or equal to the first temperature, and will not affect non-hot spot areas.

[0082] Based on the above, it can be seen that when a hot spot occurs in any area on the battery cell, it can be bypassed by a parallel equivalent resistor.

[0083] The thermistor material 42 is formed by curing negative temperature coefficient conductive ink, where the negative temperature coefficient conductive ink includes a negative temperature coefficient filler.

[0084] Specifically, the temperature control film 4 is manufactured using a hybrid printing additive manufacturing technology, that is, the film body 41 is first manufactured, and a groove 411 is formed on the surface of the film body 41 near the battery string group 3 by compression molding, and negative temperature coefficient conductive ink is scraped and filled in the groove 411. After the negative temperature coefficient conductive ink is cured, a complete temperature control film 4 is formed. The negative temperature coefficient conductive ink is cured to form the thermistor material 42, so that the conductivity of the manufactured thermistor material 42 is negatively correlated with the temperature.

[0085] The negative temperature coefficient conductive ink includes a negative temperature coefficient (NTC) filler, a conductive additive a and a conductive additive b. The ratio of the negative temperature coefficient conductive ink, the characteristics under different ratios and the average hot spot temperature of the photovoltaic module using the negative temperature coefficient conductive ink of the ratio are shown in Table 1.

[0086] Table 1

[0087]

[0088]

[0089] According to Table 1, in terms of weight, the NTC filler in the negative temperature coefficient conductive ink is 70-90 parts, the conductive aid a is 0-4 parts, and the conductive aid b is 0-3 parts. The components of the conductive aid a, in terms of weight, may include the following components: 3-35 parts of epoxy resin, 0.5-15 parts of active diluent, 0-1 part of coupling agent a, 0-1 part of defoaming agent, and 0-1 part of toughening agent. The components of the conductive aid b, in terms of weight, may include the following components: 50-99 parts of curing agent, 0.5-50 parts of accelerator, and 0.1-5 parts of coupling agent b.

[0090] The epoxy resin is selected from one or more of liquid bisphenol A epoxy resin, bisphenol F epoxy resin and phenolic epoxy resin, the reactive diluent is selected from one or more of o-toluene glycidyl ether, butyl glycidyl ether, butanediol glycidyl ether and polyethylene glycol diglycidyl ether. The coupling agent a is selected from one or more of silane coupling agent, titanate coupling agent and zirconium aluminate coupling agent, the defoamer is selected from one or more of phosphate, organosilicon, fatty acid and fatty acid ester. The toughening agent is selected from one or more of nano titanium oxide, white carbon black and organic bentonite. The above-mentioned conductive aid a is selected from the complex composed of silver nitrate and / or silver acetate and glycidyl ether, preferably a complex composed of silver nitrate and / or silver acetate and o-toluene glycidyl ether, a complex composed of silver nitrate and / or silver acetate and butyl glycidyl ether, a complex composed of silver nitrate and / or silver acetate and butanediol glycidyl ether, and a complex composed of silver nitrate and / or silver acetate and polyethylene glycol diglycidyl ether. One or more of the complexes.

[0091] The curing agent is selected from one or more of fatty amines, modified fatty amines, polyetheramines and polyamides, and the accelerator is selected from tertiary amines and / or carboxylates of tertiary amines. The coupling agent b is selected from one or more of silane coupling agents (KH550, KH560, KH570, KH580), titanate coupling agents (KR238, 401), and zirconium aluminate coupling agents. The conductive additive b is selected from one or more of ascorbic acid VC, vitamin E, fructose, lactose and glucose. The NTC filler is selected from Ba with surface fatty acid modification. 1-X V X TiO3, Cu(Bi 1-x Sm x )2O4, La-Mn-O based core materials and Ba-Sr-Ti-O based shell materials, etc.

[0092] NTC fillers account for a high proportion in negative temperature coefficient conductive inks. At high temperatures, the resistivity of the NTC fillers themselves is greatly reduced, and they become conductive particles. Due to the high proportion of NTC fillers, after the ink is cured, the volume of the adhesive shrinks due to the volatilization of the solvent and the curing of the adhesive, and the filler particles are in contact with each other, so that the fillers are in a stable continuous state, thus showing conductivity. In addition, at the microscopic level, there is also the possibility of gaps between filler particles. At this time, there is another conductive mechanism, that is, when the directional movement of free electrons in the filler is hindered, this obstacle can be regarded as a potential barrier with a certain potential energy. According to the concept of quantum mechanics, for a microscopic particle, even if its energy is less than the energy of the potential barrier, it is possible to penetrate the potential barrier. This is the tunneling effect. Electrons are microscopic particles, so they have the possibility of passing through the isolation layer between filler particles. The probability of electron penetration is related to the thickness of the isolation layer, the energy of the isolation layer potential barrier and the energy of the electron. When the thickness of the isolation layer is small to a certain value, electrons can easily pass through this thin isolation layer, making the isolated NTC fillers conductive to each other, thereby achieving conductivity at high temperatures.

[0093] For example, in Example 1 of Table 1, the negative temperature coefficient conductive ink includes 87 parts of NTC filler,

[0094] At this time, the curing temperature of the negative temperature coefficient conductive ink is 100° C. The resistivity of the manufactured thermistor material 42 at 25° C. is 10×10 8 Ω·cm, the resistivity at 65℃ is 8×10 7 Ω·cm, the resistivity at 100℃ is 9×10 4 Ω·cm, the resistivity at 140°C is 13Ω·cm, the resistivity at 170°C is 0.03Ω·cm, and the shear strength is 19.5 MPa. When a hot spot occurs in a photovoltaic module using the thermistor material 42, the average temperature of the hot spot is 160°C.

[0095] Hot spot tests were performed on photovoltaic modules including thermistor materials 42 prepared from different negative temperature coefficient conductive inks in Examples 1 to 8, and the average hot spot temperatures when hot spots occurred in photovoltaic modules are shown in Table 1. The hot spot temperature of a conventional 72-piece photovoltaic module without using the temperature control film 4 is between 180°C and 200°C. The use of the temperature control film 4 effectively reduces the temperature of the photovoltaic module when hot spots occur.

[0096] The temperature control film 4 covers the battery string group 3 including a plurality of battery cells; or, the temperature control film 4 includes a plurality of temperature control sub-films, and the plurality of temperature control sub-films respectively cover a plurality of battery cells 31 .

[0097] Specifically, the temperature control film 4 can be a whole structure, in which case the size of the temperature control film 4 is the same as the size of the battery string 3. The temperature control film 4 can also be cut into a plurality of temperature control sub-films, the size of the temperature control sub-films being consistent with the size of the battery cell 31. In the embodiment of the utility model, through the above arrangement, it is ensured that when a hot spot occurs in any battery cell 31 in the battery string 3, the hot spot area thereon can be bypassed by the thermistor material 42 in the temperature control film 4.

[0098] The material of the adhesive film body 41 is ethylene-vinyl acetate copolymer (EVA) or polyolefin elastomer (POE). The adhesive film body 41 is pre-cured, and the pre-crosslinking degree of the adhesive film body 41 is 10%-60%.

[0099] Specifically, in order to ensure that the temperature control film 4 has a certain shape retention ability and does not cause the shape of the groove to be destroyed due to flow during the later photovoltaic module lamination, the film body 41 is pre-cured by heat during the molding process and has a pre-crosslinking degree of 10%-60%. The pre-crosslinking degree of the film body 41 can be 10%, 30%, 35%, 40%, 45%, 60%, etc.

[0100] The width of the groove 411 is 5 micrometers to 500 micrometers, and the ratio of the width of the groove 411 to the depth of the groove 411 is 0.1-2.

[0101] Specifically, the width of the groove 411 can be 5 microns, 20 microns, 50 microns, 80 microns, 100 microns, 500 microns, etc. The ratio of the width of the groove 411 to the depth of the groove 411 can be 0.1, 1, 1.5, 1.6, 1.8, 2, etc. In the embodiment of the utility model, by setting the width and depth of the groove 411 within the above range, it is ensured that the groove 411 can accommodate a certain amount of thermistor material 42, while avoiding the problem that the width of the groove 411 is too wide, which is not conducive to the attachment of the temperature control film 4 to the battery string group 3.

[0102] Reference Figures 6 to 10 , Figure 6When a part of a battery cell 31 is blocked, a hot spot occurs. Figures 7 and 8 , the leakage current flows through the inside of the battery cell 31, the temperature of the hot spot area increases, and the temperature of the thermistor material 42 corresponding to the hot spot area increases, thereby conducting electricity. Since the fine grid lines of the IBC battery are alternately distributed and the spacing is very small, when the thermistor material 42 conducts electricity, the positive grid line is connected to the negative grid line, referring to Fig. 9 and Fig.10 , the current will flow through the thermistor material 42 instead of flowing through the inside of the battery cell 31, thereby avoiding excessively high hot spot temperature caused by excessive current density inside the battery cell, thereby ensuring the safety of the battery cell.

[0103] The principle of the temperature control film 4 is equivalent to connecting a micro bypass in parallel in the hot spot area of ​​the battery cell, and its size depends on the size of the hot spot area. After the thermistor material 42 corresponding to the hot spot area is conductive, the hot spot area will no longer generate electricity, but other battery cells in the battery string will still generate electricity normally. The overall reduction in power generation of the photovoltaic module can be ignored, which is much lower than the bypass diode of the conventional photovoltaic module, which brings about a power generation drop of at least 1 / 3.

[0104] Reference Figures 11 to 14 , Embodiment 2:

[0105] The photovoltaic device is a cell, and the first side is the backlight side of the cell.

[0106] Specifically, the battery cell 31 is a back contact battery cell, and the temperature control film 4 is arranged on the backlight surface of the back contact battery cell. The battery cell 31 is specifically an interdigitated back contact battery, that is, an IBC battery. The material of the temperature control film 4 includes a thermistor material, and the thermistor material includes a negative temperature coefficient thermistor material and a conductive additive. The negative temperature coefficient thermistor material includes at least one of Mn-Co-Ni-O system materials, Co-Fe-O system materials, rare earth perovskite structure materials, Re(Cr, Mn)O3 system materials, BaTiO3-based materials, (Ba, Sr)BiO3 system thermistor materials, and (Ba, Sr)FeO3 system materials. The conductive additive includes metals such as copper and silver compounds. The mass proportion of the negative temperature coefficient thermistor material is 95%-100%, and the mass proportion of the conductive additive is 0%-5%.

[0107] In the embodiment of the utility model, a separate battery cell 31 coated with a temperature control film 4 itself has the function of preventing the hot spot temperature from being too high; there is no electrode on the front side of the back-contact battery, and both the positive and negative electrodes are arranged on the backlight side of the battery cell, thereby reducing the blocking of the electrode on the front side of the battery cell, increasing the light-receiving area of ​​the front side of the battery cell, and improving the energy conversion efficiency of the battery cell.

[0108] Reference Fig.12 and Fig.13The positive and negative electrodes include a plurality of positive grid lines 311 and a plurality of negative grid lines 312, and the temperature control film 4 covers at least one adjacent positive grid line 311 and one adjacent negative grid line 312. When the temperature of the hot spot area on the battery cell 31 reaches the first temperature, the internal circuit at the corresponding position of the battery cell 31 is short-circuited through the positive grid line 311 and the negative grid line 312.

[0109] The positive grid lines 311 and the negative grid lines 312 are thin grid lines, and the plurality of positive grid lines 311 and the plurality of negative grid lines 312 are sequentially staggered and arranged in a forked shape along the first direction. Along the first direction, the plurality of positive grid lines 311 and the plurality of negative grid lines 312 have overlapping areas, and the temperature control film 4 covers at least a portion of the overlapping areas. The temperature control film 4 covers the ends of the plurality of positive grid lines 311 and the plurality of negative grid lines 312.

[0110] Specifically, for a busbar-free cell, the positive grid lines 311 and the negative grid lines 312 are thin grid lines. Fig.12 The direction is indicated by the arrow A. In the embodiment of the utility model, the temperature control film 4 covers the ends of the plurality of positive electrode grid lines 311 and the plurality of negative electrode grid lines 312, so that the positive electrode grid lines 311 and the negative electrode grid lines 312 can be insulated and covered.

[0111] Reference Fig.13 The positive and negative electrodes also include a positive busbar 313 and a negative busbar 314. The positive busbar 313 is connected to a plurality of positive grid lines 311, and the negative busbar 314 is connected to a plurality of negative grid lines 312. The temperature control film 4 is disposed between the positive busbar 313 and the negative busbar 314. The temperature control film 4 is a plurality of discontinuous sub-films 43, each of which is located between adjacent positive busbars 313 and negative busbars 314.

[0112] Specifically, in the interdigitated back contact battery, the positive busbar 313 and the negative busbar 314 are arranged in parallel, the positive grid lines 311 and the negative grid lines 312 are arranged in a finger-shaped cross-arrangement, and the grid lines and the busbars of the same polarity are connected to each other, and the grid lines and the busbars of different polarities are isolated from each other to avoid short circuits. In the prior art, in order to prevent the grid lines and the busbars of different polarities from contacting after the battery cell has been used for a long time, that is, the positive busbar contacts the negative grid line or the negative busbar contacts the positive grid line, an insulating glue (green glue) is added to the battery cell.

[0113] The negative electrode grid line 312 has a suspended end portion close to the positive electrode bus bar 313, and the positive electrode grid line 311 has a suspended end portion close to the negative electrode bus bar 314. Fig.13If the two edges of the sub-membrane 43 are between the suspended end of the positive grid line 311 and the suspended end of the negative grid line 312, such as the two edges are respectively at positions C and D, then the suspended end of the positive grid line 311 and the suspended end of the negative grid line 312 not covered by the sub-membrane 43 are exposed to each other. At this time, there is a possibility of contact between the grid lines and the bus bars of different polarities.

[0114] Reference Fig.13 , the two edges A and B of the sub-film 43 are between the busbar of one electrode and the suspended end of the grid line of the other electrode, the edge A is between the positive busbar 313 and the suspended end of the negative grid line 312, and the edge B is between the negative busbar 314 and the suspended end of the positive grid line 311. When the sub-film 43 is plated on the battery cell 31 by magnetron sputtering, the coating range is between A and B and does not cover the pad. This coating range can ensure that the suspended end of the grid line that is not connected to the busbar is completely covered by the sub-film 43. The sub-film 43 covers the suspended end of the negative grid line 312 and the suspended end of the positive grid line 311, and when the temperature is less than or equal to the highest normal operating temperature of the battery cell, the temperature control film 4 is in an insulating state. Therefore, the positive grid line 311 and the negative grid line 312 can be insulated and covered, thereby replacing the insulating glue, and there is no need to set up additional insulating glue.

[0115] The sub-film 43 has a first edge close to the positive electrode bus grid 313 and a second edge close to the negative electrode bus grid 314. The distance between the first edge and the suspended end of the negative electrode grid line 312 is greater than or equal to 0, and is smaller than the distance between the suspended end of the negative electrode grid line 312 and the positive electrode bus grid 313. The distance between the second edge and the suspended end of the positive electrode grid line 311 is greater than or equal to 0, and is smaller than the distance between the suspended end of the positive electrode grid line 311 and the negative electrode bus grid 314. The first edge can refer to Fig.13 The edge shown in A, the second edge can refer to Fig.13 The distance between the first edge and the suspended end of the negative electrode grid line 312, specifically the distance between the first edge and the suspended end of the negative electrode grid line 312 connected to the negative electrode bus bar 314, is shown in FIG. Fig.13 The distance between the suspended end of the negative electrode grid line 312 and the positive electrode bus bar 313 is shown in L1. Fig.13 In the L2 shown in FIG, L1 is greater than or equal to 0 and less than L2.

[0116] The positive electrode bus bar 313 is connected to a positive electrode pad, the negative electrode bus bar 314 is connected to a negative electrode pad, and the sub-membrane 43 may be located between adjacent positive electrode pads and negative electrode pads.

[0117] The temperature control film 4 is a single continuous film disposed on the first surface of the battery cell 31 , and the temperature control film 4 exposes the soldering pad 315 of the battery cell.

[0118] Specifically, the shape of the pad can be a rectangle. A notch is provided on the temperature control film 4, and the notch is used to expose the position of the pad 315. In the embodiment of the utility model, the temperature control film 4 does not cover the pad 315, thereby ensuring that the circuit is normally connected after the battery cell is serially soldered through the solder ribbon, and avoiding the circuit being unable to be connected due to the insulation of the pad.

[0119] The temperature control film 4 is formed on the first surface of the battery cell 31 by deposition.

[0120] Specifically, the temperature control film 4 can be deposited on the first surface of the battery cell 31 by magnetron sputtering. Fig.12 The temperature control film 4 is a plurality of discontinuous sub-films 43, each of which is located between adjacent positive bus bars 313 and negative bus bars 314. The method for processing a battery cell coated with the temperature control film includes: providing a battery cell; shielding the positive bus bar, the negative bus bar, and the pad on the first side of the battery cell with a shielding object; coating the temperature control film on the first side of the battery cell by deposition; removing the shielding object to obtain a battery cell coated with the temperature control film.

[0121] The shielding object 9 includes a shielding frame or a shielding rubber strip. The positive busbar, negative busbar, and pad on the first side of the battery cell are shielded by a shielding object, including: covering the positive busbar, negative busbar, and pad on the first side of the battery cell with a shielding frame; or, sticking a shielding rubber strip on the positive busbar, negative busbar, and pad on the first side of the battery cell. A temperature control film is deposited on the first side of the battery cell, including: using any of magnetron sputtering, spin coating, and evaporation to deposit a temperature control film on the first side of the battery cell.

[0122] The magnetron sputtering method mainly uses a magnetron sputtering deposition device to plate the target material of the thin film on the substrate. The resulting thin film has high purity, good density, good film uniformity, strong adhesion, low temperature requirements, and good controllability. A thin film with uniform thickness can be obtained on a large-area substrate. The principle of radio frequency magnetron sputtering is to use accelerated Ar+ (argon) to bombard the target material to achieve the deposition of a thin film on the substrate. Because it is deposited in a vacuum, the thin film prepared by the magnetron sputtering method produces very few impurities and defects, which is conducive to the conduction of the temperature control film when the temperature reaches the first temperature, and the thin film prepared by this method has a high effective utilization rate, and the target material can be used multiple times. Therefore, it is preferred to use magnetron sputtering to plate the temperature control film on the first side of the battery cell.

[0123] In a second aspect, the embodiment of the utility model further discloses a photovoltaic assembly, including any one of the above photovoltaic devices. The photovoltaic assembly also includes a frame and a junction box. Since the photovoltaic assembly includes the above photovoltaic device, it also has the beneficial effects of the above photovoltaic device, which will not be described in detail here.

[0124] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0125] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A photovoltaic device, characterized in that: It comprises a battery cell and a temperature control film arranged on a first surface of the battery cell, wherein the first surface of the battery cell comprises a positive electrode and a negative electrode, and the temperature control film is in contact with both the positive electrode and the negative electrode of the battery cell; and the resistivity of the temperature control film is negatively correlated with the temperature; The temperature control film has an insulating state and a conductive state. When the temperature of the first area of ​​the battery cell is within the normal operating temperature range of the battery cell, the second area on the temperature control film corresponding to the first area is in an insulating state. When the temperature of the first area reaches a first temperature, the second area is in a conductive state, and the second area short-circuits the first area, wherein the first temperature is greater than the maximum value of the normal operating temperature range.

2. The photovoltaic device according to claim 1, characterized in that: The temperature control film includes a thermistor material. When the temperature of the first area is greater than or equal to a first temperature, the resistivity of the thermistor material at a corresponding position of the first area is less than a preset value, and the temperature control film at least short-circuits the battery cell area corresponding to the first area.

3. The photovoltaic device according to claim 2, characterized in that: The first temperature is 106°C-140°C.

4. The photovoltaic device according to claim 3, characterized in that: The first temperature is 120°C-140°C. When the temperature of a certain area of ​​the temperature control film is 120°C, the resistivity of the thermistor material in this area is 5Ω·cm-300Ω·cm. When the temperature of a certain area of ​​the temperature control film is 140°C, the resistivity of the thermistor material in this area is 0.1Ω·cm-100Ω·cm.

5. The photovoltaic device according to claim 2, characterized in that: When the temperature of the first region is greater than the first temperature, as the temperature of the first region continues to increase, the resistivity of the thermistor material at a corresponding position of the first region gradually decreases.

6. The photovoltaic device according to claim 5, characterized in that: When the temperature of a certain area of ​​the temperature control film is 170° C.-200° C., the resistivity of the thermistor material in the area is less than 0.01Ω·cm.

7. The photovoltaic device according to claim 2, characterized in that: The thermistor material has an insulating state. When the temperature is less than or equal to the maximum value of the normal operating temperature range, the thermistor material is in the insulating state, and the temperature control film is in the insulating state.

8. The photovoltaic device according to claim 7, characterized in that: When the thermistor material is in an insulating state, the resistivity of the thermistor material is greater than 10 4 Ω·cm.

9. The photovoltaic device according to claim 1, characterized in that: The battery cell is a back contact battery cell.

10. The photovoltaic device according to claim 1, characterized in that: The positive and negative electrodes include positive electrode grid lines and negative electrode grid lines, and / or positive electrode connecting lines and negative electrode connecting lines.

11. The photovoltaic device according to claim 10, characterized in that: The positive electrode connecting wire and the negative electrode connecting wire are metal connecting wires.

12. The photovoltaic device according to claim 2, characterized in that: The photovoltaic device is a photovoltaic laminate, and the temperature control film further comprises a film body. The surface of the film body close to the battery sheet has grid-shaped grooves, and the thermistor material is filled in the grooves.

13. The photovoltaic device according to claim 12, characterized in that: The thermistor material is formed by curing negative temperature coefficient conductive ink, and the negative temperature coefficient conductive ink includes a negative temperature coefficient filler.

14. The photovoltaic device according to claim 12, characterized in that: The temperature control film covers a battery string group including a plurality of the battery cells; or, the temperature control film includes a plurality of temperature control sub-films, and the plurality of temperature control sub-films respectively cover a plurality of the battery cells.

15. The photovoltaic device according to claim 12, characterized in that: The material of the adhesive film body is ethylene-vinyl acetate copolymer or polyolefin elastomer. The adhesive film body is pre-cured, and the pre-crosslinking degree of the adhesive film body is 10%-60%.

16. The photovoltaic device according to claim 12, characterized in that: The width of the groove is 5 micrometers to 500 micrometers, and the ratio of the width of the groove to the depth of the groove is 0.1-2.

17. The photovoltaic device according to claim 10, characterized in that: The positive and negative electrodes include a plurality of positive electrode grid lines and a plurality of negative electrode grid lines, and the temperature control film at least covers one adjacent positive electrode grid line and one adjacent negative electrode grid line.

18. The photovoltaic device according to claim 17, characterized in that: The positive electrode grid lines and the negative electrode grid lines are thin grid lines, and a plurality of the positive electrode grid lines and a plurality of the negative electrode grid lines are staggered in sequence along a first direction and arranged in a forked finger shape. Along the first direction, the plurality of the positive electrode grid lines and the plurality of the negative electrode grid lines have an overlapping area, and the temperature control film at least covers a portion of the overlapping area.

19. The photovoltaic device according to claim 17, characterized in that: The temperature control film covers ends of the plurality of positive electrode grid lines and the plurality of negative electrode grid lines.

20. The photovoltaic device according to claim 17, characterized in that: The positive and negative electrodes further include a positive busbar and a negative busbar. The positive busbar is connected to a plurality of positive grid lines, and the negative busbar is connected to a plurality of negative grid lines.

21. The photovoltaic device according to claim 20, characterized in that: The temperature control film is arranged between the positive electrode busbar and the negative electrode busbar.

22. The photovoltaic device according to claim 20, characterized in that: The temperature control membrane is a plurality of discontinuous sub-membranes, and each of the sub-membranes is located between adjacent positive electrode bus bars and negative electrode bus bars.

23. The photovoltaic device according to claim 17, characterized in that: The temperature control film is a single continuous film arranged on the first surface of the battery cell, and the temperature control film exposes the current extraction position of the battery cell.

24. The photovoltaic device according to claim 1, characterized in that: The temperature control film is formed on the first surface of the battery cell by deposition.

25. A photovoltaic module, characterized in that: A photovoltaic device comprising any one of claims 1 to 24.

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