WO2025011358A1 - Photovoltaic module - Google Patents

Abstract

A photovoltaic module, for reducing the contact resistances respectively between positive and negative connection electrodes included in a back contact cell and a conductive backplane. The photovoltaic module comprises a conductive backplane and a back contact cell pack arranged on the conductive backplane and comprising a plurality of back contact cell strings. The conductive backplane comprises a conductive circuit layer and an insulating material layer located between the conductive circuit layer and the back contact cell pack. The insulating material layer is internally provided with a plurality of conductive window groups extending in a first direction and distributed at intervals in a second direction, each conductive window group comprising a plurality of conductive windows which are distributed at intervals in the first direction and have bottoms exposing the conductive circuit layer. Positive and negative connection electrodes included in each back contact cell are both coupled to the portions of the conductive circuit layer exposed to respective conductive windows, so that the plurality of back contact cell strings are connected in parallel and back contact cells in each back contact cell string are connected in series. Half of the maximum lateral dimension of a conductive window is greater than 2.5 mm and less than the distance between the adjacent positive and negative connection electrodes in the same back contact cell.

Description

A photovoltaic module Technical Field

The present application relates to the technical field of solar cells, and in particular to a photovoltaic module.

Background Art

A back-contact cell refers to a solar cell with no electrodes on the front of the cell, and the positive and negative electrodes are arranged on the back of the cell. This can reduce the shielding of the electrode on the cell, increase the short-circuit current of the cell, and improve the energy conversion efficiency of the cell.

However, in existing photovoltaic modules based on back-contact cells, there is a problem of large contact resistance between the back-contact cells and the conductive backplane, which is not conducive to improving the working performance of the photovoltaic modules.

Summary of the invention

The purpose of the present application is to provide a photovoltaic module for ensuring that the positive connection electrode and the negative connection electrode included in the back contact cell in the photovoltaic module have a larger contact area with the conductive back plate respectively, thereby reducing the contact resistance between the two and improving the working performance of the photovoltaic module.

The present application provides a photovoltaic module. The photovoltaic module includes: a conductive backplane, and a back contact battery group arranged on the conductive backplane. The conductive backplane includes a conductive circuit layer, and an insulating material layer located between the conductive circuit layer and the back contact battery group. The insulating material layer is provided with a plurality of conductive window groups extending along a first direction and spaced apart along a second direction, each conductive window group includes a plurality of conductive windows spaced apart along the first direction, and the bottom of each conductive window exposes the conductive circuit layer. The first direction is different from the second direction. Direction. The back-contact battery pack includes a plurality of back-contact battery strings extending along a third direction and spaced apart along a fourth direction, and the third direction is different from the fourth direction. Each back-contact battery string includes a plurality of back-contact batteries spaced apart along the third direction. The positive connection electrode and the negative connection electrode included in each back-contact battery are respectively coupled with the portion of the conductive circuit layer exposed at the corresponding conductive window, so that the plurality of back-contact battery strings are connected in parallel through the conductive circuit layer, and the plurality of back-contact batteries included in each back-contact battery string are connected in series through the conductive circuit layer. One-half of the maximum lateral dimension of the conductive window is greater than 2.5 mm and less than the spacing between adjacent positive connection electrodes and negative connection electrodes in the same back-contact battery, and the lateral dimension is the dimension in a direction parallel to the second direction.

When adopting the above technical solution, the conductive circuit layer included in the conductive backplane is a patterned conductor. Therefore, the positive connection electrode and the negative connection electrode included in different back contact cells are respectively coupled with the parts of the conductive circuit layer exposed at the corresponding conductive windows, so that multiple back contact cell strings can be connected in parallel through the conductive circuit layer, and the different back contact cells included in each back contact cell string can be connected in series through the conductive circuit layer, thereby realizing electrical connection between different back contact cells in the back contact battery group, so that the output voltage and output current of the photovoltaic module can meet the working requirements.

The insulating material layer included in the conductive backplane is a film layer with insulating properties, which is arranged between the conductive circuit layer and the back contact battery group, and has a conductive window for coupling. Based on this, the existence of the insulating material layer can not only limit the position where the positive connection electrode and the negative connection electrode included in each back contact battery are coupled with the conductive circuit layer respectively, so that different back contact batteries in the back contact battery group can be electrically connected in a preset manner through the patterned conductive circuit layer, but also prevent each back contact battery from The positive connection electrode in the back contact battery and the negative connection electrode in another back contact battery are connected to the conductive circuit layer through the conductive window to cause a short circuit, and at least the positive connection electrode and the negative connection electrode included in the same back contact battery are prevented from being short-circuited by connecting the conductive circuit layer through the conductive window, so that the photovoltaic module has higher electrical reliability. Secondly, compared with the existing conductive window with half of the maximum lateral dimension less than 2.5mm, when half of the maximum lateral dimension of the conductive window set in the insulating material layer in the present application is greater than 2.5mm and less than the spacing between the adjacent positive connection electrode and the negative connection electrode in the same back contact battery, the lateral dimension of the conductive window set in the above insulating material layer is larger. Based on this, in the actual manufacturing process, due to the increase in the size of the conductive window, when the insulating material layer and the conductive circuit layer are compounded, even if the relative positions of the insulating material layer and the conductive circuit layer are offset to a certain extent, at least most of the areas where the conductive circuit layer is coupled with the positive connection electrode and the negative connection electrode respectively can be exposed through the conductive window with the increased opening size, ensuring that the positive connection electrode and the negative connection electrode included in the back contact battery have a larger contact area with the conductive circuit layer respectively, reducing the contact resistance between the two, which is beneficial to improving the working performance of the photovoltaic module, and can also reduce the precision requirements for compounding the insulating material layer and the conductive circuit layer, thereby reducing the manufacturing difficulty of the photovoltaic module.

In a possible implementation, a plurality of conductive interconnection groups extending along a first direction and spaced apart along a second direction are provided on the backlight surface of the back contact battery. Each conductive interconnection group is located on a corresponding positive connection electrode or a negative connection electrode, and each conductive interconnection group includes a plurality of conductive interconnections spaced apart along the first direction. In the above case, the positive connection electrode and the negative connection electrode are respectively coupled to the conductive circuit layer through the plurality of conductive interconnections included in the corresponding conductive interconnection group. The lateral dimension of a portion at any position (height) along the first direction is smaller than the lateral dimension of a portion of the corresponding conductive window at the same position (height) along the first direction.

In the case of adopting the above technical solution, since the manufacturing cost of the conductive interconnection is lower than that of the positive connection electrode and the negative connection electrode whose materials usually include silver, compared with the method of increasing the height of the positive connection electrode and the negative connection electrode to ensure that the two can be coupled with the conductive circuit layer respectively, the method of forming the conductive interconnection on the partial area of the positive connection electrode and the partial area of the negative connection electrode to achieve the coupling of the positive connection electrode and the negative connection electrode with the conductive circuit layer is more conducive to reducing the manufacturing cost of the photovoltaic module. In addition, the lateral size of the portion of the conductive interconnection at any position (height) along the first direction is smaller than the lateral size of the portion of the corresponding conductive window at the same position (height) along the first direction. At this time, the lateral dimension of the portion of the conductive interconnect at any position (height) along the first direction is smaller than the lateral dimension of the portion of the corresponding conductive window at the same position (height) along the first direction. This can be regarded as the margin allowed for the position of the insulating material layer to be offset relative to the back contact battery group and the conductive circuit layer when the back contact battery group, the insulating material layer and the conductive circuit layer are composited. The actual offset amount (length) is within the margin, which can ensure that each area on the top of the conductive interconnect can be coupled with the corresponding part of the conductive circuit layer through the conductive window provided in the insulating material layer, thereby ensuring a smaller contact resistance between the back contact battery and the conductive circuit layer, while reducing the manufacturing difficulty of the photovoltaic module.

In one possible implementation, the difference between the lateral dimension of a portion of the conductive interconnect at any position (height) along the first direction and the lateral dimension of a portion of the corresponding conductive window at the same position (height) along the first direction is greater than 0 and less than or equal to 3 mm.

In the case of adopting the above technical solution, the difference between the lateral dimension of the portion of the conductive interconnect at any position (height) along the first direction and the lateral dimension of the portion of the corresponding conductive window at the same position (height) along the first direction is within the above range, which can prevent the position of the insulating material layer from being allowed to be offset relative to the back contact battery pack and the conductive circuit layer due to the small difference, and can further reduce the composite precision requirements between the insulating material layer and the conductive circuit layer while ensuring that the conductive interconnect can have a large actual coupling area with the conductive circuit layer through the conductive window set in the insulating material layer. Secondly, it can also prevent the conductive window from being exposed at the conductive window due to the large difference, which easily causes leakage of the portion of the back contact battery pack exposed at the conductive window through the conductive circuit layer, thereby reducing the risk of short circuit.

In a possible implementation, in the same back-contact battery, a minimum distance between a conductive interconnector located on each positive connection electrode and a negative electrode including a corresponding negative connection electrode is greater than or equal to 0.2 mm and less than or equal to 1.5 mm.

When the above technical solution is adopted, in the same back-contact battery, the minimum spacing between the conductive interconnect located on each positive connection electrode and the negative electrode including the corresponding negative connection electrode is within the above range, which can prevent leakage of the conductive interconnect located on each positive connection electrode and the negative electrode due to the small minimum spacing, thereby reducing the risk of short circuit; secondly, it can also prevent the minimum spacing between each positive connection electrode and the negative electrode in the same back-contact battery from being large due to the large minimum spacing, thereby ensuring that the back-contact battery has a high photoelectric conversion efficiency.

In one possible implementation, in the same back contact cell, the The minimum spacing between the conductive interconnect and the positive electrode including the corresponding positive connection electrode is greater than or equal to 0.2 mm and less than or equal to 1.5 mm. The beneficial effects in this case can be analyzed with reference to the beneficial effects of the minimum spacing between the conductive interconnect located on each positive connection electrode and the negative electrode including the corresponding negative connection electrode being greater than or equal to 0.2 mm and less than or equal to 1.5 mm in the same back contact battery described above, and will not be repeated here.

In a possible implementation, each conductive window group defines a plurality of layers spaced apart along a first direction, each layer is sorted according to its position in the first direction and is assigned a layer number consistent with the sorting, and each conductive window group includes a plurality of conductive windows each located in a different layer of the plurality of layers defined by the conductive window group, wherein in two adjacent conductive window groups, two conductive windows located in the same number of layers are staggered along the first direction. Conductive windows located in different numbers of layers in the same conductive window group are spaced apart along the first direction.

When the above technical solution is adopted, in the actual application process, the adjacent positive connection electrodes and negative connection electrodes included in the same back contact battery are respectively coupled with the parts of the conductive circuit layer exposed at the two adjacent conductive window groups. Based on this, when the spacing between the adjacent positive connection electrodes and negative connection electrodes included in the same back contact battery remains unchanged, when two conductive windows located at the same number of layers in two adjacent conductive window groups are staggered along the first direction, the lateral dimensions of the two conductive windows located at the same number of layers in the two adjacent conductive window groups along the second direction can be appropriately increased, and the two conductive windows will not be connected, that is, it is conducive to increasing the lateral dimensions of the conductive windows, and thus, while ensuring that the conductive interconnect can have a larger actual coupling area with the conductive circuit layer through the conductive windows arranged in the insulating material layer, the composite precision requirements between the insulating material layer and the conductive circuit layer can be further reduced.

In one possible implementation, the positive electrode and the negative electrode included in the back contact battery both include a plurality of bus electrodes and a plurality of collector electrodes. Among them, in each back contact battery, the bus electrodes included in the positive electrode and the negative electrode extend along the first direction and are alternately spaced along the second direction. Each bus electrode is connected to a collector electrode with the same polarity as itself. The collector electrodes included in the positive electrode and the negative electrode extend along the second direction and are alternately spaced along the first direction. Each collector electrode includes a plurality of collector electrode segments spaced along the second direction, and two adjacent collector electrode segments included in the same collector electrode are used to isolate the bus electrode with opposite polarity to itself. The positive connection electrode is the bus electrode included in the positive electrode, and the negative connection electrode is the bus electrode included in the negative electrode.

In the case of adopting the above technical solution, the back contact cell included in the photovoltaic module provided in the embodiment of the present application can be a main grid back contact cell, so as to expand the scope of application of the photovoltaic module provided in the present application in different application scenarios. In addition, compared with the back contact cell without a main grid, the distance between each two adjacent positive connection electrodes and negative connection electrodes included in the back contact cell with a main grid is larger, which is conducive to increasing the upper limit of the lateral size of the conductive window, and can further reduce the composite precision requirements between the insulating material layer and the conductive circuit layer.

In one possible implementation, one-half of the maximum lateral dimension of the conductive window is larger than the spacing between each collecting electrode segment and an adjacent bus electrode of opposite polarity to itself, and an insulating isolation portion is provided on the backlight surface of the back contact battery, and the insulating isolation portion is used to isolate the coupling point between the positive connecting electrode and the conductive circuit layer included in the same back contact battery from the negative electrode of the back contact battery, and to isolate the coupling point between the negative connecting electrode and the conductive circuit layer of the back contact battery from the positive electrode of the back contact battery.

When the above technical solution is adopted, when one half of the maximum lateral dimension of the conductive window is greater than In the case of the spacing between each collector electrode segment and the adjacent bus electrode with opposite polarity, each conductive window corresponding to the positive connection electrode will expose the partial area of the collector electrode segment with the smallest spacing from the positive connection electrode and included in the negative electrode. Similarly, each conductive window corresponding to the negative connection electrode will expose the partial area of the collector electrode segment with the smallest spacing from the negative connection electrode and included in the positive electrode. Based on this, the insulating isolation portion provided on the backlight surface of the back contact battery can isolate the coupling between the positive connection electrode and the conductive circuit layer included in the same back contact battery from the negative electrode, and isolate the coupling between the negative connection electrode and the conductive circuit layer from the positive electrode, further reducing the risk of leakage of the back contact battery pack through the conductive circuit layer after the lateral size of the conductive window becomes larger.

In a possible implementation, when the geometric center of the projection area of each conductive window on the backlight surface coincides with the geometric center of the corresponding coupling point, the projection area is the target area. In the above case, a plurality of insulating isolation parts extending along the first direction and spaced apart along the second direction are provided on the backlight surface of the back contact battery. Each insulating isolation part includes a plurality of insulating isolation members spaced apart along the first direction. Moreover, each insulating isolation member corresponding to the positive connection electrode at least covers the portion of the negative electrode exposed at the corresponding target area. Each insulating isolation member corresponding to the negative connection electrode at least covers the portion of the positive electrode exposed at the corresponding target area.

In the case of adopting the above technical solution, in the actual manufacturing process, when the relative positions of the insulating material layer and the conductive circuit layer are not offset when they are combined, the geometric center of the projection area of each conductive window on the backlight surface coincides with the geometric center of the corresponding coupling point. Based on this, when the geometric center of the projection area of each conductive window on the backlight surface coincides with the geometric center of the corresponding coupling point, the projection area For the target area. In this case, each insulating spacer corresponding to the positive connection electrode at least covers the portion of the negative electrode exposed at the corresponding target area, which can not only cover the portion of the negative electrode exposed at the conductive window corresponding to the positive connection electrode through the insulating spacer to prevent leakage, but also reduce the amount of consumables used in the insulating isolation part, which is beneficial to controlling the manufacturing cost of the photovoltaic module. Similarly, each insulating spacer corresponding to the negative connection electrode at least covers the portion of the positive electrode exposed at the corresponding target area, which can not only cover the portion of the positive electrode exposed at the conductive window corresponding to the negative connection electrode through the insulating spacer to prevent leakage, but also reduce the amount of consumables used in the insulating isolation part.

In one possible implementation, the lateral dimension of a portion of each insulating spacer corresponding to the positive connecting electrode at any position (height) along the first direction is larger than the lateral dimension of a portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction.

When the above technical solution is adopted, the amount (length) by which the lateral dimension of a portion of each insulating spacer corresponding to the positive connecting electrode at any position (height) along the first direction is larger than the lateral dimension of a portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction can be regarded as a margin allowed for the insulating material layer and the conductive circuit layer to be offset when they are composited. When the insulating material layer and the conductive circuit layer are offset when they are composited, the actual offset amount (length) is within the range of the margin, and the collector electrode included in the negative electrode exposed at the conductive window can be covered by the insulating spacer, thereby increasing the conductive window while reducing the risk of leakage of the back contact battery pack through the conductive circuit layer.

In a possible implementation, each insulating spacer corresponding to the negative connection electrode is provided along the first The lateral dimension of the portion at any position (height) in one direction is greater than the lateral dimension of the portion of the collector electrode included in the positive electrode exposed in the corresponding target area at the same position (height) along the first direction. The beneficial effects in this case can be analyzed with reference to the beneficial effects of the lateral dimension of the portion of each insulating spacer corresponding to the positive connecting electrode at any position (height) along the first direction being greater than the lateral dimension of the portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction, which will not be repeated here.

In a possible implementation, the lateral dimension of the conductive window corresponding to the positive connection electrode is smaller than the longitudinal dimension of the conductive window, so that the coupling between the positive connection electrode and the conductive circuit layer and the collector electrode included in the negative electrode are isolated by the insulating material layer. The longitudinal dimension is the dimension in the direction parallel to the first direction.

In the case of adopting the above technical solution, while at least the longitudinal dimension of the conductive window corresponding to the positive connection electrode is enlarged, thereby increasing the allowance for the insulating material layer to be offset relative to the back contact battery group and the conductive circuit layer along its own longitudinal dimension direction when the back contact battery group, the insulating material layer and the conductive circuit layer are composited, because the collector electrode included in the same back contact battery extends along the second direction, it is also possible to provide a conductive window with a smaller transverse dimension in the insulating material layer to ensure that the insulating material layer can isolate the collector electrode included in the negative electrode near each conductive window to prevent leakage. In addition, there is no need to provide an additional insulating spacer on the backlight surface of the back contact battery, simplifying the manufacturing process of the back contact battery group.

In a possible implementation, the lateral dimension of the conductive window corresponding to the negative connection electrode is smaller than the longitudinal dimension of the conductive window, so that the negative connection electrode and the conductive circuit layer are separated by the insulating material layer. The coupling part is separated from the collector electrode included in the positive electrode. The longitudinal dimension is the dimension in the direction parallel to the first direction. The beneficial effect in this case can be analyzed by referring to the beneficial effect analysis of the lateral dimension of the conductive window corresponding to the positive connection electrode being smaller than the longitudinal dimension of the conductive window as described above, which will not be repeated here.

In a possible implementation, the first direction is parallel to the third direction, and the second direction is parallel to the fourth direction. Or, the first direction is parallel to the fourth direction, and the second direction is parallel to the third direction.

When adopting the above technical solution, the distribution relationship of the positive connection electrode and the negative connection electrode included in the back contact battery conforms to the distribution relationship of different back contact batteries in the same back contact battery string, and the distribution relationship between different back contact battery strings, so that the distribution of the positive connection electrode and the negative connection electrode is more regular, which is conducive to reducing the difficulty of setting a conductive window in the insulating material layer and reducing the difficulty of manufacturing a patterned conductive circuit layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application. In the drawings:

FIG1 is a schematic diagram of a structural distribution of a conductive window group arranged in an insulating material layer in an embodiment of the present application;

FIG2 is a schematic diagram of another structural distribution of a conductive window group disposed in an insulating material layer in an embodiment of the present application;

FIG. 3 is another structural distribution of the conductive window group arranged in the insulating material layer in the embodiment of the present application. Schematic diagram;

FIG4 is a schematic diagram showing a distribution of a projection of a conductive window group disposed in an insulating material layer on a backlight surface of a back contact cell in an embodiment of the present application;

5 is a schematic diagram showing another projection distribution of the conductive window group arranged in the insulating material layer on the backlight surface of the back contact battery in an embodiment of the present application;

6 is a schematic diagram showing the distribution of another projection of the conductive window group arranged in the insulating material layer on the backlight surface of the back contact cell in an embodiment of the present application;

FIG7 is a schematic diagram of a structural distribution of a positive electrode and a negative electrode included in a back contact battery in an embodiment of the present application;

FIG8 is a schematic diagram of another structural distribution of the positive electrode and the negative electrode included in the back contact battery in an embodiment of the present application;

FIG9 is a schematic diagram of a structural distribution of conductive interconnects on the positive connection electrode and the negative connection electrode in an embodiment of the present application;

FIG10 is a schematic diagram of another structural distribution of the conductive interconnectors on the positive connection electrode and the negative connection electrode in an embodiment of the present application;

FIG11 is a schematic diagram of a structural distribution of an insulating isolation portion provided on the backlight surface of a back contact battery in an embodiment of the present application;

FIG. 12 is a schematic diagram showing another structural distribution of an insulating isolation portion provided on the backlight surface of a back-contact battery in an embodiment of the present application.

Figure numerals: 1 is a back contact battery, 2 is a positive electrode, 3 is a negative electrode, 4 is a collecting electrode, 5 is a bus electrode, 6 is a collecting electrode segment, 7 is a conductive interconnection group, 8 is a conductive interconnection member, 9 is an insulating material layer, 10 is a conductive window group, 11 is a conductive window, 12 is an insulating isolation portion, and 13 is an insulating isolation member.

DETAILED DESCRIPTION

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must be It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present application.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

At present, solar cells are used more and more widely as a new energy alternative. Among them, photovoltaic solar cells are devices that convert sunlight energy into electrical energy. Specifically, solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead out the carriers, thereby facilitating the effective use of electrical energy. Among them, when the positive and negative electrodes included in the solar cell are both located on the back of the solar cell, the solar cell is a back-contact cell. Because the front of the back-contact cell is not affected by the metal electrode, it has a higher short-circuit current Isc, which is one of the current technical directions for realizing high-efficiency crystalline silicon cells.

In addition, in actual application, multiple back-contact cells are usually connected in series to form a back-contact cell string to increase the output voltage of the photovoltaic module, and multiple back-contact cell strings are connected in parallel to increase the output current, so that the output power of the photovoltaic module meets the working requirements. Specifically, the existing photovoltaic module includes a conductive circuit layer, an insulating material layer, a back-contact cell group layer, a packaging material layer and a transparent cover layer stacked together from bottom to top. Among them, the back-contact cell group layer includes a conductive circuit layer extending along the third direction and a back-contact cell group layer extending along the fourth direction. A plurality of back contact battery strings are spaced apart in a third direction, and each back contact battery string includes a plurality of back contact batteries spaced apart in a third direction. Different back contact battery strings are connected in parallel through a conductive circuit layer, and a plurality of back contact batteries included in the same back contact battery string are connected in series through a conductive circuit layer. The insulating material layer is used to isolate the back contact battery group layer from the conductive circuit layer to prevent short circuit. In addition, a plurality of conductive windows are provided through the insulating material layer to realize coupling between the back contact battery group layer and the conductive circuit layer.

However, in order to effectively collect the carriers generated by the back contact battery, the minimum spacing between the positive electrode and the negative electrode included in each back contact battery is small, resulting in the close arrangement of the collector electrode included in the positive electrode and the collector electrode included in the negative electrode around the coupling point between each back contact battery and the conductive circuit layer. In order to prevent the collector electrode included in the positive electrode and the collector electrode included in the negative electrode from being connected to the conductive circuit layer through the conductive window opened in the above-mentioned insulating material layer and causing a short circuit, the size of the conductive window set in the insulating material layer is limited. In this case, in the actual process of manufacturing the above-mentioned photovoltaic module, the composite precision between the insulating material layer and the conductive circuit layer is required to be high. If there is a relative offset between the insulating material layer and the conductive circuit layer, most of the areas where the positive connection electrode and the negative connection electrode included in the back contact battery are respectively coupled with the conductive circuit layer will be blocked by the offset insulating material layer, thereby causing the actual coupling area of the positive connection electrode and the negative connection electrode to be smaller than the preset solution, resulting in an increase in the contact resistance between the two, which is not conducive to improving the power of the photovoltaic module.

In order to solve the above technical problems, the embodiment of the present application provides a photovoltaic module. The photovoltaic module includes: a conductive backplane, and a back contact battery group arranged on the conductive backplane. The conductive backplane includes a conductive circuit layer, and an insulating material layer located between the conductive circuit layer and the back contact battery group. As shown in Figures 1 to 3 As shown, a plurality of conductive window groups 10 extending along the first direction and spaced apart along the second direction are provided in the insulating material layer 9, and each conductive window group 10 includes a plurality of conductive windows 11 spaced apart along the first direction, and the bottom of each conductive window 11 exposes the conductive circuit layer. The first direction is different from the second direction. The back contact battery group includes a plurality of back contact battery strings extending along the third direction and spaced apart along the fourth direction, and the third direction is different from the fourth direction. Each back contact battery string includes a plurality of back contact batteries spaced apart along the third direction. The positive connection electrode and the negative connection electrode included in each back contact battery are respectively coupled with the portion of the conductive circuit layer exposed at the corresponding conductive window 11, so that the plurality of back contact battery strings are connected in parallel through the conductive circuit layer, and the plurality of back contact batteries included in each back contact battery string are connected in series through the conductive circuit layer. One-half of the maximum lateral dimension of the conductive window 11 is greater than 2.5 mm and less than the spacing between adjacent positive connection electrodes and negative connection electrodes in the same back contact battery, and the lateral dimension is the dimension in the direction parallel to the second direction.

When the above technical solution is adopted, the conductive circuit layer included in the above conductive backplane can be a patterned conductor, so that the positive connection electrode and the negative connection electrode included in different back contact cells are respectively coupled with the parts of the conductive circuit layer exposed at the corresponding conductive windows, so that multiple back contact cell strings can be connected in parallel through the conductive circuit layer, and the different back contact cells included in each back contact cell string can be connected in series through the conductive circuit layer, thereby realizing electrical connection between different back contact cells in the back contact battery group, so that the output voltage and output current of the photovoltaic module can meet the working requirements.

The insulating material layer included in the conductive backplane may be a film layer with insulating properties, which is arranged between the conductive circuit layer and the back contact battery pack, and as shown in FIGS. 1 to 3, the insulating material layer 9 is provided with a Coupled conductive window 11. Based on this, the presence of the insulating material layer 9 can not only limit the position where the positive connection electrode and the negative connection electrode included in each back contact battery are coupled with the conductive circuit layer respectively, so that different back contact batteries in the back contact battery group can be electrically connected through the patterned conductive circuit layer and in a preset manner, but also prevent the positive connection electrode in each back contact battery from being short-circuited with the negative connection electrode in another back contact battery by connecting the conductive circuit layer through the conductive window 11, and at least inhibit the positive connection electrode and the negative connection electrode included in the same back contact battery from being short-circuited by connecting the conductive circuit layer through the conductive window 11, so that the photovoltaic module has higher electrical reliability. Secondly, compared with the existing conductive window with a maximum lateral dimension of less than 2.5 mm, as shown in Figures 4 to 6, when the maximum lateral dimension of the conductive window set in the insulating material layer in the present application is greater than 2.5 mm and less than the spacing between the adjacent positive connection electrode and the negative connection electrode in the same back contact battery, the lateral dimension of the conductive window set in the above insulating material layer is larger. Based on this, in the actual manufacturing process, due to the increase in the size of the conductive window, when the insulating material layer and the conductive circuit layer are compounded, even if the relative positions of the insulating material layer and the conductive circuit layer are offset to a certain extent, at least most of the areas where the conductive circuit layer is coupled with the positive connection electrode and the negative connection electrode respectively can be exposed through the conductive window with the increased opening size, ensuring that the positive connection electrode and the negative connection electrode included in the back contact battery have a larger contact area with the conductive circuit layer respectively, reducing the contact resistance between the two, which is beneficial to improving the working performance of the photovoltaic module, and can also reduce the precision requirements for compounding the insulating material layer and the conductive circuit layer, thereby reducing the manufacturing difficulty of the photovoltaic module.

In the actual application process, for the above-mentioned back contact battery pack, from the distribution point of view, In the same back-contact cell string, connecting different back-contact cells in series can increase the output voltage of the photovoltaic module; and connecting different back-contact cell strings in parallel can increase the output current of the photovoltaic module. Based on this, the number of back-contact cell strings included in the back-contact cell group and the number of back-contact cells included in each back-contact cell string can be determined according to the requirements for the output voltage and output current of the photovoltaic module in the actual application scenario.

As for the third direction and the fourth direction, they can be any two directions parallel to the backlight surface of the photovoltaic module and different from each other. Preferably, the contour of the backlight surface of the photovoltaic module includes a first side and a second side intersecting each other. The third direction and the fourth direction are parallel to the first side and the second side, respectively.

In addition, the extension direction and spacing distribution direction of the positive connection electrode and the negative connection electrode included in the back contact battery can be consistent with the extension direction of the conductive window group and the spacing distribution direction of different conductive window groups, respectively. In this case, the third direction can be parallel to the first direction, and the fourth direction is parallel to the second direction. At this time, the extension direction of the positive connection electrode and the negative connection electrode included in the back contact battery are parallel to the extension direction of the back contact battery string, and the alternating spacing arrangement direction of the positive connection electrode and the negative connection electrode is parallel to the arrangement direction of different back contact battery strings.

Alternatively, the third direction may be parallel to the second direction, and the fourth direction may be parallel to the first direction. In this case, the extension directions of the positive connection electrode and the negative connection electrode included in the back contact battery are parallel to the arrangement direction of different back contact battery strings, and the alternating arrangement direction of the positive connection electrode and the negative connection electrode is parallel to the extension direction of the back contact battery string.

In the above case, the distribution relationship of the positive connection electrode and the negative connection electrode included in the back contact battery is The distribution relationship between different back contact cells in the same back contact cell string, and the distribution relationship between different back contact cell strings, make the distribution of the positive connection electrode and the negative connection electrode more regular, which is conducive to reducing the difficulty of setting a conductive window in the insulating material layer and reducing the difficulty of manufacturing a patterned conductive circuit layer.

Of course, the third direction and the fourth direction may also be any two different directions that are different from the first direction and the second direction respectively and are parallel to the backlight surface of the back contact cell.

From a structural point of view, the embodiments of the present application do not specifically limit the structure of the back-contact battery, as long as the solar cell has both the positive electrode and the negative electrode located on the backlight side. Exemplarily, the back-contact battery may include a semiconductor substrate, a positive electrode and a negative electrode. The backlight side of the semiconductor substrate has N-type regions and P-type regions that are alternately spaced. The positive electrode and the negative electrode are both formed on the backlight side of the semiconductor substrate, and the positive electrode forms an ohmic contact with the P-type region, and the negative electrode forms an ohmic contact with the N-type region.

As for the positive electrode and negative electrode included in the above-mentioned back contact battery, the specific structures of the two can be determined according to the type of battery. For example, as shown in Figure 7, the above-mentioned back contact battery 1 can be a busbar-free back contact battery. At this time, in the busbar-free back contact battery, the collector electrodes 4 included in the positive electrode 2 and the negative electrode 3 extend along the first direction and are alternately arranged along the second direction. In addition, the positive connection electrode included in the above-mentioned back contact battery 1 is the collector electrode 4 included in the positive electrode 2, and the above-mentioned negative connection electrode is the collector electrode 4 included in the negative electrode 3.

Alternatively, as shown in FIG8 , the back contact battery 1 may also be a main grid back contact battery. In this case, the positive electrode 2 and the negative electrode 3 included in the back contact battery 1 each include a plurality of busbar electrodes 5 and a plurality of collector electrodes 4. In each back contact battery 1, the busbar electrodes 5 included in the positive electrode 2 and the negative electrode 3 extend along the first direction and are alternately spaced along the second direction. Each busbar electrode 5 is connected to a collector electrode 4 of the same polarity as itself. The positive electrode 2 and the negative electrode 3 are connected. The collector electrodes 4 included in the positive electrode 2 and the negative electrode 3 extend along the second direction and are alternately spaced along the first direction. Each collector electrode 4 includes a plurality of collector electrode segments 6 spaced along the second direction, and two adjacent collector electrode segments 6 included in the same collector electrode 4 are used to isolate the bus electrode 5 with opposite polarity to itself. The positive connection electrode is the bus electrode 5 included in the positive electrode 2, and the negative connection electrode is the bus electrode 5 included in the negative electrode 3.

It should be noted that a collector electrode included in the positive electrode has an opposite polarity to a collector electrode included in the negative electrode (or a bus electrode included in the negative electrode), and has the same polarity as another collector electrode included in the positive electrode (or a bus electrode included in the positive electrode). Similarly, a bus electrode included in the positive electrode has an opposite polarity to a collector electrode included in the negative electrode (or a bus electrode included in the negative electrode), and has the same polarity as another bus electrode included in the positive electrode (or a collector electrode included in the positive electrode). Accordingly, the situation of electrodes with the same or opposite polarity corresponding to the collector electrode and bus electrode included in the negative electrode can be referred to the previous text and will not be repeated here.

In addition, when the back contact cell is a main grid-free back contact cell, the number and morphology of the collector electrodes respectively included in the positive electrode and the negative electrode, and the size of the gap between the collector electrode included in the positive electrode and the collector electrode included in the adjacent negative electrode along the second direction can be set according to the actual application scenario, as long as they can be applied to the photovoltaic module provided in the embodiment of the present application; and when the back contact cell is a main grid back contact cell, the number and morphology of the collector electrodes and bus electrodes respectively included in the positive electrode and the negative electrode, the gap between the collector electrode included in the positive electrode and the collector electrode included in the adjacent negative electrode along the first direction, and the size of the gap between the bus electrode included in the positive electrode and the bus electrode included in the adjacent negative electrode along the second direction can be set according to the actual application scenario, As long as it can be applied to the photovoltaic components provided in the embodiments of the present application, it can be used.

It is worth noting that the back contact cell included in the photovoltaic module provided by the present application can be a back contact cell without a main grid, or a back contact cell with a main grid, so as to improve the applicability of the photovoltaic module provided by the present application in different application scenarios. In addition, as shown in Figures 7 and 8, compared with the back contact cell with a main grid, the structure of the positive electrode 2 and the negative electrode 3 included in the back contact cell without a main grid is simpler, which can make the pattern on the conductive circuit layer for realizing the electrical interconnection of different back contact cells simpler, and reduce the manufacturing difficulty of the conductive backplane. Compared with the back contact cell without a main grid, the distance between each adjacent two positive connection electrodes and negative connection electrodes included in the back contact cell with a main grid is larger, which is conducive to increasing the upper limit of the lateral size of the conductive window, and can further reduce the composite precision requirements between the insulating material layer and the conductive circuit layer. In this case, the specific structure of the positive electrode 2 and the negative electrode 3 included in the back contact battery, as well as the position of the positive connection electrode and the negative connection electrode included in the back contact battery can be determined according to the requirements of the actual application scenario.

In one example, as shown in FIG. 7 and FIG. 8 , a plurality of conductive interconnection groups 7 extending along a first direction and spaced apart along a second direction are provided on the backlight surface of the above-mentioned back-contact battery 1. Each conductive interconnection group 7 is located on a corresponding positive connection electrode or a negative connection electrode, and each conductive interconnection group 7 includes a plurality of conductive interconnections 8 spaced apart along the first direction. In the above case, the positive connection electrode and the negative connection electrode are respectively coupled to the conductive circuit layer through a plurality of conductive interconnections 8 included in the corresponding conductive interconnection group 7. The lateral dimensions of the portion of the conductive interconnection 8 at any position (height) along the first direction are smaller than the lateral dimensions of the portion of the corresponding conductive window at the same position (height) along the first direction. In this case, because the manufacturing cost of the conductive interconnection 8 is lower than that of the positive connection electrode and the negative connection electrode, the material of which usually includes silver, Therefore, compared with the method of increasing the height of the positive connection electrode and the negative connection electrode to ensure that they can be coupled with the conductive circuit layer respectively, the method of forming the conductive interconnection 8 on the partial area of the positive connection electrode and the partial area of the negative connection electrode to achieve the coupling of the positive connection electrode and the negative connection electrode with the conductive circuit layer respectively is more conducive to reducing the manufacturing cost of the photovoltaic module. In addition, the lateral size of the portion of the conductive interconnection 8 at any position (height) along the first direction is smaller than the lateral size of the portion of the corresponding conductive window at the same position (height) along the first direction. At this time, the lateral dimension of the portion of the conductive interconnect 8 at any position (height) along the first direction is smaller than the lateral dimension of the portion of the corresponding conductive window at the same position (height) along the first direction. This can be regarded as the margin allowed for the position of the insulating material layer to be offset relative to the back contact battery group and the conductive circuit layer when the back contact battery group, the insulating material layer and the conductive circuit layer are composited; the actual offset amount (length) is within the margin, which can ensure that each area on the top of the conductive interconnect 8 can be coupled with the corresponding part of the conductive circuit layer through the conductive window provided in the insulating material layer, thereby ensuring a smaller contact resistance between the back contact battery 1 and the conductive circuit layer, and reducing the manufacturing difficulty of the photovoltaic module.

Specifically, from the distribution aspect, as shown in FIG9 , each conductive window group defines a plurality of layers spaced apart and distributed along the first direction, each layer is sorted according to its position in the first direction and is assigned a number of layers consistent with its sorting, and each conductive window group includes a plurality of conductive windows each located in a different layer of the plurality of layers defined by the conductive window group, and in two adjacent conductive interconnection groups located on the backlight surface of the same back contact cell, two conductive interconnections 8 located in the same number of layers can be aligned and arranged along the first direction. Among them, the conductive interconnections 8 located in different numbers of layers in the same conductive interconnection group are spaced apart and distributed along the first direction. At this time, the distribution of different conductive interconnects 8 on the backlight surface of the back contact battery is relatively regular, which is conducive to reducing the difficulty of manufacturing the back contact battery.

For example, different conductive interconnection groups are sorted from left to right and from small to large, and the number of layers of different conductive interconnections in the same conductive interconnection group is sorted from top to bottom and from small to large (the above is also sorted in the above manner). As shown in FIG9 , the conductive interconnection 8 of the first layer in the conductive interconnection group in the first column along the first direction is aligned with the conductive interconnection 8 of the first layer in the conductive interconnection group in the second column.

Alternatively, as shown in FIG10, each conductive window group defines a plurality of layers spaced apart along the first direction, each layer is sorted according to its position in the first direction and is assigned a number of layers consistent with its sorting, and each conductive window group includes a plurality of conductive windows each located in a different layer of the plurality of layers defined by the conductive window group, and in two adjacent conductive interconnection groups located on the backlight surface of the same back contact cell, two conductive interconnections 8 located in the same number of layers may also be staggered along the first direction. For example, as shown in FIG10, the conductive interconnections 8 of the first layer in the conductive interconnection group in the first column along the first direction are staggered with the conductive interconnections 8 of the first layer in the conductive interconnection group in the second column.

It is worth noting that, because each conductive interconnect is coupled to the portion of the conductive circuit layer exposed at the corresponding conductive window, the distribution of different conductive interconnects arranged on the backlight surface of the back contact battery will affect the distribution of different conductive windows arranged in the insulating material layer. Based on this, when two conductive interconnects located on the backlight surface of the same back contact battery and located at the same number of layers in two adjacent conductive interconnect groups are staggered along the first direction, it is also beneficial to make the conductive windows located at different numbers of layers in two adjacent conductive window groups staggered. The two conductive windows are staggered along the first direction. In the above case, as shown in Figures 1 and 2, and Figures 5 and 6, in the actual application process, the adjacent positive connection electrodes and negative connection electrodes included in the same back contact battery are respectively coupled with the portions of the conductive circuit layer exposed at the two adjacent conductive window groups. Based on this, when the spacing between the adjacent positive connection electrodes and negative connection electrodes included in the same back contact battery remains unchanged, when the two conductive windows located in the same number of layers in the two adjacent conductive window groups are staggered along the first direction, the lateral dimensions of the two conductive windows located in the same number of layers in the two adjacent conductive window groups along the second direction can be appropriately increased, and the two conductive windows will not be connected, that is, it is conducive to increasing the lateral dimensions of the conductive windows, and then it can ensure that the conductive interconnect 8 can have a larger actual coupling area with the conductive circuit layer through the conductive window set in the insulating material layer 9, and the composite precision requirements between the insulating material layer 9 and the conductive circuit layer can be further reduced. Among them, in Figures 5 and 6, the circular dotted line is the projection outline of the conductive window on the backlight surface.

From a structural perspective, each conductive interconnection may include only a welding portion for interconnecting the positive connection electrode with the conductive circuit layer, or only a welding portion for interconnecting the negative connection electrode with the conductive circuit layer. The longitudinal section of the welding portion may be square, rectangular, circular or elliptical.

Alternatively, each conductive interconnect may further include an interconnect portion located on the soldering portion. The cross-sectional area of the interconnect portion is less than or equal to the cross-sectional area of the soldering portion. The morphology of the interconnect portion may be determined according to actual needs and is not specifically limited herein. In addition, the interconnect portion may be a component such as a conductive adhesive or solder paste for assisting interconnection.

In terms of morphology, the specifications of each conductive interconnect, the number of conductive interconnects included in each conductive interconnect group, the distance between two adjacent conductive interconnects in the same conductive interconnect group, and the distance between two adjacent conductive interconnects. The spacing between different conductive interconnects in the electrical interconnect group, and the difference between the lateral dimensions of the portion of the conductive interconnect at any position (height) along the first direction and the lateral dimensions of the portion of the corresponding conductive window at the same position (height) along the first direction, affect the coupling area between the positive connection electrode and the negative connection electrode and the conductive circuit layer, respectively, and the size of the conductive window provided in the insulating material layer. Therefore, the above-mentioned parameters corresponding to the conductive window group can be determined based on the requirements for the contact resistance between the positive connection electrode and the negative connection electrode of the back-contact battery and the conductive circuit layer, respectively, and the requirements for the size of the conductive window in the actual application scenario, and they will not be repeated here.

Exemplarily, the size of each conductive interconnect may be greater than or equal to 0.5 mm and less than or equal to 5 mm. For example, when the conductive interconnect is a cylindrical conductive interconnect, the diameter of the conductive interconnect may be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm or 5 mm.

Exemplarily, when the conductive interconnect further includes an interconnect, the length of the interconnect may be greater than or equal to 1 mm and less than or equal to 2 mm, and the length of the interconnect is the dimension in a direction parallel to the second direction. The width of the interconnect may be greater than or equal to 1 mm and less than or equal to 2 mm, and the width of the interconnect is the dimension in a direction parallel to the first direction. The height of the interconnect may be greater than or equal to 0.1 mm and less than or equal to 1 mm, and the height of the interconnect is the dimension in a direction orthogonal to the first direction and the second direction.

For example, as shown in FIGS. 4 to 6 , the difference between the lateral dimension of the portion of the conductive interconnect 8 at any position (height) along the first direction and the lateral dimension of the portion of the corresponding conductive window at the same position (height) along the first direction is greater than 0 and less than or equal to 3 mm. The difference in the lateral dimensions of the portions at the same position (height) along the first direction may be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm. In this case, the difference in the lateral dimensions of the portion of the conductive interconnect 8 at any position (height) along the first direction and the lateral dimensions of the portion of the corresponding conductive window at the same position (height) along the first direction is within the above range, which can prevent the position of the insulating material layer from being allowed to be offset relative to the back contact battery pack and the conductive circuit layer due to the small difference, and can further reduce the composite precision requirements between the insulating material layer and the conductive circuit layer while ensuring that the conductive interconnect 8 can have a large actual coupling area with the conductive circuit layer through the conductive window set in the insulating material layer; secondly, it can also prevent the conductive window from being large due to the large difference, which easily causes the back contact battery pack to be exposed at the conductive window through the conductive circuit layer. Leakage occurs, reducing the risk of short circuit.

The minimum distance between the conductive interconnect located on each positive connection electrode and the negative electrode in the same back-contact battery, and the minimum distance between the conductive interconnect located on each negative connection electrode and the positive electrode in the same back-contact battery can be determined based on the leakage requirements of the back-contact battery in the actual application scenario, etc., and are not specifically limited here.

For example, as shown in FIGS. 4 to 6 , in the same back-contact battery, the minimum spacing between the conductive interconnector 8 located on each positive connection electrode and the negative electrode 3 is greater than or equal to 0.2 mm and less than or equal to 1.5 mm. For example, in the same back-contact battery, the minimum spacing between the conductive interconnector 8 located on each positive connection electrode and the negative electrode 3 can be 0.2 mm, 0.5 mm, 1.0 mm or 1.5 mm. In this case, in the same back-contact battery, the minimum spacing between the conductive interconnector 8 located on each positive connection electrode and the negative electrode 3 is within the above range. Within the range, it can prevent leakage between the conductive interconnect 8 and the negative electrode 3 located on each positive connection electrode due to the small minimum spacing mentioned above, thereby reducing the risk of short circuit; secondly, it can also prevent the minimum spacing between each positive connection electrode and the negative electrode 3 in the same back contact battery from being large due to the large minimum spacing mentioned above, resulting in the inability to extract the carriers in time, thereby ensuring that the back contact battery has a high photoelectric conversion efficiency.

In a possible implementation, as shown in Figures 4 to 6, in the same back-contact battery, the minimum spacing between the conductive interconnector 8 located on each negative connection electrode and the positive electrode 2 is greater than or equal to 0.2 mm and less than or equal to 1.5 mm. The beneficial effects in this case can be referred to the beneficial effect analysis of the minimum spacing between the conductive interconnector 8 located on each positive connection electrode and the negative electrode 3 being greater than or equal to 0.2 mm and less than or equal to 1.5 mm in the same back-contact battery described above, and will not be repeated here.

For the above-mentioned insulating material layer, from the aspect of the arrangement of the conductive windows, the distribution of different conductive window groups set in the insulating material layer, and the distribution of different conductive windows in the same conductive window group can be determined according to the coupling position and coupling area of the positive connection electrode and the negative connection electrode included in the back contact battery and the conductive circuit layer in the actual application scenario.

For example: as shown in Figures 7 to 9, when a conductive interconnect group 7 is provided on the backlight surface of the back contact battery 1, if two conductive interconnect members 8 located at the same layer in two adjacent conductive interconnect groups 7 are aligned along a first direction, then as shown in Figures 1 and 3, two conductive windows 11 located at the same layer in two adjacent conductive window groups 10 may also be aligned along the first direction.

For another example, as shown in FIG. 10 , when a conductive interconnection group is provided on the backlight surface of the back contact cell, if two conductive interconnections 8 located at the same layer number in two adjacent conductive interconnection groups are staggered along the first direction, As shown in FIG. 2 , two conductive windows 11 located at the same layer in two adjacent conductive window groups 10 may also be staggered along the first direction.

From the perspective of morphology, half of the lateral dimension of the conductive window provided in the insulating material layer can be any value greater than or equal to 2.5 mm and less than the spacing between adjacent positive connection electrodes and negative connection electrodes in the same back contact battery. For example, when the size of the back contact battery is 182 mm, and the total number of positive connection electrodes and negative connection electrodes included in the back contact battery is 15, the spacing between adjacent positive connection electrodes and negative connection electrodes in the same back contact battery can be approximately 11.4 mm. In this case, half of the lateral dimension of the conductive window provided in the insulating material layer can be 2.5 mm, 3 mm, 5 mm, 7 mm, 9 mm or 11 mm, etc.

As for the shape of the conductive window, it can be a regular square, rectangle, circle or ellipse, or it can be a special shape as shown in FIG3 . In addition, as mentioned above, compared with the conductive window set in the existing insulating material layer, the size of the conductive window set in the insulating material layer in the present application is larger. At this time, in the case where the back contact battery is a main grid back contact battery, as shown in FIG5 and FIG6 , each conductive window can expose part of the opposite electrode in the projection area on the backlight surface. For example: as shown in FIG5 , if the first column of connecting electrodes is a positive connecting electrode and the second column of connecting electrodes is a negative connecting electrode, then each conductive window corresponding to the first column of positive connecting electrodes exposes part of the collector electrode 4 included in the negative electrode 3 in the projection area on the backlight surface.

In the above case, as shown in FIG. 11 and FIG. 12, an insulating spacer 12 is provided on the backlight surface of the back contact cell, and the insulating spacer 12 is used to connect the positive connection electrode included in the same back contact cell with the conductive circuit. The coupling between the layers is isolated from the negative electrode 3, and the coupling between the negative connection electrode and the conductive circuit layer is isolated from the positive electrode 2, further reducing the risk of leakage of the back contact battery pack through the conductive circuit layer when the lateral size of the conductive window becomes larger.

Specifically, the insulating isolation part can cover all areas on the backlight surface except the areas where the positive connection electrode and the negative connection electrode need to be coupled with the conductive circuit layer. Alternatively, the insulating isolation part can also be locally arranged near each coupling area according to the size of the conductive window and the distribution of the opposite-sex electrodes near each coupling area.

Exemplarily, as shown in FIG. 11 and FIG. 12, when the geometric center of the projection area (the area indicated by the circular dotted line in the figure) of each conductive window on the backlight surface coincides with the geometric center of the corresponding coupling point, the projection area is the target area. In the above case, a plurality of insulating isolation parts 12 extending along the first direction and spaced apart along the second direction are provided on the backlight surface of the back contact battery. Each insulating isolation part 12 includes a plurality of insulating isolation members 13 spaced apart along the first direction. Moreover, each insulating isolation member 13 corresponding to the positive connection electrode at least covers the portion of the negative electrode 3 exposed at the corresponding target area. Each insulating isolation member 13 corresponding to the negative connection electrode at least covers the portion of the positive electrode 2 exposed at the corresponding target area. In this case, in the actual manufacturing process, when the relative positions of the insulating material layer and the conductive circuit layer are not offset when they are compounded, the geometric center of the projection area of each conductive window on the backlight surface coincides with the geometric center of the corresponding coupling point. Based on this, when the geometric center of the projection area of each conductive window on the backlight surface coincides with the geometric center of the corresponding coupling point, the projection area is the target area. In this case, each insulating spacer 13 corresponding to the positive connection electrode at least covers the negative electrode 3 exposed to the corresponding On the portion at the target area, not only can the portion of the negative electrode 3 exposed at the conductive window corresponding to the positive connection electrode be covered by the insulating spacer 13 to prevent leakage, but also the amount of consumables used in the insulating spacer 12 can be reduced, which is beneficial to controlling the manufacturing cost of the photovoltaic module. Similarly, each insulating spacer 13 corresponding to the negative connection electrode at least covers the portion of the positive electrode 2 exposed at the corresponding target area, not only can the portion of the positive electrode 2 exposed at the conductive window corresponding to the negative connection electrode be covered by the insulating spacer 13 to prevent leakage, but also the amount of consumables used in the insulating spacer 12 can be reduced.

Each insulating spacer may just cover only the portion of the opposite-sex electrode exposed at the corresponding target area. In other words, each insulating spacer corresponding to the positive connection electrode only covers the portion of the negative electrode exposed at the corresponding target area, and each insulating spacer corresponding to the negative connection electrode only covers the portion of the positive electrode exposed at the corresponding target area.

Alternatively, the coverage area of each insulating spacer near the coupling area is larger than the range of the portion of the opposite-sex electrode exposed at the corresponding target area. In other words, the lateral dimension of the portion of each insulating spacer corresponding to the positive connecting electrode at any position (height) along the first direction is larger than the lateral dimension of the portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction. In this case, the amount (length) by which the lateral dimension of the portion of each insulating spacer corresponding to the positive connecting electrode at any position (height) along the first direction is larger than the lateral dimension of the portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction can be regarded as the margin allowed for the insulating material layer and the conductive circuit layer to be offset when they are compounded; when the insulating material layer and the conductive circuit layer are offset when they are compounded, the actual offset amount (length) is within this margin. Within the range, the collector electrode included in the negative electrode exposed at the conductive window can be covered by an insulating spacer, thereby increasing the conductive window while reducing the risk of leakage of the back contact battery pack through the conductive circuit layer.

Furthermore, the lateral dimension of the portion of each insulating spacer corresponding to the negative connection electrode at any position (height) along the first direction is greater than the lateral dimension of the portion of the collector electrode included in the positive electrode exposed in the corresponding target area at the same position (height) along the first direction. The beneficial effects in this case can be analyzed with reference to the beneficial effects of the lateral dimension of the portion of each insulating spacer corresponding to the positive connection electrode at any position (height) along the first direction being greater than the lateral dimension of the portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction, which will not be repeated here.

Specifically, the difference between the lateral dimensions of a portion of each insulating isolation member at any position (height) along the first direction and the lateral dimensions of a portion of the collecting electrode included in the anisotropic electrode exposed in the corresponding target area at the same position (height) along the first direction can be determined based on the actual application scenario and is not specifically limited here.

For example: the difference between the lateral dimensions of a portion of each insulating isolation member corresponding to the positive connecting electrode at any position (height) along the first direction and the lateral dimensions of a portion of the collecting electrode included in the negative electrode exposed in the corresponding target area at the same position (height) along the first direction is greater than or equal to 2 mm and less than or equal to 4 mm.

For example, each insulating spacer corresponding to the negative connection electrode is located at any position (high The difference between the lateral dimension of the portion at the same position (height) along the first direction and the lateral dimension of the portion of the collector electrode included in the positive electrode exposed in the corresponding target area is greater than or equal to 2 mm and less than or equal to 4 mm.

Alternatively, as shown in FIG4 , each conductive window does not expose the opposite electrode in the projection area on the backlight surface. For example, as shown in FIG4 , the positive connection electrodes and the negative connection electrodes are arranged from left to right and from small to large. If the first column of connection electrodes are positive connection electrodes and the second column of connection electrodes are negative connection electrodes, then the projection area on the backlight surface of each conductive window corresponding to the first column of positive connection electrodes does not expose the collector electrode 4 included in the negative electrode 3.

In the above case, as shown in FIG3 , the lateral dimension of the conductive window 11 corresponding to the positive connection electrode is smaller than the longitudinal dimension of the conductive window 11 , so that the coupling between the positive connection electrode and the conductive circuit layer and the collector electrode included in the negative electrode are separated by the insulating material layer 9 . The longitudinal dimension is the dimension in the direction parallel to the first direction. At this time, while at least the longitudinal dimension of the conductive window 11 corresponding to the positive connection electrode is enlarged, thereby increasing the allowance for the insulating material layer 9 to be offset relative to the back contact battery group and the conductive circuit layer along its own longitudinal dimension direction when the back contact battery group, the insulating material layer 9 and the conductive circuit layer are composited, because the collector electrode included in the same back contact battery extends along the second direction, it is also possible to provide a conductive window 11 with a smaller lateral dimension in the insulating material layer 9 to ensure that the insulating material layer 9 can separate the collector electrode included in the negative electrode near each conductive window 11 to prevent leakage. In addition, there is no need to additionally provide an insulating spacer 13 on the backlight surface of the back contact battery, thereby simplifying the manufacturing process of the back contact battery group.

Furthermore, as shown in FIG3 , the lateral dimension of the conductive window 11 corresponding to the negative connection electrode is smaller than the longitudinal dimension of the conductive window 11 , so that the coupling between the negative connection electrode and the conductive circuit layer and the collector electrode included in the positive electrode are isolated by the insulating material layer 9 . The longitudinal dimension is the dimension in the direction parallel to the first direction. The beneficial effects in this case can be analyzed with reference to the beneficial effects of the lateral dimension of the conductive window 11 corresponding to the positive connection electrode being smaller than the longitudinal dimension of the conductive window 11 as described above, and will not be repeated here.

The difference between the lateral dimension of the conductive window and its longitudinal dimension can be determined according to the range of the heterogeneous electrode exposed in the target area, and is not specifically limited here.

In addition, as for the material of the insulating material layer, it can be an insulating material such as IEP, EPE, polyimide (PI) and the like. Here, "IEP" is an insulating material with the following multilayer structure: polyolefin film (polyolefin film) + polyethylene terephthalate (PET) + polyolefin film, that is, it includes two polyolefin films and a PET layer located between the two polyolefin films, and the PET layer can be combined with each polyolefin film by an adhesive (such as glue); "EPE" is an insulating material with the following multilayer structure: ethylene-vinyl acetate copolymer (EVA) + POE + EVA, that is, it includes two EVA layers and a POE layer located between the two EVA layers, and the POE layer can be combined with each EVA layer by an adhesive (such as glue).

For the above-mentioned conductive circuit layer, the pattern set on the conductive circuit layer can be determined according to the actual application scenario, as long as it can make different back contact battery strings included in the back contact battery pack connected in parallel through the conductive circuit layer, and make different back contact batteries included in the same back contact battery string connected in series through the conductive circuit layer. Both are acceptable.

In addition, the conductive circuit layer can be a conductive foil with a small thickness and provided with a pattern, such as aluminum foil, copper foil, copper-aluminum foil, copper foil plated with aluminum, copper foil plated with nickel, copper foil plated with tin, aluminum foil plated with copper, aluminum foil plated with tin, aluminum foil plated with nickel, etc. Alternatively, it can also be a conductive plate with a large thickness, such as an aluminum plate or a copper plate, etc. Of course, the conductive circuit layer can also include a composite layer of a conductive material and a non-conductive material.

In addition, the photovoltaic module provided in the embodiment of the present application may also include a backplane located on the side of the conductive circuit layer away from the insulating material layer, and a first encapsulation film located between the backplane and the conductive circuit layer. The material of the backplane may be TPC, PET, TPT, CPC or other materials to prevent the conductive circuit layer from reacting in the external environment and extend the service life of the photovoltaic module. Here, "TPC" is an insulating material with the following multi-layer structure: polytetrafluoroethylene (PTFE) + PET + coating, that is, including a PTFE layer, a PET layer and a coating located on the side of the PET layer away from the PTFE layer, and different layers can be combined by an adhesive (such as glue); "TPT" is an insulating material with the following multi-layer structure: PTFE + PET + PTFE, that is, including two PTFE layers and a PET layer located between the two PTFE layers, and the PET layer and each PTFE layer can be combined by an adhesive (such as glue); "CPC" is an insulating material with the following multi-layer structure: coating + PET + coating, that is, including a PET layer and two coatings located on two opposite sides of the PET layer, and different layers can be combined by an adhesive (such as glue). The material of the first packaging film can be POE, EVA, polyvinyl butyral (PVB, polyvinyl butyral) or other materials.

Specifically, the conductive circuit layer, the first packaging film and the back plate may be provided with holes to facilitate The location, quantity and size of the holes can be set according to the actual application scenario and are not specifically limited here.

Secondly, the photovoltaic module provided in the embodiment of the present application may also include a second encapsulation film disposed on the side of the back contact battery group away from the insulating material layer, and a transparent cover plate located on the second encapsulation film to protect the back contact battery and extend the service life of the photovoltaic module. The material of the second encapsulation film may refer to the material of the first encapsulation film described above. As for the transparent cover plate, the material of the transparent cover plate may include at least one of tempered glass, high-transmittance plastic and silicone rubber.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the attached claims.

Claims (11)

A photovoltaic module, characterized by comprising: a conductive back plate, and a back contact battery group arranged on the conductive back plate; The conductive backplane comprises a conductive circuit layer and an insulating material layer between the conductive circuit layer and the back contact battery group; the insulating material layer is provided with a plurality of conductive window groups extending along a first direction and spaced apart along a second direction, each of the conductive window groups comprises a plurality of conductive windows spaced apart along the first direction, and the bottom of each conductive window exposes the conductive circuit layer; the first direction is different from the second direction; The back-contact battery group includes a plurality of back-contact battery strings extending along a third direction and spaced apart along a fourth direction, wherein the third direction is different from the fourth direction; each of the back-contact battery strings includes a plurality of back-contact batteries spaced apart along the third direction; the positive connection electrode and the negative connection electrode included in each of the back-contact batteries are respectively coupled with the portion of the conductive circuit layer exposed at the corresponding conductive window, so that the plurality of back-contact battery strings are connected in parallel through the conductive circuit layer, and the plurality of back-contact batteries included in each of the back-contact battery strings are connected in series through the conductive circuit layer; one-half of the maximum lateral dimension of the conductive window is greater than 2.5 mm and less than the spacing between adjacent positive connection electrodes and negative connection electrodes in the same back-contact battery, and the lateral dimension is the dimension in a direction parallel to the second direction. The photovoltaic module according to claim 1, characterized in that the back contact cell has a backlight A plurality of conductive interconnection groups extending along the first direction and spaced apart along the second direction are arranged on the surface; each of the conductive interconnection groups is located on the corresponding positive connection electrode or the negative connection electrode, and each of the conductive interconnection groups includes a plurality of conductive interconnection members spaced apart along the first direction; The positive connection electrode and the negative connection electrode are respectively coupled to the conductive circuit layer through the multiple conductive interconnects included in the corresponding conductive interconnect group; the lateral dimensions of the portion of the conductive interconnect at any position along the first direction are smaller than the lateral dimensions of the portion of the corresponding conductive window at the same position along the first direction. The photovoltaic module according to claim 2 is characterized in that the difference between the lateral dimension of a portion of the conductive interconnect at any position along the first direction and the lateral dimension of a portion of the corresponding conductive window at the same position along the first direction is greater than 0 and less than or equal to 3 mm. The photovoltaic module according to claim 2, characterized in that, in the same back contact cell, the minimum spacing between the conductive interconnect located on each positive connection electrode and the negative electrode including the corresponding negative connection electrode is greater than or equal to 0.2 mm and less than or equal to 1.5 mm; and/or, In the same back-contact battery, the minimum distance between the conductive interconnector located on each negative connection electrode and the positive electrode including the corresponding positive connection electrode is greater than or equal to 0.2 mm and less than or equal to 1.5 mm. The photovoltaic module according to claim 1, characterized in that each of the conductive window groups defines a plurality of layers spaced apart along the first direction, each of the layers is sorted according to its position in the first direction and is assigned a number of layers consistent with its sorting, and each of the conductive window groups includes a plurality of conductive windows each located in a different layer of the plurality of layers defined by the conductive window group, wherein adjacent In the two conductive window groups, the two conductive windows located at the same number of layers are staggered along the first direction; and in the same conductive window group, the conductive windows located at different numbers of layers are spaced apart along the first direction. The photovoltaic module according to any one of claims 1 to 5, characterized in that the positive electrode and the negative electrode of the back contact cell both include a plurality of bus electrodes and a plurality of collector electrodes; wherein, In each of the back-contact cells, the bus electrodes included in the positive electrode and the negative electrode extend along the first direction and are alternately spaced along the second direction; each of the bus electrodes is connected to a collector electrode with the same polarity as itself; the collector electrodes included in the positive electrode and the negative electrode extend along the second direction and are alternately spaced along the first direction; each of the collector electrodes includes a plurality of collector electrode segments spaced along the second direction, and two adjacent collector electrode segments included in the same collector electrode are used to separate the bus electrode with the opposite polarity to itself; The positive connection electrode is a bus electrode included in the positive electrode, and the negative connection electrode is a bus electrode included in the negative electrode. The photovoltaic module according to claim 6 is characterized in that one-half of the maximum lateral dimension of the conductive window is greater than the spacing between each collecting electrode segment and the adjacent bus electrode with opposite polarity to itself, and an insulating isolation portion is provided on the backlight surface of the back contact battery, and the insulating isolation portion is used to isolate the coupling point between the positive connecting electrode and the conductive circuit layer included in the same back contact battery from the negative electrode of the back contact battery, and to isolate the coupling point between the negative connecting electrode of the back contact battery and the conductive circuit layer from the positive electrode of the back contact battery. The photovoltaic module according to claim 7, characterized in that when the geometric center of the projection area of each of the conductive windows on the backlight surface coincides with the geometric center of the corresponding coupling point, the projection area is the target area; The backlight surface is provided with a plurality of insulating isolation parts extending along the first direction and spaced apart along the second direction; each of the insulating isolation parts includes a plurality of insulating isolation pieces spaced apart along the first direction; Each of the insulating spacers corresponding to the positive connecting electrode at least covers the portion of the negative electrode exposed at the corresponding target area; each of the insulating spacers corresponding to the negative connecting electrode at least covers the portion of the positive electrode exposed at the corresponding target area. The photovoltaic module according to claim 8, characterized in that the lateral size of the portion of each of the insulating spacers corresponding to the positive connecting electrode at any position along the first direction is larger than the lateral size of the portion of the collector electrode included in the negative electrode exposed in the corresponding target area at the same position along the first direction; and/or, The lateral dimension of a portion of each of the insulating spacers corresponding to the negative connecting electrode at any position along the first direction is greater than the lateral dimension of a portion of a collector electrode included in the positive electrode exposed in the corresponding target area at the same position along the first direction. The photovoltaic module according to claim 6, characterized in that the lateral dimension of the conductive window corresponding to the positive connecting electrode is smaller than the longitudinal dimension of the conductive window, so that the coupling point between the positive connecting electrode and the conductive circuit layer and the collector included in the negative electrode are connected through the insulating material layer. The electrodes are separated; the longitudinal dimension is the dimension in a direction parallel to the first direction; and/or, The lateral dimension of the conductive window corresponding to the negative connecting electrode is smaller than the longitudinal dimension of the conductive window, so as to isolate the coupling between the negative connecting electrode and the conductive circuit layer and the collector electrode included in the positive electrode through the insulating material layer; the longitudinal dimension is the dimension in the direction parallel to the first direction. The photovoltaic assembly according to any one of claims 1 to 5, characterized in that the first direction is parallel to the third direction, and the second direction is parallel to the fourth direction; or, The first direction is parallel to the fourth direction, and the second direction is parallel to the third direction.