Back contact battery, solar cell structure, and solar cell module

Abstract

This application discloses a back-contact battery, solar cell structure, and solar cell module, which relate to the technical field of solar cells and are used to suppress current mismatches between different bus electrodes on a positive electrode and different bus electrodes on a negative electrode. The back-contact battery includes a battery body and a positive electrode and a negative electrode formed on a non-light-receiving surface of the battery body. Each of the positive electrode and the negative electrode includes a plurality of current collecting electrodes, a plurality of bus electrodes, and at least one connection electrode. At least one current collecting electrode included in the positive electrode and at least one current collecting electrode included in the negative electrode are both continuous current collecting electrodes. Each bus electrode includes a plurality of bus electrode segments spaced apart in a second direction, and two adjacent bus electrode segments on the same bus electrode are separated by a space from each collecting electrode of the opposite polarity. Each connection electrode is connected to all collecting electrodes of the same polarity as itself and is insulated from each collecting electrode of the opposite polarity.

Description

Technical Field

[0005] , , ,

[0006] ,

[0001] This application relates to the technical field of solar cells, and particularly to back contact cells, solar cell structures, and solar cell modules.

[0002] (Cross-reference to related applications) This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on November 7, 2022, with the application number 202222957031.9 and the invention title "Back Contact Cell, Solar Cell Structure, and Solar Cell Module", and the entire content thereof is incorporated herein by reference.

Background Art

[0003] A back contact cell is a solar cell in which both the emitter and the metal contact are on the back surface of the cell, and the front surface is not shielded by a metal electrode. Since the back contact cell has a higher short-circuit current and photoelectric conversion efficiency than a solar cell with a shielded front surface, it is currently one of the technical trends for realizing high-efficiency crystalline silicon cells.

[0004] However, there is current mismatch between different bus electrodes in the positive electrode and between different bus electrodes in the negative electrode included in the conventional back contact cell, which is disadvantageous for improving the electrical performance of the back contact cell.

Summary of the Invention

[0005] This application is used to suppress the current mismatch existing between different bus electrodes in the positive electrode and between different bus electrodes in the negative electrode included in the back contact cell, and aims to provide a back contact cell, a solar cell structure, and a solar cell module that are advantageous for improving the electrical performance of the back contact cell.

[0006] In a first aspect, the present application provides a back-contact battery. The back-contact battery includes a battery body and a positive electrode and a negative electrode formed on a non-light-receiving surface of the battery body. Both the positive electrode and the negative electrode include a plurality of current-collecting electrodes, a plurality of bus electrodes, and at least one connecting electrode.

[0007] The current collector electrodes included in the positive electrode and the current collector electrodes included in the negative electrode both extend in a first direction and are arranged alternately at intervals in a second direction. The first direction is different from the second direction. At least one current collector electrode included in the positive electrode and at least one current collector electrode included in the negative electrode are both continuous current collector electrodes. The bus electrodes included in the positive electrode and the bus electrodes included in the negative electrode both extend in a second direction and are arranged alternately at intervals in the first direction. Each bus electrode is connected to a current collector electrode of the same polarity as itself, and each bus electrode includes multiple bus electrode segments distributed at intervals in the second direction, with two adjacent bus electrode segments on the same bus electrode separated from the respective current collector electrodes of opposite polarity by the spacing. Each connecting electrode is located outside in the first direction of all bus electrodes included in the positive electrode and the negative electrode. Each connecting electrode is connected to all current collector electrodes of the same polarity as itself and is insulated from the current collector electrodes of opposite polarity as itself.

[0008] When the above technical solution is adopted, in the back-contact battery provided by this application, each bus electrode includes a plurality of bus electrode segments distributed at intervals in a second direction, and two adjacent bus electrode segments on the same bus electrode are spaced apart from the current collector electrodes of opposite polarity. In this case, a short-circuit problem does not occur even if insulating material is not placed between each bus electrode and the current collector electrode of opposite polarity, thus reducing the amount of insulating material used and lowering the manufacturing cost of the back-contact battery.

[0009] Furthermore, different bus electrode segments included in each bus electrode are connected to corresponding current collector electrodes of the same polarity, thereby concentrating the carriers collected at the corresponding positions on the current collector electrodes. Also, if at least one current collector electrode included in the positive electrode is a continuous current collector electrode, the continuous current collector electrode included in the positive electrode can equalize the currents of different bus electrode segments connected via the continuous current collector electrode by connecting bus electrode segments belonging to different bus electrodes in the positive electrode. Next, the connecting electrode included in the positive electrode is connected to all current collector electrodes included in the positive electrode, and by connecting the current collector electrodes included in the positive electrode, it further connects different bus electrode segments connected to the current collector electrodes included in the positive electrode. This is advantageous in further suppressing current mismatch between different bus electrodes included in the positive electrode, and in connecting all bus electrode segments belonging to the same bus electrode via a connecting electrode, thereby preventing some bus electrode segments included in a bus electrode from becoming unable to connect to the string interconnect member due to bias of the string interconnect member welded to one of the bus electrodes included in the positive electrode, and is advantageous in ensuring that carriers collected by each bus electrode segment included in the bus electrode can all be drawn out via the string interconnect member, and is also advantageous in improving the photoelectric conversion efficiency of the back contact battery. Similarly, the negative electrode in this application also has the beneficial effects of the positive electrode described above, and a detailed explanation is omitted here.

[0010] In one possible implementation, the distance between two adjacent bus electrode segments in the same bus electrode in the second direction is 0.4 mm to 2 mm. In this case, the size of the distance between two adjacent bus electrode segments in the same bus electrode in the second direction is appropriate, preventing the bus electrode segment from being connected to a current collector electrode of opposite polarity and causing a short circuit problem due to a small distance, and ensuring that each bus electrode segment can be separated from a current collector electrode of opposite polarity by the distance. Furthermore, a larger distance reduces the length of each bus electrode segment in the second direction, preventing it from affecting the concentration of carriers generated by photon absorption at the corresponding position of the battery body onto the bus electrode segment, and ensuring that each bus electrode segment has high carrier concentration capability, thereby further improving the electrical performance of the back contact battery.

[0011] In one possible implementation, each of the above-mentioned connecting electrodes is located at the first-direction end of all current-collecting electrodes included in the positive and negative electrodes. In this case, each connecting electrode may be located at the first-direction edge of the battery body, which is advantageous in increasing the distance between each connecting electrode and the bus electrode of opposite polarity, thereby preventing short circuits.

[0012] In one possible implementation, all current-collecting electrodes included in the positive and negative electrodes have their ends in the same plane in the first direction. In this case, all current-collecting electrodes included in the positive and negative electrodes can be regularly distributed on the non-photosensitive surface of the electrode body in the first direction, which is advantageous for effectively collecting carriers generated by photon absorption in each part of the battery body in the first direction by each current-collecting electrode, and is also advantageous for improving the electrical performance of the back-contact battery.

[0013] In one possible implementation, at least one connecting electrode included in the positive electrode is located first outside in the first direction of all bus electrodes included in the positive and negative electrodes. At least one connecting electrode included in the negative electrode is located second outside in the first direction of all bus electrodes included in the positive and negative electrodes. The second outside and the first outside are provided opposite each other.

[0014] When the above technical solution is adopted, all connecting electrodes included in the positive electrode are similarly located on the first outer side in the first direction of all bus electrodes included in the back contact battery. Similarly, all connecting electrodes included in the negative electrode are similarly located on the second outer side in the first direction of all bus electrodes included in the back contact battery. Furthermore, by providing the first outer side and the second outer side opposite each other, it is possible to prevent short-circuit problems from occurring when connecting electrodes with opposite polarities are located on the same outer side, thereby ensuring that the back contact battery has stable electrical performance.

[0015] In one possible implementation, each current collector electrode has a gap extending in a first direction from the connecting electrode of opposite polarity to itself. In this case, each current collector electrode can be separated from the connecting electrode of opposite polarity to itself by the gap extending in the first direction, and as a result, short-circuit problems do not occur even if insulating material is not placed between each current collector electrode and the connecting electrode of opposite polarity to itself, thus further reducing the amount of insulating material used and lowering the manufacturing cost of back contact batteries.

[0016] In one possible implementation, the multiple bus electrode segments included in the same bus electrode are distributed at equal intervals in the second direction. In this case, it is advantageous to uniformly distribute the multiple bus electrodes included in the positive and negative electrodes to the non-photosensitive surface of the battery body, and furthermore, the distance between each portion of the battery body parallel to the non-photosensitive surface and the corresponding bus electrode can be made approximately equal. This is advantageous because carriers generated by photon absorption in each portion of the battery body are collected by the corresponding current collector electrode in a timely manner and concentrated by the corresponding bus electrode in a timely manner, thereby reducing the carrier recombination rate and further improving the photoelectric conversion efficiency of the back-contact battery.

[0017] In one possible implementation, the lengths of the different bus electrode segments contained within the same bus electrode are the same, and the length direction of the bus electrode segments is parallel to the second direction. The beneficial effects in this case may be discussed by referring to the analysis of the beneficial effects of having multiple bus electrode segments contained within the same bus electrode distributed at equal intervals in the second direction, as described above, and a detailed explanation is omitted here.

[0018] In one possible implementation, the number of bus electrode segments contained in the same but differently polarized bus electrodes is the same. The beneficial effects in this case can be seen by referring to the analysis of the beneficial effects of having multiple bus electrode segments contained in the same bus electrode distributed at equal intervals in the second direction, as described above, and a detailed explanation is omitted here.

[0019] In one possible implementation, bus electrode segments of the same polarity but in the same order are aligned at both ends in the same plane. Bus electrode segments of the same bus electrode but in a different order are spaced apart in a second direction.

[0020] When the above technical solution is adopted, bus electrode segments of the same order in bus electrodes of the same polarity and different polarities have both ends on the same plane in the same direction, and the spacing between segments of the same order in bus electrodes of the same polarity and different polarities can extend along that direction, which is advantageous for the current collector electrode to become a linear current collector electrode that extends in a single straight direction, and is advantageous for simplifying the structure of the current collector electrodes included in the positive and negative electrodes.

[0021] In one possible implementation, the same order of bus electrode segments in the opposite polarity bus electrodes are arranged alternately at both ends in the second direction. Different order of bus electrode segments in the same bus electrode are distributed at intervals in the second direction.

[0022] When the above technical solution is adopted, the heights in the second direction of bus electrode segments of the same order in bus electrodes with opposite polarities are different. Based on this, if other elements are the same, the ends of bus electrode segments of the same order in bus electrodes with opposite polarities are arranged alternately in the second direction. This makes it possible to increase the spacing between two adjacent bus electrode segments included in the same bus electrode, further preventing short circuits caused by the connection between each bus electrode segment and a current collector electrode of the opposite polarity, and improving the electrical stability of the back contact battery.

[0023] In one possible implementation, the back contact battery further includes welds, each weld being connected to a corresponding bus electrode.

[0024] In one possible implementation, of all welds included in a back-contact battery, at least a portion of the welds located between two adjacent bus electrode segments included in the same bus electrode are Class 1 welds, and the remaining welds are Class 2 welds. Of all current collector electrodes included in the positive and negative electrodes, at least a portion of the current collector electrodes that are at the same height as the Class 1 welds in a second direction are Class 1 current collector electrodes, and the remaining current collector electrodes are Class 2 current collector electrodes. Each bus electrode has the same polarity as the welds provided on itself. Each Class 1 current collector electrode includes multiple current collector electrode segments distributed at intervals in a first direction, and two adjacent current collector electrode segments included in the same Class 1 current collector electrode are spaced apart from the Class 1 welds with opposite polarity to itself. In this case, short-circuit problems do not occur even if insulating material is not placed between each Class 1 current collector electrode and the welds with opposite polarity to itself, thus further reducing the amount of insulating material used and lowering the manufacturing cost of the back-contact battery.

[0025] In a second aspect, the present invention further provides a solar cell structure comprising an insulating material and a back contact cell provided in the first aspect and various realizations thereof. The insulating material covers the space between at least two adjacent bus electrode segments contained in each bus electrode.

[0026] In one possible implementation, the width of the insulating material is greater than the width of the bus electrode in the first direction, but less than a predetermined width. The predetermined width is 1.5 mm to 10 mm. In this case, the width of the insulating material in the first direction is appropriate, preventing an increase in the amount of insulating material used due to a larger width, which is advantageous in reducing the manufacturing cost of back contact batteries. Furthermore, the small width of the insulating material prevents the need to strictly specify the placement of interconnecting members within the string when connecting different back contact batteries, which is advantageous in reducing the difficulty of welding when connecting at least two back contact batteries.

[0027] In one possible implementation, when the back contact battery includes a welding part and each welding part is connected to a corresponding bus electrode, the solar cell structure further includes a conductive adhesive. The conductive adhesive is provided at at least one welding part.

[0028] When the above technical solution is adopted, within a predetermined range, the greater the thickness of the insulating material, the higher the insulating effect of the insulating material. When the thickness of the insulating material is relatively large, the top height of the insulating material may be greater than the top height of the welding part. Based on this, by providing a conductive adhesive at each welding part, the top height of the structure composed of the conductive adhesive and the welding part can be made not less than the top height of the insulating material, ensuring that the interconnecting member within the string can be connected to the corresponding welding part.

[0029] In a third aspect, the present application further provides a solar cell module. The solar cell module includes the back contact battery provided by the first aspect and its various implementations, or the solar cell structure provided by the second aspect and its various implementations.

[0030] For the beneficial effects of the second aspect, the third aspect and their various implementations in the present application, reference may be made to the analysis of the beneficial effects in the first aspect and its various implementations, and detailed description is omitted here.

[0031] As described above, the technical solution of the present invention has been briefly described. In order to understand the technical means of the present invention more clearly and be able to implement it based on the content of the specification, and to make the above and other objects, features and advantages of the present invention more understandable, specific embodiments of the present invention are given below.

Brief Description of the Drawings

[0032] To more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the drawings necessary for describing the embodiments or the prior art will be briefly described below. Naturally, the drawings described below are only a part of the embodiments of the present invention, and those skilled in the art will be able to conceive of other drawings based on these drawings without requiring any creative effort. [Figure 1] This is a schematic diagram of the structure of the positive and negative electrodes of a conventional back-contact battery. [Figure 2] (1) and (2) are schematic diagrams of two types of battery body structures provided by embodiments of the present invention. [Figure 3] This is a schematic diagram of the structure of a first type of back-contact battery provided by an embodiment of the present invention. [Figure 4] This is a schematic diagram of a second type of structure of a back-contact battery provided by an embodiment of the present invention. [Figure 5] This is a schematic diagram of a third type of structure of a back-contact battery provided by an embodiment of the present invention. [Figure 6] (1) is an enlarged view of the positional relationship between the current collector electrode and the bus electrode in an embodiment of the present application, where the heights in the second direction of the same order of bus electrode segments in bus electrodes with opposite polarities are partially the same, and (2) is an enlarged view of the positional relationship between the current collector electrode and the bus electrode in an embodiment of the present application, where the bus electrode segments in the second direction of the same order of bus electrodes with opposite polarities are arranged alternately. [Figure 7] This is a schematic diagram of a fourth type of structure of a back-contact battery provided by an embodiment of the present invention. [Figure 8] This is a schematic diagram of a fifth type of structure of a back-contact battery provided by the embodiment of the present invention. [Figure 9] This is a schematic diagram of a solar cell structure provided by an embodiment of the present invention. [Modes for carrying out the invention]

[0033] To further clarify the object, technical solution, and advantages of the embodiments of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments. Naturally, the embodiments described are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art without requiring any creative effort based on the embodiments of the present invention are all within the scope of the protection of the present invention.

[0034] To make the technical problems, technical means, and beneficial effects that this application aims to solve clearer and easier to understand, the application will be described in more detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are merely for interpretation purposes and are not intended to limit the application.

[0035] When an element is described as being "fixed to" or "installed" on another element, it is necessary to explain that it may be directly attached to the other element or indirectly attached to it. When an element is described as being "connected" to another element, it may be directly connected to the other element or indirectly connected to it.

[0036] Furthermore, the terms "first" and "second" are merely for explanatory purposes and should not be understood as explicitly or implicitly indicating relative importance or the number of technical features being described. Accordingly, features designated as "first" and "second" may explicitly or implicitly include one or more such features. In the description of this application, unless explicitly and specifically limited, "multiple" means two or more. Unless explicitly and specifically limited, "several" means one or more.

[0037] In the description of this application, it should be understood that the directions or positional relationships indicated by terms such as "up," "down," "front," "back," "left," and "right" are based on the drawings and are merely for the purpose of easily explaining this application and simplifying the description. It does not explicitly or implicitly suggest that the described devices or elements necessarily have a specific direction or are constructed or operated in a specific direction, and therefore should not be understood as limiting this application.

[0038] In the description of this application, unless otherwise explicitly defined or limited, the terms "attach," "connect," and "join" should be understood in a broad sense. For example, a connection may be fixed, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, or indirectly connected via an intermediate medium, or it may refer to internal communication between two elements or an interaction between two elements. A person skilled in the art will understand the specific meaning of the above terms in this application depending on the specific situation.

[0039] Currently, solar cells are gaining widespread use as a new energy alternative. A solar cell is a device that converts sunlight energy into electrical energy. Specifically, solar cells utilize the principle of photovoltaic energy to generate carriers, which are then extracted by electrodes, thus making them advantageous for the efficient use of electrical energy.

[0040] When both the positive and negative electrodes in a solar cell are located on the back surface of the solar cell, the solar cell becomes a back-contact battery. Conventional back-contact batteries include metal wrap-through (MWT) batteries and interdigitated back-contact (IBC) batteries. Of these, the IBC battery is characterized by having a higher short-circuit current Isc because both the emitter and metal contacts are on the back surface of the battery, and there is no shielding effect from the metal electrodes on the front surface. In addition, the curve factor FF can be improved by allowing a wide metal grid on the back surface of the IBC battery to reduce the series connection resistance Rs. Furthermore, batteries with an unshielded surface not only have high conversion efficiency but also a better appearance. In addition, since the assembly of full back electrodes is easier, IBC batteries are currently one of the technological directions for realizing high-efficiency crystalline silicon batteries.

[0041] In the actual manufacturing process, as shown in Figure 1, both the positive electrode 2 and the negative electrode 3 included in the IBC battery are formed on the non-light-receiving surface of the battery body 1. Both the positive electrode 2 and the negative electrode 3 include multiple current collector electrodes 4 and multiple bus electrodes 5. The multiple current collector electrodes 4 included in the positive electrode 2 and the negative electrode 3 extend in a first direction and are arranged alternately at intervals in a second direction. The multiple bus electrodes 5 included in the positive electrode 2 and the negative electrode 3 extend in a second direction and are distributed alternately at intervals in the first direction, where the first direction is different from the second direction. Each current collector electrode 4 is connected to a bus electrode 5 with the same polarity, and each current collector electrode 4 includes multiple current collector electrode segments 13 distributed at intervals in the first direction. Two adjacent current collector electrode segments 13 included in the same current collector electrode 4 are separated from the respective bus electrodes 5 with opposite polarity due to the spacing, preventing short circuits of the back contact battery caused by the connection of the positive electrode and the negative electrode 3.

[0042] However, as shown in Figure 1, different current collector segments 13 within the same current collector electrode 4 are insulated from each other, and each current collector segment 13 is used to collect carriers generated at the corresponding location on the battery body 1. Furthermore, different current collector segments 13 are connected to different bus electrodes 5 within the positive electrode 2, and different current collector segments 13 are connected to different bus electrodes 5 within the corresponding negative electrode 3. Based on this, when the back-contact battery is operating, the concentration of carriers generated at different locations on the battery body 1 may differ, which may result in different currents being collected by each current collector segment 13. In addition, the currents concentrated on the different bus electrodes 5 connected to the different current collector segments 13 on the positive electrode 2 will also differ, meaning that a current mismatch problem exists between the different bus electrodes 5 on the positive electrode 2. Similarly, a current mismatch problem also exists between the different bus electrodes 5 on the negative electrode 3, which is detrimental to improving the electrical performance of the back-contact battery.

[0043] To solve the above technical problems, in the first embodiment, the present invention provides a back-contact battery. As shown in Figures 3 to 5, the back-contact battery includes a battery body 1 and a positive electrode 2 and a negative electrode 3 formed on the non-light-receiving surface of the battery body 1. Both the positive electrode 2 and the negative electrode 3 include a plurality of current-collecting electrodes 4, a plurality of bus electrodes 5, and at least one connecting electrode 6.

[0044] As shown in Figures 3 to 5, the current collector electrodes 4 included in the positive electrode 2 and the current collector electrodes 4 included in the negative electrode 3 both extend in a first direction and are arranged alternately at intervals in a second direction. The first direction is different from the second direction. At least one current collector electrode 4 included in the positive electrode 2 and at least one current collector electrode 4 included in the negative electrode 3 are both continuous current collector electrodes. The bus electrodes 5 included in the positive electrode 2 and the bus electrodes 5 included in the negative electrode 3 both extend in a second direction and are arranged alternately at intervals in the first direction. Each bus electrode 5 is connected to a current collector electrode 4 of the same polarity as itself, and each bus electrode 5 includes a plurality of bus electrode segments 7 distributed at intervals in the second direction, and two adjacent bus electrode segments 7 on the same bus electrode 5 are spaced apart from the respective current collector electrodes 4 of opposite polarity to themselves by the spacing. Each connecting electrode 6 is located outside in the first direction of all the bus electrodes 5 included in the positive electrode 2 and the negative electrode 3. Each connecting electrode 6 is connected to all current collecting electrodes 4 of the same polarity as itself, and is insulated from itself by current collecting electrodes 4 of the opposite polarity.

[0045] Specifically, the specific structure and materials of the battery body described above can be set according to the actual application scenario and are not specifically limited here. For example, the battery body may include a semiconductor substrate, a P-type doped semiconductor layer, and an N-type doped semiconductor layer. Here, the material of the semiconductor substrate may be a semiconductor material such as silicon, germanium silicon, or gallium arsenide. The semiconductor substrate has a first surface and a second surface facing each other. The second surface corresponds to the non-light-receiving surface of the battery body. The second surface has a first region and a second region that are alternately provided in the first direction in a direction parallel to the second surface. The length extension direction of both the first region and the second region is parallel to the second direction. The P-type doped semiconductor layer is formed on or within the first region. The N-type doped semiconductor layer is formed on or within the second region. The doping concentration of impurities in the P-type doped semiconductor layer and the N-type doped semiconductor layer can be set according to the actual application scenario, as long as it is applicable to the back-contact battery provided by the embodiment of this application.

[0046] Furthermore, as shown in Figure 2(1), the battery body 1 may be a battery body with chamfered edges. Alternatively, as shown in Figure 2(2), the battery body 1 may be a battery body that is not further chamfered.

[0047] Regarding the positive and negative electrodes, as shown in Figures 3 to 5, the current collector electrode 4 formed on the corresponding P-type doped semiconductor layer is the current collector electrode 4 included in the positive electrode 2 and is used to collect holes transmitted from the P-type doped semiconductor layer. Furthermore, the bus electrode 5 connected to the current collector electrode 4 included in the positive electrode 2 is the bus electrode 5 included in the positive electrode 2. Conversely, the current collector electrode 4 formed on the corresponding N-type doped semiconductor layer is the current collector electrode 4 included in the negative electrode 3 and is used to collect electrons transmitted from the N-type doped semiconductor layer. Furthermore, the bus electrode 5 connected to the current collector electrode 4 included in the negative electrode 3 is the bus electrode 5 included in the negative electrode 3.

[0048] To make it clear, one current collector electrode in the positive electrode has the opposite polarity to one current collector electrode in the negative electrode (or one bus electrode and one connecting electrode in the negative electrode) and the same polarity to another current collector electrode in the positive electrode (or one bus electrode and one connecting electrode in the positive electrode). Similarly, one bus electrode in the positive electrode has the opposite polarity to one current collector electrode in the negative electrode (or one bus electrode and one connecting electrode in the negative electrode) and the same polarity to another bus electrode in the positive electrode (or one current collector electrode and one connecting electrode in the positive electrode). One connecting electrode in the positive electrode has the opposite polarity to one current collector electrode in the negative electrode (or one bus electrode and one connecting electrode in the negative electrode) and the same polarity to another bus electrode in the positive electrode (or one current collector electrode and one connecting electrode in the positive electrode). Accordingly, the situation of electrodes with the same or opposite polarity corresponding to the current collector electrodes, bus electrodes, and connecting electrodes in the negative electrode may be described in the preceding paragraph, and a detailed explanation is omitted here.

[0049] Furthermore, the number and specifications of current collector electrodes included in the positive and negative electrodes, and the size of the second-direction spacing between the current collector electrodes included in the positive electrode and the adjacent current collector electrodes included in the negative electrode, can be set according to the actual application scenario, as long as they are applicable to the back-contact battery provided by the embodiment of this application. Specifically, the number of current collector electrodes included in the positive and negative electrodes may be the same or different. The second-direction spacing between the current collector electrodes included in the positive electrode and the adjacent current collector electrodes included in the negative electrode may be 1 mm to 2 mm. Of course, the above spacing may be set to other appropriate values ​​according to the requirements of the actual application scenario. Next, as shown in Figures 3 to 5, all current collector electrodes 4 included in the positive electrode 2 and the negative electrode 3 may be continuous current collector electrodes. These continuous current collector electrodes are current collector electrodes without interruption. Alternatively, as shown in Figures 7 and 8, in both the positive electrode 2 and the negative electrode 3, some of the current collector electrodes 4 are continuous current collector electrodes, and the remaining current collector electrodes 4 are discontinuous current collector electrodes with interruptions. In this case, the number of continuous and discontinuous current-collecting electrodes, and the number and location of interruptions in the discontinuous current-collecting electrodes, for the positive electrode 2 and the negative electrode 3 can be set according to the actual application scenario, as long as it is applicable to the back-contact battery provided by the embodiment of this application.

[0050] The number and specifications of the bus electrodes included in the positive and negative electrodes, and the size of the spacing in the first direction between the bus electrodes included in the positive electrode and the adjacent bus electrodes included in the negative electrode, can be set according to the actual application scenario, as long as they are applicable to the back-contact battery provided by the embodiment of this application. For example, the total number of bus electrodes included in the positive and negative electrodes described above may be 6 to 24. In actual applications, the number of bus electrodes included in the positive and negative electrodes may be the same or different.

[0051] The current collector electrodes included in the positive and negative electrodes described above may be linear, wavy, or bent-wire current collectors, and the specific shapes of the current collector electrodes included in the positive and negative electrodes can be set according to the actual application scenario and are not specifically limited here. Furthermore, the bus electrodes included in the positive and negative electrodes may be linear, wavy, or bent-wire bus electrodes, and the specific shapes of the bus electrodes included in the positive and negative electrodes can be set according to the actual application scenario and are not specifically limited here.

[0052] Here, as shown in Figures 3 to 5, each bus electrode 5 includes a plurality of bus electrode segments 7 distributed at intervals in the second direction. Specifically, the plurality of bus electrode segments 7 included in the same bus electrode 5 may be arranged in the same plane in the first direction. Alternatively, in the same bus electrode 5, at least one pair of bus electrode segments 7 are arranged at intervals in the first direction. In actual application processes, the logarithm of the bus electrode segments 7 arranged at intervals in the first direction in the same bus electrode 5 can be set according to the actual application scene, as long as it is applicable to the back contact battery provided by the embodiment of the present invention.

[0053] Furthermore, the first and second directions described above may be any two different directions, parallel to the non-light-receiving surface. For example, as shown in Figures 3 to 5, if the cross-sectional shape of the battery body 1 is rectangular, the first direction may be parallel to the longer side of the rectangle, and the second direction may be parallel to the shorter side of the rectangle. In this case, the first direction is perpendicular to the second direction.

[0054] The size of the second-direction spacing between two adjacent bus electrode segments on the same bus electrode can be set according to actual needs and is not specifically limited here. For example, the second-direction spacing between two adjacent bus electrode segments on the same bus electrode may be 0.4 mm to 2 mm. For example, the spacing may be 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, or 2 mm. In this case, the size of the second-direction spacing between two adjacent bus electrode segments on the same bus electrode is appropriate, preventing the bus electrode segment from being connected to a current collector electrode of opposite polarity and causing a short-circuit problem due to a small spacing, and ensuring that each bus electrode segment is separated from a current collector electrode of opposite polarity by the spacing. Furthermore, the larger spacing reduces the length of each bus electrode segment in the second direction, preventing interference with the concentration of carriers generated by photon absorption at the corresponding position of the battery body onto the bus electrode segments. This ensures that each bus electrode segment has high carrier concentration capability, thereby further improving the electrical performance of the back contact battery.

[0055] Regarding the above-mentioned connecting electrodes, all connecting electrodes included in both the positive and negative electrodes are continuous connecting electrodes. Continuous connecting electrodes are connecting electrodes without interruption. Furthermore, in the embodiments of this application, the width of the connecting electrodes included in both the positive and negative electrodes is not limited. For example, the width of the connecting electrodes may be the same as the width of the bus electrodes or the same as the width of the current collector electrodes. The number of connecting electrodes included in both the positive and negative electrodes may be one or more. Here, the number of connecting electrodes included in the positive electrode may be the same as or different from the number of connecting electrodes included in the negative electrode. The specific formation position of each connecting electrode on the non-light-receiving surface of the battery body can be set according to actual needs, as long as it is ensured that each connecting electrode is located outside in the first direction of all the bus electrodes included in the positive and negative electrodes. Here, as shown in Figure 3, the connecting electrode 6 included in the positive electrode 2 and the connecting electrode 6 included in the negative electrode 3 may be located on the same outside in the first direction of all the bus electrodes 5. In this case, the connecting electrode 6 can be separated from the current collector electrode 4, which has the opposite polarity to itself, via an insulating material. Naturally, mutual insulation between the two may be achieved by other means. Alternatively, as shown in Figures 4 and 5, at least one connecting electrode 6 included in the positive electrode 2 is located on the first outer side in the first direction of all the bus electrodes 5 included in the positive electrode 2 and the negative electrode 3. At least one connecting electrode 6 included in the negative electrode 3 is located on the second outer side in the first direction of all the bus electrodes 5 included in the positive electrode 2 and the negative electrode 3. The second outer side and the first outer side are provided opposite each other. In this case, it is possible to prevent short-circuit problems from occurring when connecting electrodes 6 with opposite polarities are located on the same outer side, and to ensure that the back contact battery has stable electrical performance.

[0056] When the above technical solution is adopted, as shown in Figures 3 to 5, in the back contact battery provided by the embodiment of the present application, each bus electrode 5 includes a plurality of bus electrode segments 7 distributed at intervals in the second direction, and two adjacent bus electrode segments 7 on the same bus electrode 5 are spaced apart from the current collector electrodes 4 with opposite polarity to themselves. In this case, since no short-circuit problem occurs even if insulating material is not placed between each bus electrode 5 and the current collector electrode 4 with opposite polarity to itself, the amount of insulating material used can be reduced, and the manufacturing cost of the back contact battery can be reduced.

[0057] Furthermore, as shown in Figures 3 to 5, different bus electrode segments 7 included in each bus electrode 5 are connected to corresponding current collector electrodes 4 of the same polarity, thereby concentrating the carriers collected at the corresponding positions on the current collector electrodes 4. Also, if at least one current collector electrode 4 included in the positive electrode 2 is a continuous current collector electrode, the continuous current collector electrode included in the positive electrode 2 can equalize the currents of different bus electrode segments 7 connected via the continuous current collector electrode by connecting bus electrode segments 7 belonging to different bus electrodes 5 in the positive electrode 2. Next, the connecting electrode 6 included in the positive electrode 2 is connected to all current collector electrodes 4 included in the positive electrode 2, and by connecting the current collector electrodes 4 included in the positive electrode 2, it further connects different bus electrode segments 7 connected to the current collector electrodes 4 included in the positive electrode 2. This configuration further suppresses current mismatch between different bus electrodes 5 included in the positive electrode 2, and connects all bus electrode segments 7 belonging to the same bus electrode 5 via the connecting electrode 6, which is advantageous in preventing some bus electrode segments 7 included in a bus electrode 5 from becoming unable to connect to the string interconnect member due to bias of the string interconnect member welded to one of the bus electrodes 5 included in the positive electrode 2. It is also advantageous in ensuring that carriers collected by each bus electrode segment 7 included in the bus electrode 5 can all be drawn out via the string interconnect member, and further advantageous in improving the photoelectric conversion efficiency of the back contact battery. Similarly, the negative electrode 3 in the embodiment of this application also has the beneficial effects of the positive electrode 2 described above, and a detailed explanation is omitted here.

[0058] In some implementations, each continuous current collector electrode is connected to a bus electrode 5 having the same polarity as the continuous current collector electrode. For example, each continuous current collector electrode of positive electrode 2 is connected to the bus electrode 5 of positive electrode 2, and each continuous current collector electrode of negative electrode 3 is connected to the bus electrode 5 of negative electrode 3. In this way, the mismatch in current between different bus electrodes 5 is reduced. There isn't .

[0059] In actual application processes, as shown in Figures 3 and 4, each of the connecting electrodes 6 may be located on the current collecting electrodes 4 included in the positive electrode 2 and the negative electrode 3. Alternatively, as shown in Figure 5, each of the connecting electrodes 6 may be located at the ends in the first direction of all the current collecting electrodes 4 included in the positive electrode 2 and the negative electrode 3. In this case, each connecting electrode 6 may be located at the edge position in the first direction of the battery body 1, which is advantageous in increasing the distance between each connecting electrode 6 and the bus electrode 5 which has the opposite polarity to itself, thereby preventing short circuits.

[0060] Furthermore, as shown in Figures 3 and 4, all current-collecting electrodes 4 included in the positive electrode 2 and negative electrode 3 described above may be arranged so that both ends in the first direction are on the same plane. In this case, all current-collecting electrodes 4 included in the positive electrode 2 and negative electrode 3 can be regularly distributed on the non-photoreceiving surface of the electrode body in the first direction, which is advantageous for effectively collecting carriers generated by photon absorption in each part of the battery body 1 in the first direction by each current-collecting electrode 4, and is also advantageous for improving the electrical performance of the back-contact battery.

[0061] Alternatively, the end of at least one current collector electrode in the first direction may be alternately arranged with the ends of the remaining current collector electrodes in the first direction. In this case, as shown in Figure 5, all current collector electrodes 4 included in the positive electrode 2 have both ends in the same plane in the first direction, all current collector electrodes 4 included in the negative electrode 3 have both ends in the same plane in the first direction, and the ends of all current collector electrodes 4 included in the positive electrode 2 in the first direction may be alternately arranged with the ends of all current collector electrodes 4 included in the negative electrode 3 in the first direction. In this case, each connecting electrode 6 is connected only to current collector electrodes 4 of the same polarity as itself without the placement of insulating material, and is advantageous for separating itself from current collector electrodes 4 of the opposite polarity.

[0062] In one possible implementation, each current collector electrode has a gap extending in a first direction with respect to a connecting electrode of opposite polarity to itself. Here, as shown in Figure 5, this gap may be the distance between the end of each current collector electrode 4 in the first direction and the connecting electrode 6 of opposite polarity to itself. Alternatively, it may be a gap provided on the current collector electrode, which is used to divide the current collector electrode into at least two current collector electrode segments.

[0063] Specifically, the size of the interval can be set according to the actual needs and is not limited to that here.

[0064] When the above technical solution is adopted, as shown in Figure 5, each current collector electrode 4 can be separated from the connecting electrode 6 of the opposite polarity by the spacing extending in the first direction. As a result, short-circuit problems do not occur even if insulating material is not placed between each current collector electrode 4 and the connecting electrode 6 of the opposite polarity, thus further reducing the amount of insulating material used and lowering the manufacturing cost of back contact batteries.

[0065] In actual application processes, as mentioned above, each bus electrode includes multiple bus electrode segments distributed at intervals in the second direction. Specifically, in terms of numbers, the number of bus electrode segments included in bus electrodes of the same polarity but different polarities may be the same or different. For example, as shown in Figures 3 to 5, each bus electrode 5 included in the positive electrode 2 includes 10 bus electrode segments 7. Here, as shown in Figures 3 to 5, if the number of bus electrode segments 7 included in bus electrodes 5 of the same polarity but different polarities is the same, it is advantageous for the multiple bus electrodes 5 included in the positive electrode 2 and the negative electrode 3 to be uniformly distributed on the non-photosensitive surface of the battery body 1. Furthermore, the distance between each part of the battery body 1 parallel to the non-photosensitive surface and the corresponding bus electrode 5 can be made approximately equal. This is advantageous for carriers generated by photon absorption in each part of the battery body 1 to be collected by the corresponding current collector electrode 4 in a timely manner and concentrated on the corresponding bus electrode 5 in a timely manner. Thus, the carrier recombination rate is reduced, and the photoelectric conversion efficiency of the back-contact battery is further improved.

[0066] Regarding length, the lengths of different bus electrode segments contained within the same bus electrode may be the same or different. Here, the length direction of the bus electrode segments is parallel to the second direction. For example, as shown in Figure 3, the bus electrode located in the first row is bus electrode 5 contained within positive electrode 2, and the different bus electrode segments 7 contained within bus electrode 5 are arranged in order from top to bottom. Here, the first to tenth bus electrode segments contained within bus electrode 5 have the same length in the second direction.

[0067] Furthermore, the lengths of any two bus electrode segments belonging to different bus electrodes in the second direction may be the same or different. Here, if the lengths of any two bus electrode segments belonging to different bus electrodes are the same, it is advantageous for all bus electrodes in the back contact battery to be uniformly distributed on the non-light-receiving surface of the battery body, and it is advantageous for the carriers generated by light absorption by the battery body to be extracted by the bus electrodes in a timely manner, thus reducing the carrier recombination rate and further improving the electrical performance of the back contact battery.

[0068] Regarding the distribution, the spacing between any two pairs of bus electrode segments on the same bus electrode may be the same or different. Here, as shown in Figures 3 to 5, when the spacing between any two pairs of bus electrode segments 7 on the same bus electrode 5 is equal, the multiple bus electrode segments 7 contained in the same bus electrode 5 are distributed at equal intervals in the second direction. For the beneficial effects in this case, refer to the analysis of the beneficial effects when the number of bus electrode segments 7 contained in the same bus electrode 5 with different polarities is the same, as described above, and a detailed explanation is omitted here.

[0069] Furthermore, bus electrode segments of the same order in bus electrodes of the same polarity but different polarities may be arranged alternately, and both ends may be on the same plane in the same direction. Bus electrode segments of different orders in the same bus electrode are distributed at intervals in a second direction. Here, as shown in Figures 3 to 5, when bus electrode segments 7 of the same order in bus electrodes 5 of the same polarity but different polarities have both ends on the same plane in the same direction, the spacing in the segments of the same order in bus electrodes 5 of the same polarity but different polarities can extend in that direction, which is advantageous for the current collector electrode 4 to become a linear current collector electrode extending in a single straight line, and is advantageous for simplifying the structure of the current collector electrode 4 included in the positive electrode 2 and negative electrode 3.

[0070] As shown in Figure 6(1), the heights in the second direction of bus electrode segments 7 of the same order in bus electrodes 5 with opposite polarities may partially overlap. Bus electrode segments 7 of different orders in the same bus electrode 5 are distributed at intervals in the second direction. In this case, if other elements are the same, the partial overlap of the heights in the second direction of bus electrode segments 7 of the same order in bus electrodes 5 with opposite polarities allows for an increase in the length of each bus electrode segment 7, which is advantageous in improving the carrier concentration ability of each bus electrode segment 7. Alternatively, as shown in Figure 6(2), the ends of the bus electrode segments 7 of the same order in bus electrodes 5 with opposite polarities described above may be alternately arranged in the second direction. Bus electrode segments 7 of different orders in the same bus electrode 5 are distributed at intervals in the second direction. In this case, the heights in the second direction of bus electrode segments 7 of the same order in bus electrodes 5 with opposite polarities are different. Based on this, if other elements are the same, the bus electrode segments 7 in the same order on the bus electrode 5 with opposite polarities are arranged alternately at both ends in the second direction, thereby increasing the spacing between two adjacent bus electrode segments 7 included in the same bus electrode 5. This further prevents short circuits caused by the connection between each bus electrode segment 7 and the current collector electrode 4 which has the opposite polarity, and improves the electrical stability of the back contact battery.

[0071] In one possible implementation, as shown in Figures 7 and 8, the back contact battery further includes welds 8, and each weld 8 is connected to a corresponding bus electrode 5, thereby facilitating the connection between the bus electrode 5 and the corresponding string interconnecting member.

[0072] Specifically, in terms of numbers, each bus electrode may be connected to only one weld. Alternatively, as shown in Figures 7 and 8, each bus electrode 5 may be connected to multiple welds 8 distributed at intervals in the second direction. Here, when each bus electrode 5 is connected to multiple welds 8 distributed at intervals in the second direction, compared to when each bus electrode 5 is connected to only one weld 8, problems such as solder fracture of the interconnecting member within the string due to deterioration of welding strength because the interconnecting member within the string is welded to only one weld 8 can be prevented, and the welding quality during series welding of the back contact battery provided by the embodiment of the present application can be improved.

[0073] Furthermore, when each bus electrode is connected to multiple welds distributed at intervals in the second direction, the number of welds connected to different bus electrodes may be the same or different. Here, as shown in Figures 7 and 8, when the number of welds 8 connected to different bus electrodes 5 is the same, it is advantageous for uniformly distributing the multiple welds 8 included in the back contact battery above the battery body 1, and it is advantageous for a conventional series welding apparatus to connect multiple back contact batteries provided in the embodiment of the present invention in series via an in-string interconnecting member, thereby improving welding efficiency.

[0074] Regarding the distribution, as shown in Figures 7 and 8, multiple welds 8 connected to the same bus electrode 5 may be distributed at equal intervals. This is advantageous for improving the welding quality between the string interconnecting member and the corresponding bus electrode 5.

[0075] Regarding shape, the cross-sectional shape of the weld connected to the bus electrode may be rectangular, circular, elliptical, or the like. The length of the weld in the first direction may be greater than or equal to the width of the bus electrode in the first direction, which is advantageous in improving the welding strength between the bus electrode and the corresponding string interconnecting member. For example, if the cross-sectional shape of the weld is rectangular, the longer side of the rectangle may be 3 mm and the shorter side may be 2 mm.

[0076] In one example, as shown in Figures 7 and 8, of all the welds 8 included in the back contact battery, at least a portion of the weld 8 located between two adjacent bus electrode segments 7 included in the same bus electrode 5 is a Class 1 weld 9, and the remaining welds 8 are Class 2 welds 10. Of all the current collector electrodes 4 included in the positive electrode 2 and negative electrode 3, at least a portion of the current collector electrode 4 that is at the same height as the Class 1 weld 9 in a second direction is a Class 1 current collector electrode 11, and the remaining current collector electrodes 4 are Class 2 current collector electrodes 12. Each bus electrode 5 has the same polarity as the weld 8 provided on it. Each Class 1 current collector electrode 11 includes a plurality of current collector electrode segments 13 distributed at intervals in a first direction, and two adjacent current collector electrode segments 13 included in the same Class 1 current collector electrode 11 are spaced apart from the Class 1 weld 9 which has the opposite polarity to itself.

[0077] Specifically, the number of Class 1 and Class 2 welds included in the back contact battery can be set according to actual needs and is not specifically limited here. For example, as shown in Figure 7, each weld 8 included in the back contact battery is a Class 1 weld 9. Alternatively, some of the welds included in the back contact battery are Class 1 welds, and the remaining welds are Class 2 welds. For example, as shown in Figure 8, if the number of columns in which the welds 8 are located from right to left is sorted, the welds 8 in the first column of the back contact battery are Class 1 welds 9, and the welds 8 in the remaining columns are Class 2 welds 10. Furthermore, or, each weld included in the back contact battery is a Class 2 weld.

[0078] Furthermore, the number and length of current collector electrode segments distributed at intervals in the first direction within each Class 1 current collector electrode, and the spacing between two adjacent current collector electrode segments within the same Class 1 current collector electrode, can be set according to the number of Class 1 welds that are at the same height as at least a portion of the Class 1 current collector electrode in the second direction and have opposite polarity to itself, and according to actual needs, and are not specifically limited here.

[0079] When the above technical solution is adopted, short-circuit problems do not occur even if insulating material is not placed between each Class 1 current collector electrode and the welded part with opposite polarity to itself. Therefore, the amount of insulating material used can be reduced, and the manufacturing cost of back contact batteries can be reduced.

[0080] In a second embodiment, the embodiment of the present application further provides a solar cell structure. As shown in Figure 9, the solar cell structure includes an insulating material 14 and a back contact cell provided in the first embodiment and various realizations thereof. The insulating material 14 covers the space between at least two adjacent bus electrode segments included in each bus electrode.

[0081] Specifically, the width of the insulating material can be set according to the actual needs and is not specifically limited here. For example, the width of the insulating material may be greater than the width of the bus electrode in the first direction and less than a predetermined width. The predetermined width may be 1.5 mm to 10 mm. In this case, the width of the insulating material in the first direction is appropriate, and it is possible to prevent an increase in the amount of insulating material used due to a large width of the insulating material, which is advantageous in reducing the manufacturing cost of back contact batteries. Furthermore, a small width of the insulating material can prevent the need to strictly require the placement of interconnecting members within the string when connecting different back contact batteries, which is advantageous in reducing the difficulty of welding when connecting at least two back contact batteries.

[0082] In one possible implementation, as shown in Figure 9, if the back contact battery includes a weld 8 and each weld 8 is connected to a corresponding bus electrode, the solar cell structure further includes a conductive adhesive 15. The conductive adhesive 15 is provided at least one weld 8. In this case, within a predetermined range, if the thickness of the insulating material 14 is large, the insulating effect of the insulating material 14 is high. When the thickness of the insulating material 14 is relatively large, the uppermost height of the insulating material 14 may be greater than the uppermost height of the weld 8. Based on this, by providing the conductive adhesive 15 at each weld 8, the uppermost height of the structure consisting of the conductive adhesive 15 and the weld 8 becomes greater than or equal to the uppermost height of the insulating material 14, ensuring that the string interconnecting members can be connected to the corresponding weld 8. As can be seen from the above, the thickness of the conductive adhesive 15 can be determined according to the height difference between the weld 8 and the uppermost part of the insulating material 14, and is not specifically limited here.

[0083] In a third aspect, embodiments of the present application further provide a solar cell module, which includes a back-contact battery provided by the first aspect and various implementations thereof, or a solar cell structure provided by the second aspect and various implementations thereof.

[0084] The beneficial effects of the second and third embodiments and their various realizations in the embodiments of this application may be explained by referring to the analysis of the beneficial effects of the first embodiment and its various realizations, and a detailed explanation is omitted here.

[0085] The above are merely specific embodiments of the present application, and the scope of protection of this application is not limited thereto. Any changes or replacements that a person skilled in the art can easily conceive of within the scope of the art described in this application are all included within the scope of protection of this application. Therefore, the scope of protection of this application shall be the same as the scope of protection of the claims.

[0086] The terms "one embodiment," "example," or "one or more examples" used herein mean that the specific features, structure, or properties described by the examples are included in at least one embodiment of the present invention. It should also be noted that the phrase "in one embodiment" in this specification does not necessarily refer to the same example.

[0087] The specification provided herein provides a great deal of specific detail. However, it can be understood that embodiments of the present invention may be carried out without these specific details. In some examples, well-known methods, structures, and techniques are not described in detail so as not to obscure the understanding of this specification.

[0088] In a claim, no reference numeral between parentheses shall be considered limiting to the claim. The term “including” shall not preclude the existence of elements or steps not described in the claim. The term “one” or “one” preceding an element shall not preclude the existence of multiple such elements. The terms “first,” “second,” and “third,” etc., do not represent any order. These terms may be interpreted as names.

[0089] Finally, it should be explained that the above embodiments are merely for illustrating the technical solutions of the present invention and do not limit them. Although the present invention has been described in detail with reference to the above embodiments, it will be understood by those skilled in the art that modifications to the technical solutions described in each of the above embodiments, or equivalent substitutions of some of their technical features, are possible. These modifications or substitutions do not cause the essence of the relevant technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present invention. [Explanation of symbols]

[0090] 1. Battery unit 2 Positive electrode 3 negative electrode 4 Current collector electrode 5. Bus electrodes 6. Connecting electrodes 7 Bus electrode segment 8. Welded section 9. Class 1 welds 10. Welds of Class 2 11 Class 1 Current Collector Electrodes 12. Class 2 current collector electrodes 13 Current collector electrode segment 14. Insulating materials 15 Conductive adhesive

Claims

1. A back contact battery comprising a battery body and a positive electrode and a negative electrode formed on the non-light-receiving surface of the battery body, wherein both the positive electrode and the negative electrode each include a plurality of current-collecting electrodes, a plurality of bus electrodes, and at least one connecting electrode. The current collector electrodes included in the positive electrode and the current collector electrodes included in the negative electrode both extend in a first direction and are arranged alternately at intervals in a second direction different from the first direction, and at least one of the current collector electrodes included in the positive electrode and at least one of the current collector electrodes included in the negative electrode are both continuous current collector electrodes. The bus electrodes included in the positive electrode and the bus electrodes included in the negative electrode both extend in the second direction and are arranged alternately at intervals in the first direction, each bus electrode is connected to the current collector electrode having the same polarity as itself, each bus electrode includes a plurality of bus electrode segments distributed at intervals in the second direction, and two adjacent bus electrode segments on the same bus electrode are spaced apart from the current collector electrodes with opposite polarity to itself by the spacing between them. Each of the connecting electrodes is located outside in the first direction of all the bus electrodes included in the positive electrode and the negative electrode, and each of the connecting electrodes is connected to all of the current collector electrodes of the same polarity as itself, and is insulated from each other by the current collector electrodes of the opposite polarity to itself. The back contact battery further includes a welded portion, each of which is connected to the corresponding bus electrode. Of all the welds included in the back contact battery, at least a portion of the weld located between two adjacent bus electrode segments included in the same bus electrode is a Class 1 weld, and the remaining welds are Class 2 welds. Of all the current-collecting electrodes included in the positive electrode and the negative electrode, at least a portion of which is at the same height as the Class 1 weld in the second direction is a Class 1 current-collecting electrode, and the remaining current-collecting electrodes are Class 2 current-collecting electrodes. A back-contact battery in which each bus electrode has the same polarity as the welded portion provided thereon, each Class 1 current collector electrode includes a plurality of current collector electrode segments distributed at intervals in the first direction, and two adjacent current collector electrode segments included in the same Class 1 current collector electrode are spaced apart from the Class 1 welded portion which has the opposite polarity to the electrode itself.

2. The back contact battery according to claim 1, wherein each continuous current collector electrode is connected to one or more bus electrode segments having the same polarity as the continuous current collector electrode itself.

3. The back contact battery according to claim 1, wherein the distance between two adjacent bus electrode segments in the same bus electrode in the second direction is 0.4 mm to 2 mm.

4. Each of the connecting electrodes is located at the end in the first direction of all the current collecting electrodes included in the positive electrode and the negative electrode, and / or The back contact battery according to claim 1, wherein all current-collecting electrodes included in the positive electrode and the negative electrode have both ends in the same plane in the first direction.

5. The at least one connecting electrode included in the positive electrode is located first outward in the first direction of all the bus electrodes included in the positive electrode and the negative electrode, The back contact battery according to claim 1, wherein the at least one connecting electrode included in the negative electrode is located second outside in the first direction of all the bus electrodes included in the positive electrode and the negative electrode, and the second outside and the first outside are provided opposite each other.

6. The back contact battery according to any one of claims 1 to 5, wherein each current collecting electrode has a spacing extending in the first direction with respect to the connecting electrode having opposite polarity to itself.

7. Multiple bus electrode segments included in the same bus electrode are distributed at equal intervals in the second direction, and / or The back contact battery according to any one of claims 1 to 5, wherein the lengths of the different bus electrode segments included in the same bus electrode are the same, and the length direction of the bus electrode segments is parallel to the second direction.

8. The number of bus electrode segments included in the bus electrodes of the same polarity but different polarities is the same. and / or, Bus electrode segments of the same order in the same bus electrode with different polarities have both ends on the same plane in the same direction, and bus electrode segments of the same bus electrode with different orders are distributed at intervals in the second direction, and / or The back contact battery according to any one of claims 1 to 5, wherein the bus electrode segments of the same order in the bus electrode with opposite polarities are arranged alternately at both ends in the second direction, and the bus electrode segments of different orders in the same bus electrode are distributed at intervals in the second direction.

9. The battery comprises an insulating material and a back contact battery according to any one of claims 1 to 5, The insulating material covers the space between at least two adjacent bus electrode segments included in each bus electrode in the solar cell structure.

10. The width of the insulating material is greater than the width of the bus electrode and less than a predetermined width in the first direction. The solar cell structure according to claim 9, wherein the predetermined width is 1.5 mm to 10 mm.

11. The solar cell structure according to claim 9, wherein the back contact battery is the back contact battery according to claim 9, and the solar cell structure further includes a conductive adhesive provided on one of the welded portions.

12. A solar cell module comprising a back-contact battery according to any one of claims 1 to 5.

13. A solar cell module comprising the solar cell structure described in claim 9.

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