CN219419041U - Solar cell and battery - Google Patents

Abstract

The utility model provides a solar cell and a battery, wherein the solar cell can comprise: a substrate; an electrode on a surface of the substrate, the electrode comprising: a plurality of fine grids arranged in parallel with each other, and a welding strip above the fine grids arranged in parallel and intersecting the fine grids; the welding strip and the fine grid are connected through the conductive adhesive at the junction. In the embodiment of the disclosure, before welding, the conductive adhesive is fully contacted with the welding strip and the fine grid, so that the welding strip and the fine grid cannot easily drift each other in the subsequent welding process, the phenomenon of insufficient empty cold joint or pull-off force between the welding strip and the fine grid welding strip is avoided, and the performance of the solar cell is improved.

Description

Solar cell and battery

Technical Field

The utility model relates to the technical field of photovoltaics, in particular to a solar cell and a battery.

Background

The solar cell is a photoelectric semiconductor sheet which directly generates electricity by utilizing sunlight, is also called a solar chip or a photocell, and can output voltage instantly and generate current under the condition of a loop as long as the solar cell is subjected to illuminance meeting a certain illuminance condition.

The cell sheet is a basic constituent unit of a solar cell, and is obtained by forming electrodes on the surface of a substrate, the electrodes being used to collect photo-generated current. The electrode of the solar cell generally comprises a main grid and an auxiliary grid, the photo-generated current is transmitted to the main grid through the auxiliary grid and is conducted out through the welding strip by the main grid, and the main grid also plays a role of fixing the welding strip and realizing mechanical connection with the welding strip. However, the main grid needs to use a large amount of silver paste, and the cost is high. Some designs eliminate the main grid, use the welding belt to directly weld with the auxiliary grid line for connection,

the auxiliary grid after the main grid is cancelled is a fine grid line, but the empty virtual welding or low pulling force of the welding strip and the fine grid line can occur after the welding strip and the battery without the main grid are welded, and the problems that the welding strip and the battery piece are directly separated in the assembly process, or the contact abnormal power attenuation exceeds standard and the like occur in the aging test after packaging can occur.

Disclosure of Invention

Aiming at the problems in the prior art, the utility model aims to provide a solar cell and a battery so as to solve the problems of cost and welding reliability of the solar cell in the related art.

The embodiment of the utility model provides a solar cell, which comprises:

a substrate;

an electrode on a surface of the substrate, the electrode comprising: a plurality of fine grids arranged in parallel with each other, and a welding strip above the fine grids arranged in parallel and intersecting the fine grids;

the welding strip and the fine grid are connected through the conductive adhesive at the junction.

In some embodiments, the solder strip and the fine grid have a plurality of intersections, wherein an electrically conductive adhesive is disposed at least one intersection and soldered at least one intersection.

In some embodiments, the amount of conductive adhesive at the plurality of intersections of the solder strips and the fine grid is no less than half of the total number of intersections between the solder strips and the fine grid, and no greater than the total number of intersections between the solder strips and the fine grid.

In some embodiments, the conductive adhesive is dot-like or wire-like in shape.

In some embodiments, the wire-mounted conductive adhesive is parallel to and in contact with the solder strip.

In some embodiments, the conductive adhesive is a solder paste or a conductive paste.

In some embodiments, the solar cell is a PERC solar cell, a TOPCon solar cell, a heterojunction cell, or an IBC cell.

The disclosed embodiments also provide a solar cell, including:

any one of the solar cells described above;

wherein, the welding of a plurality of solar wafer is electrified to be connected.

The solar cell and the battery provided by the utility model have the following advantages:

the solar cell may include: a substrate; an electrode on a surface of the substrate, the electrode comprising: a plurality of fine grids arranged in parallel with each other, and a welding strip above the fine grids arranged in parallel and intersecting the fine grids; the welding strip and the fine grid are connected through the conductive adhesive at the junction. In the embodiment of the disclosure, after solidification and/or welding, the conductive adhesive connects the welding strip and the battery fine grid electrically and mechanically, so that the welding strip cannot easily deviate in the subsequent lamination and lamination process, the phenomenon of insufficient empty virtual welding or pulling-off force between the welding strip and the fine grid welding strip is avoided, and the performance of the solar cell is improved.

Drawings

Other features, objects and advantages of the present utility model will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings.

Fig. 1 is a schematic plan view of a solar cell of the related art;

fig. 2 is a schematic plan view of a solar cell provided in an embodiment of the present disclosure;

fig. 3 is a schematic plan view of a solar cell provided in an embodiment of the disclosure in an intermediate stage of a manufacturing process.

Detailed Description

Other advantages and effects of the present application will be readily apparent to those skilled in the art from the present disclosure, by describing embodiments of the present application with specific examples. The present application may be embodied or applied in other specific forms and details, and various modifications and alterations may be made to the details of the present application from different points of view and application without departing from the spirit of the present application. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other.

The embodiments of the present application will be described in detail below with reference to the drawings so that those skilled in the art to which the present application pertains can easily implement the same. This application may be embodied in many different forms and is not limited to the embodiments described herein.

In the description of the present application, reference to the terms "one embodiment," "some embodiments," "examples," "particular examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the various embodiments or examples, and features of the various embodiments or examples, presented herein may be combined and combined by those skilled in the art without conflict.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the context of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

For the purpose of clarity of the description of the present application, components that are not related to the description are omitted, and the same or similar components are given the same reference numerals throughout the description.

Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" with other elements interposed therebetween. In addition, when a certain component is said to be "included" in a certain device, unless otherwise stated, other components are not excluded, but it means that other components may be included.

When a device is said to be "on" another device, this may be directly on the other device, but may also be accompanied by other devices therebetween. When a device is said to be "directly on" another device in contrast, there is no other device in between.

Although the terms first, second, etc. may be used herein to connote various elements in some instances, the elements should not be limited by the terms. These terms are only used to distinguish one element from another element. For example, a first interface, a second interface, etc. Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, steps, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; A. b and C). An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the language clearly indicates the contrary. The meaning of "comprising" in the specification is to specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but does not preclude the presence or addition of other features, regions, integers, steps, operations, elements, and/or components.

Although not differently defined, including technical and scientific terms used herein, all terms have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The term addition defined in the commonly used dictionary is interpreted as having a meaning conforming to the contents of the related art document and the current hint, so long as no definition is made, it is not interpreted as an ideal or very formulaic meaning too much.

The related art proposes a solar cell without a main grid, as shown in fig. 1, which retains a sub-grid 1 in the case of deleting the main grid, and then photo-generated current is directly conducted from the sub-grid 1 to a solder strip 2 and conducted out, which shortens a current transmission path to some extent, and reduces power loss.

The auxiliary grid is also called a fine grid because of adopting a fine grid structure. The thin grid is thinner, so that the problems of empty virtual welding and insufficient pulling-out force can occur when the thin grid is welded with the welding strip, and the welding strip is directly separated from the battery piece, or the contact abnormality, the power attenuation exceeding standard and the like occur in the aging test after packaging. This is a problem of poor performance of solar cells.

In the case of specifying the above problems, the inventors specify that the welding performance between the fine grid and the solder strip is one of the reasons that the performance of the solar cell is poor, and thus propose the solar cell of the embodiments of the present disclosure.

As shown in fig. 2, a solar cell according to an embodiment of the present disclosure may include:

a substrate 20;

an electrode 21 located on the surface of the substrate 20, the electrode 21 comprising: a plurality of fine bars 211 arranged in parallel with each other, and a solder strip 212 above the plurality of fine bars 211 arranged in parallel and intersecting the fine bars 211;

the bonding tape 212 and the fine grid 211 are provided with conductive adhesive 22 at the junction (shown in connection with fig. 3), and the bonding tape 212 and the fine grid 211 are connected by the conductive adhesive 22.

In the embodiment of the disclosure, before welding, the conductive adhesive 22 is fully contacted with the solder strip 212 and the fine grid 211, so that the solder strip 212 and the fine grid 211 cannot easily drift each other in the subsequent welding process, the phenomenon of insufficient empty dummy solder or pull-off force between the solder strip 212 and the fine grid 211 is avoided, and the performance of the solar cell is improved.

In the disclosed embodiment, conductive adhesive 22 (shown in fig. 3) is applied to a designated location on fine grid 211 during the manufacturing process, then bonding ribbon 212 (shown in fig. 2) is placed, and then bonding is performed to join fine grid 211 and bonding ribbon 212 together.

In the disclosed embodiment, the substrate 20 is formed using a semiconductor wafer.

The surface of the substrate 20 may be referred to as the front side. That is, the main grid is omitted from the front electrode, only the thin grid 211 (also called a secondary grid) is used, and the welding strip 212 replaces the main grid in the front electrode of the traditional solar cell, so that the current collected by the thin grid 211 is collected and transmitted.

In particular, in the presently disclosed embodiments, the front electrode is formed of a plurality of thin grids 211 that are parallel to each other and equally spaced on the front surface of the semiconductor wafer. The bonding pads 212 are perpendicular to the fine grid 211, and the bonding pads 212 are spaced apart from each other. Each solder strip 212 is crossed with each fine grid 211 and conducted at the crossing point to realize electric connection, thereby forming a grid structure.

In the disclosed embodiment, the solder strip 212 and the fine grid 211 have a plurality of intersections, such as the black spot shown in fig. 2, wherein a conductive adhesive 22 is disposed at least one intersection and soldered at least one intersection.

In this case, the connection stability between the fine grid 211 and the solder ribbon 212 is higher by the bonding action and soldering of the conductive adhesive 22, and the cell performance of the solar cell is reliable and stable.

In the disclosed embodiment, at the plurality of intersections of the bonding tape 212 and the fine grid 211, the amount of the conductive adhesive 22 is not less than half of the total number of intersections between the bonding tape 212 and the fine grid 211, and is not greater than the total number of intersections between the bonding tape 212 and the fine grid 211.

By the design, the bonding between the welding strip 212 and the fine grid 211 is firmer.

In the presently disclosed embodiment, the conductive adhesive 22 is dot-shaped. For the dot-shaped conductive adhesive 22, the number of the arrangement thereof can be referred to as above.

In the embodiment of the present disclosure, the conductive adhesive 22 is in a linear shape, and the linear design makes the connection between the fine grid 211 and the bonding tape 212 more stable.

In the presently disclosed embodiments, for the linear conductive bonds, they are parallel to and in contact with the fine grid.

In the disclosed embodiment, the conductive adhesive 22 is solder paste or conductive paste, or the like. The conductive adhesive is an adhesive with certain conductivity after being solidified or dried. The conductive paste is also called conductive silver paste, and can be classified into polymer conductive paste and sintered type silver conductive paste, wherein the former is characterized in that the polymer is used as a bonding phase, and the latter is used as a bonding phase.

In the embodiments of the present disclosure, the solar cell is a PERC (Passivated emitter rear contact solar cells) solar cell, a TOPCon solar cell, a heterojunction cell, or an IBC cell.

The PERC back passivation film is added on the back of the PERC solar cell, and the contact is optimized from full contact to back local point contact, so that the back recombination loss of the solar cell is greatly reduced, the open-circuit voltage of the solar cell is improved, the efficiency of the solar cell is obviously improved, and the current common efficiency of the PERC solar cell produced in mass can reach more than 21%.

The TOPCon solar cell is also called a tunneling oxide passivation contact solar cell, and adopts an n-type silicon wafer, the back surface structure of the TOPCon solar cell generally adopts a layer of silicon oxide covered on the back surface as a tunneling layer, then an n-type doped polysilicon layer (i.e. an n+ Poly-Si layer) is covered on the back surface, and an Ag metal electrode layer is arranged on the outermost layer of the back surface. The silicon oxide tunneling layer prevents the semiconductor from directly contacting the metal electrode, reduces the recombination on the surface of the battery, and reduces the loss of electron collection.

The heterojunction solar cell is a device for converting solar energy into electric energy by utilizing photovoltaic effect, and the core of the heterojunction solar cell is a semiconductor PN junction. The heterojunction technology is HJT, which is called Heterojunction Technology.

The embodiment of the disclosure also provides a solar cell, wherein the solar cell comprises a plurality of solar cells, and the solar cells are assembled by the solar cells. Wherein, the welding of a plurality of solar wafer is electrified to be connected.

The foregoing is a further detailed description of the utility model in connection with the preferred embodiments, and it is not intended that the utility model be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the utility model, and these should be considered to be within the scope of the utility model.

Claims (8)

1. A solar cell, comprising:

a substrate;

an electrode on a surface of a substrate, the electrode comprising: a plurality of fine grids arranged in parallel with each other, and a welding strip above the fine grids arranged in parallel and intersecting the fine grids;

the welding strip and the fine grid are connected through the conductive adhesive, and the welding strip is also connected with the fine grid in a welding way.

2. The solar cell of claim 1, wherein the solder strip and the fine grid have a plurality of intersections, wherein the conductive adhesive is disposed at least one intersection and soldered at least one intersection.

3. The solar cell of claim 2, wherein the amount of conductive adhesive at the plurality of intersections of the solder strips and the fine grid is not less than half of the total number of intersections between the solder strips and the fine grid and not greater than the total number of intersections between the solder strips and the fine grid.

4. The solar cell according to claim 1, wherein the conductive adhesive is dot-like or linear in shape.

5. The solar cell of claim 4, wherein the linear conductive adhesive is parallel to and in contact with the fine grid.

6. The solar cell according to claim 1, wherein the conductive adhesive is a solder paste or a conductive paste.

7. The solar cell according to claim 1, wherein the solar cell is a PERC solar cell, a TOPCon solar cell, a heterojunction cell or an IBC cell.

8. A solar cell, comprising:

a plurality of solar cells of any one of claims 1-7;

wherein the solder strips of the plurality of solar cells are electrically connected.