CN220021144U - Welding strip piece, composite film and battery assembly - Google Patents

Abstract

The utility model relates to the technical field of photovoltaics, in particular to a welding strip piece, a composite film and a battery assembly, wherein the welding strip piece is suitable for connecting adjacent battery pieces in series and comprises the following components: the welding strip substrate comprises a welding area and a connecting area, the surface of the welding strip substrate positioned in the welding area comprises a welding plane and a back curved surface which is outwards protruded relative to the welding plane, the welding plane is suitable for facing towards the battery piece and contacting with the battery piece, and the back curved surface is suitable for facing away from the battery piece; the edge area of the welding strip substrate on the welding plane is recessed towards the welding strip substrate to form a first groove, and the wall surface of the first groove is connected with the back curved surface; and the welding film coats the outer surface of the welding strip matrix of the welding zone. The welding strip piece can be accurately welded with the battery piece, and the binding force is strong.

Description

Welding strip piece, composite film and battery assembly

Technical Field

The utility model belongs to the technical field of photovoltaics, and particularly relates to a welding strip piece, a composite film and a battery assembly.

Background

With the frequency of non-renewable energy urgent, solar energy as a new energy provides new possibilities for global energy structures. Inexhaustible solar energy, and solves the problem of energy deficiency.

Solar cells are important devices for realizing conversion from light energy to electric energy, and the current solar cells comprise various types, and are usually connected in series and in parallel to form a cell assembly after the preparation of a cell slice is completed, so that the large-scale application is realized. From the battery piece to the battery assembly, a plurality of battery pieces are connected in series to form a battery string through an interconnection technology, and then a plurality of battery strings are connected in parallel to form the battery assembly through processes such as laying, lamination and the like.

One of the series connection modes is to connect adjacent battery pieces through a welding strip piece, however, in the prior art, when the welding strip piece and the battery pieces are welded, the phenomenon of offset welding and virtual welding caused by offset exists between the welding strip piece and the battery pieces, particularly, along with the development of a photovoltaic market, the market competition is more and more vigorous, the index of reducing the effect is surrounded, in recent years, each photovoltaic enterprise is laying out a solar battery without a main grid to reduce the silver paste consumption of a battery end, and the diameter of the welding strip piece of the solar battery without the main grid is smaller than that of a conventional welding strip piece, so that the welding strip piece of the solar battery without the main grid is easier to offset a thin grid in the welding process, thereby causing welding offset.

Therefore, overcoming the existing cold joint and bias joint between the welding strip piece and the battery piece in the prior art is a technical problem to be solved by the person skilled in the art.

Disclosure of Invention

The utility model aims to overcome the defects of cold joint and offset joint between a welding strip piece and a battery piece in the prior art, thereby providing the welding strip piece, the composite film and the battery component.

The utility model provides a solder strip member, which is suitable for connecting adjacent battery pieces in series, and comprises the following components: the welding strip substrate comprises a welding area and a connecting area, the surface of the welding strip substrate positioned in the welding area comprises a welding plane and a back curved surface which is outwards protruded relative to the welding plane, the welding plane is suitable for facing towards the battery piece and contacting with the battery piece, and the back curved surface is suitable for facing away from the battery piece; the welding strip substrate is recessed towards the welding strip substrate in the edge area of the welding plane to form a first groove, and the wall surface of the first groove is connected with the back curved surface; and the welding film coats the outer surface of the welding strip matrix of the welding zone.

Optionally, the solder strip substrate is strip-shaped, the length direction of the first groove is perpendicular or not perpendicular to the extending direction of the solder strip substrate, and the length direction of the first groove is the extending direction of the first groove.

Optionally, the cross-sectional pattern of the first groove perpendicular to the length direction of the first groove includes a triangle, and the base of the triangle is located on the same plane as the welding plane.

Optionally, an acute included angle is formed between the length direction of the first groove and the extending direction of the welding strip substrate, and the range of the acute included angle is 30-40 degrees.

Optionally, the height of the first groove is 1/10-1/7 of the height of the welding strip piece.

Optionally, the width of the first groove is 1/100-1/80 of the length of the welding area.

Optionally, the length of the first groove is 1/2-2/3 of the width of the welding area.

Optionally, the number of the first grooves is a plurality.

Optionally, the edge of either side of the welding area is provided with a plurality of first grooves, and the first grooves are uniformly distributed at intervals in the extending direction parallel to the welding strip substrate.

Optionally, in the extending direction of the solder strip substrate, a distance between any adjacent first grooves is 0.8mm-1.2mm.

Optionally, the solder strip substrate is recessed towards the solder strip substrate in the part area facing away from the curved surface to form a second groove, the extending direction of the second groove is perpendicular to the extending direction of the solder strip substrate, and the second groove is communicated with the first groove.

Optionally, the depth of the second groove is 7/40-9/40 of the height of the solder strip.

Optionally, the width of the second groove is 1/800-3/800 of the length of the welding area.

Optionally, the number of the second grooves is a plurality, and the plurality of the second grooves are uniformly distributed at intervals in the extending direction parallel to the solder strip substrate.

Optionally, the spacing between any adjacent second slots is equal to the spacing between any adjacent first slots.

Optionally, the tangential plane of the second groove coincides with the tangential plane of the first groove.

Optionally, the welding area comprises a first welding area and a second welding area; the connecting area is connected with the first welding area and the second welding area; the first slot comprises a first subslot and a second subslot; the first welding area comprises a first welding plane and a first back curved surface protruding outwards relative to the first welding plane, the first welding plane is suitable for facing one of the adjacent battery pieces and contacting with the battery piece, and the first back curved surface is suitable for facing away from the battery piece; the second welding area comprises a second welding plane and a second back curved surface protruding outwards relative to the second welding plane, the second welding plane is suitable for facing the other battery piece in the adjacent battery pieces and contacting with the other battery piece, and the second back curved surface is suitable for facing away from the other battery piece; the welding strip base body is recessed towards the welding strip base body in the edge area of the first welding plane to form a first sub-groove, and the wall surface of the first sub-groove is connected with the first back curved surface; the welding strip base body is recessed towards the welding strip base body in the edge area of the second welding plane to form a second sub-groove, and the wall surface of the second sub-groove is connected with the second back curved surface.

Optionally, the connection area has opposite first face and second face, first face is located first back of body curved surface with between the second welding plane, the second face is located first welding plane with between the second back of body curved surface, the radian of first face is from first back of body curved surface to the direction of second welding plane gradually decreases to zero, the radian of second face is from first back of body curved surface to the direction of second welding plane gradually increases by zero.

The utility model also provides a composite film for packaging a solar cell without a main grid, wherein both the front surface and the back surface of the solar cell without the main grid are provided with fine grids and only the fine grids, and the composite film comprises: the bearing film is provided with a plurality of grooves on one side surface; in the above welding strip, the welding area is located on one side surface of the carrier film or in the groove, the welding area is used for collecting the current of the fine grid, and the back curved surface faces to the opening of the groove.

The present utility model also provides a battery pack comprising: a plurality of battery pieces; the welding strip piece is connected with adjacent battery pieces in series; the welding plane is welded on one side surface of the battery piece; the first groove is filled with a welding film.

Optionally, the welding area comprises a first welding area and a second welding area; for any adjacent first battery piece and second battery piece, the first welding area is welded with the light receiving surface of the first battery piece, and the second welding area is welded with the backlight surface of the second battery piece.

The technical scheme of the utility model has the following advantages:

the welding strip piece comprises a welding area and a connecting area, wherein the surface of the welding strip base positioned in the welding area comprises a welding plane and a back curved surface protruding outwards relative to the welding plane, the welding plane is suitable for facing towards the battery piece and contacting with the battery piece, the back curved surface is suitable for facing away from the battery piece, and the welding strip piece is in surface contact with the battery piece, so that the welding flat area between the welding strip piece and the battery piece is large, and the phenomena of insufficient welding tension and insufficient cold welding can be avoided; the back curved surface is positioned at one side of the welding plane, which is back to the battery piece; the welding strip substrate is recessed towards the welding strip substrate in the edge area of the welding plane to form a first groove, the wall surface of the first groove is connected with the back curved surface, the first groove can improve friction between the welding strip piece and the battery piece, and further, offset welding caused by sliding of the welding strip piece in the welding process can be avoided, and therefore the welding precision of the first groove can be improved; the welding film covers the outer surface of the welding strip substrate of the welding area, and in the welding process, the welding film connected with the welding plane on the back curved surface can be melted and flows into the first groove along the back curved surface, so that the welding strength between the welding strip piece and the battery piece is further enhanced. In conclusion, accurate welding and high binding force can be achieved between the welding strip piece and the battery piece.

Further, the number of the first grooves is a plurality of; preferably, the edge of either side of the welding zone is provided with a plurality of first grooves which are uniformly distributed at intervals in the extending direction parallel to the welding strip matrix; the friction between the welding strip piece and the battery piece can be further improved through the plurality of first grooves, and further, the welding strip piece can be prevented from being subjected to partial welding in the welding process, and the welding precision is improved.

Further, the welding strip base body is recessed towards the welding strip base body in the part area of the back curved surface to form a second groove, and the extending direction of the second groove is perpendicular to the extending direction of the welding strip base body; when grabbing the welding strip piece, the friction force between the welding strip clamping claw and the welding strip piece can be increased through the second groove, the welding strip piece is prevented from falling off in the process of grabbing the welding strip piece, and the welding efficiency is improved.

Further, the second groove is communicated with the first groove, and in the welding process, the welding film in the second groove melts and flows into the first groove along the second groove, so that the welding strength between the welding strip piece and the battery piece can be enhanced.

Further, the connection area has relative first face and second face, first face is located first back curved surface with between the second welding plane, the second face is located first welding plane with between the second back curved surface, the radian of first face is from first back curved surface to the direction of second welding plane gradually decreases to zero, the radian of second face is from first back curved surface to the direction of second welding plane gradually increases by zero. The connecting area does not need to be flattened by a flattening mechanism, so that the manufacturing cost is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a top view of a solder strip member according to an embodiment of the present utility model;

FIG. 2 is a side view of a solder strip member according to an embodiment of the present utility model;

FIG. 3 is an enlarged view of a portion of a solder strip according to an embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a battery assembly according to an embodiment of the present utility model;

fig. 5 is a side view of a battery assembly according to an embodiment of the present utility model.

Reference numerals illustrate:

b-a back curved surface; c1-a first tank; c2-a second tank; j-welding plane; an L-junction region; m-welding a film; m1-a first welding zone; m2-a second bonding region; 100-a first battery piece; 101-second cell

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

Example 1

The present embodiment provides a solder strip member adapted to connect adjacent battery pieces in series, and referring to fig. 1, 2 and 3 in combination, including: the welding strip substrate comprises a welding area and a connecting area, the surface of the welding strip substrate positioned in the welding area comprises a welding plane J and a back curved surface B which is outwards protruded relative to the welding plane J, the welding plane J is suitable for facing towards the battery piece and contacting with the battery piece, and the back curved surface B is suitable for facing away from the battery piece; the welding strip base body is recessed towards the welding strip base body in the edge area of the welding plane J to form a first groove C1, and the wall surface of the first groove C1 is connected with the back curved surface B; and the welding film M coats the outer surface of the welding strip matrix of the welding zone.

The welding strip member provided by the embodiment, the welding strip base body comprises a welding area and a connecting area, the surface of the welding strip base body positioned in the welding area comprises a welding plane J and a back curved surface B protruding outwards relative to the welding plane J, the welding plane J is suitable for facing towards the battery piece and contacting with the battery piece, the back curved surface B is suitable for facing away from the battery piece, and the welding strip member is in surface contact with the battery piece, so that the welding flat area between the welding strip member and the battery piece is large, and the phenomena of insufficient welding tension and insufficient cold welding can be avoided; the back curved surface B is positioned at one side of the welding plane J, which is back to the battery piece; the welding strip base body is recessed towards the welding strip base body in the edge area of the welding plane J to form a first groove C1, the wall surface of the first groove C1 is connected with the back curved surface, the first groove C1 can improve friction between the welding strip piece and the battery piece, and further, offset welding caused by sliding of the welding strip piece in the welding process can be avoided, and therefore the welding precision of the first groove C1 can be improved; the welding film M coats the outer surface of the welding strip substrate of the welding zone, and in the welding process, the welding film connected with the welding plane J on the back curved surface B can melt and flow into the first groove C1 along the back curved surface, so that the welding strength between the welding strip piece and the battery piece is further enhanced. In conclusion, accurate welding and high binding force can be achieved between the welding strip piece and the battery piece. Compared with the round wire bonding strip in the prior art, the bonding strip piece provided by the embodiment is not easy to slide to cause the phenomenon of cold joint and bonding strip piece deviation.

In one embodiment, the solder strip substrate is in a strip shape, the length direction of the first groove C1 is perpendicular to the extending direction of the solder strip substrate, and the length direction of the first groove C1 is the extending direction of the first groove C1; in another embodiment, the length direction of the first groove is not perpendicular to the extending direction of the welding strip substrate, and the length direction of the first groove is not perpendicular to the extending direction of the welding strip substrate, so that the length of the first groove can be increased, friction between the welding strip piece and the battery piece is improved, and welding precision is improved.

In one embodiment, the welding film M is any two or more metal alloys selected from tin, lead, bismuth, indium and silver, and the material of the welding area includes copper.

In one embodiment, the cross-sectional pattern of the first groove C1 perpendicular to the longitudinal direction of the first groove C1 includes a triangle, and the base of the triangle is located on the same side as the welding plane J. The cross section graph of the first groove C1 in the length direction perpendicular to the first groove C1 is triangular, so that friction between the welding strip piece and the battery piece can be improved, the welding film on the back curved surface can be completely filled in the first groove after being melted, and welding strength between the welding strip piece and the battery piece is enhanced.

In one embodiment, the first groove C1 has an acute angle between its length and its direction of extension, which is in the range of 30 ° to 40 °, for example 35 °.

In one embodiment, the height of the first groove C1 is 1/10-1/7, such as 1/8, of the height of the solder strip; if the height of the first groove is less than 1/10 of the height of the welding strip piece, the difficulty of forming the first groove is increased, and the phenomenon that the welding strip piece slides in the welding process to cause uneven welding is avoided; if the height of the first groove is greater than 1/7 of the height of the welding strip piece, the first groove is not easy to be completely filled after the welding film on the back curved surface connected with the welding plane is melted in the welding process, so that the effect of enhancing the welding strength between the welding strip piece and the battery piece is not obvious.

In one embodiment, the width of the first groove C1 is 1/100-1/80, such as 9/800, of the length of the weld zone; if the width of the first groove is smaller than 1/100 of the length of the welding area, the difficulty of forming the first groove is increased, and the phenomenon that the welding strip piece slides in the welding process to cause the uneven welding effect is not obvious is avoided; if the width of the first groove is greater than 1/80 of the length of the welding area, the first groove is not easy to be completely filled after the welding film on the back curved surface connected with the welding plane is melted in the welding process, so that the effect of enhancing the welding strength between the welding strip piece and the battery piece is not obvious.

In one embodiment, the length of the first groove C1 is 1/2-2/3 of the width of the welding zone. In a specific embodiment, the length of the first groove C1 is 60 μm to 70 μm, for example 65 μm; if the length of the first groove is smaller than 60 μm, the difficulty of forming the first groove is increased, and the phenomenon that the welding strip piece slides in the welding process to cause the uneven welding effect is not obvious is avoided; if the length of the first groove is greater than 70 μm, the first groove is not easy to be completely filled after the welding film on the back curved surface connected with the welding plane is melted in the welding process, so that the effect of enhancing the welding strength between the welding strip piece and the battery piece is not obvious.

In one embodiment, the number of the first grooves C1 is several. The friction between the welding strip piece and the battery piece can be further improved through the plurality of first grooves, and further, the welding strip piece can be prevented from being subjected to partial welding in the welding process, and the welding precision is improved.

In one embodiment, the edge of either side of the bonding pad has a plurality of first grooves which are uniformly spaced apart in a direction parallel to the extension of the bonding pad substrate.

In one embodiment, the spacing between any adjacent first grooves in the direction of extension of the solder strip substrate is 0.8mm-1.2mm, for example 1mm; if the spacing between any adjacent first grooves is less than 0.8mm, the difficulty of forming the first grooves is increased; if the distance between any adjacent first grooves is larger than 1.2mm, the effect of preventing the welding strip piece from being deviated in the welding process is not obvious.

In one embodiment, the solder strip substrate is recessed toward the solder strip substrate in the part area of the back surface to form a second groove C2, and the extending direction of the second groove C2 is perpendicular to the extending direction of the solder strip substrate. When grabbing the welding strip piece, the friction force between the welding strip clamping claw and the welding strip piece can be increased by the second groove C2, the welding strip piece is prevented from falling off in the process of grabbing the welding strip piece, and the welding efficiency is improved.

In one embodiment, the second tank C2 communicates with the first tank C1; during the welding process, the welding film in the second groove melts and flows into the first groove along the second groove, so that the welding strength between the welding strip piece and the battery piece can be enhanced.

In one embodiment, the depth of the second groove C2 is 7/40-9/40, such as 8/40, of the height of the solder strip; if the depth of the second groove is less than 7/40 of the height of the welding strip, the effect of preventing the welding strip from falling off and improving the welding efficiency is not obvious in the process of grabbing the welding strip; if the depth of the second groove is greater than 9/40 of the height of the welding strip, the depth of the second groove is too deep, and the capacity of improving the current collection of the welding strip is weak.

In one embodiment, the width of the second groove C2 is 1/800-3/800, such as 1/400, of the length of the weld zone; if the width of the second groove is smaller than 1/800 of the length of the welding area, the effect of preventing the welding strip from falling off and improving the welding efficiency is not obvious in the process of grabbing the welding strip; if the width of the second groove is greater than 3/800 of the length of the weld zone, the ability to increase the current collection capacity of the strap is weaker.

In one embodiment, the number of the second grooves C2 is a plurality, and the plurality of the second grooves are uniformly spaced apart in a direction parallel to the extending direction of the solder strip substrate.

In one embodiment, the spacing between any adjacent second slots is equal to the spacing between any adjacent first slots, and in a particular embodiment, the spacing between any adjacent second slots is 0.8mm to 1.2mm, such as 1.0mm; if the spacing between any adjacent second slots is less than 0.8mm, then the number of second slots is excessive, possibly resulting in a weaker ability to increase the current collection capacity of the solder strip; if the distance between any two adjacent second grooves is larger than 1.2mm, the effect of preventing the solder strip from falling off in the process of grabbing the solder strip is not obvious.

In one embodiment, the tangent plane of the second slot coincides with the tangent plane of the first slot.

In one embodiment, with continued reference to FIG. 1, the weld zone includes a first weld zone and a second weld zone; the connecting area L is connected with the first welding area and the second welding area; the first slot comprises a first subslot and a second subslot; the first welding area comprises a first welding plane and a first back curved surface protruding outwards relative to the first welding plane, the first welding plane is suitable for facing one of the adjacent battery pieces and contacting with the battery piece, and the first back curved surface is suitable for facing away from the battery piece; the second welding area comprises a second welding plane and a second back curved surface protruding outwards relative to the second welding plane, the second welding plane is suitable for facing the other battery piece in the adjacent battery pieces and contacting with the other battery piece, and the second back curved surface is suitable for facing away from the other battery piece; the welding strip base body is recessed towards the welding strip base body in the edge area of the first welding plane to form a first sub-groove, and the wall surface of the first sub-groove is connected with the first back curved surface; the welding strip base body is recessed towards the welding strip base body in the edge area of the second welding plane to form a second sub-groove, and the wall surface of the second sub-groove is connected with the second back curved surface.

In one embodiment, the material of the connection region L comprises copper.

In one embodiment, the connection area L has a first surface and a second surface opposite to each other, the first surface is located between the first back curved surface and the second welding plane, the second surface is located between the first welding plane and the second back curved surface, the radian of the first surface gradually decreases from the first back curved surface to the second welding plane, and the radian of the second surface gradually increases from zero from the first back curved surface to the second welding plane. The connecting part does not need to be flattened by a flattening mechanism, so that the manufacturing cost is reduced.

In one embodiment, the height of the connection zone L is 0.13mm-0.16mm, for example 0.15mm.

The welding strip piece provided by the embodiment, the welding strip base body comprises a welding area and a connecting area, the surface of the welding strip base body located at the welding area comprises a welding plane J and a back curved surface B protruding outwards relative to the welding plane J, the welding plane J is suitable for facing towards the battery piece and contacting with the battery piece, the back curved surface B is suitable for facing away from the battery piece, and the welding strip piece is in surface contact with the battery piece, so that the risk of hidden cracking and fragments of the battery piece can be reduced, and meanwhile, the battery piece can be flaked. Compared with the round wire welding strip in the prior art, the cost of the welding strip provided by the embodiment is half of that of the round wire welding strip in the prior art, so that the cost of the welding strip provided by the embodiment is lower.

The welding strip member provided by the embodiment has a wide application range, and is not only suitable for series welding between common battery pieces with main grids, but also particularly suitable for series welding between battery pieces without main grids. In one embodiment, the surface of the battery piece comprises and only comprises a plurality of thin grid lines which are arranged in parallel at intervals; or the surface of the battery piece comprises a plurality of thin grid lines which are arranged in parallel at intervals and a main grid line which is arranged vertically to the thin grid lines and is connected with the thin grid lines.

The solder strip is also suitable for different types of battery pieces. The cell may include a PERC (emitter and back passivation solar cell, passivated Emitter and Rear Cell), TOPCon (tunnel oxide passivation contact, tunnel Oxide Passivated Contact) solar cell, or HJT (heterojunction, hetero Junction with intrinsic Thin layer) solar cell.

Example 2

The embodiment provides a composite film for packaging a solar cell without a main grid, wherein both the front surface and the back surface of the solar cell without the main grid are provided with thin grids and only provided with thin grids, and the composite film comprises: the carrier film is used for carrying the welding strip piece in the embodiment 1, and preferably a plurality of grooves are formed in one side surface of the carrier film; the bonding pad in the bonding pad of embodiment 1 is located on one side surface of the carrier film or in the groove, the bonding pad is used for collecting the current of the fine grid, and the back surface faces the opening of the groove.

In one embodiment, the carrier films include a plurality of, and a plurality of carrier films are arranged at intervals in an extending direction of the welding strip, and the welding zone of the welding strip includes a first welding zone and a second welding zone, wherein the first welding zone includes a first welding plane and a first back curved surface protruding outwards relative to the first welding plane, the second welding zone includes a second welding plane and a second back curved surface protruding outwards relative to the second welding plane, and for any adjacent first carrier film and second carrier film, the first carrier film is located on a side surface of the first back curved surface, which is away from the first welding plane, and the second carrier film is located on a side surface of the second back curved surface, which is away from the second welding plane.

In one embodiment, the width of the fine grid is 0.03mm-0.05mm, for example 0.04mm, so that the width of the fine grid is smaller, the surface of the welding strip base located in the welding area comprises a welding plane and a back curved surface protruding outwards relative to the welding plane, the welding plane is used for being contacted with the battery piece towards the battery piece, the welding strip piece is contacted with the battery piece in a surface mode, the welding plane area between the welding strip piece and the battery piece is larger, the welding strip piece is conveniently fixed on the battery piece, the welding precision of the welding strip piece and the battery piece is improved, and insufficient welding tension and cold welding phenomena can be avoided.

Example 3

The present embodiment provides a battery pack including: a plurality of battery pieces; the solder strip of embodiment 1, the solder strip connecting adjacent battery cells in series; the welding plane is welded and connected with the surface of the battery piece; the first groove is filled with a welding film.

In one embodiment, referring to fig. 4 and 5 in combination, the bonding pad includes a first bonding pad M1 and a second bonding pad M2; the welding strip piece further comprises a connecting area L for connecting the first welding area M1 and the second welding area M2; for any adjacent first and second battery pieces 100 and 101, the first welding area M1 is welded to the light receiving surface of the first battery piece 100, and the second welding area M2 is welded to the backlight surface of the second battery piece 101. Specifically, the first welding area comprises a first welding plane and a first back curved surface protruding outwards relative to the first welding plane, the first welding plane is used for facing the light receiving surface of one of the adjacent battery pieces and contacting with the battery piece, and the first back curved surface is positioned on one side of the first welding plane, facing away from the battery piece; the second welding area comprises a second welding plane and a second back curved surface protruding outwards relative to the second welding plane, the second welding plane is used for facing the backlight surface of the other battery piece in the adjacent battery pieces and contacting with the battery pieces, and the second back curved surface is positioned on one side of the second welding plane, facing away from the battery pieces; a first sub-groove is formed by recessing from a partial area of the first welding plane towards the welding strip substrate, a welding film is filled in the first sub-groove, and the inner wall surface of the first sub-groove is connected with the first back curved surface close to the first welding plane; and a second subslot is formed by recessing from a partial area of the second welding plane towards the welding strip substrate, a welding film is filled in the first subslot, and the inner wall surface of the second subslot is connected with the second back curved surface close to the second welding plane. The welding film in the first sub-groove and the welding film in the second sub-groove can improve connectivity between the welding strip piece and the battery piece.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims (21)

1. A solder strip adapted to connect adjacent battery cells in series, comprising:

the welding strip substrate comprises a welding area and a connecting area, the surface of the welding strip substrate positioned in the welding area comprises a welding plane and a back curved surface which is outwards protruded relative to the welding plane, the welding plane is suitable for facing towards the battery piece and contacting with the battery piece, and the back curved surface is suitable for facing away from the battery piece;

the welding strip substrate is recessed towards the welding strip substrate in the edge area of the welding plane to form a first groove, and the wall surface of the first groove is connected with the back curved surface;

and the welding film coats the outer surface of the welding strip matrix of the welding zone.

2. The solder strip member according to claim 1, wherein the solder strip base is in a strip shape, and the length direction of the first groove is perpendicular or non-perpendicular to the extending direction of the solder strip base, and the length direction of the first groove is the extending direction of the first groove.

3. The solder strip according to claim 1, wherein the cross-sectional pattern of the first groove in a direction perpendicular to the length of the first groove comprises a triangle, the base of the triangle being on the same side as the solder plane.

4. The solder strip member of claim 1, wherein the first slot has an acute included angle between a length direction of the first slot and an extension direction of the solder strip body, the acute included angle being in the range of 30 ° to 40 °.

5. The solder strip of claim 1, wherein the height of the first slot is 1/10-1/7 of the height of the solder strip.

6. The solder strip of claim 1, wherein the width of the first slot is 1/100-1/80 of the length of the solder pad.

7. The solder strip of claim 1, wherein the length of the first slot is 1/2-2/3 of the width of the solder pad.

8. The solder strip of claim 1, wherein the number of first slots is a number.

9. The solder strip member of claim 1 wherein the edge on either side of the solder land has a plurality of first grooves spaced evenly in a direction parallel to the extension of the solder strip base.

10. The solder strip member according to claim 1, wherein a spacing between any adjacent ones of the first grooves in an extending direction of the solder strip base is 0.8mm to 1.2mm.

11. The solder strip member according to claim 1, wherein the solder strip base is recessed in the portion of the back surface toward the solder strip base to form a second groove, the second groove extending in a direction perpendicular to the direction of extension of the solder strip base, the second groove communicating with the first groove.

12. The solder strip of claim 11, wherein the depth of the second groove is 7/40-9/40 of the height of the solder strip.

13. The solder strip of claim 11, wherein the width of the second slot is 1/800-3/800 of the length of the solder pad.

14. The solder strip member as in claim 11, wherein the number of the second grooves is plural, and the plural second grooves are arranged at regular intervals in a direction parallel to an extending direction of the solder strip base body.

15. The solder strip of claim 11, wherein the spacing between any adjacent second slots is equal to the spacing between any adjacent first slots.

16. The solder strip of claim 11, wherein a tangent plane of the second slot coincides with a tangent plane of the first slot.

17. The solder strip member of claim 1, wherein the solder areas comprise a first solder area and a second solder area; the connecting area is connected with the first welding area and the second welding area; the first slot comprises a first subslot and a second subslot;

the first welding area comprises a first welding plane and a first back curved surface protruding outwards relative to the first welding plane, the first welding plane is suitable for facing one of the adjacent battery pieces and contacting with the battery piece, and the first back curved surface is suitable for facing away from the battery piece;

the second welding area comprises a second welding plane and a second back curved surface protruding outwards relative to the second welding plane, the second welding plane is suitable for facing the other battery piece in the adjacent battery pieces and contacting with the other battery piece, and the second back curved surface is suitable for facing away from the other battery piece;

the welding strip base body is recessed towards the welding strip base body in the edge area of the first welding plane to form a first sub-groove, and the wall surface of the first sub-groove is connected with the first back curved surface;

the welding strip base body is recessed towards the welding strip base body in the edge area of the second welding plane to form a second sub-groove, and the wall surface of the second sub-groove is connected with the second back curved surface.

18. The strap of claim 17 wherein the connecting region has opposed first and second faces, the first face being located between the first and second oppositely facing curved surfaces, the second face being located between the first and second oppositely facing curved surfaces, the curvature of the first face gradually decreasing from zero in the direction from the first oppositely facing curved surface to the second welding plane, the curvature of the second face gradually increasing from zero in the direction from the first oppositely facing curved surface to the second welding plane.

19. A composite film for packaging a solar cell without a main grid, the front and back surfaces of the solar cell without a main grid having fine grids and only having fine grids, comprising:

the bearing film is provided with a plurality of grooves on one side surface;

the solder strip of any of claims 1 to 18, wherein the land is located on a side surface of the carrier film or within the recess, the land being for collecting current from the fine grid, the back surface facing the opening of the recess.

20. A battery assembly, comprising:

a plurality of battery pieces;

the solder strip of any of claims 1 to 18, which connects adjacent ones of the battery cells in series;

the welding plane is welded and connected with the surface of the battery piece;

the first groove is filled with a welding film.

21. The battery assembly of claim 20, wherein the weld zone comprises a first weld zone and a second weld zone;

for any adjacent first battery piece and second battery piece, the first welding area is welded with the light receiving surface of the first battery piece, and the second welding area is welded with the backlight surface of the second battery piece.