CN213716919U

CN213716919U - Battery string and photovoltaic module

Info

Publication number: CN213716919U
Application number: CN202022352092.3U
Authority: CN
Inventors: 李子峰; 徐琛; 吴兆; 解俊杰
Original assignee: Longi Green Energy Technology Co Ltd
Current assignee: Longi Green Energy Technology Co Ltd
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2021-07-16
Anticipated expiration: 2030-10-20

Abstract

The utility model provides a battery cluster and photovoltaic module relates to the photovoltaic technology field. The battery string comprises a plurality of battery pieces, a front interconnection strip and a back interconnection strip; the battery piece includes: the power generation device comprises a power generation unit, a front electrode, a back electrode, a side insulating layer and a side conductive piece; the side surface insulating layer is positioned between the side surface conductive piece and the side surface of the power generation unit; the interconnection bar comprises conductive segments and insulating segments which are distributed at intervals; the first side surface conductive piece of one battery piece is electrically contacted with the second side surface conductive piece of the adjacent battery piece, the conductive section of the front interconnection strip is electrically connected with the front electrode of one battery piece and the first side surface conductive piece, the conductive section of the back interconnection strip is electrically connected with the back electrode of the adjacent battery piece and the second side surface conductive piece, and the adjacent battery pieces are connected in series. The interconnecting strips do not need to be bent, and hidden cracks are reduced. And an interconnection bar just extends to the other end from the one end of battery cluster, need not the centre and cuts, and the counterpoint is simple, and simple process, production efficiency is high.

Description

Battery string and photovoltaic module

Technical Field

The utility model relates to a photovoltaic technology field especially relates to a battery cluster and photovoltaic module.

Background

At present, the battery string is usually formed by bending a conductive interconnection member, and the conductive interconnection member extends from a light-facing surface of one battery piece to a backlight surface of another battery piece so as to connect adjacent battery pieces in series.

However, the conductive interconnection piece extends from the light-facing surface of one cell to the backlight surface of another cell, a large space needs to be left between the cells, and the space position cannot perform photoelectric conversion, and meanwhile, the bending position of the conductive interconnection piece is easy to generate hidden crack and other problems, so that the photoelectric conversion efficiency is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model provides a battery cluster and photovoltaic module aims at solving in the battery cluster that the interval is big between the battery piece, electrically conductive interconnection spare department of bending easily produces the problem of latent splitting.

According to a first aspect of the present invention, there is provided a battery string, comprising a plurality of battery pieces and an interconnection bar extending from one end of the battery string to the other end; the interconnection strips comprise front interconnection strips positioned on the light-facing surfaces of the plurality of battery pieces and back interconnection strips positioned on the back light surfaces of the plurality of battery pieces;

the battery piece includes: the power generation device comprises a power generation unit, a front electrode, a back electrode, a side insulating layer and a side conductive piece; the power generation unit is provided with a light facing surface, a backlight surface and a side surface, wherein the light facing surface and the backlight surface are oppositely arranged, and the side surface is connected with the light facing surface and the backlight surface; the front electrode is positioned on the light facing surface of the power generation unit; the back electrode is positioned on a backlight surface of the power generation unit; the side surface insulating layer is positioned between the side surface conductive piece and the side surface of the power generation unit; the side surface conductive pieces comprise a first side surface conductive piece and a second side surface conductive piece which are positioned on different sides of the power generation unit; a first insulation gap is formed between the first side surface conductive piece and the second side surface conductive piece; a second insulation gap is formed between the first side surface conductive piece and the back electrode; a third insulation gap is formed between the second side surface conductive piece and the front electrode; the interconnection bar is provided with conductive segments and insulating segments which are distributed at intervals; the first side surface conductive piece of one battery piece is electrically contacted with the second side surface conductive piece of the adjacent battery piece, the conductive section of the front surface interconnection strip is electrically connected with the front surface electrode of one battery piece and the first side surface conductive piece, and the conductive section of the back surface interconnection strip is electrically connected with the back surface electrode of the adjacent battery piece and the second side surface conductive piece so as to connect the adjacent battery pieces in series; the insulating section of the front interconnection bar is opposite to the third insulating gap, and the insulating section of the back interconnection bar is opposite to the second insulating gap.

The utility model discloses among the embodiment, second insulation clearance has between first side electrically conductive piece and the back electrode, third insulation clearance has between second side electrically conductive piece and the front electrode, side electrically conductive piece is including the electrically conductive piece of first side and the electrically conductive piece of second side that are located the different sides of power generation unit, first insulation clearance has between the electrically conductive piece of first side and the electrically conductive piece of first side, the side insulating layer that is located between the side electrically conductive piece of side and power generation unit can avoid power generation unit and the electrically conductive connection of electrically conductive piece of side, can avoid the inside short circuit of battery. The first side surface conductive piece of one battery piece is electrically contacted with the second side surface conductive piece of the adjacent battery piece, so that no space or small space exists between the adjacent battery pieces. The conductive section of the front interconnection strip is conductively connected with the front electrode of one battery piece and the first side surface conductive piece, the conductive section of the back interconnection strip is conductively connected with the back electrode of the adjacent battery piece and the second side surface conductive piece so as to connect the adjacent battery pieces in series, the insulating section of the front interconnection strip is opposite to the third insulating gap between the second side surface conductive piece and the front electrode, and the insulating section of the back interconnection strip is opposite to the second insulating gap between the first side surface conductive piece and the back electrode, so that the interconnection strip does not need to be bent from the light-facing surface of the battery piece to the backlight surface of the battery piece, the stress concentration problem caused by bending of the conductive interconnection piece is reduced, and hidden cracks are reduced. And an interconnection bar just extends to the other end from the one end of battery cluster, need not the centre and cuts, and the counterpoint is simple, and simple process, production efficiency is high.

Optionally, a conductive connection layer is arranged between the first side conductive piece of one cell and the second side conductive piece of the adjacent cell;

and/or a conductive connecting layer is arranged between the front electrode and the first side conductive piece;

and/or a conductive connecting layer is arranged between the conductive section of the front interconnection strip and the front electrode;

and/or a conductive connecting layer is arranged between the conductive section of the front interconnection bar and the first side conductive piece;

and/or a conductive connecting layer is arranged between the back electrode and the second side surface conductive piece;

and/or a conductive connecting layer is arranged between the conductive segment of the back interconnection strip and the back electrode;

and/or a conductive connecting layer is arranged between the conductive section of the back interconnection bar and the second side conductive piece.

Optionally, an electrical isolator is filled in the second insulating gap, and/or an electrical isolator is filled in the third insulating gap.

Optionally, the conductive connection layer is at least one of a solder conductive connection layer, a conductive adhesive connection layer, and a low-melting-point metal connection layer.

Optionally, the low melting point metal connection layer comprises a tin layer.

Optionally, the interconnection bar includes a strip-shaped extended insulating base, and a conductive bar fixed on the insulating base; the conductive strip is positioned on the conductive segment;

the conductive strips are exposed close to the surface of the battery piece.

Optionally, the insulating matrix semi-surrounds the conductive strip; or, the insulating matrix is positioned on one side of the conductive strip.

Optionally, the interconnection bar further comprises an insulating bar fixed on the insulating base; the insulating strip is located in the insulating section.

Optionally, the conductive bar is clamped on the insulating base, or the conductive bar is bonded on the insulating base.

Optionally, the insulating strip and the insulating base are integrally formed.

Optionally, the conductive bar is provided with a welding alloy layer on the surface close to the battery piece.

Optionally, the cross section of the front interconnection bar is triangular or circular; and/or a light-facing surface of the front interconnection strip is provided with a light-reflecting structure.

Optionally, the power generation unit includes a PN junction.

Optionally, the conductive strip is a solder strip.

According to the utility model discloses a second aspect still provides a photovoltaic module, include: any of the foregoing battery strings.

The photovoltaic module has the same or similar beneficial effects as the battery string.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 shows a schematic structural diagram of a battery string according to an embodiment of the present invention;

fig. 2 shows a schematic structural diagram of a battery plate according to an embodiment of the present invention;

fig. 3 shows a schematic top view of a battery string in an embodiment of the invention;

fig. 4 shows a schematic bottom view of a battery string according to an embodiment of the present invention;

fig. 5 is a schematic view of a partial structure of a battery string according to an embodiment of the present invention;

fig. 6 is a schematic partial structure diagram of another battery string according to an embodiment of the present invention;

fig. 7 is a schematic partial structure diagram of another battery string according to an embodiment of the present invention;

fig. 8 shows a schematic structural diagram of another battery string according to an embodiment of the present invention;

fig. 9 shows a schematic top view of another battery string in an embodiment of the invention;

fig. 10 shows a schematic bottom view of another battery string according to an embodiment of the present invention;

fig. 11 shows a schematic partial structure diagram of an interconnection bar according to an embodiment of the present invention;

fig. 12 shows a partial schematic structure of another interconnect strip in an embodiment of the present invention;

fig. 13 is a partial schematic structural view of another interconnection bar according to an embodiment of the present invention;

fig. 14 shows a schematic view of an insulating matrix according to an embodiment of the invention;

fig. 15 shows a schematic structural view of another insulating matrix in an embodiment of the invention;

fig. 16 is a schematic structural diagram of another battery string according to an embodiment of the present invention.

Description of the figure numbering:

1-N-type silicon substrate, 2-P-type silicon, 301-main gate, 302-fine gate, 61-first side conductive piece, 62-second side conductive piece, 401-front interconnection bar, 411-insulating segment of front interconnection bar, 412-conductive segment of front interconnection bar, 402-back interconnection bar, 413-conductive segment of back interconnection bar, 414-insulating segment of back interconnection bar, 303-back electrode, 5-side insulating layer, 801-conductive connection layer, 901-electrical isolator, 421-insulating bar, 422-insulating base, 423-conductive bar.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the embodiment of the present invention, the battery cell may be a crystalline silicon battery cell, a stacked battery, or the like. The power generation unit is a portion of the cell sheet that generates and separates holes and electrons. The shape of the power generation element may be a polygonal sheet shape, a film shape, or the like.

Alternatively, the power generation unit may be a battery unit of a stacked battery unit. For example, the power generation unit may be a combination of a lower layer cell and an upper layer cell of a laminate cell. The upper battery unit in the laminated battery can be a perovskite battery piece. The band gap width of the upper battery cell is larger than that of the lower battery cell.

The power generating unit may employ any cell technology, such as a front PN junction or a back PN junction, such as a deep junction or a shallow junction, such as an Al-BSF structure, a PERx structure (PERC, PERT, PERL, PERF), an SHJ structure, a TOPCon structure, a DASH structure, or a stacked cell structure based on crystalline silicon cells.

Referring to fig. 1, fig. 1 shows a schematic structural diagram of a battery string according to an embodiment of the present invention. The battery string comprises a plurality of battery pieces and interconnection strips extending from one end of the battery string to the other end of the battery string. Namely, the interconnection bar is full-length, the length of the interconnection bar is basically consistent with that of the battery string, and then one interconnection bar extends from one end of the battery string to the other end without middle truncation, so that the alignment is simple, the process is simple, and the production efficiency is high. The number of battery pieces included in the battery string is not particularly limited.

The interconnection bars comprise front interconnection bars 401 positioned on the light-facing surfaces of the plurality of battery pieces and back interconnection bars 402 positioned on the back light surfaces of the plurality of battery pieces.

Fig. 2 shows a schematic structural diagram of a battery plate in an embodiment of the present invention. Referring to fig. 1 and 2 in combination, the battery plate includes: a power generating unit, a front electrode, a back electrode 302, a side insulating layer 5, and a side conductive member. Alternatively, as shown in fig. 1, the power generation unit may include a PN junction. In fig. 1, 1 may be an N-type silicon substrate, 2 may be a P-type silicon substrate, and 1 and 2 form a PN junction. The silicon substrate may be a monocrystalline silicon material, a polycrystalline silicon material, a microcrystalline silicon material, or the like. The side surface conductive members include a first side surface conductive member 61 and a second side surface conductive member 62 located at different sides of the power generation unit with a first insulation gap between the first side surface conductive member 61 and the second side surface conductive member 62. The side surfaces on which first side surface conductive member 61 and second side surface conductive member 62 are respectively located, and the relative positional relationship therebetween are not particularly limited. As shown in fig. 1, the side surface conductive members include a first side surface conductive member 61 positioned at the right side of the power generation unit and a second side surface conductive member 62 positioned at the left side of the power generation unit. There is a first insulation gap between the left second side conductor 62 and the right first side conductor 61. The size of the first insulation gap is set according to actual needs.

The power generation unit is provided with a light facing surface, a backlight surface and a side surface, wherein the light facing surface and the backlight surface are oppositely arranged, and the side surface is connected with the light facing surface and the backlight surface. The number of sides included in the power generation unit is not particularly limited. For example, if the power generation unit is a rectangular parallelepiped, the power generation unit includes 4 side surfaces. If the power generation unit is a hexagonal prism, the power generation unit includes 6 side surfaces. The front electrode is located on the light facing side of the power generating unit and the back electrode 303 is located on the backlight side of the power generating unit. The front electrode and the back electrode 303 have opposite polarities. For example, the front electrode may be a positive electrode, and the back electrode 303 may be a negative electrode. Both the front and back electrodes 303 may be formed of a main gate and a fine gate. The present invention is not particularly limited to this. The pattern of the fine grid is not limited, and may be linear, forked, or any pattern, for example. The material of the front electrode and the back electrode 303 is not particularly limited. The front electrode and the back electrode 303 may also be both gate lines, for example, the front electrode is a front gate line, and is manufactured by using a silver paste screen printing, and adopting an MBB structure without division of a main gate and a fine gate.

It should be noted that, on the power generation unit, the area of the projection of the front electrode may be smaller than the area of the projection of the back electrode, so as to reduce the shading of the front electrode facing the light surface, and facilitate the series connection between the following battery pieces.

The side insulating layer 5 is located between the side conductive member and the side of the power generating unit. The side insulating layer 5 is used for electrically insulating the power generating unit from the side conductive member. The side insulating layer 5 may have one or more layers. Alternatively, the entire dielectric strength of the side insulating layer 5 may be greater than or equal to 3MV/cm, and the entire thickness of the side insulating layer 5 may be greater than or equal to 10 nm. The insulating properties of the side insulating layer 5 are good, only the thickness of the nm level is needed, a good electrical insulating effect can be achieved, in the photovoltaic module, the space occupied by the side insulating layer 5 is small, the area in the photovoltaic module is favorably and fully utilized, the output power of the photovoltaic module can be effectively improved, the insulating properties of the side insulating layer 5 are good, the electrical insulating power generation unit and the side conductive piece can be fully utilized, and the side insulating layer can ensure that the inside of a battery is not short-circuited. In the process of forming the photovoltaic module, the side insulating layer 5 can avoid electrical breakdown and short circuit among the cells, so that the cells can be densely arranged without gaps or with small gaps, the space among the cells is small, the area in the photovoltaic module is fully utilized, and the output power of the photovoltaic module can be effectively improved.

Optionally, the side insulating layer 5 may also wrap all sides of the power generation unit, thereby having a better insulating effect.

As shown in fig. 1 or 2, in the battery cell, a second insulation gap is formed between the first side conductive member 61 and the back electrode 303 to prevent the first side conductive member 61 and the back electrode 303 from being short-circuited. A third insulation gap is provided between the second side conductive member 62 and the front electrode to prevent the second side conductive member 62 from being shorted with the front electrode. The first insulation gap, the second insulation gap, and the third insulation gap may be sized according to actual needs.

Referring to fig. 1, the interconnection strip has conductive segments and insulating segments spaced apart. For example, the front interconnection bar 401 has conductive segments 412 and insulating segments 411 spaced apart. The back interconnection bar 402 has spaced apart conductive segments 413 and insulating segments 414. Fig. 3 shows a schematic top view of a battery string according to an embodiment of the present invention. Fig. 3 may be a schematic view of a cell in a string of cells looking from the light-facing side to the backlight side. Fig. 4 shows a schematic bottom view of a battery string according to an embodiment of the present invention. Fig. 4 may be a schematic view of a backlight surface of a cell in a cell string. Referring to fig. 1, 3 and 4, the first side surface conductive member 61 of one cell is electrically contacted with the second side surface conductive member 62 of the adjacent cell, and thus there is no or little space between the adjacent cells. The conductive segments 412 of the front interconnect strip 401 conductively connect the front electrode of one cell piece to the first side conductive member 61 and the conductive segments 413 of the back interconnect strip 402 conductively connect the back electrode 303 of an adjacent cell piece to the second side conductive member 62 to connect the adjacent cell pieces in series. The insulating segment 411 of the front interconnect strip 401 is opposite the third insulating gap between the front electrode and the second side conductive member 62 and the insulating segment 414 of the back interconnect strip 402 is opposite the second insulating gap between the back electrode 303 and the first side conductive member 61, and no short circuit occurs between cells or inside the cells. The embodiment of the utility model provides an in, the conductive section 412 of the positive interconnection strip 401 of a battery piece, first side conductive piece 61, with the second side conductive piece 62 of adjacent battery piece and the conductive section 413 of back interconnection strip 402, be equivalent to buckle conductive interconnection piece among the prior art, extend to the backlight face of another battery piece from the light facing surface of a battery piece, and then the embodiment of the utility model provides a need not to buckle interconnection strip to the backlight face of battery piece from the light facing surface of battery piece, reduce the stress concentration problem that conductive interconnection piece buckles and lead to, reduce hidden splitting. And an interconnection bar just extends to the other end from the one end of battery cluster, need not the centre and cuts, and the counterpoint is simple, and simple process, production efficiency is high.

As shown in fig. 1, the first side surface conductive member 61 of the left cell is electrically contacted with the second side surface conductive member 62 of the right cell, and further, there is no or very small space between the left and right adjacent 2 cells. Conductive segment 412 of the front interconnect strip 401 conductively connects the front electrode of the left cell piece to the first side conductive member 61 and conductive segment 413 of the back interconnect strip 402 conductively connects the back electrode 303 of the adjacent right cell piece to the second side conductive member 62 to serially connect the 2 left and right adjacent cell pieces.

Optionally, the front electrode of the battery piece is electrically connected with the first side conductive member 61, and the back electrode 303 is also electrically connected with the second side conductive member 62, so that the series connection reliability can be improved.

Fig. 5 shows a schematic partial structure diagram of a battery string according to an embodiment of the present invention. Optionally, referring to fig. 5, a conductive connection layer 801 is disposed between the first side conductive element 61 of one cell and the second side conductive element 62 of an adjacent cell, and the conductive connection layer 801 can increase the conductive reliability between the first side conductive element 61 and the second side conductive element 62, and on the other hand, the adjacent cells can be connected and fixed into a whole through the conductive connection layer 801. And/or, a conductive connecting layer 801 is arranged between the front electrode and the first side conductive piece 61, so that the conductive reliability between the first side conductive piece 61 and the front electrode is improved, and the first side conductive piece 61 and the front electrode are connected and fixed into a whole. Fig. 6 shows a schematic partial structure diagram of another battery string according to an embodiment of the present invention. Optionally, as shown with reference to fig. 6, and/or a conductive connection layer 801 is disposed between the conductive segments 412 of the front interconnection bar 401 and the front electrodes. And/or a conductive connection layer 801 is provided between the conductive segments 412 of the front interconnection bar 401 and the first side conductive members 61. And/or a conductive connection layer 801 is provided between the back electrode 303 and the second side conductive member 62. Fig. 7 is a schematic partial structure diagram of another battery string according to an embodiment of the present invention. And/or, optionally, as shown with reference to fig. 7, a conductive connection layer 801 is disposed between the conductive segments 413 of the back interconnection bar 402 and the back electrode 303. A conductive connection layer 801 is provided between conductive segment 413 of back interconnection bar 402 and second side conductive member 62. The conductive connection layer 801 described above has similar advantageous effects.

Optionally, the conductive connection layer 801 is at least one of a solder conductive connection layer, a conductive adhesive connection layer, and a low-melting-point metal connection layer, and is favorable for conducting connection by heating or other methods, and has good connection and fixation effects.

Optionally, the low melting point metal connecting layer includes the tin layer, can set up the tin layer of one deck low melting point accurately in relevant position through the mode of deposit or electroplating in advance, follow-up only need use modes such as laser or infrared, heat local region for the tin layer melts, conducts electricity, connects, fixes, because the position is convenient for accurate control, and only local heating, can avoid the short circuit problem that electrically conductive connecting layer 801 spills over and leads to.

Fig. 8 shows a schematic structural diagram of another battery string according to an embodiment of the present invention. Fig. 9 shows a schematic top view of another battery string according to an embodiment of the present invention. Fig. 9 may be a schematic view looking from the light-facing side to the backlight side of the cell pieces in the cell string. Fig. 10 is a schematic bottom view of another battery string according to an embodiment of the present invention. Fig. 10 may be a schematic view of a backlight surface of a cell in a cell string. Optionally, as shown in fig. 8, 9, and 10, an electrical isolation member 901 is filled in the second insulation gap, and/or an electrical isolation member 901 is filled in the third insulation gap, where the electrical isolation member 901 plays a good electrical isolation role, so as to avoid an internal short circuit of the battery cell. In the case of providing the conductive connection layer 801, the electrical isolation member 901 can also avoid the problem of short circuit inside the battery cell or the battery string due to flowing, overflowing, or the like of the conductive connection layer 801.

Fig. 11 shows a schematic partial structure diagram of an interconnection bar according to an embodiment of the present invention. Optionally, referring to fig. 11, the interconnection strip includes an insulating base 422 extending in a strip shape, and a conductive body 423 fixed on the insulating base 422, the conductive strip 423 is located at the conductive segment, the surface of the conductive strip 423 near the battery piece is exposed, and the exposed surface of the conductive strip 423 is conductively connected with the front electrode or the back electrode of the battery piece. The strip-like extending direction of the insulating base 422 coincides with the extending direction of the battery string. The dielectric substrate 422 provides good electrical isolation and connects the conductive strips 423 of each conductive segment as a unit.

Optionally, referring to fig. 11, the interconnection bar further includes an insulating bar 421 fixed on the insulating base 422, the insulating bar 421 is located on the insulating segments, and the insulating base 422 plays a good role of electrical insulation and connects the insulating bars 421 of the insulating segments into a whole.

The electrical insulating property of the insulating strip 421 and the insulating base 422 may be substantially the same, or the electrical insulating property of the insulating strip 421 is superior to the electrical insulating property of the insulating base 422, which is not specifically limited in the embodiments of the present invention. The material of the insulating strip 421 and the insulating base 422 may be selected from rubber, plastic, etc.

Optionally, the insulating strip 421 and the insulating base 422 may be integrally formed from the same material, so as to facilitate processing, save the process steps, and improve the production efficiency.

It should be noted that the conductive strips 423 and the insulating strips 421 may be in direct contact, or have an insulating substrate 422 therebetween, but is not limited in particular.

Alternatively, referring to fig. 11, dielectric substrate 422 semi-surrounds conductive strip 423. Fig. 12 shows a partial structure diagram of another interconnection bar according to an embodiment of the present invention. Fig. 13 shows a partial structural schematic diagram of another interconnection bar in the embodiment of the present invention. Alternatively, referring to fig. 12 and 13, dielectric substrate 422 is positioned on one side of conductive strip 423. The insulating substrate 422 and the conductive strips 423 may be disposed in various forms.

Optionally, referring to fig. 12, the interconnection strip includes an insulating base 422 on a side away from the battery piece, a conductive strip 423 on the conductive segment, and an insulating strip 421 on the insulating segment, where the conductive strip 423 and the insulating strip 421 are both located below the insulating base 422, and further, the lower surface of the conductive strip 423 is exposed, and the exposed surface of the conductive strip 423 is conductively connected to the front electrode or the back electrode of the battery piece. The insulating substrate 422 serves as a good electrical insulation and connects the conductive strips 423 and the insulating strips 421 as a whole.

Optionally, referring to fig. 13, the interconnection bar includes an insulating base 422 on a side away from the battery piece, and a conductive bar 423 located in the conductive segment, where the conductive bar 423 is located below the insulating base 422, and a portion of the insulating base 422 not opposite to the conductive bar 423 is used as an insulating segment, so that while a good electrical insulating effect is achieved, material can be saved. In fig. 13, conductive strip 423 is located below the right side of dielectric substrate 422, and no conductive strip 423 is located below the left side of dielectric substrate 422, so that the left side of dielectric substrate 422 serves as a dielectric segment.

Fig. 14 shows a schematic structural diagram of an insulating substrate according to an embodiment of the present invention. Fig. 15 shows a schematic structural view of another insulation base in an embodiment of the present invention. Optionally, referring to fig. 14 and 15, the insulating substrate 422 is clamped to the conductive strip 423. The supporting and fixing function of the insulating base 422 on the conductive strips 423 can be further increased by the clamping function of the insulating base 422. It should be noted that the insulating base 422 may also be clamped to the insulating strip 421, which is not specifically limited in the embodiment of the present invention. In fig. 14, the insulating base 422 is clamped with the conductive strips 423 through the inward-contracting surfaces, and in fig. 15, the insulating base 422 is clamped with the conductive strips 423 through the parts extending inwards from the side close to the battery piece.

Optionally, conductive traces 423 are bonded to dielectric substrate 422 with an adhesive to enhance the bonding strength between dielectric substrate 422 and conductive traces 423. The adhesive is not particularly limited.

Optionally, a welding alloy layer is disposed on the surface of the conductive strip 423 near the battery piece, so as to facilitate conductive connection between the conductive strip 423 and the front electrode or the back electrode. For example, the portion of the conductive strip 423 away from the battery piece may be copper-based alloy, and the surface of the conductive strip 423 near the battery piece is provided with tin-lead alloy.

Alternatively, referring to fig. 1, the front electrode includes a main grid 301, and the conductive segments 412 of the front interconnection bar 401 conductively connect the main grid 301 and the first side conductive member 61 of one cell. And/or the front electrode comprises the fine grid 302, the conductive segment 412 of the front interconnection strip 401 is conductively connected with the fine grid 302 of one cell and the first side conductive piece 61, the conductive connection mode is various, and the conductive connection reliability can be improved. In the case where the main gate 301 is not provided, the first side conductive member 61 may function as a main gate. For the case where there is no fine gate 302, the first side conductive member 61 may function as a fine gate. The first side conductive member 61 prevents poor conduction due to gate breakage.

For example, fig. 16 shows a schematic structural diagram of another battery string according to an embodiment of the present invention. Referring to fig. 16, the front electrode includes a fine grid 302, and the conductive segments 412 of the front interconnection bar 401 conductively connect the fine grid 302 of one cell and the first side conductive member 61, and the first side conductive member 61 may also function as a main grid.

Optionally, the number of the front interconnection bars 401 is less than the number of the front electrodes of one cell, that is, the front interconnection bars 401 are disposed on part of the front electrodes, and the front interconnection bars 401 are not disposed on another part of the front electrodes, so that light shielding can be reduced. And/or, the back interconnection strip 402 is located on the whole backlight surface of the cell, so that the back interconnection strip 402 has a larger contact area with the back electrode of the cell or the cell, which can reduce the resistance and improve the reliability of connection and fixation.

It should be noted that the front interconnection bar 401 and the back interconnection bar 402 may be formed in a shape with a variable width, and particularly, a wide portion to be connected may be formed, so that a thermal influence may be reduced, a connection area may be increased, and connection reliability may be increased. Without the need for the remainder of the connection to be made narrower in width. For example, if the bonding method is used to connect the interconnection bar and the front electrode or the back electrode, the portion of the interconnection bar to be bonded is wider, so that the thermal influence can be reduced, and the bonding area can be increased to prevent cold joint. The front interconnection bar 401 and the back interconnection bar 402 may be identical or different from each other, and are not limited in this embodiment of the invention.

For example, the conductive properties of conductive segment 412 in front interconnection bar 401 may be better than the conductive properties of conductive segment 413 in back interconnection bar 402.

Optionally, the front interconnection bar 401 is a triangular prism or a cylinder, and a cross section of the front interconnection bar 401 perpendicular to an extending direction thereof is a triangle or a circle; and/or, the light-facing surface of the front interconnection bar 401 is provided with a light-reflecting structure, so that heat generation can be reduced, light absorption of the battery piece is increased, and the process is simpler.

Optionally, the cell further includes at least one of a transparent conductive film, a field effect layer, an antireflection film layer, a scattering structure layer, and a light-gathering structure layer on the backlight surface and/or the light-facing surface of the power generation unit, so as to improve the power generation performance of the cell.

Optionally, the conductive strips of the conductive segments in the interconnection strip may be conventional solder strips, and the manufacturing process of the interconnection strip is simple.

Optionally, the insulating layer 5 is silicon oxide (e.g., SiO)_x) Layer, silicon nitride (e.g. SiN)_x) Layer, fluorinated silicon oxide (e.g., SiOF) layer, silicon oxycarbide (e.g., SiOC) layer, aluminum oxide (e.g., Al)₂O₃) Layer, aluminum fluoride (e.g. AlF)_x) A layer of aluminum oxynitride (such as AlON), a layer of magnesium fluoride (such as Mg F)₂) At least one of the layers. The material has good electrical insulation effect, the insulating layer 5 of the material is similar to the preparation process of the passivation layer in the battery piece, the existing production process or equipment of the passivation layer of the battery piece can be directly used, new equipment or process does not need to be added, and the process is simple. It should be noted that x in the chemical formula is a suitable value that can be selected by those skilled in the art according to actual situations.

It should be noted that the insulating layer 5 of the above materials has better insulating performance than organic materials or non-organic materials, such as paraffin, mylar, etc., so that a thinner thickness, such as nm, is required to achieve a better electrical insulating effect. The insulating layer 5 made of the material can be obtained by deposition or growth generally, the thin insulating layer 5 is obtained by deposition or growth, the thickness of the insulating layer 5 is small, namely, in a battery string or a photovoltaic module, the space occupied by the insulating layer 5 is small, the area in the photovoltaic module is more favorably utilized, and the output power of the photovoltaic module can be effectively improved.

Optionally, the insulating layer 5 includes an alumina layer, a silicon nitride layer and a magnesium fluoride layer which are sequentially stacked, wherein the alumina layer is in contact with the power generation unit, namely, in the process of setting the insulating layer 5, the alumina layer is firstly arranged on the side surface of the power generation unit, then the silicon nitride layer is arranged, and then the magnesium fluoride layer is arranged. The thickness of the three layers is not particularly limited, and the total thickness of the three layers may be 10nm or more. For example, the aluminum oxide layer is about 5-40nm thick, the silicon nitride layer is about 10-100nm thick, and the magnesium fluoride layer is about 5-200nm thick, all by deposition.

Optionally, the insulating layer 5 includes a silicon oxide layer, an aluminum oxide layer, and a silicon nitride layer stacked in sequence, where the silicon oxide layer contacts the power generation unit, that is, in the process of setting the insulating layer 5, the silicon oxide layer is firstly set on the side surface of the power generation unit, then the aluminum oxide layer is set, and then the silicon nitride layer is set, the insulating layer 5 has a good electrical insulation effect, and the preparation process uses the existing preparation process of the cell, and the setting sequence of the three layers in the insulating layer 5 also conforms to the setting sequence of the cell, so that the preparation process is simpler, and the preparation efficiency is high. The thickness of the three layers is not particularly limited, and the total thickness of the three layers may be 10nm or more. For example, the silicon oxide layer is about 2nm thick, the aluminum oxide layer is about 35nm thick, and the silicon nitride layer is about 100nm thick. The silicon oxide layer is prepared by adopting an in-situ oxidation process, and the aluminum oxide and the silicon nitride layer are prepared by adopting a deposition method.

Optionally, the insulating layer 5 is disposed between the side surface conductive member and the side surface of the power generation unit in a deposition or growth manner, on one hand, the deposition or growth manner can be achieved by directly using the existing production process or equipment of the battery piece without adding new equipment or process, and the process is simple. On the other hand, the thickness of the insulating layer 5 formed in a deposition or growth mode is thin and convenient to control, and can generally reach the nm level, and in the photovoltaic module, the space occupied by the insulating layer 5 is small, so that the area in the photovoltaic module can be more favorably fully utilized, and the output power of the photovoltaic module can be effectively improved.

The front electrode and the side conductive piece can be arranged in a printing mode, and the utility model discloses in, do not do specifically and restrict. The side conductive piece can also be manufactured in a coating and drying mode. For example, silver paste is coated on the surface of the insulating layer 5, and then dried to obtain the side conductive member. The material of the side conductive piece can be the same as that of the front electrode, so that the side conductive piece and the front electrode can be manufactured at one time.

The utility model discloses embodiment mode still provides a photovoltaic module, and this photovoltaic module includes: the aforesaid at least 1 battery cluster. The photovoltaic module can refer to the description of the battery string, and has the same or similar beneficial effects as the battery string, and the details are not repeated herein to avoid repetition.

The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and scope of the present invention, and all of them fall within the protection scope of the present invention.

Claims

1. A battery string is characterized by comprising a plurality of battery pieces and interconnection bars extending from one end to the other end of the battery string; the interconnection strips comprise front interconnection strips positioned on the light-facing surfaces of the plurality of battery pieces and back interconnection strips positioned on the back light surfaces of the plurality of battery pieces;

the battery piece includes: the power generation device comprises a power generation unit, a front electrode, a back electrode, a side insulating layer and a side conductive piece; the power generation unit is provided with a light facing surface, a backlight surface and a side surface, wherein the light facing surface and the backlight surface are oppositely arranged, and the side surface is connected with the light facing surface and the backlight surface; the front electrode is positioned on the light facing surface of the power generation unit; the back electrode is positioned on a backlight surface of the power generation unit; the side surface insulating layer is positioned between the side surface conductive piece and the side surface of the power generation unit; the side surface conductive pieces comprise a first side surface conductive piece and a second side surface conductive piece which are positioned on different sides of the power generation unit; a first insulation gap is formed between the first side surface conductive piece and the second side surface conductive piece; a second insulation gap is formed between the first side surface conductive piece and the back electrode; a third insulation gap is formed between the second side surface conductive piece and the front electrode;

the interconnection bar is provided with conductive segments and insulating segments which are distributed at intervals; the first side surface conductive piece of one battery piece is electrically contacted with the second side surface conductive piece of the adjacent battery piece, the conductive section of the front interconnection strip is electrically connected with the front electrode of one battery piece and the first side surface conductive piece, and the conductive section of the back interconnection strip is electrically connected with the back electrode of the adjacent battery piece and the second side surface conductive piece so as to connect the adjacent battery pieces in series; the insulating section of the front interconnection bar is opposite to the third insulating gap, and the insulating section of the back interconnection bar is opposite to the second insulating gap.

2. The battery string of claim 1, wherein a conductive connection layer is disposed between the first side conductive member of one cell and the second side conductive member of an adjacent cell;

3. The battery string according to claim 1 or 2, wherein the second insulating gap is filled with an electrical separator, and/or the third insulating gap is filled with an electrical separator.

4. The battery string according to claim 2, wherein the conductive connection layer is at least one of a solder conductive connection layer, a conductive adhesive connection layer, and a low melting point metal connection layer.

5. The battery string according to claim 4, wherein the low-melting-point metal connection layer comprises a tin layer.

6. The battery string according to claim 1, wherein the interconnection bar comprises a strip-shaped extending insulating base, a conductive bar fixed on the insulating base; the conductive strip is positioned on the conductive segment;

the conductive strips are exposed close to the surface of the battery piece.

7. The battery string according to claim 6, wherein the insulating matrix semi-surrounds the conductive strip; or, the insulating matrix is positioned on one side of the conductive strip.

8. The battery string according to claim 6, wherein the interconnection bar further comprises an insulating bar fixed to the insulating base; the insulating strip is located in the insulating section.

9. The battery string as claimed in claim 6, wherein the conductive strip is clamped to the insulating base or bonded to the insulating base.

10. The battery string according to claim 8, wherein the insulating strip and the insulating base are integrally formed.

11. The battery string according to any one of claims 6 to 9, wherein the surface of the conductive bar adjacent to the battery piece is provided with a welding alloy layer.

12. The battery string according to claim 1 or 2, wherein the cross-section of the front interconnection bars is triangular or circular; and/or a light-facing surface of the front interconnection strip is provided with a light-reflecting structure.

13. The battery string according to claim 1 or 2, wherein the power generation unit includes a PN junction.

14. The battery string according to any one of claims 6 to 9, wherein the conductive strips are solder strips.

15. A photovoltaic module, comprising: the battery string according to any one of claim 1 to claim 14.