Battery piece and battery assembly

Abstract

The utility model discloses a battery piece and a battery assembly, the battery assembly comprises a battery piece and a copper interconnection strip, the battery piece is provided with a metal grid line and a copper metal connection part connected with the metal grid line; and the interconnection strips are stacked on the copper metal connecting parts in an aligned manner and are connected with the copper metal connecting parts. Therefore, the copper interconnection strip and the copper metal connection part form a copper-copper butt-joint interconnection structure, so that the situation of poor connection between the copper interconnection strip and the copper metal connection part is avoided, and the conversion efficiency of the battery assembly is ensured; before the assembly is laminated, the battery pieces and the interconnection strips are pre-connected, the overall thickness of the pre-connected battery pieces and the interconnection strips is large, and the interconnection strips pre-connected with the battery pieces can disperse stress generated by stacking of the battery pieces, so that hidden cracks of the battery pieces in the conveying process can be reduced, and the manufacturing cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic product preparation technical field especially relates to a cell piece and battery assembly. BACKGROUND

[0002] The conventional solar cell assembly includes cell piece, interconnecting strip, backboard, film for encapsulation, glass and other components, the metal grid line is formed on the cell piece by printing silver paste or electroplating, and then the soldering tin points are coated on the metal grid line at intervals. When manufacturing the battery assembly, first, the components are prepared, then the components are transported to a place, the interconnecting strip is placed on the soldering tin points, and then the backboard, film for encapsulation, glass and other components are combined with the cell piece and interconnecting strip according to the preset position, and finally, the whole is laminated to obtain the final battery assembly.

[0003] In the above manner, the interconnecting strip is connected with the cell piece by soldering, but this method can hardly avoid the occurrence of the conditions of missing welding, false welding and empty welding, which can lead to poor connection between the cell piece and the metal grid line, and thus low conversion efficiency of the battery assembly. Moreover, the contact between the interconnecting strip and the silver grid line through the soldering layer has a relatively high resistance, so the conversion efficiency of the battery assembly is not very ideal. The adhesion of the silver grid line is not very high, so the silver grid line is made very wide for connection performance. Because the cost of silver paste is relatively high, the setting of the wide silver grid line can increase the cost, and the wider the silver grid line is, the more the cell piece is covered, and the less the current collected, so the conversion efficiency of the battery assembly is worse. UTILITY MODEL CONTENTS

[0004] The utility model aims at overcoming the above-mentioned defects, and provides a cell piece and battery assembly, the copper metal connecting portion connected with the metal grid line is arranged on the cell piece, the copper interconnecting strip is placed and connected on the copper metal connecting portion, and the copper-copper butt joint interconnection structure is formed, so that the poor connection between the cell piece and the copper interconnecting strip is avoided, and the conversion efficiency of the battery assembly is ensured.

[0005] To achieve the above-mentioned purpose, the utility model adopts the technical scheme of:

[0006] A cell piece, the metal grid line is arranged on the cell piece, the copper metal connecting portion is further arranged on the cell piece, and the copper metal connecting portion is connected with the metal grid line.

[0007] At least one of the metal grid lines extending along the length direction of the cell sheet is provided as the copper metal connecting part, and the width of the metal grid line provided as the copper metal connecting part is greater than that of the other metal grid lines; or, at least one position of at least one of the metal grid lines extending along the length direction of the cell sheet has a width greater than that of other positions of the metal grid line, and the position of the metal grid line where the width is greater forms a copper metal connecting part; or, a plurality of copper metal connecting parts are provided at intervals, and the plurality of copper metal connecting parts are distributed in a grid shape, and the plurality of copper metal connecting parts located on the same straight line are connected by the metal grid lines in the direction of the straight line, and the width of the copper metal connecting part is greater than that of the metal grid line.

[0008] When one or more copper metal connecting parts are provided, each of the positions where the copper metal connecting parts are located is the intersection of the metal grid line extending along the horizontal direction of the cell sheet and the metal grid line extending along the width direction of the cell sheet.

[0009] The height of the copper metal connecting part is equal to that of the metal grid line; preferably, the outer surface of the copper metal connecting part is provided with an anti-oxidation protective agent layer.

[0010] Preferably, the metal grid line is provided as a copper metal grid line or at least the uppermost layer of the metal grid line is provided as a copper plating layer.

[0011] A battery assembly includes a copper interconnection strip and the above-mentioned cell sheet, and the copper interconnection strip is positioned and stacked on the copper metal connecting part and connected with the copper metal connecting part.

[0012] The upper surface of the copper metal connecting part is provided with two spaced-apart thermosetting adhesives, the copper interconnection strip is positioned and stacked between the two spaced-apart thermosetting adhesives, and the copper metal connecting part and the copper interconnection strip are connected through the thermosetting adhesives; preferably, the thickness of the thermosetting adhesive is not more than the height of the copper interconnection strip; preferably, the thickness of the thermosetting adhesive is set to 5-50 um.

[0013] The upper side of the copper metal connecting part and the positions on both sides of the copper interconnection strip are provided with a flux, and the flux contacts both sides of the copper interconnection strip, and the copper metal connecting part and the copper interconnection strip are welded together through the flux; preferably, the thickness of the flux is not more than the height of the copper interconnection strip.

[0014] The part of the copper interconnection strip connected with the copper metal connecting part is covered with a glue melting strip, and the copper interconnection strip is connected with the copper metal connecting part through the glue melting strip; preferably, the glue melting strip includes a body and attachment parts extending outward from both sides of the body, the body covers the upper side of the copper interconnection strip, and the ends of the attachment parts away from the body contact the surface of the cell sheet along the sides of the copper interconnection strip and the sides of the copper metal connecting part.

[0015] Because this utility model adopts the above-mentioned technical solution, it has the following beneficial effects:

[0016] 1. The battery cell of this utility model is provided with a copper metal connection part that connects to the metal grid lines. Furthermore, the copper interconnect strips are directly stacked on the copper metal connection part, so that after the copper interconnect strips and the copper metal connection part are connected and fixed, the copper metal connection part and the copper interconnect strips on the battery cell form a direct copper-copper interconnect structure. Compared with the conventional method of connecting the battery cell and the interconnect strips by soldering, this direct copper-copper interconnect structure of this utility model avoids poor contact, thus ensuring the conversion efficiency of the battery module. Compared with the connection between the interconnect strips and the conventional method of printing silver paste to form metal grid lines, this direct copper-copper interconnect structure of this utility model has lower contact resistance, thereby further improving the current collection and current collection efficiency, and thus further improving the conversion efficiency of the battery module.

[0017] 2. Before laminating the modules, the cells and interconnects are pre-connected. Then, the pre-connected cells, interconnects, and other components of the battery module are laminated. Compared to individual cells, the pre-connected cells and interconnects are thicker overall. The interconnects pre-connected to the cells can also distribute the stress generated by stacking the cells. Thus, during transportation, the cells are no longer transported individually, but rather as a whole. This reduces the occurrence of microcracks in the cells during transportation, thereby reducing damage to the cells and lowering the overall manufacturing cost of the battery module. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the first embodiment of the battery cell of this utility model;

[0019] Figure 2 This is a schematic diagram of the second embodiment of the battery cell of this utility model;

[0020] Figure 3 This is a schematic diagram showing the interconnecting strips stacked in a triangular shape on the copper metal connection part of the battery cell.

[0021] Figure 4 This is a schematic diagram of the third embodiment of the battery cell of this utility model;

[0022] Figure 5 This is a schematic diagram of the fourth embodiment of the battery cell of this utility model;

[0023] Figure 6 This is a schematic diagram of the fifth embodiment of the battery cell of this utility model;

[0024] Figure 7The utility model discloses a schematic diagram of interconnecting strip, copper metal connecting part, battery piece and hot melt glue combination after combination;

[0025] Figure 8 The utility model discloses a schematic diagram of interconnecting strip, copper metal connecting part, battery piece and hot melt glue combination after combination;

[0026] Figure 9 It is according to Figure 8 The enlarged schematic diagram of part A.

[0027] Figure 10 The utility model discloses a schematic diagram of hot melt strip of glue of the utility model is covered in interconnecting strip, copper metal interconnecting strip, metal grid line outside;

[0028] Figure 11 The utility model discloses an enlarged plane schematic diagram of hot melt strip of glue. Specific implementation

[0029] As Figures 1 to 6 The utility model discloses a battery piece 1, be provided with metal grid line 3 on the battery piece, still be provided with the copper metal connecting part 4 that supplies interconnecting strip 2 connection on the battery piece 1, copper metal connecting part 4 is connected with metal grid line 3.

[0030] It can be printed silver paste on the battery piece 1 and form the metal grid line 3, namely the metal grid line 3 is provided as silver grid line, in this embodiment, preferably, the metal grid line 3 is provided as copper metal grid line or the metal grid line is at least the uppermost layer copper plating layer, and the metal grid line 3 is formed by electroplating.

[0031] The utility model discloses a battery assembly, the battery assembly includes copper interconnecting strip 2 and above-mentioned battery piece 1, copper interconnecting strip 2 is located on copper metal connecting part 4 and is connected with copper metal connecting part 4 by alignment.

[0032] The metal grid line 3 is at least the outermost layer copper plating layer, namely if the metal grid line 3 is multilayer layered electroplating, at least the outermost layer is copper plating layer, preferably, the metal grid line 3 is copper metal grid line 3 as a whole, namely no matter is layered electroplating or integral type electroplating, all is copper plating layer, and the connection effect is better like this.

[0033] The metal grid line 3 includes the grid line 3 along the length direction of silicon piece and the grid line 3 along the width direction of silicon piece, and the grid line 3 in different directions is connected into a grid shape. The metal grid line 3 is synchronously electroplated with the copper metal connecting part 4, so that the manufacturing efficiency is higher.

[0034] In the first embodiment, at least one of the metal grid lines 3 extending along the length direction of the cell sheet 1 is set as the copper metal connecting part 4, and the width of the metal grid line 3 set as the metal connecting part is greater than that of the other metal grid lines 3. During electroplating, the other metal grid lines 3 on the cell are electroplated simultaneously with the metal grid line 3 set as the copper metal connecting part 4, except that the electroplating width of the metal grid line 3 set as the copper metal connecting part 4 is greater than that of the other metal grid lines 3. The overlapping connection position of the interconnecting strip 2 and the cell sheet 1 can be the same as the connection position of the interconnecting strip 2 and the cell sheet 1 in a conventional cell module.

[0035] In the first embodiment, at least one of the metal grid lines 3 extending along the length direction of the cell sheet 1 is set as the copper metal connecting part 4, and the width of the metal grid line 3 set as the metal connecting part is greater than that of the other metal grid lines 3. During electroplating, the other metal grid lines 3 on the cell are electroplated simultaneously with the metal grid line 3 set as the copper metal connecting part 4, except that the electroplating width of the metal grid line 3 set as the copper metal connecting part 4 is greater than that of the other metal grid lines 3. The overlapping connection position of the interconnecting strip 2 and the cell sheet 1 can be the same as the connection position of the interconnecting strip 2 and the cell sheet 1 in a conventional cell module. Figure 1 The metal grid line 3 set as the copper metal connecting part 4 is the outermost metal grid line 3 on one side (as shown in the figure), and the one side of each interconnecting strip 2 is overlapped on the metal grid line 3 at a predetermined position interval during alignment and overlapping. Specifically, the position of the one side of the interconnecting strip 2 overlapped on the copper metal connecting part 4 is the intersection position of the metal grid line 3 and the metal grid line 3 extending along the width direction of the cell sheet 1. In other specific embodiments, the metal grid line 3 set as the copper metal connecting part 4 can not be the outermost metal grid line 3, but one or more metal grid lines 3 between the two outermost metal grid lines 3.

[0036] In the second embodiment, at least one of the metal grid lines 3 extending along the length direction of the cell sheet 1 has a width greater than that of other positions of the metal grid line 3, and the position of the metal grid line 3 with a greater width forms a copper metal connecting part 4.

[0037] At least one of the metal grid lines 3 forms a copper metal connecting part 4, that is, only one metal grid line 3 can form a copper metal connecting part 4, or one metal grid line 3 can form multiple copper metal connecting parts 4, or multiple metal grid lines 3 can form one or more copper metal connecting parts 4. Before electroplating the metal grid lines 3, the distribution of each metal grid line 3 and the position distribution of each copper metal connecting part 4 on the predetermined metal grid line 3 are planned; during electroplating, the position distribution of each copper metal connecting part 4 is electroplated with a wider copper plating layer to form the copper metal connecting part 4, and other electroplated positions are electroplated with a finer copper plating layer to form the metal grid line 3. That is, during electroplating of the metal grid lines 3 extending along the length direction of the cell sheet 1, at least one predetermined position of at least one of the metal grid lines 3 has an electroplating width greater than that of other positions of the metal grid line 3, and the position of the metal grid line 3 with a greater electroplating width forms the copper metal connecting part 4.

[0038] In the second embodiment, among the metal grid lines 3 extending along the length direction of the battery sheet 1, the outermost metal grid line 3 is provided with a plurality of copper metal connecting parts 4 (as shown in Figure 2 ). That is, the copper metal connecting parts 4 are provided at intervals, and the plurality of copper metal connecting parts 4 are provided on one side of the battery sheet 1 and located on the same straight line, and the plurality of copper metal connecting parts 4 are connected by the metal grid line 3 in the direction of the straight line. One side of the plurality of interconnection strips 2 is respectively overlapped on the corresponding copper metal connecting part 4 (as shown in Figure 3 ). Preferably, each copper metal connecting part 4 is connected with one end of the metal grid line 3 extending along the width direction of the battery sheet 1. In other embodiments, the non-outermost metal grid line 3 can also be provided with a plurality of copper metal connecting parts 4 at intervals.

[0039] When a plurality of copper metal connecting parts 4 are formed on one metal grid line 3, the interval distance between adjacent copper metal connecting parts can be set to be different, as shown in Figure 2 . The connection position of the outermost metal grid line 3 and each metal grid line 3 extending along the width direction of the battery sheet 1 is provided with a copper metal connecting part 4. In the third embodiment, as shown in Figure 4 , only the connection position of the metal grid line 3 extending along the width direction of the battery sheet 1 and the outermost metal grid line 3 is provided with the copper metal connecting part 4. In other embodiments, the interval position of the copper metal connecting part 4 can also be adjusted as needed, and the number of copper metal connecting parts 4 can also be adjusted as needed.

[0040] In the fourth embodiment, as shown in Figure 5 , the copper metal connecting parts 4 are provided at intervals, and the plurality of copper metal connecting parts 4 are distributed in a grid shape, and the plurality of copper metal connecting parts 4 located on the same straight line are connected by the metal grid line 3 in the direction of the straight line, and the width of the copper metal connecting part is greater than the width of the metal grid line. Specifically, among the plurality of copper metal connecting parts 4 in each row and each column of the plurality of rows of copper metal connecting parts extending along the length direction of the battery sheet 1 and the plurality of rows of copper metal connecting parts extending along the width direction of the battery sheet 1, each row and each column of the plurality of copper metal connecting parts 4 are connected by the metal grid line 3 in the corresponding straight line direction. That is, a plurality of copper metal connecting parts are formed on the plurality of rows and columns of metal grid lines. Under this design, one interconnection strip 2 is overlapped on one column of the plurality of copper metal connecting parts 4.

[0041] When the plurality of copper metal connecting parts 4 are distributed in a grid shape, the density of the grid formed by the plurality of copper metal connecting parts 4 is also different, that is, the interval distance of each row and each column of the plurality of copper metal connecting parts 4 in different grids can also be set to be different. In the fifth embodiment, as shown in Figure 6 , the interval distance of each row and each column of the plurality of copper metal connecting parts 4 is greater than that of the fourth embodiment as shown in Figure 5 .

[0042] The copper metal connecting part 4 can be arranged in a circular, rectangular, oblate, triangular or other shape (as shown in Figures 7 to 10 different shapes in different embodiments).

[0043] In the above embodiments, the height of the copper metal connecting part 4 is equal to the height of the metal grid line 3, so as to avoid the connection of the interconnecting strip 2 and the copper metal connecting part from being leaked, thereby avoiding poor connection.

[0044] In the above embodiments, when one or more copper metal connecting parts 4 are arranged, preferably, each of the copper metal connecting parts 4 is located at the intersection of the metal grid line 3 extending along the horizontal direction of the battery piece 1 and the metal grid line 3 extending along the width direction of the battery piece 1. In this way, the current collected and transmitted by the metal grid line 3 can be better conducted through the copper metal connecting parts 4 and the interconnecting strip 2.

[0045] The method for electroplating the electroplated metal grid line and the copper metal connecting part on the battery piece can adopt any known and feasible technology, and since it is not the focus of the present application, it will not be described here.

[0046] The interconnecting strip 2 is arranged as a copper interconnecting strip 2, that is, the interconnecting strip 2 can be a pure copper or a copper alloy interconnecting strip 2. The copper alloy can be brass (Cu-Zn alloy), bronze (Cu and Sn, Al, Si, etc. alloy), white copper (Cu-Ni), copper lead (Cu-Pb) or copper bismuth (Cu-Bi) and the like.

[0047] Corresponding to the shape of the copper metal interconnecting strip, the cross-sectional shape of the interconnecting strip 2 can be a conventional shape, that is, a circular shape, or a rectangular, oblate, triangular or other shape. That is, the shape of the metal connecting part 4 and the interconnecting strip 2 is not limited, as long as the above connection can be achieved.

[0048] In one embodiment, as shown in Figure 7 the upper surface of the copper metal connecting part 4 is provided with two spaced heat curing glue 5, the copper interconnecting strip 2 is aligned and overlapped between the two spaced heat curing glue 5, and the copper metal connecting part 4 and the copper interconnecting strip 2 are connected by the heat curing glue 5.

[0049] The thickness of the heat curing glue 5 is not more than the height of the copper interconnecting strip 2, and preferably, the thickness of the heat curing glue 5 is lower than the height of the copper interconnecting strip 2.

[0050] When the copper metal connecting part is provided as one or more, two thermosetting adhesives are prepared on the upper surface of each copper metal connecting part. When the copper metal connecting part 4 is provided as a straight line, i.e. one of the metal grid lines 3 is provided as the copper metal connecting part 4, one or more groups of thermosetting adhesives are provided on the straight line copper metal connecting part 4 (i.e. the metal grid line), each group of thermosetting adhesives including the two spaced thermosetting adhesives, i.e. each group of thermosetting adhesives corresponds to one interconnecting strip.

[0051] Preferably, when the copper metal connecting part is provided as one or more, the outer sides of the thermosetting adhesives on the two sides of the upper surface of the copper metal connecting part are respectively aligned with the two sides of the upper surface of the copper metal connecting part.

[0052] In another embodiment, as shown in Figure 8 、 9 The upper side of the copper metal connecting part 3 and the position on the two sides of the copper interconnecting strip 4 are provided with a flux 6, and the flux 6 is in contact with the two sides of the copper interconnecting strip 4, and the copper metal connecting part 3 and the copper interconnecting strip 4 are welded together through the flux 6.

[0053] When the copper metal connecting part is provided as one or more, the flux 6 is prepared on the upper surface of each copper metal connecting part and on the two sides of the interconnecting strip. When the copper metal connecting part 3 is provided as a straight line, i.e. one of the metal grid lines 2 is provided as the copper metal connecting part 3, the flux 6 is prepared on the two sides of each interconnecting strip on the straight line copper metal connecting part 3 (i.e. the metal grid line).

[0054] The thickness of the flux 6 does not exceed the height of the copper interconnecting strip 4, and preferably the thickness of the flux 6 is lower than the height of the copper interconnecting strip 4. In this way, after the interconnecting strip 4 and the copper metal connecting part are connected, the flux 6 does not exceed the height of the copper interconnecting strip 4 and affects the assembly of other parts of the battery assembly.

[0055] The flux 6 is a conventional flux 6, and the preparation method of the flux 6 is also a conventional method. When the flux 6 is heated, any known and feasible method can be used, and it is not the utility model point of the utility model, so it is not described here.

[0056] The utility model also discloses a manufacturing method of a battery assembly, and the manufacturing method comprises:

[0057] S1, the metal grid line 3 and the copper metal connecting part 4 connected are provided on the battery sheet 1.

[0058] S2, the copper interconnecting strip is aligned and stacked on the copper metal connecting part and the copper interconnecting strip and the copper metal connecting part are connected.

[0059] S3, laminating the connected battery piece 1, the interconnection strip 2 and other components of the battery assembly to obtain the battery assembly.

[0060] Further, when the copper metal connecting part 4 upper surface is provided with two spaced heat curing glue 5, the S2 includes:

[0061] S21, preparing two spaced heat curing glue 5 on the upper surface of the copper metal connecting part 4;

[0062] S22, aligning and stacking the copper interconnection strip 2 between the two spaced heat curing glue 5 on the upper surface of the copper metal connecting part 4;

[0063] S23, heating the heat curing glue 5, and connecting the copper metal connecting part 4 and the copper interconnection strip 2 after the heat curing glue 5 is heated and melted. Thus, the pre-connected fixed interconnection strip and battery piece are obtained, and the interconnection strip and battery piece are copper-copper butt joint interconnection structure.

[0064] When the heat curing glue is prepared on the copper metal interconnection strip, any known and feasible way such as printing, spraying, dropping, and attaching can be used to prepare the heat curing glue on the copper metal connecting part.

[0065] In the embodiment, when the heat curing glue is prepared, the thickness of the heat curing glue is set to 5-50um. Preferably, the thickness of the heat curing glue is set to 10, 15, 20, 25, 30, 32, 35, 38, 40, 45 or 48mm. The thickness of the heat curing glue is set in this way, and a clear accommodating space can be formed between the two spaced heat curing glue on the same copper metal connecting part for aligning and stacking the interconnection strip, so that the alignment operation of the interconnection strip and the copper metal connecting part is easier. Moreover, the heat curing glue of this thickness is not too much, but can stably connect the interconnection strip and the copper metal connecting part after being heated and melted. Moreover, because the heat curing glue is on the copper metal connecting part and located on both sides of the interconnection strip, when the heat curing glue is heated, the heat curing glue is basically connected to both sides of the interconnection strip and both sides of the copper metal connecting part, and basically does not penetrate into the butt joint surface of the copper interconnection strip and the copper metal connecting part, so that the copper-copper butt joint of the copper metal connecting part and the copper interconnection strip can be better guaranteed. Moreover, the heat curing glue will be melted and coated on the copper interconnection strip 2 connected with the copper metal connecting part 4 of the battery piece after being heated, so that the oxidation of the copper metal can be avoided, thereby further improving the conductivity between the interconnection structure, and further guaranteeing the output power of the final battery assembly.

[0066] The heating temperature of the thermosetting glue is set to 60-200℃, and the heating time is 0.5-3 seconds. Preferably, the heating temperature is set to 80, 100, 120, 150, 160, 180 or 190℃, and the heating time is 0.8, 1, 1.2, 1.5, 1.8, 2, 2.3, 2.5, 2.6 or 2.8 seconds. The heating temperature and heating time are set to make the thermosetting glue of the above thickness melt well to connect the copper interconnection strip and the copper metal connecting part 4, and the thermosetting glue cannot completely become a liquid state to flow into the abutting surface of the copper interconnection strip and the copper metal connecting part, nor flow too much to cause the interconnection strip to be unable to be connected.

[0067] When the thermosetting glue 5 is heated, a lamp heating source, a laser heating source or an infrared light heating source can be used for heating. The specific operation is not described here.

[0068] When the upper surface of the copper metal connecting part 4 is provided with the flux 6, the S2 comprises:

[0069] S21, the copper interconnection strip 4 is aligned and overlaid on the copper metal connecting part 3;

[0070] S22, the flux 6 is prepared on the upper side of the copper metal connecting part 3 and at the positions on both sides of the copper interconnection strip 4, and the flux 6 is in contact with both sides of the copper interconnection strip 4;

[0071] S23, the flux 6 is heated to melt the flux 6 to weld the copper metal connecting part 3 and the copper interconnection strip 4 together; in this way, the interconnection strip and the battery piece are obtained, and the copper metal connecting part on the interconnection strip and the battery piece is a copper-copper direct abutting interconnection structure.

[0072] When the flux 6 is heated, the heating temperature is set to 120-200℃, and the heating time is 0.5-3 seconds. Preferably, the heating temperature is set to 130, 150, 160, 180 or 190℃, and the heating time is 0.8, 1, 1.2, 1.5, 1.8, 2, 2.3, 2.5, 2.6 or 2.8 seconds. The heating temperature and heating time are set to make the above flux 6 melt well to connect the copper interconnection strip and the copper metal connecting part 3, which takes into account the heating effect and heating time, and achieves a good balance in efficiency and effect.

[0073] Preferably, before the interconnection strip is aligned and overlaid on the copper metal connecting part, the copper metal connecting part 4 is covered with an anti-oxidation protective agent layer, which can well protect the copper metal connecting part from rusting, oxidizing and sulfidation, thereby being more conducive to the subsequent connection of the interconnection strip and the copper metal connecting part, and ensuring the current flow efficiency after the battery piece and the interconnection strip are connected. The method of coating an anti-oxidation protective agent layer can be any known and feasible technical solution.

[0074] The thermosetting adhesive 5 and flux 6 are prepared on the antioxidant protective layer of the copper metal connection.

[0075] Furthermore, before aligning and stacking the interconnect strip 2 onto the copper metal connector, an antioxidant layer is also applied to the interconnect strip. This provides the interconnect strip with excellent protection against oxidation and moisture, further ensuring its connection function with the copper metal connector and thus further guaranteeing the efficiency of the battery assembly.

[0076] The antioxidant can be OSP, and the antioxidant layer is an OSP film with a thickness of 0.001-0.005 mm. Therefore, when the thermosetting adhesive and flux 6 are heated, the antioxidant at the corresponding positions of the copper metal connector 4 and the copper interconnect strip 2 will melt due to heat and will no longer cover the outside of the copper metal connector 4 and the copper interconnect strip 2. Thus, the coating of the antioxidant will not affect the direct copper-to-copper connection between the copper metal connector 4 and the copper interconnect strip 2. In other words, the antioxidant can protect the copper metal connector and the copper interconnect strip from oxidation without affecting the direct copper-to-copper connection between the copper metal connector 3 and the copper interconnect strip 4.

[0077] In another embodiment, such as Figure 10 , 11 As shown, the copper interconnect strip 2 is covered with a fusion strip 7 at least on the part that is connected to the copper metal connection part 4. The copper interconnect strip 2 is connected to the copper metal connection part 4 through the fusion strip 7, that is, the fusion strip 7 is heated and melted to connect and fix the copper metal connection part to the copper interconnect strip 2.

[0078] In this further embodiment, the adhesive bonding strip 7 includes a body 71 and attachment portions 72 extending outward from both sides of the body 71. The body 71 covers the upper side of the interconnecting strip 2, and the ends of the attachment portions 72 away from the body 71 extend downward along both sides of the interconnecting strip 2 and the copper metal connection portion 4, respectively, and contact the surface of the battery cell 1. This arrangement ensures that the interconnecting strip 2, the copper metal connection portion 4, and the battery cell 1 are connected and fixed together by the adhesive bonding strip 7.

[0079] The body 71 and the attachment portion 72 can be a single rectangular unit. In this embodiment, multiple attachment portions 72 extend from each side of the body 71 at intervals. The shape of the attachment portion 72 can be set to various feasible regular or irregular shapes such as rectangles, triangles, and T-shapes. The multiple attachment portions 72 are spaced apart, which can reduce the amount of adhesive used while achieving the connection and fixation function, thereby saving costs.

[0080] The width of the body 71 is not less than the width of the interconnecting strip 2, preferably, the width of the body 71 is greater than the width of the interconnecting strip 2. In this way, it can be ensured that the position on the upper side of the interconnecting strip 2 originally covered by the glue melting strip 7 is covered by the glue after the glue melting strip 7 is melted, so that the effect of preventing oxidation of the copper metal is good.

[0081] The glue melting strip 7 can be only laid on the position where the interconnecting strip 2 is connected with the copper metal connecting part 4, in this way, the glue melting strip 7 covers the upper side of the part of the interconnecting strip 2 connected with the copper metal connecting part 4, and the other part of the interconnecting strip 2 not covered by the copper metal interconnecting strip 2 is not covered by the glue melting strip 7. In other embodiments, the entire interconnecting strip 2 can be laid with a glue melting strip 7 extending along the length direction of the interconnecting strip 2, and the adhesive parts 72 on both sides of the glue melting strip 7 respectively contact the surface of the battery piece 1 below the interconnecting strip 2. In this way, the connection between the interconnecting strip 2 and the battery piece 1 can be more stable, and the upper side of the interconnecting strip 2 is entirely covered by the glue, so that the effect of preventing oxidation of the copper metal is better.

[0082] In the embodiment, the thickness of the glue melting strip 7 is set to 0.05-0.08mm. Preferably, the thickness of the glue melting strip 7 is set to 0.06 or 0.07mm. The thickness of the glue melting strip 7 is set in this way, so that the heating thereof does not need too long time, but after melting, it can be quickly solidified without heating, so that the interconnecting strip 2 and the copper metal connecting part 4 and the silicon piece are quickly connected together. In this way, the purpose of quick connection can be achieved, and the cost of the glue melting strip 7 can be controlled to the maximum extent.

[0083] When the copper interconnecting strip 2 is covered with the glue melting strip 7, the S2 comprises:

[0084] S21, the copper interconnecting strip 2 is laid on the copper metal connecting part in position;

[0085] S22, the glue melting strip 7 is placed on the copper interconnecting strip 2, and the part of the copper interconnecting strip 2 connected with the copper metal connecting part 4 is covered with the glue melting strip 7;

[0086] S23, the glue melting strip 7 is heated, and after the glue melting strip 7 is melted and adhered, the copper metal connecting part and the copper interconnecting strip 2 are connected and fixed. In this way, the pre-connected and fixed interconnecting strip 2 and the battery piece 1 are obtained, and the interconnecting strip 2 and the battery piece 1 are a copper-copper butt joint interconnecting structure.

[0087] When the glue melting strip 7 is heated, the heating temperature is set to 60-200 DEG C, and the heating time is 0.5-3 seconds. Preferably, the heating temperature is set to 80, 100, 120, 150, 160, 180 or 190 DEG C, and the heating time is 0.8, 1, 1.2, 1.5, 1.8, 2, 2.3, 2.5, 2.6 or 2.8 seconds. The heating temperature and the heating time are set to make the glue melting strip 7 of the above thickness melt well to connect the copper interconnection sleeve and the copper metal connecting part 4 with the battery piece 1.

[0088] When the glue melting strip 7 is heated, a lamp heating source, a laser heating source or an infrared light heating source can be used to heat. The assembly laminating method is a conventional technology, for example, the assembly laminating operation condition is that the curing time is 20 minutes, the curing temperature is 220 DEG C, and the pressure is 0.7 MPa, which will not be repeated here.

[0089] The thermosetting glue and the glue melting strip can be POE (Polyolefin elastomer, also known as polyethylene oxide or polyoxyethylene), EVA glue material or co-extrusion glue material. When the assembly is laminated later, it can be combined with other packaging materials without removing. In this way, unnecessary subsequent processes can be reduced, and unnecessary working hours can be saved.

[0090] The other components of the battery assembly include but are not limited to packaging mold material, back plate, glass and the like. The other components of the battery assembly are conventional components, so they will not be listed one by one. The other components and the battery piece 1 and the interconnection strip 2 are laminated to obtain the battery assembly. When the assembly is laminated, the packaging mold material, the back plate, the glass and the like are placed and arranged according to the predetermined structure of the battery assembly, and then laminated. When laminated, the curing time is 15-25 minutes, the curing temperature is 200-250 DEG C, and the laminating pressure is 0.4-1.2 MPa. For example, the curing time is 18, 20, 22 or 24 minutes, the curing temperature is 210, 220, 230 or 240 DEG C, and the laminating pressure is 0.5, 0.7, 0.8, 1 or 1.1 MPa. The assembly laminating method can use known technology, and is not the focus of the present application, so it will not be repeated here.

[0091] As described above, the copper metal connecting part 4 of the copper interconnection strip 2 is directly connected to the copper interconnection strip 2, and the contact resistance of this interconnection mode is lower than that of the silver grid line 2 connected to the interconnection strip 2 by printing silver paste, so that the current conversion efficiency is better, that is, the conversion efficiency of the whole battery assembly is improved.

[0092] The utility model discloses a battery piece is provided with the copper metal connecting portion connected with the metal grid line, and the copper quality interconnect strip is directly folded on the copper metal connecting portion in alignment, thereby after the connection and fixation of the copper quality interconnect strip and the copper metal connecting portion, the copper metal portion on the battery piece and the copper quality interconnect strip form the structure of direct copper copper interconnection, compared with the mode of connecting the battery piece and the interconnect strip through soldering in the conventional technical scheme, the copper copper direct butt joint interconnection mode of the utility model does not exist the situation that the both contact badly, thereby guaranteeing the conversion efficiency of the battery assembly, compared with the connection of the interconnect strip and the grid line of the metal formed by printing silver paste in the conventional technology, the copper copper direct butt joint interconnection structure of the utility model has lower contact resistance, and thus can further improve the current collection amount and the current collection efficiency, thereby further improving the conversion efficiency of the battery assembly.

[0093] In addition, in the conventional technology, for the battery piece, after the completion of the battery piece manufacturing, the appearance, color and electrical property are classified and selected, and then the battery piece is packaged and delivered to the company for lamination. In order to reduce the cost, and to better match the battery piece with other components of the battery assembly to achieve more efficient solar energy conversion, and to make the battery assembly as a whole lighter and thinner to facilitate subsequent assembly transportation and installation, the thickness of the battery piece is continuously thinned. However, there are uncontrollable factors in the delivery process or the packaging and storage conditions. More importantly, the thinned battery piece is prone to hidden cracks or even direct breakage. Moreover, during transportation, the battery pieces in the package are stacked together, and stress will be generated between the stacked battery pieces, which will cause or exacerbate the hidden cracks of the battery pieces. In other words, the thinning of the battery piece may cause or exacerbate the hidden cracks of the battery piece during transportation, resulting in damage to the battery piece, which will increase the production cost of the battery assembly. In the present utility model, the battery piece 1 and the interconnect strip 2 are pre-connected before the assembly lamination, and then the pre-connected battery piece 1, interconnect strip 2 and other components of the battery assembly are laminated. In this way, during transportation, the battery piece 1 is no longer transported alone, and the pre-connected battery piece 1 and interconnect strip 2 are transported as a whole. Compared with the single battery piece 1, the overall thickness of the pre-connected battery piece 1 and interconnect strip 2 is thicker, and the interconnect strip 2 pre-connected with the battery piece 1 can also disperse the stress generated by the stacking of the battery piece 1. Therefore, the occurrence of hidden cracks of the battery piece 1 during transportation can be reduced, i.e. the damage to the battery piece 1 during transportation can be reduced, thereby reducing the overall manufacturing cost of the battery assembly.

[0094] The above embodiments of the utility model have been described in detail, but the content described is only the preferred embodiment of the utility model, and cannot be considered as limiting the scope of the utility model. Any equivalent changes and improvements made within the scope of the utility model application shall still belong to the patent coverage of the utility model.

Claims

1. A battery cell, wherein the battery cell is provided with metal grid lines, characterized in that: The battery cell is also provided with a copper metal connection part, which is connected to the metal grid line.

2. The battery cell according to claim 1, characterized in that: Among the metal grid lines extending along the length of the battery cell, at least one metal grid line is configured as the copper metal connection portion, and the width of the metal grid line configured as the metal connection portion is greater than that of the other metal grid lines; or, among the metal grid lines extending along the length of the battery cell, the width of at least one grid line at at least one location is greater than the width of the metal grid line at other locations, and the location with the larger width on the metal grid line forms a copper metal connection portion; or, multiple copper metal connection portions are spaced apart, and the multiple copper metal connection portions are distributed in a grid pattern, and the multiple copper metal connection portions located on the same straight line are connected by metal grid lines in the straight line direction, and the width of the copper metal connection portion is greater than the width of the metal grid line.

3. The battery cell according to claim 2, characterized in that: When one or more copper metal connectors are provided, each copper metal connector is located at the intersection of a metal grid line extending horizontally along the cell and a metal grid line extending along the cell width.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The height of the copper metal connector is equal to the height of the metal grid line.

5. The battery cell according to claim 3, characterized in that: An antioxidant layer is provided on the outer surface of the copper metal connector.

6. The battery cell according to any one of claims 1 to 3 and 5, characterized in that: The metal grid lines are configured as copper metal grid lines or the topmost layer of the metal grid lines is a copper plating layer.

7. The battery cell according to claim 4, characterized in that: The metal grid lines are configured as copper metal grid lines or the topmost layer of the metal grid lines is a copper plating layer.

8. A battery assembly, characterized in that: It includes copper interconnect strips and a battery cell according to any one of claims 1 to 7, wherein the copper interconnect strips are aligned and stacked on a copper metal connector and connected to the copper metal connector.

9. The battery assembly according to claim 8, characterized in that: The upper surface of the copper metal connector is provided with two spaced thermosetting adhesives, the interconnecting strip is aligned and stacked between the two spaced thermosetting adhesives, and the copper metal connector and the interconnecting strip are connected by the thermosetting adhesives.

10. The battery assembly according to claim 9, characterized in that: The thickness of the thermosetting adhesive does not exceed the height of the interconnect strip.

11. The battery assembly according to claim 10, characterized in that: The thickness of the thermosetting adhesive is set to 5-50 μm.

12. The battery assembly according to claim 8, characterized in that: Flux is provided on the upper side of the copper metal connector and on both sides of the copper interconnect strip, and the flux is in contact with both sides of the copper interconnect strip. The copper metal connector and the copper interconnect strip are welded together by the flux.

13. The battery assembly according to claim 12, characterized in that: The thickness of the flux does not exceed the height of the copper interconnect strip.

14. The battery assembly according to claim 8, characterized in that: The copper interconnect strip is covered with a fusion strip at least at the portion that is connected to the copper metal connection part, and the copper interconnect strip is connected to the copper metal connection part at least through the fusion strip.

15. The battery assembly according to claim 14, characterized in that: The adhesive strip includes a body and attachment portions extending outward from both sides of the body. The body covers the upper side of the interconnect strip, and the two attachment portions, at their ends away from the body, extend downward along both sides of the interconnect strip and the copper metal connection portion and contact the surface of the battery cell.

16. The battery assembly according to any one of claims 8 to 15, characterized in that: An antioxidant protective layer is also provided on the interconnecting strip.

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