Battery piece, battery string and photovoltaic module

Abstract

The utility model discloses a battery piece, a battery string and a photovoltaic assembly. The battery piece comprises a substrate; the auxiliary grid lines are arranged on the surface of the substrate, grooves used for containing or connecting electric connecting pieces are formed in the auxiliary grid lines, and the grooves extend in the first direction of the substrate and penetrate through the auxiliary grid lines in the second direction of the substrate; the groove is an arc-shaped groove with a lower middle part and two higher ends in the third direction of the substrate, and the first direction, the second direction and the third direction of the substrate are respectively perpendicular to each other. Therefore, by arranging the battery piece, the contact area of the auxiliary grid line and the electric connecting piece can be increased, so that the contact resistance between the auxiliary grid line and the electric connecting piece is reduced, the power of the battery piece is improved, the connection strength between the auxiliary grid line and the electric connecting piece can be improved, and the grid breaking problem caused by damage of auxiliary grid line slurry in the connection process of the auxiliary grid line and the electric connecting piece is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic module field especially a kind of cell piece, cell string and photovoltaic module. BACKGROUND

[0002] With the continuous development of photovoltaic technology and the continuous change of market demand, 0BB (Zero Busbar Technology, i.e. no main grid design) technology has become one of the mainstream technologies in the photovoltaic industry. The cell piece using 0BB technology has no pad on the front and back surfaces, which reduces the light-shielding area of the cell surface, improves the conversion efficiency of the cell and the power of the module, and reduces the cost of silver consumption of the electrode. For the 0BB scheme of "welding first and printing later", under the condition of no pad and main grid connecting line, it is challenging to ensure a certain tension and good ohmic contact between the solder strip and the electrode of the cell piece.

[0003] In the related art, with the introduction of silver-copper paste into heterojunction cells, the silver-copper paste at the soldering position of the solder strip is prone to expose copper particles, and even direct disconnection of the grid after welding, thereby reducing the performance of the product. SUMMARY

[0004] The utility model aims at at least one of the technical problems existing in the prior art. To this end, one object of the utility model is to provide a cell piece that can increase the contact area of the sub-grid line and the electrical connector, thereby reducing the contact resistance between the sub-grid line and the electrical connector, improving the power of the cell piece, and also improving the connection strength between the two, and improving the problem of disconnection of the grid caused by damage to the sub-grid line paste during the connection of the sub-grid line and the electrical connector.

[0005] The utility model further provides a cell string.

[0006] The utility model still further provides a photovoltaic module.

[0007] According to the cell piece of the first aspect of the utility model, the cell piece comprises: a substrate; a sub-grid line, the sub-grid line is arranged on the surface of the substrate, the sub-grid line is formed with a groove for accommodating or connecting an electrical connector, the groove extends in a first direction of the substrate and penetrates the sub-grid line in a second direction of the substrate, the groove is configured as an arc-shaped groove with low middle and high ends in a third direction of the substrate, and the first direction, the second direction and the third direction of the substrate are perpendicular to each other.

[0008] Therefore, by providing the cell piece, the contact area of the sub-grid line and the electrical connector can be increased, thereby reducing the contact resistance between the sub-grid line and the electrical connector, improving the power of the cell piece, and also improving the connection strength between the two, and improving the problem of disconnection of the grid caused by damage to the sub-grid line paste during the connection of the sub-grid line and the electrical connector.

[0009] In some examples of the utility model, the distance from the lowest point of the groove to the substrate is d1, d1 satisfies the relationship: 3 μm≤d1≤5 μm; and / or the distance from the highest point of the groove to the substrate is d2, d2 satisfies the relationship: 10 μm≤d2≤17 μm.

[0010] In some examples of the utility model, the distance from the lowest point of the groove to the substrate is d1, the distance from the highest point of the groove to the substrate is d2, d1 and d2 satisfy the relationship: 5 μm≤d2-d1≤15 μm.

[0011] In some examples of the utility model, the secondary grid line comprises: a plurality of first electrode parts, the plurality of first electrode parts are spaced apart in a first direction of the substrate; a plurality of second electrode parts, the plurality of second electrode parts are spaced apart in the first direction of the substrate, and each second electrode part is connected between two adjacent first electrode parts; and / or the width of the second electrode part is greater than the width of the first electrode part, and the second electrode part is formed with the groove.

[0012] In some examples of the utility model, the first electrode part is one of a copper grid line and a silver-copper grid line, and the second electrode part is one of a silver grid line and a silver-copper grid line.

[0013] In some examples of the utility model, the end of the second electrode part is covered on the end of the adjacent first electrode part and is stacked in a third direction of the substrate.

[0014] In some examples of the utility model, the distance between two adjacent first electrode parts is d3, d3 satisfies the relationship: 300 μm≤d3≤600 μm; and / or the distance from the top surface of the first electrode part to the substrate is d4, the distance from the top surface of the second electrode part on one side of the groove to the substrate is d5, and d4 and d5 satisfy the relationship: d4

[0015] In some examples of the utility model, the secondary grid line is a plurality of, the plurality of secondary grid lines are spaced apart on the substrate along a second direction of the substrate, and the grooves of the plurality of secondary grid lines are arranged in a matrix manner for respectively accommodating and connecting a plurality of electrical connectors.

[0016] The battery string according to the second aspect of the utility model comprises: a plurality of battery pieces according to the first aspect of the utility model; and an electrical connector, which is at least partially arranged between two adjacent battery pieces and at least partially located in the groove and connected with the groove.

[0017] The photovoltaic module according to the third aspect of the present application comprises: the battery string according to the first aspect of the present application.

[0018] Additional aspects and advantages of the present application will be described in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, taken in conjunction with the following drawings, in which:

[0020] Figure 1 is a structural schematic view of a first electrode part on a substrate according to an embodiment of the present application;

[0021] Figure 2 is a structural schematic view of a second electrode part on a substrate according to an embodiment of the present application;

[0022] Figure 3 is a top view of a battery piece according to an embodiment of the present application;

[0023] Figure 4 is a sectional view of a battery piece according to an embodiment of the present application.

[0024] REFERENCE NUMERALS:

[0025] 100, battery piece;

[0026] 1, substrate; 2, auxiliary grid line; 21, first electrode part; 22, second electrode part; 221, groove;

[0027] 201, electrical connecting piece. DETAILED DESCRIPTION

[0028] The embodiments of the present application will be described in detail below, and the embodiments described with reference to the drawings are exemplary, and the embodiments of the present application will be described in detail below.

[0029] The embodiments of the present application will be described below with reference to Figures 1-4 The battery piece 100 according to the embodiments of the present application can increase the contact area of the auxiliary grid line 2 and the electrical connecting piece 201, thereby reducing the contact resistance between the auxiliary grid line 2 and the electrical connecting piece 201, improving the power of the battery piece 100, and also improving the connection strength between the two, and improving the problem of broken grid caused by the destruction of the auxiliary grid line 2 paste during the connection process of the auxiliary grid line 2 and the electrical connecting piece 201.

[0030] In combination with Figures 1-4As shown, the battery piece 100 according to the first aspect of the present application comprises a substrate 1 and a sub-grid line 2. Wherein, the battery piece 100 is a basic unit for converting light energy into electrical energy; the substrate 1 usually has semiconductor properties, and can convert photon energy into electron-hole pairs through photoelectric effect (that is, when a photon with a certain energy is irradiated to the surface of the semiconductor substrate 1, if the energy of the photon is greater than or equal to the band gap energy of the semiconductor, the photon will be absorbed, and after absorbing the photon, the electron in the valence band obtains enough energy to transition to the conduction band, forming a free electron and a hole left in the valence band, that is, an electron-hole pair, in a p-n junction or other type of heterojunction, there is a built-in electric field, which will quickly separate the generated electron-hole pair to prevent them from recombining, the separated electrons move to the n region, and the holes move to the p region, forming a current in the external circuit, which is the photocurrent); the sub-grid line 2 is located on the light receiving surface of the battery piece 100 for collecting current.

[0031] Specifically, the sub-grid line 2 is arranged on the surface of the substrate 1, the sub-grid line 2 is formed with a groove 221, the groove 221 can be used to accommodate or connect the electrical connector 201, the groove 221 extends in the first direction of the substrate 1, and the groove 221 penetrates the sub-grid line 2 in the second direction of the substrate 1, the groove 221 is configured as an arc-shaped groove 221 with low middle and high ends in the third direction of the substrate 1, and the first direction, the second direction and the third direction are perpendicular to each other.

[0032] Specifically, the sub-grid line 2 is arranged on one side surface of the substrate 1 in the third direction, and the sub-grid line 2 is formed with a groove 221 recessed towards the substrate 1. Therefore, the length extension direction of the sub-grid line 2 intersects with the penetration direction of the groove 221, which is beneficial to reduce the mutual influence between the sub-grid line 2 and the electrical connector 201 accommodated in the groove 221, thereby improving the connection regularity and electrical connection stability of the battery piece 100.

[0033] Wherein, along the third direction of the substrate 1, the longitudinal cross-sectional shape of the groove 221 is configured as an arc shape, which is beneficial to increase the contact fitting area between the electrical connector 201 which is at least partially arc-shaped in the circumferential direction and the groove 221, for example, the electrical connector 201 (such as a solder strip) with a circular cross-section, that is, to increase the connection fitting degree of the electrical connector 201 and the groove 221, and also beneficial to increase the connection stability of the electrical connector 201 in the groove 221.

[0034] In addition, the electric connecting piece 201 (such as a solder strip) can be welded in the groove 221 of the auxiliary grid line 2 by welding, and when the groove 221 is configured as an arc shape with low middle and high two ends, this is beneficial to increase the contact area between the auxiliary grid line 2 and the electric connecting piece 201, thereby reducing the contact resistance between the auxiliary grid line 2 and the electric connecting piece 201 (when passing through the current on the mechanical contact surface of two conductors, the resistance of the interface part is higher than that of other parts, and this resistance is called contact resistance), and improving the power of the battery piece 100; and the welding tensile force between the auxiliary grid line 2 and the electric connecting piece 201 can also be improved, thereby improving the structural strength of the auxiliary grid line 2.

[0035] For example, the electric connecting piece 201 can be a solder strip (such as solder), and when the solder is fused with the paste of the auxiliary grid line 2 during welding, the paste on both ends will converge to the position of the solder strip, which is easy to cause the grid line on both sides to be broken. Compared with the traditional straight auxiliary grid line, the auxiliary grid line 2 in the present case is welded with the solder strip through the arc-shaped groove 221, so that the contact area between the auxiliary grid line 2 and the solder strip can be increased, and the problem of broken grid caused by the convergence of the paste on both sides of the solder strip after being melted to the solder strip can be avoided.

[0036] Therefore, by arranging the battery piece 100, the contact area between the auxiliary grid line 2 and the electric connecting piece 201 can be increased, thereby reducing the contact resistance between the auxiliary grid line 2 and the electric connecting piece 201, improving the power of the battery piece 100, and also improving the connection strength between the two, and improving the problem of broken grid caused by the paste of the auxiliary grid line 2 being damaged during the connection process of the auxiliary grid line 2 and the electric connecting piece 201.

[0037] According to some embodiments of the present application, in combination with Figure 4 As shown in FIG. 1, the distance from the lowest point of the groove 221 to the substrate 1 is d1, and d1 satisfies the relationship: 3μm≤d1≤5μm. Wherein, the distance from the lowest point of the groove 221 to the substrate 1 is small, so that the auxiliary grid line 2 can be effectively connected with the electric connecting piece 201 at the lowest position of the groove 221, thereby reducing the risk of broken grid of the auxiliary grid line 2 and improving the conductivity of the auxiliary grid line 2 during use. For example, the distance d1 from the lowest point of the groove 221 to the substrate 1 can be 3μm, 3.5μm, 4μm and 5μm, but is not limited thereto.

[0038] Optionally, the distance from the highest point of the groove 221 to the substrate 1 is d2, and d2 satisfies the relationship: 10μm≤d2≤17μm, so as to arrange the groove 221 into a shape with high sides and low middle, thereby as far as possible to improve the contact area between the groove 221 and the electric connecting piece 201, reduce the contact resistance between the two, improve the connection strength of the auxiliary grid line 2, and further improve the power of the battery piece 100 and reduce the risk of broken grid. For example, the distance d2 from the highest point of the groove 221 to the substrate 1 can be 10μm, 12μm, 15μm and 17μm, but is not limited thereto.

[0039] According to some optional embodiments of the present application, in combination with Figure 4 As shown in the figure, the distance from the lowest point of the groove 221 to the substrate 1 is d1, and the distance from the highest point of the groove 221 to the substrate 1 is d2, and d1 and d2 satisfy the relationship: 5μm≤d2-d1≤15μm.

[0040] As arranged above, the difference between the distance from the lowest point of the groove 221 to the substrate 1 and the distance from the highest point of the groove 221 to the substrate 1 is within a reasonable range, which on the one hand can avoid the risk of the battery piece 100 being easily cracked after being stacked due to too large distance difference, and on the other hand can also avoid the cost of the secondary grid line 2 being too large due to the distance from the highest point of the groove 221 to the substrate 1 being too large, thereby reducing the cost of the battery piece 100, and on the other hand can also increase the contact area of the secondary grid line 2 and the electrical connecting piece 201 by using the structural characteristics of the groove 221, thereby reducing the contact resistance and improving the connection strength. For example, the difference between the distance d1 from the lowest point of the groove 221 to the substrate 1 and the distance d2 from the highest point of the groove 221 to the substrate 1 can be 5μm, 8μm, 10μm and 15μm, without being limited thereto.

[0041] According to some optional embodiments of the present application, in combination with Figure 4 As shown in the figure, the secondary grid line 2 includes a plurality of first electrode parts 21 and a plurality of second electrode parts 22, the plurality of first electrode parts 21 are distributed at intervals in the first direction of the substrate 1, the plurality of second electrode parts 22 are distributed at intervals in the first direction of the substrate 1, and each second electrode part 22 is connected between two adjacent first electrode parts 21, wherein the width of the second electrode part 22 is greater than the width of the first electrode part 21, and the second electrode part 22 is formed with the groove 221.

[0042] Among them, the first electrode part 21 and the second electrode part 22 are distributed at intervals along the first direction of the substrate 1, and each second electrode part 22 is connected between two adjacent first electrode parts 21, which is conducive to the first electrode part 21 and the second electrode part 22 forming a complete secondary grid line 2, thereby ensuring the smoothness of the current conduction in the entire secondary grid line 2. In addition, by splitting the secondary grid line 2 into the first electrode part 21 and the second electrode part 22 which are connected alternately, since the width of the second electrode part 22 is greater than the width of the first electrode part 21, the bearing strength of the second electrode part 22 is greater, so that under the premise of ensuring the overall communication of the secondary grid line 2, it is also conducive to connecting the electrical connecting piece 201 (such as a solder strip) on the second electrode part 22 with greater bearing strength, which can reduce the risk of grid breakage of the secondary grid line 2 in the process of connecting with the electrical connecting piece 201 (such as welding the solder strip on the groove 221), and also can use the first electrode part 21 with smaller width as a conductive carrier at the non-connection position of the secondary grid line 2 and the electrical connecting piece 201, thereby taking into account the economy and reliability of the secondary grid line 2 at the same time.

[0043] Alternatively, the first electrode part 21 can be a copper grid line, which is a grid line made of pure copper or mainly composed of copper, and has the characteristics of low cost and good conductivity. Thus, when the first electrode part 21 is a copper grid line, the material cost can be reduced on the basis of ensuring good conductivity, thereby improving the economy.

[0044] Alternatively, the first electrode part 21 can be a silver-copper grid line, which is generally a grid line formed by plating a layer of silver on a copper grid line or an alloy of silver and copper. Silver has better conductivity and oxidation resistance, and can also enhance the adhesion between the grid line and the silicon wafer. Thus, when the first electrode part 21 is a silver-copper grid line, the conductivity efficiency of the battery piece 100 can be improved, and the power output can be increased, because the silver-copper grid line can reduce resistance loss.

[0045] Alternatively, the second electrode part 22 can be a silver grid line. Silver has very high conductivity, which helps to minimize resistance loss and improve the power output efficiency of the battery piece 100. Silver can form a good ohmic contact with the substrate 1 (such as a silicon substrate), which is conducive to current collection. Silver has better conductivity and oxidation resistance, and is not easily oxidized in the environment, so it can maintain stability and high efficiency for a long time. The silver grid line has good mechanical strength and durability, which can ensure the structural stability during long-term use. Thus, when the second electrode part 22 is a silver grid line, the conductivity efficiency of the battery piece 100 can be effectively improved, and the structural stability of the auxiliary grid line 2 can be ensured, and the risk of grid breakage caused by welding can be reduced.

[0046] Alternatively, the second electrode part 22 is a silver-copper grid line, which can take into account both the structural strength and the material cost of the second electrode part 22, thereby improving its practicality.

[0047] For example, the electrical connector 201 in the case is a solder strip, and the first electrode part 21 and the second electrode part 22 can be spliced together using two different pastes. The first electrode part 21 is a short line segment, and silver-copper paste or pure copper paste is used. The part of the paste does not come into contact with the solder strip, and the solder tin does not react with the paste. This avoids the mutual solubility of silver and tin during high-temperature soldering, which causes the silver-copper powder to be exposed, reduces the risk of structural reliability of the battery piece 100, provides more space for the silver-copper paste to reduce the silver content, and thus reduces the material cost. The second electrode part 22 can use paste B with good solder resistance (such as pure silver paste or silver-copper paste with good solder resistance). The groove 221 of the second electrode part 22 corresponds to the soldering position of the solder strip, and this part of the paste provides more soldering tension when soldering with the solder strip. During the manufacturing process of the battery piece 100, paste A of the first electrode part 21 is printed first, and paste B of the second electrode part 22 is printed later. The overlapping part of the paste B of the first electrode part 21 and the second electrode part 22 overlaps the paste A. This increases the solder offset tolerance range, and even if there is a small amount of solder offset (within the overlapping width of the AB paste), the solder strip is in contact with the paste B, which avoids the destruction of the silver-copper powder particles in the paste A during soldering, thereby improving the structural reliability of the battery piece 100 and reducing the risk of grid breakage.

[0048] Further, as shown in Figure 4 , the end of the second electrode part 22 covers the end of the adjacent first electrode part 21, and the end of the second electrode part 22 and the end of the adjacent first electrode part 21 are stacked in the third direction of the substrate 1. This is advantageous in that the second electrode part 22 is directly stacked on the first electrode part 21 during the manufacturing process of the battery piece 100 to form a groove 221 shape with a high middle and low sides, thereby simplifying the processing technology. On the other hand, by overlapping the two ends of the second electrode part 22 above the ends of the adjacent first electrode part 21, the solder offset tolerance range of the electrical connector 201 (such as a solder strip) on the second electrode part 22 is improved, thereby improving the solder fault tolerance, reducing the risk of grid breakage due to high-temperature melting of the first electrode part 21 caused by solder offset, and thus reducing the manufacturing difficulty of the battery piece 100 and improving the conductivity reliability of the battery piece 100.

[0049] Alternatively, as shown in Figure 4 , the distance between the two adjacent first electrode parts 21 is d3, and d3 satisfies the relationship: 300 μm ≤ d3 ≤ 600 μm.

[0050] Wherein, since the width of the electrical connecting member 201 (such as a solder strip) is generally between 220-260 μm, the light-shielding area of the substrate 1 can be reduced as much as possible, and the distance d3 between the two adjacent first electrode portions 21 is greater than the width of the solder strip, since the second electrode portion 22 is connected between the adjacent first electrode portions 21, and the second electrode portion 22 needs to cover the width of the solder strip (i.e. the second electrode portion 22 needs to be greater than the width of the second electrode portion 22), thus unnecessary material consumption of the first electrode portion 21 can be avoided, thereby reducing the manufacturing cost of the battery tab 100. For example, the distance d3 between the two adjacent first electrode portions 21 can be 300 μm, 400 μm, 450 μm, and 600 μm, without being limited thereto.

[0051] Alternatively, the second electrode portion 22 can be connected to the first electrode portion 21 by a plurality of sub-grid lines 2. Figure 4 As shown, the distance from the top surface of the first electrode portion 21 to the substrate 1 is d4, and the distance from the top surface of the second electrode portion 22 located on one side of the groove 221 to the substrate 1 is d5, d4 and d5 satisfy the relationship: d4 < d5, thus the highest point of the groove 221 is higher than the highest point of the first electrode portion 21, which can prevent the electrical connecting member 201 from being connected to the first electrode portion 21 by mistake (if the highest point of the groove 221 is lower than the highest point of the first electrode portion 21, the electrical connecting member 201 is easy to be connected to the part of the first electrode portion 21 which is higher than the highest point of the groove 221), thereby ensuring the connection accuracy between the electrical connecting member 201 and the groove 221.

[0052] According to some optional embodiments of the present application, the second electrode portion 22 can be connected to the first electrode portion 21 by a plurality of sub-grid lines 2. Figure 3 As shown, the plurality of sub-grid lines 2 are arranged on the substrate 1 in the second direction of the substrate 1, and the grooves 221 of the plurality of sub-grid lines 2 are arranged in a matrix manner for respectively accommodating and connecting the plurality of electrical connecting members 201. Figure 4 Specifically, the plurality of sub-grid lines 2 collectively collect the current on the substrate 1, thus the transmission efficiency of the current on the substrate 1 can be improved, thereby improving the power of the battery tab 100; and the grooves 221 of the plurality of sub-grid lines 2 are arranged in a matrix manner, thus the arrangement regularity of the grooves 221 can be improved, thereby improving the manufacturing property.

[0053] According to the second aspect of the present application, the battery string comprises a plurality of the above-mentioned battery tabs 100 and the electrical connecting member 201, the electrical connecting member 201 is at least partially arranged between the two adjacent battery tabs 100, the electrical connecting member 201 is at least partially located in the groove 221, and the electrical connecting member 201 is connected with the groove 221.

[0054]

[0055] ​The battery string comprises a plurality of battery pieces 100 and electrical connecting pieces 201, at least part of the electrical connecting pieces 201 are connected with two adjacent battery pieces 100 respectively, so that the current collected by the busbar 2 from the substrate 1 is transmitted to the adjacent battery piece 100 through the electrical connecting piece 201, and the plurality of battery pieces 100 are connected in series through the electrical connecting piece 201, thereby improving the photoelectric conversion power. In addition, the electrical connecting piece 201 is at least partially connected in the groove 221, so that the contact resistance between the battery pieces 100 is reduced, and the welding tension between the busbars 2 on the adjacent battery pieces 100 is improved, thereby improving the photoelectric conversion efficiency of the battery string and the electrical conductivity reliability of the battery string.

[0056] The photovoltaic module according to the third aspect of the present application comprises the battery string of the above-mentioned embodiments, so that the photovoltaic module with the battery string can reduce the contact resistance between the electrical connecting piece 201 and the busbar 2, and can also reduce the risk of broken busbar of the busbar 2 in the welding process of the welding ribbon, thereby increasing the transmission efficiency of the current between the battery strings and improving the problem of broken busbar caused by the melting of the paste of the busbar 2 in the welding process.

[0057] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0058] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0059] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description of the above terms does not necessarily refer to the same embodiment or example.

[0060] Although the embodiments of the present application have been shown and described, it should be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made in the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

[0061] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0062] Although the embodiments of the present application have been shown and described, it should be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made in the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell (100), characterized by, The substrate (1) comprises: A sub-grid line (2) is arranged on the surface of the substrate (1), and a groove (221) for accommodating or connecting an electrical connector (201) is formed on the sub-grid line (2). The groove (221) extends in a first direction of the substrate (1) and penetrates the sub-grid line (2) in a second direction of the substrate (1). The groove (221) is configured as an arc-shaped groove (221) with a low middle and high ends in a third direction of the substrate (1). The first direction, the second direction and the third direction of the substrate (1) are perpendicular to each other. The distance from the lowest point of the groove (221) to the substrate (1) is d1, and d1 satisfies the relationship: 3μm≤d1≤5μm; and / or 2. The battery sheet (100) according to claim 1, characterized in that, The distance from the highest point of the groove (221) to the substrate (1) is d2, and d2 satisfies the relationship: 10μm≤d2≤17μm. The distance from the lowest point of the groove (221) to the substrate (1) is d1, and the distance from the highest point of the groove (221) to the substrate (1) is d2, and d1 and d2 satisfy the relationship: 5μm≤d2-d1≤15μm.

3. The battery sheet (100) according to claim 1, characterized in that, The sub-grid line (2) comprises:

4. The battery sheet (100) according to claim 1, characterized in that, A plurality of first electrode parts (21) are arranged in the first direction of the substrate (1); A plurality of second electrode parts (22) are arranged in the first direction of the substrate (1), and each second electrode part (22) is connected between two adjacent first electrode parts (21); and / or The width of the second electrode part (22) is greater than the width of the first electrode part (21), and the groove (221) is formed on the second electrode part (22). The first electrode part (21) is one of a copper grid line and a silver-copper grid line, and the second electrode part (22) is one of a silver grid line and a silver-copper grid line.

5. The battery sheet (100) according to claim 4, characterized in that The end of the second electrode part (22) covers the end of the adjacent first electrode part (21) and is arranged in the third direction of the substrate (1).

6. The battery sheet (100) according to claim 4, characterized in that The distance between two adjacent first electrode parts (21) is d3, and d3 satisfies the relationship: 300μm≤d3≤600μm; and / or 7. The battery sheet (100) according to claim 4, characterized in that, The distance from the top surface of the first electrode part (21) to the substrate (1) is d4, and the distance from the top surface of the second electrode part (22) on one side of the groove (221) to the substrate (1) is d5, and d4 and d5 satisfy the relationship: d4 The sub-grid line (2) is a plurality of sub-grid lines (2), and the plurality of sub-grid lines (2) are arranged in the second direction of the substrate (1) on the substrate (1). The grooves (221) of the plurality of sub-grid lines (2) are arranged in a matrix manner for respectively accommodating and connecting a plurality of electrical connectors (201).

8. The battery sheet (100) according to any one of claims 1-7, characterized in that, The substrate (1) comprises:

9. A battery string, characterized by A plurality of battery pieces (100) according to any one of claims 1-8. ​ An electrical connecting piece (201) is arranged at least partially between two adjacent battery pieces (100), and is at least partially located in and connected with a groove (221).

10. A photovoltaic module, characterized by Comprising: The battery string of claim 9.

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