Tab-free battery cells and battery modules

Abstract

The present invention relates to the field of power batteries, and discloses a tab-free battery cell and a battery module. The tab-free battery cell comprises a shell and a battery cell body, and the battery cell body comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet are separated by a diaphragm, the positive electrode sheet is connected to the positive electrode connection area, the negative electrode sheet is connected to the negative electrode connection area, the positive electrode sheet is provided with a plurality of positive electrode material parts, the negative electrode sheet is provided with a plurality of negative electrode material parts, and part of the shell is made of photoconductive material. The battery module comprises a plurality of the above-mentioned tab-free battery cells. In the battery cell provided in the present application, the positive electrode sheet and the negative electrode sheet are directly in contact with the shell respectively, and then the current is led out through the shell, without the need to provide a tab structure, thereby ensuring the sealing effect of the shell and avoiding the risk of leakage. At the same time, the manufacturing process of the tab structure is reduced, the production complexity is reduced, and the space occupied inside the shell is reduced, thereby improving the volume energy density of the battery cell and the module.

Description

Technical Field

[0001] The present invention relates to the field of power batteries, and in particular to a tab-free battery cell and a battery module. Background Art

[0002] With the increasing environmental and energy issues in recent years, new energy electric vehicles have gradually entered the public's field of vision. Lithium-ion power battery packs, as the main power source of new energy vehicles, have also received widespread attention. To achieve the extraction of positive and negative electrodes, existing battery structures have positive and negative tabs, and the current is extracted through the tabs inserted into the casing. This battery design has the following drawbacks:

[0003] (1) Due to the presence of the tabs, it is necessary to perform process packaging during battery production to prevent electrolyte leakage. However, it is impossible to essentially avoid 100% sealing of the packaging, and there is a risk of leakage;

[0004] (2) The tabs take up a certain amount of space, reducing the volume energy density of the battery and module;

[0005] (3) The existence of the tab structure increases the manufacturing process and increases the production complexity. Summary of the Invention

[0006] In order to solve the above technical problems or at least partially solve the above technical problems, the present invention provides a tab-free battery cell and a battery module.

[0007] The present invention provides a tab-free battery cell, comprising a shell and a battery cell body arranged inside the shell, wherein the shell is provided with a positive electrode connection area and a negative electrode connection area that can conduct electricity, wherein at least the portion of the shell provided with the positive electrode connection area and the negative electrode connection area is made of a photoconductive material, and the battery cell body comprises a positive electrode sheet and a negative electrode sheet that are relatively arranged, wherein the positive electrode sheet and the negative electrode sheet are separated by a diaphragm, the positive electrode sheet is connected to the positive electrode connection area, and the negative electrode sheet is connected to the negative electrode connection area.

[0008] Optionally, a plurality of positive electrode material portions are provided at intervals on the positive electrode plate, a plurality of negative electrode material portions are provided at intervals on the negative electrode plate, and the plurality of positive electrode material portions and the plurality of negative electrode material portions are alternately arranged.

[0009] Optionally, the positive electrode sheet includes a plurality of first positive electrode collectors arranged at intervals and a positive electrode collector junction area for connecting two adjacent first positive electrode collectors. The positive electrode collector junction area at the edge is connected to a positive electrode collector extension area for connecting to the positive electrode connection area. Positive electrode active materials are provided on both sides of the first positive electrode collector, and the first positive electrode collector and the positive electrode active materials constitute the positive electrode material part.

[0010] Optionally, the first positive current collector includes two positive current collector bodies, each of which has a first end and a second end relative to each other. The first ends of the two positive current collector bodies are connected, and the second ends of the two positive current collector bodies are respectively connected to the adjacent positive current collector junction areas.

[0011] Optionally, the positive electrode plate is formed by bending a plate coated with the positive electrode active material on one side, and the positive electrode active material is arranged at intervals along the length direction of the plate so that a first blank area is formed between two adjacent positive electrode active materials, and a second blank area is provided on the plate at one end, and the portion of the plate coated with the positive electrode active material is bent to form the positive electrode material portion, the portion of the plate corresponding to the first blank area forms the positive electrode collector junction area, and the portion of the plate corresponding to the second blank area is bent to form the positive electrode collector extension area.

[0012] Optionally, a portion of the electrode sheet coated with the positive electrode active material is bent to form the positive electrode material portion.

[0013] Optionally, a portion of the current collector corresponding to the positive electrode active material is bent to form the positive electrode current collector body, and the first ends of two adjacent positive electrode current collector bodies are connected through the first blank area.

[0014] Optionally, the distance of the first blank area along the length direction of the pole piece is L1, L1=2(A+B+C+D+X);

[0015] Among them, A is the thickness of the negative electrode active material, B is the thickness of the separator, C is the thickness of the positive electrode active material, D is the thickness of the first negative electrode current collector, and X is the 90° sheet metal unfolding length of the first positive electrode current collector; preferably, the distance of the first blank area along the length direction of the pole piece is less than 5 mm.

[0016] Optionally, the width of the positive electrode active material is smaller than the width of the first positive electrode current collector, so that a third blank area is formed on both sides of the electrode sheet, and the portion of the electrode sheet corresponding to the third blank area is bent toward the side of the electrode sheet not coated with the positive electrode active material.

[0017] Optionally, the dimension of the third blank area after bending in the width direction of the electrode is W1, wherein W1≤10mm; the horizontal distance between the end of the bent part of the third blank area and the connection between the third blank area and the positive electrode active material is W2, wherein W2≥0mm.

[0018] Optionally, the portion of the electrode corresponding to the third blank area is bent twice toward the side of the electrode not coated with the positive electrode active material, and the horizontal distance between the end of the bent portion and the connection between the third blank area and the positive electrode active material is W3, wherein W3 ≥ 0 mm.

[0019] Optionally, the negative electrode sheet includes a plurality of first negative electrode collectors arranged at intervals and a negative electrode collector junction area for connecting two adjacent first negative electrode collectors, the negative electrode collector junction area at the edge is connected to a negative electrode collector extension area for connecting to the negative electrode connection area, negative electrode active materials are provided on both sides of the first negative electrode collector, and the first negative electrode collector and the negative electrode active materials constitute the negative electrode material part.

[0020] Optionally, the first negative electrode current collector includes two negative electrode current collector bodies, each of which has a first end and a second end opposite to each other. The first ends of the two negative electrode current collector bodies are connected, and the second ends of the two negative electrode current collector bodies are respectively connected to the adjacent negative electrode current collector junction areas.

[0021] Optionally, the negative electrode plate is formed by bending a plate coated with the negative electrode active material on one side, and the negative electrode active material is arranged at intervals along the length direction of the plate so that a first blank area is formed between two adjacent negative electrode active materials, and a second blank area is provided on the plate at one end, and the portion of the plate coated with the negative electrode active material is bent to form the negative electrode material portion, the portion of the plate corresponding to the first blank area forms the negative electrode collector junction area, and the portion of the plate corresponding to the second blank area is bent to form the negative electrode collector extension area.

[0022] Optionally, a portion of the electrode sheet coated with the negative electrode active material is bent to form the negative electrode material portion.

[0023] Optionally, a portion of the current collector corresponding to the negative electrode active material is bent to form the negative electrode current collector body, and the first ends of two adjacent negative electrode current collector bodies are connected through the first blank area.

[0024] Optionally, the distance of the first blank area along the length direction of the pole piece is L2, L2=2(A+B+C+E+Y);

[0025] Wherein, A is the thickness of the negative electrode active material, B is the thickness of the separator, C is the thickness of the positive electrode active material, E is the thickness of the first positive electrode current collector, and Y is the 90° sheet metal unfolding length of the first negative electrode current collector.

[0026] Optionally, the distance of the first blank area along the length direction of the pole piece is less than 5 mm.

[0027] Optionally, the width of the negative electrode active material is smaller than the width of the first negative electrode current collector, so that a third blank area is formed on both sides of the electrode sheet, and the portion of the electrode sheet corresponding to the third blank area is bent toward the side of the electrode sheet not coated with the negative electrode active material.

[0028] Optionally, the dimension of the third blank area after bending in the width direction of the electrode is W1, wherein W1≤10mm; the horizontal distance between the end of the bent part of the third blank area and the connection between the third blank area and the negative electrode active material is W2, wherein W2≥0mm.

[0029] Optionally, the portion of the electrode corresponding to the third blank area is bent twice toward the side of the electrode not coated with the negative electrode active material, and the horizontal distance between the end of the bent portion and the connection between the third blank area and the negative electrode active material is W3, where W3 ≥ 0 mm.

[0030] Optionally, the positive electrode connection region and the negative electrode connection region are respectively provided with conductive glue connected to the positive electrode plate and the negative electrode plate.

[0031] Optionally, a bending portion is provided at the connection between the positive electrode sheet, the negative electrode sheet and the shell.

[0032] Optionally, the bending portion is configured to have two bends, such that the edges of the positive electrode sheet and the negative electrode sheet are wrapped inside the bending portion.

[0033] Optionally, the diaphragm extends to a side of the positive electrode sheet and the negative electrode sheet corresponding to the shell.

[0034] Optionally, a light-shielding film is provided on the outer periphery of the shell, and the light-shielding film is configured to allow the positive electrode connection area and the negative electrode connection area to be exposed.

[0035] The present invention also provides a battery module comprising a plurality of the above-mentioned tab-free battery cells.

[0036] Optionally, a transparent conductive film is provided between two adjacent shells and between the shell and the positive terminal and the negative terminal of the battery module, respectively, and an incident light source is provided on the transparent conductive film.

[0037] Optionally, light scattering particles are doped into the transparent conductive film.

[0038] Optionally, conductive glue is provided between the shell and the transparent conductive film, and between the transparent conductive film and the positive terminal and the negative terminal of the battery module.

[0039] Optionally, the conductive glue between the shell and the transparent conductive film is made of transparent material.

[0040] Optionally, a light-shielding coating is provided on the outer surface of the transparent conductive film, and the light-shielding coating is configured to expose portions of the transparent conductive film corresponding to the positive electrode connection region, the negative electrode connection region and the incident light source.

[0041] Optionally, the positive terminal and the negative terminal are respectively provided with elastic components for connecting to the outer shell of the battery module.

[0042] Optionally, a plurality of the tab-free battery cells are connected in series to form the battery module, and the transparent conductive film is provided between two adjacent tab-free battery cells.

[0043] Optionally, a plurality of the tab-free battery cells are connected in parallel to form the battery module, and the same sides of the plurality of tab-free battery cells are connected through the transparent conductive film.

[0044] Optionally, a plurality of the tab-free battery cells are connected in series and in parallel to form the battery module, and the transparent conductive film is provided between two adjacent tab-free battery cells arranged in series; and a plurality of the tab-free battery cells arranged in parallel are connected via the transparent conductive film.

[0045] Optionally, a heat dissipation structure is provided inside the battery module for dissipating heat.

[0046] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0047] In the battery cell provided by the present application, the positive electrode plate and the negative electrode plate are directly in contact with the shell respectively, and the current is then led out through the shell. There is no need to set up a pole ear structure, thereby ensuring the sealing effect of the shell and avoiding the risk of leakage. At the same time, the production process of the pole ear structure is reduced, the production complexity is reduced, and the space occupied inside the shell is reduced. It also reduces the space occupied by the series and parallel lines during the assembly of the battery module, thereby improving the volume energy density of the battery cell and the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0050] Figure 1 Schematic diagram of the structure of the tab-free battery cell according to an embodiment of the present invention;

[0051] Figure 2 Schematic diagram of a tab-free battery cell when the diaphragm is extended according to an embodiment of the present invention;

[0052] Figure 3 Schematic diagram of a tab-free battery cell when the first positive electrode current collector and the first negative electrode current collector are arranged in a V-shape in an embodiment of the present invention;

[0053] Figure 4 Schematic diagram of the tab-free battery cell with two bent portions according to an embodiment of the present invention;

[0054] Figure 5 This is a front view of the electrode sheet coated with a positive electrode active material according to an embodiment of the present invention;

[0055] Figure 6 A top view of the electrode sheet coated with a positive electrode active material according to an embodiment of the present invention;

[0056] Figure 7 This is a left side view of the electrode sheet coated with a positive electrode active material according to an embodiment of the present invention;

[0057] Figure 8 This is a left view of the pole piece when the third blank area is bent twice according to an embodiment of the present invention;

[0058] Figure 9 This is a cross-sectional view of the tab-free battery cell described in the embodiment of the present invention;

[0059] Figure 10 Schematic diagram of the battery module when multiple tab-free battery cells are connected in series according to an embodiment of the present invention;

[0060] Figure 11 Schematic diagram of the battery module when multiple tab-free battery cells are connected in parallel according to an embodiment of the present invention;

[0061] Figure 12 Schematic diagram of the battery module when multiple tab-free battery cells are connected in series and parallel according to an embodiment of the present invention.

[0062] Description of Reference Numerals

[0063] 10. Tab-free battery cell; 20. Shell; 21. Positive electrode connection area; 22. Negative electrode connection area; 30. Positive electrode plate; 31. Positive electrode material portion; 32. First positive electrode current collector; 321. Positive electrode current collector body; 33. Positive electrode current collector junction area; 34. Positive electrode current collector extension area; 35. Positive electrode active material; 40. Negative electrode plate; 41. Negative electrode material portion; 42. First negative electrode current collector; 421. Negative electrode current collector body; 43. Negative electrode current collector junction area; 44. Negative electrode current collector extension area; 45. Negative electrode active material; 50. Diaphragm; 60. Electrode plate; 61. First blank area; 62. Second blank area; 63. Third blank area; 70. Bending portion; 80. Battery module; 81. Transparent conductive film; 82. Incident light source; 83. Positive terminal; 84. Negative terminal; 85. Elastic component. DETAILED DESCRIPTION

[0064] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0065] The following description sets forth many specific details to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the implementation methods in the specification are only part of the implementation methods of the present invention, not all of the implementation methods.

[0066] Combine Figures 1 to 4 As shown, the tab-free battery cell provided in the embodiment of the present invention includes a housing 20 and a battery cell body disposed inside the housing 20. In addition, the housing 20 should also be provided with electrolyte and other components required for the battery cell. The housing 20 is provided with a positive electrode connection area 21 and a negative electrode connection area 22 that can conduct electricity. At least the portion of the housing 20 provided with the positive electrode connection area 21 and the negative electrode connection area 22 is made of a photoconductive material. The battery cell body includes a positive electrode sheet 30 and a negative electrode sheet 40 that are disposed opposite to each other. The positive electrode sheet 30 and the negative electrode sheet 40 are separated by a separator 50. The positive electrode sheet 30 is connected to the positive electrode connection area 21, and the negative electrode sheet 40 is connected to the negative electrode connection area 22, so that the current is drawn out through the housing 20.

[0067] Preferably, a plurality of positive electrode material portions 31 are spaced apart on the positive electrode sheet 30, and a plurality of negative electrode material portions 41 are spaced apart on the negative electrode sheet 40, with the plurality of positive electrode material portions 31 and the plurality of negative electrode material portions 41 being alternately arranged. The separator 50 is arranged in such a manner as to separate at least two adjacent positive electrode material portions 31 and negative electrode material portions 41.

[0068] Preferably, the entire shell 20 of the tab-free battery cell is made of photoconductive material to increase the convenience of manufacturing the shell 20. At this time, a light-shielding film is provided on the periphery of the shell 20, and the light-shielding film is configured to expose the positive connection area 21 and the negative connection area 22 to facilitate the lead-out of current. Among them, photoconductive materials refer to those materials that have low electrical conductivity before being irradiated with light, but can generate certain carriers under photon excitation, and can transmit carriers under the action of an external electric field, thereby greatly improving their electrical conductivity. Since this material is conventional technology, no further description is made here. Further optimized, the material of the shell 20 contains at least one of amorphous selenium (a-Ae), mercury iodide (HgI2), lead iodide (PbI2), cadmium zinc telluride (CdZnTe, CZT), poly-CZT, PbO, PbS, PbSe, and PbTe.

[0069] Among them, when external conduction is required, light is radiated to the positive connection area 21 and the negative connection area 22 on the shell 20, so that the corresponding positive connection area 21 and the negative connection area 22 are converted from an insulating state or a weakly conductive state to a conductive state, and then the required external circuit is contacted with the positive connection area 21 and the negative connection area 22, thereby realizing charging of the battery cell and external power supply.

[0070] In the battery cell provided in the present application, the positive electrode plate 30 and the negative electrode plate 40 are directly in contact with the shell 20 respectively, and the current is then led out through the shell 20. There is no need to set up a pole ear structure, thereby ensuring the sealing effect of the shell 20 and avoiding the risk of leakage. At the same time, the manufacturing process of the pole ear structure is reduced, the production complexity is reduced, and the space occupied inside the shell 20 is reduced. It also reduces the space occupied by the series and parallel lines during the assembly of the battery module, thereby improving the volume energy density of the battery cell and the module.

[0071] In some embodiments, combined Figure 1 and Figure 2 As shown, the positive electrode sheet 30 includes a plurality of first positive electrode collectors 32 arranged at intervals and a positive electrode collector junction area 33 for connecting two adjacent first positive electrode collectors 32. The positive electrode collector junction area 33 at the edge is connected to a positive electrode collector extension area 34 for connecting to the positive electrode connection area 21. Positive electrode active materials 35 are provided on both sides of the first positive electrode collector 32. The first positive electrode collector 32 and the positive electrode active materials 35 constitute the positive electrode material part 31.

[0072] In other embodiments, combined Figure 3 and Figure 4As shown, the first positive current collector 32 includes two positive current collector bodies 321, each having a first end and a second end opposite each other. The first ends of the two positive current collector bodies 321 are connected, and the second ends of the two positive current collector bodies 321 are respectively connected to the adjacent positive current collector junction area 33, so that the first positive current collector 32 forms a V-shape. Positive active material 35 is provided on the outside of the positive current collector bodies 321. The second end of the first positive current collector body 321 is connected to the positive current collector extension area 34, while the first end of the last positive current collector body 321 is not connected.

[0073] In some embodiments, the positive electrode sheet 30 is formed by bending a sheet 60 coated with a positive electrode active material 35 on one side. Figure 5 and Figure 6 As shown, the positive electrode active materials 35 are spaced apart along the length direction of the electrode sheet 60 so that a first blank area 61 is formed between two adjacent positive electrode active materials 35, and a second blank area 62 is provided on the electrode sheet 60 at one end. The portion of the electrode sheet 60 coated with the positive electrode active material 35 is bent to form the positive electrode material portion 31, the portion of the electrode sheet 60 corresponding to the first blank area 61 forms the positive electrode current collector junction area 33, and the portion of the electrode sheet 60 corresponding to the second blank area 62 is bent to form the positive electrode current collector extension area 34.

[0074] Among them, if a double-sided coated pole piece 60 is used, the collector connection positions of multiple pole pieces 60 need to be connected by welding or other methods. However, the single-sided coating method adopted in this embodiment has already formed a connection between each pole piece 60 after coating, and the stability of the connection is better than that of welding or other connection methods. In addition, since this embodiment uses multiple single-sided coated pole pieces 60 connected together, compared with the pole pieces 60 of the laminated battery, each pole piece 60 reduces the need for cutting two edges, greatly reducing the generation of burrs during cutting, simplifying and optimizing the production process.

[0075] Specifically, the portion of the electrode sheet 60 coated with the positive electrode active material 35 is bent to form the positive electrode material portion 31. Further optimized, the portion of the current collector corresponding to the positive electrode active material 35 is bent to form the positive electrode current collector body 321. The first ends of two adjacent positive electrode current collector bodies 321 are connected by a first blank area 61, so that the two adjacent positive electrode current collector bodies 321 and the portion of the electrode sheet 60 corresponding to the first blank area 61 form a V-shape. This design facilitates the folding of the electrode sheet 60 in the first blank area 61, reserving bending space to avoid damage to the active material and preventing defects such as shedding and cracking.

[0076] The distance of the first blank area 61 along the length direction of the electrode 60 is L1, L1 = 2(A+B+C+D+X). Among them, A is the thickness of the negative electrode active material 45, B is the thickness of the separator 50, C is the thickness of the positive electrode active material 35, D is the thickness of the first negative electrode current collector 42, and X is the 90° sheet metal unfolding length of the first positive electrode current collector 32. Among them, the sheet metal unfolding length here is the bending allowance reserved in the length direction of the sheet before processing to achieve the required size when the flat sheet is bent. Preferably, the distance of the first blank area 61 along the length direction of the electrode 60 is less than 5mm, and should be greater than 0mm, so that the overall structure meets the design requirements.

[0077] Combine Figure 6 、 Figure 7 and Figure 8 As shown, the width of the positive electrode active material 35 is smaller than the width of the first positive electrode current collector 32, so that a third blank area 63 is formed on both sides of the electrode piece 60, and the portion of the electrode piece 60 corresponding to the third blank area 63 is bent toward the side of the electrode piece 60 that is not coated with the positive electrode active material 35, so as to ensure that the cutting edge does not contact the diaphragm 50, prevent the burrs on the cutting edge from piercing the diaphragm 50, and avoid internal short circuit, battery lithium deposition and other faults.

[0078] The dimension of the bent third blank area 63 in the width direction of the electrode sheet 60 is W1, where W1 is ≤ 10 mm, ensuring that the size of the electrode sheet 60 is minimized and the area of ​​the positive electrode active material 35 on the electrode sheet 60 is increased. The horizontal distance between the end of the bent portion of the third blank area 63 and the connection between the third blank area 63 and the positive electrode active material 35 is W2, where W2 is ≥ 0 mm, ensuring that the end of the bent portion does not exceed the edge of the positive electrode active material 35.

[0079] This design prevents the positive electrode sheet 30 from extending to the area of ​​the electrode sheet 60 corresponding to the positive electrode active material 35, ensuring that the overall thickness of the battery does not increase after the electrode sheet 60 is assembled, and avoiding uneven thickness of the battery cell caused by the setting of the bent part.

[0080] Further optimization, such as Figure 8 As shown, the portion of the electrode sheet 60 corresponding to the third blank area 63 is bent twice toward the side of the electrode sheet 60 not coated with the positive electrode active material 35. The horizontal distance between the end of the bent portion and the connection between the third blank area 63 and the positive electrode active material 35 is W3, where W3 ≥ 0 mm. This ensures that the trimmed edge is completely enclosed within the portion of the electrode sheet 60 corresponding to the third blank area 63. This design also avoids increasing the thickness of the battery cell and changing its thickness uniformity.

[0081] In some embodiments, combined Figure 1 and Figure 2As shown, the negative electrode sheet 40 includes a plurality of first negative electrode current collectors 42 arranged at intervals and a negative electrode current collector junction area 43 for connecting two adjacent first negative electrode current collectors 42. The negative electrode current collector junction area 43 at the edge is connected to a negative electrode current collector extension area 44 for connecting to the negative electrode connection area 22. Negative electrode active materials 45 are provided on both sides of the first negative electrode current collector 42. The first negative electrode current collector 42 and the negative electrode active materials 45 constitute a negative electrode material portion 41.

[0082] In other embodiments, combined Figure 3 and Figure 4 As shown, the first negative current collector 42 includes two negative current collector bodies 421, each having a first end and a second end opposite each other. The first ends of the two negative current collector bodies 421 are connected, and the second ends of the two negative current collector bodies 421 are respectively connected to the adjacent negative current collector junction area 43, so that the first positive current collector 32 forms a V-shape. Positive active material 35 is provided on the outside of the positive current collector bodies 321. The second end of the first negative current collector body 421 is connected to the negative current collector extension area 44, while the first end of the last negative current collector body 421 is not connected.

[0083] In some embodiments, the negative electrode plate 40 is formed by bending a plate 60 coated on a single side with a negative electrode active material 45. Specifically, the negative electrode active material 45 is spaced apart along the length of the plate 60, so that a first blank area 61 is formed between two adjacent negative electrode active materials 45. A second blank area 62 is provided on the plate 60 at one end. The portion of the plate 60 coated with the negative electrode active material 45 is bent to form the negative electrode material portion 41. The portion of the plate 60 corresponding to the first blank area 61 forms the negative current collector junction area 43, and the portion of the plate 60 corresponding to the second blank area 62 is bent to form the negative current collector extension area 44.

[0084] Among them, if a double-sided coated pole piece 60 is used, the collector connection positions of multiple pole pieces 60 need to be connected by welding or other methods. However, the single-sided coating method adopted in this embodiment has already formed a connection between each pole piece 60 after coating, and the stability of the connection is better than that of welding or other connection methods. In addition, since this embodiment uses multiple single-sided coated pole pieces 60 connected together, compared with the pole pieces 60 of the laminated battery, each pole piece 60 reduces the need for cutting two edges, greatly reducing the generation of burrs during cutting, simplifying and optimizing the production process.

[0085] Specifically, the portion of the electrode sheet 60 coated with the negative electrode active material 45 is bent to form the negative electrode material portion 41. Further optimized, the portion of the current collector corresponding to the negative electrode active material 45 is bent to form the negative electrode current collector body 421. The first ends of two adjacent negative electrode current collector bodies 421 are connected by a first blank area 61, so that the two adjacent negative electrode current collector bodies 421 and the portion of the electrode sheet 60 corresponding to the first blank area 61 form a V-shape. Similarly, this design facilitates the folding of the electrode sheet 60 in the first blank area 61, reserving bending space to avoid damage to the active material and preventing defects such as shedding and cracking.

[0086] like Figure 9 As shown, the distance of the first blank area 61 along the length direction of the electrode 60 is L2, L2 = 2 (A + B + C + E + Y). Among them, A is the thickness of the negative electrode active material 45, B is the thickness of the separator 50, C is the thickness of the positive electrode active material 35, E is the thickness of the first positive electrode current collector 32, and Y is the 90° sheet metal unfolding length of the first negative electrode current collector 42. Among them, the sheet metal unfolding length here is the bending allowance reserved in the length direction of the sheet before processing to achieve the required size when the flat sheet is bent. Preferably, the distance of the first blank area 61 along the length direction of the electrode 60 is less than 5mm, and should be greater than 0mm, so that the overall structure meets the design requirements.

[0087] The arrangement of the negative electrode active material 45 on the electrode sheet 60 is the same as the arrangement of the positive electrode active material 35 on the electrode sheet 60, and therefore, it is not shown in the accompanying drawings. Specifically, the width of the negative electrode active material 45 is less than the width of the first negative electrode current collector 42, so that a third blank area 63 is formed on both sides of the electrode sheet 60. The portion of the electrode sheet 60 corresponding to the third blank area 63 is bent toward the side of the electrode sheet 60 not coated with the negative electrode active material 45, so that the cut edge does not contact the separator 50, preventing burrs on the cut edge from piercing the separator 50, thereby avoiding internal short circuits, battery lithium deposition, and other faults.

[0088] The dimension of the bent third blank area 63 in the width direction of the electrode sheet 60 is W1, where W1 is ≤ 10 mm, ensuring that the size of the electrode sheet 60 is minimized and the area of ​​the negative electrode active material 45 on the electrode sheet 60 is increased. The horizontal distance between the end of the bent portion of the third blank area 63 and the connection between the third blank area 63 and the negative electrode active material 45 is W2, where W2 is ≥ 0 mm, ensuring that the end of the bent portion does not exceed the edge of the negative electrode active material 45.

[0089] This design prevents the negative electrode plate 40 from extending to the area of ​​the plate 60 corresponding to the negative active material 45, ensuring that the overall thickness of the battery does not increase after the plate 60 is assembled, and avoiding uneven thickness of the battery cell caused by the setting of the bent part.

[0090] As a further optimization, the portion of the electrode sheet 60 corresponding to the third blank area 63 is bent twice toward the side of the electrode sheet 60 not coated with the negative electrode active material 45. The horizontal distance between the end of the bent portion and the connection between the third blank area 63 and the negative electrode active material 45 is W3, where W3 ≥ 0 mm. This ensures that the trimmed edge is completely enclosed within the portion of the electrode sheet 60 corresponding to the third blank area 63. This design also avoids increasing the thickness of the battery cell and changing its thickness uniformity.

[0091] The tab-free battery cell 10 with this design can effectively reduce the cutting process of the electrode 60, solve the burr problem, optimize and delete the tab welding process, reduce the process difficulty, and improve the consistency and stability of the battery.

[0092] The positive electrode connection area 21 and the negative electrode connection area 22 are respectively provided with conductive glue connected to the positive electrode sheet 30 and the negative electrode sheet 40 to avoid poor contact between the positive electrode sheet 30 and the negative electrode sheet 40 and the positive electrode connection area 21 and the negative electrode connection area 22.

[0093] Combine Figure 2 and Figure 3 As shown, the connection between the positive electrode sheet 30 and the negative electrode sheet 40 and the shell 20 is respectively provided with a bending portion 70, so that the connection between the positive electrode sheet 30 and the negative electrode sheet 40 and the shell 20 is bent toward the direction of the shell 20. When the positive electrode sheet 30 and the negative electrode sheet 40 are pressed together, one side of the edge of the positive electrode sheet 30 and the negative electrode sheet 40 is in contact with the shell 20, and the other side is in contact with the positive electrode sheet 30 and the negative electrode sheet 40, thereby avoiding the phenomenon that the edge of the positive electrode sheet 30 and the negative electrode sheet 40 contacts the diaphragm 50, thereby avoiding the burrs on the edge of the positive electrode sheet 30 and the negative electrode sheet 40 from piercing the diaphragm 50, thereby preventing short circuit inside the battery cell.

[0094] Further optimization, such as Figure 4 As shown, the bending portion 70 is configured to have at least two bends, so that the edges of the positive electrode sheet 30 and the negative electrode sheet 40 are wrapped inside the bending portion 70. Under this design, the edges of the positive electrode sheet 30 and the negative electrode sheet 40 are prevented from contacting the shell 20 and the diaphragm 50, thereby preventing burrs from piercing the shell 20 or puncturing the diaphragm 50, thereby ensuring the service life of the battery cell.

[0095] Further optimized, the diaphragm 50 extends to the side of the positive electrode sheet 30 and the negative electrode sheet 40 corresponding to the shell 20, so that the diaphragm 50 separates the positive electrode sheet 30 and the negative electrode sheet 40 from the shell 20. Figure 2 、 Figure 3 and Figure 4As shown, the separator 50 separates the two adjacent first positive current collectors 32 and the first negative current collector 42. Furthermore, one end of the separator 50 extends horizontally and covers the side of the multiple positive current collector junctions 33 facing the housing 20. Similarly, the other end of the separator 50 extends horizontally and covers the side of the multiple negative current collector junctions 43 facing the housing 20. In this case, only the positive current collector extension region 34 and the negative current collector extension region 44 are connected to the housing 20. This design increases the resistance between the positive and negative electrode sheets 30, 40, and the housing 20, preventing electrical conduction and slow leakage. It also avoids the risk of direct exposure of the positive and negative electrode sheets 30, 40 when the housing 20 is damaged, thereby improving the reliability of the battery cell.

[0096] The structure of the tab-free battery cell 10 provided by the present invention simplifies the tab structure in traditional battery technology, eliminates the tab welding process, and saves the space occupied by the tab. It avoids leakage of electrolyte from the tab sealing position. It also reduces the cutting edge of the electrode 60, and effectively bends and wraps the required cutting edge, which greatly avoids the impact of cutting burrs on the performance of the battery cell, reduces the cutting process, improves production efficiency, and correspondingly increases the service life of the cutting equipment. It also greatly reduces the various precision requirements for battery cell production equipment. The overall structure of the tab-free battery cell 10 is greatly simplified, the appearance is more square, and the symmetry is extremely strong, which effectively promotes the unification and standardization of batteries.

[0097] Combine Figure 10 、 Figure 11 and Figure 12 As shown, the present invention further provides a battery module 80, comprising a plurality of the aforementioned tab-free battery cells 10, wherein the tab-free battery cells 10 include all the technical features of the aforementioned tab-free battery cells 10. A heat dissipation structure is provided inside the battery module 80 to ensure a long service life of the battery module 80.

[0098] The shell 20 is made of a photoconductive material, and a light-shielding film is provided on the outer periphery of the shell 20. The light-shielding film is configured to expose the positive connection area 21 and the negative connection area 22 to prevent the battery from being misoperated, that is, being mistakenly set in a light space, so as to prevent the shell 20 from becoming fully conductive and preventing the positive and negative electrodes from short-circuiting. A transparent conductive film 81 is provided between two adjacent shells 20 and between the shell 20 and the positive terminal 83 and the negative terminal 84 of the battery module 80, respectively. An incident light source 82 is provided on the transparent conductive film 81. When in use, the incident light source 82 emits irradiation light toward the transparent conductive film 81, and then disperses the light to the shells 20 on both sides thereof through the transparent conductive film 81, making the corresponding positive connection area 21 and the negative connection area 22 conductive. Further optimized, light-dispersing particles are doped in the transparent conductive film 81 to uniformly radiate light to the contact surface of the shell 20, thereby ensuring the consistency of the conductivity of the shell 20.

[0099] Among them, the transparent conductive film 81 contains at least one material selected from ITO (In2O3: Sn), FTO (Sn2O2: F), AZO (ZnO: Al), FZO, ATO, PTO, IFO, GZO, IZO, and ZnO. Preferably, the transparent conductive film 81 is made of ITO material. Specifically, the transparent conductive film 81 includes but is not limited to the above materials, and the transparent conductive film 81 can be made of a mixture of two or more materials. The physical shape structure of the light-dispersing particles is one or a combination of at least two of pits, free-form surface lenses, microlenses, gratings, and microprisms. The size is preferably between 100nm and 1mm, and the material is fused quartz, sapphire, or transparent gas. In addition, the light-dispersing particles can also be other materials and structural forms, as long as the effect of uniform light dispersion can be achieved.

[0100] When the battery module 80 needs to conduct electricity to the outside, the incident light source 82 is turned on. After the light penetrates the transparent conductive film 81, it is radiated onto the shell 20 of the tab-free battery cell 10, so that the corresponding positive connection area 21 and the negative connection area 22 are converted into a conductive state.

[0101] Since the shell 20 in contact with the positive electrode sheet 30 and the negative electrode sheet 40 in the tab-free battery cell 10 is conductive and the transparent conductive film 81 itself is conductive, the battery cells can be grouped.

[0102] Conductive glue is provided between the shell 20 and the transparent conductive film 81, and between the transparent conductive film 81 and the positive terminal 83 and the negative terminal 84 of the battery module 80. Preferably, the conductive glue is made of a transparent material, and at least the conductive glue between the shell 20 and the transparent conductive film 81 is made of a transparent material to ensure stable connection contact, good light radiation penetration and good conductivity.

[0103] The outer surface of the transparent conductive film 81 is provided with a light-shielding coating, which is configured to expose portions of the transparent conductive film 81 corresponding to the positive connection area 21, the negative connection area 22 and the incident light source 82, thereby preventing areas that should not be conductive from conducting electricity when light leakage occurs in the battery module 80.

[0104] The positive terminal 83 and the negative terminal 84 are each provided with an elastic component 85 for connecting to the outer shell of the battery module 80. During installation, the elastic component 85 applies pressure to compress the positive terminal 83 and the negative terminal 84 as well as the tab-free battery cell 10 and the transparent conductive film 81, so that all components of the entire battery assembly are in good contact.

[0105] like Figure 10As shown, a plurality of tab-free battery cells 10 are connected in series to form a battery module 80, a transparent conductive film 81 is provided between two adjacent tab-free battery cells 10, and an incident light source 82 is provided on the transparent conductive film 81. The number of tab-free battery cells 10 can be set according to the voltage of the battery module 80 required. Figure 11 As shown, multiple tab-free battery cells 10 are connected in parallel to form a battery module 80, and the same side of multiple tab-free battery cells 10 are connected through a transparent conductive film 81. The number of tab-free battery cells 10 can be set according to demand. Figure 12 As shown, a plurality of tab-free battery cells 10 are connected in series and in parallel to form a battery module 80, and a transparent conductive film 81 is provided between two adjacent tab-free battery cells 10 arranged in series; a plurality of tab-free battery cells 10 arranged in parallel are connected through the transparent conductive film 81. Specifically, a plurality of battery modules 80 are first connected in series and then in parallel. In other embodiments, the battery cells in the battery module are of a series-parallel integrated structure, the battery cells in each row are connected in series to form a battery cell group, and the battery cells in each column are connected in parallel to form a parallel group, and the transparent conductive film 81 is provided between any two columns, and is a whole sheet of transparent conductive film 81.

[0106] The assembly pack scheme of the battery module 80 provided by the present invention is greatly simplified, and the layout of the tab-free battery cells 10 is more neatly arranged and orderly, which is convenient for the development, design and maintenance of the battery module 80. The charging and discharging of the tab-free battery cells 10 and the battery module 80 can only be turned on by the incident light source 82. When a battery fails, the incident light source 82 can be quickly turned off to cut off the tab-free battery cells 10, so that the tab-free battery cells 10 are completely isolated and partitioned from each other, and cannot be electrically connected, so that fault handling can be quickly achieved. In addition, in the daily non-working state and in the case of fault power outage, the tab-free battery cells 10 are in a completely insulated state, which greatly improves the safety of the tab-free battery cells 10 and the battery module 80. In addition, the upper limit of the conductivity of the shell 20 can be changed by adjusting the intensity, frequency or beam area of ​​the incident light source 82, thereby limiting the maximum input power and output power of the battery cell to protect the battery cell and improve safety.

[0107] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0108] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments described herein, but is to be construed in the widest possible manner consistent with the principles and novel features disclosed herein.

Claims

1. A tab-free battery cell, characterized in that: The invention comprises a shell (20) and a battery cell body arranged inside the shell (20), wherein the shell (20) is provided with a positive electrode connection area (21) and a negative electrode connection area (22) capable of conducting electricity, wherein at least the portion of the shell (20) provided with the positive electrode connection area (21) and the negative electrode connection area (22) is made of a photoconductive material, and the battery cell body comprises a positive electrode sheet (30) and a negative electrode sheet (40) arranged opposite to each other, wherein the positive electrode sheet (30) and the negative electrode sheet (40) are separated by a diaphragm (50), the positive electrode sheet (30) is connected to the positive electrode connection area (21), and the negative electrode sheet (40) is connected to the negative electrode connection area (22).

2. The tab-free battery cell according to claim 1, wherein: A plurality of positive electrode material portions (31) are arranged at intervals on the positive electrode plate (30), and a plurality of negative electrode material portions (41) are arranged at intervals on the negative electrode plate (40). The plurality of positive electrode material portions (31) and the plurality of negative electrode material portions (41) are arranged alternately.

3. The tab-free battery cell according to claim 2, wherein: The positive electrode sheet (30) includes a plurality of first positive electrode current collectors (32) arranged at intervals and a positive electrode current collector junction area (33) for connecting two adjacent first positive electrode current collectors (32); a positive electrode current collector extension area (34) for connecting to the positive electrode connection area (21) is connected to the positive electrode current collector junction area (33) at the edge; positive electrode active materials (35) are provided on both sides of the first positive electrode current collector (32); the first positive electrode current collector (32) and the positive electrode active materials (35) constitute the positive electrode material portion (31); The negative electrode sheet (40) includes a plurality of first negative electrode current collectors (42) arranged at intervals and a negative electrode current collector junction area (43) for connecting two adjacent first negative electrode current collectors (42). The negative electrode current collector junction area (43) at the edge is connected to a negative electrode current collector extension area (44) for connecting to the negative electrode connection area (22). Negative electrode active materials (45) are provided on both sides of the first negative electrode current collector (42). The first negative electrode current collector (42) and the negative electrode active materials (45) constitute the negative electrode material portion (41).

4. The tab-free battery cell according to claim 3, wherein: The first positive electrode current collector (32) includes two positive electrode current collector bodies (321), each of the positive electrode current collector bodies (321) having a first end and a second end opposite to each other, the first ends of the two positive electrode current collector bodies (321) being connected to each other, and the second ends of the two positive electrode current collector bodies (321) being connected to the positive electrode current collector junction area (33) adjacent to each other.

5. The tab-free battery cell according to claim 4, characterized in that: The positive electrode plate (30) is formed by bending a plate (60) coated with the positive electrode active material (35) on one side, and the positive electrode active material (35) is arranged at intervals along the length direction of the plate (60) so that a first blank area (61) is formed between two adjacent positive electrode active materials (35). A second blank area (62) is provided on the plate (60) at one end. The portion of the plate (60) coated with the positive electrode active material (35) is bent to form the positive electrode material portion (31), the portion of the plate (60) corresponding to the first blank area (61) forms the positive electrode current collector junction area (33), and the portion of the plate (60) corresponding to the second blank area (62) is bent to form the positive electrode current collector extension area (34).

6. The tab-free battery cell according to claim 5, characterized in that: A portion of the current collector corresponding to the positive electrode active material (35) is bent to form the positive electrode current collector body (321), and the first ends of two adjacent positive electrode current collector bodies (321) are connected via the first blank area (61).

7. The tab-free battery cell according to claim 5, characterized in that: The distance of the first blank area (61) along the length direction of the pole piece (60) is L1, L1=2(A+B+C+D+X); Wherein, A is the thickness of the negative electrode active material (45), B is the thickness of the separator (50), C is the thickness of the positive electrode active material (35), D is the thickness of the first negative electrode current collector (42), and X is the 90° sheet metal unfolding length of the first positive electrode current collector (32).

8. The tab-free battery cell according to claim 7, characterized in that: The distance of the first blank area (61) along the length direction of the pole piece (60) is less than 5 mm.

9. The tab-free battery cell according to claim 5, characterized in that: The width of the positive electrode active material (35) is smaller than the width of the first positive electrode current collector (32), so that a third blank area (63) is formed on both sides of the pole piece (60), and the portion of the pole piece (60) corresponding to the third blank area (63) is bent toward the side of the pole piece (60) not coated with the positive electrode active material (35).

10. The tab-free battery cell according to claim 9, characterized in that: The dimension of the third blank area (63) after bending in the width direction of the electrode (60) is W1, wherein W1≤10mm; the horizontal distance between the end of the bent portion of the third blank area (63) and the connection between the third blank area (63) and the positive electrode active material (35) is W2, wherein W2≥0mm.

11. The tab-free battery cell according to claim 9, characterized in that: The portion of the electrode (60) corresponding to the third blank area (63) is bent twice toward the side of the electrode (60) not coated with the positive electrode active material (35), and the horizontal distance between the end of the bent portion and the connection between the third blank area (63) and the positive electrode active material (35) is W3, where W3 ≥ 0 mm.

12. The tab-free battery cell according to claim 3, characterized in that: The first negative electrode current collector (42) includes two negative electrode current collector bodies (421), each of the negative electrode current collector bodies (421) having a first end and a second end opposite to each other, the first ends of the two negative electrode current collector bodies (421) being connected to each other, and the second ends of the two negative electrode current collector bodies (421) being connected to the adjacent negative electrode current collector junction area (43) respectively.

13. The tab-free battery cell according to claim 12, characterized in that: The negative electrode plate (40) is formed by bending a plate (60) coated with the negative electrode active material (45) on one side, and the negative electrode active material (45) is arranged at intervals along the length direction of the plate (60) so that a first blank area (61) is formed between two adjacent negative electrode active materials (45). A second blank area (62) is provided on the plate (60) at one end. The portion of the plate (60) coated with the negative electrode active material (45) is bent to form the negative electrode material portion (41), the portion of the plate (60) corresponding to the first blank area (61) forms the negative electrode current collector junction area (43), and the portion of the plate (60) corresponding to the second blank area (62) is bent to form the negative electrode current collector extension area (44).

14. The tab-free battery cell according to claim 13, characterized in that: A portion of the current collector corresponding to the negative electrode active material (45) is bent to form the negative electrode current collector body (421), and the first ends of two adjacent negative electrode current collector bodies (421) are connected via the first blank area (61).

15. The tab-free battery cell according to claim 13, characterized in that: The distance of the first blank area (61) along the length direction of the pole piece (60) is L2, L2=2(A+B+C+E+Y); Wherein, A is the thickness of the negative electrode active material (45), B is the thickness of the separator (50), C is the thickness of the positive electrode active material (35), E is the thickness of the first positive electrode collector (32), and Y is the 90° sheet metal unfolding length of the first negative electrode collector (42).

16. The tab-less battery cell according to claim 15, characterized in that: The distance of the first blank area (61) along the length direction of the pole piece (60) is less than 5 mm.

17. The tab-less battery cell according to claim 13, characterized in that: The width of the negative electrode active material (45) is smaller than the width of the first negative electrode current collector (42), so that a third blank area (63) is formed on both sides of the electrode piece (60), and the portion of the electrode piece (60) corresponding to the third blank area (63) is bent toward the side of the electrode piece (60) not coated with the negative electrode active material (45).

18. The tab-less battery cell according to claim 17, characterized in that: The dimension of the third blank area (63) after bending in the width direction of the electrode (60) is W1, wherein W1≤10mm; the horizontal distance between the end of the bent portion of the third blank area (63) and the connection between the third blank area (63) and the negative electrode active material (45) is W2, wherein W2≥0mm.

19. The tab-less battery cell according to claim 17, characterized in that: The portion of the electrode (60) corresponding to the third blank area (63) is bent twice toward the side of the electrode (60) not coated with the negative electrode active material (45), and the horizontal distance between the end of the bent portion and the connection between the third blank area (63) and the negative electrode active material (45) is W3, where W3 ≥ 0 mm.

20. The tab-free battery cell according to any one of claims 1 to 19, characterized in that: The positive electrode connection region (21) and the negative electrode connection region (22) are respectively provided with conductive glue connected to the positive electrode plate (30) and the negative electrode plate (40).

21. The tab-free battery cell according to any one of claims 1 to 19, characterized in that: The connection points between the positive electrode sheet (30) and the negative electrode sheet (40) and the shell (20) are respectively provided with bending portions (70).

22. The tab-free battery cell according to claim 21, characterized in that: The bending portion (70) is configured as two bends, such that the edges of the positive electrode sheet (30) and the negative electrode sheet (40) are wrapped inside the bending portion (70).

23. The tab-free battery cell according to any one of claims 1 to 19, characterized in that: The diaphragm (50) extends to a side of the positive electrode sheet (30) and the negative electrode sheet (40) corresponding to the housing (20).

24. The tab-less battery cell according to any one of claims 1 to 19, characterized in that: A light-shielding film is provided on the outer periphery of the housing (20), and the light-shielding film is configured to allow the positive electrode connection area (21) and the negative electrode connection area (22) to be exposed.

25. A battery module, characterized in that: Comprising a plurality of tab-free battery cells (10) as described in any one of claims 1 to 24.

26. The battery module according to claim 25, characterized in that A transparent conductive film (81) is provided between two adjacent shells (20) and between the shell (20) and the positive terminal (83) and the negative terminal (84) of the battery module (80), respectively. An incident light source (82) is provided on the transparent conductive film (81).

27. The battery module according to claim 26, characterized in that: Light dispersing particles are doped in the transparent conductive film (81).

28. The battery module according to claim 26, characterized in that Conductive glue is provided between the housing (20) and the transparent conductive film (81), and between the transparent conductive film (81) and the positive terminal (83) and the negative terminal (84) of the battery module (80).

29. The battery module according to claim 28, characterized in that The conductive glue between the housing (20) and the transparent conductive film (81) is made of a transparent material.

30. The battery module according to claim 26, wherein: The outer surface of the transparent conductive film (81) is provided with a light-shielding coating, and the light-shielding coating is configured to expose portions of the transparent conductive film (81) corresponding to the positive electrode connection region (21), the negative electrode connection region (22), and the incident light source (82).

31. The battery module according to claim 26, characterized in that The positive terminal (83) and the negative terminal (84) are respectively provided with elastic components (85) for connecting to the outer shell of the battery module (80).

32. The battery module according to claim 26, wherein: A plurality of the tab-free battery cells (10) are connected in series to form the battery module (80), and the transparent conductive film (81) is provided between two adjacent tab-free battery cells (10); or A plurality of the tab-free battery cells (10) are connected in parallel to form the battery module (80), and the same sides of the plurality of tab-free battery cells (10) are connected via the transparent conductive film (81); or A plurality of the tab-free battery cells (10) are connected in series and in parallel to form the battery module (80), and a transparent conductive film (81) is provided between two adjacent tab-free battery cells (10) arranged in series; and a plurality of the tab-free battery cells (10) arranged in parallel are connected via the transparent conductive film (81).

33. The battery module according to any one of claims 25 to 32, characterized in that: A heat dissipation structure for dissipating heat is provided inside the battery module (80).

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