Battery cell assembly, lithium battery and assembly method of battery cell assembly of lithium battery

Abstract

The invention provides a battery cell assembly, a lithium battery and an assembly method of the battery cell assembly of the lithium battery, and a battery cell unit, the battery cell assembly comprises a plurality of battery cells, positive tabs and negative tabs are arranged at intervals along the width direction of the battery cells, and the positive tabs and the negative tabs are folded to one side of a battery cell body along the thickness direction of the battery cells; each of the positive electricity connecting piece and the negative electricity connecting piece is provided with a drainage area and a bending area, the positive tabs of a part of the battery cells in the plurality of battery cells are independently arranged and are electrically connected with the drainage area of the positive electricity connecting piece, and the positive tabs of the remaining battery cells in the plurality of battery cells are independently arranged and are electrically connected with the bending area of the positive electricity connecting piece; the negative tabs of a part of the battery cells are independently arranged and are electrically connected with the drainage area of the negative electricity connecting piece, and the negative tabs of the remaining battery cells are independently arranged and are electrically connected with the bending area, so that the plurality of battery cells are arranged in parallel. According to the technical scheme, the problems of tearing, insufficient soldering and low energy density caused by too thick battery cell assembly tabs in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of battery assembly technology, and more specifically, to a cell assembly, a lithium battery, and a method for assembling the cell assembly of a lithium battery. Background Technology

[0002] Currently, in order to pursue higher single-cell capacity, lithium batteries often adopt a multi-cell parallel process route inside a single battery: First, two single cells are paired, and then the corresponding positive and negative tabs of the two cells are joined together and ultrasonically welded together to obtain paired dual cells. Then, the corresponding positive and negative tabs of the two sets of paired dual cells are ultrasonically welded together with the positive and negative connecting pieces, respectively. Finally, the connecting pieces are welded to the cover plate. After the two sets of paired dual cells are combined, bundled, covered with insulating film, inserted into the shell, and the cover plate is laser welded to the shell opening, the parallel assembly of four cells is completed.

[0003] However, this process has a drawback: after pairing two single cells, the number of layers of tabs increases, resulting in a larger overall thickness of the tabs. This makes it prone to tearing of the outer tabs and poor soldering of the inner tabs during ultrasonic welding with the positive / negative electrode connectors. To address these shortcomings of the existing assembly process, this invention proposes an assembly method for a cell assembly, a lithium battery, and a lithium battery cell assembly to solve the problems of tearing of the outer tabs and poor soldering of the inner tabs in parallel cell connections. Summary of the Invention

[0004] The main objective of this invention is to provide a cell assembly, a lithium battery, and a method for assembling a cell assembly of a lithium battery, in order to solve the problems of tab tearing and poor soldering in the prior art.

[0005] To achieve the above objectives, the present invention provides a battery cell assembly, comprising: a battery cell unit including multiple battery cells, each battery cell including a battery cell body, a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab being spaced apart along the width direction of the battery cell, and both the positive electrode tab and the negative electrode tab being converged to one side of the battery cell body along the thickness direction of the battery cell; a positive electrical connector and a negative electrical connector, each having a current-draining area and a bending area, wherein the positive electrode tabs of a portion of the multiple battery cells are independently arranged and electrically connected to the current-draining area of ​​the positive electrical connector, the positive electrode tabs of the remaining multiple battery cells are independently arranged and electrically connected to the bending area of ​​the positive electrical connector, the negative electrode tabs of a portion of the battery cells are independently arranged and electrically connected to the current-draining area of ​​the negative electrical connector, and the negative electrode tabs of the remaining battery cells are independently arranged and electrically connected to the bending area, so that the multiple battery cells are arranged in parallel.

[0006] In the above technical solution, the positive and negative tabs are spaced apart and gathered to one side. Electrical connections are established by independently welding the positive tabs of a portion of the multiple battery cells to the current-guiding area of ​​the positive connector, and independently welding the negative tabs of the same portion to the current-guiding area of ​​the negative connector. The remaining battery cells have their positive tabs independently welded to the bending area of ​​the positive connector, and their negative tabs independently welded to the bending area of ​​the negative connector. This facilitates the stacking of the battery cells while eliminating the need for the tabs to be joined together, allowing multiple battery cells to be connected in parallel. This avoids increasing the number of tab layers and the overall thickness of the tabs, effectively preventing the problems of tearing of the outer tabs and poor soldering of the inner tabs that are common in traditional parallel connection methods. Therefore, the battery cell assembly of this invention can achieve parallel connection of multiple battery cells without increasing the tab length and welding thickness, greatly reducing the risk of tab tearing and poor soldering during ultrasonic welding, and effectively reducing structural risks.

[0007] Furthermore, multiple battery cells are arranged sequentially along the thickness direction of the battery cells. In the length direction of the battery cells, the battery cell body has a first side and a second side arranged opposite to each other. The positive and negative tabs of a portion of the battery cells are located on the first side, and the positive and negative tabs of the remaining battery cells are located on the second side. Along the length direction, the current-draining area and the bending area are located on both sides of the battery cell unit. Multiple positive tabs located on the first side are independently arranged and are all electrically connected to the current-draining area of ​​the positive electrical connector. Multiple negative tabs located on the first side are independently arranged and are all electrically connected to the current-draining area of ​​the negative electrical connector. Multiple positive tabs located on the second side are independently arranged and are all electrically connected to the bending area of ​​the positive electrical connector. Multiple negative tabs located on the second side are independently arranged and are all electrically connected to the bending area of ​​the negative electrical connector.

[0008] In the above technical solution, by dividing the positive tabs of multiple battery cells into two parts, one part is electrically connected to the current-guiding area of ​​the positive electrical connector, and the other part is electrically connected to the bending area of ​​the positive electrical connector. Similarly, by dividing the negative tabs of multiple battery cells into two parts, one part of the negative tabs of the battery cells is electrically connected to the current-guiding area of ​​the negative electrical connector, and the other part of the negative tabs of the battery cells is electrically connected to the bending area of ​​the negative electrical connector, different battery cells can be connected in parallel through electrical connectors. In this way, it is not necessary to directly connect the tabs of multiple battery cells to each other, thus effectively avoiding the welding and fixing between the tabs, and thus effectively avoiding the problems of excessively thick or poorly welded tabs.

[0009] Furthermore, the width of the drainage area is greater than the width of the bending area, and the number of battery cells is four; the positive and negative tabs of the two middle battery cells are located on the second side, and the positive and negative tabs of the two side battery cells are located on the first side; the two positive tabs on the second side are arranged opposite to each other in the thickness direction, the two negative tabs on the second side are arranged opposite to each other in the thickness direction, the two positive tabs on the first side are arranged opposite to each other in the thickness direction, and the two negative tabs on the first side are arranged opposite to each other in the thickness direction.

[0010] In the above technical solution, the purpose of having a wider drainage area than a wider bending area is to facilitate the connection of the two positive tabs opposite to the first side, while the two positive tabs opposite to the second side are easily bent into the bending area. This allows the tabs to be bent and connected without excessive bending during the stacking and parallel connection of multiple cells, effectively reducing the required length of the tabs and preventing S-shaped bending that could cause the tabs to be inserted into the cell, thus effectively improving the stability and safety performance of the cell. It should be noted that the width of the drainage area or bending area described in this application refers to the width formed in the thickness direction of the cell unit.

[0011] Furthermore, the outer periphery of the first and second cells of the four-cell assembly is provided with multiple binding straps, as are the outer periphery of the third and fourth cells; all four cells are provided with multiple binding straps. In this way, the binding straps are used to secure the multiple cells that have been assembled and joined together, ensuring that the cells do not deflect or shift during assembly, thereby improving the overall stability of the assembly process.

[0012] Furthermore, the two middle cells of the four battery cells are equipped with multiple binding straps around their outer periphery; all four battery cells are equipped with multiple binding straps around their outer periphery. In this way, after ensuring the stability of the two middle cells during assembly, the four battery cells are then bound and secured to further ensure that the battery cells will not deflect or shift during assembly.

[0013] Furthermore, the width of the bending area is greater than the width of the drainage area, and the number of battery cells is four; the positive and negative tabs of the two middle battery cells are located on the first side, and the positive and negative tabs of the two side battery cells are located on the second side; the two positive tabs on the second side are arranged opposite to each other in the thickness direction, the two negative tabs on the second side are arranged opposite to each other in the thickness direction, the two positive tabs on the first side are arranged opposite to each other in the thickness direction, and the two negative tabs on the first side are arranged opposite to each other in the thickness direction.

[0014] In the above technical solution, by setting the width of the bending area to be greater than the width of the drainage area, the two positive electrodes and the two negative electrodes set opposite each other on the second side can be easily electrically connected to the bending area in the thickness direction, so as to ensure the stability of the electrical connection.

[0015] Furthermore, the four battery cells are secured with multiple binding straps. This enhances the stability of the battery cell assembly during assembly.

[0016] Furthermore, both the positive and negative electrical connectors include a draining section, a connecting section, and a bending section connected in sequence. The draining section and the connecting section are arranged at an angle, and the bending section and the connecting section are arranged at an angle. Along the thickness direction of the connecting section, the draining section and the bending section are located on the same side of the connecting section. The draining section forms a draining area, and the bending section forms a bending area.

[0017] In the above technical solution, by setting the angles between the connecting section and the current-draining section and the bending section respectively, the positive and negative electrical connectors are adapted to the shape of the battery cell. After assembly, the length direction of the positive and negative electrical connectors fits with the side of the battery cell, effectively adapting to the assembly shape of the battery cell. This effectively reduces the overall volume of the assembled battery cell assembly and makes the overall shape of the battery cell assembly regular, which facilitates the subsequent stacking of the battery cell assemblies and can effectively improve the energy density of the battery cell assembly.

[0018] Furthermore, a stress-relieving section connects the connecting section and the bending section. This stress-relieving section is bent, and multiple bending stress holes are provided along the bending line, spaced apart. In this way, during cell assembly, when the bending section is bent, the stress generated during bending is relieved and dissipated by the stress-relieving section and the bending stress holes, preventing irregular protrusions or breaks at the bending location.

[0019] Furthermore, the drainage section, connecting section, and bending section are integrally molded. This strengthens the overall strength of both the positive and negative electrical connectors, making the bending section less prone to breakage during bending.

[0020] Furthermore, the connecting section and bending section are integrally formed, while the current-draining section and connecting section are separate and welded together. This allows for the assembly of the battery cell without the connecting section, followed by welding and fixing the connecting section. This provides more assembly methods to adapt to different assembly environments, thus facilitating the battery cell assembly operation.

[0021] Furthermore, the lead-in section is provided with a first step groove, which is located on the side of the lead-in section away from the cell unit to form a first step; the connecting section is provided with a second step groove, which is located on the side of the connecting section facing the cell unit to form a second step, and the first step and the second step are fastened and welded together.

[0022] In the above technical solution, by setting the first step and the second step, the two sets of step grooves can be directly aligned when connecting the connecting section and the diversion section. Then, welding can be carried out directly according to the position of the step groove, avoiding the problem of welding position deviation or misalignment between the diversion section and the connecting section. This effectively improves the cell assembly efficiency while ensuring structural strength.

[0023] Furthermore, there are four battery cells, which are divided into two battery cell groups. Each battery cell group includes two battery cells stacked along the thickness direction. Along the length direction of the battery cells, the two battery cell groups are arranged along the length direction. Along the length direction, the current-draining area and the bending area are located on both sides of the first battery cell group. The positive tabs of the first battery cell group are all electrically connected to the current-draining area of ​​the positive electrical connector, and the negative tabs of the first battery cell group are all electrically connected to the current-draining area of ​​the negative electrical connector. The positive tabs of the second battery cell group are all electrically connected to the bending area of ​​the positive electrical connector, and the negative tabs of the second battery cell group are all electrically connected to the bending area of ​​the negative electrical connector.

[0024] In this way, a completely different four-cell parallel structure can be provided to adapt to different assembly processes and further expand the final assembly form, so that the cell assembly can be adapted to external limiting structures of different shapes or forms.

[0025] According to another aspect of the present invention, the present invention provides a lithium battery, including a cover plate, a housing, and the aforementioned cell assembly, wherein the cell assembly is disposed inside the housing, the cover plate is disposed on the housing, the positive terminal of the cover plate is electrically connected to the current-draining area of ​​the positive terminal, and the negative terminal of the negative terminal is electrically connected to the negative terminal of the cover plate.

[0026] Furthermore, the outer casing is a cylindrical structure with openings at both ends. The lithium battery includes two cell assemblies and two cover plates. The two cover plates are respectively placed on both ends of the outer casing. The two cell assemblies are arranged back to back inside the outer casing, and the two cell assemblies are insulated from each other by an insulating film.

[0027] In the above technical solution, after the assembly of the battery cell assembly is completed, an insulating film is wrapped on the outer surface of the battery cell assembly to prevent the battery cell from being scratched during the subsequent battery cell insertion process; two battery cell assemblies are respectively inserted into a shell with openings at both ends, and finally the substrates corresponding to the two sets of cover plates are welded to the two side ports of the shell by laser. Due to the reduction in the number of tab layers, the gap between the tabs and the cover plates is reduced, and the bottom restriction in the traditional shell is eliminated between the two four-cell parallel structures, thus improving the energy density of the entire lithium battery.

[0028] According to another aspect of the present invention, the present invention provides a method for assembling a lithium battery cell assembly, the method for assembling the lithium battery cell assembly described above.

[0029] Furthermore, the assembly method of the lithium battery cell assembly includes: along the thickness direction of the cell, gathering both the positive and negative tabs to one side of the cell body; independently setting the positive tabs of a portion of the multiple cells and electrically connecting them to the current-guiding area of ​​the positive connector; independently setting the positive tabs of the remaining cells and electrically connecting them to the bending area of ​​the positive connector; independently setting the negative tabs of a portion of the cells and electrically connecting them to the current-guiding area of ​​the negative connector; and independently setting the negative tabs of the remaining cells and electrically connecting them to the bending area, so that the multiple cells are arranged in parallel.

[0030] In the above technical solution, the positive and negative tabs are spaced apart and gathered to one side. Electrical connections are established by independently welding the positive tabs of a portion of the multiple battery cells to the current-guiding area of ​​the positive connector, and independently welding the negative tabs of the same portion to the current-guiding area of ​​the negative connector. The remaining battery cells have their positive tabs independently welded to the bending area of ​​the positive connector, and their negative tabs independently welded to the bending area of ​​the negative connector. This facilitates the stacking of the battery cells while eliminating the need for the tabs to be joined together, allowing multiple battery cells to be connected in parallel. This avoids increasing the number of tab layers and the overall thickness of the tabs, effectively preventing the problems of tearing of the outer tabs and poor soldering of the inner tabs that are common in traditional parallel connection methods. Therefore, the battery cell assembly of this invention can achieve parallel connection of multiple battery cells without increasing the tab length and welding thickness, greatly reducing the risk of tab tearing and poor soldering during ultrasonic welding, and effectively reducing structural risks.

[0031] By applying the technical solution of this invention, an electrical connection is established by setting the positive and negative tabs alternately and gathering them to one side, and by independently welding the positive tabs of a portion of the multiple battery cells to the current-guiding area of ​​the positive electrical connector, and independently welding the negative tabs of the aforementioned portion of the battery cells to the current-guiding area of ​​the negative electrical connector; and independently welding the positive tabs of the remaining multiple battery cells to the bending area of ​​the positive electrical connector, and independently welding the negative tabs of the remaining battery cells to the bending area of ​​the negative electrical connector. This facilitates the stacking of the battery cells and allows multiple battery cells to be connected in parallel without the need to close the tabs between them. This avoids increasing the number of tab layers and the overall thickness of the tabs, thereby effectively preventing the problems of tearing of the outer tabs and poor soldering of the inner tabs caused by the multi-layer closing and welding operations required in traditional parallel connection methods. Therefore, the battery cell assembly of this invention can achieve parallel connection of multiple battery cells without increasing the tab length and welding thickness, greatly reducing the risk of tab tearing and poor soldering during ultrasonic welding, and effectively reducing structural risks. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the battery cell unit and its tabs after they have been folded up according to the present invention;

[0034] Figure 2(a) is a schematic diagram of the pairing of dual battery cells in Embodiment 1 of the present invention;

[0035] Figure 2(b) is a front view of the paired dual-cell battery in Embodiment 1 of the present invention;

[0036] Figure 3(a) is a front view of the cover plate in Embodiment 1 of the present invention;

[0037] Figure 3(b) is a schematic diagram of the back of the cover plate in Embodiment 1 of the present invention;

[0038] Figure 4 This is a schematic diagram of the battery cell assembly process in Embodiment 1 of the present invention;

[0039] Figure 5 yes Figure 4 A cross-sectional view of the lithium battery AA in the image;

[0040] Figure 6 This is a schematic diagram of the battery cell assembly process in Embodiment 2 of the present invention;

[0041] Figure 7 This is a schematic diagram of the battery cell assembly process in Embodiment 3 of the present invention;

[0042] Figure 8 This is a schematic diagram of the welding structure of the drainage section and the cover plate in Embodiment 4 of the present invention;

[0043] Figure 9 This is a schematic diagram of the connecting section and the bending section in Embodiment 4 of the present invention;

[0044] Figure 10 This is a schematic diagram of the battery cell assembly process in Embodiment 4 of the present invention;

[0045] Figure 11 This is a schematic diagram of the battery cell assembly process in Embodiment 5 of the present invention;

[0046] Figure 12 This is a schematic diagram of the battery cell assembly process in Embodiment Six of the present invention;

[0047] Figure 13 This is a schematic diagram of the battery cell assembly process in Embodiment 7 of the present invention;

[0048] Figure 14 This is a schematic diagram of the battery cell assembly process in Embodiment 8 of the present invention.

[0049] The above figures include the following reference numerals:

[0050] 10. Battery cell; 101. Battery cell body; 102. Positive tab; 103. Negative tab; 104. Binding strap; 20. Cover plate; 201. Substrate; 202. Insulating gasket; 203. Positive terminal; 204. Negative terminal; 205. Positive connector; 208. Negative connector; 2011. Explosion-proof valve; 2012. Injection hole; 2051. Drainage section; 2052. Connecting section; 2053. Bending section; 2054. Bending stress hole; 30. Insulating film; 40. Outer shell. Detailed Implementation

[0051] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0052] Example 1

[0053] In existing technologies, after two single cells are paired, the number of layers and the overall thickness of the tabs increase after they are joined together. During the ultrasonic welding process between the tabs and the positive / negative electrode connecting pieces, the high-frequency vibration energy of the ultrasonic waves cannot be evenly distributed to all interfaces, causing stress concentration on the outer tabs. This eventually leads to tearing due to excessive fatigue and stretching. Meanwhile, the inner tabs, due to energy attenuation, cannot generate sufficient heat to achieve interlayer bonding, resulting in a weak solder joint. Therefore, as... Figures 1 to 5 As shown, Embodiment 1 of the present invention discloses a battery cell assembly, comprising: a battery cell unit including multiple battery cells, each battery cell including a battery cell body 101, a positive electrode tab 102 and a negative electrode tab 103, the positive electrode tab 102 and the negative electrode tab 103 being spaced apart along the width direction of the battery cell, and along the thickness direction of the battery cell, both the positive electrode tab 102 and the negative electrode tab 103 being converged to one side of the battery cell body 101; a positive electrical connector 205 and a negative electrical connector 208, each having a current-draining area and a bending area. The positive tabs 102 of a portion of the multiple battery cells are independently configured and electrically connected to the current-draining area of ​​the positive connector 205. The positive tabs 102 of the remaining multiple battery cells are independently configured and electrically connected to the bending area of ​​the positive connector 205. The negative tabs 103 of the aforementioned portion of the battery cells are independently configured and electrically connected to the current-draining area of ​​the negative connector 208. The negative tabs 103 of the remaining battery cells are independently configured and electrically connected to the bending area, so that the multiple battery cells are connected in parallel.

[0054] In the above technical solution, by spacing the positive tab 102 and negative tab 103 and bringing them together to one side, and by independently welding the positive tab 102 of a portion of the multiple battery cells to the current-guiding area of ​​the positive connector 205, and independently welding the negative tab 103 of the aforementioned portion of the battery cells to the current-guiding area of ​​the negative connector 208; and by independently welding the positive tab 102 of the remaining multiple battery cells to the bending area of ​​the positive connector 205, and independently welding the negative tab 103 of the remaining battery cells to the bending area of ​​the negative connector 208, an electrical connection is established, facilitating the connection of each battery cell 102. While stacking the cells, the tabs between each cell 10 do not need to be joined together, allowing multiple cells 10 to be connected in parallel. This avoids increasing the number of tab layers and the overall thickness of the tabs, thus effectively preventing the problems of outer tab tearing and inner tab cold solder joints that are easily caused by the multi-layer joining and welding operations required in traditional parallel connection methods. Therefore, the cell assembly of the present invention can be stacked and connected in parallel without increasing the tab length and welding thickness, greatly reducing the risk of tab tearing and cold solder joints during ultrasonic welding, and effectively reducing structural risks.

[0055] It should be noted that the positive tab 102 of some of the battery cells and the negative tab 103 of some of the battery cells belong to the same group of battery cells; similarly, the positive tab 102 and the negative tab 103 of the remaining battery cells belong to the same group of battery cells.

[0056] Specifically, see Figure 1 The positive tab 102 and negative tab 103 are located on the same side of the length direction (X direction) and at both ends of the width direction (Y direction) of the battery cell 10, respectively. The positive tab 102 and negative tab 103 are each composed of several independent layers of aluminum foil and copper foil stacked together. The positive tab 102 and negative tab 103 of the battery cell 10 are gathered together and brought to one side along the thickness direction (Z direction) of the battery cell 10, preferably by ultrasonic welding.

[0057] It should be noted that the battery cell 10 of the present invention can be a wound core, a stacked core, or a coiled core.

[0058] See Figure 2(a) to Figure 4In Embodiment 1 of the present invention, multiple battery cells are arranged sequentially along the thickness direction of the battery cells. In the length direction of the battery cells, the battery cell body 101 has a first side and a second side arranged opposite to each other. The positive tabs 102 and negative tabs 103 of a portion of the battery cells are located on the first side, and the positive tabs 102 and negative tabs 103 of the remaining battery cells are located on the second side. Along the length direction, the current-draining area and the bending area are located on both sides of the battery cell unit. The multiple positive tabs 102 located on the first side are independently arranged and are all electrically connected to the current-draining area of ​​the positive electrical connector 205. The multiple negative tabs 103 located on the first side are independently arranged and are all electrically connected to the current-draining area of ​​the negative electrical connector 208. The multiple positive tabs 102 located on the second side are independently arranged and are all electrically connected to the bending area of ​​the positive electrical connector 205. The multiple negative tabs 103 located on the second side are independently arranged and are all electrically connected to the bending area of ​​the negative electrical connector 208.

[0059] In the above technical solution, by dividing the positive tabs 102 of multiple battery cells into two parts, one part is electrically connected to the current-draining area of ​​the positive electrical connector 205, and the other part is electrically connected to the bending area of ​​the positive electrical connector 205. Similarly, by dividing the negative tabs 103 of multiple battery cells into two parts, one part of the negative tabs 103 of the battery cells is electrically connected to the current-draining area of ​​the negative electrical connector 208, and the other part of the negative tabs 103 of the battery cells is electrically connected to the bending area of ​​the negative electrical connector 208, different battery cells can be connected in parallel through electrical connectors. In this way, it is not necessary to directly connect the tabs of multiple battery cells to each other, thus effectively avoiding the welding and fixing between the tabs, and thus effectively avoiding the problems of excessively thick or poorly welded tabs.

[0060] Specifically, the two battery cells 10 shown in Figures 2(a) and 2(b) are stacked along the thickness direction (Z direction) of the battery cell 10. At this time, the positive electrode tabs 102 and negative electrode tabs 103 of the two battery cells 10 are respectively gathered to the lower side along their thickness direction. At this time, the positive electrode tabs 102 of the two battery cells 10 are all located on the same side along their width direction (Y direction), and the negative electrode tabs 103 are all located on the other side along their width direction (Y direction).

[0061] Secondly, referring to Figures 3(a) and 3(b), in this first embodiment, the positive terminal connector 205 and the negative terminal connector 208 are mainly composed of pins, which are divided into positive pins and negative pins. The pins are metal sheet structures, wherein the positive pins are made of aluminum and the negative pins are made of copper.

[0062] In existing technologies, to achieve the joining operation of two sets of paired dual-cell batteries, relatively long tabs are required. After joining, the multi-layered tabs exhibit an "S"-shaped bend, making it easy for the tabs to insert into the battery cell, thus posing a short-circuit risk. Therefore, see [link to relevant documentation]. Figure 4In Embodiment 1 of the present invention, the width of the drainage area is greater than the width of the bending area, and the number of battery cells is four. Specifically, the positive tabs 102 and negative tabs 103 of the two middle battery cells are located on the second side, and the positive tabs 102 and negative tabs 103 of the two side battery cells are located on the first side; the two positive tabs 102 on the second side are arranged opposite to each other in the thickness direction, the two negative tabs 103 on the second side are arranged opposite to each other in the thickness direction, the two positive tabs 102 on the first side are arranged opposite to each other in the thickness direction, and the two negative tabs 103 on the first side are arranged opposite to each other in the thickness direction.

[0063] In the above technical solution, the purpose of having a wider drainage area than a wider bending area is to facilitate the connection of two positive tabs (or two negative tabs) opposite to the first side. The two positive tabs (or two negative tabs) opposite to the second side are then easily bent into the bending area. This allows the tabs to be bent without requiring a long length during the stacking and parallel connection of multiple cells, and avoids excessive bending. This effectively reduces the required length of the tabs and prevents S-shaped bending from causing the tabs to insert into the cell, thus effectively improving cell stability and safety. It should be noted that the width of the drainage area or bending area described in this application refers to the width formed in the thickness direction of the cell unit.

[0064] See Figure 4 The first and second cells of the four battery cells are equipped with multiple binding straps 104 around their outer periphery, as are the third and fourth cells. Therefore, the binding straps 104 are used to secure the multiple cells that have been joined together, ensuring that no cell deflection or displacement occurs during assembly, thereby improving the overall stability of the assembly process.

[0065] Specifically, see Figures 2(a) to 2(b). Figure 4 The binding strap 104 is preferably made of insulating tape.

[0066] Referring to Figures 3(a) and 3(b), both the positive electrical connector 205 and the negative electrical connector 208 include a draining section 2051, a connecting section 2052 and a bending section 2053 connected in sequence. The draining section 2051 is set at an angle to the connecting section 2052, and the bending section 2053 is set at an angle to the connecting section 2052. Along the thickness direction of the connecting section 2052, the draining section 2051 and the bending section 2053 are located on the same side of the connecting section 2052. The draining section 2051 forms a draining area, and the bending section 2053 forms a bending area.

[0067] In the above technical solution, by setting the angles between the connecting section 2052 and the drain section 2051 and the bending section 2053 respectively, the positive electrical connector 205 and the negative electrical connector 208 are adapted to the shape of the battery cell. After assembly, the length direction of the positive electrical connector 205 and the negative electrical connector 208 is close to the side of the battery cell, effectively adapting to the assembly shape of the battery cell, thereby effectively reducing the overall volume of the assembled battery cell assembly, and making the overall shape of the battery cell assembly regular, which facilitates the subsequent stacking of the battery cell assemblies and can effectively improve the energy density of the battery cell assembly.

[0068] It should be noted that the drain section 2051, the connecting section 2052, and the bending section 2053 are connected sequentially along the length of the battery cell unit. That is, the drain section 2051 is connected to the connecting section 2052, and the bending section 2053 is connected to the side of the connecting section 2052 away from the drain section 2051. In addition, the thickness direction, the length direction, and the width direction of the battery cell unit are arranged perpendicularly to each other.

[0069] Referring to Figures 3(a) and 3(b), a stress relief section connects the connecting section 2052 and the bending section 2053. This stress relief section is bent, and multiple bending stress holes 2054 are provided along the bending line of the stress relief section, spaced apart. Therefore, during cell assembly, when bending the bending section 2053, the stress relief section and the bending stress holes 2054 alleviate the stress generated during bending, preventing irregular protrusions or breaks at the bending position.

[0070] It should be noted that the bending line extends along the width direction of the connecting section 2052, and the drain section 2051, connecting section 2052, and bending section 2053 are integrally formed. This is to enhance the overall strength of the positive electrical connector 205 and the negative electrical connector 208, making the bending section 2053 less prone to breakage during bending.

[0071] Specifically, the battery cell assembly described in this embodiment uses two sets of paired dual-cells as shown in Figure 2(a). The positive electrode tab 102 and negative electrode tab 103 of the lower cell 10 in the dual-cell assembly are laser-welded to the current-draining section 2051 of the positive connector 205 and the current-draining section 2051 of the negative connector 208, respectively. Then, the two sets of dual-cells are combined and the above four-cell assembly is fixed by the binding strap 104. The positive electrode pin and the negative electrode pin are bent at 90° along the bending stress hole 2054. At this time, the bending section 2053 is located at the four-cell assembly. After the four cells are combined, the middle positions of the corresponding tabs of the two middle cells are then folded at 90° and attached tightly to the bending sections 2053 of the positive and negative connectors 208, respectively. The positive tab 102 is then welded to the bending section 2053 of the positive connector 205 and the negative connector 208, respectively, using a laser. The negative tab 103 is then welded to the bending section 2053 of the positive connector 208, thus achieving the parallel four-cell battery assembly described in this embodiment.

[0072] Specifically, a housing with openings at both ends contains eight battery cells 10. Four battery cells 10 on one side are connected in parallel with each other, and four battery cells 10 on the other side are connected in parallel with each other. The battery cells 10 on both sides are isolated from each other by an insulating film 30 to avoid short circuits.

[0073] Example 2

[0074] like Figure 1 and Figure 6 As shown, the difference between this embodiment 2 and embodiment 1 lies in the different structures of the positive electrical connector 205 and the negative electrical connector 208, as well as the different arrangement of the battery cells. In this embodiment, the width of the bending area is greater than the width of the drainage area, and the number of battery cells 10 is four. The positive electrode tabs 102 and negative electrode tabs 103 of the two middle battery cells 10 are located on the first side, and the positive electrode tabs 102 and negative electrode tabs 103 of the two battery cells on the two sides are located on the second side. The two positive electrode tabs 102 on the second side are arranged opposite to each other in the thickness direction, and the two negative electrode tabs 103 on the second side are arranged opposite to each other in the thickness direction. The two positive electrode tabs 102 on the first side are arranged opposite to each other in the thickness direction, and the two negative electrode tabs 103 on the first side are arranged opposite to each other in the thickness direction.

[0075] In the above technical solution, by setting the width of the bending area to be greater than the width of the drainage area, the two positive electrode tabs 102 and the two negative electrode tabs 103 that are set opposite to each other on the second side can be easily electrically connected to the bending area in the thickness direction, so as to ensure the stability of the electrical connection.

[0076] Additionally, see Figure 6The four battery cells are secured with multiple straps 104 to enhance the stability of the battery cell assembly during assembly.

[0077] Secondly, in this embodiment, the positive tab 102 and negative tab 103 corresponding to the two battery cells 10 are directly soldered to the current-guiding section 2051 on the pin; the two battery cells 10 are combined; the bending section 2053 on the pin is bent; another battery cell 10 is placed on top of and below the two combined battery cells 10; and the positive and negative tabs 103 are soldered to the bending section 2053.

[0078] Specifically, the battery cell assembly described in this second embodiment uses... Figure 1 The two battery cells 10 with their tabs folded together are shown. The positive tab 102 and negative tab 103 of each battery cell 10 are laser-welded to the current-draining section 2051 of the positive connector 205 and the current-draining section 2051 of the negative connector 208, respectively. Then, the two battery cells 10 are joined together to obtain a dual-cell structure. Next, the positive and negative leads are bent 90° along the bending stress hole 2054, so that the bent section 2053 fits against the tail of the dual-cell structure. Then, two... Figure 1 The battery cell 10, after the tabs are folded up, is placed on the upper and lower surfaces of the dual-cell structure, such that the bent section 2053 of the positive connector 205 and the bent section 2053 of the negative connector 208 are located in the middle area of ​​the two sets of positive tabs 102 and the two sets of negative tabs 103, respectively, using the binding strap 104 ( Figure 6 (Not shown) Fix the above four battery cells 10; finally, bend the two sets of positive tabs 102 and the two sets of negative tabs 103 corresponding to the two battery cells 10 by 90° respectively, and attach them tightly to the bending section 2053 of the positive electrical connector 205 and the bending section 2053 of the negative electrical connector 208 respectively. Weld the positive tabs 102 to the bending section 2053 of the positive electrical connector 205 together by laser, and weld the negative tabs 103 to the bending section 2053 of the negative electrical connector 208 together, thus achieving the parallel battery cell assembly of four battery cells described in this embodiment two.

[0079] The other structures in this second embodiment are the same as those in the first embodiment, and will not be described again here.

[0080] Example 3

[0081] like Figure 1 and Figure 7 As shown, the difference between this embodiment three and embodiment one is that the two middle cells of the four cells are provided with multiple binding straps 104 around their outer periphery; the four cells are provided with multiple binding straps 104 around their outer periphery. This is to ensure the stability of the two middle cells 10 during assembly, and then bind and fix the four cells 10 to further ensure that the cells 10 will not deflect or shift during assembly.

[0082] In addition, in this third embodiment, the positive tabs 102 and negative tabs 103 corresponding to the two battery cells 10 are respectively welded to the current-guiding section 2051 on the pin; then the battery cells are stacked to obtain a paired dual battery cell; the above-mentioned paired dual battery cell is placed inside the space constructed by the positive and negative pins; the two battery cells 10 are combined; the bending section 2053 on the pin is bent; and the positive tabs 102 and negative tabs 103 corresponding to the paired dual battery cell are respectively welded to the bending section 2053.

[0083] Specifically, the battery cell assembly described in this embodiment three adopts... Figure 1 The two battery cells 10 with their tabs folded together are shown. The positive tab 102 and negative tab 103 of the battery cells 10 are laser-welded to the current-draining section 2051 of the positive connector 205 and the current-draining section 2051 of the negative connector 208, respectively. Then take two... Figure 1 After the electrode tabs of the battery cell 10 are folded together, two battery cells 10 are stacked along their thickness direction. At this time, the positive electrode tabs 102 and negative electrode tabs 103 of the two battery cells 10 are located on the same side along their length direction. The positive electrode tabs 102 and negative electrode tabs 103 of the lower battery cell 10 are folded to the lower side along their thickness direction, while the positive electrode tabs 102 and negative electrode tabs 103 of the upper battery cell 10 are folded to the upper side along their thickness direction. The two battery cells 10 are fixed with multiple binding straps 104 to obtain a dual-cell structure. Then, the dual-cell structure is placed in the receiving space formed by the positive and negative electrode pins. At this time, the positive electrode tabs 102 and negative electrode tabs 103 are close to the positive and negative electrode pins, respectively. Then, the two battery cells 10 are joined together, and the positive and negative electrode pins are aligned along the bending stress. The hole 2054 is bent at 90° so that the bent section 2053 of the positive electrical connector 205 and the bent section 2053 of the negative electrical connector 208 are located in the middle area of ​​the two sets of positive tabs 102 and the two sets of negative tabs 103, respectively. Finally, the two sets of positive tabs 102 and the two sets of negative tabs 103 corresponding to the two middle battery cells 10 are bent at 90° and respectively attached tightly to the bent section 2053 of the positive electrical connector 205 and the bent section 2053 of the negative electrical connector 208. The positive tab 102 is welded to the bent section 2053 of the positive electrical connector 205 and the negative tab 103 is welded to the bent section 2053 of the negative electrical connector 208 by laser. Finally, the four battery cells 10 are fixed by the binding strap 104, thus achieving the four-cell parallel battery cell assembly described in this embodiment three.

[0084] The other structures in this embodiment three are the same as those in embodiment one, and will not be described again here.

[0085] Example 4

[0086] like Figures 8 to 10As shown, the difference between this fourth embodiment and the first embodiment is that the connecting section 2052 and the bending section 2053 are integrally formed, while the drain section 2051 and the connecting section 2052 are separate and welded together. This allows for cell assembly without the connecting section 2052, followed by welding and fixing of the connecting section 2052. This provides more assembly methods to adapt to different assembly environments, thus facilitating cell assembly operations.

[0087] See Figure 8 as well as Figure 9 The lead-in section 2051 is provided with a first step groove, which is located on the side of the lead-in section 2051 away from the cell unit to form a first step; the connecting section 2052 is provided with a second step groove, which is located on the side of the connecting section 2052 facing the cell unit to form a second step. The first step and the second step are fastened and welded together.

[0088] In the above technical solution, by setting the first step and the second step, the two sets of step grooves can be directly aligned when connecting the connecting section 2052 and the diversion section 2051. Then, welding can be carried out directly according to the position of the step groove, avoiding the problem of welding position deviation or misalignment between the diversion section 2051 and the connecting section 2052. This effectively improves the cell assembly efficiency while ensuring structural strength.

[0089] Furthermore, in the battery cell assembly described in this embodiment four, the bending section 2053 has been bent at 90° through the bending stress hole 2054. In this embodiment four, after the two paired dual battery cells 10 are joined together, the bending section 2053 is fitted onto the two middle battery cells 10, and then the first step groove on the current-leading section 2051 and the second step groove on the connecting section 2052 are fastened together and welded by laser. Finally, the tabs on the two middle battery cells 10 are welded onto the bending section 2053.

[0090] Specifically, the battery cell assembly described in this embodiment four, such as Figure 10 As shown, it uses two sets of paired dual-cell batteries, with the positive tab 102 and negative tab 103 corresponding to the lower cell 10 of the dual-cell battery being laser-welded to the battery. Figure 8 The positive terminal connector 205 and the negative terminal connector 208 are shown on the lead-in section 2051; then the two sets of dual-cell batteries are joined together, and the four-cell batteries are fixed with the binding strap 104; then... Figure 9The connecting segments 2052 and 2053 of the positive connector 205 and the connecting segments 2052 and 2053 of the negative connector 208 are respectively fitted onto the middle sections of the two sets of positive tabs 102 and two sets of negative tabs 103 corresponding to the two middle battery cells. At this time, the second and first stepped grooves of the positive pins are engaged and welded by laser; the second and first stepped grooves of the negative pins are engaged and welded by laser. Subsequently, the two middle battery cells... Two sets of positive tabs 102 and two sets of negative tabs 103 are bent at 90° and respectively attached to the bent sections 2053 of the positive connector 205 and the negative connector 208. The positive tabs 102 are welded to the bent sections 2053 of the positive connector 205 and the negative tabs 103 are welded to the bent sections 2053 of the negative connector 208 by laser welding, thus achieving the four-cell parallel cell assembly described in this embodiment four.

[0091] The other structures in this embodiment four are the same as those in embodiment one, and will not be described again here.

[0092] Example 5

[0093] like Figure 11 As shown, the difference between this fifth embodiment and the second embodiment lies in the specific structures of the positive connector 205 and the negative connector 208. The current-draining section 2051 and the connecting section 2052 are separately arranged and welded together, and the stacking method of the four cells is different. In this fifth embodiment, after obtaining the four-cell stacked structure, the bending section 2053 is fitted onto the two outer cells 10. Then, the first step groove on the current-draining section 2051 and the second step groove on the connecting section 2052 are fastened together and welded by laser. Finally, the tabs on the two outer cells 10 are welded onto the bending section 2053. Specifically, the cell assembly described in this fifth embodiment uses two cells 10, and the positive tab 102 and negative tab 103 corresponding to the cells 10 are welded onto the connecting section 2052 by laser. Figure 8 The positive terminal connector 205 and the negative terminal connector 208 are shown in the lead-in section 2051; then the two battery cells 10 are combined to obtain a dual-cell structure; then two more are taken Figure 1 The battery cells 10, after the tabs have been folded up, are placed on the upper and lower surfaces of the aforementioned dual-cell structure. At this time, the positive tab 102 and negative tab 103 corresponding to the uppermost battery cell 10 are folded up on the upper side of the cell thickness direction, and the positive tab 102 and negative tab 103 corresponding to the lowermost battery cell 10 are folded up on the lower side of the cell thickness direction. The four battery cells 10 are then secured using binding straps 104. IV. [The text abruptly ends here, likely due to an incomplete translation or a formatting error.] Figure 9The connecting segments 2052 and 2053 of the positive connector 205 and the connecting segments 2052 and 2053 of the negative connector 208 are respectively fitted onto the middle sections of the two sets of positive tabs 102 and two sets of negative tabs 103 corresponding to the two outermost battery cells. At this time, the first and second stepped grooves of the positive pins are engaged and welded by laser; the first and second stepped grooves of the negative pins are engaged and welded by laser; the two outermost battery cells... Two sets of positive tabs 102 and two sets of negative tabs 103 are bent at 90° and respectively attached to the bent sections 2053 of the positive connector 205 and the negative connector 208. The positive tabs 102 are welded to the bent sections 2053 of the positive connector 205 and the negative tabs 103 are welded to the bent sections 2053 of the negative connector 208 by laser welding, thus achieving the four-cell parallel cell assembly described in this embodiment five.

[0094] The other structures in this fifth embodiment are the same as those in the second embodiment, and will not be described again here.

[0095] Example 6

[0096] like Figure 12 As shown, the difference between this embodiment six and embodiment two is that the specific structures of the positive electrical connector 205 and the negative electrical connector 208 are different, the current-draining section 2051 and the connecting section 2052 are separately set and welded together, and the stacking method of the four cells is different. In this embodiment, after the two cells 10 are combined to obtain a double-cell structure, two more cells 10 are taken and their positive electrode tabs 102 and negative electrode tabs 103 are welded to the bending section 2053 of the positive electrical connector 205 and the bending section 2053 of the negative electrical connector 208, respectively. Then, the connecting section 2052 and the bending section 2053 of the positive electrical connector and the connecting section 2052 and the bending section 2053 of the negative electrical connector are sleeved on the outside of the double-cell structure. Finally, the first step groove on the current-draining section 2051 and the second step groove on the connecting section 2052 are fastened together and welded by laser. Specifically, the battery cell assembly described in this embodiment six uses two battery cells 10, and the positive electrode tab 102 and negative electrode tab 103 corresponding to the battery cells 10 are respectively welded to the battery cells using laser welding. Figure 8 The positive terminal connector 205 and the negative terminal connector 208 are shown in the lead-in section 2051; then the two battery cells 10 are combined to obtain a dual-cell structure; then two more are taken Figure 1 After the battery cell 10 with its tabs folded together is shown, the positive tab 102 and negative tab 103 corresponding to the battery cell 10 are welded to the battery cell 10 by ultrasonic or laser welding. Figure 9The positive connector 205 and the negative connector 208 are bent into sections 2053. The corresponding connecting sections 2052 of the positive connector 205 and the negative connector 208 are respectively fitted onto both sides of the width direction of the above-mentioned dual-cell structure until the first step groove and the second step groove of the positive electrode pin are engaged and welded by laser. The second step groove and the first step groove of the negative electrode pin are engaged and welded by laser. The two cells 10 are joined together. Finally, the four cells 10 are fixed by the binding strap 104, thus achieving the four-cell parallel cell assembly described in this embodiment six.

[0097] The other structures in this embodiment six are the same as those in embodiment two, and will not be described again here.

[0098] Example 7

[0099] like Figure 13 As shown, the difference between this embodiment seven and embodiment three is that the specific structures of the positive electrical connector 205 and the negative electrical connector 208 are different in this embodiment. The current-draining section 2051 and the connecting section 2052 are set separately and welded together. The stacking method of the four cells is different. After stacking two cells 10 to obtain a paired double cell, the bent sections 2053 of the positive electrical connector 205 and the negative electrical connector 208 are respectively fitted onto the paired double cell. Then, the first step groove on the current-draining section 2051 and the second step groove on the connecting section 2052 are fastened and welded together.

[0100] Specifically, the battery cell assembly described in Embodiment Seven uses two battery cells 10, with the positive tab 102 and negative tab 103 corresponding to the battery cells 10 respectively welded to the battery cells using laser welding. Figure 8 On the positive current connector 205's lead-in section 2051 and the negative current connector 208's lead-in section 2051; II. Take two more Figure 1 The battery cell 10, after its tabs are folded together, is stacked along its thickness direction. The positive tab 102 and negative tab 103 of the lower battery cell 10 are folded to the lower side of its thickness direction, while the positive tab 102 and negative tab 103 of the upper battery cell 10 are folded to the upper side of its thickness direction. Finally, the two battery cells 10 are secured with binding straps 104. III. [The text abruptly ends here, likely due to an incomplete translation or missing information.] Figure 9The bending segments 2053 corresponding to the positive electrical connector 205 and the negative electrical connector 208 shown are respectively fitted onto the middle sections of the two sets of positive electrode tabs 102 and the two sets of negative electrode tabs 103 mentioned in step two; Fourth, the two sets of positive electrode tabs 102 mentioned in step two are bent at 90° and laser welded to the bending segments 2053 of the positive electrical connector 205, and the two sets of negative electrode tabs 103 are bent at 90° and laser welded to the bending segments 2053 of the negative electrical connector 208; Fifth, the dual battery cells mentioned in step four are placed on the cover plate 20 of step one, the first step groove and the second step groove of the positive electrode pin are fastened together and laser welded; the first step groove and the second step groove of the negative electrode pin are fastened together and laser welded; Sixth, the two battery cells 10 of step one are combined and the four battery cells 10 are fixed by the binding strap 104.

[0101] The other structures in this embodiment seven are the same as those in embodiment three, and will not be described again here.

[0102] Example 8

[0103] like Figure 14 As shown, the difference between Embodiment 8 and Embodiment 6 is that the number of battery cells is four, and the four battery cells are divided into two battery cell groups. Each battery cell group includes two battery cells stacked along the thickness direction. Along the length direction of the battery cells, the two battery cell groups are arranged along the length direction. Along the length direction, the current-draining area and the bending area are located on both sides of the first battery cell group. The positive electrode tabs 102 of the first battery cell group are all electrically connected to the current-draining area of ​​the positive electrical connector 205, and the negative electrode tabs 103 of the first battery cell group are all electrically connected to the current-draining area of ​​the negative electrical connector 208. The positive electrode tabs 102 of the second battery cell group are all electrically connected to the bending area of ​​the positive electrical connector 205, and the negative electrode tabs 103 of the second battery cell group are all electrically connected to the bending area of ​​the negative electrical connector 208.

[0104] In the above technical solutions, the four-cell parallel structure obtained in Embodiments 1 to 7 is formed by stacking the four cells 10 along their thickness direction; in this Embodiment 8, the four-cell parallel structure obtained can be regarded as two dual-cell structures arranged along their length direction to provide a completely different four-cell parallel structure to adapt to different assembly processes and further expand the final assembly form, so that the cell assembly can be adapted to external limiting structures of different shapes or forms.

[0105] It should be noted that, Figure 14 The two cells on the left are the first cell group, and the two cells on the right are the second cell group.

[0106] Specifically, the battery cell assembly described in this embodiment eight uses two battery cells 10 with the tabs folded together. The positive tab 102 and negative tab 103 corresponding to the battery cells 10 are respectively welded to the battery cell assembly using laser welding. Figure 8 The positive terminal connector 205 and the negative terminal connector 208 are shown as follows: 2. The two battery cells 10 are joined together and fixed with multiple binding straps 104 to obtain a dual-cell structure; 3. Two more are taken... Figure 1 The battery cell 10, after the tabs are folded together, is stacked along its thickness direction. The positive tab 102 and negative tab 103 of the lower battery cell 10 are folded to the lower side of its thickness direction, while the positive tab 102 and negative tab 103 of the upper battery cell 10 are folded to the upper side of its thickness direction. Finally, the two battery cells 10 are secured with multiple binding straps 104. IV. [The text abruptly ends here, likely due to an incomplete translation or missing information.] Figure 9 The bending segments 2053 corresponding to the positive electrical connector 205 and the negative electrical connector 208 shown are respectively placed in the segment area between the two sets of positive electrode tabs 102 and the two sets of negative electrode tabs 103 mentioned in step three; Fifth, the two sets of positive electrode tabs 102 mentioned in step three are bent by 90° and laser welded to the bending segment 2053 of the positive electrical connector 205, and the two sets of negative electrode tabs 103 are bent by 90° and laser welded to the bending segment 2053 of the negative electrical connector 208; Sixth, the first step groove and the second step groove of the positive electrode pin mentioned in step five are fastened together and laser welded; the first step groove and the second step groove of the negative electrode pin are fastened together and laser welded.

[0107] The other structures of this embodiment eight are the same as those of embodiment six, and will not be described again here.

[0108] This invention divides a four-cell battery into two sets of dual-cell batteries, with the corresponding tabs of the two sets of dual-cell batteries located at both ends of the length of the battery cell 10. The tabs of one set of dual-cell batteries are welded to the current-guiding section 2051 of the pin, while the tabs of the other set are welded to the bending section 2053 of the pin. The pin can be a single-piece structure or a separate structure. In the separate structure, the pin consists of the current-guiding section 2051, the connecting section 2052, and the bending section 2053. The current-guiding section 2051 is used to weld the tabs of one set of dual-cell batteries, while the connecting section 2052 and the bending section 2053 are integrally formed and used to weld the tabs of the other set of dual-cell batteries. The first stepped groove of the current-guiding section 2051 and the second stepped groove of the connecting section 2052 are fastened and welded together, thereby achieving parallel connection of the four-cell battery tabs. Finally, the two sets of parallel-welded four-cell units are inserted into a housing with openings at both ends, thus completing the battery cell assembly of the lithium battery.

[0109] In summary, the present invention has the following advantages:

[0110] 1. Compared with the traditional four-cell assembly method, the present invention independently welds the corresponding tabs of the cells to the current-leading section 2051 or bending section 2053 on the pin. There is no need to close the tabs between individual cells, which reduces the number of tab welding layers and greatly reduces the risk of tab tearing and poor soldering during the ultrasonic welding process.

[0111] 2. This invention is applicable to short electrode application scenarios. The electrode is welded to the drainage section 2051 and the core is completed. The electrode is bent at 90° and welded to the bending section 2053. Both present a "C" shape, which reduces the risk of electrode insertion.

[0112] 3. In the traditional four-cell assembly method, the four-cell parallel structure is usually inserted into a housing with one open end. However, the present invention inserts two four-cell parallel structures into a housing with two open ends. Due to the reduction in the number of tab layers, the gap between the tab and the cover plate is reduced. The bottom restriction of the traditional housing is eliminated between the two four-cell parallel structures, thus improving the energy density of the entire lithium battery.

[0113] Embodiments of the present invention also provide a lithium battery, including a cover plate 20, a housing 40, and a cell assembly according to any of the above embodiments. The cell assembly is disposed within the housing 40, and the cover plate 20 covers the housing 40. The current-draining area of ​​the positive electrical connector 205 is electrically connected to the positive terminal 203 of the cover plate 20, and the current-draining area of ​​the negative electrical connector 208 is electrically connected to the negative terminal 204 of the cover plate 20. The housing 40 is used to protect and limit the cell assembly.

[0114] In existing technologies, a large gap exists between the multi-layer tabs and the cover plate, reducing the energy density of a single lithium battery cell. Therefore, as... Figure 4 As shown, in some embodiments, the outer casing 40 is a cylindrical structure with openings at both ends. The lithium battery includes two cell assemblies and two cover plates 20. The two cover plates 20 are respectively covered at both ends of the outer casing 40. The two cell assemblies are arranged back to back inside the outer casing 40, and the two cell assemblies are insulated from each other by an insulating film 30.

[0115] In the above technical solution, after the assembly of the battery cell assembly is completed, an insulating film 30 is wrapped on the outer surface of the battery cell assembly to prevent the battery cell from being scratched during the subsequent battery cell insertion process; two battery cell assemblies are respectively inserted into a housing 40 with openings at both ends, and finally the substrates 201 corresponding to the two sets of cover plates 20 are welded to the two side ports of the housing 40 by laser. Due to the reduction of the number of tab layers, the gap between the tabs and the cover plates is reduced, and the bottom restriction in the traditional housing is eliminated between the two four-cell parallel structures, thus improving the energy density of the entire lithium battery.

[0116] As shown in Figure 3, in some embodiments, the cover plate 20 is further provided with a substrate 201 and an insulating gasket 202. The substrate 201 is also provided with an explosion-proof valve 2011 and a liquid injection hole 2012. This allows the gas to be discharged through the explosion-proof valve 2011 and the liquid injection hole 2012 to be used for subsequent lithium battery applications if gas is released during use.

[0117] Specifically, the positive terminal 203 and the negative terminal 204 are isolated from the substrate 201 by insulating pads (not shown).

[0118] The present invention also provides a method for assembling a lithium battery cell assembly, which is used to assemble the aforementioned lithium battery cell assembly.

[0119] In some embodiments, the assembly method of the lithium battery cell assembly includes: along the thickness direction of the cell 10, gathering both the positive tab 102 and the negative tab 103 to one side of the cell body 101; independently setting the positive tab 102 of a portion of the multiple cells and electrically connecting them to the current-draining area of ​​the positive connector 205; independently setting the positive tab 102 of the remaining cells of the multiple cells 10 and electrically connecting them to the bending area of ​​the positive connector 205; independently setting the negative tab 103 of the aforementioned portion of the cells 10 and electrically connecting them to the current-draining area of ​​the negative connector 208, and independently setting the negative tab 103 of the remaining cells 10 and electrically connecting them to the bending area, so that the multiple cells 10 are arranged in parallel.

[0120] In the above technical solution, by spacing the positive tab 102 and negative tab 103 and bringing them together to one side, and by independently welding the positive tab 102 of a portion of the multiple battery cells to the current-guiding area of ​​the positive connector 205, and independently welding the negative tab 103 of the aforementioned portion of the battery cells to the current-guiding area of ​​the negative connector 208; and by independently welding the positive tab 102 of the remaining multiple battery cells to the bending area of ​​the positive connector 205, and independently welding the negative tab 103 of the remaining battery cells to the bending area of ​​the negative connector 208, an electrical connection is established, facilitating the connection of each battery cell 102. While stacking the cells, the tabs between each cell 10 do not need to be joined together, allowing multiple cells 10 to be connected in parallel. This avoids increasing the number of tab layers and the overall thickness of the tabs, thus effectively preventing the problems of outer tab tearing and inner tab cold solder joints that are easily caused by the multi-layer joining and welding operations required in traditional parallel connection methods. Therefore, the cell assembly of the present invention can be stacked and connected in parallel without increasing the tab length and welding thickness, greatly reducing the risk of tab tearing and cold solder joints during ultrasonic welding, and effectively reducing structural risks.

[0121] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: by setting the positive and negative tabs alternately and gathering them to one side, and by independently welding the positive tabs of a portion of the multiple battery cells to the current-guiding area of ​​the positive connector, and independently welding the negative tabs of the aforementioned portion of the battery cells to the current-guiding area of ​​the negative connector; and by independently welding the positive tabs of the remaining multiple battery cells to the bending area of ​​the positive connector, and independently welding the negative tabs of the remaining battery cells to the bending area of ​​the negative connector, an electrical connection is established, facilitating the stacking of the battery cells. The design eliminates the need for the tabs between individual cells to be joined together, allowing multiple cells to be connected in parallel. This avoids increasing the number of tab layers and the overall thickness of the tabs, effectively preventing the problems of outer tab tearing and inner tab cold solder joints that are common in traditional parallel connection methods that require multi-layer joining and welding of the tabs. Therefore, the cell assembly of this invention can be connected in parallel with multiple cells without increasing the tab length and welding thickness, greatly reducing the risk of tab tearing and cold solder joints during ultrasonic welding, and effectively reducing structural risks.

[0122] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A battery cell assembly, characterized in that, include: A battery cell unit includes multiple battery cells, each of which includes a battery cell body (101), a positive electrode tab (102), and a negative electrode tab (103). The positive electrode tab (102) and the negative electrode tab (103) are spaced apart along the width direction of the battery cell, and along the thickness direction of the battery cell, the positive electrode tab (102) and the negative electrode tab (103) are both gathered to one side of the battery cell body (101). Both the positive connector (205) and the negative connector (208) have a current-draining area and a bending area. The positive tabs (102) of a portion of the multiple battery cells are independently arranged and electrically connected to the current-draining area of ​​the positive connector (205). The positive tabs (102) of the remaining multiple battery cells are independently arranged and electrically connected to the bending area of ​​the positive connector (205). The negative tabs (103) of the portion of the battery cells are independently arranged and electrically connected to the current-draining area of ​​the negative connector (208). The negative tabs (103) of the remaining battery cells are independently arranged and electrically connected to the bending area, so that the multiple battery cells are arranged in parallel.

2. The battery cell assembly according to claim 1, characterized in that, Multiple battery cells are arranged sequentially along the thickness direction of the battery cells. In the length direction of the battery cells, the battery cell body (101) has a first side and a second side arranged opposite to each other. The positive electrode tab (102) and negative electrode tab (103) of a portion of the battery cells are located on the first side, and the positive electrode tab (102) and negative electrode tab (103) of the remaining battery cells are located on the second side. Along the length direction, the draining area and the bending area are respectively located on both sides of the battery cell. The plurality of positive tabs (102) located on the first side are independently arranged and are all electrically connected to the draining area of ​​the positive electrical connector (205). The plurality of negative tabs (103) located on the first side are independently arranged and are all electrically connected to the draining area of ​​the negative electrical connector (208). The plurality of positive tabs (102) located on the second side are independently arranged and are all electrically connected to the bending area of ​​the positive electrical connector (205). The plurality of negative tabs (103) located on the second side are independently arranged and are all electrically connected to the bending area of ​​the negative electrical connector (208).

3. The cell assembly according to claim 2, characterized in that, The width of the drainage area is greater than the width of the bending area, and the number of battery cells is four. The positive tabs (102) and negative tabs (103) of the two middle cells of the four cells are located on the second side, and the positive tabs (102) and negative tabs (103) of the two cells on both sides of the four cells are located on the first side. The two positive tabs (102) located on the second side are arranged opposite to each other in the thickness direction, the two negative tabs (103) located on the second side are arranged opposite to each other in the thickness direction, the two positive tabs (102) located on the first side are arranged opposite to each other in the thickness direction, and the two negative tabs (103) located on the first side are arranged opposite to each other in the thickness direction.

4. The cell assembly according to claim 3, characterized in that, The outer periphery of the first and second of the four battery cells is provided with multiple binding straps (104), and the outer periphery of the third and fourth of the four battery cells is provided with multiple binding straps (104). The four battery cells are provided with multiple binding straps (104) around their outer periphery.

5. The cell assembly according to claim 3, characterized in that, The outer periphery of the two middle cells of the four cells is provided with multiple binding straps (104). The four battery cells are provided with multiple binding straps (104) around their outer periphery.

6. The cell assembly according to claim 2, characterized in that, The width of the bending area is greater than the width of the drainage area, and the number of battery cells is four. The positive tabs (102) and negative tabs (103) of the two middle cells of the four cells are located on the first side, and the positive tabs (102) and negative tabs (103) of the two cells on the sides of the four cells are located on the second side. The two positive tabs (102) located on the second side are arranged opposite to each other in the thickness direction, the two negative tabs (103) located on the second side are arranged opposite to each other in the thickness direction, the two positive tabs (102) located on the first side are arranged opposite to each other in the thickness direction, and the two negative tabs (103) located on the first side are arranged opposite to each other in the thickness direction.

7. The cell assembly according to claim 6, characterized in that, The four cells are secured by multiple binding straps (104).

8. The cell assembly according to claim 1, characterized in that, Both the positive electrical connector (205) and the negative electrical connector (208) include a draining section (2051), a connecting section (2052), and a bending section (2053) connected in sequence. The draining section (2051) is set at an angle to the connecting section (2052), and the bending section (2053) is set at an angle to the connecting section (2052). Along the thickness direction of the connecting section (2052), the draining section (2051) and the bending section (2053) are located on the same side of the connecting section (2052). The draining section (2051) forms the draining area, and the bending section (2053) forms the bending area.

9. The cell assembly according to claim 8, characterized in that, A stress relief section is connected between the connecting section (2052) and the bending section (2053). The stress relief section is bent and has a plurality of bending stress holes (2054) on the bending line. The plurality of bending stress holes (2054) are spaced apart along the bending line.

10. The cell assembly according to any one of claims 8, characterized in that, The drainage section (2051), the connecting section (2052), and the bending section (2053) are integrally formed.

11. The cell assembly according to any one of claims 8, characterized in that, The connecting section (2052) and the bending section (2053) are integrally formed, while the drainage section (2051) and the connecting section (2052) are separately formed and welded together.

12. The cell assembly according to claim 11, characterized in that, The lead-in section (2051) is provided with a first step groove, which is located on the side of the lead-in section (2051) away from the cell unit to form a first step; The connecting section (2052) is provided with a second step groove, which is located on the side of the connecting section (2052) facing the cell unit to form a second step. The first step and the second step are snapped together and welded.

13. The cell assembly according to claim 1, characterized in that, The number of battery cells is four, and the four battery cells are divided into two battery cell groups. Each battery cell group includes two battery cells stacked along the thickness direction. Along the length direction of the battery cells, the two battery cell groups are arranged along the length direction. Along the length direction, the drainage area and the bending area are respectively located on both sides of the first battery cell group in the two battery cell groups. The positive tabs (102) of the first battery cell group are all electrically connected to the current-draining area of ​​the positive electrical connector (205), the negative tabs (103) of the first battery cell group are all electrically connected to the current-draining area of ​​the negative electrical connector (208), the positive tabs (102) of the second battery cell group are all electrically connected to the bending area of ​​the positive electrical connector (205), and the negative tabs (103) of the second battery cell group are all electrically connected to the bending area of ​​the negative electrical connector (208).

14. A lithium battery, characterized in that, The device includes a cover plate (20), a housing (40), and a cell assembly according to any one of claims 1 to 13, wherein the cell assembly is disposed within the housing (40), the cover plate (20) covers the housing (40), the positive terminal (203) of the cover plate (20) is electrically connected to the positive terminal (203) of the positive terminal (205), and the negative terminal (204) of the cover plate (20) is electrically connected to the negative terminal (204) of the cover plate (20).

15. The lithium battery according to claim 14, characterized in that, The outer casing (40) is a cylindrical structure with openings at both ends. The lithium battery includes two battery cell assemblies and two cover plates (20). The two cover plates (20) are respectively installed on both ends of the outer casing (40). The two battery cell assemblies are arranged back to back inside the outer casing (40). The two battery cell assemblies are insulated from each other by an insulating film (30).

16. A method for assembling a lithium battery cell assembly, characterized in that, The method for assembling the cell assembly of the lithium battery is used to assemble the cell assembly of the lithium battery according to any one of claims 1 to 13.

17. The method for assembling a lithium battery cell assembly according to claim 16, characterized in that, The assembly method of the lithium battery cell assembly includes: Along the thickness direction of the battery cell, both the positive electrode tab (102) and the negative electrode tab (103) are brought together to one side of the battery cell body (101); The positive tabs (102) of a portion of the multiple battery cells are independently set and electrically connected to the current-draining area of ​​the positive electrical connector (205); the positive tabs (102) of the remaining multiple battery cells are independently set and electrically connected to the bending area of ​​the positive electrical connector (205); The negative electrode tabs (103) of a portion of the battery cells are set independently and electrically connected to the current-draining area of ​​the negative electrical connector (208). The negative electrode tabs (103) of the remaining battery cells are set independently and electrically connected to the bending area, so that multiple battery cells are set in parallel.

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