Battery cell structure, assembly process method of battery cell structure and large energy storage battery

Abstract

The invention provides a battery cell structure, an assembly process method of the battery cell structure and a large energy storage battery, the battery cell structure comprises a cover plate and two adapter sheet structures, the cover plate is provided with two pole columns arranged at intervals along the Y direction, each adapter sheet structure comprises a pole column connecting part, the pole column connecting part is provided with a first side, and the first side is provided with a second side; the first side is provided with a cleaning area for cleaning treatment, the cleaning area comprises a welding area and an annular area surrounding the periphery of the welding area, and the welding area is used for welding and fixing the pole connecting part and the pole, so that the welding area is ensured to be in a clean state before welding, welding defects caused by impurities, oxides and the like are avoided, and the welding quality is improved. Therefore, the welding strength and reliability of the pole connecting part and the pole are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and particularly to a battery cell structure, an assembly process method of the battery cell structure, and a large energy storage battery. Background Art

[0002] A battery cell structure usually includes a cover plate and a connecting piece structure. The cover plate is provided with pole columns. Usually, the pole columns and the connecting piece structure are fixed by welding. However, since foreign matters adhere to the welding area of the connecting piece structure or an oxide layer exists, the welding between the connecting piece structure and the pole columns will be defective. Summary of the Invention

[0003] Embodiments of the present invention provide a battery cell structure, an assembly process method of the battery cell structure, and a large energy storage battery, which can improve the problem that the welding between the connecting piece structure and the pole columns will be defective due to foreign matters adhering to the welding area or an oxide layer existing.

[0004] In a first aspect, embodiments of the present invention provide a battery cell structure.

[0005] In one embodiment, the battery cell structure includes:

[0006] A cover plate, the cover plate is provided with two pole columns arranged at intervals along the Y direction;

[0007] Two connecting piece structures, each of the connecting piece structures includes a pole column connecting portion. The pole column connecting portion has a first side, and the first side has a cleaning area for being cleaned. The cleaning area includes a welding area and an annular area surrounding the periphery of the welding area. Among them, in the welding area, the pole column connecting portion is welded and fixed to the pole column.

[0008] In one embodiment, the distance between the boundary of the welding area and the outer boundary of the annular area is L, where L≥1.0 mm; and / or,

[0009] The area of the welding area is S1, the area of the cleaning area is S2, and the surface area of the first side is S3, where 0<S1 / S2<1; and / or 0<S2 / S3≤1.

[0010] In one embodiment, the depth of the cleaning area is H, where 0.5 μm≤H≤1000 μm.

[0011] In one embodiment, the cleaning area is formed with a groove and a plurality of protrusions, and the plurality of grooves and the plurality of protrusions are arranged alternately.

[0012] In one embodiment, two battery cells are further included, the two battery cells are arranged at intervals along the X direction, each of the battery cells has a first pole ear and a second pole ear arranged at intervals along the Y direction, the two first pole ears of the two battery cells are opposite to each other, and the two second pole ears of the two battery cells are opposite to each other;

[0013] Each of the adapter plate structures also includes a pole lug connection portion, which is connected to the pole column connection portion. One of the pole lug connection portions in the two adapter plate structures is connected to the two first pole lugs arranged in opposite positions, and the other pole lug connection portion in the two adapter plate structures is connected to the two second pole lugs arranged in opposite positions.

[0014] In one embodiment, the tab connection portion includes:

[0015] A main body, the main body being connected to the pole connecting portion;

[0016] Two connecting arms, the two connecting arms are arranged opposite to each other and spaced apart, and one end of the two connecting arms is connected to the main body;

[0017] Among them, one of the two connecting arms and / or the main body is connected to one of the two first pole ears arranged in opposite positions, and the other of the two connecting arms and / or the main body is connected to the other of the two first pole ears arranged in opposite positions.

[0018] In one embodiment, the area of ​​the cleaning zone is S2;

[0019] The main body has a second side on the same side as the first side, the surface area of ​​the second side is S4, and the surface area of ​​the first side is S3, wherein S3+S4>S2.

[0020] In a second aspect, an embodiment of the present invention provides an assembly process method of the battery cell structure as described above.

[0021] In one embodiment, the assembly process of the battery cell structure includes the following steps:

[0022] Obtain two adapter plate structures, each of which includes a pole connecting portion, the pole connecting portion having a first side, and perform a cleaning process on the first side to form a cleaning area on the first side, the cleaning area including a welding area and an annular area surrounding the welding area;

[0023] A cover plate is obtained, wherein the cover plate is provided with two poles spaced apart along the Y direction, and the two poles are respectively welded and fixed to the corresponding pole connecting parts at the two welding areas.

[0024] In one embodiment, the step of obtaining two adapter plate structures, each of which includes a pole connecting portion, the pole connecting portion having a first side, and performing a cleaning process on the first side to form a clean area on the first side, wherein the clean area includes a welding area and an annular area surrounding the welding area, comprises:

[0025] The laser device emits laser light under preset conditions to clean the first side of the pole connecting portion.

[0026] In one embodiment, the laser power is P, wherein the preset conditions include: 100W≤P≤700W; and / or,

[0027] The laser frequency is f, wherein the preset conditions include: 100 Hz ≤ f ≤ 800 Hz; and / or,

[0028] The laser scanning speed is V, wherein the preset conditions include: 500mm / s≤V≤20000mm / s.

[0029] In one embodiment, each of the adapter plate structures further includes a pole ear connection portion, the pole ear connection portion is connected to the pole column connection portion, the acquisition cover plate is provided with two poles arranged at intervals along the Y direction, and before the step of respectively welding and fixing the two poles to the corresponding pole column connection portions in the two welding areas, it also includes:

[0030] Obtain two battery cells, each of which has a first pole ear and a second pole ear arranged at intervals along the Y direction, and arrange the two battery cells at intervals along the X direction, so that the two first pole ears of the two battery cells are opposite to each other, and the two second pole ears of the two battery cells are opposite to each other;

[0031] The tab connection portion of one of the two adapter structures is connected to the two first tabs arranged in opposite positions, and the tab connection portion of the other of the two adapter structures is connected to the two second tabs arranged in opposite positions.

[0032] In one embodiment, the step of obtaining a cover plate, wherein the cover plate is provided with two poles spaced apart along the Y direction, and respectively welding and fixing the two poles to the corresponding pole connecting parts at the two welding areas comprises:

[0033] Penetrating one of the two adapter plate structures by laser in one of the two welding areas, so that one of the two adapter plate structures is welded and fixed to one of the two poles; and / or,

[0034] The other one of the two welding areas is penetrated by laser into the other one of the two adapter plate structures, so that the other one of the two adapter plate structures is welded and fixed to the other one of the two poles.

[0035] In a third aspect, an embodiment of the present invention provides a large energy storage battery, including a cell structure assembled by the cell structure assembly process method as described above.

[0036] Beneficial effects of the embodiments of the present invention:

[0037] In an embodiment of the present invention, since the pole connection part is fixed to the pole of the cover plate by welding, the stability and reliability of the overall battery cell structure are improved, and it helps to resist the influence of external factors such as vibration and impact on the connection between the pole connection part and the cover plate. The first side has a clean area for cleaning, and the clean area includes a welding area and an annular area surrounding the welding area. This design is intended to ensure that the welding area is in a clean state before welding, avoiding welding defects caused by impurities, oxides, etc., thereby improving the strength and reliability of the welding between the pole connection part and the pole. A clean welding surface helps to reduce poor contact problems caused by factors such as corrosion and oxidation, thereby extending the service life of the battery cell structure. In addition, the presence of an annular area surrounding the welding area helps to prevent external contaminants from invading the welding area during welding or connection, thereby improving the purity and stability of the connection, and ensuring that the pole connection part and the pole can form a high-quality weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 is a schematic structural diagram of a battery cell structure provided by an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of a first structure of a switching plate structure and a pole provided by an embodiment of the present invention;

[0041] Figure 3 yes Figure 2 A schematic structural diagram of the adapter structure shown;

[0042] Figure 4 is a schematic diagram of a second structure of a switching plate structure and a pole provided in an embodiment of the present invention;

[0043] Figure 5 It is a third structural schematic diagram of a pole connecting portion and a pole provided by an embodiment of the present invention;

[0044] Figure 6 yes Figure 5 A is a partial enlarged schematic diagram;

[0045] Figure 7 This is a first flow chart of an assembly process method of a battery cell structure provided by an embodiment of the present invention;

[0046] Figure 8 This is a second flow chart of the assembly process method of the battery cell structure provided by the embodiment of the present invention.

[0047] Description of reference numerals:

[0048] 100. Cell structure

[0049] 10. Adapter structure;

[0050] 1. a lug connection portion, 11. a main body, 12. a connecting arm;

[0051] 2. Pole connection portion, 21. First side, 211. Cleaning area, 2111. Welding area, 2112. Ring area;

[0052] 31, groove, 32, protrusion;

[0053] 20, battery cell, 201, tab, 202, first tab, 203, second tab;

[0054] 30. Cover plate, 301. Pole. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the drawings; while "inside" and "outside" refer to the outline of the device.

[0056] The battery cell structure usually includes a cover plate and an adapter plate structure. The cover plate is provided with a pole. The pole and the adapter plate structure are usually welded and fixed. However, due to the adhesion of foreign matter or the existence of an oxide layer in the welding area of ​​the adapter plate structure, defects will occur in the welding of the adapter plate structure and the pole.

[0057] In view of this, the present invention proposes an assembly process method for a battery cell structure. Figure 1 is a schematic diagram of a battery cell structure provided by an embodiment of the present invention, Figure 2 is a schematic diagram of a first structure of a switching plate structure and a pole provided in an embodiment of the present invention, Figure 3 yes Figure 2 The schematic diagram of the structure of the adapter structure shown in FIG. Figure 4 is a schematic diagram of a second structure of a switching plate structure and a pole provided in an embodiment of the present invention, Figure 5 1 is a third structural schematic diagram of a pole connection portion and a pole provided by an embodiment of the present invention, Figure 6 yes Figure 5 A is a partial enlarged schematic diagram. Figure 7 This is a first flow chart of an assembly process method of a battery cell structure provided by an embodiment of the present invention. Figure 8 This is a second flow chart of the assembly process method of the battery cell structure provided by the embodiment of the present invention. The battery cell structure, its assembly process method and large energy storage battery provided by the present invention can avoid defects in the adapter structure and pole welding. The battery cell structure will be described in detail in conjunction with the main drawings.

[0058] Reference Figures 1 to 3 The battery cell structure includes a cover plate and two adapter plate structures, the cover plate is provided with two poles arranged at intervals along the Y direction, and two adapter plate structures, each adapter plate structure includes a pole connecting part, the pole connecting part has a first side, the first side has a cleaning area for cleaning, the cleaning area includes a welding area and an annular area surrounding the welding area, wherein the welding area is used to weld and fix the pole connecting part to the pole.

[0059] In an embodiment of the present invention, since the pole connection part 2 is welded and fixed to the pole 301 of the cover plate 30, the stability and reliability of the battery cell structure as a whole are improved, and it is helpful to resist the influence of external factors such as vibration and impact on the connection between the pole connection part and the cover plate. The first side 21 has a clean area 211 for cleaning, and the clean area 211 includes a welding area 2111 and an annular area 2112 surrounding the welding area 2111. This design is intended to ensure that the welding area 2111 is in a clean state before welding, avoiding welding defects caused by impurities, oxides, etc., thereby improving the strength and reliability of the welding between the pole connection part 2 and the pole 301. A clean welding surface helps to reduce the problem of poor contact caused by factors such as corrosion and oxidation, thereby extending the service life of the battery cell structure. In addition, the presence of the annular area 2112 surrounding the welding area 2111 helps to prevent external contaminants from invading the welding area 2111 during welding or connection, thereby improving the purity and stability of the connection, and ensuring that the pole connection part 2 and the pole 301 can form a high-quality weld.

[0060] Reference Figures 2 to 4 In one embodiment, the distance between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112 is L, where L≥1.0mm. In this way, the distance between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112 is greater than or equal to 1.0mm, which provides a larger tolerance for the welding operation. During the welding process, even if there is a slight offset or fluctuation, as long as the offset is within the distance range between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112, it can be ensured that the welding operation falls completely within the clean area, thereby avoiding poor welding or incomplete welding, and improving the overall quality of welding. During the welding process, a large amount of heat will be generated. The distance between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112 is greater than or equal to 1.0mm, which can serve as a heat buffer, help disperse and alleviate the concentrated heat generated in the welding area 2111, and reduce the impact of thermal stress on welding quality, which helps to improve the thermal stability and durability of the welded joint. The distance between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112 is greater than or equal to 1.0 mm, which makes it easier to control the size and shape of the welding area 2111 and the annular area 2112 during the processing, reducing the processing difficulty and cost. At the same time, in the subsequent maintenance process, the design that the distance between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112 is greater than or equal to 1.0 mm also makes it easier to clean and inspect the first side, reducing the complexity and cost of maintenance. When the distance between the boundary of the welding area 2111 and the outer circle boundary of the annular area 2112 is large enough (L≥1.0 mm), the contaminants around the welding area 2111 can be more effectively isolated and removed, ensuring that the welding area 2111 meets the high cleanliness standard before welding. In this way, a purer and more stable welding interface can be obtained during laser welding, thereby improving the quality and strength of the welded joint.

[0061] In addition, when the distance between the boundary of the welding area 2111 and the outer boundary of the annular area 2112 is less than 1 mm, extremely high precision is required during laser welding to control the welding position and ensure that the welding point completely falls within the welding area 2111. This almost reaches the operating requirements at the micron level, posing extremely high challenges to the equipment precision and the technical level of the operators. When the distance between the boundary of the welding area 2111 and the outer boundary of the annular area 2112 is less than 1 mm, it will be almost impossible to accommodate and isolate any impurities or contaminants around the welding area 2111 between the boundary of the welding area 2111 and the outer boundary of the annular area 2112. Even with strict cleaning treatment, it is very difficult to ensure that the welding area 2111 meets the ideal cleanliness standard before welding. Minute factors such as heat and air flow generated during the welding process may have a significant impact on the cleaning effect within such a small distance, resulting in unstable welding quality. The distance between the boundary of the welding area 2111 and the outer boundary of the annular area 2112 being less than 1 mm greatly limits the selection and adjustment range of the welding process, making the process adaptability during production extremely poor.

[0062] It should be noted that the distance between the boundary of the welding area 2111 and the outer boundary of the annular area 2112 can be 1 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.3 mm, or 2.5 mm, etc. Specifically, the distance between the boundary of the welding area 2111 and the outer boundary of the annular area 2112 can be selected as needed, and this application does not make any limitations in this regard.

[0063] In one embodiment, the area of the welding area 2111 is S1, the area of the cleaning area 211 is S2, and the surface area of the first side is S3, where 0 < S1 / S2 < 1; and / or 0 < S2 / S3 ≤ 1. In this way, when S1 / S2 is less than 1, it ensures that the welding area 2111 is completely within the cleaning area 211, making the welding area 2111 in a clean state before welding and avoiding welding defects caused by impurities, oxides, etc. At the same time, S1 / S2 being less than 1 can also protect the welding area 2111 from the influence of contaminants such as impurities and oxides during the welding process. When S2 / S3 is less than or equal to 1, it is achieved that the area of the cleaning area 211 is greater than or equal to the surface area of the first side, which means that the cleaning area 211 almost covers the entire surface area of the first side. In this way, the cleaning area 211 is relatively large, facilitating the welding operation. When 0 < S1 / S2 < 1 and 0 < S2 / S3 ≤ 1, welding operation is achieved while ensuring welding quality and cleanliness.

[0064] It should be noted that S1 / S2 can be 0.1, 0.2, 0.3, 0.35, 0.4, 0.5, 0.54, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 or 0.95 etc. Specifically, the ratio of S1 / S2 can be selected as needed, and the application is not limited to this. In addition, S2 / S3 can be 0.1, 0.15, 0.18, 0.2, 0.25, 0.3, 0.35, 0.4, 0.5, 0.54, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1 etc. Specifically, the ratio of S2 / S3 can be selected as needed, and the application is not limited to this.

[0065] In one embodiment, referring to Figure 5 and Figure 6 , the depth of the cleaning area 211 is H, where 0.5μm≤H≤1000μm. In this way, when the depth of the cleaning area 211 is too shallow and less than 0.5μm, the oxide layer or impurities on the surface of the first side 21 cannot be completely removed, so that the surface roughness of the cleaning area 211 is not enough to achieve the reduction of the diffuse reflection intensity of laser welding, resulting in a large loss of energy, leading to subsequent laser penetration welding and false welding. When the depth of the cleaning area 211 is greater than 1000μm, the surface of the first side 21 will be seriously uneven, and the laser welding defocus amount fluctuates greatly, which is easy to produce welding defects. When the depth of the cleaning area 211 is between 0.5μm and 1000μm, it can be ensured that the oxide layer or impurities on the surface of the first side 21 are completely removed. And the roughness of the surface of the first side 21 can be improved within this depth range to meet the requirements suitable for laser welding. When the surface roughness is moderate, the diffuse reflection intensity of laser welding will be reduced, thereby reducing energy loss and improving welding efficiency and quality. When the depth of the cleaning area 211 is between 0.5 μm and 1000 μm, welding defects caused by insufficient cleaning or excessive cleaning can be avoided. Problems such as cold welding, pores, slag inclusions, etc. can be effectively controlled. When the depth of the cleaning area 211 is between 0.5 μm and 1000 μm, the energy transfer during the welding process can be more stable, reducing the fluctuation of the welding effect caused by the change of the surface state.

[0066] Reference Figure 5In one embodiment, the cleaning area 211 is formed with a groove 31 and a plurality of protrusions 32, and the plurality of grooves 31 and the plurality of protrusions 32 are arranged alternately. In this way, the alternating arrangement of the grooves 31 and the protrusions 32 significantly increases the roughness of the surface of the cleaning area 211. The originally smooth surface becomes uneven after being cleaned, and this change is crucial for laser welding. Because the smooth surface is prone to specular reflection, that is, most of the laser beam is directly reflected back, resulting in a significant reduction in the energy received by the weld. The rough surface is more prone to diffuse reflection, that is, the laser beam is scattered on the surface, increasing the contact area and contact time with the weld, thereby improving the energy absorption efficiency. This diffuse reflection phenomenon enables the laser energy to be more evenly distributed in the welding area 2111, reducing the energy loss caused by reflection. Most of the laser energy can be effectively absorbed by the weld and converted into heat energy for melting the metal, thereby achieving high-quality welding. After the grooves 31 and protrusions 32 are formed in the cleaning area 211, the weld can receive enough energy to melt the metal and form a strong metallurgical bond due to the reduced energy loss and more uniform distribution. Therefore, this design helps to reduce the risk of cold welds and improve the strength and reliability of welded joints.

[0067] Continue to refer to Figure 1 In one embodiment, the battery cell structure 100 further includes two battery cells 20, and the two battery cells 20 are arranged at intervals along the X direction, so as to help the heat dissipation of the battery cells 20. Each battery cell 20 has a first pole ear 202 and a second pole ear 203 arranged at intervals along the Y direction, the two first pole ears 202 of the two battery cells 20 are opposite to each other, and the two second pole ears 203 of the two battery cells 20 are opposite to each other. Each adapter sheet structure 10 further includes a pole ear connection portion 1, which is connected to the pole column connection portion 2. One of the pole ear connection portions 1 of the two adapter sheet structures 10 is connected to the two first pole ears 202 arranged in the opposite position, and the pole ear connection portion 1 of the other of the two adapter sheet structures 10 is connected to the two second pole ears 203 arranged in the opposite position. In this way, the two adapter sheet structures 10 are responsible for connecting the two first pole ears 202 and the two second pole ears 203 in the opposite position, respectively, ensuring the separate transmission of current and avoiding the risk of short circuit. The spacing arrangement of the battery cells 20 and the ingenious design of the adapter structure 10 make the overall structure of the battery cells 20 more stable, which is conducive to reducing the deformation and stress concentration of the battery cells 20 during the charging and discharging process. The current is transmitted to different poles 301 through the adapter structure 10, avoiding the risk of short circuit and improving the safety of the battery cells 20.

[0068] Reference Figures 2 to 4In one embodiment, the tab connection part 1 includes a main body 11 and two connecting arms 12, the main body 11 is connected to the pole connection part 2, the two connecting arms 12 are arranged oppositely and at intervals, one end of the two connecting arms 12 is connected to the main body 11, one of the two connecting arms 12 and / or the main body 11 is used to connect to one of the two tabs 201 arranged in a position between the two battery cells 20, and the other of the two connecting arms 12 and / or the main body 11 is used to connect to the other of the two tabs 201 arranged in a position between the two battery cells 20. In this way, the main body 11, as the core component of the entire tab connection part 1, undertakes the task of connecting with the pole connection part 2 to ensure that the current can be smoothly transmitted to various parts of the energy storage battery. The two connecting arms 12 are arranged oppositely and at intervals. This design not only ensures the stability of the connection, but also enables the connecting arm 12 to be flexibly connected to the tab 201 of the adjacent battery cell 20. One end of the connecting arm 12 is connected to the main body 11 to form a stable support structure. Each connecting arm 12 and the main body 11 are designed to be connected to a specific pole ear 201 of an adjacent battery cell 20. This alignment connection method not only simplifies the connection process, but also improves the accuracy and reliability of the connection. When the energy storage battery is working, the current enters the main body 11 through the pole connection part 2, and then flows to the pole ear 201 of the adjacent battery cell 20 through the two connecting arms 12 respectively, thereby realizing the effective transmission of the current. Since the two connecting arms 12 are arranged oppositely and at intervals and are closely connected to the main body 11, this design greatly enhances the stability of the connection. Even in harsh environments such as vibration or impact, the firmness of the connection can be maintained. The alignment connection method enables the current to be directly and efficiently transmitted to the pole ear 201 of the adjacent battery cell 20, reducing the loss of energy during the transmission process. When the battery cell 20 needs to be maintained or replaced, it can be easily operated by simply disconnecting the connection between the corresponding connecting arm 12 and the pole ear 201. This modular design simplifies the maintenance process and reduces maintenance costs and time.

[0069] It should be noted that, in one embodiment, the two connecting arms 12 may be used to connect to the two pole tabs 201 arranged in alignment with the two battery cells 20, so that the connection operation between the pole tabs 201 and the connecting arms 12 is simple. In another embodiment, the other of the two connecting arms 12 and the main body 11 are used to connect to one of the two pole tabs 201 arranged in alignment with the two battery cells 20, and the other of the two connecting arms 12 and the main body 11 are used to connect to the other of the two pole tabs 201 arranged in alignment with the two battery cells 20, so that the pole tab 201 is firmly connected to the pole tab connecting portion 1. In other embodiments, the main body 11 may also be connected to the two pole tabs 201 arranged in alignment with the two battery cells 20, respectively. Specifically, the method of connecting the pole tab connecting portion 1 with the pole tab 201 can be selected as needed in this application, and this application does not limit this.

[0070] In one embodiment, the area of ​​the cleaning area 211 is S2, the main body 11 has a second side on the same side as the first side, the surface area of ​​the second side is S4, and the surface area of ​​the first side is S3, wherein S3+S4>S2, so that the surface of the first side and the surface of the second side are not completely cleaned, so that the waste of resources and cost are avoided while ensuring the cleaning effect. Since it is only necessary to ensure that the welding area 2111 is in a clean state, however, when S3+S4=S2, it will result in the need to completely clean the surface of the first side and the surface of the second side, which will result in the problem of waste of resources and increase production costs.

[0071] Reference Figure 7 In a second aspect, the present application further provides an assembly process method for the above-mentioned battery cell structure, the assembly process method comprising the following steps:

[0072] Step S100: Obtain two adapter plate structures 10, each adapter plate structure 10 includes a pole connecting portion 2 (refer to Figure 2 ), the pole connecting portion 2 has a first side, and the first side 21 is cleaned to form a cleaning area 211 on the first side 21, and the cleaning area 211 includes a welding area 2111 and an annular area 2112 surrounding the welding area 2111.

[0073] It should be noted that in this step, refer to Figure 6 , the first side 21 refers to the side of the pole connection part 2 away from the pole 301. In addition, the main purpose of the cleaning process is to remove impurities, oil stains, oxides or other substances that may affect the connection quality on the surface of the first side 21 of the pole connection part 2. These impurities may reduce the conductivity of the connection, increase the contact resistance, and even cause the connection to fail. Through the cleaning process, a specific cleaning area 211 is formed on the first side 21 of the pole connection part 2. This area includes not only the welding area 2111 directly involved in welding or connection, but also the annular area 2112 surrounding the welding area 2111. The presence of the annular area 2112 helps to prevent external contaminants from invading the welding area 2111 during welding or connection, thereby improving the purity and stability of the connection. The formation of the cleaning area 211 provides a good foundation for subsequent welding or connection operations. The cleaning of the welding area 2111 ensures that the welding material (such as solder, solder, etc.) can be fully and evenly attached between the pole 301 and the connection component, thereby forming a good welded joint. The presence of the annular area 2112 further enhances the protective barrier of the welded joint. The pole connection portion 2 after cleaning can form a high-quality welding or connection joint, reducing problems such as poor contact and increased resistance caused by impurities, oil stains, etc., thereby improving the stability and reliability of the entire battery cell structure 100.

[0074] There are many shapes of the welding area 2111 and the annular area 2112 surrounding the welding area 2111. For example, Figure 4 In one embodiment, the shape of the welding area 2111 is circular, and the shape of the annular area 2112 is annular. Figure 5 In another embodiment, the shape of the welding area 2111 is a rectangle, and the shape of the annular area 2112 is a square ring. Of course, in another embodiment, the shape of the welding area 2111 is a circle, and the shape of the annular area 2112 is a square ring. Of course, in other embodiments, the shape of the welding area 2111 can also be an irregular shape, and similarly, the shape of the annular area 2112 can be an irregular ring. Specifically, the shapes of the welding area 2111 and the annular area 2112 can be set as needed, and this application does not limit this.

[0075] Step S400, obtain a cover plate 30, the cover plate 30 is provided with two poles 301 arranged at intervals along the Y direction, and the two poles 301 are respectively welded and fixed to the corresponding pole connecting parts 2 at two welding areas 2111 (refer to Figure 3 ).

[0076] It should be noted that in this step, the pole connection portion 2 of the adapter structure 10 is designed with a welding area 2111 for welding and fixing with the pole 301 on the cover plate 30. Welding is a permanent connection method that melts and fuses two metal parts together at high temperature to form a strong mechanical and electrical connection. Welding connection has a higher connection strength than other connection methods (such as crimping, riveting, etc.). By welding and fixing the pole 301 and the pole connection portion 2, it can be ensured that the battery structure 100 maintains a stable connection state during long-term use, reducing failures caused by loose or falling connections. The two poles 301 arranged at intervals along the Y direction can ensure that the current is evenly distributed inside the energy storage battery, reducing current concentration and local overheating. At the same time, the welding connection has a lower contact resistance, which can reduce energy loss and improve the electrical efficiency of the energy storage battery. The welding connection not only realizes the electrical connection, but also enhances the structural strength of the battery structure 100. This connection method can resist the influence of external factors such as vibration and impact, and ensure that the battery structure 100 can still work normally in harsh environments.

[0077] In an embodiment of the present invention, the cleaning area 211 formed after the first side 21 of the pole connection part 2 is cleaned includes a welding area 2111 and an annular area 2112 surrounding the welding area 2111. This design is intended to ensure that the welding area 2111 is in a clean state before welding, avoiding welding defects caused by impurities, oxides, etc., thereby improving the strength and reliability of welding between the pole connection part 2 and the pole 301. A clean welding surface helps to reduce the problem of poor contact caused by factors such as corrosion and oxidation, thereby extending the service life of the battery cell structure 100. In addition, the presence of the annular area 2112 helps to prevent external contaminants from invading the welding area 2111 during welding or connection, thereby improving the purity and stability of the connection. And the presence of the annular area 2112 further enhances the protective barrier of the welded joint. The cleaned welding area 2111 provides a good foundation for subsequent welding or connection operations, ensuring that welding materials (such as solder, solder, etc.) can be fully and evenly attached between the pole 301 and the connection component, thereby forming a good welded joint. After cleaning, the welding area of ​​the pole connection part 2 is free of foreign matter or oxide layer, ensuring uniform heat absorption and conduction during the welding process and enabling high-quality welding between the pole connection part 2 and the pole 301, thereby improving the stability and reliability of the entire battery structure 100. The two poles 301 arranged at intervals along the Y direction can ensure that the current is evenly distributed inside the large energy storage battery, reducing current concentration and local overheating. At the same time, the welding connection has a lower contact resistance, which can reduce energy loss and improve the electrical efficiency of the large energy storage battery.

[0078] In one embodiment, step S100 obtains two adapter plate structures 10, each adapter plate structure 10 includes a pole connecting portion, the pole connecting portion 2 has a first side, and the first side 21 is cleaned to form a clean area 211 on the first side 21, and the clean area 211 includes a welding area 2111 and an annular area 2112 surrounding the welding area 2111. The steps include:

[0079] Step S110 , emitting laser light under preset conditions by a laser device to clean the first side 21 of the pole connecting portion 2 .

[0080] It should be noted that during the laser cleaning process, the laser beam irradiates the surface of the pole connection part 2, and its high energy causes the surface contaminants (such as oxides, grease, dust, etc.) to quickly absorb energy and heat up. When the temperature reaches the boiling point or decomposition point of the contaminant, the contaminant will vaporize, decompose or burn, and thus be removed from the surface. In order to ensure the cleaning effect, the laser equipment needs to set appropriate parameters according to the specific material and contaminant type, such as laser power, spot size, scanning speed, pulse frequency, etc. These preset conditions achieve precise cleaning effects by adjusting the energy distribution and action time of the laser beam.

[0081] In addition, the cleaning process removes pollutants on the surface of the pole connection part 2 and improves the cleanliness of the welding area 2111. The laser cleaning process improves the laser penetration welding quality of the adapter, reduces the welding defects of the adapter, and the laser cleaning process makes the smooth surface of the adapter rough. The mirror reflection in the laser welding process becomes diffuse reflection, the energy loss is reduced, the welding cold welding is reduced, and the welding reliability is improved. The laser cleaning pretreatment of the welding area removes the oxide layer on the surface of the adapter to ensure uniform heat absorption and conduction during the welding process. Laser cleaning treatment helps to reduce defects such as pores and inclusions in the welding process, improve the mechanical properties and electrical properties of the weld, and thus improve the overall welding quality. Through laser cleaning, pollutants that may cause corrosion or poor electrical contact are removed, the failure rate of the pole connection part 2 in the subsequent use process is reduced, and the service life of the battery structure 100 is extended. Laser cleaning is fast and efficient, and can complete large-area cleaning work in a short time. No chemical cleaning agent or a large amount of water resources are required during laser cleaning, which reduces environmental pollution and wastewater discharge. At the same time, laser equipment has high energy efficiency and relatively low energy consumption, which is in line with the green manufacturing concept of modern industry.

[0082] In one embodiment, the laser power is P, wherein the preset conditions include: 100W≤P≤700W. During the laser cleaning process, the laser power directly determines the energy density irradiated to the surface of the material. The higher the energy density, the more heat is transferred to the material per unit time, which leads to an increase in the surface temperature of the material, and the speed and depth of the removal of pollutants also increase accordingly. The laser power in the range of 100W to 700W can effectively remove the oxide layer on the surface of the adapter, ensure uniform heat absorption and conduction during the welding process, and can also roughen the surface of the first side 21, so that the mirror reflection in the laser welding process becomes diffuse reflection, energy loss is reduced, welding false welding is reduced, and welding reliability is improved. When the laser power is low (<100W), due to insufficient energy density, the cleaning depth is limited (<0.5μm), so that the oxide layer on the surface of the first side 21 is not removed, and the surface roughness of the first side 21 is not enough to achieve the laser welding diffuse reflection intensity reduction, resulting in most of the energy loss, resulting in subsequent laser penetration welding false welding. When the laser power is high (>700W), the energy density increases significantly and the cleaning depth is much greater than 1000μm. Although it can quickly heat and remove contaminants deep on the surface of the material, it may cause the surface of the first side 21 to be seriously uneven, and the laser welding defocus amount fluctuates greatly, which is prone to welding defects.

[0083] In one embodiment, the laser frequency is f, wherein the preset conditions include: 100 Hz ≤ f ≤ 800 Hz, so that the laser frequency determines the number of laser pulses per unit time, that is, the density of the cleaning points. The higher the frequency, the more cleaning points are generated per unit time, and the greater the density of the cleaning points. The laser frequency can be effectively removed from the surface oxide layer of the adapter within the range of 100 Hz to 800 Hz to ensure uniform heat absorption and conduction during the welding process. In addition, the surface of the first side 21 can be roughened, so that the mirror reflection during the laser welding process becomes diffuse reflection, energy loss is reduced, welding cold welding is reduced, and welding reliability is improved. When the frequency is lower than 100 Hz, the density of the cleaning points is significantly reduced, resulting in an increase in the spacing between the cleaning points, and the entire cleaning area 211 may not be effectively covered, resulting in partial cleaning. When the frequency is higher than 800 Hz, the density of the cleaning points is too high, and adjacent cleaning points may overlap, resulting in a local area being irradiated by multiple laser pulses, thereby producing an uneven cleaning effect. The cleaning depth is not only affected by the laser power, but also by the regulation of the laser frequency. Although high-frequency laser pulses can increase the density of cleaning points, they may also cause local areas to be over-cleaned due to multiple irradiations, and the cleaning depth may exceed expectations (such as > 1000μm). In this way, although it can quickly heat and remove contaminants deep on the surface of the material, it may cause the surface of the first side 21 to be seriously uneven, and the laser welding defocus amount fluctuates greatly, which is easy to cause welding defects. On the contrary, low-frequency laser pulses may not be able to reach a sufficient cleaning depth due to the low cleaning point density, so that the oxide layer on the surface of the first side 21 is not removed, and the surface roughness of the first side 21 is not enough to achieve the reduction of the diffuse reflection intensity of laser welding, resulting in a large loss of energy, resulting in subsequent laser penetration welding faults.

[0084] In one embodiment, the laser scanning speed is V, wherein the preset conditions include: 500mm / s≤V≤20000mm / s, so that the scanning speed V directly determines the area that the laser can cover per unit time. The faster the speed, the larger the material area processed per unit time, thereby improving production efficiency. The laser scanning speed in the range of 500mm / s to 20000mm / s helps to maintain the stability and uniformity of the laser energy, thereby achieving high-quality cleaning or welding effects. In addition, the oxide layer on the surface of the adapter can be effectively removed to ensure uniform heat absorption and conduction during the welding process. In addition, the surface of the first side 21 can be roughened, so that the mirror reflection in the laser welding process becomes diffuse reflection, energy loss is reduced, welding false welding is reduced, and welding reliability is improved. When the scanning speed is lower than 500mm / s, due to the slow processing speed, the welding cycle (or cleaning cycle) will be correspondingly extended, resulting in a decrease in production capacity. When the scanning speed is too fast (more than 20000mm / s), the laser beam stays on the material surface for a very short time, which may cause the laser energy to fail to fully act on the material surface, resulting in energy instability and uneven cleaning. When the scanning speed is lower than 500 mm / s, the production efficiency drops significantly, affecting the production capacity.

[0085] Reference Figure 8 In one embodiment, each adapter plate structure 10 further includes a pole ear connection portion 1, the pole ear connection portion 1 is connected to the pole column connection portion 2, step S400 obtains a cover plate 30, the cover plate 30 is provided with two poles 301 arranged at intervals along the Y direction, and before the step of respectively welding and fixing the two poles 301 to the corresponding pole column connection portion 2 in the two welding areas 2111, it also includes:

[0086] Step S200, obtain two battery cells 20, each of which has a first electrode tab 202 and a second electrode tab 203 arranged in a spaced relationship along the Y direction, and arrange the two battery cells 20 in a spaced relationship along the X direction (refer to Figure 3 ), and the two first pole tabs 202 of the two battery cells 20 are opposite to each other, and the two second pole tabs 203 of the two battery cells 20 are opposite to each other;

[0087] It should be noted that the shapes of the first electrode tab 202 and the second electrode tab 203 may be the same or different. The shapes of the first electrode tab 202 and the second electrode tab 203 may be set as required, and this application does not limit this.

[0088] Step S300 , connecting the tab connection portion 1 of one of the two adapter structures 10 to the two first tabs 202 arranged in opposite positions, and connecting the tab connection portion 1 of the other of the two adapter structures 10 to the two second tabs 203 arranged in opposite positions.

[0089] In this step, there are many ways to connect the pole ear connection portion 1 of one of the two adapter plate structures 10 to the two first pole ears 202 arranged in the opposite position. For example, the pole ear connection portion 1 of one of the two adapter plate structures 10 and the two first pole ears 202 arranged in the opposite position can be connected by a pin connection, a bolt connection or welding, etc. Specifically, the connection method between the pole ear connection portion 1 of one of the two adapter plate structures 10 and the two first pole ears 202 arranged in the opposite position can be selected as needed, and the present application does not limit this. There are many ways to connect the pole ear connection portion 1 of the other of the two adapter plate structures 10 to the two second pole ears 203 arranged in the opposite position. For example, the pole ear connection portion 1 of the other of the two adapter plate structures 10 and the two second pole ears 203 arranged in the opposite position can be connected by a pin connection, a bolt connection or welding, etc. Specifically, the connection method between the pole ear connection portion 1 of the other of the two adapter plate structures 10 and the two second pole ears 203 arranged in the opposite position can be selected as needed, and the present application does not limit this.

[0090] In one embodiment, step S400 obtains a cover plate 30, the cover plate 30 is provided with two poles 301 arranged at intervals along the Y direction, and the steps of welding and fixing the two poles 301 to the corresponding pole connecting parts 2 at two welding areas 2111 include:

[0091] Step S410 : Penetrate one of the two adapter plate structures 10 through a laser in one of the two welding regions 2111 , so that one of the two adapter plate structures 10 is welded and fixed to one of the two poles 301 .

[0092] In this step, in this step, the laser beam is used to penetrate the adapter structure 10 so that it is welded and fixed to the pole 301, which can ensure the firm connection between the adapter structure 10 and the pole 301, while maintaining the compactness of the structure and the reliability of the electrical connection. In addition, the generation of welding defects such as pores and cracks can be reduced. The two poles 301 on the cover plate 30 are arranged at intervals along the Y direction, which helps to avoid mutual interference during the welding process and improve the accuracy and efficiency of welding. Performing welding operations separately in the two welding areas 2111 can ensure that each welding point can obtain sufficient energy input and precise control, thereby improving the welding quality. Due to the concentrated energy of laser welding, the thermal stress acting on the material is relatively small, which reduces the deformation of the adapter structure 10 during welding and maintains the dimensional accuracy and flatness of the adapter structure 10.

[0093] In one embodiment, step S400 obtains a cover plate 30, the cover plate 30 is provided with two poles 301 arranged at intervals along the Y direction, and the steps of welding and fixing the two poles 301 to the corresponding pole connecting parts 2 at two welding areas 2111 include:

[0094] Step S420 : Penetrate the other one of the two adapter structures 10 by laser at the other one of the two welding regions 2111 , so that the other one of the two adapter structures 10 is welded and fixed to the other one of the two poles 301 .

[0095] In this step, laser welding is an efficient and precise welding method that uses a high-energy-density laser beam as a heat source. In this step, a laser beam is used to penetrate the adapter structure 10 so that it is welded and fixed to the pole 301, which can ensure a firm connection between the adapter structure 10 and the pole 301 while maintaining the compactness of the structure and the reliability of the electrical connection. In addition, the generation of welding defects such as pores and cracks can be reduced. The two poles 301 on the cover plate 30 are arranged at intervals along the Y direction, which helps to avoid mutual interference during the welding process and improve the accuracy and efficiency of welding. Performing welding operations in two welding areas 2111 separately can ensure that each welding point can obtain sufficient energy input and precise control, thereby improving the welding quality. Due to the concentrated energy of laser welding, the thermal stress acting on the material is relatively small, which reduces the deformation of the adapter structure 10 during welding and maintains the dimensional accuracy and flatness of the adapter structure 10.

[0096] An embodiment of the present invention further proposes a large energy storage battery, which includes a battery cell structure 100 assembled by the above-mentioned battery cell structure assembly process method. The specific structure of the battery cell structure 100 refers to the above-mentioned embodiment. Since the large energy storage battery adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0097] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A battery cell structure, characterized in that: Comprising: A cover plate, two pole columns are arranged on the cover plate at intervals along the Y direction; Two adapter plate structures, each of the adapter plate structures includes a pole column connection part, the pole column connection part has a first side, the first side has a cleaning area for being cleaned, the cleaning area includes a welding area and an annular area surrounding the periphery of the welding area, wherein, in the welding area, the pole column connection part is welded and fixed to the pole column.

2. The battery cell structure according to claim 1, characterized in that: The distance between the boundary of the welding area and the outer boundary of the annular area is L, where L≥1.0 mm; and / or, The area of the welding area is S1, the area of the cleaning area is S2, and the surface area of the first side is S3, where 0 < S1 / S2 < 1; and / or 0 < S2 / S3 ≤ 1; and / or, The depth of the cleaning area is H, where 0.5 μm ≤ H ≤ 1000 μm.

3. The battery core structure according to claim 1 or 2, characterized in that: The cleaning area is formed with a plurality of grooves and a plurality of protrusions, and the plurality of grooves and the plurality of protrusions are arranged alternately.

4. The battery core structure according to claim 1 or 2, characterized in that: It further includes two battery cells, the two battery cells are arranged at intervals along the X direction, each of the battery cells has a first tab and a second tab arranged at intervals along the Y direction, the two first tabs of the two battery cells are opposite to each other, and the two second tabs of the two battery cells are opposite to each other; Each of the adapter plate structures further includes a tab connection part, the tab connection part is connected to the pole column connection part, one of the tab connection parts in the two adapter plate structures is connected to the two first tabs arranged in a pairwise manner, and the other tab connection part in the two adapter plate structures is connected to the two second tabs arranged in a pairwise manner.

5. An assembly process method of a battery core structure according to any one of claims 1 to 4, characterized in that: Including the following steps; Obtain two adapter plate structures, each of the adapter plate structures includes a pole column connection part, the pole column connection part has a first side, clean the first side to form a cleaning area on the first side, the cleaning area includes a welding area and an annular area surrounding the periphery of the welding area; Obtain a cover plate, two pole columns are arranged on the cover plate at intervals along the Y direction, and weld the two pole columns to the corresponding pole column connection parts respectively in the two welding areas.

6. The assembly process of the battery core structure according to claim 5, characterized in that: The step of obtaining two adapter plate structures, each of the adapter plate structures includes a pole column connection part, the pole column connection part has a first side, and cleaning the first side to form a cleaning area on the first side, the cleaning area includes a welding area and an annular area surrounding the periphery of the welding area includes: Using a laser device to emit laser under preset conditions to clean the first side of the pole column connection part.

7. The assembly process of the battery core structure according to claim 6, characterized in that: The laser power is P, where the preset conditions include: 100 W ≤ P ≤ 700 W; and / or, The laser frequency is f, where the preset conditions include: 100 Hz ≤ f ≤ 800 Hz; and / or, The laser scanning speed is V, where the preset conditions include: 500 mm / s ≤ V ≤ 20000 mm / s.

8. The assembly process of the battery core structure according to claim 5, characterized in that: Each of the adapter plate structures further includes a pole ear connection portion, the pole ear connection portion is connected to the pole column connection portion, the acquisition cover plate is provided with two poles arranged at intervals along the Y direction, and before the step of respectively welding and fixing the two poles to the corresponding pole column connection portions in the two welding areas, it also includes: Obtain two battery cells, each of which has a first pole ear and a second pole ear arranged at intervals along the Y direction, and arrange the two battery cells at intervals along the X direction, so that the two first pole ears of the two battery cells are opposite to each other, and the two second pole ears of the two battery cells are opposite to each other; The tab connection portion of one of the two adapter structures is connected to the two first tabs arranged in opposite positions, and the tab connection portion of the other of the two adapter structures is connected to the two second tabs arranged in opposite positions.

9. The assembly process of the battery core structure according to claim 5, characterized in that: The step of obtaining a cover plate, wherein the cover plate is provided with two poles spaced apart along the Y direction, and respectively welding and fixing the two poles to the corresponding pole connecting parts at the two welding areas comprises: Penetrating one of the two adapter plate structures by laser in one of the two welding areas, so that one of the two adapter plate structures is welded and fixed to one of the two poles; and / or, The other one of the two welding areas is penetrated by laser into the other one of the two adapter plate structures, so that the other one of the two adapter plate structures is welded and fixed to the other one of the two poles.

10. A large energy storage battery, characterized in that: The invention comprises the battery core structure as claimed in any one of claims 1 to 4.

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