Battery assembly, battery and electric vehicle

Abstract

The application provides a battery assembly, which comprises a pole and a current collecting disc, the current collecting disc comprises a disc body and an electric connecting part, the electric connecting part is formed by extending and protruding from the disc body towards the pole; the pole is provided with a center hole, the electric connecting part is inserted into the center hole, the side wall of the electric connecting part and the inner wall of the center hole are fixed through welding, and the electric connecting part is electrically connected with the pole. The battery assembly provided by the application directly connects the disc body and the pole through the electric connecting part, greatly reduces the internal resistance of the current collecting disc, and thus improves the conductivity of the battery; in addition, the electric connecting part on the current collecting disc does not need to be bent in a "Z" shape, is not prone to cracks, has high assembly efficiency, and is suitable for industrial production requirements. The application further provides a battery and an electric vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery assembly, a battery and an electric vehicle. BACKGROUND

[0002] With the development of electronic technology, lithium ion batteries have been widely used due to their high specific power, long cycle life, good safety performance, and no pollution. In order to improve the single capacity of the battery and reduce the manufacturing cost of the battery, the diameter of the cylindrical battery also begins to gradually increase. In order to meet the charging and discharging and heat dissipation requirements of the large-diameter high-capacity cylindrical battery, the winding core of the cylindrical battery adopts a full-tab design, and the winding core positive and negative tabs are connected to the positive and negative poles of the battery by the positive and negative current collectors. Usually, the positive current collector is connected to the winding core positive tab and the battery positive pole by being bent into a "Z" shape. The bending part of the positive current collector is prone to cracking, and the current path from the battery positive pole to the internal winding core positive tab is long, so the positive current collector has a large internal resistance, which causes the positive current collector to generate more heat during charging and discharging. SUMMARY

[0003] The purpose of the present application is to provide a battery assembly, a battery and an electric vehicle, which aims to solve or at least partially solve the problems existing in the background art. The disc body and the pole are directly connected by the electric connection part, which greatly reduces the internal resistance of the current collector, thereby improving the electrical conductivity of the battery. In addition, the electric connection part on the current collector does not need to be bent into a "Z" shape, which is not prone to cracking and has high assembly efficiency, and is suitable for industrial production requirements.

[0004] One embodiment of the present application provides a battery assembly, comprising a pole and a current collector, wherein the current collector comprises a disc body and an electric connection part, the electric connection part is formed by the disc body extending outwardly towards the pole; the pole is provided with a center hole, the electric connection part is inserted into the center hole, the side wall of the electric connection part and the inner wall of the center hole are fixed by welding, and the electric connection part is electrically connected with the pole.

[0005] In an implementable manner, the side wall of the electric connection part is in contact with the inner wall of the center hole to achieve electrical connection between the electric connection part and the pole. The side wall of the electric connection part is in contact with the inner wall of the center hole, which can achieve electrical connection between the electric connection part and the pole before welding, and the subsequent welding mainly plays a fixing role. The side wall of the electric connection part and the inner wall of the center hole may not be in contact before welding, such as a small gap between them, and the electrical connection and fixing role between the electric connection part and the pole are achieved by subsequent welding.

[0006] In an implementation, the electric connection portion is a hollow circular truncated cone structure with a diameter gradually decreasing in a direction away from the disc body, and the inner wall of the pole is provided with a slope matching the shape of the electric connection portion, and the side wall of the electric connection portion is in contact with the slope.

[0007] In an implementation, the inner wall of the pole is provided with a transverse recess structure near the welded position, and a transverse extension space for increasing the welding space is formed between the transverse recess structure and the side wall of the electric connection portion.

[0008] In an implementation, the transverse extension structure includes a step formed by the inner wall of the pole being concave radially outward.

[0009] In an implementation, the transverse extension structure includes a slope, and the hole diameter of the central hole gradually increases from a side close to the disc to a side away from the disc at the position corresponding to the slope. The slope and the step can be provided simultaneously or separately.

[0010] In an implementation, the side wall of the electric connection portion and the inner wall of the central hole are fixed by laser welding, and the transverse extension space is used to increase the laser incidence angle.

[0011] In an implementation, the laser incidence angle is a, and 0° < a < 180°.

[0012] In an implementation, the pole is a positive pole or a negative pole.

[0013] Another embodiment of the present application also provides a battery including the battery assembly described above.

[0014] Another embodiment of the present application also provides an electric vehicle including the battery described above.

[0015] The battery assembly provided by the application greatly reduces the internal resistance of the current collecting disc by setting the current collecting disc in a structure connected with the disc body and the electric connecting part; meanwhile, by setting the center hole on the pole and inserting the electric connecting part into the center hole, and by fixing the side wall of the electric connecting part and the inner wall of the center hole through welding, the contact area of the current collecting disc and the pole is increased, so that the conductivity of the battery is improved, the heat production of the current collecting disc is reduced, the heat generated in the battery cell can be quickly conducted from the pole, so that the thermal runaway caused by large heat generation of the battery cell during large rate charging and discharging is improved; in addition, the electric connecting part on the current collecting disc does not need to be bent in a "Z" shape, is not prone to cracks, and is convenient for welding and fixing with the pole, has high assembly efficiency, and is suitable for industrial production requirements. Further, in order to solve the welding and fixing problem of the current collecting disc and the pole, a transverse recess structure is additionally arranged on the inner wall of the pole close to the welding position, so that the welding is more convenient and the welding fixing effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a cross-sectional view of the battery assembly in the first embodiment of the application.

[0017] Figure 2 It is a cross-sectional view of the battery assembly in the first embodiment of the application. Figure 1

[0018] Figure 3 It is a cross-sectional view of the battery assembly in the first embodiment of the application. Figure 1

[0019] Figure 4 It is a cross-sectional view of the battery assembly in the first embodiment of the application. Figure 1

[0020] Figure 5 It is a cross-sectional view of the battery assembly in the first embodiment of the application. Figure 1

[0021] Figure 6 It is a cross-sectional view of the battery assembly in the first embodiment of the application.

[0022] Figure 7 It is a cross-sectional view of the battery assembly in the first embodiment of the application.

[0023] Figure 8 It is a cross-sectional view of the battery assembly in the first embodiment of the application. DETAILED DESCRIPTION

[0024] The specific embodiments of the application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the application, but are not used to limit the scope of the application.

[0025] ​​​​The terms “first”, “second”, “third”, “fourth” and the like in the description and claims of the application, if any, are used for distinguishing between similar objects and are not necessarily used to describe a particular sequential or chronological order.

[0026] The orientation terms, such as upper, lower, left, right, front, back, top, bottom and the like, if any, in the description and claims of the application are defined according to the position of the structure in the drawing and the position of the structure relative to each other, only for the purpose of expressing the technical solution clearly and conveniently. It should be understood that the use of orientation terms should not limit the scope of the application claimed.

[0027] As shown in Figures 1 to 5 , the battery assembly provided by the embodiment of the application includes a pole 3 and a current collector plate 6, the current collector plate 6 includes a disc body 61 and an electrical connection part 62, the electrical connection part 62 is formed by extending and protruding from the disc body 61 towards the pole 3. The pole 3 is provided with a center hole 33, the electrical connection part 62 is inserted into the center hole 33, the side wall of the electrical connection part 62 and the inner wall of the center hole 33 are fixed by welding, the electrical connection part 62 is electrically connected with the pole 3, and the disc body 61 is in contact with the end face of the battery cell 8.

[0028] As shown in Figure 1 , as an implementation manner, the side wall of the electrical connection part 62 is in contact with the inner wall of the center hole 33 to realize the electrical connection between the electrical connection part 62 and the pole 3.

[0029] Specifically, by setting the current collector plate 6 as a structure that the disc body 61 and the electrical connection part 62 are connected, the internal resistance of the current collector plate 6 is greatly reduced; at the same time, by setting the center hole 33 on the pole 3 and inserting the electrical connection part 62 into the center hole 33, and fixing the side wall of the electrical connection part 62 and the inner wall of the center hole 33 by welding, the contact area of the current collector plate 6 and the pole 3 is increased, thereby improving the electrical conductivity of the battery, reducing the heat generation of the current collector plate 6, and the heat generated inside the battery cell 8 can be quickly conducted out through the pole 3, thereby improving the thermal runaway caused by the large heat generation of the battery cell 8 during large-rate charging and discharging; in addition, the electrical connection part on the current collector plate 6 does not need to be bent in a “Z” shape, is not prone to cracks, and is convenient for welding and fixing with the pole 3, has high assembly efficiency, and is suitable for industrial production requirements.

[0030] As shown in Figures 3 to 5 , as an implementation manner, the cross section of the electrical connection part 62 is a circular structure, the electrical connection part 62 is a hollow circular truncated cone structure that gradually shrinks in diameter along the direction away from the disc body 61, the inner wall of the pole 3 is provided with a slope 36 matched with the shape of the electrical connection part 62, and the side wall of the electrical connection part 62 is in contact with the slope 36, thereby increasing the contact area of the current collector plate 6 and the pole 3.

[0031] As shown in Figure 6As shown, in another embodiment, the inner wall of the electrode post 3 has a lateral recessed structure near the welding position. This lateral recessed structure and the side wall of the electrical connection portion 62 form a lateral extension space 300 to increase the welding space. The lateral extension structure includes a step 34, which is formed by a radial outward recess from the inner wall of the electrode post 3. The side wall of the electrical connection portion 62 is fixed to the inner wall of the central hole 33 by laser welding. The lateral extension space 300 is used to increase the laser incident angle. The laser incident angle is α, where 0° < α < 180°.

[0032] like Figure 7 As shown, in another embodiment, the lateral extension structure includes a ramp 35, and the diameter of the central hole 33 at the position corresponding to the ramp 35 gradually increases from the side closer to the collector plate 6 toward the side farther away from the collector plate 6.

[0033] like Figure 8 As shown, in another embodiment, the inner wall of the pole post 3 near the welding position is provided with both a step 34 and a ramp 35. Of course, in other embodiments, the above-mentioned lateral recessed structure can also be other structures, as long as it can form a lateral extension space 300 between the lateral recessed structure and the side wall of the electrical connection part 62.

[0034] Specifically, by setting a laterally recessed structure on the inner wall of the electrode post 3 near the welding position, a laterally extending space 300 is formed between the laterally recessed structure and the side wall of the electrical connection part 62. This significantly increases the selectability of the laser incident angle α during the welding process, ensuring the optimal welding angle (e.g., ...). Figure 5 As shown, without a lateral recessed structure, the laser incident angle α is greatly reduced, which is detrimental to the welding operation. Furthermore, when the wall thickness of the electrical connection part 62 is relatively thin, it is easy to burn through when laser welding it to the inner wall of the central hole 33. To solve the problem of burn-through of the electrical connection part 62 during laser welding, a lateral recessed structure (step 34 or ramp 35) can be set to adjust the laser welding position. The welding position can be adjusted to be closer to or further away from the electrical connection part between the collector plate 6 and the pole post 3 (i.e., the part where the side wall of the electrical connection part 62 contacts the inner wall of the central hole 33) according to the actual welding effect, to ensure the best welding effect.

[0035] like Figure 1 and Figure 5 As shown, in one embodiment, the battery assembly also includes a cover plate 2, a current collector 6 located on the side of the cover plate 2 near the cell 8, and a terminal post 3 penetrating the cover plate 2 and fixed to the cover plate 2 by riveting.

[0036] Specifically, in this embodiment, the pole post 3 and the cover plate 2 are fixed by riveting. Compared with the method of fixing the pole post 3 and the cover plate 2 by welding, this not only simplifies the operation and improves production efficiency, but also reduces production costs.

[0037] like Figures 1 to 3 As shown, in one embodiment, the cover plate 2 is provided with a through hole 21. The pole post 3 includes a main body 30A and a first end 30B and a second end 30C located at opposite ends of the main body 30A. The main body 30A is inserted into the through hole 21. The first end 30B and the second end 30C extend outward from the main body 30A in opposite directions from the through hole 21 (in this embodiment, the first end 30B extends upward from the main body 30A, and the second end 30C extends downward from the main body 30A). The cover plate 2, the first end 30B and the second end 30C are riveted together. The part of the cover plate 2 that participates in the riveting is located between the first end 30B and the second end 30C.

[0038] like Figure 1 As shown, in one embodiment, the battery assembly also includes a clamping block 4, which participates in riveting, that is, the clamping block 4, the terminal post 3, and the cover plate 2 are riveted together. The clamping block 4 is disposed at the first end 30B and / or the second end 30C of the terminal post 3. During riveting, the terminal post 3 and the clamping block 4 are fitted together.

[0039] Specifically, in this embodiment, the pressure block 4 can be an aluminum block. Of course, in other embodiments, the pressure block 4 can also be made of other materials.

[0040] like Figure 1 As shown, in one embodiment, the pressure block 4 is disposed at the second end 30C of the pole post 3 (i.e., the pressure block 4 fills the lower end of the pole post 3). Of course, in other embodiments, the pressure block 4 may also be disposed at the first end 30B of the pole post 3, or simultaneously disposed at the first end 30B and the second end 30C of the pole post 3.

[0041] like Figure 1 As shown, in one embodiment, the pressure block 4 has a ring structure and is fitted onto the second end 30C of the pole post 3. Of course, in other embodiments, the pressure block 4 can also be fitted onto the first end 30B of the pole post 3, or simultaneously fitted onto the first end 30B and the second end 30C of the pole post 3.

[0042] like Figure 1As shown, as an embodiment, the pole column 3 is in T-shaped structure, the first end 30B of the pole column 3 is provided with a stopper 31, the stopper 31 is formed by the side wall of the pole column 3 protruding radially outward, and the stopper 31 is located on one side of the cover plate 2; the second end 30C of the pole column 3 is formed with a flange 32, the flange 32 is formed by the side wall of the pole column 3 protruding radially outward, and the flange 32 is located on the other side of the cover plate 2. In the radial direction of the pole column 3, the diameter of the stopper 31 is greater than the diameter of the flange 32. The stopper 31 and the flange 32 are riveted with the cover plate 2, and the part of the cover plate 2 participating in riveting is located between the stopper 31 and the flange 32. Of course, in other embodiments, the second end 30C of the pole column 3 can be provided with the stopper 31, and the first end 30B of the pole column 3 is formed with the flange 32.

[0043] Specifically, in the present embodiment, the stopper 31 is arranged at the top of the pole column 3, the stopper 31 is located above the cover plate 2, and the stopper 31 is located outside the shell 1; the flange 32 is arranged at the bottom of the pole column 3, the flange 32 is located below the cover plate 2, and the flange 32 is located inside the shell 1.

[0044] As shown, Figure 1 As an embodiment, the pressing block 4 is sleeved on the pole column 3 near the flange 32, and the pressing block 4 is located between the flange 32 and the cover plate 2. During riveting, the pressing block 4 is embedded with the flange 32. Of course, in other embodiments, the pressing block 4 can also be sleeved on the pole column 3 near the stopper 31, and at this time, the pressing block 4 is located between the stopper 31 and the cover plate 2.

[0045] Specifically, as shown, Figure 1 and Figure 3 The stopper 31 is a structure that the pole column 3 itself has (i.e. the stopper 31 exists before the pole column 3 and the cover plate 2 are riveted), and the flange 32 is formed when the pole column 3 and the cover plate 2 are riveted (i.e. the flange 32 does not exist before the pole column 3 and the cover plate 2 are riveted). Specifically, as shown, Figure 1 In the present embodiment, when the pole column 3 and the cover plate 2 are riveted, the pole column 3 in T-shaped structure is first inserted into the through hole 21 on the cover plate 2 from top to bottom, and then the lower end of the pole column 3 is mechanically pressed (such as spin riveting) to flatten and form the flange 32; during the process of pressing the lower end of the pole column 3 to flatten and form the flange 32, the pole column 3 is formed to have a upsetting effect (i.e. the length of the pole column 3 is shortened and the diameter is increased), so that the pole column 3 and the cover plate 2 are fixed, thereby realizing the riveting of the pole column 3 and the cover plate 2. The stopper 31 and the flange 32 both have a limiting effect, and the stopper 31 and the flange 32 cooperate to press the cover plate 2 tightly to prevent the pole column 3 from falling out of the through hole 21 on the cover plate 2. At the same time, during the riveting of the pole column 3 and the cover plate 2, the insulating sealing ring 51 is compressed during the formation of the flange 32, so that the gap between the stopper 31 and the cover plate 2 is completely filled with the insulating sealing ring 51, thereby improving the sealing performance of the battery.

[0046] As shown in Figure 1 one embodiment, the battery assembly further comprises an insulating sealing ring 51, which is sleeved on the pole 3 and close to the stopper 31, and is used for insulation and sealing between the pole 3 and the cover plate 2.

[0047] As shown in Figure 1 one embodiment, the insulating sealing ring 51 is at least partially arranged in the through hole 21, and is located between the outer side wall of the pole 3 and the inner wall of the through hole 21.

[0048] Specifically, in the present embodiment, the insulating sealing ring 51 is in a T-shaped structure (of course, in other embodiments, the insulating sealing ring 51 can also be in an O-shaped structure, etc.), and a part of the insulating sealing ring 51 is located in the through hole 21 (i.e., between the outer side wall of the pole 3 and the inner wall of the through hole 21), and the other part is located outside the cover plate 2 and clamped between the stopper 31 and the cover plate 2, so that the insulating sealing ring 51 can have a good sealing effect on the sealing between the pole 3 and the cover plate 2, and can also insulate the pole 3 and the cover plate 2 to prevent the pole 3 and the cover plate 2 from conducting electricity. At the same time, when the pole 3 and the cover plate 2 are riveted, during the process of pressing the pole 3 to upset the pole 3, the stopper 31 will have a pressing effect on the insulating sealing ring 51, so that the insulating sealing ring 51 between the stopper 31 and the cover plate 2 is compressed, thereby further improving the sealing effect.

[0049] As shown in Figure 1 one embodiment, the battery assembly further comprises an insulating ring 52, which is arranged between the stopper 31 and the cover plate 2, and is used for insulating the pole 3 and the cover plate 2 to prevent the pole 3 and the cover plate 2 from conducting electricity.

[0050] Specifically, in the present embodiment, the insulating sealing ring 51 is in a small circular ring structure with a central opening, and the insulating ring 52 is in a large circular ring structure with a central opening, and the insulating ring 52 is arranged around the periphery of the insulating sealing ring 51.

[0051] As shown in Figure 1 one embodiment, the battery assembly further comprises an insulating gasket 53, which is arranged between the pressing block 4 and the cover plate 2.

[0052] Specifically, in the present embodiment, a part of the insulating gasket 53 is located between the pressing block 4 and the cover plate 2, and the other part is located between the current collecting disc 6 and the cover plate 2, thereby preventing the pressing block 4 and the cover plate 2 from conducting electricity, and preventing the current collecting disc 6 and the cover plate 2 from conducting electricity.

[0053] As shown in Figure 1As shown, as an embodiment, the battery assembly further comprises a sealing sheet 9 (the sealing sheet 9 can be an anti-explosion sheet), the sealing sheet 9 is sealingly connected with the top surface of the pole 3, and the sealing sheet 9 seals the center hole 33 on the pole 3.

[0054] As shown in the drawings, Figure 1 As shown, the embodiment of the application further provides a battery, which is especially suitable for a cylindrical battery. The battery comprises the battery assembly and the shell 1 as described above, the shell 1 is a cylindrical groove structure, the top end of the shell 1 is provided with an opening 11, the cover plate 2 is used for sealing the opening 11 of the shell 1, the cover plate 2 is fixed at the opening 11 of the shell 1, and the cover plate 2 is electrically connected with the shell 1. The opposite ends of the pole 3 are respectively located outside the opening 11 of the shell 1 and inside the opening 11 of the shell 1.

[0055] As another embodiment, the top end of the cylindrical battery body is provided with a groove (not shown in the drawings), and the pole 3 is inserted into the groove. In addition, a standard compatible insulating sealing ring can also be sleeved in the groove.

[0056] As shown in the drawings, Figure 1 As an embodiment, the battery further comprises a current collecting component 7 and a cell 8, the current collecting disc 6, the current collecting component 7 and the cell 8 are all arranged in the shell 1, the current collecting disc 6 is located between the top end of the cell 8 and the pole 3, and the two sides of the current collecting disc 6 are respectively electrically connected with the top end of the cell 8 and the pole 3. The current collecting component 7 is located between the bottom end of the cell 8 and the shell 1, and the two sides of the current collecting component 7 are respectively electrically connected with the bottom end of the cell 8 and the shell 1.

[0057] As shown in the drawings, Figure 1 As an embodiment, the two sides of the current collecting disc 6 are respectively in contact with the top end of the cell 8 and the pole 3 to realize electrical connection, and the two sides of the current collecting component 7 are respectively in contact with the bottom end of the cell 8 and the shell 1 to realize electrical connection.

[0058] As shown in the drawings, Figure 1 As an embodiment, the current collecting component 7 is a flat disc structure.

[0059] As shown in the drawings, Figure 1 As an embodiment, the two ends of the cell 8 are respectively provided with a positive electrode lug 81 and a negative electrode lug 82, the pole 3 is a positive pole, the current collecting disc 6 is a positive current collecting disc, the current collecting component 7 is a negative current collecting disc, the two sides of the current collecting disc 6 are respectively in contact with the positive electrode lug 81 of the cell 8 and the pole 3, and the two sides of the current collecting component 7 are respectively in contact with the negative electrode lug 82 of the cell 8 and the bottom wall of the shell 1. Of course, in other embodiments, the pole 3 can be a negative pole, the current collecting disc 6 can be a negative current collecting disc, the current collecting component 7 can be a positive current collecting disc, the two sides of the current collecting disc 6 can be respectively in contact with the negative electrode lug 82 of the cell 8 and the pole 3, and the two sides of the current collecting component 7 can be respectively in contact with the positive electrode lug 81 of the cell 8 and the bottom wall of the shell 1.

[0060] Specifically, when the pole 3 is a positive pole, the shell 1 can be a steel shell (of course, other materials are also possible), at this time the pole 3 serves as a positive electrode connection terminal of the battery, and the shell 1 and the cover plate 2 serve as negative electrode connection terminals of the battery; when the pole 3 is a negative pole, the shell 1 can be an aluminum shell, at this time the pole 3 serves as a negative electrode connection terminal of the battery, and the shell 1 and the cover plate 2 serve as positive electrode connection terminals of the battery. The present embodiment, by taking the pole 3 and the cover plate 2 as positive and negative electrode connection terminals respectively (or taking the pole 3 as a negative electrode connection terminal and the cover plate 2 as a positive electrode connection terminal), leads the positive and negative electrodes of the battery out to the same side of the battery, which is advantageous for the grouping of the battery, can facilitate the arrangement of the battery, reduces the number of structural components when the battery is grouped, simplifies the wiring design of the BMS, reduces the cost, and at the same time makes the arrangement of the battery more compact and improves the energy density of the battery.

[0061] As shown in FIG. 1, the battery assembly provided by the present embodiment comprises a shell 1, a cover plate 2, a plurality of poles 3, a plurality of battery cells 8, a plurality of current collecting plates 6, and a plurality of current collecting components 7. Figure 1 As shown in FIG. 1, the battery assembly provided by the present embodiment comprises a shell 1, a cover plate 2, a plurality of poles 3, a plurality of battery cells 8, a plurality of current collecting plates 6, and a plurality of current collecting components 7.

[0062] As an embodiment, the shell 1 is further provided with an electrolyte solution, so that the battery can be charged and discharged through the electrochemical reaction of the positive and negative plates of the battery cell 8 and the electrolyte solution. The electrolyte solution can be formed by organic solvents such as EC, PC, DEC, EMC and EMC, and lithium salts such as LiPF6 or LiBF4, and the electrolyte can be in a liquid, solid or gel state, etc.

[0063] The battery assembly provided by the present embodiment greatly reduces the internal resistance of the current collecting plate 6 by setting the current collecting plate 6 as a structure in which the disc body 61 and the electrical connection part 62 are connected; at the same time, by setting the central hole 33 on the pole 3 and inserting the electrical connection part 62 into the central hole 33, the contact area of the current collecting plate 6 and the pole 3 is increased, thereby improving the electrical conductivity of the battery and reducing the heat generation of the current collecting plate 6, and the heat generated inside the battery cell 8 can be quickly conducted out through the pole 3, thereby improving the thermal runaway caused by the large heat generation of the battery cell 8 during large-rate charging and discharging; in addition, the electrical connection part on the current collecting plate 6 does not need to be bent in a "Z" shape, is not prone to cracking, and is convenient for welding and fixing with the pole 3, has high assembly efficiency, and is suitable for industrial production needs.

[0064] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery assembly comprising terminals (3) and current collectors (6), characterized in that, The collector plate (6) includes a plate body (61) and an electrical connection part (62). The electrical connection part (62) is formed by the plate body (61) extending and protruding towards the pole post (3). The pole post (3) is provided with a central hole (33). The electrical connection part (62) is inserted into the central hole (33). The side wall of the electrical connection part (62) is fixed to the inner wall of the central hole (33) by welding. The electrical connection part (62) is electrically connected to the pole post (3). The inner wall of the pole post (3) is provided with a lateral recessed structure near the welding position. The lateral recessed structure and the side wall of the electrical connection part (62) form a lateral extension space (300) for increasing the welding space. The lateral recessed structure includes a step (34) formed by a radial outward recess of the inner wall of the pole post (3); and / or, the lateral recessed structure includes a ramp (35) in which the diameter of the central hole (33) at the position corresponding to the ramp (35) gradually increases from the side closer to the collector plate (6) toward the side farther away from the collector plate (6).

2. The battery assembly as claimed in claim 1, characterized in that, The sidewall of the electrical connection part (62) contacts the inner wall of the central hole (33) to achieve electrical connection between the electrical connection part (62) and the pole (3).

3. The battery assembly as described in claim 2, characterized in that, The electrical connection part (62) is a frustum-shaped structure with a gradually decreasing diameter along the direction away from the disk body (61). The inner wall of the pole post (3) is provided with an inclined surface (36) that matches the shape of the electrical connection part (62). The side wall of the electrical connection part (62) is in contact with the inclined surface (36).

4. The battery assembly as claimed in claim 1, characterized in that, The sidewall of the electrical connection part (62) is fixed to the inner wall of the central hole (33) by laser welding, and the lateral extension space (300) is used to increase the laser incident angle.

5. The battery assembly as claimed in claim 4, characterized in that, The laser incident angle is α, where 0° < α < 180°.

6. The battery assembly as described in any one of claims 1-5, characterized in that, The pole (3) is either a positive pole or a negative pole.

7. A battery, characterized in that, Includes the battery assembly as described in any one of claims 1-6.

8. An electric vehicle, characterized in that, Includes the battery as described in claim 7.

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