Novel connecting structure of battery pole group and collector plate and lithium ion battery

Abstract

The utility model discloses a novel connecting structure of a battery pole group and a collector plate. The novel connecting structure comprises the battery pole group and the collector plate, the battery pole group comprises a butterfly-shaped pole lug and a pole group main body, the current collecting disc is positioned right above the pole group main body; two butterfly-shaped tabs are arranged on the pole group main body and are used for connecting the top end of the current collecting plate; the top of the butterfly-shaped tab is in laser welding with the bottom of the collector plate; a boss structure is arranged at the central position of the collector plate; a liquid injection hole is formed in the boss structure; welding area parts are arranged at the left end and the right end of the collector plate respectively; the two welding area parts are connected with the two sides of the bottom end of the boss structure respectively; and the bottom surface of the welding area part is in laser welding with the top of the butterfly-shaped tab. In addition, the utility model also provides a lithium ion battery. The butterfly-shaped tabs are arranged at one end of the battery pole group, when the butterfly-shaped tabs are shaped, the surrounding space is large, the bending directions of the tabs are multiple, the internal wrinkling probability of the tabs is less than that of all-tab shaping, and the safety of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a novel connection structure of a battery pole group and a current collecting plate and a lithium ion battery. Background Art

[0002] The continuous development of lithium-ion battery technology has made it more and more widely used in electric vehicles and other fields. With the continuous expansion of the electric vehicle market and the improvement of people's requirements for electric vehicle performance such as driving range and charging speed, higher requirements are also put forward for the performance of lithium-ion batteries.

[0003] The full-ear structure is the main assembly method for high-power performance batteries. For batteries with a full-ear structure, one end face of the overall battery electrode group is the ear, and the ear is welded to its corresponding circular current collecting plate. This combined structure is applied to cylindrical batteries. On the one hand, it will lead to an increase in the internal space occupancy of the battery, resulting in a decrease in the content of active materials and a reduction in battery capacity.

[0004] In addition, there is an invisible risk to battery safety in the shaping of the full-tab pole group. Since the shaping of the full-tab pole group generally adopts the flattening method, the tabs are pressed inward at the same time, there will be wrinkles inside the tabs, and there is a risk of puncturing the diaphragm.

[0005] On the other hand, the end face of the current collecting plate matched with the full-ear electrode group is larger, and the electrolyte injection hole of the general battery is on the side of the cover plate. When the electrolyte enters, it will first contact the current collecting plate, and then flow in from the side gap, which has an adverse effect on the wetting effect of the electrolyte in a short time, and the wetting quality and efficiency of the electrolyte cannot be guaranteed, resulting in the inability to achieve effective infiltration of the electrolyte. The effective infiltration of the electrolyte has a direct impact on the formation and performance of the battery.

[0006] Therefore, there is an urgent need to develop a technology that can solve the above technical problems. Utility Model Content

[0007] The purpose of the utility model is to provide a new connection structure between a battery pole group and a current collecting plate and a lithium ion battery in view of the technical defects in the prior art.

[0008] To this end, the utility model provides a novel connection structure between a battery pole group and a current collecting plate, which comprises a battery pole group and a current collecting plate;

[0009] A battery pole group, including a butterfly-shaped pole ear and a pole group body;

[0010] The current collecting plate is located directly above the main body of the pole group;

[0011] The top of the pole group body for connecting to the current collecting plate is provided with two butterfly-shaped pole ears;

[0012] The top of the butterfly-shaped pole ear is laser welded to the bottom of the collector plate;

[0013] Wherein, a boss structure is provided at the center of the collecting plate;

[0014] A vertically penetrating injection hole is provided in the boss structure;

[0015] A welding area is provided at the left and right ends of the current collecting plate respectively;

[0016] The two welding areas are centrally symmetrically distributed;

[0017] Two welding area parts are respectively connected to two sides of the bottom end of the boss structure;

[0018] The bottom surface of the welding area is laser welded to the top of the butterfly-shaped pole ear.

[0019] In addition, the utility model also provides a lithium-ion battery, including the novel connection structure of the battery electrode group and the current collecting plate as described above;

[0020] The battery pole group is arranged in the inner cavity of the battery shell.

[0021] It can be seen from the technical solution provided by the utility model above that, compared with the prior art, the utility model provides a new connection structure between a battery pole group and a current collecting plate and a lithium-ion battery, which is scientifically designed. One end of the battery pole group adopted is a butterfly-shaped pole ear. When the butterfly-shaped pole ear is shaped, the surrounding space is large, the pole ear has many bending directions, and the probability of wrinkles inside the pole ear is less than that of the full pole ear shaping, which greatly reduces the risk of wrinkled pole ears piercing the diaphragm, reduces the risk of invisible short circuits, and improves the safety of the battery, which has great practical significance.

[0022] In addition, in the utility model, the central part of the current collecting plate matching the butterfly-shaped pole ear contains a liquid injection hole with a hollow structure, which can effectively improve the infiltration effect of the electrolyte and quickly increase the entry efficiency of the electrolyte.

[0023] In addition, in the present invention, the battery pole group and the current collecting plate are connected by laser welding, which has high reliability and good sealing, and further improves the utilization rate of the battery content space. In addition, the new connection structure of the battery pole group and the current collecting plate provided by the present invention can provide a good welding boss when the monomer is composed of a module, which is conducive to ensuring the effective connection and good product rate of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a novel connection structure between a battery electrode group and a current collecting plate provided by the utility model;

[0025] Figure 2A top view of a novel full-electrode-ear electrode group in a novel connection structure between a battery electrode group and a current collecting plate provided by the utility model;

[0026] Figure 3 A schematic structural diagram of a pole piece of a pole group in a novel connection structure between a battery pole group and a current collecting plate provided by the utility model;

[0027] Figure 4 A schematic structural diagram of a current collecting plate in a novel connection structure between a battery electrode group and a current collecting plate provided by the utility model;

[0028] Figure 5 A cross-sectional view of a current collecting plate, a battery electrode group and a battery shell provided by the utility model;

[0029] In the figure: 1 is a current collecting plate; 2 is a battery electrode group; 3 is a battery housing;

[0030] 21 is a butterfly-shaped pole ear, and 22 is a pole group body. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] See also Figures 1 to 4 , the utility model provides a novel connection structure between a battery pole group and a current collecting plate, comprising a battery pole group 2 and a current collecting plate 1;

[0036] A battery electrode group 2, comprising a butterfly-shaped electrode ear 21 and an electrode group body 22;

[0037] The current collecting plate 1 is located directly above the pole group body 22;

[0038] The top of the pole group body 22 for connecting to the current collecting plate 1 is provided with two butterfly-shaped pole ears 21;

[0039] The top of the butterfly-shaped pole ear 21 is laser welded to the bottom of the current collecting plate 1;

[0040] It should be noted that the butterfly-shaped pole ear 21 is connected to the current collecting plate 1 by laser welding, which ensures sufficient welding area and current carrying capacity, lower internal resistance of the battery, and better power performance. In specific implementation, according to customer needs, two butterfly-shaped pole ears 21 are provided at both ends (top and bottom) of the pole group body 22, and then the positive and negative currents of the pole group are respectively isolated and led out through the corresponding current collecting structure (such as the current collecting plate) (the specific isolation means can adopt the conventional means known in the art, such as isolation rings, etc., which can avoid short circuits caused by contact between the positive and negative poles, and will not be repeated here).

[0041] Wherein, a boss structure is provided at the center of the collecting plate 1;

[0042] A vertically penetrating injection hole 130 is provided in the boss structure;

[0043] A welding area 14 is provided at the left and right ends of the current collecting plate 1;

[0044] The two welding area portions 14 are centrally symmetrically distributed;

[0045] Two welding area portions 14 are respectively connected to two sides of the bottom end of the boss structure (specifically, they can be integrally formed);

[0046] The bottom surface of the welding region 14 is laser welded to the top of the butterfly-shaped tab 21 .

[0047] In the present invention, in a specific implementation, two butterfly-shaped pole ears 21 are provided at the top of the pole group body 22, and the two butterfly-shaped pole ears 21 are positive pole ears;

[0048] Two butterfly-shaped pole ears 21 are arranged at the bottom end of the pole group body 22 , and the two butterfly-shaped pole ears 21 are negative pole ears.

[0049] In the present invention, in specific implementation, the top and bottom surfaces of the butterfly-shaped pole ear 21 are both fan-shaped;

[0050] Furthermore, the shape of the top surface of the butterfly-shaped tab 21 is smaller than the shape of the bottom surface.

[0051] Furthermore, the central angle α of the butterfly-shaped pole ear is 30° to 90°.

[0052] In the present invention, in specific implementation, the pole group body 22 is provided with a central through hole 230 between the two butterfly-shaped pole ears 21;

[0053] Further, the central through hole 230 vertically penetrates through the pole group body 22;

[0054] The central through hole 230 is located directly below the injection hole 130 .

[0055] In the present utility model, in specific implementation, the boss structure of the current collecting plate 1 includes a hollow second boss 12, a first boss 11, a concave platform 16 and a second boss base 13;

[0056] The top of the second boss chassis 13 is provided with a first boss 11;

[0057] A hollow second boss 12 is provided on the top of the first boss 11;

[0058] The inner cavity of the second boss 12 is surrounded by a concave platform 16;

[0059] A liquid injection hole 130 is provided in the concave platform 16;

[0060] Both sides of the second boss chassis 13 are respectively connected to a welding area portion 14 (specifically, they can be integrally formed);

[0061] In a specific implementation, the injection hole 130 vertically penetrates the second boss 12 , the first boss 11 , the concave platform 16 and the second boss base 13 .

[0062] In a specific implementation, the cross-sectional shapes of the second boss 12 , the first boss 11 and the recessed boss 16 are all circular.

[0063] In a specific implementation, the shape of the welding area portion 14 is a butterfly shape, see Figure 4 shown.

[0064] In a specific implementation, the two side edges of the welding area 14 are provided with upwardly protruding, long strip-shaped reinforcing ribs 15;

[0065] The edges of the two welding regions 14 on the opposite sides are in arc shape.

[0066] It should be noted that the welding area portion 14 is butterfly-shaped, and the two welding area portions 14 are centrally symmetrical figures. The edge of the welding area portion 14 is an arc shape, which is an arc of a circular portion concentric with the injection hole 130. The radius of the circular portion corresponding to the arc shape is smaller than the radius of the electrode group body 22, which can ensure that the collecting plate does not contact the cylindrical battery shell.

[0067] In a specific implementation, the center points of the injection hole 130, the second boss 12, the first boss 11 and the concave boss 16 are located on the same central axis;

[0068] In specific implementation, the outer diameters of the concave platform 16, the second convex platform 12 and the first convex platform 11 increase in sequence;

[0069] The vertical heights of the first boss 11, the recessed boss 16 and the second boss 12 increase in sequence.

[0070] It should be noted that the concave platform 16 is lower than the second convex platform 12 to avoid splashing residues during welding of the sealing pins, which affects the overall height, and further avoids the welding being affected by the height difference when the monomers are assembled into modules.

[0071] In a specific implementation, the shape of the injection hole 130 is cylindrical;

[0072] In a specific implementation, the injection hole 130 is a hollow cylindrical through hole, which is located at the center of the collecting plate and is used in conjunction with a rubber plug and a sealing nail in the later stage.

[0073] In a specific implementation, the thickness of the welding area portion 14 is 0.5-1.5 mm;

[0074] The height of the first boss 11 is 0.3-4 mm, and its specific thickness is consistent with the thickness of the shell or cover plate that matches it. The first boss is welded after being matched with the shell or cover plate.

[0075] In a specific implementation, both the end surface on the inner circle of the top end of the second boss 12 and the end surface on the outer circle are chamfered.

[0076] In a specific implementation, for the current collecting plate 1, at least one positioning hole 17 is provided on the welding area portion 14 for positioning welding with the butterfly-shaped pole lug on the battery pole group.

[0077] In the present invention, it should be noted that the butterfly-shaped pole ear 21 is similar in shape to the current collecting plate 1 with the injection hole, and the size of the butterfly-shaped pole ear 21 is larger than the size of the current collecting plate 1 .

[0078] In the present invention, in a specific implementation, the overall shape of the pole group body 22 is cylindrical.

[0079] In this utility model, see Figure 3 As shown, it should be noted that, for the utility model, the pole piece 30 constituting the battery pole group 2 has a discontinuous pole ear structure, and the shaped front pole ear 31 on the pole piece 30 is a discontinuous pole ear structure, which is made into the battery pole group 2 by winding. The pole group is shaped so that the pole ears of different layers are superimposed on each other, and finally a shaped butterfly-shaped pole ear 21 is formed; wherein, when the pole group is wound, the first two circles of the pole piece have no pole ears, and from the second circle onwards, each circle contains two symmetrical pole ears, which are shaped like a butterfly, and the central angle α of this butterfly-shaped pole ear is 30°~90°, and this pole ear can be connected to the collecting plate by laser welding.

[0080] It should be noted that, for the present invention, the two ends of the pole group are butterfly-shaped pole ears, and the remaining parts are filled with active materials. The butterfly-shaped pole ears match the current collecting plate and are connected by laser welding.

[0081] In specific implementation, the material of the butterfly-shaped electrode ear is copper (when used as a negative electrode ear) or aluminum (when used as a positive electrode ear).

[0082] In specific implementation, the position and size of the pole ear on the pole piece 30 (i.e. the pole ear 31 before shaping) are shown in FIG. Figure 3 There is no pole ear at the front end of the pole piece, and it starts to have a pole ear after the second circle. The position and length of the pole ear are calculated as follows:

[0083] Radius of winding needle:

[0084] When winding into a battery electrode group, the thickness of the positive and negative electrodes and the separator in the first circle is: d = d 正 +d 负 +2d 隔 ;

[0085] The radius of the nth pole group: r n =r0+nd;

[0086] The location of the first tab after the second lap: l 2,1 =2πr1+2πr2;

[0087] The position of the second pole ear after the second circle: l 2,2 =2πr1+2πr2+πr3;

[0088] The length of the first lug after the second circle: Δl 2,1=αr2;

[0089] The length of the second lug after the second circle: Δl 2,2 =αr2;

[0090] …

[0091] The position of the first pole ear after the nth circle: l n,1 =2πr1+2πr2+…+2πr n ;

[0092] The position of the second pole ear after the nth circle: l 2,2 =2πr1+2πr2+…+2πr n +πr n+1 ;

[0093] The length of the first lug after the nth circle: Δl n,1 =αr n ;

[0094] The length of the second pole ear after the nth circle: αl n,2 =αr n ;

[0095] In the above, n≥2, n is an integer.

[0096] Where d0 is the winding needle diameter, d 正 is the thickness of the positive electrode sheet, d 负 is the thickness of the negative electrode sheet, d 隔 is the thickness of the diaphragm, n represents the number of turns of the positive (or negative) electrode sheet, α is the angle of the butterfly ear (i.e. the corresponding center angle), r n is the radius of the nth winding of the pole group (n is a natural number greater than 1), l n,1 is the position of the nth tab, l n,2 is the position of the pole ear opposite to the nth pole ear; Δln ,1 and Δln ,2 It is the length of the two pole ears after the nth circle.

[0097] It should be noted that, for the present invention, the specific shape and size of the pole ear and the collector plate are designed according to the specific application model, and can be expanded and designed according to this shape, and finally the two can match each other. Because the weldable area is large, continuous laser welding can be used, which is stronger than traditional spot welding and meets the high power performance and high reliability of the battery.

[0098] Based on the above Figures 1 to 4 The new connection structure between the battery electrode group and the current collecting plate provided by the utility model as shown in FIG. Figure 5As shown, the utility model also provides a lithium-ion battery, which includes the novel connection structure between the battery electrode group and the current collecting plate as described above.

[0099] The battery electrode group 2 is arranged in the inner cavity of the battery housing 3 .

[0100] In specific implementation, a vertically penetrating boss mounting through hole is provided at the center of the top shell 31 of the battery shell 3;

[0101] The first boss 11 on the current collecting plate 1 is arranged in the boss mounting through hole;

[0102] The second boss 12 protrudes upward from the top surface of the top shell 31 of the battery shell 3;

[0103] The top shell 31 is laser welded to the first boss 11 .

[0104] In a specific implementation, the top surface height of the first boss 11 is the same as the top surface height of the top shell 31 , and they are located on the same horizontal plane.

[0105] It should be noted that see Figure 5 As shown, the boss structure on the current collecting plate 1 with the injection hole (specifically, the first boss 11 and the second boss 12 in the boss structure) passes through the through hole (i.e., the boss mounting through hole) reserved on the top shell 31 of the battery shell 3;

[0106] The top surface of the first boss 11 is flush with the top surface of the top shell 31, and a gap 320 is formed between the circumferential outer side wall of the first boss 11 and the inner side wall of the through hole reserved on the top shell 31, and then laser welding is performed at the gap 320. The height of the first boss 11 is flush with the top shell 31 with the through hole, and the diameter of the first boss 11 matches the aperture size of the through hole of the top shell 31 (slightly smaller to form the gap 320) and is concentric to form a suitable assembly, and the specific size is designed according to the battery model.

[0107] It should be noted that the lower end of the welding area of ​​the current collecting plate with the injection hole is connected to the butterfly-shaped pole ear of the pole group. The electrolyte enters from the injection hole 130 and directly contacts the inside of the battery cell pole group, thereby infiltrating the entire battery cell. The infiltration effect is fast and uniform, further improving the later formation effect and charge and discharge performance of the battery.

[0108] It should be noted that the novel connection structure of the battery electrode group and the current collecting plate is welded to the battery shell to form a battery cell, and multiple cells are further formed into a module, which can be Figure 5 The connection surface 330 (i.e., the circumferential outer side surface of the second boss 12) is welded. The butt welding method can effectively reduce the risk of leakage, improve the yield rate, and reduce the waste and loss of good quality batteries when assembling modules compared to the penetration welding method.

[0109] It should be noted that when the current collecting plate with injection holes is connected to the battery housing and the single cell to form a module structure, laser welding is used to ensure the reliability and sealing of the battery single cell, widen the electron channel, enhance the battery's large current passing capacity, and further improve the battery's power performance.

[0110] Compared with the prior art, the novel connection structure between the battery electrode group and the current collecting plate and the lithium ion battery provided by the utility model have the following beneficial effects:

[0111] 1. For the utility model, the pole ear of the battery pole group is a butterfly-type pole ear, and its design ensures the effective welding area with the collecting plate, the battery internal resistance is lower, the energy transmission efficiency is higher, and the battery power performance is better.

[0112] 2. The butterfly-shaped tabs of the utility model are easy to shape, and the probability of puncturing the diaphragm is lower than that of the traditional flattening. It is only necessary to flatten the tabs in the same direction, which is simple to operate and highly safe.

[0113] 3. The utility model optimizes the free space inside the battery. Except for the butterfly-shaped pole ear, the space on the same layer is blank, which reserves more space for the electrolyte and the gas that may be generated inside the battery in the future, which helps to extend the battery life and enhance the battery safety performance. On the other hand, the blank space can be increased as active material, increasing the proportion of active material in the battery and improving the capacity of the battery.

[0114] 3. For the utility model, the current collecting plate with the injection hole can be closely matched with the electrode group. The injection hole with a through structure simplifies the injection process, and the electrolyte directly infiltrates into the inner core of the electrode through the injection hole. The electrolyte movement path is short, the infiltration speed is fast, and the contact area is large, which improves the wettability of the battery and ultimately ensures the electrical performance of the battery.

[0115] 4. For the utility model, the current collecting plate with the injection hole has a stepped structure of the injection hole, which can improve the yield rate of the battery sealing, and is different from the direct welding on the injection hole port, which will have welding slag and other phenomena, affecting the battery monomer assembly.

[0116] 5. For the utility model, the shape of the welding area of ​​the current collecting plate with the injection hole can be determined according to actual needs, and it can meet the requirements of cylindrical batteries of different sizes, which can ensure a larger welding area, high structural reliability of the battery, low internal resistance of the battery, and greatly improve the power performance of the battery. Especially for small-sized cylindrical batteries with a diameter of 10-40mm, the internal space of the battery is small and the welding area needs to be improved urgently. The use of the current collecting plate can greatly improve its welding effect, ensure a larger welding area, improve the power performance of the battery, and do not affect the entry and infiltration of the electrolyte.

[0117] 6. For the utility model, the current collecting plate with the injection hole and the battery housing and multiple battery cells form a modular structure, which are all connected by laser welding, ensuring the reliability and sealing of the battery cells, making the electronic channel wider, enhancing the battery's large current passing capacity, and further improving the battery's power performance.

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A novel connection structure between a battery electrode group and a current collecting plate, characterized in that: It comprises a battery electrode group (2) and a current collecting plate (1); A battery electrode group (2), comprising a butterfly-shaped electrode ear (21) and an electrode group body (22); The current collecting plate (1) is located directly above the electrode group body (22); The top end of the pole group body (22) for connecting to the current collecting plate (1) is provided with two butterfly-shaped pole ears (21); The top of the butterfly-shaped pole ear (21) is laser welded to the bottom of the current collecting plate (1); Wherein, a boss structure is provided at the center of the current collecting plate (1); A vertically penetrating liquid injection hole (130) is provided in the boss structure; A welding area (14) is provided at the left and right ends of the current collecting plate (1); The two welding area portions (14) are centrally symmetrically distributed; Two welding area portions (14) are respectively connected to two sides of the bottom end of the boss structure; The bottom surface of the welding area portion (14) is laser welded to the top of the butterfly-shaped pole ear (21).

2. The novel connection structure between the battery electrode group and the current collecting plate according to claim 1, characterized in that: The top and bottom surfaces of the butterfly-shaped pole ear (21) are both fan-shaped.

3. The novel connection structure between the battery electrode group and the current collecting plate according to claim 2, characterized in that: The shape of the top surface of the butterfly-shaped pole ear (21) is smaller than the shape of the bottom surface; and / or, The central angle α of the butterfly-shaped pole ear is 30°~90°.

4. The novel connection structure between a battery electrode group and a current collecting plate according to claim 1, characterized in that: The pole group body (22) is provided with a central through hole (230) at a position between the two butterfly-shaped pole ears (21); A central through hole (230) vertically penetrates the pole group body (22); The central through hole (230) is located directly below the liquid injection hole (130).

5. The novel connection structure between a battery electrode group and a current collecting plate according to any one of claims 1 to 4, characterized in that: The boss structure of the current collecting plate (1) comprises a hollow second boss (12), a first boss (11), a concave boss (16) and a second boss bottom plate (13); A first boss (11) is provided on the top of the second boss chassis (13); A hollow second boss (12) is provided on the top of the first boss (11); The inner cavity of the second protrusion (12) is surrounded by a concave platform (16); A liquid injection hole (130) is provided in the concave platform (16); Both sides of the second boss chassis (13) are respectively connected to a welding area portion (14).

6. The novel connection structure between the battery electrode group and the current collecting plate according to claim 5, characterized in that: A liquid injection hole (130) vertically penetrates the second boss (12), the first boss (11), the concave boss (16) and the second boss bottom plate (13); The cross-sectional shapes of the second boss (12), the first boss (11) and the concave boss (16) are all circular; The two side edges of the welding area (14) are provided with upwardly protruding long strip-shaped reinforcing ribs (15).

7. The novel connection structure between a battery electrode group and a current collecting plate as claimed in claim 5, characterized in that: The center points of the injection hole (130), the second boss (12), the first boss (11) and the concave boss (16) are located on the same central axis; The outer diameters of the concave platform (16), the second convex platform (12) and the first convex platform (11) increase in sequence; The vertical heights of the first convex platform (11), the concave platform (16) and the second convex platform (12) increase in sequence.

8. The novel connection structure between a battery electrode group and a current collecting plate as claimed in claim 5, characterized in that: At least one positioning hole (17) is provided on the welding area portion (14); The edge shapes of the two welding area parts (14) on the opposite sides are arc-shaped.

9. A lithium ion battery, characterized in that: A novel connection structure between a battery electrode group and a current collecting plate as claimed in any one of claims 1 to 8; The battery electrode group (2) is arranged in the inner cavity of the battery casing (3).

10. The lithium ion battery according to claim 9, characterized in that A boss mounting through hole is provided at the center of the top shell (31) of the battery shell (3) and extends vertically through the top shell (31). The first boss (11) on the current collecting plate (1) is arranged in the boss mounting through hole; A second boss (12) protrudes upward from a top surface of a top shell (31) of the battery shell (3); A top shell (31) is laser welded to the first boss (11); The top surface height of the first boss (11) is the same as the top surface height of the top shell (31), and they are located on the same horizontal plane.

Images