Current collecting needle, cover plate assembly and battery

Abstract

The application provides a current collecting needle, a cover plate assembly and a battery, and relates to the technical field of batteries. The current collecting needle comprises a body and a protruding block; the protruding block is arranged on the outer circumferential surface of the body. By arranging the protruding block on the body, on the one hand, the structural strength of the body can be increased, so that the current collecting needle can be prevented from being damaged due to insertion into the positive electrode, thereby facilitating the guarantee of the structural integrity of the current collecting needle; on the other hand, the surface area of the current collecting needle can be increased, so that the contact area between the current collecting needle and the positive electrode can be increased. In this way, the current collecting capacity of the current collecting needle can be increased, thereby improving the reliability of the lithium sub-battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a current collector, a cover plate assembly, and a battery. Background Technology

[0002] In related technologies, a lithium-thionyl phosphate battery is a battery that uses lithium metal or lithium alloy as the negative electrode material and a non-aqueous electrolyte solution. The structure of a lithium-thionyl phosphate battery includes a casing, a positive electrode, a negative electrode, a side film, a bottom film, a top cover film, and a cover plate assembly for sealing the casing. The cover plate assembly includes a cover plate, current collectors, and an insulating component. The current collectors pass through the cover plate, and the insulating component is installed between the current collectors and the cover plate to insulate and isolate them. The insulating component can be glass, and an insulating structure can be formed between the cover plate and the current collectors through a glass sealing method.

[0003] Currently, lithium-ion batteries have poor reliability. Utility Model Content

[0004] Embodiments of this application provide a current collector, a cover plate assembly, and a battery, which can improve the reliability of lithium-ion batteries.

[0005] In a first aspect, embodiments of this application provide a flow collecting needle, which includes a body and a protrusion; the protrusion is disposed on the outer peripheral surface of the body.

[0006] Optionally, the bump is annular, and the bump is arranged to surround the body circumferentially.

[0007] Optionally, the body has an insertion portion configured to insert a positive electrode, and the outer diameter of the bump gradually increases in the direction away from the insertion portion.

[0008] Optionally, there are multiple bumps, and the multiple bumps are sequentially arranged on the outer peripheral surface of the body along the axial direction of the collecting needle.

[0009] Optionally, two adjacent protrusions along the axial direction of the body are connected to each other.

[0010] Optionally, the outer diameter of the end of the protrusion near the insertion part is D1, and the outer diameter of the end of the protrusion away from the insertion part is D2. Along the axial direction of the body, the protrusion has a height dimension H1, which satisfies: H1≥2(D2-D1).

[0011] Optionally, the generatrix of the outer peripheral surface of the protrusion has an angle α with the axis of the body, satisfying: 5°≤α≤45°.

[0012] Optionally, the body has an insertion portion configured to insert a positive electrode, the outer diameter of the end of the protrusion near the insertion portion is D1, and the outer diameter of the body is D3, satisfying: D1 < D3.

[0013] Optionally, the outer peripheral surface of the bump is a conical surface.

[0014] Optionally, the bump has a spiral structure, with the bump extending spirally around the axis of the body.

[0015] Optionally, there are multiple bumps, and the multiple bumps are spaced apart along the circumference of the body.

[0016] Optionally, the two ends of the body are an insertion part and a connecting part, respectively. The insertion part is configured to be inserted into the positive electrode. The outer peripheral surface of the insertion part is a conical surface, and the outer diameter of the insertion part gradually decreases in the direction away from the connecting part.

[0017] Optionally, the diameter of the end of the insertion part away from the connecting part is D4, where D4 is the minimum diameter of the body.

[0018] Secondly, embodiments of this application provide a cover plate assembly, which includes a cover plate, an insulating ring, and the aforementioned current collecting pin; the end cap is provided with a mounting hole; the body is inserted into the mounting hole, the insulating ring is located inside the mounting hole, and the inner and outer peripheral surfaces of the insulating ring are respectively connected to the body and the hole wall of the mounting hole.

[0019] Thirdly, embodiments of this application provide a battery comprising a casing, a negative electrode, a positive electrode, a side membrane, a support, and the aforementioned cover assembly; the negative electrode is disposed on the inner wall of the casing; the positive electrode is disposed on the inner side of the negative electrode; the side membrane is disposed between the negative electrode and the positive electrode; the support is disposed at one end of the positive electrode, and the support is provided with a mating hole and a liquid passage hole; the end cap is closed with the casing, and the body passes through the mating hole.

[0020] Optionally, the body is provided with a shoulder, which is located between the bracket and the end cap. The diameter of the body at the end of the shoulder away from the bracket is D5, and the diameter of the body at the end of the shoulder close to the bracket is D3. The diameter of the mating hole is D6, satisfying: D6≤D3<D5.

[0021] Optionally, a flared opening is provided at the end of the mating hole facing the shaft shoulder, and the diameter of the end of the flared opening facing the shaft shoulder is D7, satisfying: D7 > D5.

[0022] Optionally, a support ring is provided at the end of the bracket away from the positive electrode, and the support ring extends along the circumference of the body.

[0023] Optionally, there are multiple support rings, which are arranged at radial intervals along the body; and / or, the distance between the end face of the support ring facing away from the positive electrode and the end face of the bracket facing away from the positive electrode is H2, satisfying: 0.1mm≤H2≤0.5mm.

[0024] Optionally, a recessed platform is provided on the end face of the support away from the positive electrode, and a mating hole penetrates the bottom wall of the recessed platform; and / or, a boss is provided on the end face of the support near the positive electrode, and the boss is arranged around the axis of the body.

[0025] The beneficial effects of the embodiments of this application are as follows:

[0026] In the embodiments of this application, by providing protrusions on the body, on the one hand, the structural strength of the body can be increased, thereby preventing the current collector pin from being damaged when inserted into the positive electrode, thus ensuring the structural integrity of the current collector pin; on the other hand, the surface area of ​​the current collector pin can be increased, thereby increasing the contact area between the current collector pin and the positive electrode. Thus, the current collecting capacity of the current collector pin can be increased, thereby improving the reliability of the lithium-ion battery. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the manifold structure provided in an embodiment of this application;

[0029] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0030] Figure 3 This is a schematic diagram of another manifold provided in an embodiment of this application;

[0031] Figure 4 yes Figure 1 Enlarged view of point B in the middle;

[0032] Figure 5 This is a schematic diagram of the structure of the cover plate assembly provided in an embodiment of this application;

[0033] Figure 6 This is a schematic diagram of the battery structure provided in an embodiment of this application;

[0034] Figure 7 This is a schematic diagram of the structure of the bracket provided in an embodiment of this application.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1-Collector pin; 11-Body; 111-Shoulder; 12-Protrusion; 13-Insertion part; 14-Busline; 15-Connecting part;

[0037] 2-Cover plate assembly; 21-Cover plate; 211-Mounting hole; 22-Insulating ring;

[0038] 3-Battery; 31-Casing; 32-Negative electrode; 33-Positive electrode; 34-Side film; 35-Support; 351-Matching hole; 352-Liquid passage hole; 353-Flame mouth; 354-Support ring; 355-Sinking platform; 356-Protrusion; 36-Bottom film; 37-Top cover film. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0040] Before introducing the current collector 1, cover plate assembly 2 and battery 3 provided in the embodiments of this application, the relevant technologies of this application will be explained first.

[0041] In related technologies, during the assembly of the lithium-ion battery 3, the negative electrode 32 is first installed on the inner wall of the housing 31. Then, the side film 34 is installed inside the negative electrode 32. Next, the positive electrode 33 is placed inside the side film 34. Then, a top film and a support 35 are placed on top of the positive electrode 33. Next, the cover plate assembly 2 is fitted to the housing 31, such that the end of the current collector 1 of the cover plate assembly 2 passes through the support 35 and the top film and is inserted into the positive electrode 33. Then, the end cap of the cover plate assembly 2 is welded to the housing 31. Finally, electrolyte is injected into the housing 31 through the injection hole on the end cap, and the injection hole is sealed.

[0042] When the current collector 1 is inserted into the positive electrode 33, due to its small size and the inherent toughness of the positive electrode 33, it is prone to cracking upon insertion into the carbon pack, resulting in poor contact between the current collector 1 and the positive electrode 33. The toughness of the positive electrode 33 when it is in carbon pack form is greater than when it is in granular form. Therefore, when the positive electrode 33 is in carbon pack form, the cracking of the current collector 1 after insertion is more pronounced. Furthermore, when the positive electrode 33 is in granular form, the contact between the current collector 1 and the positive electrode 33 is point contact, resulting in fewer contact areas and poorer contact between them. Consequently, the current collecting capacity of the current collector 1 is poor, leading to lower reliability of the lithium-ion battery 3.

[0043] Based on this, embodiments of this application provide a current collector 1, a cover plate assembly 2, and a battery 3. This not only improves the strength of the current collector 1 to reduce damage caused by the positive electrode 33 during insertion and prevents breakage of the current collector 1, but also increases the contact area between the current collector 1 and the positive electrode 33. Thus, the current collection capacity of the current collector 1 is improved, thereby enhancing the reliability of the lithium-ion battery 3.

[0044] The following combination Figures 1 to 7 The present application provides a detailed description of a current collector 1, a cover plate assembly 2, and a battery 3.

[0045] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a current collector 1 provided in an embodiment of this application. In a first aspect, an embodiment of this application provides a current collector 1. The current collector 1 includes a body 11 and a protrusion 12. The protrusion 12 is disposed on the outer peripheral surface of the body 11.

[0046] The protrusion 12 can be a ring structure, sleeved on the body 11. In this case, there can be multiple protrusions 12, arranged sequentially along the axial direction of the body 11. The protrusion 12 can also include multiple sub-blocks, spaced apart circumferentially along the body 11. Furthermore, the sub-blocks between adjacent protrusions 12 can correspond one-to-one along the axial direction of the body 11, or they can be staggered along the circumferential direction of the body 11. The protrusion 12 can also be a spiral structure, extending spirally around the axis of the body 11. In this case, there can be one or more protrusions 12. When there are multiple protrusions, they are spaced apart circumferentially along the body 11.

[0047] For example, the bump 12 can be integrally formed with the body 11, or the bump 12 can be welded to the body 11.

[0048] For example, the manifold 1 is made of nickel-based alloy, nickel-cobalt-based alloy, or stainless steel.

[0049] Optionally, the current collecting pin 1 can be a hollow structure, thereby reducing the weight and material usage of the current collecting pin 1, and consequently reducing the weight and material cost of the battery 3.

[0050] Specifically, the surface of the current collector 1 can be treated with processes that enhance conductivity, such as nickel plating, gold plating, or carbon coating.

[0051] In this embodiment, by providing protrusions 12 on the body 11, on the one hand, the structural strength of the body 11 can be increased, thereby preventing the current collector 1 from being damaged when inserted into the positive electrode 33, thus ensuring the structural integrity of the current collector 1; on the other hand, the surface area of ​​the current collector 1 can be increased, thereby increasing the contact area between the current collector 1 and the positive electrode 33. Thus, the current collecting capacity of the current collector 1 can be increased, thereby improving the reliability of the lithium-ion battery 3.

[0052] Please see Figure 1 In some embodiments, the protrusion 12 is annular. The protrusion 12 is arranged around the circumference of the body 11. The protrusion 12 can be integrally formed with the body 11, or the protrusion 12 can be sleeved on the body 11. In this way, the surface area of ​​the current collector can be increased and the structural strength of the current collector can be improved. It can also improve the structural symmetry of the current collecting needle 1, thereby improving the stress state of the current collector and thus improving the structural reliability of the current collector.

[0053] Please see Figure 1 and Figure 2 , Figure 2 yes Figure 1 Enlarged view at point A. In some embodiments, the body 11 has an insertion portion 13 configured to insert the positive electrode 33. The outer diameter of the protrusion 12 gradually increases in the direction away from the insertion portion 13.

[0054] It is understandable that the outer diameter of the bump 12 can change linearly or as a curve.

[0055] It is understandable that the part of the protrusion 12 near the insertion part 13 is the small diameter end, and the part away from the insertion part 13 is the large diameter end.

[0056] In this embodiment, through the above-mentioned arrangement, on the one hand, the small-diameter end of the protrusion 12 can guide each protrusion 12 when it is inserted into the positive electrode 33, thereby improving the smoothness of the insertion of the current collector 1 into the positive electrode 33; on the other hand, the small-diameter end of the protrusion 12 is inserted into the positive electrode 33 first, so that the protrusion 12 has a smaller force-bearing area through the small-diameter end, thereby increasing the pressure of the protrusion 12 pressing the positive electrode 33, which is conducive to improving the ease of operation of inserting the protrusion 12 into the positive electrode 33.

[0057] Please see Figure 1 In some embodiments, there are multiple protrusions 12. Multiple protrusions 12 are sequentially arranged on the outer peripheral surface of the body 11 along the axial direction of the collecting pin 1. In this way, the structural strength of the collecting pin 1 can be enhanced, and the surface area of ​​the collecting pin 1 can be increased, thereby improving the flow rate of the collecting pin 1.

[0058] Please see Figure 1 and Figure 2In some embodiments, two adjacent protrusions 12 along the axial direction of the body 11 are connected to each other. This allows for the provision of more protrusions 12 along a certain length of the body 11, thereby not only improving the structural strength of the current collector 1 but also increasing its surface area. This increases the current collection capacity of the current collector 1, which is beneficial for improving the reliability of the lithium-thionyl chloride battery 3.

[0059] Please see Figure 2 In some embodiments, the outer diameter of the end of the protrusion 12 near the insertion portion 13 is D1, and the outer diameter of the end of the protrusion 12 away from the insertion portion 13 is D2. Along the axial direction of the body 11, the protrusion 12 has a height dimension H1, which satisfies: H1≥2(D2-D1).

[0060] Specifically, the height dimension of the body 11 is H0, and 2(D2-D1)≤H1≤10%H0.

[0061] In this embodiment, the above-mentioned limitations allow for sufficient spacing between the two ends of the protrusion 12 to facilitate the forming of the protrusion 12, thereby improving the structural strength of the protrusion 12 and the connection strength between the protrusion 12 and the body 11.

[0062] In addition, when the positive electrode 33 is granular, the value of H1 can be set to be larger so that the bump 12 has a larger inclined surface that can be released from the positive electrode 33, thereby increasing the contact area between the current collector 1 and the positive electrode 33, which is beneficial to improving the current collection capacity of the current collector 1.

[0063] Please see Figure 2 In some embodiments, the generatrix 14 of the outer peripheral surface of the protrusion 12 has an included angle α with the axis of the body 11, satisfying: 5°≤α≤45°.

[0064] It is understood that the included angle α includes, but is not limited to, 5°, 7.2°, 10°, 10.5°, 12.8°, 15.1°, 17.6°, 20.3°, 22.7°, 25.0°, 27.4°, 29.9°, 32.2°, 34.6°, 36.8°, 39.1°, 41.5°, 42.9°, 44.2°, 44.6°, 44.9°, and 45°.

[0065] In this embodiment, the above-mentioned limitations allow the outer peripheral surface of the bump 12 to have an inclination, which helps to increase the contact area between the bump 12 and the positive electrode 33. On the other hand, the inclination of the outer peripheral surface of the bump 12 can be avoided to be too large, so that more positive electrode 33 material, especially particulate positive electrode 33 material, can be embedded between two adjacent bumps 12.

[0066] The height H1 of each protrusion 12 and the angle α between the generatrix 14 of the outer peripheral surface of the protrusion 12 and the axis of the body 11 can be adjusted according to the particle size of the positive electrode 33 to achieve a better conductivity. For example, if the particle size of the positive electrode 33 is small, a larger angle α and a smaller height H1 can be selected. Thus, based on the fact that the positive electrode 33 and the current collector have a schematic contact area, more protrusions 12 can be set on the body 11 to improve the structural strength of the current collector needle 1.

[0067] Please see Figure 1 and Figure 2 In some embodiments, the body 11 has an insertion portion 13 configured to insert the positive electrode 33. The outer diameter of the end of the protrusion 12 near the insertion portion 13 is D1, and the outer diameter of the body 11 is D3, satisfying: D1 < D3.

[0068] In this embodiment, the above-mentioned limitations allow the outer periphery of the protrusion 12 to extend into the body 11, thereby increasing the surface area of ​​the current collecting needle 1 while maintaining a fixed outer diameter. This increases the contact area between the current collecting needle 1 and the positive electrode 33, which is beneficial for improving the current collecting capacity of the current collecting needle 1.

[0069] Please see Figure 2 In some embodiments, the outer peripheral surface of the bump 12 is a conical surface. This improves the guidance of the bump 12 for the current collector 1 to be inserted into the positive electrode 33, and also improves the uniformity of the current collector 1 on its outer peripheral surface, so that the current collector 1 can withstand a greater load.

[0070] Please see Figure 3 , Figure 3 This is a schematic diagram of another current collector 1 provided in an embodiment of this application. In some embodiments, the protrusion 12 has a spiral structure. The protrusion 12 extends spirally around the axis of the body 11. In this way, the current collector 1 can be inserted into the positive electrode 33 by twisting, thereby improving the ease of insertion of the current collector 1 into the positive electrode 33 and reducing the resistance of the positive electrode 33 to the current collector 1, so as to improve the acceptance state of the current collector 1.

[0071] Optionally, there are multiple protrusions 12, which are spaced apart circumferentially along the body 11. This improves the structural symmetry of the collecting pin 1, thereby improving the stress state of the collecting pin 1. The spiral arrangement of the protrusions 12 can be one turn or extend to the insertion part 13. When there are N protrusions 12, the central angle corresponding to each protrusion 12 is no greater than 360° / N. For example, if there are 4 protrusions 12, the central angle corresponding to each protrusion 12 is 60°, and the central angle corresponding to the interval between two circumferentially adjacent protrusions 12 is 30°.

[0072] It is understood that current collectors with annular or spiral protrusions 12 can be applied to both granular carbon cathodes 33 and integrated columnar carbon cathodes 33 (i.e., carbon packs). To better improve the current flow between these two structures and the cathode 33, current collectors with annular protrusions 12 can be applied to granular carbon cathodes 33, while current collectors with spiral protrusions 12 can be applied to integrated columnar carbon cathodes 33.

[0073] Please see Figure 1 In some embodiments, the two ends of the body 11 are an insertion portion 13 and a connecting portion 15, respectively. The insertion portion 13 is configured to be inserted into the positive electrode 33. The outer peripheral surface of the insertion portion 13 is a conical surface. The outer diameter of the insertion portion 13 gradually decreases in the direction away from the connecting portion 15.

[0074] In this embodiment, through the above-mentioned arrangement, on the one hand, the small-diameter end of the insertion part 13 can guide the current collector 1 when it is inserted into the positive electrode 33, thereby improving the smoothness of the current collector 1 being inserted into the positive electrode 33; on the other hand, the small-diameter end of the insertion part 13 is inserted into the positive electrode 33 first, so that the current collector 1 has a smaller force-bearing area through the small-diameter end, thereby increasing the pressure of the current collector 1 pressing the positive electrode 33, which is conducive to improving the ease of operation of inserting the current collector 1 into the positive electrode 33.

[0075] Please see Figure 4 , Figure 4 yes Figure 1 Enlarged schematic diagram at point B. In some embodiments, the diameter of the end of the insertion part 13 facing away from the connecting part 15 is D4, where D4 is the minimum diameter of the body 11. This allows the current collecting needle 1 to have a smaller diameter end for inserting into the positive electrode 33, thereby improving the smoothness of insertion of the current collecting needle 1 into the positive electrode 33, while also allowing other parts of the current collecting needle 1 to have larger dimensions, thereby helping to ensure the structural strength of the current collecting needle 1.

[0076] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of the cover plate assembly 2 provided in an embodiment of this application. In a second aspect, an embodiment of this application provides a cover plate assembly 2. The cover plate assembly 2 includes a cover plate 21, an insulating ring 22, and the aforementioned current collecting needle 1. The end cap is provided with a mounting hole 211. The body 11 passes through the mounting hole 211. The insulating ring 22 is located within the mounting hole 211. The inner and outer circumferential surfaces of the insulating ring 22 are respectively connected to the body 11 and the hole wall of the mounting hole 211.

[0077] It is understood that the cover plate assembly 2 includes the aforementioned collecting needle 1, and therefore the cover plate assembly 2 has all the beneficial effects of the aforementioned collecting needle 1, which will not be repeated here in this embodiment.

[0078] Please see Figure 6 , Figure 6 This is a schematic diagram of the structure of the battery 3 provided in an embodiment of this application. In a third aspect, an embodiment of this application provides a battery 3. The battery 3 includes a casing 31, a negative electrode 32, a positive electrode 33, a side film 34, a support 35, and the aforementioned cover assembly 2. The negative electrode 32 is disposed on the inner wall of the casing 31. The positive electrode 33 is disposed inside the negative electrode 32. The side film 34 is disposed between the negative electrode 32 and the positive electrode 33. The support 35 is disposed at one end of the positive electrode 33. The support 35 is provided with a mating hole 351 and a liquid passage hole 352. An end cap is closed to the casing 31. The body 11 passes through the mating hole 351.

[0079] It can be understood that battery 3 is a lithium-thionyl chloride battery 3, specifically a lithium thionyl chloride battery 3. The positive electrode active material 33 of the lithium thionyl chloride battery 3 is a mixture of porous carbon and thionyl chloride. The negative electrode material 32 of the lithium thionyl chloride battery 3 is metallic lithium.

[0080] It is understood that battery 3 also includes a bottom film 36. The bottom film 36 is disposed between the positive electrode 33 and the bottom wall of the casing, and is used to insulate and isolate the positive electrode 33 and the bottom wall of the casing.

[0081] It is understood that the battery 3 also includes an upper cover film 37. The upper cover film 37 is disposed on top of the positive electrode 33 and is used to insulate and isolate the positive electrode 33 from the cover plate 21.

[0082] The edge membrane 34 insulates and isolates the positive electrode 33 and the negative electrode 32. The liquid passage 352 facilitates the flow of electrolyte during liquid injection, thereby improving the liquid injection efficiency and the wetting efficiency of the positive and negative electrodes 32.

[0083] For example, the material of the support 35 is an insulating material, specifically a fluoroplastic such as PFA (fusible polytetrafluoroethylene) or PTFE (polytetrafluoroethylene).

[0084] It is understood that the battery 3 includes the aforementioned cover assembly 2, and therefore the battery 3 has all the beneficial effects of the aforementioned cover assembly 2, which will not be repeated here in this embodiment.

[0085] Please see Figure 6 and Figure 7 , Figure 7 This is a schematic diagram of the structure of the bracket 35 provided in an embodiment of this application. In some embodiments, a shoulder 111 is provided on the body 11. The shoulder 111 is located between the bracket 35 and the end cap. The diameter of the end of the body 11 located on the shoulder 111 away from the bracket 35 is D5, the diameter of the end of the body 11 located on the shoulder 111 near the bracket 35 is D3, and the diameter of the mating hole 351 is D6, satisfying: D6≤D3<D5.

[0086] It is understandable that D4 < D6, so as to facilitate the guidance of the flow collecting needle 1 through the mating hole 351 via the insertion part 13, thereby improving the ease of assembly between the flow collecting needle 1 and the bracket 35.

[0087] Where D6≤D3, the fit between the body 11 and the support 35 can be either an interference fit or a transition fit. Therefore, when the battery 3 is assembled and liquid is injected, after the positive electrode 33 absorbs liquid and expands, the upward pushing force exerted by the positive electrode 33 on the support 35 needs to be greater than the frictional force between the support 35 and the current collector 1. This causes the support 35 to move upward relative to the current collector 1. In this way, the contact area between the positive electrode 33 and the support 35 can be increased, effectively preventing gaps between the positive electrode 33 and the support 35 that could lead to poor discharge of the battery 3.

[0088] Since D3 < D5 and D6 < D5, when the positive electrode 33 expands significantly, the shoulder 111 can be used to stop and cooperate with the bracket 35 to limit the upward movement of the bracket 35, thereby controlling the expansion of the positive electrode 33 and preventing the positive electrode 33 from bursting the upper cover film 37 due to excessive expansion force.

[0089] Please see Figure 7 In some embodiments, a flared opening 353 is provided at the end of the mating hole 351 facing the shoulder 111, and the diameter of the end of the flared opening 353 facing the shoulder 111 is D7, satisfying: D7 > D5. In this way, the flared opening 353 can guide the mating between the manifold 1 and the bracket 35, thereby improving assembly efficiency.

[0090] Specifically, D4 < D1 < D3 < D7 < D2 < D5.

[0091] It is understandable that the design of the aperture of the mating hole 351 of the bracket 35 matches the dimensions of a portion of the current collector 1. By varying the mating gap between the current collector 1 and the mating hole 351, the clamping force of the bracket 35 on the positive electrode 33 under different temperature conditions can be adjusted. Furthermore, it can also achieve the purpose of clamping the positive electrode 33 of the battery 3 at different stages. Specific details are as follows:

[0092] During the assembly stage: Since D4 is less than D6 and both the insertion part 13 and the flare are designed with an angle, the fitting clearance when the insertion part 13 is inserted into the mating hole 351 can be increased; during the insertion process, D6 is less than D2, so that the current collector 1 and the bracket 35 are interference fit, thereby generating resistance to press the positive electrode 33 through the bracket 35 until the D3 dimension section of the current collector 1 is mated with the mating hole 351.

[0093] During the liquid injection stage: the D3 segment of the collector needle 1 mates with the mating hole 351, and D6 is less than or equal to D3, making the resistance between the D3 segment of the collector needle 1 and the support 35 less than the resistance between the D2 segment of the collector needle 1 and the support 35. Therefore, after the positive electrode 33 absorbs liquid, it expands, causing the support 35 to move along the D3 segment of the collector needle 1 under the action of the expansion force of the positive electrode 33.

[0094] During discharge: At room temperature and low temperature, the positive electrode 33 expands less, and D6 is less than D3. The resistance encountered by the support 35 when moving relative to the current collector 1 is small, allowing the support 35 to move along the D3 dimension segment of the current collector 1. When the battery 3 is discharging at high temperature and at the end of the discharge period, the positive electrode 33 expands significantly. However, since D7 > D5 and D6 < D5, this significantly hinders the upward movement of the support 35, thus controlling the expansion amplitude of the positive electrode 33. It can be understood that during this process, the relationship between the dimension D5 of the current collector 1 and the dimension D6 of the support 35 can be selected according to the battery 3's tolerance, adjusting the interference between the dimension D6 of the support 35 and the dimension D5 of the current collector 1, thereby adjusting the resistance when the support 35 and the current collector 1 are matched along the D5 dimension segment.

[0095] Please see Figure 7 In some embodiments, a support ring 354 is provided at the end of the bracket 35 opposite to the positive electrode 33. The support ring 354 extends along the circumference of the body 11. This increases the structural strength of the bracket 35 and improves the structural reliability of the battery 3.

[0096] Please see Figure 7 In some embodiments, there are multiple support rings 354, which are arranged radially spaced along the body 11. This further increases the structural strength of the bracket 35 and improves the structural reliability of the battery 3.

[0097] Please see Figure 7 The distance between the end face of the support ring 354 facing away from the positive electrode 33 and the end face of the bracket 35 facing away from the positive electrode 33 is H2, which satisfies: 0.1mm≤H2≤0.5mm.

[0098] It is understood that H2 includes, but is not limited to, 0.1mm, 0.102mm, 0.115mm, 0.121mm, 0.127mm, 0.134mm, 0.143mm, 0.156mm, 0.162mm, 0.171mm, 0.178mm, 0.183mm, 0.195mm, 0.202mm, 0.211mm, 0.224mm, 0.235mm, and 0.241mm. mm, 0.253mm, 0.262mm, 0.273mm, 0.284mm, 0.291mm, 0.302mm, 0.315mm, 0.327mm, 0.334mm, 0 .348mm, 0.362mm, 0.375mm, 0.412mm, 0.427mm, 0.434mm, 0.448mm, 0.462mm, 0.475mm, 0.5mm.

[0099] In this embodiment, the above-mentioned limitations can, on the one hand, ensure the minimum size of the support ring 354, so as to significantly improve the structural strength of the bracket 35; on the other hand, the height of the bracket 35 can be controlled to control the height of the battery 3 inside it, thereby facilitating the control of the height of the battery 3.

[0100] Please see Figure 7 In some embodiments, a recessed platform 355 is provided on the end face of the support 35 facing away from the positive electrode 33, and a mating hole 351 penetrates the bottom of the recessed platform 355. In this way, the strength of the part of the support 35 that mates with the current collector 1 can be reduced, so that when the current collector 1 passes through the mating hole 351, the part of the support 35 near the mating hole 351 can be elastically deformed, thereby reducing the obstruction of the current collector 1 passing through the support 35.

[0101] Please see Figure 7 A boss 356 is provided on the end face of the bracket 35 near the positive electrode 33. The boss 356 is arranged around the axis of the body 11. In this way, by providing the boss 356, the mating area between the current collecting needle 1 and the bracket 35 is increased. Also, because the outer diameter of the boss 356 is smaller than the outer diameter of the bracket 35, the strength of the boss 356 is lower and the elasticity is better. Therefore, when the current collecting needle 1 passes through the mating hole 351, the part of the bracket 35 near the mating hole 351 can be elastically deformed, thereby reducing the obstruction of the current collecting needle 1 passing through the bracket 35.

[0102] In addition, the protrusion 356 can also create a gap between the end face of the support 35 facing the positive electrode 33 and the positive electrode 33, thereby providing a channel for the flow of electrode liquid, which can improve the electrode liquid injection efficiency and the wetting efficiency of the positive and negative electrodes 32.

[0103] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A flow collecting needle, characterized in that, include: The body has an insertion portion configured to insert a positive electrode, and the outer diameter of the protrusion gradually increases in a direction away from the insertion portion; A protrusion is disposed on the outer peripheral surface of the body; the protrusion is annular and is disposed around the circumference of the body; there are multiple protrusions, which are sequentially disposed on the outer peripheral surface of the body along the axial direction of the collecting needle; two adjacent protrusions along the axial direction of the body are connected to each other. The outer diameter of the end of the protrusion near the insertion part is D1, and the outer diameter of the end of the protrusion away from the insertion part is D2. Along the axial direction of the body, the protrusion has a height dimension H1, satisfying: H1≥2(D2-D1); the generatrix of the outer peripheral surface of the protrusion has an angle α with the axis of the body, satisfying: 5°≤α≤45°.

2. The collecting needle according to claim 1, characterized in that, The outer diameter of the end of the protrusion near the insertion part is D1, and the outer diameter of the body is D3, satisfying: D1 < D3.

3. The collecting needle according to claim 1, characterized in that, The outer peripheral surface of the protrusion is a conical surface.

4. The collector needle according to any one of claims 1-3, characterized in that, The two ends of the main body are an insertion part and a connecting part, respectively. The insertion part is configured to be inserted into the positive electrode. The outer peripheral surface of the insertion part is a conical surface, and the outer diameter of the insertion part gradually decreases in the direction away from the connecting part.

5. The collecting needle according to claim 4, characterized in that, The diameter of the end of the insertion part away from the connecting part is D4, and D4 is the minimum diameter of the body.

6. A cover plate assembly, characterized in that, include: End cap, with mounting holes; Insulating ring; According to any one of claims 1-5, the main body is inserted into the mounting hole, the insulating ring is located inside the mounting hole, and the inner and outer circumferential surfaces of the insulating ring are respectively connected to the main body and the hole wall of the mounting hole.

7. A battery, characterized in that, include: case; The negative electrode is disposed on the inner wall of the housing; The positive electrode is located inside the negative electrode; A side membrane is disposed between the negative electrode and the positive electrode; A support, disposed at one end of the positive electrode, is provided with a mating hole and a liquid passage hole; and The cover plate assembly as claimed in claim 6, wherein the end cap is closed to the housing, and the body passes through the mating hole.

8. The battery according to claim 7, characterized in that, The body is provided with a shoulder, which is located between the bracket and the end cap. The diameter of the body at the end of the shoulder away from the bracket is D5, and the diameter of the body at the end of the shoulder close to the bracket is D3. The diameter of the mating hole is D6, satisfying: D6≤D3<D5.

9. The battery according to claim 8, characterized in that, A flared opening is provided at the end of the mating hole facing the shoulder, and the diameter of the flared opening at the end facing the shoulder is D7, satisfying: D7 > D5.

10. The battery according to claim 7, characterized in that, A support ring is provided at the end of the bracket away from the positive electrode, and the support ring extends along the circumference of the body.

11. The battery according to claim 10, characterized in that, There are multiple support rings, and the multiple support rings are arranged at radial intervals along the body; And / or, the distance between the end face of the support ring facing away from the positive electrode and the end face of the bracket facing away from the positive electrode is H2, satisfying: 0.1mm≤H2≤0.5mm.

12. The battery according to claim 7, characterized in that, A recessed platform is provided on the end face of the bracket opposite to the positive electrode, and the mating hole penetrates the bottom wall of the recessed platform; And / or, a boss is provided on the end face of the bracket near the positive electrode, and the boss is arranged around the axis of the body.

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