Lower plastic and secondary battery

Abstract

The utility model provides a lower plastic and secondary battery, lower plastic includes lower plastic body, first pin installation groove, second pin installation groove and raise portion, raise portion is connected in the groove bottom of first pin installation groove, the thickness of raise portion is less than the groove depth of first pin installation groove, the distance of raise portion with the slot mouth of first pin installation groove is less than the groove depth of second pin installation groove, the end face of raise portion towards the slot mouth of first pin installation groove is connected with first pole post connecting section abuts. The utility model discloses set up raise portion in first pin installation groove, reduce the depth actually used for accommodating first pin in first pin installation groove, make first pole post connecting section also can be flush with the slot mouth of first pin installation groove, prevent the slot mouth edge of first pin installation groove from protruding to the side of first pole post connecting section towards electric core subassembly, prevent the edge of slot mouth of first pin installation groove from bruising the pole piece of electric core subassembly under the vibration impact of battery, improve the security of secondary battery.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a plastic and a secondary battery. Background Technology

[0002] Square batteries are a commonly used structure for lithium-ion power batteries. They generally include a casing, cell assembly, cover plate, and lower plastic layer. The cell assembly is housed inside the casing, the cover plate covers the opening of the casing, and the lower plastic layer is located between the cover plate and the cell assembly for insulation. The cover plate has positive and negative terminals. The cell assembly connects to the positive terminal via a positive pin and to the negative terminal via a negative pin. The lower plastic layer has a positive pin mounting slot for accommodating the positive pin and a negative pin mounting slot for accommodating the negative pin, making the battery structure more compact.

[0003] In existing technologies, the positive and negative leads may be made of different materials. Since different materials have different resistivities, their current-carrying capacity differs even when the material thickness is the same. That is, even with the same thickness, the positive and negative leads will have different current-carrying capacities. To avoid over-design, designers will make the leads made of materials with lower resistivity thinner. For example, the positive lead may be made of aluminum, and the negative lead of copper. Copper has a lower resistivity than aluminum, and at the same thickness, copper has a greater current-carrying capacity than aluminum. Therefore, in battery current-carrying design, to avoid over-designing the negative copper lead, it is generally designed to be thinner than the positive aluminum lead.

[0004] However, currently the positive and negative pin mounting slots have the same depth. Therefore, the thickness of a thinner pin will be less than the depth of the corresponding pin mounting slot, causing the slot opening area to protrude beyond the pin. During battery vibration, the edge of the pin mounting slot opening may collide with and damage the electrode plates of the cell assembly, causing electrode powder to fall off, which in turn leads to internal corrosion of the casing and causes battery safety issues. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the defect that in the prior art, the depth of the positive electrode pin mounting groove and the negative electrode pin mounting groove on the lower plastic is the same. When the thickness of the positive electrode pin and the negative electrode pin is different, the edge of the pin mounting groove of the thinner pin is easy to damage the electrode sheet of the cell assembly, which affects the battery safety. The present invention provides a lower plastic and a secondary battery.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] A lower plastic body includes a lower plastic body, a first pin mounting groove, a second pin mounting groove, and a raised part;

[0008] The first pin mounting slot and the second pin mounting slot are located at both ends of the lower plastic body along the length direction of the lower plastic body. The first pin mounting slot and the second pin mounting slot are recessed from the same end face of the lower plastic body in the thickness direction of the lower plastic body toward the interior of the lower plastic body. The first pin mounting slot is used to accommodate the first pole post connection section of the first pin, and the second pin mounting slot is used to accommodate the second pole post connection section of the second pin.

[0009] The raised part is connected to the bottom of the first pin mounting groove. The thickness of the raised part in the lower plastic thickness direction is less than the groove depth of the first pin mounting groove. The distance between the raised part and the groove opening of the first pin mounting groove in the lower plastic thickness direction is less than the groove depth of the second pin mounting groove. One end face of the raised part facing the groove opening of the first pin mounting groove is used to abut against the first pole post connection section.

[0010] In this solution, by setting a raised portion in the first pin mounting groove, the actual depth of the first pin mounting groove used to accommodate the first pin is reduced. This ensures that even when the thickness of the first electrode connection section of the first pin is less than the groove depth of the first pin mounting groove, the first electrode connection section can still be flush with the groove opening of the first pin mounting groove. This prevents the groove opening edge of the first pin mounting groove from protruding beyond the side of the first electrode connection section facing the cell assembly. It also prevents the groove opening edge of the first pin mounting groove from damaging the electrode plates of the cell assembly under vibration and impact, thereby avoiding a series of safety problems such as electrode powder shedding, internal short circuits, and shell corrosion, and improving the safety of the secondary battery.

[0011] Preferably, the raised portion includes a plurality of raised ribs, which extend within a first plane and are all fixed to the bottom of the first pin mounting groove; wherein the first plane is parallel to the plane enclosed by the length and width directions of the lower plastic.

[0012] In this design, a raised rib structure is used instead of a solid boss. This provides sufficient support strength and area while minimizing material usage, reducing costs and the weight of the lower plastic component. Multiple raised ribs extend within the first plane and are fixed to the bottom of the first pin mounting slot, collectively forming a stable support plane that can evenly bear the pressure and vibration stress transmitted from the first pin, preventing local deformation or collapse of the first pin.

[0013] Preferably, the lower plastic also includes a first electrode mounting hole, which penetrates the bottom of the first pin mounting groove;

[0014] The plurality of lifting ribs include a first lifting rib, a plurality of second lifting ribs and a plurality of third lifting ribs; the first lifting rib is annular and is arranged around the first pole post mounting hole; the second lifting ribs extend along the length direction of the lower plastic and the third lifting ribs extend along the width direction of the lower plastic.

[0015] In this design, the above-mentioned configuration enables the raised portion to provide support for the first pin at multiple locations, more effectively distributing the load of the first pin to various areas of the entire first pin mounting slot and reducing stress concentration.

[0016] Preferably, the lower plastic meets one or more of the following conditions:

[0017] a1. The first lifting rib intersects with at least one second lifting rib;

[0018] b1. The first lifting rib intersects with at least one of the third lifting ribs;

[0019] c1. At least one of the second lifting ribs intersects with at least one of the third lifting ribs.

[0020] In this scheme, by connecting the raised ribs to each other, the independent raised ribs are connected into an integrated mesh frame structure, which enhances the overall structural rigidity and deformation resistance of the raised part, and can more effectively resist vibration and impact from all directions.

[0021] Preferably, the lower plastic meets one or more of the following conditions:

[0022] a2. At least one end of the second lifting rib extends to the groove wall of the first pin mounting groove in the length direction of the lower plastic. The lower plastic also includes a first reinforcing member, which is disposed on the groove wall of the first pin mounting groove in the length direction of the lower plastic. The first reinforcing member intersects with the second lifting rib.

[0023] b2. At least one end of the third lifting rib extends to the groove wall of the first pin mounting groove in the width direction of the lower plastic. The lower plastic also includes a second reinforcing member, which is disposed on the groove wall of the first pin mounting groove in the width direction of the lower plastic and intersects with the third lifting rib.

[0024] In this design, the above-mentioned configuration effectively transfers and distributes the load borne by the raised part to the groove wall of the first pin mounting groove, thus avoiding stress concentration.

[0025] Preferably, the lower plastic also includes a first anti-rotation part, a second anti-rotation part, and a second pole mounting hole. The first anti-rotation part and the second anti-rotation part are both connected to the lower plastic body, and the second pole mounting hole penetrates the bottom of the second pin mounting groove.

[0026] The first pole post is provided with a third anti-rotation part that cooperates with the first anti-rotation part. The first anti-rotation part and the third anti-rotation part cooperate to restrict the lower plastic body from rotating around the axis of the first pole post. The second pole post is provided with a fourth anti-rotation part that cooperates with the second anti-rotation part. The second anti-rotation part and the fourth anti-rotation part cooperate to restrict the lower plastic body from rotating around the axis of the second pole post.

[0027] In this design, the rotational freedom of the lower plastic component around the first and third pole axis, as well as around the second pole axis, is restricted through the cooperation between the first and third anti-rotation parts and the second anti-rotation part. This ensures that the lower plastic component remains centered during the cell insertion process, preventing interference and scratches with the casing caused by torsion.

[0028] Preferably, the lower plastic meets one or more of the following conditions:

[0029] a3. The first anti-rotation part is a first protrusion provided at the bottom of the first pin mounting groove. The first protrusion extends from the bottom of the first pin mounting groove along the lower plastic thickness direction toward the opening of the first pin mounting groove.

[0030] The third anti-rotation part is a first groove provided on the first pole post, the first protrusion is accommodated in the first groove, and the two ends of the first protrusion along the circumferential direction of the mounting hole of the first pole post abut against the groove wall of the first groove.

[0031] b3. The second anti-rotation part is a second protrusion provided at the bottom of the second pin mounting groove. The second protrusion extends from the bottom of the second pin mounting groove along the lower plastic thickness direction toward the opening of the second pin mounting groove.

[0032] The fourth anti-rotation part is a second groove provided on the second pole post, and the second protrusion is accommodated in the second groove. The two ends of the second protrusion along the circumferential direction of the mounting hole of the second pole post abut against the groove wall of the second groove.

[0033] This design employs a protrusion-groove mating method, resulting in a simple structure, convenient processing, and low cost. The contact between the protrusion and the groove wall provides direct and effective rotational limiting, with a clear and reliable anti-rotation effect. During assembly, the protrusion and groove mating has a self-positioning function, facilitating quick and accurate installation of the lower plastic parts and improving production efficiency.

[0034] Preferably, when the first anti-rotation part is a first protrusion located at the bottom of the first pin mounting groove, the radial inner side of the first lifting rib and the hole wall of the first pole mounting hole are spaced apart radially in the first pole mounting hole, the first protrusion is located within the space, and the first protrusion is connected to the radial inner side of the first lifting rib.

[0035] In this design, the above-mentioned arrangement ensures that the first protrusion is no longer an isolated unit, but is reinforced and supported by high-strength lifting ribs, preventing the first protrusion from breaking or being damaged when subjected to torsional torque, thus ensuring the durability and reliability of the anti-rotation function.

[0036] A secondary battery includes a first pin, a second pin, and a lower plastic as described above;

[0037] The first terminal connection segment of the first pin is accommodated in the mounting slot of the first pin, and the second terminal connection segment of the second pin is accommodated in the mounting slot of the second pin. The thickness of the first terminal connection segment is less than the thickness of the second terminal connection segment.

[0038] The end of the first pole connecting segment facing the bottom of the first pin mounting slot abuts against the raised portion, and the end of the first pole connecting segment away from the bottom of the first pin mounting slot is flush with the opening of the first pin mounting slot; the end of the second pole connecting segment facing the bottom of the second pin mounting slot abuts against the bottom of the second pin mounting slot, and the end of the second pole connecting segment away from the bottom of the second pin mounting slot is flush with the opening of the second pin mounting slot.

[0039] In this solution, the above-mentioned arrangement ensures that the edges of the first pin mounting groove and the second pin mounting groove do not protrude beyond the corresponding pins. This prevents the edges of the first pin mounting groove and the second pin mounting groove from damaging the electrode plates of the cell assembly under vibration and impact, thereby avoiding a series of safety problems such as electrode powder shedding, internal short circuits, and shell corrosion, and improving the safety of the secondary battery.

[0040] Preferably, the first electrode post includes a first electrode post body and a first extension, the first extension extending radially from the outer peripheral surface of the first electrode post body toward the outside of the first electrode post body, and the first extension is accommodated in the first pin mounting slot.

[0041] The secondary battery also includes a cover plate and a first sealing ring. The cover plate is disposed on the side of the lower plastic away from the port of the first pin mounting groove in its thickness direction. The first sealing ring includes a first sealing section, and the two ends of the first sealing section in the thickness direction of the lower plastic abut against the cover plate and the first extension, respectively.

[0042] The distance between the end face of the lower plastic facing the cover plate and the bottom of the first pin mounting groove is defined as D, the thickness of the first sealing section is t, and the compression ratio of the first sealing section in the thickness direction of the lower plastic is p; where D = tt * p.

[0043] In this design, the above-mentioned configuration ensures reliable airtightness between the first terminal and the cover plate, while avoiding damage to the first sealing ring due to excessive compression or sealing failure due to insufficient compression, thereby improving the safety of the secondary battery.

[0044] The positive and progressive effects of this utility model are as follows: By setting a raised part in the first pin mounting groove, the actual depth of the first pin mounting groove used to accommodate the first pin is reduced. This allows the first electrode connection section of the first pin to be flush with the groove opening even when the thickness of the first electrode connection section is less than the groove depth of the first pin mounting groove. This prevents the groove opening edge of the first pin mounting groove from protruding from the side of the first electrode connection section facing the cell assembly. It also prevents the groove opening edge of the first pin mounting groove from damaging the electrode of the cell assembly under vibration and impact, thereby avoiding a series of safety problems such as electrode powder shedding, internal short circuits, and shell corrosion, and improving the safety of the secondary battery. Attached Figure Description

[0045] Figure 1 This is an exploded view of a portion of the structure of a secondary battery according to an embodiment of the present invention.

[0046] Figure 2 This is another exploded view of a portion of the structure of a secondary battery according to an embodiment of the present invention.

[0047] Figure 3 This is a side view of a portion of the structure of a secondary battery according to an embodiment of the present invention.

[0048] Figure 4 This is a schematic diagram of the internal structure of a secondary battery according to an embodiment of the present invention.

[0049] Figure 5 This is a schematic diagram of the structure of the first pole post and the lower plastic part in one embodiment of the present invention.

[0050] Figure 6 This is a schematic diagram of the structure of the second pole post and the lower plastic part in one embodiment of the present invention.

[0051] Figure 7 This is a three-dimensional structural diagram of the lower plastic material according to an embodiment of the present invention.

[0052] Figure 8 This is a three-dimensional structural diagram of the first pole post according to an embodiment of the present invention.

[0053] Figure 9 This is a three-dimensional structural diagram of the second pole of an embodiment of the present invention.

[0054] Figure 10 This is a schematic diagram of the structure of the lower plastic, the first electrode post, and the second electrode post in accordance with an embodiment of the present invention.

[0055] Figure 11 for Figure 10 Enlarged view of part A.

[0056] Explanation of reference numerals in the attached figures:

[0057] Cover plate 1, first negative electrode through hole 11, first positive electrode through hole 12, lower plastic 2, first electrode mounting hole 21, second electrode mounting hole 22, lower plastic body 23, first pin mounting groove 24, second pin mounting groove 25, raised part 26, first raised rib 261, second raised rib 262, third raised rib 263, first protective part 27, second protective part 28, second reinforcing member 29, first electrode 31, first electrode body 311, first extension part 312, second electrode 32, second electrode body 321, second extension part 322, first riveting block 41, second riveting block 42, first upper plastic 51, second negative electrode through hole 2 Perforation 511, second upper plastic 52, second positive electrode through hole 521, first sealing ring 61, third negative electrode through hole 611, first sealing section 612, second sealing section 613, second sealing ring 62, third positive electrode through hole 621, third sealing section 622, fourth sealing section 623, first pin 7, first pole post connecting section 71, first pole tab connecting section 72, first pin body 73, first pin adhesive 74, second pin 8, second pole post connecting section 81, second pole tab connecting section 82, second pin body 83, second pin adhesive 84, first protrusion 91, first groove 92, second protrusion 93, second groove 94. Detailed Implementation

[0058] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0059] like Figures 1-6 As shown, this embodiment discloses a secondary battery, including a casing, a cover plate 1, a cell assembly, a lower plastic 2, a first terminal post 31, a second terminal post 32, a first riveting block 41, a second riveting block 42, a first upper plastic 51, a second upper plastic 52, a first sealing ring 61, a second sealing ring 62, a first pin 7, and a second pin 8.

[0060] like Figures 1-6 As shown, the battery cell assembly is located inside the housing, and the cover plate 1 is placed over the opening of the housing to form a sealed receiving space.

[0061] The lower plastic 2 is located at the end of the cover plate 1 facing the receiving space. The first riveting block 41, the second riveting block 42, the first upper plastic 51, and the second upper plastic 52 are all located at the end of the cover plate 1 facing the external space of the secondary battery. The first terminal 31 and the second terminal 32 both pass through the cover plate 1. The ends of the first terminal 31 and the second terminal 32 facing the receiving space are electrically connected to the cell assembly through the first pin 7 and the second pin 8, respectively. The ends of the first terminal 31 and the second terminal 32 facing the external space of the secondary battery are riveted and fixed to the first riveting block 41 and the second riveting block 42, respectively, for connection with electrical equipment. The first sealing ring 61 is used to achieve insulation between the first terminal 31 and the cover plate 1, and the second sealing ring 62 is used to achieve insulation between the second terminal 32 and the cover plate 1.

[0062] Specifically, in this embodiment, the first terminal 31 is the negative terminal, and the second terminal 32 is the positive terminal. For example... Figure 8 and Figure 9 As shown, in this embodiment, the first terminal 31 and the second terminal 32 have the same shape, but their materials are different. The material of the end of the first terminal 31 used to connect to the cell assembly and the material of the first pin 7 connected to the first terminal 31 are the same, both being copper. The material of the end of the second terminal 32 used to connect to the cell assembly and the material of the second pin 8 connected to the second terminal 32 are the same, both being aluminum. Since the resistivity of copper is lower than that of aluminum, copper has a greater current-carrying capacity than aluminum at the same thickness. Therefore, in this embodiment, the thickness of the first pin 7 is less than the thickness of the second pin 8 to ensure that the current-carrying capacities of the first pin 7 and the second pin 8 are approximately the same.

[0063] In other alternative implementations, the materials for the positive and negative terminals can also be other conventional terminal materials. If the resistivity of the positive terminal material is less than that of the negative terminal material, then in this state, the first terminal 31 is the positive terminal and the second terminal 32 is the negative terminal.

[0064] like Figure 1 and Figure 2 As shown, the cover plate 1 is provided with a first negative electrode through hole 11 and a first positive electrode through hole 12; the first upper plastic 51 is provided with a second negative electrode through hole 511; the second upper plastic 52 is provided with a second positive electrode through hole 521; the first sealing ring 61 is provided with a third negative electrode through hole 611; the second sealing ring 62 is provided with a third positive electrode through hole 621; the lower plastic 2 is provided with a first electrode post 31 mounting hole 21 and a second electrode post 32 mounting hole 22. The first positive electrode through hole 12, the second positive electrode through hole 521, the third positive electrode through hole 621, the first negative electrode through hole 11, the second negative electrode through hole 511, the third negative electrode through hole 611, the first electrode post 31 mounting hole 21, and the second electrode post 32 mounting hole 22 are all located in the thickness direction of the lower plastic 2. Figure 1The two ends of the lower plastic 2 (in the Z direction) are open to allow the corresponding first electrode 31 and second electrode 32 to pass through. The ends of the first electrode 31 and the second electrode 32 facing the external space of the secondary battery are respectively riveted and fixed to the first riveting block 41 and the second riveting block 42 to increase the connection surface with the electrical equipment. The thickness direction of the lower plastic 2 is the axial direction of the first electrode 31 and the second electrode 32.

[0065] The first upper plastic 51 and the second upper plastic 52 are disposed on the end face of the cover plate 1 facing the external space of the secondary battery. The first upper plastic 51 is axially sandwiched between the cover plate 1 and the first riveting block 41 in the first electrode post 31, and the second upper plastic 52 is axially sandwiched between the cover plate 1 and the second riveting block 42 in the second electrode post 32. The first sealing ring 61 is sleeved on the outer periphery of the first electrode post 31. One end of the first sealing ring 61 extends into the first negative electrode through hole 11 and abuts against the end face of the first upper plastic 51 (or the first riveting block 41) facing the receiving space. The other end of the first sealing ring 61 is axially sandwiched between the cover plate 1 and the first electrode post 31 in the first electrode post 31, thereby achieving insulation between the first electrode post 31 and the first riveting block 41 and the cover plate 1. The second sealing ring 62 is sleeved on the outer periphery of the second pole post 32. One end of the second sealing ring 62 extends into the first positive electrode through hole 12 and abuts against the end face of the second upper plastic 52 (or the second riveting block 42) facing the receiving space. The other end of the second sealing ring 62 is clamped between the cover plate 1 body and the second pole post 32 in the axial direction of the second pole post 32, thereby achieving insulation between the second pole post 32 and the second riveting block 42 and the cover plate 1 body.

[0066] Specifically, such as Figures 1-6As shown, the first sealing ring 61 includes a first sealing section 612 and a second sealing section 613, which are coaxially arranged. The first sealing section 612 is located on the side of the second sealing section 613 facing the receiving space, and the diameter of the first sealing section 612 is larger than the diameter of the second sealing section 613. The first pole post 31 includes a first pole post body 311 and a first extension 312. The first extension 312 is located on the side of the first pole post body 311 facing the receiving space. The first extension 312 extends radially from the outer peripheral surface of the first pole post body 311 toward the outside of the first pole post body 311. The first sealing section 612 is at least partially located in the mounting hole 21 of the first pole post 31. The two ends of the first sealing section 612 in the thickness direction of the lower plastic 2 abut against the cover plate 1 and the first extension 312, respectively. The second sealing section 613 extends into the first negative electrode through hole 11. The second sealing ring 62 includes a third sealing section 622 and a fourth sealing section 623, which are coaxially arranged. The third sealing section 622 is located on the side of the fourth sealing section 623 facing the receiving space, and the diameter of the third sealing section 622 is larger than the diameter of the fourth sealing section 623. The second pole post 32 includes a second pole post body 321 and a second extension 322. The second extension 322 is located on the side of the second pole post body 321 facing the receiving space and extends radially from the outer peripheral surface of the second pole post body 321 toward the outside of the second pole post body 321. The third sealing section 622 is at least partially located in the mounting hole 22 of the second pole post 32. The two ends of the third sealing section 622 in the thickness direction of the lower plastic 2 abut against the cover plate 1 and the second extension 322, respectively. The fourth sealing section 623 extends into the first positive electrode through hole 12.

[0067] like Figure 1 and Figure 2As shown, the first pin 7 includes a first terminal connection section 71 and a first tab connection section 72. The first terminal connection section 71 is used to connect with the first terminal 31, and the first tab connection section 72 is used for connecting the negative tab of the battery cell assembly. The first pin 7 includes a first pin body 73 and a first pin adhesive 74 in its thickness direction. The first pin adhesive 74 is located on the side of the first pin body 73 facing the battery cell assembly to fix the position of the first pin 7 relative to the battery cell assembly. Both the first terminal connection section 71 and the first tab connection section 72 include a portion of the first pin body 73 and the first pin adhesive 74. The second pin 8 includes a second terminal connection section 81 and a second tab connection section 82. The second terminal connection section 81 is used to connect with the second terminal 32, and the second tab connection section 82 is used for connecting the positive tab of the battery cell assembly. The second pin 8 includes a second pin body 83 and a second pin adhesive 84 in its thickness direction. The second pin adhesive 84 is disposed on the side of the second pin body 83 facing the cell assembly to fix the position of the second pin 8 relative to the cell assembly. The second terminal post connection section 81 and the second terminal tab connection section 82 both include a portion of the second pin body 83 and the second pin adhesive 84.

[0068] like Figures 1-7 As shown, the lower plastic 2 includes a lower plastic body 23, a first pin 7 mounting groove 24, a second pin 8 mounting groove 25, a raised part 26, a first protective part 27, and a second protective part 28.

[0069] like Figure 2 , Figures 5-7 As shown, the first pin 7 mounting slot 24 and the second pin 8 mounting slot 25 are located along the length of the lower plastic body 23 ( Figure 1 At both ends (in the X direction), the first pin 7 mounting groove 24 and the second pin 8 mounting groove 25 are recessed from the same end face of the lower plastic body 23 in the thickness direction of the lower plastic body 2, facing inwards towards the interior of the lower plastic body 23. The first electrode connection section 71 of the first pin 7 is accommodated in the first pin 7 mounting groove 24, and the second electrode connection section 81 of the second pin 8 is accommodated in the second pin 8 mounting groove 25. The mounting hole 21 of the first electrode 31 penetrates through the bottom of the first pin 7 mounting groove 24, and the mounting hole 22 of the second electrode 32 penetrates through the bottom of the second pin 8 mounting groove 25. The first pin 7 mounting groove 24 and the second pin 8 mounting groove 25 can reduce the extra space occupied by the first pin 7 and the second pin 8 in the thickness direction of the lower plastic body 2, making the structure of the secondary battery more compact.

[0070] The first protective part 27 and the second protective part 28 are located at both ends of the lower plastic body 23 along the length of the lower plastic body 2. The first protective part 27 and the second protective part 28 extend from the lower plastic body 23 toward the battery cell assembly. The first terminal connection section 71 and the second terminal connection section 81 are located between the first protective part 27 and the second protective part 28. The first protective part 27 and the second protective part 28 are used to isolate the housing and the first pin 7 and the second pin 8.

[0071] like Figure 2 , Figures 5-7 As shown, the raised part 26 is connected to the bottom of the first pin 7 mounting groove 24. The thickness of the raised part 26 in the thickness direction of the lower plastic 2 is less than the depth of the first pin 7 mounting groove 24. The distance between the raised part 26 and the opening of the first pin 7 mounting groove 24 in the thickness direction of the lower plastic 2 is less than the depth of the second pin 8 mounting groove 25. The end of the first pole post connecting section 71 facing the bottom of the first pin 7 mounting groove 24 abuts against the raised part 26, and the end of the first pole post connecting section 71 away from the bottom of the first pin 7 mounting groove 24 is flush with the opening of the first pin 7 mounting groove 24. The second pole post 32 mounting groove does not have a raised part 26. The end of the second pole post connecting section 81 facing the bottom of the second pin 8 mounting groove 25 abuts against the bottom of the second pin 8 mounting groove 25, and the end of the second pole post connecting section 81 away from the bottom of the second pin 8 mounting groove 25 is flush with the opening of the second pin 8 mounting groove 25.

[0072] Since the thickness of the first pin 7 is less than the thickness of the second pin 8, and the depths of the mounting groove 24 for the first pin 7 and the mounting groove 25 for the second pin 8 are the same, this embodiment reduces the actual depth of the mounting groove 24 for accommodating the first pin 7 by providing a raised portion 26 within the mounting groove 24. This ensures that even when the thickness of the first terminal connecting section 71 of the first pin 7 is less than the depth of the mounting groove 24, the first terminal connecting section 71 can still be flush with the opening of the mounting groove 24, thus preventing the edge of the opening of the mounting groove 24 from protruding beyond the side of the first terminal connecting section 71 facing the cell assembly. Because the second pin 8 is thicker, the raised portion 26 is not required within the mounting groove 32, thus preventing the edge of the mounting groove 25 from protruding beyond the side of the second terminal connecting section 81 facing the cell assembly. To prevent the edges of the first pin 7 mounting groove 24 and the second pin 8 mounting groove 25 from damaging the electrode plates of the cell assembly under vibration and impact, thereby avoiding a series of safety problems such as electrode powder shedding, internal short circuits and shell corrosion, and improving the safety of the secondary battery.

[0073] Wherein, the thickness of the raised part 26 in the thickness direction of the lower plastic 2 is defined as A, the thickness of the lower plastic body 23 in the thickness direction of the lower plastic 2 is defined as B, the distance between the end face of the lower plastic 2 facing the cover plate 1 and the bottom of the groove of the first pin 7 mounting groove 24 is defined as D, the thickness of the first pin body 73 in the thickness direction of the lower plastic 2 is defined as C, the thickness of the first pin adhesive 74 in the thickness direction of the lower plastic 2 is defined as E, the thickness of the first sealing section 612 in the thickness direction of the lower plastic 2 is defined as t, and the compression ratio of the first sealing section 612 in the thickness direction of the lower plastic 2 is defined as p.

[0074] The following conditions must be met: A=BDCE; D=tt*p, to ensure reliable airtightness between the first terminal 31 and the cover plate 1, and to avoid damage to the sealing ring due to excessive compression or failure of the seal due to insufficient compression, thereby improving the safety of the secondary battery.

[0075] The compression ratio of the first sealing section 612 in the thickness direction of the lower plastic 2 depends on its own material, and is generally 15% to 45%.

[0076] Furthermore, such as Figure 7 As shown, in this embodiment, multiple lifting ribs extend within a first plane (parallel to the plane enclosed by the length and width directions of the lower plastic 2) and are all fixed to the bottom of the mounting groove 24 of the first pin 7. Specifically, the multiple lifting ribs include a first lifting rib 261, several second lifting ribs 262, and several third lifting ribs 263. The first lifting rib 261 is annular and surrounds the mounting hole 21 of the first pole post 31. The second lifting ribs 262 extend along the length direction of the lower plastic 2, and the third lifting ribs 263 extend along the width direction of the lower plastic 2. Figure 1 (Extends in the Y direction).

[0077] This embodiment employs a raised rib structure instead of a solid boss, providing sufficient support strength and area while minimizing material usage, reducing cost and the weight of the lower plastic 2. Multiple raised ribs extend within the first plane and are fixed to the bottom of the mounting groove 24 of the first pin 7, collectively forming a stable support plane. This provides support to the first pin 7 at multiple locations, evenly bearing the pressure and vibration stress transmitted from the first pin 7. It more effectively distributes the load of the first pin 7 to various areas of the mounting groove 24, reducing stress concentration and preventing local deformation or collapse of the first pin 7.

[0078] This embodiment does not specify the number of the second raising rib 262 and the third raising rib 263; the specific number can be designed according to actual needs.

[0079] In other alternative embodiments, the raised part 26 may not simultaneously include the first raised rib 261, the second raised rib 262 and the third raised rib 263, and the specific combination can be made according to the needs.

[0080] Furthermore, such as Figure 7 As shown, in this embodiment, the first raising rib 261 intersects with the second raising rib 262, the first raising rib 261 intersects with one of the third raising ribs 263, and the second raising rib 262 intersects with another third raising rib 263, thereby connecting the raising ribs to each other and forming an integrated mesh frame structure, which enhances the overall structural rigidity and deformation resistance of the raised part 26, and can more effectively resist vibrations and impacts from all directions.

[0081] In other alternative embodiments, when the number of second lifting ribs 262 and third lifting ribs 263 is greater, the first lifting rib 261 may intersect with multiple second lifting ribs 262 and / or multiple third lifting ribs 263 simultaneously, a single second lifting rib 262 may intersect with multiple third lifting ribs 263, or a single third lifting rib 263 may intersect with multiple second lifting ribs 262.

[0082] In other alternative implementations, the lifting ribs may not be directly connected.

[0083] Furthermore, such as Figure 7 As shown, the lower plastic 2 also includes a second reinforcing member 29. The third lifting rib 263 extends from both ends of the lower plastic 2 in the width direction to the groove wall of the first pin 7 mounting groove 24 on the corresponding side. The second reinforcing member 29 is disposed on the groove wall of the first pin 7 mounting groove 24 in the width direction of the lower plastic 2. The second reinforcing member 29 intersects with the third lifting rib 263 to effectively transfer and distribute the load borne by the raised part 26 to the groove wall of the first pin 7 mounting groove 24, so as to avoid stress concentration.

[0084] In other alternative implementations, the second reinforcing member 29 may be provided only at one end of the third raising rib 263.

[0085] In other alternative embodiments, the lower plastic 2 further includes a first reinforcing member, and at least one end of the second lifting rib 262 extends to the groove wall of the first pin 7 mounting groove 24 in the length direction of the lower plastic 2. The first reinforcing member is disposed on the groove wall of the first pin 7 mounting groove 24 in the length direction of the lower plastic 2. The first reinforcing member intersects with the second lifting rib 262, thereby effectively transferring and distributing the load borne by the raised part 26 to the groove wall of the first pin 7 mounting groove 24 to avoid stress concentration.

[0086] like Figures 7-11As shown, the lower plastic 2 also includes a first anti-rotation part and a second anti-rotation part, both of which are connected to the lower plastic body 23. The first electrode post 31 has a third anti-rotation part that cooperates with the first anti-rotation part. The first and third anti-rotation parts cooperate to restrict the rotation of the lower plastic body 23 around the axis of the first electrode post 31. The second electrode post 32 has a fourth anti-rotation part that cooperates with the second anti-rotation part. The second and fourth anti-rotation parts cooperate to restrict the rotation of the lower plastic body 23 around the axis of the second electrode post 32. In this embodiment, the cooperation between the first and third anti-rotation parts, and between the second and fourth anti-rotation parts, restricts the rotational freedom of the lower plastic 2 around the axis of the first electrode post 31 and around the axis of the second electrode post 32. This ensures that the lower plastic 2 is centered during the insertion of the battery cell into the casing, avoiding interference and scratches with the casing caused by torsion.

[0087] Specifically, such as Figures 7-11 As shown, the first anti-rotation part is a first protrusion 91 located at the bottom of the mounting groove 24 of the first pin 7. The first protrusion 91 extends from the bottom of the mounting groove 24 of the first pin 7 along the thickness direction of the lower plastic 2 toward the opening of the mounting groove 24 of the first pin 7. The third anti-rotation part is a first groove 92 located on the first extension 312. The first extension 312 is accommodated in the mounting groove 24 of the first pin 7, and the first protrusion 91 is accommodated in the first groove 92. The two ends of the first protrusion 91 along the circumferential direction of the mounting hole 21 of the first pole post 31 abut against the groove wall of the first groove 92, thereby restricting the rotation of the lower plastic body 23 around the axis of the first pole post 31. The second anti-rotation part is a second protrusion 93 located at the bottom of the mounting groove 25 of the second pin 8. The second protrusion 93 extends from the bottom of the mounting groove 25 of the second pin 8 along the thickness direction of the lower plastic 2 toward the opening of the mounting groove 25 of the second pin 8. The fourth anti-rotation part is a second groove 94 provided on the second extension 322. The second extension 322 is accommodated in the mounting groove 25 of the second pin 8. The second protrusion 93 is accommodated in the second groove 94. The two ends of the second protrusion 93 along the circumferential direction of the mounting hole 22 of the second pole post 32 abut against the groove wall of the second groove 94, thereby restricting the rotation of the lower plastic body 23 around the axis of the second pole post 32.

[0088] The design employs a protrusion-groove mating system, resulting in a simple structure, convenient processing, and low cost. The contact between the protrusion and the groove wall provides direct and effective rotational limiting, offering a clear and reliable anti-rotation effect. During assembly, the protrusion and groove mating system has a self-positioning function, facilitating quick and accurate installation of the lower plastic component 2, thus improving production efficiency.

[0089] In this embodiment, the first groove 92 and the second groove 94 are connected at both ends in the thickness direction of the lower plastic 2. In other alternative embodiments, the first groove 92 and the second groove 94 may be connected at the end away from the receiving space in the thickness direction of the lower plastic 2, and closed at the end facing the receiving space.

[0090] In other alternative implementations, other structures capable of achieving the aforementioned anti-rotation function may also be used.

[0091] Furthermore, such as Figure 7 As shown, the radial inner side of the first lifting rib 261 and the hole wall of the first pole post 31 mounting hole 21 are spaced in the radial direction of the first pole post 31 mounting hole 21. The first protrusion 91 is located within the space and is connected to the radial inner side of the first lifting rib 261 so that the first protrusion 91 is no longer an isolated unit, but is reinforced and supported by a high-strength lifting rib, preventing the first protrusion 91 from breaking or being damaged when subjected to torsional torque, thus ensuring the durability and reliability of the anti-rotation function.

[0092] In other alternative embodiments, the first protrusion 91 and the raised portion 26 may also be provided independently of each other.

[0093] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship of the device or component shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0094] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A type of plastic, characterized in that, It includes a lower plastic body (23), a first pin mounting groove (24), a second pin mounting groove (25), and a raised part (26); The first pin mounting groove (24) and the second pin mounting groove (25) are located at both ends of the lower plastic body (23) along the length direction of the lower plastic (2). The first pin mounting groove (24) and the second pin mounting groove (25) are recessed from the same end face of the lower plastic body (23) in the thickness direction of the lower plastic (2) toward the interior of the lower plastic body (23). The first pin mounting groove (24) is used to accommodate the first pole post connection section (71) of the first pin (7), and the second pin mounting groove (25) is used to accommodate the second pole post connection section (81) of the second pin (8). The raised part (26) is connected to the bottom of the first pin mounting groove (24). The thickness of the raised part (26) in the thickness direction of the lower plastic (2) is less than the depth of the first pin mounting groove (24). The distance between the raised part (26) and the opening of the first pin mounting groove (24) in the thickness direction of the lower plastic (2) is less than the depth of the second pin mounting groove (25). One end face of the raised part (26) facing the opening of the first pin mounting groove (24) is used to abut against the first pole post connecting section (71).

2. The lower plastic as described in claim 1, characterized in that, The raised part (26) includes a plurality of raised ribs, which extend in a first plane and are all fixed to the bottom of the first pin mounting groove (24); wherein the first plane is parallel to the plane enclosed by the length direction and the width direction of the lower plastic (2).

3. The lower plastic as described in claim 2, characterized in that, The lower plastic (2) also includes a first pole mounting hole (21), which penetrates the bottom of the first pin mounting groove (24); The plurality of lifting ribs include a first lifting rib (261), a plurality of second lifting ribs (262) and a plurality of third lifting ribs (263); the first lifting rib (261) is annular and is arranged around the first pole post mounting hole (21); the second lifting ribs (262) extend along the length direction of the lower plastic (2) and the third lifting ribs (263) extend along the width direction of the lower plastic (2).

4. The lower plastic as described in claim 3, characterized in that, The lower plastic (2) satisfies one or more of the following conditions: a1. The first lifting rib (261) intersects with at least one of the second lifting ribs (262); b1. The first lifting rib (261) intersects with at least one of the third lifting ribs (263); c1. At least one of the second lifting ribs (262) intersects with at least one of the third lifting ribs (263).

5. The lower plastic as described in claim 3, characterized in that, The lower plastic (2) satisfies one or more of the following conditions: a2. At least one end of the second lifting rib (262) extends to the groove wall of the first pin mounting groove (24) in the length direction of the lower plastic (2). The lower plastic (2) also includes a first reinforcing member, which is disposed on the groove wall of the first pin mounting groove (24) in the length direction of the lower plastic (2). The first reinforcing member intersects with the second lifting rib (262). b2. The third lifting rib (263) extends at least one end of the lower plastic (2) in the width direction to the groove wall of the first pin mounting groove (24). The lower plastic (2) also includes a second reinforcing member (29), which is disposed on the groove wall of the first pin mounting groove (24) in the width direction of the lower plastic (2). The second reinforcing member (29) intersects with the third lifting rib (263).

6. The lower plastic as described in claim 3, characterized in that, The lower plastic (2) also includes a first anti-rotation part, a second anti-rotation part, and a second pole mounting hole (22). The first anti-rotation part and the second anti-rotation part are both connected to the lower plastic body (23). The second pole mounting hole (22) penetrates the bottom of the second pin mounting groove (25). The first pole post (31) is provided with a third anti-rotation part that cooperates with the first anti-rotation part. The first anti-rotation part and the third anti-rotation part cooperate to restrict the lower plastic body (23) from rotating around the axis of the first pole post (31). The second pole post (32) is provided with a fourth anti-rotation part that cooperates with the second anti-rotation part. The second anti-rotation part and the fourth anti-rotation part cooperate to restrict the lower plastic body (23) from rotating around the axis of the second pole post (32).

7. The lower plastic as described in claim 6, characterized in that, The lower plastic (2) satisfies one or more of the following conditions: a3. The first anti-rotation part is a first protrusion (91) provided at the bottom of the first pin mounting groove (24). The first protrusion (91) extends from the bottom of the first pin mounting groove (24) along the thickness direction of the lower plastic (2) toward the opening of the first pin mounting groove (24). The third anti-rotation part is a first groove (92) provided on the first pole post (31), the first protrusion (91) is accommodated in the first groove (92), and the two ends of the first protrusion (91) along the circumferential direction of the first pole post mounting hole (21) abut against the groove wall of the first groove (92). b3. The second anti-rotation part is a second protrusion (93) provided at the bottom of the second pin mounting groove (25). The second protrusion (93) extends from the bottom of the second pin mounting groove (25) along the thickness direction of the lower plastic (2) toward the opening of the second pin mounting groove (25). The fourth anti-rotation part is a second groove (94) provided on the second pole post (32), and the second protrusion (93) is accommodated in the second groove (94). The two ends of the second protrusion (93) along the circumferential direction of the second pole post mounting hole (22) abut against the groove wall of the second groove (94).

8. The lower plastic as described in claim 7, characterized in that, When the first anti-rotation part is a first protrusion (91) provided at the bottom of the first pin mounting groove (24), the radial inner side of the first lifting rib (261) and the hole wall of the first pole mounting hole (21) are spaced in the radial direction of the first pole mounting hole (21), the first protrusion (91) is provided within the space, and the first protrusion (91) is connected to the radial inner side of the first lifting rib (261).

9. A secondary battery, characterized in that, Includes a first pin (7), a second pin (8), and a lower plastic (2) as described in any one of claims 1-8; The first pole connection segment (71) of the first pin (7) is accommodated in the first pin mounting slot (24), and the second pole connection segment (81) of the second pin (8) is accommodated in the second pin mounting slot (25). The thickness of the first pole connection segment (71) is less than the thickness of the second pole connection segment (81). The end of the first pole connecting section (71) facing the bottom of the first pin mounting groove (24) abuts against the raised part (26), and the end of the first pole connecting section (71) away from the bottom of the first pin mounting groove (24) is flush with the opening of the first pin mounting groove (24); the end of the second pole connecting section (81) facing the bottom of the second pin mounting groove (25) abuts against the bottom of the second pin mounting groove (25), and the end of the second pole connecting section (81) away from the bottom of the second pin mounting groove (25) is flush with the opening of the second pin mounting groove (25).

10. The secondary battery as described in claim 9, characterized in that, The first pole post (31) includes a first pole post body (311) and a first extension (312). The first extension (312) extends radially from the outer peripheral surface of the first pole post body (311) toward the outside of the first pole post body (311). The first extension (312) is accommodated in the first pin mounting groove (24). The secondary battery also includes a cover plate (1) and a first sealing ring (61). The cover plate (1) is disposed on the side of the lower plastic (2) away from the port of the first pin mounting groove (24) in its thickness direction. The first sealing ring (61) includes a first sealing section (612). The two ends of the first sealing section (612) in the thickness direction of the lower plastic (2) respectively abut against the cover plate (1) and the first extension (312). The distance between the end face of the lower plastic (2) facing the cover plate (1) and the bottom of the first pin mounting groove (24) is defined as D, the thickness of the first sealing section (612) is t, and the compression ratio of the first sealing section (612) in the thickness direction of the lower plastic (2) is p; where D = tt * p.

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