Battery cell cover plate assembly, battery cell and battery pack
By introducing a high-melting-point support structure into the cell cover assembly, the problem of the electrode assembly clogging the explosion-proof valve at high temperatures is solved, ensuring unobstructed venting channels for the cell and improving the cell's safety performance.
Patent Information
- Application Number
- CN202423225205.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2034-12-25
AI Technical Summary
When high temperatures are generated inside the battery cell, the lower plastic melts, causing the electrode assembly to clog the explosion-proof valve, affecting the venting and pressure relief effect, and reducing the safety performance of the battery cell.
Design a cell cover assembly comprising a cover, an explosion-proof valve, a plastic part, and a support structure. The melting point of the support structure is higher than that of the plastic part. A connected exhaust channel is formed between the support electrode assembly and the cover to ensure that the explosion-proof valve is not blocked under high temperature and high pressure gas.
Under the action of high temperature and high pressure gas, the support structure fixes the electrode group, keeps the exhaust channel of the explosion-proof valve unobstructed, and improves the safety performance of the battery cell.
Smart Images
Figure CN223828545U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field, concretely relates to electric core cover plate subassembly, electric core and battery package. BACKGROUND
[0002] Lithium ion battery has become the representative of modern high performance battery because of its high working voltage, high specific energy, large capacity, small self-discharge, good cycle performance, long service life, light weight and small size.
[0003] The long electric core lithium ion battery is usually designed to have the tab on both sides, and its structure comprises an electric core cover plate subassembly, a shell, a pole group, electrolyte and the like. The electric core cover plate subassembly is integrated with a pole, an explosion-proof valve and a liquid injection hole and other structural components. After the electric core cover plate subassembly and the shell are welded, a sealed space with certain mechanical strength is formed to protect the pole group. The tabs on both sides of the pole group are fixed by laser welding through the pole column base of the cover plate on both sides, so as to realize electrical connection. The length direction of the electric core is mainly fixed by the lower plastic insulating material inside the cover plate pressing on the pole group. The cover plate is integrated with an explosion-proof valve structure, which is mainly used for the directional discharge of high-temperature and high-pressure gas inside the battery when the battery appears thermal runaway due to internal short circuit, so as to improve the safety performance of the battery.
[0004] When high temperature occurs inside the electric core, the lower plastic will melt, resulting in the failure of the fixing effect of the pole group. The high-temperature and high-pressure gas inside the electric core will be discharged in the direction of the explosion-proof valve. Under the push of the high-temperature and high-pressure gas, the pole group will move towards the direction of the explosion-proof valve and block the explosion-proof valve, resulting in the blockage of the exhaust passage and affecting the exhaust pressure relief of the electric core, thereby reducing the safety performance of the electric core. UTILITY MODEL CONTENTS
[0005] Therefore, the utility model provides an electric core cover plate subassembly, an electric core and a battery package to solve the problem that the pole group blocks the explosion-proof valve when the lower plastic melts due to high temperature inside the electric core, thereby affecting the exhaust pressure relief.
[0006] In a first aspect, the utility model provides an electric core cover plate subassembly, which comprises a cover plate, an explosion-proof valve, a plastic part and at least one supporting structure. The cover plate is provided with an assembly hole, and the cover plate has a first surface facing the pole group of the electric core. The explosion-proof valve is arranged in the assembly hole. The plastic part is arranged on the first surface of the cover plate. The supporting structure is arranged between the cover plate and the plastic part and located on any side of the explosion-proof valve along the X direction. The melting point of the supporting structure is higher than that of the plastic part. The supporting structure is adapted to be supported between the pole group and the cover plate after the plastic part melts due to high temperature inside the electric core, so as to form an exhaust passage communicating with the explosion-proof valve. The height of the exhaust passage is H1, and 3mm≤H1≤6mm.
[0007] Beneficial effects: the electric core cover plate assembly provided by the utility model is provided with an explosion-proof valve protection structure, a support structure with a melting point higher than that of the plastic part is arranged, when high-temperature and high-pressure gas is generated in the electric core, the plastic part melts and fails, at this time, the support structure has not melted, the pole group will have a tendency to move towards the explosion-proof valve under the action of the high-temperature and high-pressure gas, at this time, the support structure can effectively support and fix the pole group, so that the pole group does not randomly move and shield the explosion-proof valve on the cover plate when the electric core is out of control, and the exhaust effect of the explosion-proof valve is affected, the support structure makes the pole group and the cover plate keep an exhaust passage in communication with the explosion-proof valve, ensures that the exhaust of the explosion-proof valve is not affected, and improves the safety performance of the electric core.
[0008] In an alternative embodiment, the support structure comprises a boss arranged on the first surface of the cover plate and a support frame connected with the boss, and the height of the support frame protruding from the side of the cover plate away from the first surface of the cover plate is the height of the exhaust passage.
[0009] In an alternative embodiment, the height H2 of the boss protruding from the first surface of the cover plate is 1.0mm≤H2≤2.0mm.
[0010] In an alternative embodiment, the support frame comprises a support plate and at least two support legs arranged on the edge of the support plate, the number and position of the bosses correspond to the number and position of the support legs, and each support leg is connected with one boss.
[0011] In an alternative embodiment, two support structures are arranged, and the two support structures are arranged on the two sides of the explosion-proof valve along the X direction.
[0012] In an alternative embodiment, the minimum distance between the boss near the explosion-proof valve and the explosion-proof valve along the X direction is L, and 5mm≤L≤8mm.
[0013] In an alternative embodiment, the support plate is provided with a plurality of exhaust through holes; and / or, the support leg, the support plate and the cover plate have an exhaust gap in communication with the exhaust passage.
[0014] In an alternative embodiment, among the boss and the support leg, one is provided with a plug-in protrusion, and the other is provided with a plug-in hole matched with the plug-in protrusion, the boss and the support leg are plugged in through the matching of the plug-in protrusion and the plug-in hole, and are welded and fixed.
[0015] In the second aspect, the utility model also provides an electric core, which comprises a shell, a pole group and the electric core cover plate assembly in the above technical solutions, the shell has an open end; the pole group is arranged in the shell; and the electric core cover plate assembly is arranged at the open end of the shell to encapsulate the pole group in the shell.
[0016] Beneficial effects: because the electric core comprises the electric core cover plate assembly, the same effects as the electric core cover plate assembly are achieved, and details are not repeated here.
[0017] In a third aspect, the utility model also provides a battery pack, including the electric core in above technical scheme.
[0018] Beneficial effect: because the battery pack includes the electric core, has the same effect with the electric core, here no longer repeat. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the specific embodiment of the utility model or the technical scheme in prior art, the following will be briefly introduced the drawing needed to be used in the specific embodiment or prior art description, obviously, the drawing in the following description is some embodiments of the utility model, for the ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other drawings according to these drawings.
[0020] Figure 1 It is the exploded structure schematic view of the electric core of prior art;
[0021] Figure 2 It is the structure schematic view of the electric core cover plate assembly of the utility model embodiment;
[0022] Figure 3 It is Figure 2 The structure schematic view of middle cover plate and boss;
[0023] Figure 4 It is Figure 2 The structure schematic view of bracket;
[0024] Figure 5 It is the structure schematic view of the electric core of the utility model embodiment;
[0025] Figure 6 It is Figure 5 The exploded structure schematic view of the electric core shown in;
[0026] Figure 7 It is Figure 5 The top view of the electric core shown in;
[0027] Figure 8 It is Figure 7 The section view along A-A in;
[0028] Figure 9 It is Figure 8 The enlarged view of the local structure in.
[0029] Mark explanation:
[0030] 1, cell cover plate assembly; 11, cover plate; 12, explosion-proof valve; 13, plastic part; 14, support structure; 141, boss; 142, bracket; 1421, support plate; 1422, support leg; 1423, exhaust through hole; 1424, exhaust gap; 143, plug-in protrusion; 144, plug-in hole; 15, exhaust passage; 2, shell; 3, pole group. DETAILED DESCRIPTION
[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.
[0032] At present, traditional cells, such as Figure 1 As shown, the cell includes a shell, both ends of the shell are open, two cell cover plate assemblies are arranged at the two open ends, and the cell cover plate assembly is integrated with a cover plate, a pole, an explosion-proof valve and a plastic part. The shell is provided with a pole group, and the plastic part is between the cover plate and the pole group, which plays a role in supporting and fixing the pole group.
[0033] In the length direction of the cell, the pole group is mainly insulated and fixed by the lower plastic in the cell cover plate assembly, but such insulation materials generally use pp material, and the strength and high temperature resistance are very limited, generally around 150 degrees Celsius, but the temperature of thermal runaway of the cell is usually much higher than the melting point of these insulation materials. When the cell is in thermal runaway, these fixed structures inside the cell have melted and failed. At this time, the pole group is left inside the cell, and due to the melting of the insulation protection material, the gap between the pole group and the cover plate and the shell is increased. At this time, the pole group has a high degree of freedom inside the cell. Due to the directional exhaust of high temperature and high pressure gas to the explosion-proof valve, the pole group will randomly move and block the explosion-proof valve on the cover plate, thereby blocking the exhaust passage, greatly reducing the exhaust effect of the explosion-proof valve and reducing the safety performance of the cell.
[0034] The embodiments of the utility model will be described below in combination with Figures 2 to 9
[0035] According to the embodiment of the utility model, first aspect, provide a kind of electric core cover plate assembly 1, including cover plate 11, explosion-proof valve 12, plastic piece 13 and at least one support structure 14.Cover plate 11 is equipped with assembly hole, cover plate 11 has the first surface towards the pole group 3 of electric core;Explosion-proof valve 12 is equipped in assembly hole;Plastic piece 13 is equipped in the first surface of cover plate 11;Support structure 14 is located between cover plate 11 and plastic piece 13 and along X direction is located in the arbitrary side of explosion-proof valve 12, the melting point of support structure 14 is higher than the melting point of plastic piece 13, support structure 14 is suitable for supporting between pole group 3 and cover plate 11 after plastic piece 13 is fused due to high temperature inside electric core, form the exhaust passage 15 communicated with explosion-proof valve 12, the height of exhaust passage 15 is H1, 3mm≤H1≤6mm.
[0036] The electric core cover plate assembly 1 provided by the utility model is provided with explosion-proof valve 12 protection structure, by setting the support structure 14 with the melting point greater than plastic piece 13, when high-temperature and high-pressure gas is generated inside the electric core, plastic piece 13 melts and fails, at this time, the support structure 14 has not been melted, and the pole group 3 will have a tendency to move towards the explosion-proof valve 12 under the action of the high-temperature and high-pressure gas, at this time, the support structure 14 can effectively support and fix the pole group 3, so that the pole group 3 does not randomly move and block the explosion-proof valve 12 on the cover plate 11 to affect the exhaust effect of the explosion-proof valve 12 when the electric core occurs thermal runaway, and the support structure 14 makes the pole group 3 and the cover plate 11 maintain the exhaust passage 15 communicated with the explosion-proof valve 12, ensures that the exhaust of the explosion-proof valve 12 is not affected, and improves the safety performance of the electric core.
[0037] Specifically, as shown in Figure 2 X direction, that is, the length direction of the cover plate 11. Z direction in the following, that is, the thickness direction of the cover plate 11. Along the X direction, the support structure 14 is located on the arbitrary side of the explosion-proof valve 12, which means that the support structure 14 is arranged on the arbitrary side or both sides of the explosion-proof valve 12.
[0038] In some embodiments, the support structure 14 includes a boss 141 arranged on the first surface of the cover plate 11 and a bracket 142 connected with the boss 141, and the height of the side of the bracket 142 away from the cover plate 11 protruding from the first surface of the cover plate 11 is the height of the exhaust passage 15.
[0039] The support structure 14 is in the form of a boss 141 and a bracket 142, which can facilitate the connection between the bracket 142 and the cover plate 11. Since the bracket 142 is connected to the boss 141, the bracket 142 and the boss 141 together constitute the protective structure of the explosion-proof valve 12. When the battery cell is in thermal runaway and the plastic part 13 melts and fails, the battery cell moves to the position of the explosion-proof valve 12 under the impact of high-temperature and high-pressure gas. The bracket 142 and the boss 141 are located between the cover plate 11 and the pole group 3, and play a supporting role. The height of the boss 141 protruding from the first surface of the cover plate 11 is the sum of the height of the bracket 142, which is the height of the exhaust passage 15 between the pole group 3 and the cover plate 11.
[0040] In some embodiments, the height H2 of the boss 141 protruding from the first surface of the cover plate 11 is 1.0mm≤H2≤2.0mm.
[0041] The height H2 of the boss 141 protruding from the first surface of the cover plate 11 is in the range of 1.0mm to 2.0mm. In this way, the boss 141 can constitute part of the support structure 14 in the Z direction, i.e. the height direction, while ensuring that the boss 141 is easy to process and easy to connect with the bracket 142, providing a stable connection seat for the bracket 142.
[0042] In some embodiments, the boss 141 is provided as a prism, which is easy to process.
[0043] In some embodiments, the bracket 142 includes a support plate 1421 and at least two legs 1422 provided at the edge of the support plate 1421. The number and position of the boss 141 correspond to the number and position of the legs 1422, and each leg 1422 is connected to one boss 141.
[0044] By providing the legs 1422 at the edge of the support plate 1421 and corresponding the boss 141 with the bracket 142, one leg 1422 is connected to one boss 141, which can stably connect the bracket 142 with the cover plate 11.
[0045] In this embodiment, two legs 1422 are provided at opposite edges of one support plate 1421, i.e. four legs 1422 are provided at one support plate 1421. Four bosses 141 are provided on the first surface of the cover plate 11, and the four bosses 141 are positionally matched with the four legs 1422. The legs 1422 and the bosses 141 are welded to realize the fixed connection between the bracket 142 and the cover plate 11.
[0046] In some embodiments, the support plate 1421 is stamped from an aluminum plate. The legs 1422 of the support plate 1421 are fixed to the surface of the boss 141 away from the cover plate 11 by welding, and the boss 141 and the bracket 142 are combined into the protective structure of the explosion-proof valve 12.
[0047] In some embodiments, two support structures 14 are provided, and the two support structures 14 are respectively provided on both sides of the explosion-proof valve 12 along the X direction.
[0048] In this embodiment, two support structures 14 are provided. Specifically, on the first surface of the cover plate 11, two sets of bosses 141 and two brackets 142 are provided. The position and number of bosses 141 in each set correspond to the position and number of legs 1422 of the brackets 142. The two brackets 142 are welded and fixed to the two sets of bosses 141 respectively.
[0049] By setting two support structures 14, the support effect of the support structures 14 on the electrode group 3 can be improved when thermal runaway occurs in the battery cell. Furthermore, since the two support structures 14 are respectively located on both sides of the explosion-proof valve 12, they can provide stable support for the electrode group 3 along the X direction, ensuring the stability of the support structure 14 on the electrode group 3 after the plastic part 13 melts and fails, maintaining the balance of the electrode group 3, and further ensuring the smoothness of the exhaust channel 15.
[0050] Furthermore, in some embodiments, two support structures 14 are symmetrically distributed on both sides of the explosion-proof valve 12.
[0051] In some embodiments, the minimum distance along the X direction between the boss 141 near the explosion-proof valve 12 and the explosion-proof valve 12 is L, where 5mm≤L≤8mm.
[0052] The boss 141 near the explosion-proof valve 12 is spaced apart from the explosion-proof valve 12, and the minimum distance between them is controlled within the range of 5mm to 8mm. This ensures that the support structure 14 can support the pole group 3 and maintain the exhaust channel 15 while keeping the exhaust channel 15 unobstructed, thus ensuring that the exhaust effect of the explosion-proof valve 12 is not affected.
[0053] In some embodiments, the support plate 1421 is provided with a plurality of exhaust holes 1423; and / or, the support leg 1422, the support plate 1421 and the cover plate 11 have an exhaust gap 1424 communicating with the exhaust channel 15.
[0054] By providing several exhaust holes 1423 on the support plate 1421, gas can flow through the exhaust holes 1423, improving the smooth flow of high-temperature and high-pressure gas in the exhaust channel 15.
[0055] Furthermore, by employing the support leg 1422, compared to the technical solution of a long strip flange formed outward from the support plate 1421, the support leg 1422 allows for an exhaust gap 1424 between the support plate 1421 and the cover plate 11, further improving the flow of gas within the exhaust channel 15. Simultaneously, it reduces the material used in the support leg 142, thereby reducing the overall weight of the cell cover assembly 1.
[0056] When thermal runaway occurs inside the cell, the bracket 142 first supports the electrode group 3, so that the exhaust channel 15 is maintained between the electrode group 3 and the explosion-proof valve 12. In addition, the exhaust hole 1423 on the support plate 1421, as well as the exhaust gap 1424 in the Z direction of the support leg 1422, bracket 142 and cover plate 11 are connected to the exhaust channel 15, which can ensure the exhaust requirements.
[0057] In some embodiments, one of the boss 141 and the support leg 1422 is provided with a plugging protrusion 143, and the other is provided with a plugging hole 144 that mates with the plugging protrusion 143. The boss 141 and the support leg 1422 are plugged in through the mating of the plugging protrusion 143 and the plugging hole 144, and are fixed by welding.
[0058] In this embodiment, the boss 141 is provided with a plug-in protrusion 143, and the support leg 1422 is provided with a plug-in hole 144. When the bracket 142 and the boss 141 are fixedly connected, the plug-in hole 144 of the support leg 1422 is plugged into the plug-in protrusion 143 of the boss 141, and then the boss 141 and the support leg 1422 are welded and fixed. This arrangement can further improve the welding effect and ensure the overall structural strength of the support structure 14.
[0059] The 144 socket can be a through hole or a blind hole, depending on the actual situation.
[0060] According to an embodiment of the present invention, in a second aspect, a battery cell is also provided, including a housing 2, an electrode group 3, and a battery cell cover assembly 1 as described in the above embodiments. The housing 2 has an open end; the electrode group 3 is disposed inside the housing 2; and the battery cell cover assembly 1 is disposed at the open end of the housing 2, encapsulating the electrode group 3 inside the housing 2.
[0061] Since the battery cell includes a battery cell cover assembly 1, which has the same effect as the battery cell cover assembly 1, it will not be described in detail here.
[0062] According to an embodiment of the present invention, in a third aspect, a battery pack is also provided, including the battery cells described in the above embodiments.
[0063] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.
[0064] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A cell cover assembly, characterized in that, include: A cover plate having mounting holes and a first surface facing the electrode assembly of the battery cell; An explosion-proof valve is disposed in the assembly hole; A plastic part, the plastic part being disposed on the first surface of the cover plate; At least one support structure is provided between the cover plate and the plastic part and located on any side of the explosion-proof valve along the X direction. The melting point of the support structure is higher than that of the plastic part. The support structure is adapted to support the electrode group and the cover plate after the plastic part melts due to the high temperature inside the battery cell, forming an exhaust channel communicating with the explosion-proof valve. The height of the exhaust channel is H1, 3mm≤H1≤6mm.
2. The cell cover assembly according to claim 1, characterized in that, The support structure includes a boss on the first surface of the cover plate and a bracket connected to the boss. The height of the side of the bracket away from the first surface of the cover plate that protrudes from the first surface of the cover plate is equal to the height of the exhaust channel.
3. The cell cover assembly according to claim 2, characterized in that, The height of the boss protruding from the first surface of the cover plate is H2, where 1.0mm ≤ H2 ≤ 2.0mm.
4. The cell cover assembly according to claim 3, characterized in that, The bracket includes a support plate and at least two legs located on the edge of the support plate. The number and position of the bosses correspond to the number and position of the legs, and each leg is connected to one of the bosses.
5. The cell cover assembly according to any one of claims 1 to 4, characterized in that, The support structure is provided in two parts, and the two support structures are respectively located on both sides of the explosion-proof valve along the X direction.
6. The cell cover assembly according to any one of claims 2 to 4, characterized in that, The minimum distance along the X direction between the boss near the explosion-proof valve and the explosion-proof valve is L, where 5mm ≤ L ≤ 8mm.
7. The cell cover assembly according to claim 4, characterized in that, The support plate is provided with several exhaust holes; And / or, there is an exhaust gap between the leg, the support plate and the cover plate that communicates with the exhaust channel.
8. The cell cover assembly according to claim 4, characterized in that, Of the boss and the support leg, one is provided with a plug-in protrusion, and the other is provided with a plug-in hole that mates with the plug-in protrusion. The boss and the support leg are plugged in through the mating of the plug-in protrusion and the plug-in hole, and then welded to be fixed.
9. A battery cell, characterized in that, include: A housing having an open end; A pole assembly, wherein the pole assembly is disposed within the housing; The cell cover assembly according to any one of claims 1 to 8, wherein the cell cover assembly is disposed at the open end of the housing and encapsulates the electrode assembly within the housing.
10. A battery pack, characterized in that, Includes the battery cell described in claim 9.