Power battery structure and assembly method

Abstract

This application discloses a power battery structure and its assembly method. The power battery structure includes a core, a current collector, and an insulating pad. The current collector includes a welding plate portion protruding from the upper side of the current collector body, and a position of the welding plate portion is connected to the current collector body via a fusible portion. The insulating pad has a first through groove and a second through groove. When the insulating pad is assembled onto the current collector body, the welding plate portion slides upward through the first through groove and then relative to the upper side of the second through groove. The two sides of the welding plate portion are supported by the insulating pad on both sides of the second through groove, and the two ends of the fusible portion are stopped by the two opposite side walls of the second through groove. In the event of abnormally high temperature in the power battery, the fusible portion can be burned out to avoid safety risks to the battery. When the power battery abnormally burns out the fusible portion, the safety risks caused by secondary connection after the fusible portion burns out can be prevented by the supporting and limiting effect of the insulating pad.

Description

[0001] Power battery structure and assembly method Technical Field

[0002] This application relates to the field of battery technology, and in particular to a power battery structure and its assembly method. Background Technology

[0003] Currently, lithium-ion / sodium-ion power batteries (such as cylindrical power batteries) are gradually becoming the mainstream products in the new energy industry due to their advantages such as high energy density, good capacity consistency, and ability to support high-rate charging and discharging. More and more manufacturers are opting for aluminum-cased cylindrical power batteries combined with bottom-through welding technology to achieve battery lightweighting, increase vehicle range, and simultaneously meet consumers' daily needs for rapid travel (high-rate charging and discharging). Frequently Asked Questions:

[0004] The power battery uses a through-welding process for the bottom of the casing (and the current collector), resulting in a large contact area between the current collector and the bottom of the casing. This makes it difficult to implement a fuse design, which may pose a safety risk to the power battery.

[0005] In addition, if the power battery has a fuse structure directly installed in the current collector, even if the power battery burns out when there is an abnormality, vibration can easily trigger a second electrical connection (that is, the location where the fuse structure burns out will be electrically connected again), causing the battery fuse structure to fail and bringing new safety risks. Summary of the Invention

[0006] The purpose of this application is to provide a power battery structure and a method for assembling the power battery structure, which can solve at least one of the technical problems in the background art.

[0007] To achieve the above objectives, this application provides a power battery structure, comprising:

[0008] A collector plate, comprising a collector plate body and a welding plate portion protruding from the upper side of the collector plate body, wherein the collector plate body is welded to the full-pole tab at one end of the core, and a position of the welding plate portion is connected to the collector plate body through a fusion portion;

[0009] An insulating gasket has a first through groove and a second through groove that extend vertically through the upper and lower parts of the insulating gasket. The first through groove and the second through groove are connected. When the insulating gasket is assembled onto the main body of the manifold, the welding plate portion slides upward through the first through groove and then relative to the upper side of the second through groove. The two sides of the welding plate portion are supported by the insulating gasket on both sides of the second through groove. The two ends of the fused portion are stopped by the two opposite side walls of the second through groove.

[0010] In this embodiment, the current collector includes a current collector body and a welding plate protruding from the upper side of the current collector body. The welding plate and the current collector body are connected by a fusible link. An insulating gasket is provided on the current collector body to separate it from the welding plate. When the power battery experiences abnormally high temperatures, the fusible link can be burned out to avoid safety risks to the battery. Moreover, since the insulating gasket separates the current collector body and the welding plate from top to bottom, when the power battery abnormally burns out the fusible link, the insulating gasket's support and limiting effect can prevent the safety risks caused by secondary connection after the fusible link burns out. In addition, in this embodiment, the first and second through slots on the insulating gasket allow the insulating gasket that separates the current collector body and the welding plate from top to bottom to be smoothly assembled onto the current collector.

[0011] Optionally, the fusion break is connected to the outer edge of the welding plate, and a gap groove is formed between the outer edge of the welding plate and the main body of the manifold, with both ends of the gap groove terminating at the fusion break.

[0012] Optionally, the welding plate portion and the fusion cut portion are formed by stamping and cutting the manifold.

[0013] Optionally, the welding plate portion is circular, the first through groove is a circle with one end open to connect to the second through groove, and the radius of the first through groove is larger than the radius of the welding plate portion.

[0014] Optionally, the two opposite sidewalls of the second through groove gradually move closer together in a direction away from the first through groove.

[0015] Optionally, the welding plate portion is provided at the center of the coil core.

[0016] Optionally, a liquid injection through hole is formed on the welding plate portion, and the liquid injection through hole faces the second through groove.

[0017] Optionally, the power battery structure is a cylindrical power battery structure; the power battery structure further includes a housing, in which the winding core, the current collector and the insulating gasket are fitted; the outer edge of the insulating gasket is adapted to the side wall of the housing to be radially limited.

[0018] To achieve the above objectives, this application also provides a method for assembling a power battery structure, comprising the following steps:

[0019] The main body of the current collector is welded to the full-pole tab of the winding core;

[0020] Align the first through groove of the insulating pad with the welding plate portion, and then place the insulating pad on the main body of the current collector, with the welding plate portion moving upward through the first through groove;

[0021] Slide the insulating pad so that the welding plate portion slides relative to the upper side of the second through groove and the fused portion slides to the second through groove until both ends of the fused portion are stopped by the two opposite side walls of the second through groove, and both sides of the welding plate portion are supported by the insulating pad on both sides of the second through groove.

[0022] The above assembly method allows the insulating gasket that separates the manifold body and the welding plate to be smoothly assembled onto the manifold body to support and limit the welding plate. It also helps to ensure the structural strength of the insulating gasket, thereby ensuring the functional effect of the insulating gasket.

[0023] To achieve the above objectives, this application also provides a method for assembling a power battery structure, comprising the following steps:

[0024] The main body of the current collector is welded to the full-pole tab of the winding core;

[0025] Align the first through groove of the insulating pad with the welding plate portion, and then place the insulating pad on the main body of the current collector, with the welding plate portion moving upward through the first through groove;

[0026] Slide the insulating pad so that the welding plate portion slides relative to the upper side of the second through groove and the fused portion slides to the second through groove until both ends of the fused portion are stopped by the two opposite side walls of the second through groove, and both sides of the welding plate portion are supported by the insulating pad on both sides of the second through groove.

[0027] The core, the current collector, and the insulating pad are fitted into the housing, and the sidewall of the housing radially limits the insulating pad.

[0028] The above assembly method allows the insulating gasket, which separates the manifold body and the welding plate, to be smoothly assembled onto the manifold body to support and limit the welding plate. This also helps ensure the structural strength of the insulating gasket, thereby guaranteeing its functional performance. Furthermore, because the sidewalls of the housing radially limit the insulating gasket, and the fused portion is stopped and limited by the two opposite sidewalls of the second through slot, the circumferential limiting effect of the fused portion achieves circumferential limiting of the insulating gasket. Attached Figure Description

[0029] Figure 1 This is a cross-sectional structural diagram of the power battery structure according to an embodiment of this application.

[0030] Figure 2 This is a cross-sectional view of the power battery structure in an embodiment of this application, omitting the casing.

[0031] Figure 3 This is a three-dimensional structural diagram of the core and collector plate in the embodiments of this application.

[0032] Figure 4 This is a three-dimensional structural diagram of the current collector and insulating pad in an embodiment of this application.

[0033] Figure 5 This is an exploded structural diagram of the current collector and insulating pad in an embodiment of this application.

[0034] Figure 6 This is a top view of the collector structure in an embodiment of this application.

[0035] Figure 7 This is a cross-sectional structural diagram of the collector disk in an embodiment of this application. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] Please see Figures 1 to 7 This application discloses a power battery structure, including a core 10, a current collector 20, and an insulating pad 30. The current collector 20 includes a current collector body 21 and a welding plate portion 22 protruding from the upper side of the current collector body 21. The current collector body 21 is welded to a tab at one end of the core 10. A position of the welding plate portion 22 is connected to the current collector body 21 through a fusible part 23. The insulating pad 30 has a first through groove 31 and a second through groove 32 that pass through vertically. The first through groove 31 and the second through groove 32 are connected. When the insulating pad 30 is assembled onto the current collector body 21, the welding plate portion 22 slides upward through the first through groove 31 and then relative to the upper side of the second through groove 32. The two sides of the welding plate portion 22 are supported on the two sides of the insulating pad 30 at the second through groove 32. The two ends of the fusible part 23 are stopped by the two opposite side walls of the second through groove 32.

[0038] It should be explained that the fact that the two sides of the solder plate portion 22 are supported by the insulating pads 30 on both sides of the second through groove 32 does not mean that the solder plate portion 22 is only supported by the insulating pads 30 on both sides of the second through groove 32. In the example in the attached figure, the insulating pads 30 on the outer area of ​​the second through groove 32 form a C-shaped support for the solder plate portion 22.

[0039] In this embodiment, the current collector 20 includes a current collector body 21 and a welding plate portion 22 protruding from the upper side of the current collector body 21. The welding plate portion 22 and the current collector body 21 are connected by a fusible portion 23. An insulating gasket 30 is provided on the current collector body 21 to separate it from the welding plate portion 22. When the power battery experiences abnormally high temperatures, the fusible portion 23 can be burned out to avoid safety risks to the battery. Moreover, since the insulating gasket 30 separates the current collector body 21 and the welding plate portion 22 vertically, when the power battery abnormally burns out the fusible portion 23, the insulating gasket 30 can support and limit the connection after the fusible portion 23 burns out, preventing the safety risks caused by secondary connection after the fusible portion 23 burns out. In addition, in this embodiment, the first through groove 31 and the second through groove 32 on the insulating gasket 30 allow the insulating gasket 30, which separates the current collector body 21 and the welding plate portion 22 vertically, to be smoothly assembled into the current collector 20.

[0040] In some embodiments, the power battery structure is a cylindrical power battery structure, but it is not limited to this.

[0041] In some embodiments, the power battery structure further includes a housing 40 sleeved on the outside of the core 10. The welding plate portion 22 is welded to the inner side of the bottom 41 of the housing 40. Due to the support of the insulating gasket 30 for the welding plate portion 22, when penetration welding with the bottom 41 is required, it can be ensured that the welding plate portion 22 fits well with the bottom 41 to facilitate penetration welding, without the need to use a clamp to support the welding plate portion 22, which is beneficial to improving production efficiency.

[0042] Of course, the welding plate 22 is not limited to being welded to the bottom of the shell 41. For example, it can also be welded to the cover that fits over the end of the shell 40 or to the pole.

[0043] In some embodiments, the manifold 20 is made entirely of aluminum. However, this is not a limitation.

[0044] In some embodiments, the insulating pad 30 may be made of PP or PET. However, it is not limited to this.

[0045] In some embodiments, the gap H between the welding plate portion 22 and the collector plate body 21 is equal to the thickness of the insulating gasket 30, so that after the insulating gasket 30 is assembled, it can fit and support the welding plate portion 22.

[0046] In some embodiments, the fusible link 23 is connected to the outer edge of the welding plate portion 22, and a gap groove is formed between the outer edge of the welding plate portion 22 and the manifold body 21, with both ends of the gap groove terminating at the fusible link 23. Specifically, the length of the fusible link 23 is much smaller than the length of the gap groove. When the welding plate portion 22 is circular, the included angle α defined by the fusible link 23 can be set to less than 60 degrees, and correspondingly, the included angle defined by the gap groove is greater than 300 degrees.

[0047] It should be noted that the fusing portion 23 located on the outer edge of the solder plate portion 22 may include at least two sub-fusing portions, where the two ends of the fusing portion 23 refer to the outer sides of the two outermost sub-fusing portions 23.

[0048] Specifically, the welding plate portion 22 and the fusing portion 23 are formed by stamping and cutting the manifold 20. The welding plate portion 22, the fusing portion 23, and the manifold body 21 are single-piece structures, that is, formed by processing a single sheet of material. The manifold 20 can be cut before stamping, and then stamped upwards to directly form the welding plate portion 22, the fusing portion 23, and the spacer groove. Of course, it is also possible to stamp first and then cut out the fusing portion 23 and the spacer groove.

[0049] Furthermore, the fusible portion 23 and the welding plate portion 22 are not limited to being formed by stamping or cutting. For example, the fusible portion 23 can also be welded to the manifold body 21.

[0050] In some embodiments, the solder plate portion 22 is circular. However, this is not a limitation.

[0051] Specifically, the first through groove 31 is circular with one end open, and connects to the second through groove 32 through the open end. The radius of the first through groove 31 is larger than the radius of the solder plate portion 22. Because the radius of the first through groove 31 is larger than the radius of the solder plate portion 22, the solder plate portion 22 can smoothly pass upward through the first through groove 31 when assembling the insulating gasket 30. Of course, the first through groove 31 is not limited to being circular.

[0052] Specifically, the distance between the two opposite sidewalls of the second through groove 32, that is, the width of the second through groove 32, is generally smaller than the diameter of the welding plate portion 22, so that the welding plate portion 22 can be supported by the insulating pads 30 portions on both sides of the second through groove 32.

[0053] In some embodiments, the two opposite sidewalls of the second through groove 32 gradually move closer together in a direction away from the first through groove 31. Of course, this is not a limitation, as long as the two sides of the welding plate portion 22 can be supported on the insulating gasket 30 on both sides of the second through groove 32 when the insulating gasket 30 is assembled in place, and the two ends of the fused portion 23 are stopped by the two opposite sidewalls of the second through groove 32.

[0054] In some embodiments, the welding plate portion 22 is provided at the center of the core 10. However, it is not limited to this.

[0055] Specifically, the core 10 has a core center hole 11, and the middle part of the welding plate portion 22 corresponds to the core center hole 11.

[0056] More specifically, a liquid injection through hole 221 corresponding to the center hole of the core 10 is formed in the middle of the welding plate portion 22, and the liquid injection through hole 221 faces the second through groove 32.

[0057] In some embodiments, a liquid injection through hole 221 is formed in the middle of the welding plate portion 22, and the liquid injection through hole 221 faces the second through groove 32.

[0058] In some embodiments, the power battery structure is a cylindrical power battery structure; the power battery structure also includes a housing 40, with the core 10, current collector 20, and insulating gasket 30 fitted inside the housing 40; the outer edge of the insulating gasket 30 is adapted to the side wall of the housing 40 for radial limiting. Since the side wall of the housing 40 radially limits the insulating gasket 30 after it is fitted inside the housing 40, and the fusible part 23 is stopped and limited on the two opposite side walls of the second through groove 32, the circumferential limiting of the insulating gasket 30 can be achieved by the limiting effect of the fusible part 23, thereby achieving reliable assembly of the insulating gasket 30.

[0059] Specifically, the insulating gasket 30 is disc-shaped, and its overall annular outer edge fits the side wall of the housing 40, which can better isolate the current collector body 21 and the bottom of the housing 41. Of course, the insulating gasket 30 is not limited to being disc-shaped.

[0060] In some embodiments, a recessed region 211 is formed on the collector plate body 21 and is welded to the full-pole tab of the core 10 through the recessed region 211. Specifically, the collector plate body 21 is generally disc-shaped, and the recessed region 211 includes at least two regions distributed circumferentially along the collector plate body 21.

[0061] In some embodiments, both the manifold body 21 and the insulating pad 30 are disc-shaped, and the diameter of the insulating pad 30 may be equal to or slightly larger than the diameter of the manifold body 21.

[0062] To better understand this application, the assembly process of the power battery structure is described below with reference to specific examples in the accompanying drawings. This should not be construed as limiting the scope of this application.

[0063] First, flatten / pat the full-pole tab at one end of the core 10.

[0064] Next, the collector plate body 21 is attached to the full tab of the core 10, and the liquid injection through hole 221 on the welding plate part 22 is aligned with the center hole 11 of the core. Then, the collector plate body 21 is welded to the full tab of the core 10 by laser welding.

[0065] Next, align the first through groove 31 of the insulating pad 30 with the solder plate portion 22, and then place the insulating pad 30 on the collector plate body 21, with the solder plate portion 22 moving upward through the first through groove 31.

[0066] Next, the insulating pad 30 is slid, so that the welding plate 22 slides relative to the upper side of the second through groove 32 and the fusion cut 23 slides to the second through groove 32 until the two ends of the fusion cut 23 are stopped by the two opposite side walls of the second through groove 32. At this time, the welding plate 22 is supported on the insulating pad 30, the insulating pad 30 is installed in place, and the outer edge of the insulating pad 30 is basically aligned with the outer wall of the core 10.

[0067] Next, the core 10, the collector plate 20, and the insulating gasket 30 are fitted into the housing 40. The sidewalls of the housing 40 radially limit the insulating gasket 30, and the welding plate portion 22 is attached to the inner side of the housing bottom 41. Because the sidewalls of the housing 40 radially limit the insulating gasket 30, and the fusible portion 23 is stopped and limited by the two opposite sidewalls of the second through groove 32, the circumferential limitation of the insulating gasket 30 can be achieved by the limiting effect of the fusible portion 23. Due to the support of the insulating gasket 30 for the welding plate portion 22, reliable adhesion between the welding plate portion 22 and the housing bottom 41 can be ensured.

[0068] Next, the welding plate 22 and the shell bottom 41 are welded together by laser penetration welding.

[0069] This application also discloses an assembly method for the aforementioned power battery structure, including the following steps:

[0070] The main body 21 of the collector plate is welded to the full-pole tab of the core 10;

[0071] Align the first through groove 31 of the insulating pad 30 with the welding plate portion 22, and then place the insulating pad 30 on the collector plate body 21, with the welding plate portion 22 moving upward through the first through groove 31;

[0072] The insulating pad 30 is slidable so that the welding plate portion 22 slides relative to the upper side of the second through groove 32 and the fusion portion 23 slides to the second through groove 32 until both ends of the fusion portion 23 are stopped by the two opposite side walls of the second through groove 32, and both sides of the welding plate portion 22 are supported by the insulating pad 30 on both sides of the second through groove 32.

[0073] By means of the above assembly method, the insulating pad 30 that separates the collector plate body 21 and the welding plate part 22 can be smoothly assembled on the collector plate body 21 to support and limit the welding plate part 22, and it is also beneficial to ensure the structural strength of the insulating pad 30, thereby ensuring the functional effect of the insulating pad 30.

[0074] Based on a specific example, after assembling the insulating pad 30, the above assembly method further includes:

[0075] The core 10, the collector plate 20, and the insulating pad 30 are fitted into the housing 40, and the side wall of the housing 40 radially limits the insulating pad 30.

[0076] Since the side wall of the housing 40 radially limits the insulating gasket 30, and the fusible part 23 is stopped and limited by the two opposite side walls of the second through groove 32, the circumferential limitation of the insulating gasket 30 can be achieved by the limiting effect of the fusible part 23.

[0077] The above-disclosed examples are merely preferred embodiments of this application, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the scope of this application are still within the scope of this application.

Claims

1. A power battery structure, characterized in that, include: Core; A collector plate, comprising a collector plate body and a welding plate portion protruding from the upper side of the collector plate body, wherein the collector plate body is welded to the full-pole tab at one end of the core, and the welding plate portion is connected to the collector plate body through a fusion section; An insulating gasket has a first through groove and a second through groove that extend vertically through the upper and lower parts of the insulating gasket. The first through groove and the second through groove are connected. When the insulating gasket is assembled onto the main body of the manifold, the welding plate slides upward through the first through groove and then relative to the upper side of the second through groove. The insulating gasket forms a C-shaped support for the welding plate in the outer area of ​​the second through groove. The two ends of the fused part are stopped by the two opposite side walls of the second through groove. The fusion break is connected to the outer edge of the welding plate, and a gap groove is formed between the outer edge of the welding plate and the main body of the collector plate. The two ends of the gap groove terminate at the fusion break.

2. The power battery structure according to claim 1, characterized in that, The welding plate portion and the fusion section are formed by stamping and cutting the manifold.

3. The power battery structure according to claim 1, characterized in that, The welding plate portion is circular, and the first through groove is a circle with one end open to connect to the second through groove. The radius of the first through groove is larger than the radius of the welding plate portion.

4. The power battery structure according to claim 1 or 3, characterized in that, The two opposite sidewalls of the second through groove gradually move closer together in a direction away from the first through groove.

5. The power battery structure according to claim 1, characterized in that, The welding plate is positioned at the center of the core.

6. The power battery structure according to claim 1, characterized in that, A liquid injection through hole is formed on the welding plate portion, and the liquid injection through hole faces the second through groove.

7. The power battery structure according to claim 1, characterized in that, The power battery structure is a cylindrical power battery structure; the power battery structure also includes a housing, and the core, the current collector and the insulating gasket are sleeved inside the housing; the outer edge of the insulating gasket is adapted to the side wall of the housing to be radially limited.

8. The assembly method of the power battery structure according to claim 1, characterized in that, Includes the following steps: The main body of the current collector is welded to the full-pole tab of the winding core; Align the first through groove of the insulating pad with the welding plate portion, and then place the insulating pad on the main body of the current collector, with the welding plate portion moving upward through the first through groove; Slide the insulating pad so that the welding plate portion slides relative to the upper side of the second through groove and the fused portion slides to the second through groove until both ends of the fused portion are stopped by the two opposite side walls of the second through groove, and both sides of the welding plate portion are supported by the insulating pad on both sides of the second through groove.

9. The assembly method of the power battery structure according to claim 7, characterized in that, Includes the following steps: The main body of the current collector is welded to the full-pole tab of the winding core; Align the first through groove of the insulating pad with the welding plate portion, and then place the insulating pad on the main body of the current collector, with the welding plate portion moving upward through the first through groove; Slide the insulating pad so that the welding plate portion slides relative to the upper side of the second through groove and the fused portion slides to the second through groove until both ends of the fused portion are stopped by the two opposite side walls of the second through groove, and both sides of the welding plate portion are supported by the insulating pad on both sides of the second through groove. The core, the current collector, and the insulating pad are fitted into the housing, and the sidewall of the housing radially limits the insulating pad.

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