Patent Application
20240222770
This application claims the priority benefit of China application serial no. 202223593081.X, filed on Dec. 30, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to the technical field of batteries, in particular to an insulation structure and a secondary battery.
In the field of battery manufacturing for new energy, in order to reduce the metal shavings in the housing and avoid the risk of internal short circuit of lithium batteries, most current manufacturers replace tab die-cutting with full-tab type batteries.
When the conventional insulation material (such as Mylar sheet) is folded, there is a gap at the bottom. When the battery cell is a full-tab type battery cell, it is very likely to touch the bottom of the housing, and there is a risk of short-circuit insulation.
In order to overcome the short-circuit insulation risk which might occur at the gap of bottom, multi-layer insulation materials are normally adopted to cover the gap at the bottom. However, such multi-layer insulation materials will increase the overall thickness or length of the electrode assembly of the battery cell at the covered place and affect the assembly and use of the battery.
The technical problem to be solved by the disclosure is to provide an insulation structure and a secondary battery in order to overcome the defect of the related art, that is, the insulation wrapping of the electrode assembly is poor, and the thickness of the battery is increased when fully coated.
The disclosure solves the technical problems described above through the following technical solutions.
An insulation structure of the disclosure includes a first insulation member, the first insulation member includes a bottom surface covering area and a side covering area, and the side covering area is located on the same side of the bottom surface covering area to form an accommodation space.
The side covering area includes two opposite first side covering areas and two opposite second side covering areas.
At least one of the two opposite first side covering areas includes a central overlapping area, a first side overlapping area and a second side overlapping area. The central overlapping area is formed by extending the bottom surface covering area, and the first side overlapping area is formed by extending one of the two opposite first side covering areas, and the second side overlapping area is formed by extending the other of the two opposite first side covering areas.
Two of the central overlapping area, the first side overlapping area and the second side overlapping area do not overlap each other, and the other of the central overlapping area, the first side overlapping area and the second side overlapping area at least partially covers an area between the two areas that are not overlapped.
In the solution, by folding and covering the three overlapping areas (the central overlapping area, the first side overlapping area and the second side overlapping area), the insulation wrapping of the first side covering area on the three overlapping areas is realized. Two of the three overlapping areas do not overlap each other, and the other at least partially covers an area between the two areas that are not overlapped, so that the other overlapping area is able to cover the edge gap formed by the folded overlapping area of the two areas that are not overlapped, thus improving the insulation effect of the cladding on the three overlapping sides. In the meantime, the two areas that are not overlapped among the three overlapping areas make the first side covering area cover a layer of insulation structure, the other of the three overlapping areas allows the first side covering area to have a structure with at most two insulation layers. In this way, the thickness of the battery cell will not be increased, and the space utilization rate is improved.
Preferably, edges of two of the central overlapping area, the first side overlapping area and the second side overlapping area are joined to form a junction, and the other of the central overlapping area, the first side overlapping area and the second side overlapping area at least partially covers the junction.
In this solution, two of the three overlapping areas (the central overlapping area, the first side overlapping area and the second side overlapping area) are not overlapped by means of connecting edges, making the first insulation member to be easily cut so it is easy to control the precision of cutting. In this way, the gap at the edge formed after connection is as small as possible to improve the insulation effect of the edge of the junction. In the meantime, it is possible to ensure the two overlapping areas forming the junction do not increase the thickness of the first side covering area. The junction is at least partially covered by the other of the three overlapping areas, so that the connected gap at the edge is covered and the insulation effect of the connected gap at the edge is increased.
Preferably, the shape of the junction is one of straight line, curved line and stepped shape.
In this solution, the shape of the junction adopts one of straight line, curved line and stepped shape, which is easy to cut, and it is easy to control the edges of the two overlapping areas forming the junction to be consistent and reduce errors.
Preferably, one of the first side overlapping area and the second side overlapping area is connected to an edge of the central overlapping area to form the junction.
In the solution, one of the first side overlapping area and the second side overlapping area is adopted to be connected with the edge of the central overlapping area to form a junction, so that the junction only exists on one side of the central overlapping area, and only one side needs to be cut to form a junction and reduce the process. The other one of the first side overlapping area and the second side overlapping area is folded to cover the other side of the central overlapping area, which may ensure the insulation effect at the edge of the other side.
Preferably, edges of the first side overlapping area and the second side overlapping area are joined to form the junction.
In this solution, the edges of the first side overlapping area and the second side overlapping area are joined to form a junction, so that the central overlapping area does not need to be cut, and the folded edges of the central overlapping area and the bottom surface covering area are kept intact and insulated.
Preferably, a transition gap is provided at the junction of the central overlapping area, the bottom surface covering area and the second side covering area.
In this solution, a transition gap is provided at the junction of the central overlapping area, the bottom surface covering area and the second side covering area, so that the three overlapping areas (the central overlapping area, the first side overlapping area and the second side overlapping area) are easily folded at the transition gap. In this way, it is possible to avoid the occurrence of stress at the junction to make the first insulation member crack, thus avoiding the risk of electric leakage.
Preferably, the first insulation member is integrally formed.
In this solution, the first insulation member is integrally formed, which makes the first insulation member easy to process and avoids insulation risks caused by separation and splicing.
Preferably, the insulation structure further includes a second insulation member, and the second insulation member covers the gap at the edge of the junction.
In this solution, the gap at the edge of the junction is covered by the second insulation member, so that the gap at the edge generated by the non-overlapping junction is covered by the second insulation member, thereby ensuring the full insulation effect of each edge of the junction.
Preferably, the insulation structure further includes a fixing part, and the fixing part connects the other one of the central overlapping area, the first side overlapping area and the second side overlapping area and the two opposite second side covering areas.
In this solution, the other of the three overlapping areas (the central overlapping area, the first side overlapping area and the second side overlapping area) and the two opposite second side covering areas are connected by the fixing part, and the two opposite second side covering areas are fixed with other covering areas to form an accommodation space, which also makes the three overlapping areas (bottom surface covering area, first side covering area and second side covering area) have connection strength after folding to ensures the stability of accommodation space.
Preferably, the insulation structure further includes a third insulation member, the third insulation member covers at least part of the top area of the accommodation space and at least partially overlaps with the side covering area.
In this solution, the insulation effect of the top area is achieved through the third insulation member of the above structure, and the folding edge of the third insulation member folded toward the side covering area achieves the insulation effect, thereby improving the insulation effect of the entire insulation structure in various covering areas. By at least partially overlapping the third insulation member with the side covering area, it is also possible to avoid the situation that the third insulation member is too long to be flattened with the side covering area.
Preferably, the third insulation member covers an area corresponding to the explosion-proof valve.
In this solution, the area corresponding to the explosion-proof valve is covered by the third insulation member, so that the area of the explosion-proof valve is insulated to ensure safety.
Preferably, the material of the third insulation member includes colloid.
In this solution, the material of the third insulation member includes colloid, so that the third insulation member is viscous and is able to be connected to the side covering area, thereby obtaining a better fixing effect.
Preferably, the accommodation space is adopted to cover the electrode assembly.
In this solution, the accommodation space is adopted to cover the electrode assembly, so that various covering surfaces and the junction edge of the electrode assembly are insulated and protected to avoid the risk of electric leakage.
A secondary battery of the disclosure includes an electrode assembly, a housing, a top cover assembly and the above-mentioned insulation structure.
The housing has an opening, the electrode assembly is accommodated in the housing, and the top cover assembly is connected to the housing and covers the opening of the housing. The insulation structure covers the outer side of the electrode assembly.
In this solution, the above-mentioned insulation structure is adopted to cover the outer side of the electrode assembly to separate the housing from the electrode assembly, thereby improving the insulation effect between the covered surface and edge of the electrode assembly and the housing, and avoiding the risk of short circuit. Also, the thickness of the electrode assembly on the first side covering area is not increased, and the subsequent configuration requirements of the secondary battery are not affected.
A battery pack of the disclosure includes:
a box;
a secondary battery as described above;
a cover covers the opening of the box to form a closed space with the space of the box to accommodate the secondary battery.
The positive advantageous effect of the disclosure is that the insulation structure and the secondary battery realize insulation wrapping of the first side covering area on the three overlapping areas by folding and covering the three overlapping areas (the central overlapping area, the first side overlapping area and the second side overlapping area). Two of the three overlapping areas do not overlap each other, and the other at least covers an area between the two areas that are not overlapped with each other, which enables another overlapping area to cover the edge gap formed by two non-overlapping overlapping areas during non-overlapping folding, thereby improving the insulation effect of the cladding on the three overlapping areas. In the meantime, the two areas that are not overlapped among the three overlapping areas make the first side covering area cover a layer of insulation structure, the other of the three overlapping areas allows the first side covering area to have a structure with at most two insulation layers. In this way, the thickness of the battery cell will not be increased, and the space utilization rate is improved.
A preferred embodiment is given below, and the disclosure is described more clearly and completely in conjunction with the accompanying drawings.
As shown in
The first insulation member 1 includes a bottom surface covering area 2 and a side covering area 3, and the side covering area 3 is located on the same side of the bottom surface covering area 2 to form an accommodation space 4.
The side covering area includes two opposite first side covering areas 31 and two opposite second side covering areas 32.
The two opposite first side covering areas 31 include a central overlapping area 310, a first side overlapping area 320 and a second side overlapping area 330. The central overlapping area 310 is formed by extending the bottom surface covering area 2, the first side overlapping area 320 is formed by extending one of the two opposite first side covering areas 31, and the second side overlapping area 330 is formed by extending the other of the two opposite first side covering areas 31.
Two of the central overlapping area 310, the first side overlapping area 320 and the second side overlapping area 330 do not overlap each other, and the other one of the central overlapping area 310, the first side overlapping area 320 and the second side overlapping area 330 covers an area between the two areas that are not overlapped.
In the insulation structure 100, by extending and forming three overlapping areas (the central overlapping area 310, the first side overlapping area 320 and the second side overlapping area 330), the insulation wrapping of the first side covering area 31 on the three overlapping areas is realized. Two of the three overlapping areas do not overlap each other, and the other covers an area between the two areas that are not overlapped, so that the other overlapping area is able to cover the edge gap formed by the folded overlapping area of the two areas that are not overlapped, thus improving the insulation effect of the cladding on the three overlapping areas. In the meantime, the two areas that are not overlapped make the first side covering area 31 cover a layer of insulation structure, the other of the three overlapping areas allows the first side covering area 31 to have a structure with at most two insulation layers. In this way, the thickness of the battery cell will not be increased, and the space utilization rate is improved. In this way, it is possible to realize that the thickness of the battery on the overlapped and covered area is not increased, so as to ensure the subsequent dimensional requirements of the battery assembly.
The accommodation space 4 is configured to cover the electrode assembly 21. That is to say, the insulation structure 100 covers the electrode assembly 21 in such accommodation space 4, so that each covering surface and junction edge of the electrode assembly 21 are isolated from the outer housing, thereby providing insulation protection and avoiding the risk of short circuit.
In other embodiments, not all surfaces may need to be insulated, and only one first side covering area 31 may have three overlapping areas, instead of both first side covering areas 31 having three overlapping areas. Therefore, the positions of the three overlapping areas may be adjusted correspondingly according to the needs of the insulation wrapping. Moreover, according to the needs of the object to be insulated, three overlapping areas may also be cut in the second side covering area 32.
Specifically, as shown in
In such an embodiment, two of the three overlapping areas are not overlapped by means of edge bonding, so that the first insulation member 1 is easy to cut, and the precision of cutting is easy to control. In this way, the gap at the edge formed after connection is as small as possible to improve the insulation effect of the edge of the junction 6. Moreover, the junction 6 only exists on one side of the central overlapping area 310 (that is, the side near the first side overlapping area 320), and only one side needs to be cut to form the junction 6, thus reducing the operation steps. After the second side overlapping area 330 is folded, the second side overlapping area 330 covers the other side of the central overlapping area 310 (that is, the side close to the second side overlapping area 330), which may ensure the insulation effect on the edge of the other side. In the meantime, it is also ensured that the two overlapping areas forming the junction 6 do not increase the thickness of the first side covering area 31.
The junction 6 is covered by the other one of the three overlapping areas, so that the connected edge gap is covered and the insulation effect of the connected edge gap is improved.
In other embodiments, which two of the three overlapping areas are selected to be bonded to form the junction 6 and the remaining one covers the junction 6 may be freely combined and adjusted according to actual needs. For example, it is also possible to cut out two gaps 5 with matching sizes and shapes in the first side overlapping area 320 and the second side overlapping area 330 respectively. In this way, after the first side overlapping area 320 and the second side overlapping area 330 are folded over, their edges are joined to form the junction 6. The junction 6 is formed by joining the edges of the first side overlapping area 320 and the second side overlapping area 330, so that the central overlapping area 310 does not need to be cut, and the folded edges of the central overlapping area 310 and the bottom surface covering area 2 are kept intact and insulated.
Moreover, in addition to achieving non-overlapping by means of edge joints, in other embodiments, due to the differences between insulation materials or the differences between the shapes and structures of insulated objects, other structures that may achieve non-overlapping may also be adopted. The degree of coverage of the edge gap between the non-overlapping areas by another of the three overlapping areas will be different because of the shape and size of the gap formed by the non-overlapping areas. In this example, the junction 6 is covered by the second side overlapping area 330, closing the connected edge gap is a preferred implementation method, which may cover the edge gap to the greatest extent and improve the insulation effect.
As shown in
In other embodiments, the shape of the junction 6 may be adjusted accordingly according to the needs of the joint effect. Preferably, the shape of the junction 6 may be one of straight lines, curves and steps, which is easy to cut, and it is easy to control the edges of the two overlapping areas forming the junction 6 to be consistent, thereby reducing errors.
As shown in
As shown in
As shown in
In other embodiments, due to the different shapes of the junction 6 or the use of other non-overlapping structures, or the extension length of the second side overlapping area 330 is able to cross the junction edge between the central overlapping area 310 and the second side covering area 32 to close the small section of non-closed gap, the second insulation member 9 might be non-necessary.
As shown in
As shown in
This embodiment provides another insulation structure 100, the insulation structure 100 of this embodiment is substantially the same as the insulation structure 100 of Embodiment 1, the difference lies in:
The insulation structure 100 further includes a third insulation part, which is a part of the whole Mylar sheet, and a surface thereof is covered with colloid to make it sticky. The third insulation member at least covers part of the top area of the accommodation space 4 and partially overlaps with the side covering area 3. That is to say, in this implementation, the third insulation member does not completely cover the top area, and after the third insulation member is folded, the area covered by the side covering area 3 is only a small part, not all of them. In this way, it is possible to avoid that the third insulation member is too long to be leveled with the side covering area 3. In this embodiment, the length of the third insulation member is relatively short, so the third insulation member may be flattened with the side covering area 3 to obtain a better fixing effect. It should be understood that in other embodiments, the third insulation member may also cover the entire top area. In this embodiment, the insulation effect of the top area is achieved through the third insulation member with the above structure, and the folded edge of the third insulation member folded toward the side covering area may also achieve the insulation effect, thus improving the insulation effect of the entire insulation structure 100 in each covering area.
In this embodiment, the third insulation member at least exists in the middle section of the top, that is, the area below the explosion-proof valve, so that the area corresponding to the explosion-proof valve is insulated, avoiding leakage of the electrolyte, and further improving safety.
In other embodiments, depending on the different configuration areas of the explosion-proof valve, the position of the third insulation member will be adjusted accordingly.
As shown in
The housing has an opening (not shown in the figure), the electrode assembly 21 is accommodated in the housing. The top cover assembly 22 is connected to the housing and covers the opening of the housing. The central area of the top cover assembly 22 is provided with an explosion-proof valve 23, and the insulation structure 100 covers the outer side of the electrode assembly 21, that is, an insulation film is provided between the housing and the electrode assembly 21 to space the housing and the electrode assembly apart, thereby improving the insulation effect between the coated surface and edge of the electrode assembly and the housing, thus avoiding risk of short circuit. In the meantime, the thickness of the electrode assembly in the first side covering area 31 is not increased, and the subsequent configuration requirements of the secondary battery are not affected.
The present embodiment also provides a battery pack, the battery pack includes: a box, the secondary battery as described in Embodiment 3, and a cover; the cover is used to cover the opening of the box to form a closed space with the space of the box to accommodate the secondary battery.
Although the specific implementation of the disclosure has been described above, those skilled in the art should understand that this is only an example, and the protection scope of the disclosure is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202223593081.X | Dec 2022 | CN | national |
