Explosion-proof valve, battery cell assembly and battery
By setting buffer grooves and marking grooves on the valve body of the explosion-proof valve, the problem of thinner battery cells causing markings to be prone to fatigue and cracking is solved, and higher reliability and pressure relief rate are achieved.
Patent Information
- Application Number
- CN202421053457.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-13
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-05-13
AI Technical Summary
Thinner battery cells lead to thinner residual thickness of explosion-proof valve marks, and the marks are prone to fatigue and cracking under stress, and the failure problem is more serious.
An explosion-proof valve is designed, with buffer grooves and marking grooves on the valve body. The buffer groove absorbs vibration energy and reduces the stress of the marking groove. The marking groove is located on the bottom wall of the buffer groove to ensure maximum opening area and leakage. The pressure rate is increased.
It effectively reduces the stress of the marking groove, prevents fatigue cracking, ensures the reliability of the explosion-proof valve, improves the pressure relief rate, and reduces the risk of explosion of the battery cell.
Smart Images
Figure CN222463313U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of battery accessories, in particular to an explosion-proof valve, a battery core assembly and a battery. Background Art
[0002] The battery cell explosion-proof valve is a safety protection device for lithium batteries and other types of battery cells. The battery cell explosion-proof valve can release internal pressure by setting notches. When the internal pressure of the battery is too high, the notches of the explosion-proof valve make it easier to open the valve, thereby releasing the internal gas, reducing the internal pressure, and preventing the battery body from exploding due to excessive pressurization.
[0003] As the fast charging speed of power battery cells continues to increase, the voltage of the entire battery pack continues to increase, so each battery pack needs to install more cells, resulting in a thinner thickness of a single cell. Thinner cells reduce the area where the explosion-proof valve can be installed. When the opening pressure remains unchanged, the residual thickness of the notch will be very thin, and the ability to resist stress will decrease. In the production of cells, pack assembly and vehicle vibration conditions, the explosion-proof valve notch is subjected to stress, resulting in fatigue cracking failure, which is a more serious problem. Utility Model Content
[0004] In view of this, the utility model provides an explosion-proof valve, a battery core assembly and a battery to solve the problem that the residual thickness of the notch on the explosion-proof valve is relatively thin and the notch is prone to fatigue cracking under stress.
[0005] In a first aspect, the utility model provides an explosion-proof valve, comprising:
[0006] a valve body having an inner side and an outer side;
[0007] A buffer groove is provided on the valve body and is recessed toward the inner side of the valve body to form an annular groove structure;
[0008] The notched groove is arranged on the bottom wall of the buffer groove along the extending direction of the buffer groove.
[0009] Beneficial effects: The buffer groove formed on the valve body can absorb vibration energy, effectively reduce the stress on the notched groove under the conditions of battery cell production, pack assembly and vehicle vibration, and the notched groove is not easy to fail due to fatigue cracking, ensuring the reliability of the explosion-proof valve. The notched groove of the explosion-proof valve is located on the bottom wall of the buffer groove on the valve body, ensuring that the opening area of the explosion-proof valve is maximized, increasing the pressure relief rate, and being able to quickly relieve pressure when the battery cell is thermally runaway, reducing the risk of battery cell explosion; and the notched groove is located on the bottom wall of the buffer groove, and the residual thickness of the notched groove is bound to be thinner than the bottom wall thickness of the buffer groove, while ensuring the buffering effect of the buffer groove, it can ensure that when the internal pressure of the battery cell increases, the notched groove cracks instead of the buffer groove.
[0010] In an optional embodiment, the notched groove forms a continuous closed loop; the notched groove includes a deep groove segment and a shallow groove segment, and the residual thickness of the deep groove segment is smaller than the residual thickness of the shallow groove segment.
[0011] Beneficial effects: The notched groove includes a deep groove section and a shallow groove section. The deep groove section serves as a bursting section, and the shallow groove section can serve as a connecting part. When the deep groove section of the explosion-proof valve cracks, the shallow section can still connect the central part and the peripheral part of the valve body, preventing the central part of the valve body from flying out under the action of internal pressure and causing danger; and under the same opening pressure, the groove depth of the continuous closed-loop notched groove can be shallower than the depth of the non-closed-loop notch in the related art, and the groove depth including the deep groove section can be set shallower, so that the processing accuracy requirements are lower, thereby effectively reducing the production cost.
[0012] In an optional embodiment, there is a step transition between the deep groove section and the shallow groove section; or there is a smooth transition between the deep groove section and the shallow groove section.
[0013] Beneficial effects: A step transition is adopted between the deep groove section and the shallow groove section, which simplifies the processing technology and saves time and effort; a smooth transition is adopted between the deep groove section and the shallow groove section, which can effectively reduce the transition stress and improve the stability of the explosion-proof valve.
[0014] In an optional embodiment, the cross-sectional shape of the buffer groove is U-shaped.
[0015] Beneficial effects: The side wall of the U-shaped groove acts as a structure for buffering, absorbing vibration and deformation, thereby reducing the vibration transmitted to the bottom wall, reducing the stress generated at the notched groove, improving the buffering performance, and keeping the notched groove intact during installation. In addition, the U-shaped buffer groove has a simple structure and is easy to produce.
[0016] In an optional embodiment, the cross-sectional shape of the notch groove is an inverted trapezoid.
[0017] Beneficial effect: The cross section of the notched groove is inverted trapezoidal, so the central cracked part of the valve body can be more easily disengaged during pressure relief, thereby improving the bursting effect and the pressure relief effect.
[0018] In an optional embodiment, at least the cross-sectional shape of the deep groove section is an inverted trapezoid.
[0019] Beneficial effect: at least the cross-sectional shape of the deep groove section is set to an inverted trapezoid, which improves the bursting effect. When the cross-sectional shapes of the deep groove section and the shallow groove section are both set to an inverted trapezoid, the same mold can be used for production, thereby reducing production costs.
[0020] In an optional embodiment, the length of the shallow groove segment accounts for 1 / 10 to 1 / 3 of the total length of the scoring groove.
[0021] Beneficial effect: The deep groove section is used as the bursting section for pressure relief. Therefore, in order to ensure the pressure relief effect, the length of the shallow groove section should not be too long, otherwise it will affect the opening of the explosion-proof valve or cause the opening pressure of the explosion-proof valve to increase. When the length of the shallow groove section accounts for 1 / 10 to 1 / 3 of the total length of the scored groove, it will neither affect the opening of the explosion-proof valve nor cause the opening pressure of the explosion-proof valve to increase. Moreover, the shallow groove section can still ensure the connection between the central part and the peripheral part of the valve body after the deep groove section cracks, thereby preventing the central part from flying out and causing damage.
[0022] In an optional embodiment, the notched grooves are arranged continuously and are not closed loops.
[0023] Beneficial effects: the notched grooves are continuously arranged and are not closed loops, and have a physical connection portion. After the explosion-proof valve is cracked, the connection between the central part and the peripheral part of the explosion-proof valve is achieved through the connection portion, thereby improving the safety after pressure relief.
[0024] In a second aspect, the utility model provides a battery core assembly, comprising:
[0025] The positive electrode aluminum sheet is provided with a through groove;
[0026] The explosion-proof valve described in any one of the above items is sealed and installed in the through groove.
[0027] Beneficial effect: Since the battery cell assembly includes the explosion-proof valve of the utility model, it has the same technical effect as the explosion-proof valve, which will not be described in detail here.
[0028] In a third aspect, the utility model provides a battery, comprising the above-mentioned battery cell assembly.
[0029] Beneficial effect: Since the battery includes the battery cell assembly of the utility model, it has the same technical effect as the battery cell assembly, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0031] Figure 1 This is a schematic diagram of the three-dimensional structure of an explosion-proof valve according to an embodiment of the utility model;
[0032] Figure 2 This is a front view of an explosion-proof valve according to an embodiment of the utility model;
[0033] Figure 3A top view of an explosion-proof valve according to an embodiment of the utility model;
[0034] Figure 4 for Figure 3 Middle AA section view;
[0035] Figure 5 for Figure 3 Middle BB section view;
[0036] Figure 6 for Figure 5 A schematic diagram of the partially enlarged structure of the J part;
[0037] Figure 7 for Figure 5 A schematic diagram of the partially enlarged structure of part I;
[0038] Figure 8 The schematic diagram of the structure of the connection between the deep groove section and the shallow groove section of an explosion-proof valve according to an embodiment of the utility model shows a step transition state;
[0039] Fig. 9 The schematic diagram of the structure of the connection between the deep groove section and the shallow groove section of an explosion-proof valve according to an embodiment of the utility model shows a smooth transition state;
[0040] Fig.10 This is a schematic diagram of an exploded structure of an upper cover of a battery cell assembly according to an embodiment of the utility model;
[0041] Fig.11 This is a front view of an upper cover of a battery cell assembly according to an embodiment of the utility model;
[0042] Fig.12 It is a left side view of an upper cover of a battery cell assembly according to an embodiment of the utility model;
[0043] Fig.13 A bottom view of an upper cover of a battery cell assembly according to an embodiment of the utility model;
[0044] Fig.14 A top view of an upper cover of a battery cell assembly according to an embodiment of the utility model;
[0045] Fig.15 for Fig.14 Middle DD section view;
[0046] Fig.16 for Fig.14 Middle CC section view.
[0047] Description of reference numerals:
[0048] 1. Positive pole;
[0049] 2. Sealing ring;
[0050] 3. Plastic under the positive electrode;
[0051] 4. Positive aluminum sheet;
[0052] 41. Through slot;
[0053] 5. Plastic on the positive electrode;
[0054] 6. Riveting block;
[0055] 7. Explosion-proof valve;
[0056] 71. Valve body;
[0057] 72. Buffer tank;
[0058] 73, notched groove; 731, deep groove section; 732, shallow groove section; 733, transition section;
[0059] 74. Overlap edge;
[0060] 8. Valve film. DETAILED DESCRIPTION
[0061] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0062] In the description of the utility model, it should be noted that, unless otherwise specified, "multiple" means two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0063] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.
[0064] According to the specific embodiment of the utility model, Figure 1-Figure 9 As shown, an explosion-proof valve 7 is provided, comprising:
[0065] The valve body 71 has an inner side and an outer side, wherein the inner side corresponds to the interior of the battery cell;
[0066] The buffer groove 72 is provided on the valve body 71 and is recessed toward the inner side of the valve body 71 to form an annular groove structure;
[0067] The notched groove 73 is disposed on the bottom wall of the buffer groove 72 along the extending direction of the buffer groove 72 .
[0068] Beneficial effects: The buffer groove 72 formed on the valve body 71 can absorb vibration energy, effectively reduce the stress on the notched groove 73 under the conditions of battery cell production, pack assembly and vehicle vibration, and the notched groove 73 is not easy to fail due to fatigue cracking, ensuring the reliability of the explosion-proof valve 7. The notched groove 73 of the explosion-proof valve 7 is located on the bottom wall of the buffer groove 72 on the valve body 71, ensuring that the opening area of the explosion-proof valve 7 is maximized, improving the pressure relief rate, and can quickly relieve pressure when the battery cell is thermally runaway, reducing the risk of battery cell explosion; and the notched groove 73 is located on the bottom wall of the buffer groove 72, and the residual thickness of the notched groove 73 is bound to be thinner than the bottom wall thickness of the buffer groove 72, while ensuring the buffering effect of the buffer groove 72, it can ensure that the notched groove 73 cracks instead of the buffer groove 72 when the internal pressure of the battery cell increases.
[0069] It should be noted that the residual thickness refers to the thickness of the wall where the notched groove 73 is opened (the wall thickness of the bottom wall of the buffer groove 72 in the present invention) minus the groove depth of the notched groove 73. The residual thickness of the notched groove 73 is less than the thickness of the bottom wall of the buffer groove 72.
[0070] Specifically, the wall surface of the valve body 71 is recessed downward to form a buffer groove 72 , which has a simple structure and a simple molding process. The buffer groove 72 has high structural rigidity and good impact resistance, and can effectively buffer vibration propagation to the notched groove 73 .
[0071] In one embodiment, the buffer groove 72 is located near the edge of the valve body 71 .
[0072] The buffer groove 72 is arranged near the edge of the valve body 71 , which can ensure the buffer length of the buffer groove 72 and increase the pressure relief area of the explosion-proof valve 7 , thereby ensuring the pressure relief speed.
[0073] In an optional embodiment, the notched groove 73 forms a continuous closed loop; the notched groove 73 includes a deep groove segment 731 and a shallow groove segment 732 , and the residual thickness of the deep groove segment 731 is less than the residual thickness of the shallow groove segment 732 .
[0074] Beneficial effect: The notched groove 73 includes a deep groove section 731 and a shallow groove section 732. The deep groove section 731 serves as a bursting section, and the shallow groove section 732 can serve as a connecting part. When the deep groove section 731 of the explosion-proof valve 7 is cracked, the shallow section can still connect the central part and the peripheral part of the valve body, preventing the central part of the valve body from flying out under the action of internal pressure and causing danger; and under the same opening pressure, the groove depth of the continuous closed-loop notched groove 73 can be shallower than the depth of the non-closed-loop notch in the related art, and the groove depth including the deep groove section 731 can be set shallower, so that the processing accuracy requirements are lower, thereby effectively reducing the production cost.
[0075] like Figure 6 and Figure 7 As shown, in this embodiment, the residual thickness T1 of the deep groove section 731 and the residual thickness T2 of the shallow groove section 732 of the notched groove 73 are both smaller than the wall thickness T0 of the bottom wall of the buffer groove 72, that is, T1 <T2<T0。
[0076] In some optional embodiments, the deep groove section 731 and the shallow groove section 732 have a step transition, see Figure 8 .
[0077] A step transition is adopted between the deep groove section 731 and the shallow groove section 732, which simplifies the processing technology and saves time and effort.
[0078] In some other embodiments, such as Fig. 9 As shown, the deep groove section 731 and the shallow groove section 732 are smoothly transitioned through the transition section 733 . The smooth transition between the deep groove section 731 and the shallow groove section 732 can effectively reduce the transition stress and improve the stability of the explosion-proof valve 7 .
[0079] In some optional embodiments, the cross-sectional shape of the buffer groove 72 is U-shaped.
[0080] The side wall of the U-shaped groove serves as a structure for buffering, absorbing vibration and deformation, thereby reducing the vibration transmitted to the bottom wall, reducing the stress generated at the notched groove 73, avoiding failure caused by stress concentration at the notched groove 73, improving the buffering performance, and keeping the notched groove 73 intact during the installation process. In addition, the U-shaped buffer groove 72 has a simple structure and is easy to produce.
[0081] In some optional embodiments, the cross-sectional shape of the notch groove 73 is an inverted trapezoid.
[0082] The cross section of the notched groove 73 is in an inverted trapezoidal shape, so that the central cracked portion of the valve body 71 can be more easily disengaged during pressure relief, thereby enhancing the bursting effect and the pressure relief effect.
[0083] In some optional embodiments, at least the cross-sectional shape of the deep groove section 731 is an inverted trapezoid.
[0084] At least the cross-sectional shape of the deep groove section 731 is set to an inverted trapezoid to improve the bursting effect. When the cross-sectional shapes of the deep groove section 731 and the shallow groove section 732 are both set to an inverted trapezoid, the same mold can be used for production, thereby reducing production costs.
[0085] In some optional embodiments, the length of the shallow groove section 732 accounts for 1 / 10 to 1 / 3 of the total length of the scoring groove 73 .
[0086] The deep groove section 731 is used as a bursting section for pressure relief. Therefore, in order to ensure the pressure relief effect, the length of the shallow groove section 732 should not be too long, otherwise it will affect the opening of the explosion-proof valve 7, or cause the opening pressure of the explosion-proof valve 7 to increase. When the length of the shallow groove section 732 accounts for 1 / 10 to 1 / 3 of the total length of the notched groove 73, it will neither affect the opening of the explosion-proof valve 7 nor cause the opening pressure of the explosion-proof valve 7 to increase. Moreover, after the deep groove section 731 cracks, the shallow groove section 732 can still ensure the connection between the central part and the peripheral part of the valve body, thereby preventing the central part from flying out and causing damage.
[0087] In some optional embodiments, the notched groove 73 is continuously arranged and is not a closed loop.
[0088] The notched grooves 73 are continuously arranged and are not closed loops. There is a physical connection portion between the central portion and the peripheral portion of the explosion-proof valve 7. After the explosion-proof valve 7 is cracked, the central portion and the peripheral portion of the explosion-proof valve 7 are connected through the connection portion, thereby improving safety after pressure relief.
[0089] However, in some other embodiments, the groove depth of the notched groove 73 of the non-closed loop explosion-proof valve 7 may also be gradual. The notched groove 73 gradually changes from one end to the other end of the explosion-proof valve 7, which can reduce the opening pressure of the explosion-proof valve 7 and improve the bursting performance. The specific depths of the deepest and shallowest parts of the groove depth can be designed according to the bursting pressure.
[0090] In one embodiment, the buffer groove 72 forms at least one annular groove, and the notched groove 73 is disposed on the bottom wall of at least one of the annular grooves.
[0091] The buffer groove 72 forms at least one annular groove, forming a complete buffer isolation zone on the vibration propagation path, and the buffering effect is better.
[0092] Specifically, a plurality of nested annular grooves can be provided as required to improve the buffering effect, and the notched groove 73 is provided on the bottom wall of one of the annular grooves. Preferably, the notched groove 73 is provided on the bottom wall of the buffer groove 72 of the outermost circle to ensure the pressure relief area and pressure relief effect. It can also be selected and provided according to the battery capacity, pressure relief needs, etc., with high flexibility.
[0093] In one embodiment, the shape of the buffer groove 72 matches the shape of the outer contour of the valve body 71 .
[0094] The shape of the buffer groove 72 matches the shape of the outer contour of the valve body 71 , and the buffering consistency in all directions of 360 degrees is good, and the reliability is high.
[0095] In one embodiment, an overlapped edge 74 is formed at the edge of the valve body 71, and the buffer groove 72 is disposed adjacent to or spaced from the overlapped edge 74. Preferably, the overlapped edge 74 is formed around the circumferential edge of the buffer groove 72, so that the structure is more compact.
[0096] In some other embodiments, under the premise of meeting the pressure relief requirements, the buffer groove 72 may also be spaced apart from the overlapping edge 74 to further improve the buffer reliability.
[0097] The valve body 71 is welded to the edge of the through slot 41 on the positive aluminum sheet 4 through the overlapping edge 74 at the edge. The thickness of the overlapping edge 74 is designed according to the welding reliability requirement. The greater the thickness, the higher the reliability.
[0098] According to an embodiment of the present utility model, on the other hand, Figure 10-Figure 16 As shown, a battery cell assembly is also provided, including:
[0099] Positive column 1;
[0100] Sealing ring 2;
[0101] Plastic under the positive electrode 3;
[0102] The positive electrode aluminum sheet 4 is provided with a through slot 41;
[0103] Plastic 5 on the positive electrode;
[0104] Riveting block 6;
[0105] An explosion-proof valve 7, which is sealed and installed in the through groove 41; and
[0106] Valve film 8.
[0107] Since the battery cell assembly includes the explosion-proof valve 7 of the utility model, the buffer groove 72 of the explosion-proof valve 7 can effectively absorb vibration energy, reduce the stress on the notched groove 73 during battery cell production, pack assembly and vehicle vibration conditions, and the notched groove 73 is not prone to fatigue cracking and failure, ensuring the reliability of the explosion-proof valve 7. The notched groove 73 of the explosion-proof valve 7 is located on the wall surface of the buffer groove 72 on the valve body 71, ensuring that the opening area design of the explosion-proof valve 7 is maximized, improving the pressure relief rate, and being able to quickly relieve pressure when the battery cell is thermally runaway, reducing the risk of battery cell explosion.
[0108] According to an embodiment of the present invention, in another aspect, a battery is provided, comprising the above-mentioned battery cell assembly.
[0109] Since the battery includes the battery cell assembly of the utility model, it has the same technical effect as the battery cell assembly, which will not be described in detail here. The safety and reliability of the battery are further improved, and the safety of new energy vehicles is also greatly improved after the battery is installed.
[0110] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.
Claims
1. An explosion-proof valve, characterized in that: include: A valve body (71) having an inner side and an outer side; A buffer groove (72) is provided on the valve body (71) and is recessed toward the inner side of the valve body (71) to form an annular groove structure; The notched groove (73) is arranged in a ring shape on the bottom wall of the buffer groove (72) along the extension direction of the buffer groove (72).
2. The explosion-proof valve according to claim 1, characterized in that: The notched groove (73) forms a continuous closed loop; the notched groove (73) comprises a deep groove section (731) and a shallow groove section (732), and the residual thickness of the deep groove section (731) is smaller than the residual thickness of the shallow groove section (732).
3. The explosion-proof valve according to claim 2, characterized in that: There is a step transition between the deep groove section (731) and the shallow groove section (732); or there is a smooth transition between the deep groove section (731) and the shallow groove section (732).
4. The explosion-proof valve according to claim 1, characterized in that: The cross-sectional shape of the buffer groove (72) is U-shaped.
5. The explosion-proof valve according to claim 1, characterized in that: The cross-sectional shape of the notched groove (73) is an inverted trapezoid.
6. The explosion-proof valve according to claim 2, characterized in that: At least the cross-sectional shape of the deep groove section (731) is an inverted trapezoid.
7. The explosion-proof valve according to claim 2, characterized in that: The length of the shallow groove section (732) accounts for 1 / 10 to 1 / 3 of the total length of the notched groove (73).
8. The explosion-proof valve according to claim 1, characterized in that: The notched grooves (73) are arranged continuously and are not closed loops.
9. A battery cell assembly, characterized in that: include: The positive electrode aluminum sheet (4) is provided with a through groove (41); The explosion-proof valve (7) according to any one of claims 1 to 8, wherein the explosion-proof valve (7) is sealed and installed in the through groove (41).
10. A battery, characterized in that: Comprising the battery core assembly as claimed in claim 9.