A power battery casing and a secondary battery

Abstract

This invention proposes a power battery casing and a secondary battery, belonging to the field of batteries. The casing includes a first casing wall and several second casing walls forming a casing. A pressure relief hole is provided on the first casing wall. A first boss protrudes into the casing from the first casing wall, and a second boss protrudes outward from the first boss. Alternatively, at least one first boss and one second boss protrude into the casing from the first casing wall, with the first and second bosses spaced apart. The pressure relief hole is located on one of the second bosses. This invention provides a first boss and a second boss with a height difference on the casing wall where the pressure relief hole is located, increasing the distance between the pressure relief device and the internal core of the battery and the external environment. This avoids the safety hazard of casing explosion due to the pressure relief device's inability to release pressure in time, and also mitigates the risk of electrolyte leakage due to damage to the pressure relief device caused by bumps and scratches caused by insufficient distance.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a power battery casing and a secondary battery. Background Technology

[0002] Existing thermoelectric batteries have pressure relief holes on the casing wall to reduce the safety risk of high-temperature gases being directly sprayed onto passengers in the event of thermal runaway. However, due to the relatively thin casing wall, the distance between the pressure relief device and internal / external contact objects is too small. On the one hand, when thermal runaway occurs, the small distance between the core and insulation components and the pressure relief hole can lead to internal gas blockage and poor pressure relief, causing safety hazards such as casing explosion. On the other hand, the small distance between the pressure relief device and external contact objects makes it easy for the device to be bumped or scratched during battery manufacturing or use, leading to internal electrolyte leakage. Summary of the Invention

[0003] In view of this, the present invention proposes a power battery casing and a secondary battery to solve the problem that the pressure relief hole on the battery is easily blocked due to the small distance between the internal core and the external environment.

[0004] The technical solution of the present invention is implemented as follows: The present invention provides a power battery housing, including a first housing wall and a plurality of second housing walls, forming a housing; wherein, a pressure relief hole is provided on the first housing wall; a first boss is provided on the first housing wall protruding into the housing, and a second boss is provided on the first boss protruding outward from the housing; or, at least one first boss and a second boss are provided on the first housing wall protruding into the housing, the first boss and the second boss being spaced apart; the pressure relief hole is provided on the second boss.

[0005] Based on the above technical solutions, when the second protrusion is located inside the first protrusion, a gap is left between the circumferential surface of the first protrusion and the inner surface of the adjacent second shell wall; when the second protrusion is located on the first shell wall and spaced apart from the first protrusion, gaps are left between the circumferential surface of the first protrusion and the inner surface of the adjacent second shell wall, as well as between the first protrusion and the second protrusion.

[0006] Furthermore, a groove is formed inside the first boss; when the second boss is set inside the first boss, the two ends of the groove are respectively connected to the gap and the second boss; when the second boss is set on the first shell wall and spaced apart from the first boss, the two ends of the groove are respectively connected to the two gaps.

[0007] Furthermore, several grooves are provided on both sides of the second boss, and these grooves are arranged in parallel.

[0008] Furthermore, when the second protrusion is located inside the first protrusion, a groove is provided on each side of the second protrusion, and tongue teeth are arranged at intervals on the inner walls of both sides of the groove, with the ends of the tongue teeth extending obliquely toward the second protrusion.

[0009] Furthermore, the groove depth is half the thickness of the first shell wall.

[0010] Based on the above technical solutions, the protrusion height of the second boss is less than that of the first boss.

[0011] Based on the above technical solutions, the first protrusion is rectangular, elliptical, or racetrack-shaped, and the second protrusion is also rectangular, elliptical, or racetrack-shaped.

[0012] Based on the above technical solutions, when the second protrusion is located inside the first protrusion, the second protrusion is located in the center of the first protrusion; when the second protrusion is located on the first shell wall and spaced apart from the first protrusion, there are two first protrusions arranged symmetrically, and the second protrusion is located between the two first protrusions.

[0013] On the other hand, the present invention also provides a secondary battery, including the power battery housing described above, and also including a core; a first shell wall is located at the bottom of the housing, and a plurality of second shell walls surround the side of the housing; the core is disposed inside the housing, the bottom of the core rests on a first protrusion, and the bottom of the core and the pressure relief holes on the second protrusion are spaced apart.

[0014] The power battery casing and secondary battery of the present invention have the following advantages over the prior art: (1) The present invention provides a first boss and a second boss with a height difference on the shell wall where the pressure relief hole is opened, which increases the distance between the pressure relief device and the internal core of the battery and the external environment of the battery. This not only avoids the safety hazard of shell explosion caused by the pressure relief device failing to release pressure in time, but also improves the risk of the pressure relief device being bumped or scratched due to the small distance, and avoids the risk of leakage of electrolyte inside the battery due to damage to the pressure relief device.

[0015] (2) The present invention provides a groove for venting in the first boss, which can increase the rate at which the gas inside the battery flows to the pressure relief device and improve the thermal safety performance of the battery.

[0016] (3) The present invention arranges tongue teeth on the inner wall of the groove to form an irregular directional guiding structure, guides the gas flow to the pressure relief device, and restricts the gas backflow to make it difficult to backflow, thereby improving the unidirectional guiding capability of the pressure relief gas. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a perspective view of the secondary battery of the present invention; Figure 2 This is a perspective view of the secondary battery of the present invention from another angle; Figure 3 This is a side sectional view of the power battery casing of the present invention; Figure 4 This is a half-sectional perspective view of the power battery casing of the present invention; Figure 5 This is a bottom view of the power battery casing of the present invention; Figure 6 This is a half-sectional perspective view of another embodiment of the power battery casing of the present invention; Figure 7 This is a bottom view of another embodiment of the power battery casing of the present invention; Figure 8 This is a side sectional view of another embodiment of the power battery housing of the present invention; Figure 9 This is a half-sectional perspective view of another embodiment of the power battery casing of the present invention. Figure 10 This is a bottom view of another embodiment of the power battery casing of the present invention.

[0019] In the figure: 1. First shell wall; 10. Pressure relief hole; 11. First boss; 12. Second boss; 13. Groove; 14. Tongue tooth; 2. Second shell wall; 20. Gap; 3. Core. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0026] like Figure 1 As shown, combined with Figure 2 and Figure 8 The present invention provides a power battery housing, comprising a first housing wall 1 and a plurality of second housing walls 2.

[0027] The first shell wall 1 and several second shell walls 2 are all made of aluminum plates, forming a shell that accommodates the core 3. The first shell wall 1 differs from the other shell walls in that it has a pressure relief hole 10. The pressure relief hole 10 is fitted with a pressure relief device, which has a weak point. When a certain pressure is reached inside the battery, the weak point cracks, allowing internal gas to escape and preventing the shell from bursting due to excessive internal pressure. In principle, the first shell wall 1 can be the bottom or side of the battery shell. When the battery core 3 is inserted into the shell, the distance between the core 3 and the inner wall of the shell is very small; the core 3 may even be pressed tightly against the inner wall. This means that the core 3 may adhere to the first shell wall 1 with the pressure relief hole 10, causing the pressure relief hole 10 to become blocked and preventing the smooth discharge of gas from the battery's internal walls.

[0028] Based on the above issues, please refer to Figure 2 In this embodiment, a first boss 11 protrudes into the housing from the first housing wall 1, and a second boss 12 protrudes outward from the first boss 11. A pressure relief hole 10 is disposed on the second boss 12. Since the protrusion directions of the first boss 11 and the second boss 12 are different, and the pressure relief hole 10 is disposed on the outwardly protruding second boss 12, even if the core 3 is tightly attached to the first boss 11, there is still a large gap between the pressure relief hole 10 on the second boss 12 and the surface of the core 3, ensuring that the gas inside the battery housing can be discharged normally and smoothly from the pressure relief hole 10. Alternatively, another design can be adopted, see [reference needed]. Figure 8 At least one first protrusion 11 and a second protrusion 12 are provided on the first shell wall 1 protruding inwards from the shell. The first protrusion 11 and the second protrusion 12 are spaced apart. Similarly, the pressure relief hole 10 is provided on the second protrusion 12. At this time, as long as there is a certain difference in the protrusion height between the first protrusion 11 and the second protrusion 12, then similarly, even if the core 3 is tightly attached to the first protrusion 11, the pressure relief hole 10 on the second protrusion 12 and the surface of the core 3 will have a large gap, ensuring that the gas inside the battery shell can be discharged normally and smoothly from the pressure relief hole 10. At the same time, since the second protrusion 12 is also an inward protrusion design, the pressure relief hole 10 on the second protrusion 12 will have a certain gap with the plane where the first shell wall 1 is located, thus ensuring that the pressure relief hole 10 is also a large gap from the external environment. This embodiment, through the above design, increases the distance between the pressure relief device and the internal core 3 of the battery, as well as the external environment of the battery. This avoids the safety hazard of the casing exploding due to the inability of the pressure relief device to release pressure in time, and also improves the risk of the pressure relief device being bumped or scratched due to the small distance, thus avoiding the risk of electrolyte leakage inside the battery caused by damage to the pressure relief device.

[0029] exist Figure 3In one embodiment shown, when the second protrusion 12 is disposed within the first protrusion 11, the first protrusion 11 protrudes inward while the second protrusion 12 protrudes outward. The area of ​​the first protrusion 11 is smaller than the area of ​​the first shell wall 1. A gap 20 is left between the peripheral surface of the first protrusion 11 and the inner surface of the adjacent second shell wall 2 to prevent the first protrusion 11 from occupying a large amount of internal space of the shell. Figure 8 In one embodiment shown, when the second protrusion 12 is disposed on the first shell wall 1 and spaced apart from the first protrusion 11, both the first protrusion 11 and the second protrusion 12 are concave. A gap 20 is left between the peripheral surface of the first protrusion 11 and the inner surface of the adjacent second shell wall 2, as well as between the first protrusion 11 and the second protrusion 12. This is also to avoid the first protrusion 11 and the second protrusion 12 occupying a large amount of internal space of the shell.

[0030] exist Figure 4 In one embodiment shown, a groove 13 is formed in the first boss 11; when the second boss 12 is disposed in the first boss 11, the two ends of the groove 13 are respectively connected to the gap 20 and the second boss 12; Figure 9 In one embodiment shown, when the second protrusion 12 is disposed on the first shell wall 1 and spaced apart from the first protrusion 11, the two ends of the groove 13 are respectively connected to two gaps 20. The groove 13 is integrally formed by die-cutting or machining of the shell, and its function is to allow the gas inside the shell to flow through the groove 13 into the second protrusion 12 and be discharged from the pressure relief hole 10 when the core 3 is tightly attached to the first protrusion 11 and covers the second protrusion 12.

[0031] exist Figure 5 In one embodiment shown, a plurality of grooves 13 are provided on both sides of the second boss 12, and the plurality of grooves 13 are arranged in parallel to improve the efficiency of pressure relief and exhaust.

[0032] exist Figure 6 and Figure 7 In one embodiment shown, when the second protrusion 12 is disposed within the first protrusion 11, a groove 13 is provided on each side of the second protrusion 12, and tongue teeth 14 are spaced apart on the inner walls of both sides of the groove 13, with the ends of the tongue teeth 14 extending obliquely toward the second protrusion 12; the arrangement of several tongue teeth 14 forms an irregular directional guiding structure inside the groove 13, which can guide the gas inside the shell to be directionally exhausted from both sides of the second protrusion 12 toward the pressure relief hole 10, thereby improving the exhaust rate.

[0033] exist Figure 3 or Figure 8 In one embodiment shown, the depth h of the groove 13 is half the thickness of the first shell wall 1. Although this reduces the wall thickness of the first shell wall 1, the parallel structure of several grooves 13 can enhance the structural strength of the first shell 1 and improve its compressive strength.

[0034] exist Figure 3 or Figure 8 In one embodiment shown, the protrusion height H2 of the second boss 12 is less than the protrusion height H1 of the first boss 11. Thus, when the core 3 is tightly attached to the first boss 11, the pressure relief hole 10 on the second boss 12 still has a certain height difference between it and the first boss 11. The height difference is H1-H2, which can meet the requirement of the gas inside the shell being discharged from the pressure relief hole 10.

[0035] exist Figure 5 or Figure 7 or Figure 10 In one embodiment shown, the first protrusion 11 is rectangular, elliptical, or racetrack-shaped, and the second protrusion 12 is also rectangular, elliptical, or racetrack-shaped, thereby adapting to battery casing designs of different specifications and sizes.

[0036] exist Figure 5 In one embodiment shown, when the second boss 12 is disposed within the first boss 11, the second boss 12 is located at the exact center of the first boss 11; Figure 10 In one embodiment shown, when the second protrusion 12 is disposed on the first shell wall 1 and spaced apart from the first protrusion 11, there are two first protrusions 11 and they are symmetrically arranged. The second protrusion 12 is disposed between the two first protrusions 11, which ensures that the gas inside the battery casing 1 can flow evenly to the pressure relief hole 10 located in the center of the first shell wall 1, thereby improving the pressure relief effect.

[0037] like Figure 1 As shown, combined with Figure 2 The present invention provides a secondary battery comprising a power battery housing according to any of the above embodiments, and further comprising a core 3; a first housing wall 1 is located at the bottom of the housing, and a plurality of second housing walls 2 surround the side of the housing; the core 3 is disposed inside the housing, the bottom of the core 3 rests on a first protrusion 11, and the bottom of the core 3 is spaced apart from the pressure relief hole 10 on the second protrusion 12.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power battery casing, characterized in that, include: The first shell wall (1) and several second shell walls (2) form the shell; The first shell wall (1) is provided with a pressure relief hole (10). A first boss (11) is provided on the first shell wall (1) protruding into the shell, and a second boss (12) is provided inside the first boss (11) protruding out of the shell. Alternatively, at least one first boss (11) and a second boss (12) are provided on the first shell wall (1) protruding into the shell, with the first boss (11) and the second boss (12) spaced apart. The pressure relief hole (10) is located on the second boss (12).

2. The power battery casing according to claim 1, characterized in that: When the second boss (12) is disposed inside the first boss (11), a gap (20) is left between the circumferential surface of the first boss (11) and the inner surface of the adjacent second shell wall (2). When the second protrusion (12) is disposed on the first shell wall (1) and spaced apart from the first protrusion (11), a gap (20) is left between the circumferential surface of the first protrusion (11) and the inner surface of the adjacent second shell wall (2) as well as between the first protrusion (11) and the second protrusion (12).

3. A power battery casing according to claim 2, characterized in that: The first boss (11) has a groove (13) inside; When the second boss (12) is disposed in the first boss (11), the two ends of the groove (13) are respectively connected to the gap (20) and the second boss (12). When the second boss (12) is disposed on the first shell wall (1) and spaced apart from the first boss (11), the two ends of the groove (13) are respectively connected to the two gaps (20).

4. A power battery casing according to claim 3, characterized in that: The second boss (12) has several grooves (13) on both sides, and the grooves (13) are arranged in parallel.

5. A power battery casing according to claim 3, characterized in that: When the second boss (12) is located inside the first boss (11), a groove (13) is provided on each side of the second boss (12), and tongue teeth (14) are arranged at intervals on the inner walls of both sides of the groove (13), with the ends of the tongue teeth (14) extending obliquely toward the second boss (12).

6. A power battery casing according to claim 3, characterized in that: The depth of the groove (13) is half the thickness of the first shell wall (1).

7. A power battery casing according to claim 1, characterized in that: The protrusion height of the second boss (12) is less than the protrusion height of the first boss (11).

8. A power battery casing according to claim 1, characterized in that: The first protrusion (11) is rectangular, elliptical or racetrack shaped, and the second protrusion (12) is also rectangular, elliptical or racetrack shaped.

9. A power battery casing according to claim 1, characterized in that: When the second protrusion (12) is disposed inside the first protrusion (11), the second protrusion (12) is located at the center of the first protrusion (11); When the second boss (12) is disposed on the first shell wall (1) and spaced apart from the first boss (11), there are two first bosses (11) and they are symmetrically disposed, and the second boss (12) is disposed between the two first bosses (11).

10. A secondary battery, characterized in that: The power battery casing includes any one of claims 1 to 9, and also includes a core (3). The first shell wall (1) is located at the bottom of the shell, and a plurality of second shell walls (2) surround the side of the shell; The core (3) is disposed inside the housing, with the bottom of the core (3) resting on the first boss (11), and the bottom of the core (3) being spaced apart from the pressure relief hole (10) on the second boss (12).

Images