Blade sodium battery with high safety

Abstract

The utility model discloses a blade sodium battery with high safety, and belongs to the technical field of batteries. Comprising a square shell, one end of the square shell is hermetically covered with a positive electrode cover plate, a positive electrode exhaust hole is formed in the positive electrode cover plate, a positive electrode containing groove is formed in the area corresponding to the positive electrode exhaust hole, and the positive electrode containing groove is used for containing a positive electrode anti-explosion valve; a negative electrode cover plate covers the other end of the square shell in a sealing mode, a negative electrode exhaust hole is formed in the negative electrode cover plate, and a negative electrode containing groove is formed in the area corresponding to the negative electrode exhaust hole and used for containing a negative electrode anti-explosion valve. Compared with the existing single explosion-proof valve, the positive / negative explosion-proof valve is equivalent to adding a pressure relief channel, so that a better explosion-proof effect is achieved, the safety level of the blade sodium battery is improved, the explosion risk of the battery is reduced, and the positive / negative explosion-proof valve is arranged on different sides of the positive / negative pole, so that the internal gas pressure relief path is reduced, and the safety of the blade sodium battery is improved. And the pressure relief safety is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a blade sodium battery with high safety. Background Art

[0002] Sodium-ion batteries (SIBs) show great potential as large-scale energy storage devices due to their low cost and similar physical and chemical properties to commercial lithium-ion batteries. Safety is a top priority in the research, development, and production of SIBs. Due to their electrochemical properties, SIBs can experience severe internal degradation after long-term cycling or exposure to harsh operating conditions such as high or low temperatures, leading to sodium precipitation. The precipitated sodium reacts with the electrolyte, producing more severe gassing than in lithium batteries, leading to increased internal pressure. The presence of explosion-proof valves, while providing explosion-proof protection, can reduce battery safety.

[0003] Then, the current structural design of the blade sodium battery refers to the lithium battery. Generally, a single explosion-proof valve is provided on the top of the cover body. When the sodium battery produces a lot of gas due to thermal runaway or other conditions, the explosion may occur before the pressure can be released in time after the explosion-proof valve on the top of the sodium battery is opened, thus causing great losses.

[0004] Therefore, as sodium batteries produce a lot of gas, how to improve the safety performance of sodium batteries is an important technical issue that needs to be solved urgently. Utility Model Content

[0005] In order to solve the problems existing in the existing single explosion-proof valve blade sodium battery, the purpose of the present invention is to provide a blade sodium battery with high safety, improve the safety level of the blade sodium battery, and reduce its safety risks. To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0006] A highly safe blade sodium battery comprises a square shell, wherein a sealing cover at one end of the square shell is provided with a positive electrode cover plate, a positive electrode exhaust hole is provided on the positive electrode cover plate, a positive electrode receiving groove is formed in an area corresponding to the positive electrode exhaust hole, and the positive electrode receiving groove is used to accommodate a positive electrode explosion-proof valve; a sealing cover at the other end of the square shell is provided with a negative electrode cover plate, a negative electrode exhaust hole is provided on the negative electrode cover plate, a negative electrode receiving groove is formed in an area corresponding to the negative electrode exhaust hole, and the negative electrode receiving groove is used to accommodate a negative electrode explosion-proof valve.

[0007] As a further solution of the present invention: a positive pole is provided in the middle of the positive cover plate, and a liquid injection hole is provided on the end of the positive cover plate away from the positive explosion-proof valve.

[0008] As a further solution of the present invention: a negative pole is provided in the middle position of the negative electrode cover.

[0009] As a further solution of the present invention: the positive pole explosion-proof valve and the negative pole explosion-proof valve both include a bursting surface and a welding surface, the welding surface is arranged around the edge of the bursting surface, and the thickness of the welding surface is greater than the thickness of the bursting surface.

[0010] As a further solution of the present invention: the surface of the blasting surface is formed with an inwardly concave outer peripheral notch, and the outer peripheral notch is located in the area of ​​the blasting surface close to the welding surface.

[0011] As a further solution of the present invention: an inwardly recessed reinforcement notch is formed in the middle of the blasting surface, and the depth of the reinforcement notch is smaller than the depth of the outer peripheral notch.

[0012] As a further solution of the present invention: the reinforcement notch is formed into an S-shaped curve structure.

[0013] The utility model has the following beneficial effects:

[0014] The utility model provides a positive pole explosion-proof valve on the positive pole cover plate and a negative pole explosion-proof valve on the negative pole cover plate. Compared with the existing single explosion-proof valve, this is equivalent to adding a pressure relief channel, which plays a better explosion-proof role, improves the safety level of the blade sodium battery, and reduces the risk of battery explosion. In addition, the positive / negative pole explosion-proof valves of the utility model are on different sides of the positive / negative poles, which reduces the internal gas pressure relief path and improves the pressure relief safety.

[0015] The utility model forms an outer peripheral notch by recessing at least a portion of the area of ​​the explosion surface close to the welding surface. The local thinning of the outer peripheral notch can form a path guide for the opening of the explosion surface, so that the positive / negative explosion-proof valves of the battery are conveniently opened along the path corresponding to the outer peripheral notch; it is ensured that when thermal runaway occurs, the positive / negative explosion-proof valves preferentially explode along the path defined by the outer peripheral notch, thereby ensuring the exhaust area of ​​the positive / negative explosion-proof valves, and after the explosion, there are fewer burrs on the opening path formed along the outer peripheral notch, and the opening is relatively smooth. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the three-dimensional structure (positive electrode) of a blade sodium battery with high safety in the utility model;

[0018] Figure 2 This is a schematic diagram of the three-dimensional structure (negative electrode) of a blade sodium battery with high safety in the utility model;

[0019] Figure 3 This is a top view schematic diagram of the positive electrode cover structure of the utility model;

[0020] Figure 4This is a top view schematic diagram of the negative electrode cover structure of the utility model;

[0021] Figure 5 This is a top view of the positive pole explosion-proof valve / negative pole explosion-proof valve structure of the utility model;

[0022] Figure 6 It is a schematic cross-sectional view of the positive pole explosion-proof valve / negative pole explosion-proof valve structure of the utility model.

[0023] In the figure: 1. Square shell; 2. Positive cover; 3. Positive explosion-proof valve; 4. Negative cover; 5. Negative explosion-proof valve; 6. Positive pole; 7. Liquid injection hole; 8. Negative pole; 9. Burst surface; 10. Welding surface; 11. Outer perimeter notch; 12. Reinforcement notch. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", "front", "back", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, and a specific direction structure and operation. Therefore, they cannot be understood as a limitation on the present invention.

[0026] In addition, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances.

[0027] Example 1

[0028] See also Figure 1 、 Figure 3As shown, embodiment 1 of the present invention provides a blade sodium battery with high safety, including an aluminum square shell 1, a sealing cover at one end of the square shell 1 is provided with a positive cover plate 2, a positive exhaust hole is provided on the positive cover plate 2, and a positive receiving groove is formed in the area corresponding to the positive exhaust hole, the positive receiving groove is used to accommodate a positive explosion-proof valve 3, a positive pole column 6 is provided in the middle position of the positive cover plate 2, and an injection hole 7 is provided on the end of the positive cover plate 2 away from the positive explosion-proof valve 3.

[0029] See also Figure 2 、 Figure 4 As shown, in this embodiment, the sealing cover at the other end of the square shell 1 is provided with a negative cover plate 4, a negative exhaust hole is opened on the negative cover plate 4, and a negative receiving groove is formed in the area corresponding to the negative exhaust hole. The negative receiving groove is used to accommodate the negative explosion-proof valve 5, and a negative pole 8 is provided in the middle position on the negative cover plate 4.

[0030] It should be noted that the pressure required for the positive electrode explosion-proof valve 3 and the negative electrode explosion-proof valve 5 to burst is less than the bursting pressure of the weld of the square shell 1, and is greater than the pressure inside the battery at the end of a normal cycle.

[0031] The present invention makes full use of the design features of the tabs on both sides of the aluminum shell of the blade battery, and sets a positive pole explosion-proof valve 3 on the positive pole cover plate 2, and sets a negative pole explosion-proof valve 5 on the negative pole cover plate 4. Compared with the existing single explosion-proof valve, it is equivalent to adding a pressure relief channel, which plays a better explosion-proof role, improves the safety level of the blade sodium battery, and reduces the risk of battery explosion. In addition, the positive / negative pole explosion-proof valves 5 of the present invention are on different sides of the positive / negative pole column 8, which reduces the internal gas pressure relief path and has higher pressure relief safety.

[0032] Example 2

[0033] See also Figure 5 、 Figure 6 As shown, embodiment 2 of the present invention provides a blade sodium battery with high safety, including a square shell 1, a sealing cover at one end of the square shell 1 is provided with a positive cover plate 2, a positive exhaust hole is opened on the positive cover plate 2, and a positive electrode receiving groove is formed in the area corresponding to the positive exhaust hole, and the positive electrode receiving groove is used to accommodate a positive explosion-proof valve 3; a sealing cover at the other end of the square shell 1 is provided with a negative cover plate 4, a negative exhaust hole is opened on the negative cover plate 4, and a negative electrode receiving groove is formed in the area corresponding to the negative exhaust hole, and the negative electrode receiving groove is used to accommodate a negative explosion-proof valve 5.

[0034] On the basis of Example 1, the improvement of Example 2 is that: the positive explosion-proof valve 3 and the negative explosion-proof valve 5 both include a bursting surface 9 and a welding surface 10, the welding surface 10 is arranged around the edge of the circumference of the bursting surface 9, and the thickness of the welding surface 10 is greater than the thickness of the bursting surface 9.

[0035] By setting a larger thickness welding surface 10, the welding requirements are met, the connection firmness of the battery positive / negative explosion-proof valve 5 after welding is ensured, the overall structural strength of the battery explosion-proof valve is improved, and the airtightness requirements after welding are met, while at the same time, the weight is not increased too much as possible; by setting a smaller thickness blasting surface 9, on the one hand, the sealing requirements of the battery in normal use can be guaranteed, and on the other hand, it can be ensured that the blasting surface 9 can be smoothly exploded when under pressure, which is convenient for exhaust.

[0036] Furthermore, an inwardly recessed outer peripheral notch 11 is formed on the surface of the blasting surface 9 , and the outer peripheral notch 11 is located in a region of the blasting surface 9 close to the welding surface 10 .

[0037] By recessing at least a portion of the blasting surface 9 near the welding surface 10 to form an outer peripheral notch 11, the local thinning of the outer peripheral notch 11 can form a path guide for the opening of the blasting surface 9, making it convenient for the positive / negative pole explosion-proof valve 5 of the battery to be opened along the path corresponding to the outer peripheral notch 11; ensuring that the positive / negative pole explosion-proof valve 5 will preferentially explode from the path defined by the outer peripheral notch 11 when thermal runaway occurs, thereby ensuring the exhaust area of ​​the positive / negative pole explosion-proof valve 5, and after the explosion, there are fewer burrs on the opening path formed along the outer peripheral notch 11, and the opening is relatively smooth.

[0038] Furthermore, an inwardly recessed reinforcement notch 12 is formed in the middle of the surface of the blasting surface 9. The depth of the reinforcement notch 12 is less than the depth of the outer peripheral notch 11. The reinforcement notch 12 may be, but is not limited to, an S-shaped curve structure. The reinforcement notch 12 can enhance the structural strength of the blasting surface 9, reduce the deformation of the blasting surface 9 during normal use, and ensure structural strength. By limiting the depth of the reinforcement notch 12 to be less than the depth of the outer peripheral notch 11, it can be ensured that the battery positive / negative pole explosion-proof valve 5 explodes along the outer peripheral notch 11, using the guide path formed by the outer peripheral notch 11 as the opening path, and will not explode using the reinforcement notch 12 as the guide path. The opening conditions of the battery positive / negative pole explosion-proof valve 5 are precisely controllable, adapted to the battery cell manufacturing process, meeting the opening requirements of specific working conditions, and improving safety.

[0039] The above detailed description of the preferred embodiments of the present invention should not be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A blade sodium battery with high safety, comprising a square housing (1), characterized in that: A positive electrode cover plate (2) is provided on one end of the square housing (1) and a positive electrode exhaust hole is provided on the positive electrode cover plate (2). A positive electrode receiving groove is formed in an area corresponding to the positive electrode exhaust hole. The positive electrode receiving groove is used to accommodate a positive electrode explosion-proof valve (3). A negative electrode cover plate (4) is provided on the other end of the square housing (1). A negative electrode exhaust hole is provided on the negative electrode cover plate (4). A negative electrode receiving groove is formed in an area corresponding to the negative electrode exhaust hole. The negative electrode receiving groove is used to accommodate a negative electrode explosion-proof valve (5). The positive pole explosion-proof valve (3) and the negative pole explosion-proof valve (5) both comprise a bursting surface (9) and a welding surface (10), the welding surface (10) is arranged around the edge of the bursting surface (9), and the thickness of the welding surface (10) is greater than the thickness of the bursting surface (9); The surface of the blasting surface (9) is formed with an inwardly recessed outer peripheral notch (11), and the outer peripheral notch (11) is located in a region of the blasting surface (9) close to the welding surface (10); The blasting surface (9) is also provided with an inwardly recessed reinforcement notch (12) in the middle thereof, wherein the depth of the reinforcement notch (12) is less than the depth of the outer peripheral notch (11); The reinforcing notch (12) is in an S-shaped curve structure.

2. The highly safe blade sodium battery according to claim 1, characterized in that: A positive pole column (6) is provided in the middle of the positive cover plate (2), and a liquid injection hole (7) is provided on one end of the positive cover plate (2) away from the positive explosion-proof valve (3).

3. The highly safe blade sodium battery according to claim 2, characterized in that: A negative pole post (8) is provided at a middle position on the negative electrode cover plate (4).

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