Single cell battery

Abstract

This application discloses a single-cell battery, comprising: a cell, a casing, and a top cover assembly. The cell is assembled in the casing, and the top cover assembly seals the casing. The top cover assembly comprises: a top cover, a protective cover, and an explosion-proof valve stacked sequentially. The explosion-proof valve is connected to one side of the top cover and presses down on the protective cover. The top cover has an explosion-proof hole, and the protective cover passes through the explosion-proof hole to the other side of the top cover. The top cover has a first groove around the explosion-proof hole, located on the side of the top cover facing the cell. The edge of the protective cover is accommodated in the first groove, and the explosion-proof valve presses down on the edge of the protective cover. The protective cover includes a cover body and a fixing part. The cover body has the explosion-proof hole, and the fixing part surrounds the edge of the cover body and is accommodated in the first groove. The explosion-proof valve presses down on the fixing part. The explosion-proof valve is welded to the top cover to seal the explosion-proof hole. The protective cover of this application is securely fixed to the top cover by the explosion-proof valve, preventing displacement.

Description

Technical Field

[0001] This application relates to the technical field of top cover components, and more particularly to a single cell battery. Background Technology

[0002] The battery cell casing, top cover, and associated seals together form a sealed space containing components such as the core, electrolyte, active materials, insulating film, and various substances required for electrochemical energy conversion. During normal use, the battery cell slowly produces gas. Under abuse conditions (such as internal short circuits), this gas production can be violent, causing the pressure within the sealed space to rise continuously. Since the battery cell casing and top cover have limited pressure resistance, if the internal pressure continues to rise and exceeds the resistance limit, it can cause the battery cell to explode, posing a safety risk.

[0003] Therefore, a safe and reliable explosion-proof valve needs to be designed. Under set conditions, it should be opened by internal air pressure to release the internal gas and prevent the battery cell from exploding. The explosion-proof valve is installed on the top cover, covering the vent hole of the top cover. The explosion-proof valve needs to maintain a stable burst pressure. The grooves on the explosion-proof valve are sensitive to external mechanical forces, so a protective design must be installed on the outside of the explosion-proof valve. The commonly used protection method is to stick a plastic piece to the outside of the vent hole of the top cover with double-sided tape. The main problem with this method is that the double-sided tape has a limited bonding area, the plastic piece is easy to shift, and the double-sided tape is prone to aging, causing the piece to fall off, which is not effective in protecting the explosion-proof valve.

[0004] Application content

[0005] The purpose of this application is to provide a single-cell battery to solve the technical problem of explosion-proof valves being impacted by external mechanical forces.

[0006] To achieve the above objectives, this application adopts the following technical solution: a top cover assembly is provided, the top cover assembly includes: a top cover, a protective cover and an explosion-proof valve arranged in sequence, the explosion-proof valve is connected to one side of the top cover and the protective cover is pressed and fixed, the top cover has an explosion-proof hole, the protective cover passes through the explosion-proof hole to the other side of the top cover, and the explosion-proof valve seals the explosion-proof hole.

[0007] Optionally, the top cover is provided with an explosion-proof hole and a first groove, the edge of the protective cover is accommodated in the first groove, and the explosion-proof valve is pressed against the edge of the protective cover.

[0008] Optionally, the top cover ring has an explosion-proof hole with a second groove that nests with the first groove, and the edge of the explosion-proof valve is accommodated in the second groove.

[0009] Optionally, the protective cover includes a cover body and a fixing part. The cover body has an explosion-proof hole, the fixing part surrounds the edge of the cover body, the fixing part is accommodated in a first groove, and the explosion-proof valve presses against the fixing part.

[0010] Optionally, the side wall of the cover is provided with ventilation holes that extend beyond the top cover.

[0011] Optionally, the explosion-proof valve includes: a connecting part and a bursting part, the connecting part is surrounded by the edge of the bursting part, the connecting part is connected to one side of the top cover and a fixed protective cover is pressed on it, and the side of the bursting part facing the explosion-proof valve is provided with a groove; the groove includes a first bursting mark and a second bursting mark, both of which are arc-shaped, the first bursting mark and the second bursting mark are symmetrical about the center of the bursting part and are spaced apart from each other, and the first bursting mark and the second bursting mark are used to break under a preset pressure.

[0012] Optionally, the notch also includes a third blast mark, which is connected to the first and second blast marks respectively, and the third blast mark is symmetrical about the center of the blasting part.

[0013] Optionally, the notch also includes a first connecting mark and a second connecting mark, with the opposite ends of the first connecting mark connected to one end of the first blast mark and the second blast mark respectively, and the opposite ends of the second connecting mark connected to the other end of the first blast mark and the second blast mark respectively, and the first connecting mark and the second connecting mark are symmetrical about the center of the blasting part.

[0014] Optionally, the first blast mark and the second blast mark have the same depth, and the first connection mark and the second connection mark have the same depth.

[0015] To achieve the above objectives, this application adopts the following technical solution: a single battery cell is provided, which includes: a battery cell, a housing, and a top cover assembly of any one of the above, wherein the battery cell is assembled in the housing, and the top cover assembly seals the housing.

[0016] The beneficial effects of this application embodiment are as follows: The top cover assembly includes a top cover, a protective cover, and an explosion-proof valve stacked sequentially. The top cover seals the housing, the explosion-proof valve is connected to the side of the top cover facing the housing, and the protective cover is pressed and fixed thereon. The top cover has an explosion-proof hole, the explosion-proof valve seals the explosion-proof hole, and the protective cover extends through the explosion-proof hole to the side of the top cover away from the housing. The explosion-proof valve is used to open when the internal pressure of the housing continues to rise and exceeds the pressure resistance limit, releasing pressure to prevent the battery cell from exploding. The explosion-proof valve is relatively sensitive to external mechanical forces, and the protective cover protects the explosion-proof valve from external mechanical forces. In addition, the explosion-proof valve is pressed and fixed after being connected to the top cover, thereby preventing the protective cover from being unreliable due to adhesion to the top cover. Attached Figure Description

[0017] To more clearly illustrate the embodiments of this application or the technical solutions in the previous research and development, the drawings used in the description of the embodiments or the previous research and development will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is an exploded structural diagram of the single cell provided in this application;

[0019] Figure 2 This application provides Figure 1 A partial cross-sectional diagram of region A in the middle;

[0020] Figure 3 This is a schematic diagram of the cross-sectional structure of the protective cover provided in this application;

[0021] Figure 4 This is a structural schematic diagram of the explosion-proof valve provided in this application;

[0022] Figure 5 This application provides Figure 4 Schematic diagram of the cross-sectional structure of region B in the middle;

[0023] Figure 6 This is a top view of the explosion-proof valve provided in this application.

[0024] The diagram is marked as follows:

[0025] Single battery 100, Cell 20, Casing 30, Top cover assembly 10, Top cover 12, Explosion-proof hole 121, First groove 123, Second groove 125, Protective cover 14, Cover body 142, Vent hole 146, Fixing part 144, Explosion-proof valve 16, Connecting part 162, Explosion part 164, Score 166

[0026] First blast mark 161; Second blast mark 163; Third blast mark 165

[0027] First connection mark 167 Second connection mark 169 Detailed Implementation

[0028] The use of terms such as "first," "second," etc. in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0029] Please see Figure 1 , Figure 1 This is an exploded structural diagram of the single cell 100 provided in this application.

[0030] The single-cell battery 100 of this application includes: a cell 20, a housing 30, and a top cover assembly 10. The cell 20 is an energy storage device and is assembled in the housing 30. The top cover assembly 10 covers the housing 30 and is electrically connected to the cell 20 to assist in the introduction of electrical energy into the cell 20 and the extraction of energy from the cell 20.

[0031] Please see Figure 1 and Figure 2 , Figure 2 This application provides Figure 1 A schematic diagram of a partial cross-section of region A in the middle.

[0032] The top cover assembly 10 includes a top cover 12, a protective cover 14, and an explosion-proof valve 16 stacked sequentially. The top cover 12 covers the housing 30. The explosion-proof valve 16 is connected to the side of the top cover 12 facing the housing 30 and presses the protective cover 14 in place. The top cover 12 has an explosion-proof hole 121, which is covered by the explosion-proof valve 16. The protective cover 14 extends through the explosion-proof hole 121 to the side of the top cover 12 away from the housing 30. The explosion-proof valve 16 is used to open when the internal pressure of the housing 30 continues to rise and exceeds the pressure resistance limit, releasing pressure to prevent the battery cell 20 from exploding. The explosion-proof valve 16 is sensitive to external mechanical forces, and the protective cover 14 protects the explosion-proof valve 16 from external mechanical forces. In addition, the explosion-proof valve 16 is pressed in place by the protective cover 14 after being connected to the top cover 12, thereby preventing the protective cover 14 from being loosely attached to the top cover 12.

[0033] It is worth noting that the protective cover 14 can protect the explosion-proof valve 16 from external mechanical forces, but when the internal pressure of the housing 30 breaks through the explosion-proof valve 16, the protective cover 14 will also be directly broken through.

[0034] The protective cover 14 is made of plastic, such as PP, PE, PET, PPS, etc. The thickness of the top surface of the protective cover 14 ranges from 0.1mm to 0.7mm, for example, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm. This thickness range ensures that the top surface of the protective cover 14 has a certain mechanical strength to protect the explosion-proof valve 16, and also allows the top surface of the protective cover 14 to be opened by the hot gas flow ejected from inside the housing 30 when the explosion-proof valve 16 bursts and releases pressure, without blocking the explosion-proof hole 121.

[0035] In one embodiment, the top cover 12 has explosion-proof holes 121 with a first groove 123. The edge of the protective cover 14 is accommodated in the first groove 123, and the explosion-proof valve 16 presses against the edge of the protective cover 14. On the one hand, the first groove 123 serves to limit the movement of the protective cover 14; on the other hand, the first groove 123 causes the protective cover 14 to sink, thereby avoiding the explosion-proof valve 16 and allowing the explosion-proof valve 16 to fully contact the top cover 12, thus increasing the contact area.

[0036] The top cover 12 is provided with an explosion-proof hole 121 and a second groove 125 nested with the first groove 123. The edge of the explosion-proof valve 16 is accommodated in the second groove 125 to limit the position of the explosion-proof valve 16.

[0037] Please see Figures 1 to 3 , Figure 3 This is a schematic diagram of the cross-sectional structure of the protective cover 14 provided in this application.

[0038] The protective cover 14 includes a cover body 142 and a fixing part 144. The cover body 142 has an explosion-proof hole 121 through it. The cover body extends from one side of the explosion-proof hole 121 to the other side. The fixing part 144 surrounds the edge of the cover body 142 and is housed in the first groove 123. The explosion-proof valve 16 presses against the fixing part 144.

[0039] A vent 146 is provided on the side wall of the cover 142, extending beyond the top cover 12 to ensure airflow. After the explosion-proof valve 16 is secured, its sealing performance needs to be tested by evacuating the gas inside the housing 30. During this process, the cover 142 must be kept ventilated to ensure the test can proceed smoothly. Furthermore, the vent on the side wall of the cover 142 effectively prevents electrolyte overflow from contaminating the explosion-proof valve 16 when electrolyte is injected into the individual battery 100.

[0040] The number of vent holes 146 can be one, two, three, etc. The vent holes 146 can be distributed in the part of the protective cover 14 away from the injection hole.

[0041] The diameter of the vent 146 ranges from 0.03 mm to 1 mm, for example, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.08 mm, 0.09 mm, 1 mm, etc. Within this range, the vent 146 allows air to pass through but isolates the electrolyte.

[0042] The shape of the through hole is not limited to a circle; it can also be an oval, square, triangular, etc.

[0043] Please see Figure 4 and Figure 5 , Figure 4 This is a structural schematic diagram of the explosion-proof valve 16 provided in this application. Figure 5 This application provides Figure 4 A schematic diagram of the cross-sectional structure of region B in the middle.

[0044] The explosion-proof valve 16 of this application includes a connecting part 162 and a bursting part 164. The connecting part 162 surrounds the edge of the bursting part 164. The connecting part 162 is connected to the top cover 12 and a protective cover 14 is pressed on it. The connection method can be welding. The connecting part 162 is used to fix the explosion-proof valve 16. A groove 166 is provided on one side of the bursting part 164. The groove 166 is provided on the side of the bursting part 164 away from the inside of the housing 30 to prevent the electrolyte inside the housing 30 from corroding the groove 166.

[0045] The notch 166 includes a first blast mark 161 and a second blast mark 163, both of which are arc-shaped. The first blast mark 161 and the second blast mark 163 are symmetrical about the center of the blasting section 164 and are spaced apart from each other. The first blast mark 161 and the second blast mark 163 are used to break under a preset pressure. When the preset pressure is exceeded within the housing 30, the blasting section 164 will separate from the connecting portion 162 at the first blast mark 161 and the second blast mark 163, thereby forming an opening to release the pressure. On the one hand, the first blast mark 161 and the second blast mark 163 are spaced apart from each other, so when the blasting part 164 breaks at the first blast mark 161 and the second blast mark 163, the blasting part 164 will not fly out as a whole and cause a secondary accident; on the other hand, the first blast mark 161 and the second blast mark 163 are symmetrical about the center of the blasting part 164, so that the first blast mark 161 and the second blast mark 163 are always subjected to balanced internal pressure during the life cycle of the single battery 100, so that the explosion-proof valve 16 will not experience performance degradation under long-term stress.

[0046] The thickness of the connecting portion 162 includes 0.1 mm to 1.5 mm, such as 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, etc.

[0047] The notch 166 also includes a third burst mark 165, which is connected to the first burst mark 161 and the second burst mark 163, respectively. The third burst mark 165 is symmetrical about the center of the bursting part 164. When the preset pressure is exceeded inside the housing 30, the bursting part 164 will separate from the connecting part 162 at the first burst mark 161 and the second burst mark 163, and at the same time, the third burst mark 165 will break, thereby dividing the bursting part 164 into two independent parts to further increase the opening for releasing pressure.

[0048] The notch 166 also includes a first connecting notch 167 and a second connecting notch 169. The two ends of the first connecting notch 167 are respectively connected to one end of the first blasting notch 161 and the second blasting notch 163, and the two ends of the second connecting notch 169 are respectively connected to the other ends of the first blasting notch 161 and the second blasting notch 163. Firstly, the first connecting notch 167 and the second connecting notch 169 will not break when the pressure exceeds a preset value within the housing 30. The first connecting notch 167 and the second connecting notch 169 serve as a guide after the blasting part 164 breaks at the first blasting notch 161 and the second blasting notch 163, facilitating the smooth opening of the blasting part 164. The first connecting notch 167 and the second connecting notch 169 are symmetrical about the center of the blasting part 164.

[0049] The first connection mark 167 and the second connection mark 169 are symmetrical about the center of the rupture section 164. During the life cycle of the single cell 100, the first connection mark 167 and the second connection mark 169 are always subjected to balanced internal pressure, so that the explosion-proof valve 16 will not experience performance degradation under long-term stress.

[0050] Optionally, the depths of the first connection mark 167 and the second connection mark 169 are both less than the depths of the first blast mark 161 and the second blast mark 163, thereby ensuring that the first connection mark 167 and the second connection mark 169 do not break when the first blast mark 161 and the second blast mark 163 break. Of course, the first connection mark 167 and the second connection mark 169 can also be locally reinforced, for example, by increasing the hardness of the local stress or using a harder material locally.

[0051] In an optional embodiment, the first blast mark 161 and the second blast mark 163 have the same depth, thereby ensuring that the first blast mark 161 and the second blast mark 163 can break simultaneously; the first connection mark 167 and the second connection mark 169 have the same depth.

[0052] The depth of the first blast mark 161 ranges from 0.06 mm to 0.2 mm, for example, 0.06 mm, 0.08 mm, 0.10 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, etc.

[0053] The depth of the second blast mark 163 ranges from 0.06 mm to 0.2 mm, for example, 0.06 mm, 0.08 mm, 0.10 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, etc.

[0054] The depth of the first blast mark 161 is greater than the depth of the first connecting mark 167. The ratio of the depth of the first blast mark 161 to the depth of the first connecting mark 167 includes 1.2 to 3, for example, 1.2, 1.5, 2, 2.5, 3, etc. Within this range, the strength of the first connecting mark 167 is sufficient to prevent breakage when the explosion-proof valve 16 is activated, and it can also ensure that the first blast mark 161 and the second blast mark 163, after breakage, play a guiding role, facilitating the smooth opening of the blasting section 164 to its maximum state.

[0055] The depth of the second blast mark 163 is greater than the depth of the second connecting mark 169. The ratio of the depth of the second blast mark 163 to the depth of the second connecting mark 169 includes 1.2 to 3, for example, 1.2, 1.5, 2, 2.5, 3, etc. Within this range, the strength of the second connecting mark 169 is sufficient to prevent breakage when the explosion-proof valve 16 is activated, and it also ensures that after the first blast mark 161 and the second blast mark 163 break, they act as guides, facilitating the smooth opening of the blasting section 164 to its maximum state.

[0056] Please see Figure 6 , Figure 6 This is a top view of the explosion-proof valve 16 provided in this application.

[0057] The blasting section 164 is racetrack-shaped, consisting of two semicircles distributed at opposite ends of a rectangle. When the first blast mark 161 and the second blast mark 163 are respectively located in the width direction of the blasting section 164, the first connecting mark 167 and the second connecting mark 169 are respectively located in the length direction of the blasting section 164 (e.g., ...). Figure 6 (As shown); when the first blast mark 161 and the second blast mark 163 are respectively in the length direction of the blasting part 164, the first connecting mark 167 and the second connecting mark 169 are respectively in the width direction of the blasting part 164.

[0058] The length L1 of the first connecting mark 167 is shorter than the length L2 of the straight side of the blasting part 164. Specifically, the ratio of the length L1 of the first connecting mark 167 to the length L2 of the straight side of the blasting part 164 includes 0.2 to 0.4, for example, 0.2, 0.3, 0.4.

[0059] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural transformations made based on the content of the specification and drawings of this application under the concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A single-cell battery, characterized in that, The single battery includes: a cell, a casing, and a top cover assembly, wherein the cell is assembled in the casing, and the top cover assembly covers the casing; The top cover assembly includes: a top cover, a protective cover, and an explosion-proof valve arranged in sequence. The explosion-proof valve is connected to one side of the top cover and presses the protective cover in place. The top cover has an explosion-proof hole, and the protective cover passes through the explosion-proof hole to the other side of the top cover. The top cover is provided with the explosion-proof hole and has a first groove. The first groove is located on the side of the top cover facing the battery cell. The edge of the protective cover is accommodated in the first groove, and the explosion-proof valve is pressed against the edge of the protective cover. The protective cover includes a cover body and a fixing part. The cover body has the explosion-proof hole through it. The fixing part surrounds the edge of the cover body and is housed in the first groove. The explosion-proof valve presses against the fixing part. The explosion-proof valve is welded to the top cover to seal the explosion-proof hole; The top cover is provided with an explosion-proof hole and a second groove that is nested with the first groove, and the edge of the explosion-proof valve is accommodated in the second groove; After the explosion-proof valve is connected to the top cover, a fixed protective cover is pressed on it. The protective cover is made of plastic.

2. The single-cell battery according to claim 1, characterized in that, The side wall of the cover is provided with ventilation holes, which extend beyond the top cover.

3. The single-cell battery according to claim 1, characterized in that, The explosion-proof valve includes a connecting part and a bursting part. The connecting part is arranged around the edge of the bursting part. The connecting part is connected to one side of the top cover and presses and fixes the protective cover. The bursting part has a groove on the side facing the explosion-proof valve. The scoring includes a first blast mark and a second blast mark, both of which are arc-shaped. The first blast mark and the second blast mark are symmetrical about the center of the blasting part and are spaced apart from each other. The first blast mark and the second blast mark are used to break under a preset pressure.

4. The single-cell battery according to claim 3, characterized in that, The notch also includes a third blast mark, which is connected to the first blast mark and the second blast mark respectively, and the third blast mark is symmetrical about the center of the blasting part.

5. The single-cell battery according to claim 3, characterized in that, The engraving also includes a first connecting mark and a second connecting mark. The two ends of the first connecting mark are respectively connected to one end of the first blast mark and the second blast mark. The two ends of the second connecting mark are respectively connected to the other end of the first blast mark and the second blast mark. The first connecting mark and the second connecting mark are symmetrical about the center of the blasting part.

6. The single-cell battery according to claim 5, characterized in that, The first blast mark and the second blast mark have the same depth, and the first connection mark and the second connection mark have the same depth.

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