Inflatable liquid injection port sealing device and lithium ion battery

Abstract

The utility model belongs to the technical field of formation equipment, and particularly relates to an inflatable liquid injection port sealing device and a lithium ion battery. According to the technical scheme, the inflatable liquid injection port sealing device comprises a sealing column, the sealing column is inserted into a liquid injection port of a battery, an inflatable ring is arranged in the sealing column, the inflatable ring expands outwards to form a convex ring after being inflated, and the convex ring seals the liquid injection port of the battery. The utility model provides the inflatable liquid injection port sealing device which can be repeatedly used and is reliable in sealing, and the lithium ion battery using the inflatable liquid injection port sealing device.

Description

Technical Field

[0001] The utility model belongs to the technical field of forming equipment, and particularly relates to an inflatable liquid injection port sealing device and a lithium-ion battery. Background Technique

[0002] Lithium-ion batteries are currently the most advanced commercial secondary batteries in the world. They have the advantages of high energy density, long cycle life, low self-discharge rate, and no memory effect, and are widely used in various fields such as portable electronic devices and electric vehicles. In the production process of lithium-ion batteries, liquid injection and forming are two key processes. Among them, liquid injection refers to injecting electrolyte into the battery, and forming refers to making the active substances inside the battery undergo an electrochemical reaction through certain current and voltage conditions to activate the battery. During the high-temperature infiltration process after liquid injection and before forming, a forming nail needs to be inserted into the battery liquid injection port to prevent the volatilization of the electrolyte and the entry of external moisture, so as to ensure the electrical performance and safety performance of the battery.

[0003] At present, the forming nails used in lithium-ion batteries are all disposable forming nails. The main function of this kind of forming nail is to physically block the battery liquid injection port during the electrolyte infiltration process to prevent the volatilization of the electrolyte and the entry of external moisture. However, when using this kind of forming nail, the insertion and extraction of the nail need to be carried out under conditions with relatively large resistance, which will reduce the sealing performance of the forming nail. To ensure the quality of the battery core, usually the current forming nails are used only once.

[0004] Although disposable forming nails can meet the sealing requirements, they have some problems. First of all, the use of disposable forming nails is not environmentally friendly because they will be discarded after use, resulting in waste of resources and environmental pollution. Secondly, the use of disposable forming nails also increases the manufacturing cost of the battery because new forming nails are required for each liquid injection and forming, which undoubtedly increases the production cost of the enterprise. Finally, the use of disposable forming nails will also affect the quality of the battery because the sealing performance of the forming nail may be affected during the insertion and extraction process, thus affecting the performance of the battery.

[0005] In the prior art, a battery cell formation sealing member, a battery cell formation device, and a battery cell formation method are provided. The battery cell formation sealing member includes a support member and an elastic body. The elastic body is a hollow structure with a cavity formed therein. An inflation port and a mounting port are formed on one surface of the elastic body. The cavity is communicated with the inflation port. A communication port penetrating through the support member is formed on the support member. Among them, the elastic body expands after being inflated, can closely fit with the battery cell housing, realizes the sealing of the interior of the battery cell, can effectively avoid the deformation of the battery cell housing during use, and can perform operations such as vacuum pumping, gas replacement, and liquid injection through the communication port, effectively reducing processes such as cleaning of the battery liquid injection port, reducing manual operations, simplifying the battery production process flow, improving the production efficiency of the battery, reducing the manufacturing cost, improving the production quality of the battery, and reducing carbon emissions during the production process.

[0006] Among them, the support member and the elastic body constitute the battery cell formation sealing member. A seal is formed between the inflated elastic body of the battery cell formation sealing member and the battery cell housing, and the communication port for injecting liquid into the battery cell is arranged on the support member. Thus, it can be inferred that the battery cell formation sealing member is equivalent to a relatively large cover plate of the battery cell, and the range that needs to be sealed between it and the battery cell housing is relatively large. Sealing by inflating the elastic body makes it difficult to ensure reliable sealing at each contact position. Summary of the Invention

[0007] In order to solve the above problems existing in the prior art, the purpose of the present invention is to provide a new inflatable liquid injection port sealing device that can be reused and has reliable sealing, and a lithium-ion battery using the inflatable liquid injection port sealing device.

[0008] The technical solution adopted by the present invention is as follows:

[0009] An inflatable liquid injection port sealing device includes a sealing column for inserting into the liquid injection port of a battery. The sealing column has a hollow inner cavity, so that a part of the sealing column expands outward into a convex ring-shaped air expansion ring after being inflated to seal the liquid injection port of the battery.

[0010] During high-temperature infiltration and high-temperature aging of the battery, the formation nail is inserted into the battery liquid injection port, and then dry gas is injected into the air expansion ring to make the air expansion ring expand to completely seal the battery liquid injection port. When the nail needs to be pulled out, the air expansion ring is deflated. After deflation, the air expansion ring shrinks, and then the formation nail is pulled out.

[0011] The present invention adopts a reusable inflatable liquid injection port sealing device, which greatly reduces the waste of resources and environmental pollution compared with disposable formation nails, and is more environmentally friendly.

[0012] Since the formation nail of the utility model can be reused, it is not necessary to replace a new formation nail each time the battery is injected and the formation is completed, thereby significantly reducing the manufacturing cost of the battery and being beneficial to improving the economic benefits of the enterprise.

[0013] The formation nail of the utility model is sealed and unsealed by means of inflation and deflation, thus avoiding the influence on the sealing property of the formation nail during the traditional nail insertion and nail extraction process, thereby improving the performance and service life of the battery.

[0014] The formation nail of the utility model is inserted into the liquid injection port of the battery, and sealing is achieved by inflation. Compared with sealing the battery cell shell and the cover plate by inflation, the sealing area of ​​the utility model is smaller, and the inflation ring can ensure reliable sealing at various circumferential positions.

[0015] As a preferred embodiment of the utility model, at the position of the inflation ring, the wall thickness of the sealing column is thinned to form a thinned area of ​​annular cross-section, and after the sealing column is inflated, the thinned area expands outward to form the inflation ring. Since the inflation ring is formed by the thinned area in the sealing column, it is easier for the inflation ring to expand and bulge outward after inflation, thereby improving the sealing effect. If only a cavity is set in the sealing column and a seal is formed when the cavity is inflated, the bulge of the inflation ring is not obvious, and the inflation ring and other areas of the sealing column have a smoother transition, resulting in a smaller contact area with the injection port and a more prone to air leakage.

[0016] As a preferred solution of the utility model, one end of the sealing column is configured as a guide column with gradually decreasing external dimensions; the guide column is in the shape of a truncated cone. The main function of the guide column is to guide the formation nail when it is inserted into the injection port, so as to facilitate the insertion of the formation nail into the injection port.

[0017] As a preferred solution of the utility model, a handle is provided at one end of the sealing column; a guide column is provided at the other end of the sealing column, and the guide column, the sealing column and the handle are an integrated structure.

[0018] As a preferred solution of the utility model, an internal sealed chamber is provided in the handle, and the internal sealed chamber is communicated with the inflatable ring. Dry gas is introduced into or discharged from the inflatable ring through the internal sealed chamber, and since the handle is arranged outside the liquid injection port, the operation of inflation or exhaust is convenient.

[0019] As a preferred solution of the utility model, an air valve for air intake and air release is arranged in the handle, and the internal sealed chamber is surrounded by the handle and the air valve.

[0020] As a preferred embodiment of the utility model, the air valve includes an air inlet valve body, which is arranged in the handle, a sealing ring is arranged in the air inlet valve body, and an air port connecting the outside world and the internal sealed chamber respectively is arranged in the sealing ring, and the air port is used for air intake and air discharge.

[0021] As a preferred embodiment of the present utility model, the intake valve body and the handle are of an integral structure, or the intake valve body is bonded to the handle.

[0022] As a preferred embodiment of the present utility model, an intake rod is sleeved inside the sealing ring, the intake rod passes through the air port, and a sealing block for opening or sealing the air port is arranged at one end of the intake rod extending into the internal sealing chamber.

[0023] As a preferred embodiment of the present utility model, a spring pressing block is fixed on the intake rod, and a spring is arranged between the spring pressing block and the sealing ring.

[0024] When air intake or air release is required, the intake rod is pushed downward. Under the action of the spring pressing block, the spring is compressed, and the sealing block moves downward accordingly, and the air valve opens to allow gas to pass through or be released. When the air intake or air release is completed, the downward force applied to the intake rod is released, and the compressed spring rebounds, pushing the spring pressing block upward, and then driving the sealing block upward to block the air port to form a seal.

[0025] As a preferred embodiment of the present utility model, the intake rod, the spring pressing block and the sealing block are of an integral structure.

[0026] As a preferred embodiment of the present utility model, an upper limiting step for limiting the spring pressing block and a lower limiting step for limiting the spring are arranged on the sealing ring. The upper limiting step, the spring pressing block, the spring and the lower limiting step are arranged in sequence, and the spring is sleeved on the intake rod.

[0027] A lithium-ion battery includes a battery cell and the above-mentioned novel inflatable liquid injection port sealing device; wherein, the battery cell includes a battery cell housing, a liquid injection port is arranged on the battery cell housing, and the diameter of the sealing column (2) is larger than the inner diameter of the liquid injection port of the battery.

[0028] The beneficial effects of the present utility model are as follows:

[0029] 1. The present utility model adopts a reusable inflatable liquid injection port sealing device, which greatly reduces the waste of resources and environmental pollution compared with disposable formation nails, and is more environmentally friendly.

[0030] 2. Since the formation nails of the present utility model can be reused and there is no need to replace new formation nails every time for liquid injection and formation, the manufacturing cost of the battery is significantly reduced, which is beneficial to improving the economic benefits of the enterprise.

[0031] 3. The formation nails of the present utility model are sealed and unsealed by inflating and deflating, which avoids the influence on the sealing performance of the formation nails during the traditional process of inserting and pulling out nails, thereby improving the performance and service life of the battery.

[0032] 4. The formation nail of the utility model is inserted into the liquid injection port of the battery and is sealed by inflation. Compared with sealing the battery cell shell and the cover plate by inflation, the sealing area of ​​the utility model is smaller, and the inflation ring can ensure reliable sealing at all circumferential positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a cross-sectional view of the utility model before inflation;

[0034] Figure 2 It is a cross-sectional view of the gas valve;

[0035] Figure 3 It is a cross-sectional view of the utility model after inflation.

[0036] In the figure: 1-guide column; 2-sealing column; 3-expansion ring; 4-handle; 5-internal sealing chamber; 6-air valve; 7-intake valve body; 8-intake rod; 9-spring pressure block; 10-sealing ring; 11-spring; 12-air port; 13-sealing block. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0039] The forming nail is usually columnar in shape and is generally used to seal the liquid injection port of the cover of square hard shell battery cells (including blade type and half blade type battery cells).

[0040] Embodiment 1:

[0041] like Figures 1 to 3The longitudinal sectional view of the novel inflatable liquid injection port sealing device of this embodiment is shown, including a sealing column 2. The sealing column 2 is inserted into the liquid injection port of the battery. The sealing column 2 has a hollow inner cavity, and a part of the hollow inner cavity has a larger size so that the sealing column 2 forms an air inflation ring 3. Specifically, the part of the hollow inner cavity with a larger size expands outward into a convex ring after the air inflation ring 3 is inflated, and the convex ring seals the liquid injection port of the battery.

[0042] Among them, the part of the hollow inner cavity with a larger size makes the wall thickness of the sealing column 2 at this position thinner. The cross-section of the sealing column 2 at this position becomes a thinning area of an annular cross-section with a thinner wall thickness, and the thinning area forms the air inflation ring 3. Since the air inflation ring 3 is formed by the thinning area in the sealing column 2, the air inflation ring 3 is more likely to expand outward and bulge after inflation, thereby improving the sealing effect. If only a cavity is provided in the sealing column 2 and sealing is formed when the cavity is inflated, the bulge of the air inflation ring 3 is not obvious, and the air inflation ring 3 has a smoother transition with other areas of the sealing column 2, resulting in a smaller contact area with the liquid injection port and easier air leakage.

[0043] Furthermore, the diameter of the sealing column 2 is larger than the inner diameter of the liquid injection port of the battery. The diameter of the sealing column 2 is slightly larger than that of the liquid injection port, and a first-stage sealing effect is achieved through interference fit after being inserted into the liquid injection port.

[0044] To facilitate the insertion of the sealing column 2, one end of the sealing column 2 inserted into the liquid injection port is provided with a guide column 1 with a gradually decreasing external dimension. The main function of the guide column 1 is to guide during the insertion into the liquid injection port and facilitate the insertion into the liquid injection port. Among them, the shape of the guide column 1 is a frustum of a cone.

[0045] The end of the sealing column 2 far from the liquid injection port is set to have a handle 4 with a larger external dimension. An internal sealing chamber 5 is provided in the handle 4, and the internal sealing chamber 5 is communicated with the air inflation ring 3. Dry gas is introduced into or discharged from the air inflation ring 3 through the internal sealing chamber 5. Since the handle 4 is arranged outside the liquid injection port, the operation of inflation or exhaust is facilitated.

[0046] Among them, the guide column 1, the sealing column 2 and the handle 4 are of an integral structure.

[0047] The diameter of the sealing column 2 of the present utility model is slightly larger than the inner diameter of the cell liquid injection port, and sealing is performed through a relatively light extrusion force. This design enables an effective first-stage sealing to be formed after being inserted into the cell liquid injection port. The air inflation ring 3 is a thinning layer in the sealing column. When the sealing column 2 enters the liquid injection port, dry gas is injected into the sealing chamber. Due to the action of pressure, the air inflation ring 3 expands to completely seal the battery liquid injection port. This design enables a second-stage sealing to be formed after injecting dry gas, further improving the sealing performance.

[0048] When the nail needs to be pulled out, first deflate the sealing chamber. After deflation, the inflatable ring 3 shrinks, and then it can be pulled out. The sealing performance during the nail-pulling process is basically not affected. This design enables convenient insertion and extraction of the nail when replacement or maintenance is required, without affecting its sealing performance.

[0049] When the battery is subjected to high-temperature soaking and high-temperature aging, it will be inserted into the battery liquid injection port, and then dry gas is injected into the sealing chamber to expand the inflatable ring 3, achieving complete sealing of the battery liquid injection port. When the nail needs to be pulled out, first deflate the sealing chamber through the air valve 6. After deflation, the inflatable ring 3 shrinks, and then it can be pulled out. This usage method basically has no impact on the sealing performance.

[0050] The utility model adopts a reusable inflatable sealing device for the liquid injection port, which significantly reduces waste of resources and environmental pollution compared with disposable ones, and is more environmentally friendly.

[0051] Due to the fact that the utility model can be reused and there is no need to replace a new one every time during liquid injection and formation, the manufacturing cost of the battery is significantly reduced, which is beneficial to improving the economic benefits of the enterprise.

[0052] The utility model seals and unseals through inflation and deflation, avoiding the impact on sealing performance during the traditional nail insertion and extraction processes, thereby improving the performance and service life of the battery.

[0053] The utility model is inserted into the liquid injection port of the battery and achieves sealing through inflation. Compared with sealing the battery cell housing and the cover plate through inflation, the sealing area of the utility model is smaller, and the inflatable ring 3 can ensure reliable sealing at all circumferential positions.

[0054] Embodiment 2:

[0055] On the basis of Embodiment 1, in order to facilitate inflation and exhaust, an air valve 6 for intake and deflation is arranged inside the handle 4, and the internal sealing chamber 5 is surrounded by the handle 4 and the air valve 6.

[0056] Specifically, as Figure 2 shown, the air valve 6 includes an intake valve body 7. The intake valve body 7 is arranged inside the handle 4. A sealing ring 10 is arranged inside the intake valve body 7. Air ports 12 communicating with the outside and the internal sealing chamber 5 are arranged inside the sealing ring 10, and the air ports 12 are used for intake and deflation.

[0057] The intake valve body 7 and the handle 4 are of an integral structure, or the intake valve body 7 is bonded to the handle 4.

[0058] Furthermore, an intake rod 8 is sleeved inside the sealing ring 10. The intake rod 8 passes through the air port 12, and a sealing block 13 for opening or sealing the air port 12 is arranged at one end of the intake rod 8 extending into the internal sealing chamber 5. A spring pressing block 9 is fixed on the intake rod 8, and a spring 11 is arranged between the spring pressing block 9 and the sealing ring 10.

[0059] When air intake or air release is required, the intake rod 8 is pushed downward. Under the action of the spring pressing block 9, the spring 11 is compressed, and the sealing block 13 moves downward accordingly, and the air valve 6 is opened to allow gas to pass through or be released. When the air intake or air release is completed, the downward force applied to the intake rod 8 is released, and the compressed spring 11 rebounds, pushing the spring pressing block 9 upward, and then driving the sealing block 13 upward to block the air port 12 to form a seal.

[0060] The intake rod 8, the spring pressing block 9 and the sealing block 13 are of an integral structure.

[0061] Wherein, an upper limit step for limiting the spring pressing block 9 and a lower limit step for limiting the spring 11 are arranged on the sealing ring 10. The upper limit step, the spring pressing block 9, the spring 11 and the lower limit step are arranged in sequence, and the spring 11 is sleeved on the intake rod 8.

[0062] The diameter of the sealing column 2 of the present utility model is slightly larger than the inner diameter of the battery cell liquid injection port, and is sealed by a relatively light extrusion force. This design enables an effective first seal to be formed after inserting into the battery cell liquid injection port. The air expansion ring 3 is a reduced-thickness layer in the sealing column. When the sealing column 2 enters the liquid injection port, dry gas is injected into the sealing chamber through the air valve 6. Due to the action of pressure, the air expansion ring 3 expands to completely seal the battery liquid injection port. This design enables a second seal to be formed after injecting the dry gas, further improving the sealing performance.

[0063] When the nail needs to be pulled out, first, the sealing chamber is deflated through the air valve 6. After deflation, the air expansion ring 3 contracts, and then it can be pulled out. The sealing performance during the nail pulling process is basically not affected. This design enables convenient insertion and pulling out of the nail when replacement or maintenance is required, without affecting its sealing performance.

[0064] When the battery is subjected to high-temperature infiltration and high-temperature aging, it is inserted into the battery cell liquid injection port, and then dry gas is injected into the sealing chamber through the air valve 6 to make the air expansion ring 3 expand to completely seal the battery liquid injection port. When the nail needs to be pulled out, first, the sealing chamber is deflated through the air valve 6. After deflation, the air expansion ring 3 contracts, and then it can be pulled out. This usage method basically does not have any impact on the sealing performance.

[0065] Embodiment 3:

[0066] On the basis of Embodiment 2, this embodiment provides a lithium-ion battery, which includes a battery cell and the novel inflatable liquid injection port sealing device in Embodiment 2. The battery cell includes a battery cell housing, which is an integral structure, and a liquid injection port is provided on the battery cell housing.

[0067] The present utility model is not limited to the above optional embodiments. Any person can obtain other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in its shape or structure, as long as the technical solutions fall within the scope defined by the claims of the present utility model, they shall fall within the protection scope of the present utility model.

Claims

1. An inflatable liquid injection port sealing device, characterized in that: The invention comprises a sealing column (2) for inserting into the liquid injection port of the battery, wherein the sealing column (2) has a hollow inner cavity, so that a part of the sealing column (2) expands outwards to form a convex ring-shaped inflation ring (3) after being inflated, thereby sealing the liquid injection port of the battery.

2. The inflatable liquid injection port sealing device according to claim 1, characterized in that: At the position of the inflation ring (3), the wall thickness of the sealing column (2) is thinned to form a thinned area with an annular cross section. After the sealing column (2) is inflated, the thinned area expands outwards to form the inflation ring (3).

3. The inflatable liquid injection port sealing device according to claim 1, characterized in that: One end of the sealing column (2) is configured as a guide column (1) with gradually decreasing external dimensions; the guide column (1) is in the shape of a truncated cone.

4. The inflatable liquid injection port sealing device according to claim 1, characterized in that: A handle (4) is provided at one end of the sealing column (2); a guide column (1) is provided at the other end of the sealing column (2); the guide column (1), the sealing column (2) and the handle (4) are an integrated structure.

5. The inflatable liquid injection port sealing device according to claim 4, characterized in that: An internal sealed chamber (5) is provided in the handle (4), and the internal sealed chamber (5) is communicated with the inflatable ring (3).

6. The inflatable liquid injection port sealing device according to claim 5, characterized in that: An air valve (6) for air intake and air discharge is arranged inside the handle (4), and the internal sealed chamber (5) is surrounded by the handle (4) and the air valve (6).

7. The inflatable liquid injection port sealing device according to claim 6, characterized in that: The air valve (6) comprises an air inlet valve body (7), wherein the air inlet valve body (7) is arranged in the handle (4), wherein a sealing ring (10) is arranged in the air inlet valve body (7), wherein an air port (12) which is connected to the outside and the internal sealing chamber (5) is arranged in the sealing ring (10), and wherein the air port (12) is used for air intake and air discharge.

8. The inflatable liquid injection port sealing device according to claim 7, characterized in that: The air intake valve body (7) and the handle (4) are an integral structure, or the air intake valve body (7) and the handle (4) are bonded together.

9. The inflatable liquid injection port sealing device according to claim 7, characterized in that: An air intake rod (8) is sleeved inside the sealing ring (10), and the air intake rod (8) passes through the air port (12). One end of the air intake rod (8) extending into the internal sealing chamber (5) is provided with a sealing block (13) for opening or sealing the air port (12).

10. The inflatable liquid injection port sealing device according to claim 9, characterized in that: A spring pressure block (9) is fixed on the air intake rod (8), and a spring (11) is arranged between the spring pressure block (9) and the sealing ring (10).

11. The inflatable liquid injection port sealing device according to claim 10, characterized in that: The air intake rod (8), the spring pressure block (9) and the sealing block (13) are an integrated structure.

12. The inflatable liquid injection port sealing device according to claim 10, characterized in that: The sealing ring (10) is provided with an upper limit step for limiting the position of the spring pressure block (9) and a lower limit step for limiting the position of the spring (11).

13. A lithium ion battery, characterized in that: It comprises a battery cell and an inflatable liquid injection port sealing device as claimed in any one of claims 1 to 12, wherein the battery cell comprises a battery cell shell, a liquid injection port is arranged on the battery cell shell, and the diameter of the sealing column (2) is larger than the inner diameter of the liquid injection port of the battery.

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