Battery cell, secondary battery, and battery pack

Abstract

This application relates to the field of battery pack technology, and more particularly to a cell housing, a secondary battery, and a battery pack. The cell housing includes: a top cover with a liquid inlet for adding repair material; a lower housing that, together with the top cover, forms a receiving cavity for accommodating the cell; and a liquid injection structure disposed within the receiving cavity, the liquid injection structure including a flow channel for fluid circulation, at least a portion of which has a flow-blocking portion; the liquid injection structure has an inlet and an outlet, the inlet communicating with the liquid inlet and the outlet communicating with the receiving cavity. When repair material is added to the cell housing through the liquid inlet, the repair material must flow through the liquid injection structure to enter the receiving cavity. Because at least a portion of the liquid injection structure has a flow-blocking portion, the liquid injection structure can buffer the flow of the repair material, preventing the repair material from flowing violently within the cell housing, thereby preventing the repair material from impacting and damaging the cell.

Description

Technical Field

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

[0002] Existing rechargeable batteries have a limited cycle life. Towards the end of the cycle, the amount of active material inside the battery decreases significantly, and the performance of the electrolyte also deteriorates severely. These factors lead to a substantial decline in the battery's performance.

[0003] Injecting lithium replenisher and fresh electrolyte into a secondary battery is an effective method to restore battery performance. During the repair process, technicians add the lithium replenisher and electrolyte directly from the top of the secondary battery. The violently flowing electrolyte impacts the fragile electrodes, further exacerbating the damage and potentially causing permanent damage to battery performance. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a cell housing, a secondary battery, and a battery pack.

[0005] In a first aspect, this application provides a battery cell housing. The battery cell housing described in this application includes:

[0006] A top cover, the top cover having a liquid inlet for adding repair material;

[0007] The lower housing and the top cover form a receiving cavity for accommodating the battery cell;

[0008] The liquid injection structure is disposed in the receiving cavity. The liquid injection structure includes a flow channel for fluid flow, and at least a portion of the flow channel of the liquid injection structure is provided with a flow obstruction part. The liquid injection structure has a liquid inlet and a liquid outlet, the liquid inlet is connected to the liquid replenishment port, and the liquid outlet is connected to the receiving cavity.

[0009] Optionally, the lower housing is formed by a straight portion and a bent portion, with the bent portion connecting adjacent straight portions, and the lower housing also includes a baffle.

[0010] The baffle is located in the receiving cavity and is fixedly connected to the bent portion, and the baffle and the bent portion surround the liquid injection structure;

[0011] The liquid injection structure has a first opening on the side facing the top cover, the first opening being used to form the liquid inlet; or, the baffle of the liquid injection structure has a second opening, the second opening being used to form the liquid inlet.

[0012] There is a gap between the liquid injection structure and the bottom wall of the lower housing, the gap being used to form the liquid outlet; or, the baffle of the liquid injection structure has a third opening, the third opening being used to form the liquid outlet.

[0013] Optionally, the surface of the bend in the injection structure is provided with the flow-blocking part, and / or the surface of the baffle in the injection structure is provided with the flow-blocking part.

[0014] Optionally, the injection structure is disposed within the receiving cavity, and at least a portion of the injection structure is a curved section, which forms the flow-blocking part;

[0015] The curved pipe section includes a plurality of sequentially connected bent pipes, at least a portion of which bend in a first direction, and at least another portion of which bend in a second direction, wherein the first direction and the second direction are different.

[0016] Optionally, the lower housing has a buffer structure, which is disposed toward the liquid outlet so that the fluid flowing out of the liquid outlet is dispersed when it passes through the buffer structure.

[0017] Optionally, the battery cell housing includes a porous adsorption structure; the porous adsorption structure is disposed within the liquid injection structure.

[0018] Optionally, the porous adsorption structure is located at the end section of the injection structure near the replenishment port, and the flow-blocking part is located on the side of the porous adsorption structure opposite to the replenishment port, and the flow-blocking part is used to support the porous adsorption structure.

[0019] Optionally, the cell housing includes a semi-permeable membrane for gas to pass through;

[0020] The baffle includes a first baffle and a second baffle. The first side of the first baffle and the second baffle serve as the inner wall of the liquid injection structure, and the second side serves as the outer wall of the liquid injection structure. An opening is provided between the first baffle and the second baffle to form the liquid outlet. One end of the semipermeable membrane is rotatably connected to the first baffle. When the semipermeable membrane closes the liquid outlet, the other end of the semipermeable membrane is located on the second side of the second baffle, and the other end of the semipermeable membrane at least partially covers the second baffle.

[0021] Secondly, this application also provides a secondary battery, which includes any of the cell housings and cells as described in the first aspect, wherein the cell is disposed within the cell housing.

[0022] Thirdly, this application also provides a battery pack, which includes a secondary battery as described in the second aspect.

[0023] In some implementations of this application, the battery cell housing includes a top cover and a lower cover, which together form a cavity for accommodating the battery cell. A liquid injection structure is provided within the cavity, located at a corner of the lower cover, and at least a portion of the liquid injection structure has a flow-blocking portion. The inlet of the liquid injection channel communicates with the replenishment port of the top cover, and the outlet of the liquid injection channel communicates with the cavity.

[0024] When adding repair material into the cell housing through the replenishment port, the repair material needs to flow through the injection structure to enter the receiving cavity. Since at least part of the injection structure has a flow-blocking section, the injection structure can buffer the flow of the repair material to prevent it from flowing violently within the cell housing, thereby preventing the repair material from impacting and damaging the cell.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0027] Figure 1 This is a schematic diagram of the structure of the battery cell housing described in this application;

[0028] Figure 2 yes Figure 1 Top view;

[0029] Figure 3 yes Figure 1 A cross-sectional schematic diagram;

[0030] Figure 4 yes Figure 3 A schematic diagram of the structure when the semipermeable membrane is open;

[0031] Figure 5 This is a schematic diagram of the structure of another battery cell housing described in this application;

[0032] Figure 6 This is a schematic diagram of the liquid outlet and buffer structure;

[0033] Reference numerals: 1. Top cover; 11. Liquid inlet; 2. Lower shell; 2a. Straight section; 2b. Bending section; 21. Baffle; 211. First baffle; 212. Second baffle; 22. Buffer structure; 3. Receiving cavity; 4. Liquid injection structure; 4a. Liquid inlet; 4b. Liquid outlet; 41. Flow blocking section; 5. Porous adsorption structure; 6. Semi-permeable membrane; 7. Sealing cap; 100. Battery cell. Detailed Implementation

[0034] The embodiments of this utility model will now be described in detail. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0035] Existing rechargeable batteries have a limited cycle life. Towards the end of the cycle, the amount of active material inside the battery decreases significantly, and the performance of the electrolyte also deteriorates severely. These factors lead to a substantial performance degradation in the rechargeable battery. To maintain the energy density of the rechargeable battery at the end of the cycle, engineers have proposed a repair technique involving lithium replenishment to restore the battery.

[0036] Specifically, for secondary batteries that have reached the end of their cycle, technicians will inject lithium replenisher and fresh electrolyte into the battery to replenish the consumed lithium ions and electrolyte. To facilitate the addition of lithium replenisher and fresh electrolyte, technicians will create a replenishment port on the top of the secondary battery. During the repair process, technicians will add lithium replenisher and electrolyte directly through this replenishment port on the top of the secondary battery.

[0037] Under the influence of gravity, the electrolyte will flow violently within the secondary battery, impacting the fragile electrodes. This will further exacerbate the damage to the electrodes, ultimately causing permanent damage to the battery's performance.

[0038] To address the aforementioned issues, embodiments of this application provide a cell casing, a secondary battery, and a battery pack.

[0039] Firstly, this application provides a battery cell housing. (Reference) Figure 1 The battery cell housing described in this application specifically includes a top cover 1, a lower housing 2, and an electrolyte injection structure 4.

[0040] refer to Figure 1The top cover 1 is generally made of metal and has a replenishment port 11 for adding repair material. In the embodiments described in this application, the repair material can be either a lithium replenishing agent or fresh electrolyte, or a mixture of the two. The shape of the replenishment port 11 can be set according to actual needs. Typically, the replenishment port 11 penetrates the top cover 1 along its thickness direction, and the cross-sectional shape of the replenishment port 11 along the thickness direction of the top cover 1 can be a conventional geometric shape such as a circle, rectangle, triangle, or hexagon. For example, the replenishment port is a triangular hole with a side length of 0.5 cm and a depth of 3 mm. Of course, the cross-sectional shape of the replenishment port 11 can also be an irregular geometric shape. To ensure sealing, a sealing cap 7 can be provided on the replenishment port 11. The sealing cap 7 can specifically be a sheet welded to the sealing port, with a size of 12 mm × 12 mm and a thickness of 1 mm, made of metal or polymer material. A pull ring is provided on it. When it is necessary to add repair material into the cell casing, the sealing cap 7 can be opened using the pull ring to expose the fluid inlet 11. After adding the repair material, the new sealing cap 7 can be welded to the fluid inlet 11.

[0041] The lower housing 2 and the top cover 1 can be fixedly connected by means of adhesive bonding, welding, etc., to form a receiving cavity 3 for accommodating the battery cell 100. (Reference) Figure 2 Cell 100 is a structure formed by winding electrode sheets. (Reference) Figure 3 The liquid injection structure 4 is disposed within the receiving cavity 3 and has an inlet 4a and an outlet 4b. The inlet 4a is connected to the replenishment port 11 on the top cover 1. In the embodiment described in this application, the inlet 4a and the replenishment port 11 on the top cover 1 can be connected by welding, bonding, or jointing. The outlet 4b of the liquid injection structure 4 is connected to the receiving cavity 3.

[0042] refer to Figure 3 , Figure 4The injection structure 4 includes a flow channel for fluid flow, and at least a portion of the flow channel of the injection structure 4 has a flow-blocking portion 41. In other words, all flow channels of the injection structure 4 have flow-blocking portions 41, or a portion of the injection structure 4 has flow-blocking portions 41. In the embodiments described in this application, the flow-blocking portion 41 can be a protrusion located inside the injection structure 4, such as a plate-shaped protrusion, a columnar protrusion, etc. The flow-blocking portion 41 can also be a partially curved section of the injection structure 4. The flow-blocking portion 41 can provide resistance to the fluid in the flow channel of the injection structure 4 to slow down the flow of the fluid. Specifically, when the repair material is added into the cell housing, the repair material flows into the inlet 4a of the injection structure 4 through the replenishment port 11. When the repair material flows in the injection structure 4, the flow of the repair material is slowed down by the influence of the flow-blocking portion 41. In this way, when the repair material flows out from the outlet 4b of the injection structure 4, its flow is relatively gentle and it is not easy to cause impact on the cell 100 in the receiving cavity 3. This can prevent cell 100 from being damaged by the violent flow of repair material, and thus prevent the performance of the secondary battery formed by cell casing and cell 100 from being damaged.

[0043] In one embodiment, the liquid injection structure 4 is located at the corner of the lower housing 2, such as... Figure 2 As mentioned above, there is extra space at the corner of the battery cell casing, and the liquid injection structure 4 at the corner is unlikely to interfere with the installation of the battery cell.

[0044] refer to Figure 2 In the embodiments described in this application, for example, the lower shell 2 is formed by straight portions 2a and bent portions 2b, with a bent portion 2b connecting adjacent straight portions 2a. In other words, the lower shell 2 has a prismatic shape, specifically a triangular prism, a quadrangular prism, a pentagonal prism, etc. For example, when the lower shell 2 has a cubic shape, it includes four bent portions 2b and four straight portions 2a. The cross-sectional shape of the four bent portions 2b along the extending direction is L-shaped. Among the four straight portions 2a, two straight portions 2a are arranged relatively spaced apart, and the other two straight portions 2a are arranged relatively spaced apart along another orthogonal direction. The four bent portions 2b are respectively connected between two adjacent straight portions 2a to form a frame with a rectangular cross-section. The lower shell 2 also includes a bottom, which is located at the same end as the straight portions 2a and the bent portions 2b to form a shell structure with an opening. The top cover 1 is connected to the opening of the lower shell 2 to form a sealed receiving cavity 3.

[0045] refer to Figure 3 , Figure 4The lower housing 2 also includes a baffle 21. The baffle 21 is located inside the receiving cavity 3 and is fixedly connected to the bent portion 2b. The baffle 21 and the bent portion 2b form a liquid injection structure 4, and the space between the baffle 21 and the bent portion 2b is the flow channel of the liquid injection structure 4. The baffle 21 and the bent portion 2b can be fixedly connected by welding, bonding, or other methods. Specifically, when the lower housing 2 is the aforementioned cubic shape, the baffle 21 and the bent portion 2b can form a flow channel with a right-angled triangle cross-section. The two surfaces of the bent portion 2b facing the baffle 21 form the two legs of the right triangle, and the surface of the baffle 21 facing the bent portion 2b forms the hypotenuse of the right triangle. Since the battery cell 100 is generally cylindrical, when it is placed in the prismatic battery cell housing, there is a certain amount of unused space at the position of the bent portion 2b of the lower housing 2. The liquid injection structure 4 is formed by the baffle 21 and the bent portion 2b of the lower housing 2, which is equivalent to utilizing this unused space to set up the liquid injection structure 4. This reduces the impact of the liquid injection structure 4 on the battery cell 100 and makes the use of internal space in the battery cell housing more reasonable.

[0046] In one embodiment, the liquid injection structure has a first opening on the side facing the top cover 1, the first opening being used to form a liquid inlet 4a.

[0047] In another embodiment, the baffle 21 of the injection structure has a second opening for forming an inlet 4a. It is understood that the second opening can be made on the side of the baffle 21 near the top cover 1, and the second opening can be connected to the replenishment port 11.

[0048] In one embodiment, there is a gap between the liquid injection structure and the bottom wall of the lower housing 2, the gap being used to form the liquid outlet 4b. It is understood that the bottom wall of the lower housing 2 refers to the side of the battery housing facing the bottom of the battery cell.

[0049] In another embodiment, the baffle 21 of the injection structure has a third opening for forming an outlet 4b. It is understood that the third opening can be formed on the side of the baffle 21 near the bottom wall, and the third opening communicates with the receiving cavity 3.

[0050] refer to Figure 3 , Figure 4In some embodiments of this application, for example, the surface of the bend 2b in the injection structure 4 is provided with a flow-blocking portion 41, and / or the surface of the baffle 21 in the injection structure 4 is provided with a flow-blocking portion 41. Specifically, the flow-blocking portion 41 can be a plate-shaped protrusion, the extension direction of which is arranged along the extension direction of the flow channel in the injection structure 4. Alternatively, the flow-blocking portion 41 can also be a strip-shaped protrusion, the extension direction of which is orthogonal to the extension direction of the flow channel in the injection structure 4, and the cross-sectional shape of the strip-shaped protrusion along its own extension direction can be triangular, rectangular, semi-circular, etc. Alternatively, the flow-blocking portion 41 can also be a spherical, prism-shaped, pyramidal, conical, or other geometrically shaped protrusion. The flow-blocking portion 41 can be provided only on the surface of the bend 2b in the injection structure 4, or it can be provided on the surface of the baffle 21 in the injection structure 4, or it can be provided on the surfaces of both the bend 2b and the baffle 21 in the injection structure 4. When the flow-blocking part 41 is a protrusion, the number of protrusions can be set according to actual needs; the number can be one, two, three, four, or even more. The aforementioned protruding structure of the flow-blocking part 41 can change the flow direction of the flow channel within the injection structure 4, thus making the flow channel within the injection structure 4 more complex. After the repair material is injected into the injection structure 4, the repair material will continuously collide with the flow-blocking part 41 during its flow. Therefore, the flow-blocking part 41 can slow down the flow of the repair material, making the flow of the repair material more stable. Furthermore, the injection structure 4 has protrusions that serve as flow-blocking parts 41, and the position, number, and shape of the protrusions can be set according to actual needs. This allows the shape of the flow channel within the injection structure 4 to conform as closely as possible to actual needs. In other words, the aforementioned protrusions in the flow-blocking part 41 facilitate its flexible arrangement.

[0051] refer to Figure 5 In some embodiments of this application, for example, the injection structure 4 is disposed within the receiving cavity 3, and at least a portion of the injection structure 4 is a curved section, with the flow-blocking part 41 being the curved section of the injection structure 4. For example, the injection structure has a thickness of 0.5 mm and a bending radius of 3 mm. The injection structure 4 can be specifically bonded to the lower housing 2 or the battery cell 100 with structural adhesive, or a buffer pad made of polyester film or foam material can be provided between the injection structure 4 and the battery cell 100, which can both protect the battery cell 100 from friction and provide limiting support for the injection structure 4. Specifically, the curved section includes multiple sequentially connected bent tubes, wherein at least a portion of the bent tubes bend in a first direction, and at least another portion bends in a second direction, the first direction being different from the second direction. In the embodiments described in this application, the curved section of the injection structure 4 can be S-shaped, in which case the curved section includes multiple sequentially connected bent tubes, and each bent tube is U-shaped or arc-shaped. For any two adjacent bends, the bending direction of one bend is different from that of the other. The bending directions of two adjacent bends are opposite, and when the two bends are connected, they form a serpentine tubular structure.

[0052] Alternatively, the curved section of the injection structure 4 can be spirally curved, meaning the shape of the curved section is the same as that of the spiral tube. In this case, the curved section includes multiple sequentially connected bends, and each bend is semi-circular in shape. For any two adjacent bends, their bending directions are opposite, and their projections onto the axial direction of the curved section form a complete ring.

[0053] For the injection structure 4, only a portion may be a curved pipe section. For example, the injection structure 4 may include a straight pipe section and a curved pipe section, with the straight pipe section connecting both ends of the curved pipe section. The entire injection structure 4 may also consist of curved pipe sections, i.e., the injection structure 4 may be a serpentine pipe or a spiral pipe. Because the flow channel extends along the curve within the curved pipe section, after the repair material is injected into the injection structure 4, the repair material will continuously collide with the pipe wall of the curved pipe section during its flow. Therefore, the curved pipe section, acting as the flow-blocking part 41, can slow down the flow of the repair material, making its flow more stable. Furthermore, the curved pipe section has a significant obstructive effect on the fluid; therefore, the flow-blocking part 41, being a curved pipe section of the injection structure 4, can provide a more reliable obstruction effect on the repair material.

[0054] refer to Figure 6 In some embodiments of this application, optionally, the lower housing 2 has a buffer structure 22, and the buffer structure 22 is disposed facing the liquid outlet 4b. When the repair material flows out from the liquid outlet 4b of the injection structure 4, its fluid trajectory will pass through the buffer structure 22. In other words, when the repair material flows out from the liquid outlet 4b of the injection structure 4, it will touch or impact the buffer structure 22. The buffer structure 22 can provide a dispersion effect to the repair material, so that the repair material is dispersed and injected into the receiving cavity 3. This can prevent the repair material from flowing violently in the receiving cavity 3, thereby reducing the impact of the repair material on the battery cell 100. In the embodiments of this application, the buffer structure 22 can specifically be a groove disposed on the lower housing 2, the bottom of the groove is spherical, and the opening of the groove is disposed facing the liquid outlet 4b. For example, the diameter of the groove is 10mm and the depth is 3mm. When the repair material flows out from the liquid outlet 4b, the repair material impacts the spherical surface of the groove, and under the dispersion effect of the spherical surface, the repair material is dispersed into multiple stable fluid streams. Alternatively, the buffer structure 22 can specifically be a convex bulge provided on the lower housing 2, with the surface of the convex bulge being spherical and the bulge protruding towards the outlet 4b. When the repair material flows out from the outlet 4b, the repair material impacts the spherical surface of the convex bulge, and under the dispersing effect of the spherical surface, the repair material is dispersed into multiple stable fluid streams.

[0055] refer to Figure 3In some embodiments of this application, for example, the cell casing includes a porous adsorption structure 5. The porous adsorption structure 5 is disposed within the liquid injection structure 4 to adsorb the exhaust gas generated by the secondary battery during operation. Specifically, in this application, the porous adsorption structure 5 can be a porous structure with adsorption effects, such as adsorption cotton or activated carbon. For example, the porous adsorption structure 5 is adsorption cotton with a thickness of 2mm-4mm. During the operation of the secondary battery, the exhaust gas generated can enter the liquid injection port and be adsorbed by the porous adsorption structure 5. This can suppress battery swelling and prevent the risk of internal short circuits caused by deformation of the cell 100 due to exhaust gas. Simultaneously, this can absorb harmful acidic gases generated by the secondary battery, avoiding environmental pollution and harm to human health.

[0056] refer to Figure 3 In some embodiments of this application, for example, the porous adsorption structure 5 is located at the end section of the injection structure 4 near the replenishment port 11, and the flow-blocking part 41 is located on the side of the porous adsorption structure 5 facing away from the replenishment port 11, serving to support the porous adsorption structure 5. Because the porous adsorption structure 5 is located at the end section of the injection structure 4 near the replenishment port 11, it can be removed from the replenishment port 11 when replenishing the repair material, preventing the porous adsorption structure 5 from interfering with the replenished repair material. The flow-blocking part 41, located on the side of the porous adsorption structure 5 facing away from the replenishment port 11, allows the porous adsorption structure 5 to be held at the end section near the replenishment port 11 by the flow-blocking part 41. This prevents the porous adsorption structure 5 from falling deep into the injection structure 4, thus facilitating the removal of the porous repair structure.

[0057] refer to Figure 3 , Figure 4 In some embodiments of this application, for example, the cell housing includes a semi-permeable membrane 6 for gas to pass through. Specifically, the semi-permeable membrane 6 may be a hydrophobic and breathable polytetrafluoroethylene membrane, which allows gas to pass freely through the membrane while keeping solvents out.

[0058] The baffle 21 includes a first baffle 211 and a second baffle 212. The first side of the first baffle 211 and the second baffle 212 serves as the inner wall of the injection structure 4, and the second side serves as the outer wall of the injection structure 4. An opening exists between the first baffle 211 and the second baffle 212, which is the outlet 4b of the injection structure 4. In the embodiments described in this application, the first baffle 211 and the second baffle 212 can be an integral structure, and the outlet 4b can specifically be a circular hole, square hole, triangular hole, etc., formed by the first baffle 211 and the second baffle 212. For example, the outlet 4b is a circular hole with a diameter of 5 mm. Alternatively, the first baffle 211 and the second baffle 212 can also be two plate structures arranged relatively spaced apart, with the gap between the two plate structures being the outlet 4b. One end of the semi-permeable membrane 6 is rotatably connected to the first baffle 211. For example, one end of the semi-permeable membrane 6 can be adhered to the first baffle 211 using flexible adhesive tape. The other end of the semipermeable membrane 6 is free relative to the first baffle 211 and the second baffle 212. When no repair material is injected into the injection structure 4, the semipermeable membrane 6 completely covers and seals the outlet 4b, and at this time, the other end of the semipermeable membrane 6 at least partially covers the second baffle 212. When repair material is injected into the injection structure 4, the semipermeable membrane 6 rotates and opens the outlet 4b, and at this time, the other end of the semipermeable membrane 6 is located on the second side of the second baffle 212, i.e., the outer wall of the injection structure 4. Alternatively, one end of the semipermeable membrane 6 can be fixedly bonded to the first baffle 211, and the other end of the semipermeable membrane 6 is free relative to the first baffle 211 and the second baffle 212. When no repair material is injected into the injection structure 4, the semipermeable membrane 6 completely covers and seals the outlet 4b, and at this time, the other end of the semipermeable membrane 6 at least partially covers the second baffle 212. When repair material is injected into the injection structure 4, the semipermeable membrane 6 deforms and opens the outlet 4b, and at this time, the other end of the semipermeable membrane 6 is located on the second side of the second baffle 212. The semi-permeable membrane 6 allows exhaust gas from the secondary battery to enter the injection structure 4 while preventing the original electrolyte from flowing back into the injection structure 4, thus avoiding the electrolyte affecting the adsorption of exhaust gas from the porous adsorption structure 5. During the injection of repair material, the semi-permeable membrane 6 can leave the outlet 4b open to minimize its impact. After the repair material is injected, negative pressure can be applied to the injection structure 4 to reseal the outlet 4b of the semi-permeable membrane 6.

[0059] Secondly, this application also provides a secondary battery, which includes a cell 100 and a cell casing as described in the first aspect.

[0060] Thirdly, this application also provides a battery pack, which includes the secondary batteries as described in the second aspect. Specifically, the battery pack has a housing, and multiple secondary batteries as described in the second aspect can be disposed within the housing.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0062] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or at least two of the features. In the description of this utility model, unless otherwise stated, "at least two" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0063] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "left", "right", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model 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 this utility model.

[0064] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0065] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or at least two embodiments or examples.

[0066] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A battery cell housing, characterized in that, include: Top cover (1), the top cover (1) having a liquid inlet (11) for adding repair material; The lower housing (2) and the top cover (1) form a receiving cavity (3), which is used to receive the battery cell (100). The liquid injection structure (4) is located in the receiving cavity (3). The liquid injection structure (4) includes a flow channel for fluid flow. At least a portion of the flow channel of the liquid injection structure (4) is provided with a flow-blocking part (41). The liquid injection structure (4) has an inlet (4a) and an outlet (4b). The inlet (4a) is connected to the replenishment port (11), and the outlet (4b) is connected to the receiving cavity (3).

2. The cell housing according to claim 1, characterized in that, The lower housing (2) is formed by a straight portion (2a) and a bent portion (2b), and the bent portion (2b) is connected between two adjacent straight portions (2a). The lower housing (2) also includes a baffle (21). The baffle (21) is located in the receiving cavity (3) and is fixedly connected to the bent part (2b). The baffle (21) and the bent part (2b) surround the liquid injection structure (4). The liquid injection structure has a first opening on the side facing the top cover (1), the first opening being used to form the liquid inlet (4a), or the baffle (21) of the liquid injection structure has a second opening, the second opening being used to form the liquid inlet (4a). There is a gap between the liquid injection structure and the bottom wall of the lower housing (2), the gap being used to form the liquid outlet (4b), or the baffle (21) of the liquid injection structure has a third opening, the third opening being used to form the liquid outlet (4b).

3. The cell housing according to claim 2, characterized in that, The surface of the bend (2b) in the injection structure (4) is provided with the flow-blocking part (41), and / or the surface of the baffle (21) in the injection structure (4) is provided with the flow-blocking part (41).

4. The cell housing according to claim 1, characterized in that, The liquid injection structure (4) is disposed in the receiving cavity (3), and at least a portion of the liquid injection structure (4) is a curved section, which forms the flow obstruction part (41). The curved pipe section includes a plurality of sequentially connected bent pipes, at least a portion of which bend in a first direction, and at least another portion of which bend in a second direction, wherein the first direction and the second direction are different.

5. The cell housing according to any one of claims 1-4, characterized in that, The lower housing (2) has a buffer structure (22) which is arranged toward the liquid outlet (4b) so that the fluid flowing out of the liquid outlet (4b) is dispersed when it passes through the buffer structure (22).

6. The cell housing according to any one of claims 1-4, characterized in that, The battery cell housing includes a porous adsorption structure (5); the porous adsorption structure (5) is disposed within the liquid injection structure (4).

7. The cell housing according to claim 6, characterized in that, The porous adsorption structure (5) is located at the end section of the liquid injection structure (4) near the liquid replenishment port (11), and the flow blocking part (41) is located on the side of the porous adsorption structure (5) facing away from the liquid replenishment port (11). The flow blocking part (41) is used to support the porous adsorption structure (5).

8. The cell housing according to claim 2, characterized in that, The battery cell housing includes a semi-permeable membrane (6) for gas to pass through; The baffle (21) includes a first baffle (211) and a second baffle (212). The first side of the first baffle (211) and the second baffle (212) serves as the inner wall of the liquid injection structure (4), and the second side serves as the outer wall of the liquid injection structure (4). An opening is provided between the first baffle (211) and the second baffle (212) to form the liquid outlet (4b). One end of the semipermeable membrane (6) is rotatably connected to the first baffle (211). When the semipermeable membrane (6) closes the liquid outlet (4b), the other end of the semipermeable membrane (6) is located on the second side of the second baffle (212), and the other end of the semipermeable membrane (6) at least partially covers the second baffle (212).

9. A secondary battery, characterized in that, It includes the cell housing and cell as described in any one of claims 1-8, wherein the cell is disposed within the cell housing.

10. A battery pack, characterized in that, Includes the secondary battery as described in claim 9.

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