Patent Application
20250226495
The present disclosure relates to the field of battery technologies, and more particularly, to a cell battery, a battery pack, and an electrical device.
In the related art, a cell battery has poor pressure relief performance. Pressure relief cannot be completed in time when the cell battery has a high pressure, resulting in a risk of thermal runaway.
Embodiments of the present disclosure are to provide a cell battery, which can satisfy high pressure relief requirements.
Embodiments of the present disclosure are also to provide a battery pack including the above cell battery.
Embodiments of the present disclosure are also to provide an electrical device including the above battery pack.
According to an embodiment of the present disclosure, a cell battery is provided. The cell battery includes a housing, a first end cover provided at an end of the housing, and a second end cover provided at the other end of the housing. The first end cover includes a first base cover and a first explosion-proof valve mounted at the first base cover. The second end cover includes a second base cover and a second explosion-proof valve mounted at the second base cover.
According to embodiments of the present disclosure, a battery pack is provided. The battery pack includes the cell battery according to any one of the above embodiments.
According to embodiments of the present disclosure, an electrical device is provided. The electrical device includes the battery pack according to the above embodiments.
Additional aspects and advantages of the present disclosure will be provided at least in part in the following description, or will become apparent at least in part from the following description, or can be learned from practicing of the present disclosure.
The above and/or additional aspects and advantages of the present disclosure will become more apparent and more understandable from the following description of embodiments taken in conjunction with the accompanying drawings.
Embodiments of the present disclosure will be described in detail below with reference to examples thereof as illustrated in the accompanying drawings, throughout which same or similar elements, or elements having same or similar functions, are denoted by same or similar reference numerals. The embodiments described below with reference to the drawings are illustrative only, and are intended to explain, rather than limiting, the embodiments of the present disclosure.
In the description of the present disclosure, it should be understood that, the orientation or the position indicated by terms such as “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “over,” “below,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “anti-clockwise,” “axial,” “radial,” and “circumferential” should be construed to refer to the orientation and the position as shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the pointed device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure.
In the description of the present disclosure, “the first feature” and “the second feature” may include one or more of these features. “Plurality” means two or more. The first feature “on” or “under” the second feature may mean that the first feature is in direct contact with the second feature, or the first and second features are in indirect contact through another feature between the first and second features. The first feature “above” the second feature means that the first feature is directly above or obliquely above the second feature, or simply means that the level of the first feature is higher than that of the second feature.
In the related art, a cell battery has poor pressure relief performance. Pressure relief cannot be completed in time when the cell battery has a high internal pressure, resulting in a risk of thermal runaway. For example, when the cell battery has a large height, a demand for pressure relief becomes more stringent. However, a structure of the cell battery in the related art restricts the height of the cell battery from being increased, which impacts applicability of the cell battery.
Therefore, embodiments of the present disclosure provide a cell battery, which can realize rapid pressure relief, and release pressure through two ends of the cell battery, and thus can satisfy high pressure relief requirements, thereby effectively reducing the risk of thermal runaway. Further, the height of the cell battery is not restricted by the pressure relief, which facilitates flexible design of the cell battery in size as desired. For example, pressure relief requirements of the cell battery with a height greater than 140 mm can be satisfied.
A cell battery 100 according to the embodiments of the present disclosure is described below with reference to the accompanying drawings.
As illustrated in
The first end cover 100a is provided at an end of the housing 10, and the second end cover 100b is provided at the other end of the housing 10, in such a manner that the first end cover 100a, the second end cover 100b, and the housing 10 cooperate to define a mounting cavity. The mounting cavity is configured for mounting of a cell to provide protection for the cell.
The first end cover 100a includes a first base cover 1a and a first explosion-proof valve 20 mounted at the first base cover 1a.
The second end cover 100b includes a second base cover 1b and a second explosion-proof valve 30 mounted at the second base cover 1b.
Both the first explosion-proof valve 20 and the second explosion-proof valve 30 are capable of pressure relief. Through the pressure relief by double explosion-proof valves, a gas in the mounting cavity can be more quickly released to avoid explosion of the cell battery 100. Further, the first explosion-proof valve 20 and the second explosion-proof valve 30 are located at two ends of the cell battery 100, respectively. In this way, the pressure relief can be carried out at two ends of the cell battery 100, and the gas in the mounting cavity does not need to flow from one end to the other end of the cell battery 100 before being released, which can satisfy the pressure relief requirements of the cell battery 100 with a larger size.
For example, in an embodiment in which the cell battery 100 is a cylindrical battery, the first explosion-proof valve 20 and the second explosion-proof valve 30 are located at two axial ends of the cylindrical battery, respectively, and a gas in the cylindrical battery can be released from the two axial ends, reducing a flow path required for the gas release. For example, for a cylindrical battery with an axial height greater than 140 mm, pressure relief requirements are higher. A cooperation between the first explosion-proof valve 20 and the second explosion-proof valve 30 according to the embodiments of the present disclosure can better satisfy the pressure relief requirements of the cell battery 100 with a larger height. It should be noted that the above embodiments do not limit a shape and a size of
the cell battery 100 according to the embodiments of the present disclosure. Actually, the cell battery 100 according to the embodiments of the present disclosure may be the cylindrical battery, a prismatic battery, or the like. A height of the cell battery 100 (that is, an overall size of the cell battery 100 in a direction from the first end cover 100a to the second end cover 100b) may be greater than 140 mm, or may be smaller than or equal to 140 mm, which are all within the scope of the present disclosure.
With the cell battery 100 according to the embodiments of the present disclosure, since the first end cover 100a includes the first explosion-proof valve 20 and the second end cover 100b includes the second explosion-proof valve 30, the first explosion-proof valve 20 and the second explosion-proof valve 30 can perform the pressure relief through two ends of the cell battery 100. As a result, a pressure relief capacity is improved, which can satisfy higher pressure relief requirements, thereby significantly reducing the risk of thermal runaway.
In some embodiments, the first end cover 100a includes the first base cover 1a, the first pole 20a, the first explosion-proof valve 20, and a first current collector disk 30a. The first pole 20a and the first explosion-proof valve 20 are mounted on the first base cover 1a. The first current collector disk 30a is located at a side of the first base cover 1a facing towards the housing 10, and the first current collector disk 30a is electrically connected to the first pole 20a. The first base cover 1a has an electrolyte injection hole 105. The second end cover 100b includes the second base cover 1b, a second pole 20b, the second explosion-proof valve 30, and a second current collector disk 30b. The second pole 20b and the second explosion-proof valve 30 are mounted on the second base cover 1b. The second current collector disk 30b is located at a side of the second base cover 1b facing towards the housing 10, and the second current collector disk 30b is electrically connected to the second pole 20b. The first base cover 1a may cover one end of the housing 10 and the second base
cover 1b may cover the other end of the housing 10 to define the mounting cavity together with the housing 10. In addition, the first base cover 1a may serve as a mounting base for the first pole 20a, the first explosion-proof valve 20, and the first current collector disk 30a. The second base cover 1b may serve as a mounting base for the second pole 20b, the second explosion-proof valve 30, and the second current collector disk 30b.
One of the first pole 20a and the second pole 20b may be a positive pole, and the other one of the first pole 20a and the second pole 20b may be a negative pole. Correspondingly, one of the first current collector disk 30a and the second current collector disk 30b is a positive current collector disk, and the other one of the first current collector disk 30a and the second current collector disk 30b is a negative current collector disk. One of the first end cover 100a and the second end cover 100b is a positive end cover, and the other one of the first end cover 100a and the second end cover 100b is a negative end cover. In other words, the positive pole and the negative pole are provided at different end covers, respectively, to provide a simpler electrical connection structure on each end cover to facilitate structural arrangement. In addition, a risk of short circuiting between the positive pole and the negative pole due to space limitations is reduced.
A connection manner between the pole and the base cover is not limited by the present disclosure. For example, as illustrated in
In addition, the positive pole and the negative pole may be electrically connected to two ends of the cell, respectively. For example, the cell may be provided with a positive tab and a negative tab at two ends of the cell, respectively. The first current collector disk 30a is located at the side of the first base cover 1a facing towards the housing 10. The second current collector disk 30b is located at the side of the second base cover 1b facing towards the housing 10, in such a manner that the positive pole may be connected to the positive tab by the positive current collector disk, and the negative pole may be electrically connected to the negative tab by the negative current collector disk. The positive tab and the negative tab are located at different ends, respectively. A positive electrical connection structure and a negative electrical connection structure are located at different ends. In this way, a risk of short circuits can be effectively reduced, and arrangement of the tabs and connection between the electrical connection structures are facilitated.
In addition, the first base cover 1a has the electrolyte injection hole 105. In other words, one of the positive end cover and the negative end cover has the electrolyte injection hole 105 to facilitate electrolyte injection and reduce the number of openings in the cell battery 100.
With the cell battery 100 according to the embodiment of the present disclosure, the first end cover 100a includes the first pole 20a, the first explosion-proof valve 20, and the first current collector disk 30a. Further, the second end cover 100b includes the second pole 20b, the second explosion-proof valve 30, and the second current collector disk 30b. In this way, the first explosion-proof valve 20 and the second explosion-proof valve 30 can perform the pressure relief through two ends of the cell battery 100. As a result, the pressure relief capacity is improved, which can satisfy higher pressure relief requirements, thereby significantly reducing the risk of thermal runaway. In addition, the first pole 20a and the second pole 20b are located at the two ends of the cell battery 100, respectively, so as to simplify a structure of the first end cover 100a and a structure of the second end cover 100b, improving sealing performance of the end cover and product quality.
According to some embodiments of the present disclosure, a projection of the first explosion-proof valve 20 in an axial direction of the cell battery 100 at least partially overlaps with a projection of the second explosion-proof valve 30 in the axial direction of the cell battery 100. In other words, an arrangement position of the first explosion-proof valve 20 on the first base cover 1a is close to an arrangement position of the second explosion-proof valve 30 on the second base cover 1b. For example, in an embodiment in which the explosion valve is arranged eccentrically with respect to a centerline of the base cover, the first explosion-proof valve 20 and the second explosion-proof valve 30 are substantially located at a same side relative to the centerline. Therefore, during assembly, the first explosion-proof valve 20 and the second explosion-proof valve 30 may be assembled at the same side, and thus an assembly process is simplified, thereby improving an assembly efficiency.
In some exemplary embodiments, the projection of the first explosion-proof valve 20 in the axial direction of the cell battery 100 completely overlaps with the projection of the second explosion-proof valve 30 in the axial direction of the cell battery 100. In other words, the first explosion-proof valve 20 is identical with the second explosion-proof valve 30. The arrangement position of the first explosion-proof valve 20 on the first base cover 1a is identical with the arrangement position of the second explosion-proof valve 30 on the second base cover 1b. In this way, not only assembly reliability can be further improved, but also versatility of the explosion-proof valve can be enhanced, lowering a manufacturing cost.
For example, as illustrated in
In some embodiments of the present disclosure, as illustrated in
When heat generated in an interior of the cell battery 100 is too high, a high-pressure fluid may be generated and flow through the first explosion-proof valve 20 and the second explosion-proof valve 30, and then be discharged via the first exhaust channel 101a and the second exhaust channel 101b. In this way, ventilation and explosion-proof functions can be provided.
In some embodiments, as illustrated in
The first protective member 61a may provide protection for the first explosion-proof valve 20. The second protective member 61b may provide protection for the second explosion-proof valve 30. In the cell process, welding spatter, electrolyte injection, and other foreign materials may contaminate the first explosion-proof valve 20 and the second explosion-proof valve 30, thereby affecting ventilation performance. With the first protective member 61a and the second protective member 61b, foreign materials can be effectively prevented from reaching a surface of the first explosion-proof valve 20 and a surface of the second explosion-proof valve 30.
In some embodiments, the explosion-proof valves may be welded and assembled to the respective base covers. The protective members may be attached to and fixed to the respective base covers.
In some embodiments, as illustrated in
According to some embodiments of the present disclosure, as illustrated in
In addition, the first base plate 10a is provided with the first through-hole 102a and the first communication channel 103a. The first hollowed-out region 512a is located at the first insulation cover 51a. The first exhaust channel 101a includes the first through-hole 102a and the first hollowed-out region 512a. The first explosion-proof valve 20 is mounted between the first base plate 10a and the first insulation cover 51a. Mounting and position-limiting of the first explosion-proof valve 20 can be realized by the first base plate 10a and the first insulation cover 51a. The first explosion-proof valve 20 may be stably located at the first exhaust channel 101a, providing reliable explosion protection. In addition, the first hollowed-out region 512a is located at the first insulation cover 51a, which not only facilitates ventilation and explosion protection but also ensures structural strength of the first insulation cover 51a, preventing the first insulation cover 51a from being perforated in a large area, and thus affecting the structural strength.
According to some embodiments of the present disclosure, as illustrated in
According to some embodiments of the present disclosure, as illustrated in
Compared with an ultrasonic welding method in the related art, the laser welding method can greatly improve sealing performance and avoid a problem of puncturing a sealing structure during ultrasonic welding. Compared with riveting in the related art, this method can eliminate need for perforating in the first current collector disk 30a and the second current collector disk 30b, reducing seams that needs to be sealed, and thus improving the sealing.
In some embodiments, as illustrated in
In some specific embodiments, a laser welding path is in a continuous annular shape, which provides a larger welding area, resulting in higher strength and a more reliable connection. Further, the current-carrying capacity is enhanced, making the welding operation more convenient.
In some embodiments, the first base plate 10a and the second base plate 10b may be made of lightweight aluminum sheets, such as Al 3003, by stamping aluminum material.
In some embodiments, the first insulation cover 51a and the second insulation cover 51b may be injection molded from PP, which satisfies manufacturing requirements for relatively complex structures. The first insulation cover 51a and the second insulation cover 51b may be made of a transparent material or may be colored by adding a color masterbatch to produce black or other colors. A material of the first pole 20a and a material of the second pole 20b may be selected as desired. For example, the negative pole may be made of copper, such as T2 copper, and the positive pole may be made of aluminum, such as Al 1060 or Al 3003.
A material of the first current collector disk 30a and a material of the second current collector disk 30b may be selected as desired. For example, the negative current collector disk may be stamped from a nickel-plated copper material. The positive current collector disk may be made of aluminum, such as Al 1060.
In some embodiments of the present disclosure, as illustrated in
In a manufacturing process, the first current collector disk 30a may be mounted at a side of the first base cover 1a, allowing the first limiting rib 511a to be engaged with the edge of the first current collector disk 30a to limit the first current collector disk 30a in a direction perpendicular to an axis of the first pole 20a. Then, the first current collector disk 30a is connected to the first pole 20a, for example, through laser welding, preventing misalignment of the first current collector disk 30a during connection, which would affect connection reliability and sealing.
In some embodiments of the present disclosure, as illustrated in
According to some embodiments of the present disclosure, as illustrated in
In some embodiments, as illustrated in
In some exemplary embodiments, the first seal 40a may be made of rubber or silicone, and is elastically deformable by being compressed by the first outer protrusion 21a and the first base cover 1a to improve sealing.
According to some embodiments of the present disclosure, as illustrated in
In some embodiments, as illustrated in
As illustrated in
In some embodiments, as illustrated in
In some embodiments, as illustrated in
In some embodiments, the first pole 20a and the second pole 20b may be manufactured using cold heading.
In some embodiments, the first spacer 52a and the second spacer 52b may be injection molded from PP or PPS. A spacer corresponding to a negative electrode is made of an insulating material. When the spacer is made of PPS, glass fibers may further be added to increase mechanical strength. A spacer corresponding to a positive electrode may have with conductive carbon and glass fibers added.
In some embodiments of the present disclosure, as illustrated in
An arrangement position of the first limiting recess 521a may be interchanged with an arrangement position of the first limiting protrusion 71a. That is, the first pressing block 70a has the first limiting recess 521a, and the first spacer 52a is provided with the first limiting protrusion 71a. In other words, one of the first pressing block 70a and the first spacer 52a has a first limiting recess 521a, and the other one of the first pressing block 70a and the first spacer 52a is provided with a first limiting protrusion 71a engaged into the first limiting recess 521a. The first limiting protrusion 71a has a non-circular cross-section perpendicular to an axis of the first pole 20a.
In some embodiments of the present disclosure, as illustrated in
It should be noted that the cross-section of each of the first limiting protrusion 71a and the second limiting protrusion 71b includes, but is not limited to a hexagonal shape illustrated in
In some embodiments of the present disclosure, as illustrated in
An arrangement position of the third limiting recess 104a may be interchanged with an arrangement position of the third limiting protrusion 522a. That is, the first spacer 52a has the third limiting recess 104a, and the first base cover 1a is provided with the third limiting protrusion 522a. In other words, one of the first base cover 1a and the first spacer 52a has the third limiting recess 104a, and the other one of the first base cover 1a and the first spacer 52a is provided with the third limiting protrusion 522a engaged into the third limiting recess 104a. The third limiting protrusion 522a has a non-circular cross-section perpendicular to the axis of the first pole 20a.
In some embodiments of the present disclosure, as illustrated in
It should be noted that the cross-section of each of the third limiting protrusion 522a and the fourth limiting protrusion 522b includes, but is not limited to, a cross shape illustrated in
An assembly process of the first end cover 100a according to some embodiments of the present disclosure is described below with reference to the accompanying drawings. From the following description, an assembly process of the second end cover 100b may be understood.
According to some embodiments of the present disclosure, as illustrated in
A battery pack according to embodiments of the present disclosure includes the cell battery 100 according to the embodiments of the present disclosure. Since the cell battery 100 according to the embodiments of the present disclosure has the above beneficial technical effects, with the battery pack according to the embodiments of the present disclosure, since the first end cover 100a includes the first explosion-proof valve 20 and the second end cover 100b includes the second explosion-proof valve 30, the first explosion-proof valve 20 and the second explosion-proof valve 30 can perform the pressure relief through two ends of the cell battery 100. As a result, the pressure relief capacity is improved, which can satisfy the higher-pressure relief requirements, thereby significantly reducing the risk of thermal runaway.
As a new type of energy storage device, a power battery is widely used in automobile, aerospace, high-speed rail, and other fields. With the development of power battery industry, higher requirements for energy density, cycle performance, and other indicators of the power battery are required. During use of the power battery, thermal runaway may occur in an internal cell due to various reasons. When thermal runaway occurs in the cell, a large amount of gas may be generated in a short period of time. When the gas inside the cell battery 100 cannot be discharged in time, there is a risk of explosion.
To reduce the safety hazards associated with an increased internal pressure due to the thermal runaway in the cell battery, an explosion-proof valve is typically mounted at an end of the cell battery. When the gas pressure inside the cell battery increases, the explosion-proof valve opens to allow the gas to be discharged from the cell battery, thereby reducing the safety hazards. In the related art, only one explosion-proof valve is typically provided. When the explosion-proof valve fails or reactions in the cell battery are too intense, the gas inside the cell battery cannot be discharged in time, which would result in significant safety hazards.
The cell battery 100 according to the embodiments of the present disclosure is described below with reference to
As illustrated in
The housing 10 is in a cylindrical shape. The first explosion-proof valve 20 and the second explosion-proof valve 30 are provided at two axial ends of the housing 10, respectively. An opening pressure of the first explosion-proof valve 20 is unequal to an opening pressure of the second explosion-proof valve 30.
In an exemplary embodiment of the present disclosure, the first explosion-proof valve 20 and the second explosion-proof valve 30 are provided at two axial ends of the housing 10 of the cell battery 100, respectively. In addition, an opening pressure of the first explosion-proof valve 20 is unequal to an opening pressure of the second explosion-proof valve 30. When the cell battery 100 just experiences the thermal runaway, gas is generated in the cell battery, and the gas expands inside the cell battery 100 and compresses the housing 10. When the gas in the cell battery 100 reaches a predetermined pressure, one of the first explosion-proof valve 20 and the second explosion-proof valve 30 which has a smaller opening pressure opens, allowing the gas to be smoothly discharged through the first explosion-proof valve 20 or the second explosion-proof valve 30. If the thermal runaway in the cell battery 100 becomes relatively intense, a pressure inside the housing 10 continues to rise, causing one of the first explosion-proof valve 20 and the second explosion-proof valve 30 which has a higher opening pressure to open. In this case, both the first explosion-proof valve 20 and the second explosion-proof valve 30 are in an open state, allowing the gas to be released by both the first explosion-proof valve 20 and the second explosion-proof valve 30 simultaneously.
With the cell battery 100 according to the embodiments of the present disclosure, by providing two explosion-proof valves with different opening pressures, when severe thermal runaway occurs inside the cell battery 100, the first explosion-proof valve 20 and the second explosion-proof valve 30 can successively open to allow the gas to be released in time, thereby reducing the safety hazards.
It should be noted that a relationship between the opening pressure of the first explosion-proof valve 20 and the opening pressure of the second explosion-proof valve 30 is not specifically limited. For example, the opening pressure of the first explosion-proof valve 20 may be smaller than the opening pressure of the second explosion-proof valve 30, or the opening pressure of the first explosion-proof valve 20 may be greater than the opening pressure of the second explosion-proof valve 30, which may be selected as necessary.
In some embodiments, a difference between the opening pressure of the first explosion-proof valve 20 and the opening pressure of the second explosion-proof valve 30 is greater than or equal to 0.1 MPa.
In an exemplary embodiment of the present disclosure, by setting different opening pressures for the first explosion-proof valve 20 and the second explosion-proof valve 30, when the thermal runaway occurs in the cell battery 100, the explosion-proof valve with a smaller opening pressure may be opened. Then, when the thermal runaway becomes severe and an internal pressure of the battery 100 continues to rise, the explosion-proof valve with a greater opening pressure may then be opened. In this way, the gas can be discharged in time. Since the first explosion-proof valve 20 and the second explosion-proof valve 30 have different structural strengths, the first explosion-proof valve 20 and the second explosion-proof valve 30 have different opening pressures. The explosion-proof valve with the greater opening pressure has a higher structural strength. When the cell battery 100 is used normally, the cell battery 100 with the higher structural strength is less likely to be damaged, and thus the cell battery 100 is more reliable.
In addition, when the thermal runaway occurs in the cell battery 100 and gas generation begins inside the cell battery 100, pressure relief can be completed by opening the explosion-proof valve with a lower pressure. When the thermal runaway is controlled in this time and gas generation of the cell battery 100 is small, the pressure relief requirements of the cell battery 100 can be satisfied by opening one explosion-proof valve, which can prevent a high-temperature gas generated inside the cell battery 100 from affecting surrounding cell batteries 100. In later maintenance, only the damaged cell battery 100 needs to be replaced.
Therefore, only one explosion-proof valve is opened when a gas pressure inside the cell battery 100 is relatively low. Therefore, reliability of the cell battery is improved.
As illustrated in
In an exemplary embodiment of the present disclosure, when the thermal runaway occurs in the cell battery 100, a large amount of gas is generated inside the cell battery 100. The internal pressure of the housing 10 rapidly increases. Pressure is exerted by the gas to the first body 21 and the second body 31 that are located at two ends of the housing 10. In this case, the first body 21 and the second body 31 tend to break outwardly. Since the first body 21 has a smaller thickness and a lower structural strength at the first groove 211, and the second body 31 has a smaller thickness and a lower structural strength at the second groove 311, when a predetermined pressure is reached in the housing 10, the first body 21 and the second body 31 rupture from the first groove 211 and the second groove 311, respectively.
Therefore, the first explosion-proof valve 20 and the second explosion-proof valve 30 can be opened at an indentation when being subject to the pressure. By controlling a depth of the indentation, the opening pressure can be controlled, enhancing reliability of the cell battery 100.
In some embodiments, the first groove 211 of the first body 21 is in a cross shape. The second groove 311 of the second body 31 is in a cross shape. When the thermal runaway occurs in the cell battery 100 and the pressure in the housing 10 rises rapidly, a gas generated by the thermal runaway may compress the first explosion-proof valve 20 and the second explosion-proof valve 30 at two ends of the housing 10, and a center of the first body 21 and a center of the second body 31 may bulge and deform. When the pressure in the housing 10 rises to some extent, the first body 21 may break from a cross center of the first groove 211, and the second body 31 may also split from a cross center of the second groove 311, thereby achieving the pressure relief.
In some embodiments, the first groove 211 of the first body 21 is circular. The second groove 311 of the second body 31 is circular. Circular indentations are located at the center of the first body 21 and the center of the second body 31, respectively. When the thermal runaway occurs in the cell battery 100 and the pressure in the housing 10 rises rapidly, the gas generated by the thermal runaway may compress the first explosion-proof valve 20 and the second explosion-proof valve 30 at two ends of the housing 10, and a center of the first body 21 and a center of the second body 31 may bulge and deform. When the pressure in the housing 10 rises to some extent, the first body 21 may break from a circular first groove 211, and the second body 31 may also split from a circular second groove 311, thereby achieving the pressure relief.
It should be noted that a shape of the first groove 211 and a shape of the second groove 311 are not specifically limited here. For example, both of the first groove 211 and the second groove 311 may have a cross shape or a circular shape, or one of the first groove 211 and the second groove 311 may have a cross shape and the other one of the first groove 211 and the second groove 311 may have a circular shape, which may be provided as desired.
In some embodiments, the first groove 211 has a depth unequal to a depth of the second groove 311.
In an exemplary embodiment of the present disclosure, as the indentation is deeper, the structural strength becomes lower. For convenience of understanding, as an example, the first groove 211 has a greater depth than the second groove 311. When the thermal runaway occurs in the cell battery 100, the pressure in the housing 10 increases, and the first groove 211 and the second groove 311 tend to break outwardly. When the pressure in the housing 10 reaches a predetermined level, a deeper depth of the first groove 211 results in lower structural strength for the first explosion-proof valve 20. In this case, when the pressure in the housing 10 reaches the opening pressure of the first explosion-proof valve 20, the first groove 211 ruptures under the pressure, thereby releasing the gas in the housing 10. When the thermal runaway in the cell battery 100 become too intense, which results in generation of a large volume of gas in the housing 10, in this case the first explosion-proof valve 20 cannot be able to relieve the pressure in the housing 10 in time. Therefore, the pressure in the cell battery 100 continues to rise and eventually reaches the opening pressure of the second explosion-proof valve 30. In this case, the second groove 311 ruptures under pressure, and both the first explosion-proof valve 20 and the second explosion-proof valve 30 open simultaneously to relieve the pressure in the housing 10.
Therefore, the number of the opened explosion-proof valves can be controlled according to a value of the internal pressure of the cell battery 100, thereby improving reliability of the cell battery 100.
It should be noted that a relative depth of the first groove 211 to the second groove 311 is not specifically limited here. The depth of the first groove 211 may be greater than the depth of the second groove 311, or the depth of the first groove 211 may be smaller than the depth of the second groove 311, as long as the first groove 211 and the second groove 311 have different depths, which may be set as desired.
It should be further noted that, a material of the first body 21 and a material of the second body 31 are not specifically limited here. The first body 21 and the second body 31 may be made of metal sheets or plastic sheets with high structural strength, which may be provided as desired.
In some embodiments, the first body 21 and the second body 31 are each made of an aluminum sheet. A difference between the depth of the first groove 211 and the depth of the second groove 311 is greater than or equal to 90 micrometers.
In an exemplary embodiment of the present disclosure, the aluminum sheet has a predetermined degree of ductility. When the cell battery 100 is subjected to compression or impact to be in contact with the first explosion-proof valve 20 or the second explosion-proof valve 30, the thermal runaway may not occur in the cell battery 100. In this case, the first body 21 with the predetermined ductility and the second body 31 with the predetermined ductility can prevent the first explosion-proof valve 20 or the second explosion-proof valve 30 from rupturing due to the impact. In this way, the reliability of the cell battery 100 is enhanced.
When the thermal runaway occurs in the cell battery 100, the gas is generated in the cell battery 100, and the pressure in the housing 10 rises rapidly. The first body 21 or the second body 31 bulges outwardly under the pressure of the gas in the housing 10. When deformation reaches a certain extent, the first body 21 or the second body 31 ruptures, and thus the gas in the housing 10 is discharged, relieving the internal pressure. As the thermal runaway intensifies, the internal pressure of the housing 10 continues to rise. When the predetermined pressure is reached, the other one of the first body 21 or the second body 31 may rupture. The pressure of the cell battery 100 is released simultaneously by both the first explosion-proof valve 20 and the second explosion-proof valve 30 at two ends of the housing 10.
By controlling the difference between the depth of the first groove 211 and the depth of the second groove 311 to be greater than or equal to 90 micrometers, the opening pressure of the first explosion-proof valve 20 and the opening pressure of the second explosion-proof valve 30 can be controlled, and an opening interval between the first explosion-proof valve 20 and the second explosion-proof valve 30 can be controlled, in such a manner that the cell battery 100 can quickly release the pressure of the cell battery 100 while having high reliability.
Therefore, the number of the opened explosion-proof valves can be controlled according to the value of the internal pressure of the cell battery 100, thereby improving the reliability of the cell battery 100 while enhancing safety of the cell battery 100.
It should be noted that the first body 21 and the second body 31 may also be made of other metal materials, such as a copper sheet or an iron sheet, which may be selected as desired.
As illustrated in
In an exemplary embodiment of the present disclosure, when the first body 21 ruptures at the first groove 211, the first body 21 may rupture along the edge of the first body 21. When the second body 31 ruptures at the second groove 311, the second body 31 may rupture along the edge of the second body 31. In this case, the first explosion-proof valve 20 and the second explosion-proof valve 30 each have a large opening area, and thus the pressure in the housing 10 can be quickly released.
As the thermal runaway of the cell battery 100 continues, a rate at which the gas is generated in the housing 10 also continues to increase. A rate at which the gas is generated in the housing 10 when the first body 21 ruptures is different from a rate at which the gas is generated in the housing 10 when the second body 31 ruptures. By setting the area of the first body 21 and the area of the second body 31 to be different from each other, the sheet with a small area may be opened immediately after the thermal runaway occurs when the rate of the gas is small, and then a sheet with a large area may be opened when the thermal runaway becomes severe and the rate of the gas is large. Therefore, timely pressure relief in the housing 10 is ensured.
Therefore, a gas discharge rate can be adjusted based on the area of the first body 21 and the area of the second body 31, and thus the gas generated due to the thermal runaway can be quickly discharged, thereby reducing safety hazards.
In some embodiments, the first body 21 includes a first connection segment 212. Two ends of the first connection segment 212 are connected to two ends of the first groove 211, respectively. A first opening region 213 is enclosed by the first connection segment 212 and the first groove 211. The second body 31 includes a second connection segment 312. Two ends of the second connection segment 312 are connected to two ends of the second groove 311, respectively. A second opening region 313 is enclosed by the second connection segment 312 and the second groove 311.
In an exemplary embodiment of the present disclosure, when the thermal runaway occurs in the cell battery 100 and the gas is generated internally, the first explosion-proof valve 20 and the second explosion-proof valve 30 may rupture sequentially. Since the first opening region 213 is connected to the first body 21 by the first connection segment 212, when the first opening region 213 ruptures, the first connection segment 212 can prevent the first opening region 213 from flying out due to the impact of the gas. The second opening region 313 is connected to the second body 31 by the second connection segment 312. When the second opening region 313 ruptures, the second connection segment 312 can prevent the second opening region 313 from flying out due to the impact of the gas. Therefore, safety is improved.
As illustrated in
It should be understood that the connection portion 22 is connected to two ends of the housing 10 to allow the first explosion-proof valve 20 and the second explosion-proof valve 30 to be fixed to the housing 10. Here, there is no specific limitation on a connection manner between the connection portion 22 and the housing 10. The connection portion 22 may be engaged with, bonded to, or welded to the housing 10, which may be selected as desired, as long as the connection portion 22 is stably connected to two ends of the housing 10.
As illustrated in
In an exemplary embodiment of the present disclosure, the first explosion-proof valve 20 is integrally formed at one end of the housing 10. The second explosion-proof valve 30 is connected to the other end of the housing 10 through the first engagement groove 11. The opening pressure of the first explosion-proof valve 20 and the opening pressure of the second explosion-proof valve 30 may be different from each other according to different connection methods. Since the second explosion-proof valve 30 is connected to the housing 10 through the first engagement groove 11, structural strength of the second explosion-proof valve 30 is lower than that of the first explosion-proof valve 20. Therefore, when the thermal runaway occurs in the cell battery 100, the second explosion-proof valve 30 is opened. When the internal pressure of the housing 10 continues to rise and reaches a predetermined level, the first explosion-proof valve 20 is opened.
Therefore, the opening pressure of the first explosion-proof valve 20 is different from the opening pressure of the second explosion-proof valve 30. The number of the opened explosion-proof valves can be selected according to a thermal runaway situation of the cell battery 100, thereby reducing safety hazards when the thermally runaway occurs in the cell battery 100.
In some embodiments, an end surface of the housing 10 (i.e., the first base cover 1a) has a third groove 214 extending in an arc shape. The first explosion-proof valve 20 is formed by the third groove 214 and a region enclosed by the third groove 214.
In an exemplary embodiment of the present disclosure, when the housing 10 of the cell battery 100 is manufactured, a sealing structure may be formed on the end surface of the housing 10 through an integral molding process. In addition, the third groove 214 can be provided at a bottom end surface, improving manufacturing efficiency of the housing 10. After loading a wound core and electrolyte into an open end of the housing 10, the other end of the housing 10 may be sealed to form an enclosed cell battery structure. When the thermal runaway occurs in the cell battery 100, gas generation in the cell battery increases the internal pressure of the cell battery 100. Under this pressure, the first explosion-proof valve 20 can rupture at the third groove 214, releasing the internal pressure of the cell battery 100 while ensuring safety of the cell battery 100.
Therefore, the first explosion-proof valve 20 and the housing 10 are integrally formed, which can reduce difficulty of manufacturing the cell battery 100 and improve the manufacturing efficiency.
In some embodiments, the second explosion-proof valve 30 is connected at the first engagement groove 11 through welding. Unlike the first explosion-proof valve 20 formed integrally on the housing 10, by welding the second explosion-proof valve 30 and the housing 10, the strength of the connection between the second explosion-proof valve 30 and the housing is lower than that of the connection between the first explosion-proof valve 20 and the housing. Therefore, the second explosion-proof valve 30 is opened when the thermal runaway occurs in the cell battery 100. When the internal pressure of the housing 10 continues to rise and reaches a predetermined level, the first explosion-proof valve 20 is opened.
Therefore, the number of the opened explosion-proof valves can be selected according to the thermal runaway situation of the cell battery 100, thereby reducing the safety hazards when the thermally runaway occurs in the cell battery 100.
As illustrated in
In some embodiments, the second explosion-proof valve 30 is connected at the first engagement groove 11 through welding. Therefore, the number of the opened explosion-proof valves can be selected according to the thermal runaway situation of the cell battery 100, thereby reducing the safety hazards when the cell battery 100 is thermally runaway.
In some embodiments, as illustrated in
A battery pack is provided according to embodiments of the present disclosure.
The battery pack includes the cell battery 100 according to any one of the above embodiments.
An electrical device is provided according to embodiments of the present disclosure. The electrical device includes the battery pack according to the above embodiments.
Other components and operations of the battery pack and the electrical device according to the embodiments of the present disclosure are known to those of ordinary skill in the art, and thus details thereof will be omitted here.
In the description of the present disclosure, it should be noted that, unless otherwise clearly stipulated and limited, terms such as “mount,” “connect,” and “connect to” should be understood in a broad sense. For example, it may be a fixed connection or a detachable connection or connection as one piece; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate; or internal communication of two components. For those of ordinary skill in the art, specific meanings of the above-mentioned terms in the present disclosure can be understood according to specific circumstances.
Reference throughout this specification to terms such as “embodiments,” “a specific example,” and “examples,” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. The appearances of the above phrases in various places throughout this specification are not necessarily referring to the same embodiment or example. In addition, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present disclosure have been illustrated and described, it is conceivable for those of ordinary skill in the art that various changes, modifications, replacements, and variations can be made to these embodiments without departing from the principles and spirit of the present disclosure. The scope of the present disclosure shall be defined by the claims as appended and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202222583311.8 | Sep 2022 | CN | national |
| 202222964548.0 | Nov 2022 | CN | national |
This application is a continuation of International Application No. PCT/CN2023/071607, filed on Jan. 10, 2023, which claims priority to Chinese patent applications Nos. 202222964548.0 and 202222583311.8, filed by XIAMEN HITHIUM ENERGY STORAGE TECHNOLOGY CO., LTD. on Nov. 3, 2022 and Sep. 28, 2022, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2023/071607 | Jan 2023 | WO |
| Child | 19090455 | US |
