Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries, the single battery comprises a shell, the shell comprises a first shell, a second shell and a plurality of separators, the first shell is provided with a mounting cavity, the second shell is arranged on the outer side of the first shell in a surrounding mode, the second shell and the first shell define a containing cavity, and the separators are located in the containing cavity; the plurality of separators are respectively connected with the first shell and the second shell, are arranged around the first shell at intervals, and extend along the length direction of the shell. A plurality of sub-cavities surrounding a pole group are arranged in a shell, a phase change structure is arranged in each sub-cavity, and if the temperature of the pole group is increased or the external environment temperature is too high, the phase change structures can absorb heat, so that the temperature of the battery is reduced to a certain extent, and when the external environment temperature is too low, the phase change structures can absorb the heat. The phase change structure can release heat, so that the pole group is kept at a certain temperature, and the temperature of the pole group is within a proper application range, thereby ensuring the normal work of the battery.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a single battery and a battery pack. Background Art

[0002] Single batteries are widely used in various electronic devices, which can provide the required electrical energy for the devices. And due to their independence, they can be replaced or charged as needed. However, during the use of a single battery, if the temperature of the battery itself or its surrounding environment is too high or too low, it may affect its normal use. Summary of the Invention

[0003] Object of the Invention: The embodiments of this application provide a single battery, aiming to overcome the technical problem that the normal use of the battery will be affected if the temperature of the battery itself or its surrounding environment is too high or too low; another object of the embodiments of this application is to provide a battery pack.

[0004] Technical Solution: A single battery according to the embodiments of this application includes:

[0005] A housing, including a first shell, a second shell and a plurality of partition members. The first shell has an installation cavity. The second shell is disposed around the outside of the first shell and encloses a receiving cavity with the first shell. A plurality of the partition members are located in the receiving cavity and are respectively connected to the first shell and the second shell. The plurality of partition members are arranged at intervals around the first shell and extend along the length direction of the housing to divide the receiving cavity into a plurality of sub-cavities;

[0006] A pole group, disposed in the installation cavity;

[0007] A phase change structure, disposed in the sub-cavities, and the phase change structure is configured to absorb heat or release heat;

[0008] The single battery satisfies: 50% ≤ S1 / S2 ≤ 90%;

[0009] Wherein, S1 is the total area of the positive projections of the plurality of sub-cavities on a plane perpendicular to the length direction, and S2 is the total area of the positive projection of the housing on a plane perpendicular to the length direction.

[0010] In some embodiments, the single battery satisfies: 50% ≤ V1 / V2 ≤ 95%;

[0011] Wherein, V1 is the total volume of the phase change structure, and V2 is the total volume of the plurality of sub-cavities.

[0012] In some embodiments, the single battery satisfies: 0.5 mm ≤ H1 ≤ 3 mm;

[0013] Among them, H1 is the thickness dimension of the sub-cavity.

[0014] In some embodiments, the single cell includes:

[0015] A package, at least partially disposed in the accommodation cavity, and respectively connected to the first housing and the second housing, for sealing the opening of the accommodation cavity.

[0016] In some embodiments, the package includes a plurality of spaced-apart packaging units, each of the packaging units is located in one of the sub-cavities, and is respectively connected to the first housing, the second housing and the partition, for sealing the opening of the sub-cavity.

[0017] In some embodiments, the packaging unit includes:

[0018] A first fixing portion, located in the sub-cavity, and respectively connected to the first housing, the second housing and the corresponding partition, the first fixing portion has a limiting groove;

[0019] A first sealing portion, partially embedded in the limiting groove, and disposed around the first fixing portion, the first sealing portion is respectively connected to the first fixing portion, the first housing, the second housing and the corresponding partition, for sealing the sub-cavity.

[0020] In some embodiments, the packaging unit includes:

[0021] A second fixing portion, located in the sub-cavity, and respectively connected to the first housing, the second housing and the corresponding partition;

[0022] A second sealing portion, connected to one side of the second fixing portion facing the phase change structure, the second sealing portion is respectively connected to the second fixing portion, the first housing, the second housing and the corresponding partition, for sealing the sub-cavity, the second sealing portion is a flexible material member, and the inside is a hollow structure.

[0023] In some embodiments, the single cell includes:

[0024] A cover plate assembly, covering and sealing the installation cavity, and connected to the first housing and the second housing; the cover plate assembly includes:

[0025] A main body portion, at least partially disposed in the installation cavity;

[0026] An overlapping portion, located outside the installation cavity, and connected to the main body portion, the overlapping portion is disposed around the main body portion, and the overlapping portion is connected to one side of the package facing away from the phase change structure.

[0027] In some embodiments, the cover plate assembly further includes:

[0028] A sealing ring, located in the installation cavity and arranged around the main body portion, and the sealing ring is sealingly connected between the main body portion and the first housing.

[0029] A battery pack includes the single cell described in any one of the above.

[0030] Beneficial effects: The single cell of the embodiment of the present application includes: a housing, including a first housing, a second housing, and a plurality of partition members. The first housing has an installation cavity. The second housing is arranged around the outside of the first housing and encloses a containing cavity with the first housing. The plurality of partition members are located in the containing cavity and are respectively connected to the first housing and the second housing. The plurality of partition members are arranged at intervals around the first housing and extend along the length direction of the housing to divide the containing cavity into a plurality of sub-cavities; a pole group, arranged in the installation cavity; a phase change structure, arranged in the sub-cavities, and the phase change structure is configured to absorb heat or release heat; the single cell satisfies: 50% ≤ S1 / S2 ≤ 90%; where S1 is the total projected area of the plurality of sub-cavities on a plane perpendicular to the length direction, and S2 is the total projected area of the housing on a plane perpendicular to the length direction. A plurality of sub-cavities surrounding the pole group are arranged inside the housing, and a phase change structure is arranged inside each sub-cavity. If the temperature of the pole group rises or the external ambient temperature is too high, the phase change structure can absorb heat, thereby reducing the temperature of the battery to a certain extent. When the external ambient temperature is too low, the phase change structure can release heat, so that the pole group maintains a certain temperature and its temperature is within a suitable range for use, thereby ensuring the normal operation of the battery. When the ratio of the projected area of the sub-cavity on a plane perpendicular to the length direction of the housing to the total projected area of the housing on a plane perpendicular to the length direction is within the above range, the phase change structure can be quickly injected into each sub-cavity, reducing the difficulty of setting the phase change structure. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is an exploded structural schematic diagram of the single cell of the embodiment of the present application;

[0033] Figure 2 It is a partial perspective view of the housing of the embodiment of the present application, where no partition member is provided in the containing cavity;

[0034] Figure 3 Is a partial perspective view of the housing of the embodiment of the present application, wherein a partition member is provided in the accommodation cavity;

[0035] Figure 4 Is a perspective view of multiple encapsulation units of the embodiment of the present application;

[0036] Figure 5 Is a side sectional view of the housing of the embodiment of the present application;

[0037] Figure 6 Is a front sectional view of the housing of the embodiment of the present application, wherein the accommodation cavity has an opening at only one end;

[0038] Figure 7 Is a front sectional view of the housing of the embodiment of the present application, wherein the accommodation cavity has openings at both ends;

[0039] Figure 8 Is a partial sectional view of one end of the housing of the embodiment of the present application;

[0040] Figure 9 Is for the embodiment of the present application Figure 8 A partial enlarged view of area A therein;

[0041] Figure 10 Is a schematic structural view of the second fixing part and the second sealing part of the embodiment of the present application;

[0042] Figure 11 Is a partial sectional view of the connection between the cover plate assembly and the housing of the embodiment of the present application;

[0043] Reference numerals: 10 - housing; 11 - first housing; 111 - installation cavity; 12 - second housing; 13 - partition member; 14 - accommodation cavity; 141 - sub - cavity; 20 - pole group; 30 - phase change structure; 40 - encapsulation member; 41 - encapsulation unit; 411 - first fixing part; 4111 - limiting groove; 412 - first sealing part; 413 - second fixing part; 414 - second sealing part; 50 - cover plate assembly; 51 - main body part; 52 - overlapping part; 53 - sealing ring; X - length direction. Detailed implementation manners

[0044] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0045] In the description of the present application, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality" is two or more, and "at least one" means one, two, or more, unless otherwise specifically defined.

[0046] A single cell refers to an independent battery unit, which is the basic component of a battery. A single cell usually consists of an electrochemical reaction unit and can be used alone or combined with other single cells to form a battery pack. A single cell can be non-rechargeable or rechargeable. Non-rechargeable single cells are usually called disposable batteries and need to be replaced once the electrical energy is exhausted. Common disposable single cells include alkaline batteries (such as alkaline zinc-carbon batteries) and lithium batteries (such as lithium-ion batteries). Rechargeable single cells can restore electrical energy through reverse electrochemical reactions and can be used multiple times. Common rechargeable single cells include nickel-cadmium batteries (Ni-Cd), nickel-metal hydride batteries (Ni-MH), and lithium-ion batteries (Li-ion).

[0047] During the use of a single cell, if the usage time is too long, the temperature will increase. If the temperature of the surrounding environment is too high, it will cause the temperature of the single cell to rise. If the temperature of the surrounding environment is too low, it will cause the temperature of the single cell to drop. And whether the temperature of the single cell is too high or too low may affect its normal use. When the temperature is too high, it will cause the internal chemical reaction of the single cell to accelerate, increasing the self-discharge rate, thereby reducing the capacity of the single cell, and the electrical energy of the single cell is consumed faster. At the same time, it will also shorten the service life of the single cell and increase the risk of thermal runaway of the single cell. When the temperature is too low, it will also reduce the capacity of the single cell, and at the same time increase the internal resistance of the single cell, limiting the discharge and charge rates of the single cell and reducing the rate of the internal chemical reaction of the single cell.

[0048] In view of this, the embodiments of the present application provide a single cell to overcome at least one of the above technical problems.

[0049] Please refer to Figure 1 、 Figure 2 and Figure 3 , in the embodiments of the present application, the single cell includes a housing 10, a pole group 20, and a phase change structure 30.

[0050] The housing 10 includes a first housing 11, a second housing 12, and a plurality of partition members 13. The first housing 11 has an installation cavity 111. The second housing 12 is disposed around the outside of the first housing 11 and encloses a receiving cavity 14 with the first housing 11. The plurality of partition members 13 are located in the receiving cavity 14 and are respectively connected to the first housing 11 and the second housing 12. The plurality of partition members 13 are arranged at intervals around the first housing 11 and extend along the length direction X of the housing 10 to divide the receiving cavity 14 into a plurality of sub-cavities 141. The electrode group 20 is disposed in the installation cavity 111. The phase change structure 30 is disposed in the sub-cavity 141, and the phase change structure 30 is configured to absorb heat or release heat. It can be understood that the housing 10 can be configured as a sandwich structure. By disposing the smaller-sized first housing 11 inside the larger-sized second housing 12, an accommodating cavity 14 can be enclosed therebetween, and the accommodating cavity 14 is disposed around the first housing 11. Since the heat conduction effect of air is lower than that of metal (the first housing 11 and the second housing 12 are generally metal structures), when the external environmental temperature is too high or too low, this sandwich structure of the housing 10 can play a certain heat preservation role, reducing the influence of the external environmental temperature on the electrode group 20 inside the first housing 11 and preventing the temperature of the electrode group 20 from rising or falling rapidly.

[0051] The receiving cavity 14 is divided into a plurality of sub-cavities 141 disposed around the first housing 11 by a plurality of partition members 13, and then a phase change structure 30 is disposed inside each sub-cavity 141. By changing the state of the phase change structure 30, heat can be released or absorbed. The phase change structure 30 can be paraffin, fatty acids, polyolefins, alcohols, etc. When the temperature of the battery is too high or the temperature of the surrounding environment is too high, the phase change structure 30 changes from a solid state to a liquid state or from a liquid state to a gaseous state (phase transformation), absorbs heat, and thus cools the battery to prevent the temperature of the battery from rising too fast. When the surrounding environmental temperature is low, the phase change structure 30 changes from a liquid state to a solid state or from a gaseous state to a liquid state (phase transformation), releases heat, and thus increases the temperature of the battery. The heat conduction effect of the phase change structure 30 after becoming a solid state is relatively poor compared to metal, and it can also block the influence of low temperature to a certain extent when the external environmental temperature is low, playing a heat preservation role for the battery. Therefore, by arranging the phase change structure 30, it can further play a certain heat preservation role for the battery, keep its temperature within a suitable range, thus ensuring the normal operation of the battery and preventing the temperature of the battery from rising or falling rapidly, which affects the normal use of the battery.

[0052] Under certain temperature conditions, the phase change structure 30 will change state and become a liquid with strong free ability, or even a gas state, and its position cannot be fixed. Under the influence of gravity or other factors, the phase change structure 30 in the liquid or gas state may be free to a certain position of the accommodating cavity 14, and it cannot absorb and release the temperature at other positions on the battery, which will make the temperature distribution on the battery uneven, and the overall temperature of the battery cannot be maintained within a suitable range, which is not conducive to the use of the battery. Moreover, when the phase change structure 30 becomes solid again, it may also be formed at a certain position of the accommodating cavity 14, and it cannot cover the surface of the first shell 11, and cannot play a good insulation effect. By dividing the accommodating cavity 14 into a plurality of sub-cavities 141 arranged around the first shell 11, each sub-cavity 141 is provided with a phase change structure 30 inside. Since the space of the sub-cavity 141 is small, the range of movement of the phase change structure 30 can be limited, so that the phase change structure 30 is arranged more evenly. Even if its state changes, the free range will not be too large, and it can still absorb or release heat to the battery structure within the corresponding range. The sub-cavity 141 is arranged around the first shell 11, and the phase change structure 30 inside the sub-cavity 141 is also arranged in the first shell 11, so that the temperature distribution on the battery is more uniform (the more sub-cavities 141, the smaller the space, when the battery is kept warm, the more uniform the temperature distribution on the battery). Even if the phase change structure 30 changes from a free state to a solid state, since its free range is limited, most of the phase change structure 30 after becoming solid can still cover the surface of the first shell 11 in the sub-cavity 141, so that when the temperature of the external environment is low, it can have a better insulation effect on the battery.

[0053] The single cell satisfies: 50% ≤ S1 / S2 ≤ 90%; where S1 is the total area of the positive projections of multiple sub-chambers 141 on a plane perpendicular to the length direction X of the outer shell 10, and S2 is the total area of the positive projection of the outer shell 10 on a plane perpendicular to the length direction X. It can be understood that S1 / S2 is generally in the range of 50% to 90%, and S1 / S2 can be any value among 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or the range value between any two values. S1 and S2 are measured by tools such as calipers or 3D scanners. Using calipers, the corresponding dimensions of the cross-section of the sub-chamber 141 and the corresponding dimensions of the cross-section of the outer shell can be directly measured, and then the cross-sectional area of the sub-chamber 141 and the cross-sectional area of the outer shell can be obtained through calculation, that is, the positive projection area of the sub-chamber 141 on a plane perpendicular to the length direction X of the outer shell 10 and the total area of the positive projection of the outer shell 10 on a plane perpendicular to the length direction X. It can also be measured by a 3D scanner. The 3D scanner can obtain the 3D data of the cross-section of the corresponding sub-chamber 141 and the 3D data of the cross-section of the outer shell, and then the cross-sectional area of the sub-chamber 141 and the cross-sectional area of the outer shell can be obtained through calculation. It should be noted that the phase change structure 30 in the embodiment of the present application is injected into the interior of the sub-chamber 141 in a liquid state. During specific testing, a corresponding injection device, such as a syringe, can be used to inject the phase change structure 30 into the interior of the sub-chamber 141, and the volume of the phase change structure 30 injected into all sub-chambers 141 per minute is detected. It is stipulated that at least 30 ml of the liquid phase change structure 30 is injected per minute, which means that the cross-sectional opening area of the sub-chamber 141 is qualified, otherwise it is unqualified. The test results of the examples and comparative examples are shown in Table 1 below:

[0054]

[0055] As can be seen from the above table, when S1 / S2 is in the range of 50% to 90%, for the phase change structure 30 injected into all sub-chambers 141 by the device, the injection rate of the phase change structure 30 is above 30 ml / min. When S1 / S2 is 50%, the injection rate of the phase change structure 30 is 30 ml / min. When S1 / S2 is 90%, the injection rate of the phase change structure 30 is 71 ml / min. When S1 / S2 is 95%, the injection rate of the phase change structure 30 is 77 ml / min. However, when S1 / S2 is 90%, the thickness H1 of the sub-chamber 141 is 3 mm, and when S1 / S2 is 95%, the thickness H1 of the sub-chamber 141 is 5 mm, with a relatively large change range. Moreover, when S1 / S2 is 95%, the thickness H1 of the sub-chamber 141 is also relatively large, which is not conducive to improving the energy density of the battery. Therefore, when S1 / S2 is in the range of 50% to 90%, it can meet the injection requirements of the phase change structure 30, ensure the processing efficiency of the battery, and also enable the battery to have a relatively high energy density.

[0056] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 5 , in combination with the above embodiments, in some embodiments, the single cell satisfies: 50% ≤ V1 / V2 ≤ 95%; wherein, V1 is the total volume of the phase change structure 30, and V2 is the total volume of the plurality of sub-chambers 141. It can be understood that when the ratio of the volume V1 of the phase change structure 30 to the total volume V2 of the sub-chambers 141 is in the range of 50% to 95%, during the process from the start to the end of the life cycle of the battery, the temperature of the internal electrode group 20 can be maintained within the range of 10°C to 45°C, and the temperature of the electrode group 20 is relatively stable, which can improve the safety during the use of the battery. Among them, the total volume V1 of the phase change structure 30 can be measured by a graduated cylinder (in this embodiment, the phase change structure 30 is liquid), or can be obtained through simple calculation. The total volume V2 of the plurality of sub-chambers 141 can be measured by devices such as a caliper or a three-dimensional measuring instrument, and then can be obtained through certain calculations. During specific testing, a corresponding injection device, such as a syringe, can be used to inject the phase change structure 30 into the internal of the sub-chambers 141 of 500 battery samples, and observe whether the phase change structure 30 overflows from the sub-chambers 141. During the injection of the phase change structure 30, the ratio of the number of battery samples with the phase change structure 30 overflowing from the sub-chambers 141 to the total number of samples is the defective rate of the phase change material. If the defective rate of the phase change material is less than or equal to 1%, it is qualified, otherwise it is unqualified. The test results are shown in Table 2 below:

[0057]

[0058]

[0059] As can be seen from Table 2, when the ratio of the total volume V1 of the phase change structure 30 to the total volume V2 of the plurality of sub-chambers 141 is in the range of 50% to 95%, the defective rate of the phase change material is relatively low, all below 1%. During the process from the start to the end of the life cycle of the battery, the temperature of the internal electrode group 20 is maintained within the range of 10°C to 45°C, and the temperature of the electrode group 20 is relatively stable, and the battery operates in a better temperature range. When the value of V1 / V2 is less than 50%, the total volume V1 of the phase change structure 30 is relatively small, and the heat absorption and cooling effect on the battery electrode group 20 is not obvious, and the heat preservation effect is poor. When the value of V1 / V2 is greater than 95%, the defective rate of the phase change material is 5.23%, which is greater than 1%, and the defective rate of the phase change material is relatively high, which will increase the cost and is not recommended for use.

[0060] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 5, in combination with the above embodiments, in some embodiments, the single cell satisfies: 0.5 mm ≤ H1 ≤ 3 mm; wherein, H1 is the thickness dimension of the sub-cavity 141. It can be understood that the thickness dimension of the sub-cavity 141 is the dimension in the wall thickness direction of the outer shell 10. As can be seen from Table 1 above, when H1 is in the range of 0.5 mm to 3 mm, the phase change structure 30 can be smoothly injected into the sub-cavity 141, and at the same time, the housing of the battery is convenient to form, and the yield rate of housing forming is relatively high. When the value of H1 is less than 0.5 mm, with the total volume of the battery remaining unchanged, the opening area of the sub-cavity 141 will be relatively small, making it difficult to inject the phase change structure 30, and also making it difficult to form the housing of the battery, resulting in a decrease in the yield rate of housing forming, and it is not recommended to use. When the value of H1 is greater than 3 mm, with the total volume of the battery remaining unchanged, the opening area of the sub-cavity 141 will be relatively large, and it is relatively easy to inject the phase change structure 30 into the sub-cavity 141. However, the thickness dimension H1 of the sub-cavity 141 is relatively large, which is not conducive to improving the volume energy density of the battery, and it is not recommended to use.

[0061] Please refer to Figure 1 , Figure 6 and Figure 7 , in combination with the above embodiments, in some embodiments, the single cell includes a packaging member 40. The packaging member 40 is at least partially disposed in the accommodation cavity 14 and is respectively connected to the first housing 11 and the second housing 12 for sealing the opening of the accommodation cavity 14. It can be understood that the opening of the accommodation cavity 14 can be sealed by the packaging member 40, which actually seals the opening of each sub-cavity 141, thereby preventing the phase change structure 30 inside each sub-cavity 141 from leaking out from the opening of the sub-cavity 141 after changing from solid to liquid, and improving the sealing performance of the sub-cavity 141. When setting the sub-cavity 141, one end of the sub-cavity 141 in the length direction X can be opened (such as Figure 6 ), and this setting method only needs to seal one end of the sub-cavity 141, which can save the material of the packaging member 40 and reduce the cost. It is also possible to provide openings at both ends of the sub-cavity 141 in the length direction X (such as Figure 7 ), and this setting method can directly penetrate the outer shell 10 along the length direction X during processing, thereby reducing the processing difficulty. At the same time, when injecting the liquid phase change structure 30, it can be injected from both ends and can be selected according to needs, with a certain anti-fooling effect.

[0062] Please refer to Figure 1 , Figure 3 and Figure 4, in combination with the above embodiments, in some embodiments, the encapsulation member 40 includes a plurality of encapsulation units 41 arranged at intervals. Each encapsulation unit 41 is located in a sub-cavity 141 and is respectively connected to the first housing 11, the second housing 12, and the partition member 13 for sealing the opening of the sub-cavity 141. It can be understood that the plurality of encapsulation units 41 on the encapsulation member 40 can be respectively embedded into the openings of each sub-cavity 141, thereby realizing the sealing of the sub-cavity 141. The cross-sectional shape of the encapsulation unit 41 is the same as that of the corresponding sub-cavity 141. The encapsulation unit 41 can be fixed by interference fit, snap connection, welding, etc., which can improve the sealing effect of the sub-cavity 141.

[0063] Please refer to Figure 8 and Figure 9 , in combination with the above embodiments, in some embodiments, the encapsulation unit 41 includes a first fixing portion 411 and a first sealing portion 412.

[0064] The first fixing portion 411 is located in the sub-cavity 141 and is respectively connected to the first housing 11, the second housing 12, and the corresponding partition member 13. The first fixing portion 411 has a limiting groove 4111. The first sealing portion 412 is partially embedded in the limiting groove 4111 and is arranged around the first fixing portion 411. The first sealing portion 412 is respectively connected to the first fixing portion 411, the first housing 11, the second housing 12, and the corresponding partition member 13 for sealing the sub-cavity 141. It can be understood that the encapsulation unit 41 can be composed of the first fixing portion 411 and the first sealing portion 412. The first fixing portion 411 can be embedded into the interior of the corresponding sub-cavity 141. The first fixing portion 411 and the sub-cavity 141 can be connected by interference fit. This connection method is simpler than welding and snap connection. No other structures need to be provided on the battery, and the battery will not be damaged during connection. At the same time, the first sealing portion 412 is sleeved in the limiting groove 4111 on the first fixing portion 411, which is equivalent to the first sealing portion 412 being arranged around the first fixing portion 411. The limiting groove 4111 can play a role in limiting the first sealing portion 412 to prevent the installation position of the first sealing portion 412 from shifting and changing randomly. The first sealing portion 412 is in close contact with the first fixing portion 411, the first housing 11, the second housing 12, and the corresponding partition member 13 respectively, which can further improve the sealing effect of the sub-cavity 141. The first sealing portion 412 can be a component made of materials such as silica gel and rubber.

[0065] Please refer to Figure 10 , in combination with the above embodiments, in some embodiments, the encapsulation unit 41 includes a second fixing portion 413 and a second sealing portion 414.

[0066] The second fixing part 413 is located inside the sub-cavity 141 and is connected to the first housing 11, the second housing 12, and the corresponding partition 13 respectively. The second sealing part 414 is connected to the side of the second fixing part 413 facing the phase change structure 30. The second sealing part 414 is connected to the second fixing part 413, the first housing 11, the second housing 12, and the corresponding partition 13 respectively, and is used to seal the sub-cavity 141. The second sealing part 414 is a flexible material component and has a hollow structure inside. It can be understood that the encapsulation unit 41 can be composed of the second fixing part 413 and the second sealing part 414. The second fixing part 413 can be embedded inside the corresponding sub-cavity 141. The second fixing part 413 and the sub-cavity 141 can be connected by an interference fit. Compared with connection methods such as welding and snap connection, this connection method is simpler, does not require other structures to be provided on the battery, and will not damage the battery during connection. The second sealing part 414 is fixedly connected to the side of the second fixing part 413 facing the phase change structure 30. When the phase change structure 30 changes from a solid state to a liquid state, its volume generally becomes larger. If the volume of the phase change structure 30 filled inside the sub-cavity 141 is large, after becoming liquid, the volume will further increase, which may squeeze the second sealing part 414. Since the second sealing part 414 is a flexible material component and has a hollow structure inside and has good deformation ability, when the liquid phase change structure 30 squeezes one side of the second sealing part 414, the second sealing part 414 will deform, the dimension in the length direction X decreases, and the dimension in the direction perpendicular to the length direction X has a tendency to increase. However, due to the blocking effect of the second fixing part 413, the first housing 11, the second housing 12, and the corresponding partition 13, the dimension of the second sealing part 414 in the direction perpendicular to the length direction X cannot increase, but it will increase the extrusion force of the second sealing part 414 on the first housing 11, the second housing 12, and the corresponding partition 13, thereby increasing the friction force between the second sealing part 414 and the first housing 11, the second housing 12, and the corresponding partition 13, improving the overall stability of the encapsulation unit 41, and preventing the encapsulation unit 41 from being extruded out of the inside of the sub-cavity 141 after the volume of the phase change structure 30 becomes larger. The second sealing part 414 can be made of materials such as silica gel and rubber.

[0067] Meanwhile, the second sealing portion 414 has a certain ability to shrink and deform, and the deformation ability of the second sealing portion 414 is greater than that of the first housing 11, the second housing 12, and the partition member 13. After the volume of the phase change structure 30 increases, it can occupy a part of the original position space of the second sealing portion 414, thereby reducing the extrusion force of the phase change structure 30 with an increased volume on the first housing 11, the second housing 12, and the partition member 13. During the process of the phase change structure 30 changing from a solid state to a liquid state, it can play a certain protective role for the first housing 11, the second housing 12, and the partition member 13, preventing the first housing 11, the second housing 12, and the partition member 13 from deforming and being damaged.

[0068] Please refer to Figure 11 , in combination with the above embodiments, in some embodiments, the single cell includes a cover plate assembly 50. The cover plate assembly 50 covers and seals the installation cavity 111 and is connected to the first housing 11 and the second housing 12. The cover plate assembly 50 includes a main body portion 51 and a lapping portion 52. The main body portion 51 is at least partially disposed in the installation cavity 111. The lapping portion 52 is located outside the installation cavity 111 and is connected to the main body portion 51. The lapping portion 52 surrounds the main body portion 51 and is connected to the side of the encapsulation member 40 facing away from the phase change structure 30. It can be understood that by disposing the lapping portion 52 on the cover plate assembly 50 on the side of the encapsulation member 40 facing away from the phase change structure 30, the lapping portion 52 can be fixedly connected to the first housing 11 and the second housing 12. During the process of the phase change structure 30 changing from a solid state to a liquid state, the volume increases and it will push the encapsulation member 40, while the lapping portion 52 can play a certain blocking role for the encapsulation member 40, thereby offsetting the thrust of the phase change structure 30 on the encapsulation member 40, preventing the encapsulation member 40 from being pushed out of the sub-cavity 141 by the phase change structure 30 with an increased volume, improving the stability of the encapsulation member 40, and ensuring its sealing effect on the sub-cavity 141.

[0069] Please refer to Figure 11 , in combination with the above embodiments, in some embodiments, the cover plate assembly 50 further includes a sealing ring 53. The sealing ring 53 is located in the installation cavity 111 and surrounds the main body portion 51. The sealing ring 53 is sealingly connected between the main body portion 51 and the first housing 11. It can be understood that a sealing ring 53 can be disposed between the main body portion 51 and the first housing 11, which can improve the sealing performance between the main body portion 51 and the first housing 11, prevent the electrolyte in the installation cavity 111 from passing through the gap between the two and leaking to the position of the encapsulation member 40, causing corrosion to the encapsulation member 40, and improving the safety of the encapsulation member 40.

[0070] A battery pack for storing and releasing electrical energy, comprising a box body and a plurality of the above-mentioned single cells, and the plurality of single cells are accommodated in the box body. Among them, the battery pack can be a charge-discharge structure composed of a plurality of battery cells, such as a battery module, a battery cluster, a battery stack, a battery tower, a battery array, etc. The single cell includes but is not limited to a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present disclosure do not limit this.

[0071] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0072] The above has introduced in detail the single cell and the battery pack provided by the embodiments of the present application, and specific examples have been used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A housing, comprising a first housing, a second housing and a plurality of partitions, wherein the first housing has a mounting cavity, the second housing is disposed around the outside of the first housing and is enclosed with the first housing to form a receiving cavity, a plurality of partitions are located in the receiving cavity and are respectively connected to the first housing and the second housing, the plurality of partitions are arranged around the first housing at intervals and extend along the length direction of the housing to divide the receiving cavity into a plurality of sub-cavities; A pole group, arranged in the mounting cavity; A phase change structure is disposed in the sub-cavity, and the phase change structure is configured to absorb heat or release heat; The single cell meets the following requirements: 50%≤S1 / S2≤90%; Wherein, S1 is the total area of ​​the orthographic projections of the plurality of sub-cavities on a plane perpendicular to the length direction, and S2 is the total area of ​​the orthographic projections of the shell on a plane perpendicular to the length direction.

2. The single cell according to claim 1, characterized in that: The single cell battery satisfies: 50%≤V1 / V2≤95%; Wherein, V1 is the total volume of the phase change structure, and V2 is the total volume of the plurality of sub-cavities.

3. The single cell according to claim 1, characterized in that: The single cell meets the following requirements: 0.5mm≤H1≤3mm; Wherein, H1 is the thickness dimension of the sub-cavity.

4. The single cell according to claim 1, characterized in that: The single cell battery comprises: The packaging component is at least partially disposed in the accommodating cavity and is respectively connected to the first shell and the second shell, and is used to seal the opening of the accommodating cavity.

5. The single cell according to claim 4, characterized in that: The packaging member includes a plurality of packaging units arranged at intervals, each of which is located in one of the sub-cavities and is respectively connected to the first shell, the second shell and the partition member to seal the opening of the sub-cavity.

6. The single cell according to claim 5, characterized in that: The packaging unit comprises: A first fixing portion, located in the sub-cavity and connected to the first shell, the second shell and the corresponding partition respectively, and the first fixing portion has a limiting groove; The first sealing portion is partially embedded in the limiting groove and is arranged around the first fixing portion. The first sealing portion is respectively connected to the first fixing portion, the first shell, the second shell and the corresponding partition to seal the sub-cavity.

7. The single cell according to claim 5, characterized in that: The packaging unit comprises: A second fixing portion is located in the sub-cavity and is respectively connected to the first shell, the second shell and the corresponding partition; The second sealing part is connected to the side of the second fixed part facing the phase change structure. The second sealing part is respectively connected to the second fixed part, the first shell, the second shell and the corresponding partition to seal the sub-cavity. The second sealing part is a flexible material component and has a hollow structure inside.

8. The single cell according to claim 4, characterized in that: The single cell battery comprises: A cover plate assembly, covering the installation cavity and connected to the first shell and the second shell; the cover plate assembly includes: A main body, at least partially disposed in the mounting cavity; The overlapping portion is located outside the installation cavity and connected to the main body. The overlapping portion is arranged around the main body and connected to a side of the packaging component away from the phase change structure.

9. The single cell according to claim 8, characterized in that: The cover plate assembly also includes: The sealing ring is located in the installation cavity and is arranged around the main body. The sealing ring is sealingly connected between the main body and the first shell.

10. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 9.

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