Battery monomer, battery and electric device

Abstract

The utility model relates to a battery monomer, a battery and a power utilization device, and the battery monomer comprises a shell which is provided with a containing cavity, and the containing cavity is provided with a first wall; the electrode assembly is arranged in the accommodating cavity; the fixing piece is arranged between the electrode assembly and the first wall and supported on the electrode assembly, and a liquid passing channel penetrating in the thickness direction of the first wall is formed in the fixing piece; the fixing piece comprises a supporting face making contact with the electrode assembly, and the area of the supporting face accounts for at least 50% of the surface area of the electrode assembly making contact with the supporting face. According to the application, the fixing piece is arranged to play a supporting role between the electrode assembly and the first wall, so that expansion deformation of the electrode assembly can be limited, and the probability that the electrode assembly shakes in the shell can also be reduced; in addition, the electrolyte can smoothly flow through the liquid passing channel in the fixing piece, a sufficient containing space is provided for the electrolyte, and the probability that the hydraulic pressure in the shell is too large or the electrolyte overflows is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] In the structure of a battery cell, the electrode assembly is placed inside the shell, and the shell is filled with electrolyte so that the electrolyte can fully penetrate the electrode assembly, allowing the electrode assembly to undergo electrochemical reactions smoothly.

[0003] The electrode assembly will expand and deform during the electrochemical reaction. The expansion deformation will not only affect the performance of the electrode assembly itself, but also squeeze the electrolyte, which may easily lead to problems such as excessive hydraulic pressure inside the shell or electrolyte overflow. Utility Model Content

[0004] Based on this, it is necessary to provide a battery cell, battery and electrical device to address the problem that expansion deformation of the electrode assembly not only affects the performance of the electrode assembly itself, but also squeezes the electrolyte, easily leading to excessive hydraulic pressure inside the shell or electrolyte overflow.

[0005] In the first aspect, the present application provides a battery cell, comprising a shell, an electrode assembly and a fixing member, wherein the shell has a accommodating cavity, the accommodating cavity has a first wall; the electrode assembly is arranged in the accommodating cavity; the fixing member is arranged between the electrode assembly and the first wall and supported by the electrode assembly, and a liquid passage is provided on the fixing member and passes through the fixing member along the thickness direction of the first wall; wherein the fixing member includes a supporting surface in contact with the electrode assembly, and the area of ​​the supporting surface accounts for at least 50% of the surface area of ​​the electrode assembly in contact with it.

[0006] The provision of a fixing not only limits the expansion and deformation of the electrode assembly but also reduces the probability of the electrode assembly shaking inside the housing and causing damage to the electrode assembly. Furthermore, since the fixing is provided with a liquid flow channel, the electrolyte in the receiving chamber can flow smoothly through the liquid flow channel. This provides more ample storage space for the electrolyte, reduces the probability of problems such as excessive hydraulic pressure or electrolyte overflow inside the housing, and ensures more stable performance of the battery cell.

[0007] In some embodiments, the support surface has an area of ​​70% to 100% of the surface area of ​​the electrode assembly in contact therewith.

[0008] Through the above structure, the contact area between the supporting surface and the surface of the corresponding electrode assembly is increased, further improving the supporting effect of the fixing member on the electrode assembly.

[0009] In some embodiments, the liquid passage includes a main flow channel extending through the thickness direction of the first wall, and the volume of the main flow channel accounts for at least 50% of the volume of the fixing element.

[0010] In some embodiments, the liquid passage further includes a branch channel, which is arranged to penetrate the fixing member along a direction intersecting with the thickness direction of the first wall, and the total volume of the main channel and the branch channel accounts for at least 80% of the volume of the fixing member.

[0011] In some embodiments, in a direction intersecting the support surface, a ratio between a height of the fixing member and a height of the housing ranges from 0.03 to 0.4.

[0012] By setting the ratio between the height of the fixing member and the height of the shell to the above range, the volume energy density of the battery cell can be effectively improved while improving the flow performance of the electrolyte inside the shell and in the liquid flow channel.

[0013] In some embodiments, in a direction intersecting the support surface, a ratio of a height of the fixing member to a height of the housing ranges from 0.03 to 0.25.

[0014] In this way, the rebound ratio of the metal negative electrode system can be further optimized, the volume energy density advantage of the battery cell can be expanded to a greater extent, and the internal structure stability and reliability can be further improved.

[0015] In some embodiments, the ratio of the volume of the fixing member to the volume of the accommodating cavity ranges from 5% to 40%.

[0016] When the ratio of the volume of the fixing member to the volume of the accommodating chamber is set within the above range, it not only meets the basic electrolyte circulation space and reduces the probability of the explosion-proof valve opening due to excessive hydraulic pressure during full charging, but also meets the rebound ratio of different metal negative electrode systems, thereby improving the volumetric energy density advantage of the battery cell.

[0017] In some embodiments, the ratio of the volume of the fixing member to the volume of the accommodating cavity ranges from 10% to 25%.

[0018] The above range can optimize the rebound ratio of the metal negative electrode system and further expand the volume energy density advantage of the battery cell 100.

[0019] In some embodiments, the shell includes a body and a top cover, and the top cover sealing cover is arranged on the opening of the body, and the two together enclose to form a accommodating cavity; wherein the first wall is a side surface of the top cover facing the interior of the accommodating cavity.

[0020] Through the above structure, during the assembly process, the electrode assembly is first placed in the accommodating cavity, then the fixing part is placed on the side surface of the electrode assembly facing the opening, and finally the top cover sealing cover is placed at the opening, so that the battery cell can be assembled, which is easy to operate.

[0021] In some embodiments, an electrode terminal is provided on the top cover, and a first electrode tab and a second electrode tab are formed on the electrode assembly. The first electrode tab and the second electrode tab are both arranged toward the top cover and are electrically connected to the electrode terminal through the liquid channel.

[0022] Through this structure, the first and second tabs are electrically connected to the electrode terminals on the top cover, enabling smooth energy transfer between the battery cells. Furthermore, the liquid passages on the fixing member not only facilitate electrolyte flow but also allow the first and second tabs to pass through and electrically connect to the electrode terminals.

[0023] In some embodiments, the main body has a first side wall and a second side wall that are oppositely arranged and both intersect with the top cover, and electrode terminals are provided on the first side wall and the second side wall; wherein, the first pole ear and the second pole ear are formed at the opposite ends of the electrode assembly respectively, the first pole ear is arranged toward the first side wall and is electrically connected to the electrode terminal on the first side wall, and the second pole ear is arranged toward the second side wall and is electrically connected to the electrode terminal on the second side wall.

[0024] Through the above structure, the electrode assembly has tabs on both sides, and the first and second tabs can be electrically connected to the electrode terminals via flexible connections. First, when the electrode assembly is placed in the accommodating cavity, the electrolyte level is parallel to the top cover, and the cross-section of the electrode assembly, i.e., the end surface forming the first and second tabs, is perpendicular to the electrolyte level. This allows the electrolyte to better penetrate into the interior of the electrode assembly through the cross-section, allowing for better absorption of the electrolyte. In addition, by placing the first and second tabs toward the first and second side walls, and supporting the fixings between the electrode assembly and the top cover, the support surface and the electrode assembly can be more stably fitted, improving the support effect.

[0025] In some embodiments, a ventilation hole communicating with the accommodating cavity is formed through the top cover, a ventilation component is provided in the ventilation hole, and the ventilation component is configured to achieve one-way ventilation from the inside of the accommodating cavity to the outside.

[0026] In some embodiments, the electrode assembly is a cathode-less electrode assembly.

[0027] With the above structure, the fixing member can provide stable support for the electrode assembly, play a certain limiting role, and reduce the probability of expansion and deformation of the electrode assembly. In addition, the fixing member supports the electrode assembly and can also improve the stability of the electrode assembly in the receiving chamber, reducing the probability of the electrode assembly shifting or shaking during recycling. On the other hand, the liquid channel provided on the fixing member can provide a circulation channel for the electrolyte, providing a larger storage space for the electrolyte, which can effectively improve the problem of excessive hydraulic pressure in the receiving chamber and reduce the probability of electrolyte overflow.

[0028] In a second aspect, the present application also provides a battery comprising the battery cell described above.

[0029] In a third aspect, the present application also provides an electrical device comprising the battery as described above.

[0030] The above-mentioned battery cells, batteries and electrical devices, by arranging fixing parts, play a supporting role between the electrode assembly and the first wall of the corresponding accommodating cavity, so that the electrode assembly can be more stably arranged in the accommodating cavity. In this way, not only the expansion deformation of the electrode assembly can be limited, but also the probability of the electrode assembly shaking inside the shell and causing damage to the electrode assembly can be reduced; in addition, since the liquid channel is opened through the fixing part, the electrolyte in the accommodating cavity can flow smoothly in the accommodating cavity through the liquid channel. In this way, more sufficient accommodating space can be provided for the electrolyte, reducing the probability of problems such as excessive hydraulic pressure or electrolyte overflow inside the shell, making the performance of the battery cell more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of a battery cell according to one or more embodiments.

[0032] Figure 2 FIG. 1 is a top view of a fixing member in a battery cell according to one or more embodiments.

[0033] Figure 3 FIG. 1 is a top view of a fixing member in a battery cell according to one or more embodiments.

[0034] Figure 4 FIG. 1 is a front view of a fixing member in a battery cell according to one or more embodiments.

[0035] Figure 5 FIG. 1 is a left side view of a fixing member in a battery cell according to one or more embodiments.

[0036] Figure 6 is a schematic structural diagram of a battery cell according to one or more embodiments.

[0037] Explanation of the accompanying drawings: 100, battery cell; 10, shell; 20, electrode assembly; 30, fixing part; 11, accommodating cavity; 12, body; 13, top cover; 14, electrode terminal; 15, first side wall; 16, second side wall; 17, air vent; 21, first electrode tab; 22, second electrode tab; 31, liquid passage; 311, mainstream channel; 312, branch channel. DETAILED DESCRIPTION

[0038] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0039] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0040] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0041] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0042] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0043] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0044] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0045] The battery structure generally includes a box and battery cells. The battery cells are placed in the box, so that the box provides a space for the battery cells and provides good protection for the battery cells.

[0046] Among them, the battery cell is the smallest unit that makes up the battery. For a battery cell, it usually includes a shell and an electrode assembly contained inside the shell. The shell is also filled with electrolyte so that the electrolyte fully infiltrates the electrode assembly so that the electrode assembly can smoothly undergo electrochemical reactions.

[0047] The electrode assembly will expand and deform during the electrochemical reaction. The expanded electrode assembly will not only affect its own performance, but also, due to the increase in the volume of the electrode assembly, it will squeeze the electrolyte inside the shell, resulting in excessive hydraulic pressure inside the shell or causing the electrolyte to overflow.

[0048] Furthermore, different types of battery cells experience different changes in expansion deformation. For example, in a battery system without an anode, since the anode current collector lacks active negative material, it cannot retain the electrolyte. This results in poor electrolyte retention in the electrode assembly and a greater rate of volume change.

[0049] In this way, the negative electrode-free battery system will result in a higher probability of the electrolyte being squeezed out of the shell, so more space needs to be provided to meet the changes in the electrolyte level.

[0050] Based on the above considerations, in order to solve the problem that the expansion deformation of the electrode assembly not only affects the performance of the electrode assembly itself, but also squeezes the electrolyte, which easily leads to excessive hydraulic pressure inside the shell or electrolyte overflow, one or more embodiments of the present application provide a battery cell. By setting a fixing part, it plays a supporting role between the electrode assembly and the inner wall of the corresponding accommodating cavity, so that the electrode assembly can be more stably arranged in the accommodating cavity. In this way, not only can the expansion deformation of the electrode assembly be limited, but also the probability of the electrode assembly shaking inside the shell and causing damage to the electrode assembly can be reduced. In addition, since a liquid passage is opened through the fixing part, the electrolyte in the accommodating cavity can flow smoothly in the accommodating cavity through the liquid passage. In this way, more sufficient accommodation space can be provided for the electrolyte, reducing the probability of problems such as excessive hydraulic pressure or electrolyte overflow inside the shell, making the performance of the battery cell more stable.

[0051] It should be noted that the battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or in a hybrid manner via a busbar.

[0052] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. For example, a battery cell assembly can be a battery module, which is a single module formed by arranging and securing multiple battery cells. For example, a battery module can be formed by bundling multiple battery cells using cable ties.

[0053] In some embodiments, the battery may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0054] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0055] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0056] See Figure 1 and Figure 2 An embodiment of the present application provides a battery cell 100, comprising a shell 10, an electrode assembly 20, and a fixing member 30. The shell 10 has a housing 11, the housing 11 has a first wall (not shown in the figure), and the electrode assembly 20 is disposed in the housing 11. The fixing member 30 is disposed between the electrode assembly 20 and the first wall and supported on the electrode assembly 20. The fixing member 30 is provided with a liquid passage 31 that passes through the fixing member 30 along the thickness direction of the first wall. The fixing member 30 includes a supporting surface in contact with the electrode assembly 20, and the area of ​​the supporting surface accounts for at least 50% of the surface area of ​​the electrode assembly 20 in contact therewith.

[0057] It should be noted that the housing 10 is a structure used to house the electrode assembly 20, electrolyte, and other functional structures, and provides a certain degree of protection for the electrode assembly 20 and other structures. The interior of the housing 10 is hollow, forming a housing cavity 11. The electrode assembly 20 is placed in the housing cavity 11, and the housing cavity 11 is filled with electrolyte to ensure that the electrolyte can fully penetrate the electrode assembly 20, allowing the electrode assembly 20 to smoothly undergo electrochemical reactions.

[0058] The electrode assembly 20 refers to the component in the battery cell 100 where the electrochemical reaction actually occurs. The electrode assembly 20 is typically formed by stacking or winding a positive electrode sheet, a separator, and a negative electrode sheet in sequence. The positive and negative electrode sheets typically include a current collector, which is primarily a metal foil. Active material can be coated on the current collector. For example, coating the current collector with a positive active material forms the main body of the positive electrode sheet, while the portion not coated with the active material forms the positive electrode tab. Similarly, coating the current collector with a negative active material forms the main body of the negative electrode sheet, while the portion not coated with the active material forms the negative electrode tab.

[0059] When the active material is coated on the current collector and when the shell 10 is filled with electrolyte, the positive electrode active material and the negative electrode active material are infiltrated with electrolyte, realizing the electrolyte retention function so that the electrolyte can fully infiltrate the electrode assembly 20, so that the electrode assembly 20 can smoothly undergo electrochemical reaction.

[0060] When the electrode assembly 20 undergoes an electrochemical reaction, the electrode assembly 20 will expand and deform. Currently, in order to increase the energy density of the battery cell 100, the space reserved inside the shell 10 is often small so that the electrode assembly 20 can be more fully filled inside the shell 10. However, in this case, when the electrode assembly 20 undergoes expansion and deformation, first, the structure of the electrode assembly 20 after expansion and deformation changes, which will affect the performance of the electrode assembly 20 itself. Secondly, after the electrode assembly 20 expands, it will squeeze the electrolyte inside the shell 10, which can easily lead to excessive hydraulic pressure inside the shell 10, or even cause the electrolyte to overflow, affecting the performance of the battery cell 100.

[0061] Based on this, the present application arranges the electrode assembly 20 in the accommodating cavity 11, forms an installation position between the electrode assembly 20 and the first wall of the accommodating cavity 11, and arranges the fixing member 30 in the installation position. The fixing member 30 can support the electrode assembly 20 and the first wall in the installation position, so that the electrode assembly 20 can be more stably arranged in the accommodating cavity 11.

[0062] Specifically, the first wall may be one of the inner walls of the accommodating cavity 11, that is, the fixing member 30 may be supported between the electrode assembly 20 and one of the inner walls of the accommodating cavity 11. In this case, the number of fixing members 30 is set to one. Of course, the first wall may also be two or more inner walls of the accommodating cavity 11, that is, the fixing member 30 may also be supported between the electrode assembly 20 and two or more inner walls of the accommodating cavity 11 at the same time. In this case, two or more fixing members 30 are correspondingly provided.

[0063] In a specific embodiment, a single fixing member 30 is provided and supported between the electrode assembly 20 and one of the cavity inner walls. The fixing member 30 supports and stably positions the electrode assembly 20 within the accommodating cavity 11. Furthermore, the fixing member 30 also serves as a position limiter for the electrode assembly 20, effectively limiting expansion and deformation of the electrode assembly 20.

[0064] Furthermore, a liquid flow channel 31 is formed through the fixing member 30 along the thickness direction of the first wall. The electrode assembly 20 and the fixing member 30 are sequentially placed in the accommodating cavity 11, and the accommodating cavity 11 is filled with electrolyte. The liquid flow channel 31 formed through the fixing member 30 allows the electrolyte to flow smoothly through the accommodating cavity 11. On the one hand, the electrolyte can more evenly infiltrate the electrode assembly 20, and on the other hand, when the electrolyte level changes, the electrolyte distribution in the accommodating cavity 11 is more uniform.

[0065] When the fixing member 30 is supported between the electrode assembly 20 and the inner wall of the corresponding accommodating cavity 11, the surface of the fixing member 30 in contact with the electrode assembly 20 is the supporting surface, and the area of ​​the supporting surface accounts for at least 50% of the surface area of ​​the electrode assembly 20 in contact with the fixing member 30. In other words, the area of ​​the supporting surface is not less than 50% of the surface area of ​​the electrode assembly 20 in contact with the fixing member 30.

[0066] In this way, the contact area between the supporting surface and the electrode assembly 20 is larger, which can form a larger area of ​​support for the electrode assembly 20, making the supporting effect of the fixing member 30 on the electrode assembly 20 more stable.

[0067] Thus, the provision of the fixing member 30 not only limits the expansion and deformation of the electrode assembly 20, but also reduces the probability of the electrode assembly 20 shaking inside the housing 10 and causing damage to the electrode assembly 20. Furthermore, because the fixing member 30 is provided with a liquid passage 31 extending therethrough, the electrolyte in the accommodating cavity 11 can flow smoothly through the liquid passage 31 within the accommodating cavity 11. This provides more ample storage space for the electrolyte, reduces the probability of problems such as excessive hydraulic pressure or electrolyte overflow inside the housing 10, and ensures more stable performance of the battery cell 100.

[0068] In some embodiments, the area of ​​the support surface accounts for 70% to 100% of the surface area of ​​the electrode assembly 20 in contact with the support surface.

[0069] Furthermore, the area of ​​the supporting surface is not less than 70% of the surface area of ​​the electrode assembly 20 in contact therewith, and not greater than 100% of the surface area of ​​the electrode assembly 20 in contact therewith. For example, the supporting surface can completely cover the surface of the electrode assembly 20 in contact therewith, that is, the area of ​​the supporting surface is equal to 100% of the surface area of ​​the electrode assembly 20 in contact therewith. In this way, the supporting surface can fully cover the surface of the electrode assembly 20, so that the fixing member 30 can be more stably supported between the electrode assembly 20 and the inner wall of the accommodating cavity 11, further improving the supporting effect.

[0070] Thus, through the above structure, the contact area between the supporting surface and the corresponding surface of the electrode assembly 20 is increased, further improving the supporting effect of the fixing member 30 on the electrode assembly 20.

[0071] In some embodiments, the liquid passage 31 includes a main flow channel 311 extending through the thickness direction of the first wall, and the volume of the main flow channel 311 accounts for at least 50% of the volume of the fixing member 30 .

[0072] Specifically, the mainstream channel 311 is set to penetrate along the thickness direction of the first wall, that is, one end of the mainstream channel 311 is connected to the first wall, and the other end is connected to the electrode assembly 20, so that the electrolyte or other fluid in the accommodating cavity 11 can pass through the mainstream channel 311 smoothly.

[0073] Furthermore, the volume of the mainstream channel 311 accounts for at least 50% of the volume of the fixing part 30. Specifically, the fixing part 30 can be divided into a through hole part and a solid part, wherein the through hole part is the mainstream channel 311 part, and the solid part is the other part of the fixing part 30 where no through hole is opened.

[0074] When there is only one main flow channel 311, the volume of the main flow channel 311 accounts for greater than or equal to 50% of the total volume of the fixing member 30. When there are two or more main flow channels 311, the total volume of all the main flow channels 311 accounts for greater than or equal to 50% of the total volume of the fixing member 30.

[0075] Therefore, on the basis of ensuring the supporting function of the fixing member 30 , the electrolyte or other fluid can flow smoothly in the accommodating cavity 11 .

[0076] In addition, the shape of the main flow channel 311 can be, but is not limited to, a rectangle, a cylinder, a cone or other shapes, which will not be described in detail here.

[0077] Through the above structure, the fixing member 30 can provide stable support between the electrode assembly 20 and the first wall on the one hand, and on the other hand, the mainstream channel 311 opened on the fixing member 30 can also realize the smooth flow of electrolyte or other fluids in the accommodating cavity 11, providing a larger accommodating space for electrolyte or other fluids.

[0078] like Figure 3 、 Figure 4 as well as Figure 5 As shown, in some embodiments, the liquid channel 31 also includes a branch channel 312 connected to the main channel 311, and the branch channel 312 is arranged to pass through the fixing member 30 along a direction intersecting with the thickness direction of the first wall. The total volume of the main channel 311 and the branch channel 312 accounts for at least 80% of the volume of the fixing member 30.

[0079] Specifically, the branch channel 312 can be provided through the first wall in a direction intersecting the thickness direction, or can be provided through the first wall in a direction perpendicular to the thickness direction. The branch channel 312 is connected to the main channel 311, allowing the liquid passage 31 in the fixing member 30 to be connected in different directions, such as up, down, left, and right, to facilitate smoother flow of the electrolyte.

[0080] Furthermore, one or more branch channels 312 may be provided. When there is one branch channel 312, the sum of the volume of the branch channel 312 and the total volume of all the main channels 311 accounts for greater than or equal to 80% of the total volume of the fixing member 30. When there are multiple branch channels 312, the sum of the total volume of all the branch channels 312 and the total volume of all the main channels 311 accounts for greater than or equal to 80% of the total volume of the fixing member 30.

[0081] In this way, the electrolyte can flow in all directions in the accommodating cavity 11 through the main flow channel 311 and the branch flow channel 312, making the electrolyte flow smoother.

[0082] It is understandable that the shape of the branch channel 312 can be, but is not limited to, a rectangle, a cylinder, a cone or other shapes, which will not be described in detail here.

[0083] Through the above structure, the electrolyte can flow in all directions in the containing chamber 11 through the main flow channel 311 and the branch flow channel 312, further increasing the containing space of the electrolyte.

[0084] like Figure 6 As shown, in some embodiments, in a direction intersecting the support surface, a ratio between a height H1 of the fixing member 30 and a height H2 of the housing 10 ranges from 0.03 to 0.4.

[0085] Specifically, the height of the fixing part 30 needs to take into account the machinability of the fixing part 30 itself and the height capacity bottleneck of the shell 10 to ensure that the basic electrolyte circulation space can be met, and it is necessary to ensure that the explosion-proof valve will not open due to excessive hydraulic pressure caused by the full filling process of the electrolyte.

[0086] Furthermore, while meeting the rebound ratio of different metal negative electrode systems, it is necessary to ensure that the battery cell 100 has the advantage of volume energy density, and the limitation in the height direction is the key to meeting the support of mechanical parts and the stability of the internal structure.

[0087] Based on this, the ratio of the height H1 of the fixing member 30 to the height H2 of the shell 10 is set to the above range, which effectively improves the volume energy density of the battery cell 100 while improving the flow performance of the electrolyte inside the shell 10 and the liquid flow channel 31.

[0088] In some embodiments, in a direction intersecting the support surface, a ratio between a height H1 of the fixing member 30 and a height H2 of the housing 10 ranges from 0.03 to 0.25.

[0089] As a specific embodiment, setting the ratio between the height H1 of the fixing member 30 and the height H2 of the shell 10 to the above range can further optimize the rebound ratio of the metal negative electrode system, further expand the volume energy density advantage of the battery cell 100, and further improve the internal structure stability and reliability.

[0090] In some embodiments, the ratio of the volume of the fixing member 30 to the volume of the accommodating cavity 11 ranges from 5% to 40%.

[0091] Specifically, the volume proportion of the fixing member 30 in the accommodating cavity 11 will affect the size of the electrolyte circulation space in the accommodating cavity 11 and the overall volume energy density of the battery cell 100 .

[0092] When the ratio of the volume of the fixing member 30 to the volume of the accommodating chamber 11 is set within the above range, it not only satisfies the basic electrolyte flow space and reduces the probability of the explosion-proof valve opening due to excessive hydraulic pressure during full charging, but also meets the rebound ratio of different metal negative electrode systems, thereby improving the volumetric energy density advantage of the battery cell 100.

[0093] In some embodiments, the ratio of the volume of the fixing member 30 to the volume of the accommodating cavity 11 ranges from 10% to 25%.

[0094] As a specific embodiment, the ratio between the volume of the fixing part 30 and the volume of the accommodating cavity 11 is set to the above range. On the premise of meeting the basic electrolyte circulation space, it can further reserve the space requirement for gas production during the circulation of the electrode assembly 20, thereby improving the life cycle of the battery cell 100.

[0095] Furthermore, the above range can optimize the rebound ratio of the metal negative electrode system and further expand the volume energy density advantage of the battery cell 100 .

[0096] Please also refer to Figure 1 and Figure 6 In some embodiments, the housing 10 includes a body 12 and a top cover 13. The top cover 13 is a sealing cover disposed on the opening of the body 12. The two together enclose a receiving cavity 11. The first wall is a side surface of the top cover 13 facing the interior of the receiving cavity 11.

[0097] Specifically, the housing 10 includes a body 12 and a top cover 13. The body 12 is a hollow structure with one end open. The top cover 13 is sealed over the opening of the body 12, and the two together form a receiving cavity 11. First, the electrode assembly 20 and the fixing member 30 are placed in sequence within the receiving cavity 11, with the fixing member 30 supported between the electrode assembly 20 and the corresponding inner wall of the receiving cavity 11. Then, the top cover 13 is sealed over the opening of the body 12.

[0098] Furthermore, the electrolyte is filled into the accommodating cavity 11 from the injection hole on the top cover 13 . After the filling is completed, the injection hole is sealed, and the assembly of the battery cell 100 is completed.

[0099] The first wall is the surface of the top cover 13 facing the interior of the accommodating chamber 11. In other words, the mounting position is set between the electrode assembly 20 and the top cover 13. Specifically, the electrode assembly 20 and the top cover 13 are spaced apart to form the mounting position. The fixing member 30 is then positioned at the mounting position so that the fixing member 30 is supported between the electrode assembly 20 and the top cover 13.

[0100] Through the above structure, during the assembly process, the electrode assembly 20 is first set in the accommodating cavity 11, and then the fixing member 30 is set on the side surface of the electrode assembly 20 facing the opening, and finally the top cover 13 sealing cover is set at the opening, so that the battery cell 100 can be assembled, which is convenient for operation.

[0101] In some embodiments, an electrode terminal 14 is provided on the top cover 13 , and a first electrode tab 21 and a second electrode tab 22 are formed on the electrode assembly 20 . The first electrode tab 21 and the second electrode tab 22 are both arranged toward the top cover 13 and electrically connected to the electrode terminal 14 through the liquid channel 31 .

[0102] Specifically, the electrode terminal 14 is a structure used to electrically connect to the electrode assembly 20 and enable energy output and input of the battery cell 100. The electrode terminal 14 includes a positive electrode terminal 14 and a negative electrode terminal 14. The electrode assembly 20 has a first electrode tab 21 and a second electrode tab 22. The first electrode tab 21 and the second electrode tab 22 are respectively the positive electrode tab and the negative electrode tab. The positive electrode tab is electrically connected to the positive electrode terminal 14, and the negative electrode tab is electrically connected to the negative electrode terminal 14.

[0103] The first electrode tab 21 and the second electrode tab 22 are arranged upward and toward the top cover 13. The first electrode tab 21 and the second electrode tab 22 pass through the liquid passage 31 and are electrically connected to the corresponding electrode terminal 14. Therefore, the liquid passage 31 not only enables the circulation of electrolyte, but also allows the first electrode tab 21 and the second electrode tab 22 to pass through smoothly and be electrically connected to the electrode terminal 14.

[0104] Through the above structure, the first and second tabs 21, 22 are electrically connected to the electrode terminals 14 on the top cover 13, enabling smooth energy input and output from the battery cell 100. Furthermore, the liquid passage 31 on the fixing member 30 not only facilitates the flow of electrolyte but also allows the first and second tabs 21, 22 to pass through and be electrically connected to the electrode terminals 14.

[0105] In some embodiments, the body 12 has a first side wall 15 and a second side wall 16 that are oppositely disposed and intersect with the top cover 13. Electrode terminals 14 are provided on the first side wall 15 and the second side wall 16. A first electrode tab 21 and a second electrode tab 22 are formed at opposite ends of the electrode assembly 20, respectively. The first electrode tab 21 is disposed toward the first side wall 15 and is electrically connected to the electrode terminal 14 on the first side wall 15. The second electrode tab 22 is disposed toward the second side wall 16 and is electrically connected to the electrode terminal 14 on the second side wall 16.

[0106] Specifically, the body 12 has a bottom wall and multiple side walls, each of which is perpendicular to the bottom wall and surrounds the periphery of the bottom wall. The first side wall 15 and the second side wall 16 are parallel and opposite to each other. When the top cover 13 is sealed over the opening of the body 12, the first side wall 15 and the second side wall 16 are perpendicular to the top cover 13.

[0107] The positive electrode terminal 14 and the negative electrode terminal 14 are respectively disposed on the first side wall 15 and the second side wall 16. The electrode assembly 20 is provided with a first electrode tab 21 and a second electrode tab 22 at opposite ends thereof. When the electrode assembly 20 is placed in the accommodating cavity 11, the first electrode tab 21 is disposed toward the first side wall 15 so that the first electrode tab 21 can be electrically connected to the electrode terminal 14 on the first side wall 15. The second electrode tab 22 is disposed toward the second side wall 16 so that the second electrode tab 22 can be electrically connected to the electrode terminal 14 on the second side wall 16.

[0108] Through the above structure, the electrode assembly 20 has tabs on both sides, and the first tab 21 and the second tab 22 can be electrically connected to the electrode terminal 14 through a flexible connection. First, when the electrode assembly 20 is set in the accommodating cavity 11, the liquid level of the electrolyte is parallel to the top cover 13, and the cross-section of the electrode assembly 20, that is, the end surface formed with the first tab 21 and the second tab 22, is perpendicular to the liquid level of the electrolyte. In this way, the electrolyte can better penetrate into the interior of the electrode assembly 20 through the cross-section, and the electrolyte can be better absorbed. In addition, the first tab 21 and the second tab 22 are arranged toward the first side wall 15 and the second side wall 16, and the fixing member 30 is supported between the electrode assembly 20 and the top cover 13, so that the support surface and the electrode assembly 20 can be more stably fitted, thereby improving the support effect.

[0109] In addition, the explosion-proof valve or other exhaust structure of the battery cell 100 is usually set on the top cover 13. The above structure realizes the left and right terminal ears, which can realize the gas and electricity separation of the battery cell 100 and further improve the safety performance of the battery cell.

[0110] In some embodiments, a ventilation hole 17 communicating with the accommodating cavity 11 is formed through the top cover 13 , and a ventilation component (not shown in the figure) is provided in the ventilation hole 17 , which is configured to enable one-way ventilation from the inside of the accommodating cavity 11 to the outside.

[0111] Specifically, the vent assembly may include a breathable membrane, which allows gas within the accommodating cavity 11 to be exhausted to the outside, thereby maintaining an acceptable internal pressure within the accommodating cavity 11 and improving the stability of the battery cell 100. At the same time, the breathable membrane can also block external liquids or other impurities. In other words, the breathable membrane can achieve one-way exhaust from the interior of the accommodating cavity 11 to the outside. The structure and materials of the breathable membrane can be designed with reference to existing technologies and are not described in detail here.

[0112] Furthermore, the ventilation component may also include a one-way valve. The one-way valve is arranged in the ventilation hole 17, and the one-way valve can be opened in one direction to discharge gas from the inside of the accommodating chamber 11 to the outside, and can block gas, liquid or other impurities outside the accommodating chamber 11.

[0113] Through the above structure, one-way exhaust from the inside to the outside of the accommodating chamber 11 can be achieved, so that the internal pressure of the accommodating chamber 11 remains stable, and the stability of the battery cell 100 is improved.

[0114] In some embodiments, the electrode assembly 20 is a cathode-less electrode assembly.

[0115] It should be noted that a negative electrode-free electrode assembly refers to an electrode assembly 20 that is not actively provided with a negative electrode active material on the negative electrode side. For example, no negative electrode active material is provided on the negative electrode current collector. During the first charge, the ions obtain electrons on the negative electrode side and are deposited on the surface of the negative electrode current collector to form a metal phase. During discharge, the metal can be converted into metal ions and return to the positive electrode, realizing cyclic charge and discharge. Compared with other electrode assemblies, a negative electrode-free electrode assembly is applied to a battery cell 100. Since there is no negative electrode active material, the battery cell 100 can obtain a higher energy density.

[0116] The metal may be sodium or other metals. When metallic sodium is used, the battery cell 100 formed is a negative electrode-free sodium secondary battery.

[0117] When using a negative electrode-less electrode assembly, since the negative electrode current collector is not coated with negative active material, its ability to retain electrolyte is weaker, and the electrode assembly 20 will deform more during cycling. This not only affects the performance of the electrode assembly 20 itself, but also causes greater changes in the electrolyte level within the accommodating cavity 11.

[0118] Thus, by adopting the above structure, the fixing member 30 can provide stable support for the electrode assembly 20, play a certain limiting role, and reduce the probability of expansion and deformation of the electrode assembly 20. In addition, the fixing member 30 supports the electrode assembly 20, and can also improve the stability of the electrode assembly 20 in the accommodating cavity 11, and reduce the probability of the electrode assembly 20 shifting or shaking during recycling. On the other hand, the liquid channel 31 provided on the fixing member 30 can provide a circulation channel for the electrolyte, provide a larger storage space for the electrolyte, and effectively improve the problem of excessive hydraulic pressure in the accommodating cavity 11 and reduce the probability of electrolyte overflow.

[0119] Based on the same concept as the above-mentioned battery cell 100 , the present application further provides a battery, including the above-mentioned battery cell 100 .

[0120] Based on the same concept as the above-mentioned battery, the present application also provides an electrical device, including the above-mentioned battery.

[0121] According to one or more embodiments, during the assembly of the battery cell 100, the electrode assembly 20 can first be placed within the accommodating cavity 11. A first electrode tab 21 and a second electrode tab 22 are formed on opposite sides of the electrode assembly 20, such that the first electrode tab 21 is disposed opposite the first sidewall 15 of the body 12 and electrically connects the first electrode tab 21 to the electrode terminal 14 on the first sidewall 15. The second electrode tab 22 is disposed opposite the second sidewall 16 of the body 12 and electrically connects the second electrode tab 22 to the electrode terminal 14 on the second sidewall 16.

[0122] Furthermore, the fixing member 30 is disposed on the surface of the electrode assembly 20 facing the opening of the accommodating cavity 11, and the top cover 13 is then sealed against the opening of the accommodating cavity 11, so that the fixing member 30 is stably supported between the electrode assembly 20 and the top cover 13. This makes the electrode assembly 20 more stable within the accommodating cavity 11, reducing the probability of the electrode assembly 20 shifting or shaking. The fixing member 30 also acts as a limiter for the electrode assembly 20, effectively suppressing expansion and deformation of the electrode assembly 20.

[0123] In addition, when the liquid level of the electrolyte changes, the electrolyte can flow through the liquid passage 31 on the fixing member 30 , thereby accommodating more electrolyte and making the electrolyte more evenly distributed in the accommodating cavity 11 .

[0124] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0125] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A battery cell, characterized in that: include: The housing has a receiving cavity, wherein the receiving cavity has a first wall; an electrode assembly, disposed in the accommodating cavity; and a fixing member disposed between the electrode assembly and the first wall and supported by the electrode assembly, wherein the fixing member is provided with a liquid passage extending through the fixing member along the thickness direction of the first wall; The fixing member includes a supporting surface in contact with the electrode assembly, and an area of ​​the supporting surface accounts for at least 50% of a surface area of ​​the electrode assembly in contact with the fixing member.

2. The battery cell according to claim 1, wherein: The area of ​​the supporting surface accounts for 70% to 100% of the surface area of ​​the electrode assembly in contact with the supporting surface.

3. The battery cell according to claim 1, wherein: The liquid passage includes a main flow channel extending through the first wall in a thickness direction, and the volume of the main flow channel accounts for at least 50% of the volume of the fixing element.

4. The battery cell according to claim 3, characterized in that The liquid passage also includes a branch channel connected to the main channel, and the branch channel is arranged to penetrate the fixing member along a direction intersecting with the thickness direction of the first wall. The total volume of the main channel and the branch channel accounts for at least 80% of the volume of the fixing member.

5. The battery cell according to claim 1, characterized in that In a direction intersecting the support surface, a ratio between a height of the fixing member and a height of the housing is in a range of 0.03 to 0.

4.

6. The battery cell according to claim 5, characterized in that In a direction intersecting the support surface, a ratio of a height of the fixing member to a height of the housing is in a range of 0.03 to 0.

25.

7. The battery cell according to claim 1, characterized in that The ratio of the volume of the fixing member to the volume of the accommodating cavity ranges from 5% to 40%.

8. The battery cell according to claim 7, characterized in that The ratio of the volume of the fixing member to the volume of the accommodating cavity is in a range of 10% to 25%.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The housing includes a body and a top cover, wherein the top cover sealing cover is arranged on the opening of the body, and the two together enclose the accommodating cavity; Wherein, the first wall is a side surface of the top cover facing the interior of the accommodating cavity.

10. The battery cell according to claim 9, characterized in that The top cover is provided with an electrode terminal, and the electrode assembly is formed with a first electrode tab and a second electrode tab. The first electrode tab and the second electrode tab are both arranged toward the top cover and are electrically connected to the electrode terminal through the liquid passage.

11. The battery cell according to claim 9, characterized in that The body has a first side wall and a second side wall that are oppositely arranged and intersect with the top cover, and the first side wall and the second side wall are both provided with electrode terminals; In which, the opposite ends of the electrode assembly form a first electrode tab and a second electrode tab respectively, the first electrode tab is arranged toward the first side wall and electrically connected to the electrode terminal on the first side wall, and the second electrode tab is arranged toward the second side wall and electrically connected to the electrode terminal on the second side wall.

12. The battery cell according to claim 10 or 11, characterized in that: The top cover is provided with an air vent which is in communication with the accommodating cavity. A air vent component is provided in the air vent. The air vent component is configured to achieve one-way air permeability from the inside of the accommodating cavity to the outside.

13. The battery cell according to claim 1, characterized in that The electrode assembly is a negative electrode assembly.

14. A battery, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 13.

15. An electrical device, characterized in that: Comprising the battery of claim 14.

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